Hydroelectric power plants are part of the hydroelectric complex. A hydroelectric complex is a complex of hydraulic structures that ensure the use of water resources to obtain electrical energy, water supply, irrigation, as well as flood protection, improving the conditions of navigation, fish farming, recreation, etc.
Composition and purpose of HPP structures. If the main task of creating a hydroelectric complex is to generate electricity, then it is usually called a hydroelectric power station or a hydropower facility. In the complex of structures of the hydroelectric complex, the main and auxiliary structures are distinguished. To ensure the production of construction and installation works during the construction period, temporary structures are erected.
The main structures, depending on the functions performed, are divided into:
water and drainage structures,
designed, depending on the scheme of the hydroelectric power station, to create a reservoir, all or part of the head of the hydroelectric power station, pass operating costs to the downstream, including floods (including dams and spillways of various types), as well as for discharging ice, slush, washing sediments (including for these purposes in some cases special devices). On high-water rivers, the maximum flood discharges can reach 100 thousand m3 / s or more. So, at the world's largest hydroelectric power station "Three Gorges" on the river. The Yangtze (China) hydroelectric facilities are designed to allow the maximum design flood of 102.5 thousand m3 / s at the FPU, at the Cheboksarskaya HPP on the Volga the maximum design flow with a security of 0.01% is 48 thousand m3 / s, at Dneproges - 25.9 thousand m3 /s.Power facilities designed to generate electricity and issue it to the power system and include water intakes; conduits supplying water from the upstream to the hydro turbines in the HPP building and diverting water from the HPP building to the downstream; HPP buildings with power equipment (hydro turbines, hydro generators, transformers, etc.), mechanical, handling, auxiliary equipment, control system; open (ORU) or closed (ZRU) distribution devices for receiving and distributing electricity to the power system, as well as emergency shutdown of power lines.
Shipping and timber-rafting facilities designed to pass ships, rafts through the hydroelectric complex and include locks, ship lifts with inlet and outlet channels, boats, etc.
Water intakes for irrigation, water supply, providing the necessary water supply and including water intakes, pumping stations, etc.
Fish-passing and fish-protecting structures designed to pass passage fish species to spawning grounds in the upstream and in the opposite direction, and including fish passages and fish elevators.
Transport facilities designed to connect the structures of the hydroelectric complex with each other, as well as to pass roads and railways through them, and including bridges, highways and railways, etc.
Depending on the natural conditions of the location of the hydroelectric complex (hydrological, topographic, geological, climatic), the scheme for creating pressure, the type of hydroelectric power station, some of the main structures of the hydroelectric complex can be combined with each other (for example, spillway buildings of a hydroelectric power station, where the hydroelectric power station building is combined with a spillway).
Auxiliary structures are designed to provide the necessary conditions for the normal operation of the hydroelectric complex and the work of maintenance personnel and include administrative buildings, water supply systems, sewage systems, etc.
Temporary structures necessary for the production of construction and installation works can be divided into two groups.
The first group includes structures that ensure the flow of the river during construction, bypassing pits and structures under construction and protecting them from flooding and including construction channels, conduits, tunnels, dams, water reduction systems, etc.
The second group includes auxiliary production enterprises, including concrete plants with warehouses of cement, aggregates for concrete, reinforcing, woodworking and mechanical shops, mechanization and motor transport bases, warehouses, temporary roads, temporary power supply systems, communications, water supply, etc.
In many cases, part of the temporary structures after construction is completed is used during the operation of the HPP. So, from the structures of the first group, construction channels and tunnels can be included in whole or in part in the spillways or conduits of hydroelectric power plants, and lintels in the structure of dams.
The structures of the second group can be fully or partially used as the initial infrastructure of territorial production complexes based on hydroelectric power plants.
To ensure reliable and durable operation of HPPs under operating conditions, taking into account integrated use, to achieve the maximum economic effect by reducing costs, reducing construction time and accelerating the commissioning of hydroelectric units, it is important to choose a rational layout and types of structures based on natural conditions, reservoir parameters and hydroelectric power stations, operating modes.
Taking into account the long construction periods of large HPPs, reaching 5–10 years, it is usually envisaged to erect structures and put hydroelectric units into operation in stages with unfinished structures, low pressures, which increases economic efficiency.
HPPs and PSPPs are divided into:
According to the method of creating pressure, based on the basic schemes for the use of hydraulic energy at HPPs, the location of the HPP building as part of the structures: HPP with run-of-river buildings; HPP with dam buildings; diversion HPPs.
In terms of installed capacity (for pumped storage power plants in terms of power in generator mode) for: powerful - more than 1000 MW, medium power from 30 to 1000 MW, low power - less than 30 MW.
By head (maximum): high-pressure - more than 300 m, medium-pressure - from 30-50 to 300 m, low-pressure - less than 30-50 m.
Hydroelectric power stations with channel buildings are usually used on flat rivers on soft and rocky foundations with heads up to 50 m and are characterized by the fact that the hydroelectric power station buildings are part of the pressure front and perceive water pressure from the upstream side. The complex of HPP structures usually includes concrete structures, including the HPP building, weir dam and shipping lock, and earthen dams, which form most of the pressure front. In many cases, the run-of-river buildings of HPPs are combined with spillways. The use of combined run-of-river buildings at the Kievskaya, Kanevskaya, Dniesterskaya (Ukraine), Plyavinskaya (Latvia), Saratovskaya (Russia) HPPs and a number of others made it possible to abandon spillway concrete dams, reduce the front of concrete structures and obtain significant savings. The choice of the general layout of HPP structures with run-of-river buildings used on high-water rivers, where the estimated flood discharges during the construction period can reach 10–20 thousand m3 / s, is significantly influenced by the scheme for skipping river discharges during the construction period.
Depending on the location of the concrete structures of the HPP, the following layouts are distinguished (Fig. 4.1):
Coastal and floodplain layout.
Such layouts are distinguished by the fact that the main concrete structures (hydroelectric power station building, spillway dam, etc.) are located outside the riverbed, their excavation is protected by cofferdams, and during their construction, construction costs, including floods, are passed along the riverbed. When concrete structures are erected, the channel is blocked by a blind dam, most often earthen, and the river flows are passed through concrete structures. With a coastal layout, the height of the lintels is less, and when the pit is located within the coast area that is not flooded by floods during the construction period, there is no need for lintels at all. A significant disadvantage of the coastal layout is the need to perform large volumes of earthworks for excavation in the pit, inlet and outlet channels. With a floodplain layout, the pit of concrete structures is located in the floodplain closer to the channel, which leads, on the one hand, to an increase in the height of the lintels that enclose the pit, and, on the other, to a decrease in the amount of excavation work.
Channel arrangement. With this arrangement, concrete structures are placed in the riverbed. In this case, the following schemes for their construction are used:
In one pit, fenced with cofferdams, with the passage of construction costs through a channel made in the shore.
In two (rarely in three) stages, when part of the channel is fenced off with jumpers and concrete structures of the 1st stage are erected in it, and construction costs are passed through the other part of the channel. When the structures of the 1st stage are erected, the flow of the river is passed through them, and the other part of the channel is protected by jumpers and concrete structures of the 2nd stage are erected.
Mixed layout. With this arrangement, concrete structures are placed partly in the channel and on the shore (in the floodplain) or in the channel over its entire width and partly on the shore (in the floodplain).
The choice of the HPP layout option in each specific case is determined by the natural conditions of the HPP site, provision of favorable operating conditions, reduction of construction time, cost of the hydroelectric complex, and is made on the basis of a technical and economic comparison of options.
As an example, in fig. 4.2 shows the layout of the Kyiv HPP. The concrete structures located on the right bank include: a run-of-river HPP building with 20 horizontal capsular hydroelectric units with a total installed capacity of 360 MW with an average annual output of 0.64 billion kWh per year, combined with surface spillways, a single-chamber lock. The earthen dam blocking the channel and the left-bank dam have a total length of about 54 km. The maximum head of the HPP is 11.8 m, the calculated one is 7.6 m. The calculated maximum flood flow through the HPP facilities is 14.8 thousand m3/s, and the maximum specific flow rate at the water break is 90 m3/s. In the conditions of a sandy base, to ensure reliable operation of the run-of-river building of the HPP, impervious measures are provided, including a clayey slope, a sheet pile curtain under the foundation slab of the HPP building, behind which a drainage is arranged, connected to the downstream. To prevent dangerous erosion of the bottom during the operation of the hydroelectric power station and the passage of floods in the downstream, a fastening was made, including a water break and an apron made of reinforced concrete slabs with a thickness of 2.5 to 1.5 m and a ladle filled with rock fill, which, if an erosion funnel forms, will prevent further erosion.
The complex of facilities includes the Kyiv PSP, located on the banks of the Kyiv reservoir, 3.5 km from the HPP.
HPPs with dam buildings are built on flat and mountain rivers, mainly on rocky foundations with heads from 30 to 300 m, and are characterized by the fact that the HPP building is located behind the dam.
The length of pressure conduits and the layout of the HPP building depend on the type, height and other parameters of the dam, the natural conditions of the site.
In the conditions of lowland rivers, the layout of HPPs with dam buildings is similar to the layouts with run-of-river buildings and differs from them in that there is a concrete dam with a water intake and penstocks (station dam) in front of the building, separated from the HPP building by an expansion joint. An interesting example of such a layout is the Dneproges (Fig. 4.3).
After the construction of the Kremenchug hydroelectric power station with a reservoir with a useful capacity of 9 km3, which provides seasonal regulation of the Dnieper runoff, the estimated maximum flood flow of the Dneproges in the conditions of regulated flow decreased from 40 to 25.9 thousand m3 / s, due to which part of the spillways (spans) of the dam was released, which made it possible to use them as water inlets of the second HPP building with a total capacity of 888 MW and increase the total capacity of the Dneproges to 1595 MW. Water is supplied to each turbine from two spans (water inlets) through two reinforced concrete pressure pipelines, supported by a dam and separated from the HPP building by an expansion joint.
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Rice. 4.3. Dneproges: a - plan; b, c – turbine hall of HPP-1 and HPP-2, respectively; 1 - HPP-1 building; 2 - gravity dam; 3 - HPP-2 building; 4 - gateway
At higher pressures, usually in the conditions of mountain rivers, the layout of hydroelectric power plants with concrete dams and dams made of soil materials has features.
Layouts with concrete dams, as a rule, are carried out as channel or mixed with the placement of the HPP building behind a gravity, buttress or arch dam and are characterized by the location of pressure conduits in the body of the dam, on its upstream or downstream sides (Fig. 4.4). The structure of the hydroelectric complex includes a station dam with a dam building of a hydroelectric power station, a spillway dam and blind dams, which can be concrete and made of soil materials.
In narrow sections, there are difficulties with the placement of the building of the hydroelectric power station and the spillway. In these cases, the spillway can be performed separately on the shore (for example, the Chirkeyskaya HPP) or in the form of a surface spillway located on the floor of the hydroelectric power plant near the dam building (for example, the Toktogulskaya HPP). It is extremely rare that the turbine hall of a hydroelectric power station is located in the body of a dam (for example, the Monteinar hydroelectric power station in France, where the turbine hall with four hydraulic units with a total capacity of 320 MW is located in a cavity inside an arch-gravity dam 153 m high and 210 m long along the crest, and the surface spillway is on the downstream side dams). Such built-in buildings, placed in a cavity inside a concrete dam (see Fig. 4.4, d), constitute a separate group and conditionally belong to the dam buildings.
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Rice. 4.4. HPP layouts with dam buildings and concrete dams: a - channel layout - HPP "Three Gorges": 1 - spillway dam; 2 - left-bank and right-bank station dams and HPP buildings; 3 - ship lift; 4 - two-line gateway; b - mixed layout - HPP Itaipu: 1 - left-bank dam made of soil materials; 2 - channel for skipping construction costs; 3 - temporary spillway; 4 - bottom jumper; 5 - HPP building; 6 - top jumper; 7 and 8 - concrete dam; 9 - spillway; 10 - right-bank dam made of soil materials; c - options for the location of pressure conduits of HPP with a dam building; d - option with built-in building
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Rice. 4.5. Krasnoyarsk HPP: a - plan; b - cross-section of the station dam and the HPP building; 1 - HPP building; 2 – station dam; 3 - spillway dam; 4–7 – blind dams; 8 - mounting platform; 9 and 10 - upstream and downstream shipping routes; 11 - rotary device; 12 - ship's camera; 13 - wave protection wall
In relatively wide sections, construction is usually carried out in two phases with the construction of a concrete spillway dam (or part of the dam) in the first place and the passage of construction costs through the cramped riverbed, and after its blocking, in the second turn - through the spillway openings in the constructed spillway dam and the completion of construction hydroelectric facilities.
In narrow sections, to pass construction costs, a construction tunnel is being built, which, under operating conditions, can be used to construct a flood spillway.
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Rice. 4.6. Chirkeyskaya HPP: a – cross section; b - plan; 1 - dam; 2 - water intake; 3 - pressure conduits; 4 - HPP building; 5 - access tunnel; 6 - operational spillway, combined with a construction tunnel
Examples of HPPs with a dam building in a relatively wide alignment are the world's largest HPP "Three Gorges" with a capacity of 18.2 million kW (see Fig. 4.4, a), the Itaipu HPP with a capacity of 12.6 million kWh, (see Fig. 4.4, b), Sayano-Shushenskaya HPP with a capacity of 6.4 million kW, Krasnoyarsk HPP with a capacity of 6 million kW with an average annual output of 20.4 billion kWh. The structures of the Krasnoyarsk HPP include a gravity dam with a length of 1065 m and a maximum height of 125 m (Fig. 4.5), consisting of a station and blind dams, a spillway dam, which ensures the passage of a flood flow of 14.6 thousand m3 / s (taking into account the transformation of the flood into reservoir when the level is forced), as well as a ship lift.
An example of a HPP with a dam building in a narrow alignment is the Chirkey HPP with a capacity of 1.0 million kW with an arched dam with a crest length of 333 m and a maximum height of 233 m and with a two-row arrangement of hydraulic units in the building (Fig. 4.6). On the left bank, a tunnel operational spillway was made, designed to pass a flood flow of 3.5 thousand m3 / s.
At the Toktogul HPP with a capacity of 1.2 million kW with a dam building in a narrow alignment with a two-row arrangement of hydraulic units in the HPP building and a gravity dam with a maximum height of 216 m, HPP pressure conduits and a deep spillway are located in the body of the dam, and a surface spillway is located on the lower face of the dam (Fig. 4.7).
In narrow sections with concrete dams and from soil materials, layouts with a coastal and underground HPP building can be used.
The main layouts of HPPs with dams made of soil materials are shown in fig. 4.8. In this case, the HPP building can be located directly behind the dam (a) or the most commonly used layouts with the onshore (b) and underground (c) HPP building are used.
For layouts of HPPs with dams made of soil materials, the coastal placement of operational spillways to pass flood flows is typical: in the form of a coastal surface spillway with a fast flow or a tunnel spillway. Construction tunnels are commonly used to skip construction costs.
A complex of hydropower facilities, including a water intake, conduits, a hydroelectric power station building, made outside the dam, is called the pressure-station unit (NSU) of the hydroelectric power station.
An example of a high-pressure HPP with a dam building and a dam made of earth materials is the Nurek HPP with a capacity of 2.7 million kW with an average annual output of 11.2 billion kWh per year (Fig. 4.9). Water is supplied to the turbines from tower-type water inlets by pressure tunnels. To speed up the commissioning of the HPP, the first three hydroelectric units were operated at reduced pressure, when the dam was built only to a height of 143 m (with a design height of 300 m), for which a temporary water intake and a tunnel were made. During the construction period, the flow of the river was passed through three tiers of construction tunnels located on the left bank. Flood discharges during the operational period (maximum discharge 5.4 thousand m3/with a probability of 0.01%) are passed through a tunnel spillway connected to the end section of the construction tunnel of the third tier.
Diversion HPPs are used in a wide range of heads, ranging from a few meters at small HPPs to up to 2000 m (the Reisseck HPP in Austria has a head of 1767 m), and are usually built in foothill and mountainous areas.
Hydroelectric power station with gravity diversion can be used with minor fluctuations in the water level in the reservoir. At such HPPs, water is supplied from a water intake to a diversion channel running along the coast (under appropriate topographical and geological conditions) or to a non-pressure diversion tunnel.
Hydroelectric power station with pressure diversion is used for both large and minor fluctuations in the water level in the reservoir. At such HPPs, water is supplied from a water intake to a pressure diversion pipeline located on the surface, or to a pressure diversion tunnel (Fig. 4.10). Structures of a diversion HPP, as well as a hydroelectric power plant with a dam-derivation (combined) scheme, in which the pressure is created by a dam and a diversion (see 2.4), include:
The head unit, which is designed to create backwater in the river and direct the flow to the derivation, as well as to clean water from sediment, litter, in some cases from ice, sludge, consists of a dam, a spillway, a water intake, a sump, washing and ice-discharge facilities.
Head units with low-pressure dams, usually built on mountain rivers, have reservoirs with a limited volume, and therefore measures are taken to prevent their filling with sediments. To do this, as part of the hydroelectric complex, a spillway concrete dam equipped with gates is made with a low threshold and a sufficient width of the spillway front, which ensures washing of sediments when flood flows are missed. At in large numbers in the water of suspended sediments, which can lead to rapid abrasion of the flow part of hydraulic turbines, settling tanks are arranged in the form of a chamber in which, with a decrease in the flow rate, suspended particles settle to the bottom and then are removed.
The blind part of the dam can be made of concrete or earth materials. The water intake can be combined with a dam or made on the shore.
Reservoirs usually carry out daily regulation and are characterized by a small drawdown depth, which makes it possible to perform both free-flow and pressure derivation.
The head units with medium and high pressure dams are characterized by a large volume of the reservoir (with the possibility of sediment settling within the dead volume) and a significant drawdown of the reservoir during seasonal or long-term flow regulation. In this regard, the water intakes are deep, and the derivation is pressure.
Dams can be made of concrete (gravitational, buttress, arched) with a spillway and, in many cases, a water intake of a hydroelectric power station, as well as from local materials with a spillway and a water intake located outside the dam body.
Derivative conduits and structures on their route (derivation), which supply water to the station node, are divided into pressure (tunnels, pipelines) and non-pressure (channels, tunnels), along the route of which spillways, siphons and other structures can be arranged.
The station node includes, in case of non-pressure diversion, a pressure basin with a fore-chamber, a water intake, an emergency spillway and, regardless of the type of derivation, common structures: turbine penstocks, if necessary with a surge tank, a power plant building, diverting conduits in the form of a channel or tunnel (pressure or non-pressure), distribution device.
As part of the station node, the HPP buildings are open-shore, underground, and less often semi-underground.
A typical example of a dam-derivation HPP is the Inguri HPP (Georgia) with a capacity of 1.3 million kW (Fig. 4.11), the head unit of which includes an arch dam 271 m high with a flood spillway designed for a flow rate of 1900 m3 / s. The reservoir has a useful volume of 0.68 km3 with a drawdown depth of 70 m. From a deep water intake, designed for a flow rate of 450 m3 / s, a diversion pressure tunnel begins with a diameter of 9.5 m and a length of 15.3 km. The HPP station unit includes a shaft-type surge tank, a butterfly valve room, tunnel turbine conduits, an underground HPP building, a discharge free-flow tunnel and a channel with a total length of 3.2 km.
The total static head of the Inguri HPP, equal to 409.5 m, is formed from the pressure created by the dam (226 m) and the derivation (183.5 m). The calculated head is 325 m, and the average annual output is 5.4 billion kWh per year.
Types of HPP buildings and their main elements. The HPP building is a hydraulic structure in which, with the help of hydropower, electrical, hydromechanical, auxiliary equipment, control systems, the mechanical energy of water is converted into electricity transmitted to the power system to consumers. At the same time, reliable operation, strength and stability of the HPP building under the action of external loads (hydrostatic and hydrodynamic pressure, filtration pressure, temperature, seismic effects, etc.), as well as loads from the operation of process equipment, must be ensured.
The type and design solutions of HPP buildings are determined by the general layout of HPP structures and the main power equipment. Depending on the pressure and working conditions, rotary-blade, axial, radial-axial, diagonal and bucket turbines are installed in the HPP buildings.
The lower part of the building, where the flow path is located, including the spiral chamber, the suction pipe, turbine equipment and a number of technological systems, is called the aggregate part, and the upper part of the building with the upper structure, where the machine room with hydro generators and crane equipment, as well as power transformers, is located. faucet equipment of the water intake (in run-of-river buildings), repair gates of suction pipes and other technological equipment - the supra-aggregate part.
The design and dimensions of the HPP building in plan and height, penetration into the base are significantly affected by the dimensions of the hydraulic unit, the spiral (turbine) chamber and the suction pipe, the penetration of the axis of the hydraulic turbine impeller under the tailwater level, and the number of hydraulic units. As a rule, two or more hydroelectric units are installed in the building of the HPP (for example, in the building of the Saratovskaya HPP - 23 hydroelectric units, Kanevskaya HPP - 24 hydroelectric units), rarely - one hydroelectric unit, since when it is repaired, the HPP completely stops working.
The structure of the HPP building includes an installation site, where the installation of hydroelectric units and their repair during operation are carried out. The assembly site also houses part of the auxiliary systems.
Multi-unit HPP buildings, which are of considerable length, are divided into separate sections by expansion joints: temperature-sedimentary with a soft base, temperature with a rocky base. Thus, the building of the Volzhskaya HPP with a capacity of 2530 MW with 22 hydroelectric units is divided into sections 60 m long, each of which houses two aggregate blocks with rotary-blade turbines with an impeller diameter of 9.3 m (with a design head of 19 m and a power of 115 MW). ).
The block of the mounting platform is usually also separated from the building by a seam.
The aggregate part of the HPP building is characterized by considerable massiveness. It perceives hydrostatic and hydrodynamic pressure in the flow path, loads from equipment and upstream structures of the building and transfers them to the base. Geological conditions have a significant impact on the design of the aggregate part of the building. So, with a rocky base, it is greatly facilitated. In the aggregate part of the building there are systems of technical water supply, drainage of the flowing part, drainage of the building, etc.
The design of the aggregate part depends on the type of HPP building.
In accordance with the types of hydroelectric power plants, there are:
Run-of-river buildings of hydroelectric power stations, which are part of the pressure front and perceive pressure from the upstream side. In run-of-river buildings with a head of up to 50 m, rotary-blade turbines can be used, and with a head of more than 30 m, also radial-axial ones.
Dam buildings located behind the dam, which receives pressure from the upstream side. Water supply to them is carried out by turbine conduits. In dam buildings with a head of 30 to 300 m, mainly radial-axis turbines are used, as well as, under certain conditions, high-pressure rotary-blade turbines (for example, at the Orlik HPP with a head range of 45–71 m and a unit power of 90 MW) and diagonal ones (for example, the Zeya HPP with head range 78.5–97 m and unit power 215 MW).
Shore buildings used in dam and diversion schemes of HPPs practically do not differ from dam buildings.
Underground buildings, which are also used in dam and diversion schemes of HPPs, have discharge tunnels (pressure or non-pressure). In the buildings of diversion HPPs with high heads, radial-axial turbines up to a head of 600 m and bucket turbines from a head of 500 m and above are used. All the above types of buildings are used both in the schemes of hydroelectric power plants and pumped storage power plants.
The main diagrams of the aggregate part of HPP buildings (except for underground HPP buildings) are shown in fig. 4.12. Schemes I and II show the aggregate parts of a low-pressure run-of-river HPP building with vertical hydraulic units and bent suction pipes of an uncombined and combined type, respectively, with deep spillway conduits, and diagrams IV and V show horizontal and inclined hydraulic units of a combined type with a surface spillway.
Scheme III shows the aggregate part of the dam or diversion building of the HPP with a metal turbine (spiral) chamber of circular cross section.
Scheme VII shows the aggregate part of a diversion HPP with low-capacity hydraulic units using vertical conical and socket suction pipes. At the same time, a rectangular cross-section discharge channel is made to drain water.
Scheme VI shows the aggregate part of a diversion hydroelectric power station with bucket (active) hydraulic turbines, which is distinguished by the absence of conventional turbine chambers and suction pipes, due to which the aggregate part is greatly simplified.
The parameters of the supra-aggregate part of the HPP building depend on the design and dimensions of the upper structure.
With a closed-type top structure with a high machine room within the HPP building and the installation site, the most favorable conditions for the operation, installation and repair of the main equipment are provided under various climatic conditions. At the same time, the height and width of the turbine hall are determined both by the conditions for placing the equipment in it, and for its delivery by cranes of the turbine hall to the aggregate block or to the installation site during the installation or repair of the main equipment.
The superstructure usually consists of a supporting frame in the form of a system of columns on which crane beams and floor trusses, walls, slabs and floor roofs are supported.
Most HPP buildings are made with a high turbine hall (Fig. 4.13 - 4.15).
With a semi-open topside structure with a reduced machine room within the HPP building and the installation site, the main equipment is located in the machine room, except for the main heavy-duty crane, which is placed outside it. During installation and repair, the assembly and disassembly of hydraulic units is carried out through a removable ceiling above each hydraulic unit (in the form of removable covers) using an external gantry crane. At large hydroelectric power plants, in most cases, a reduced-capacity crane is installed in a lowered turbine hall, with the help of which installation and repair work is carried out that do not require the use of the main crane (Fig. 4.16 - 4.18).
With an open-type top structure without a machine room, the hydroelectric generator is located under a removable cover, and the rest of the equipment is in the process rooms of the power plant building's aggregate part and the installation site. Installation and repair work is carried out using an external crane. Given the complication of operating conditions, installation and repair of hydraulic units, this type of superstructure is used extremely rarely.
Run-of-river HPP buildings(Fig. 4.19). Run-of-river buildings of HPPs are subject to the same loads as concrete dams, and they are subject to the same requirements for strength, stability, filtration conditions in the base, which are ensured with the appropriate dimensions of the building, impervious and drainage devices in the base. Channel buildings are divided into non-combined and combined with a spillway.
Due to the fact that the flow entering the outlet channel from an uncombined and especially a combined building has excess kinetic energy to prevent erosion, fastening is performed in the outlet channel (see Fig. 4.2).
Rice. 4.17. Run-of-river spillway building with horizontal capsular hydraulic units of the Kyiv HPP: a - cross section; b - machine room; 1 - gantry crane; 2 - capsular hydraulic unit; 3 - groove of the trash grate
The connection between the HPP building and the earthen dam adjacent to it or with the shore is carried out with the help of interface abutments in the form of retaining walls (gravitational, corner, buttress, cellular and other types).
In run-of-river buildings of an uncombined type with vertical hydraulic units, the flow part includes a water intake, a spiral chamber, mainly of a tee section, and a suction pipe, the dimensions of which determine the dimensions of the aggregate block. In this case, the width of the block with a Kaplan turbine can be 2.6–3.2 of the diameter of the turbine impeller (D1). The dimensions of the water intake are determined by the required depth under the ULV, the provision of favorable hydraulic conditions at the inlet and when paired with a spiral chamber, the allowable flow velocities on the grates (usually 0.8–1.2 m/s), the placement of the grate, emergency repair and repair gates , the grooves of which can be combined with the grooves of the lattice. At the inlet section of the water intake, as a rule, a socket with a visor wall is made, which ensures a smooth supply of water.
The deepening of the HPP building under the tailwater level depends on the required deepening of the impeller axis under the tailwater level (suction height) and the size of the suction pipe, as well as the engineering and geological conditions of the foundation.
The main step-up transformers are installed on the floor above the technological premises from the downstream side.
Run-of-river buildings of the combined type, in which, in addition to turbine conduits, spillways are also located, can be made: with bottom spillways placed below the spiral chamber above the suction pipes - Volgogradskaya, Novosibirskaya, Kakhovskaya HPPs (Fig. 4.19, b);
- with bottom spillways and a high intake of turbine conduits - Cheboksarskaya, Golovnaya HPP (see Fig. 4.13);
- with deep spillways located above the spiral chamber (between it and the generator) - Irkutsk, Saratov, Dubossary HPPs (see Fig. 4.16);
- spillway with vertical hydraulic units - Pavlovskaya, Plyavinskaya (see Fig. 4.14), Dniester HPP;
- weirs with horizontal hydraulic units - Kyiv, Kanevskaya HPPs (see Fig. 4.17);
- gobies with the placement of hydroelectric units in the gobies of the spillway dam - Ortochalskaya (Georgia), Wells (USA).
Buildings of the combined type can significantly reduce the length of spillway dams or completely abandon them, which is especially important when building HPPs on soft foundations, reducing construction costs. So, at the Novosibirsk hydroelectric power station, the length of the spillway dam was reduced by 50%. At the Irkutsk, Pavlovskaya, Plyavinskaya, Dniester HPPs, the throughput capacity of the spillways of the HPP building ensures the passage of the estimated flood flow without spillway dams. In combined HPP buildings, the water intake includes a turbine water intake and a water intake part of the spillways.
The disadvantages of such buildings include the complexity of the design, significant additional hydrodynamic loads during the operation of spillways, and the complication of operating conditions.
In buildings of combined type with horizontal capsule units, used at low pressures (up to 25 m), due to the absence of a spiral chamber and the use of a straight-axis conical suction pipe, a significant reduction in the width of the aggregate block and an increase in the foundation of the building footing are achieved. In addition, improving the geometry and hydraulic conditions of the flow path, including the inlet part without a spiral chamber of complex configuration and replacing the bent suction pipe with a straight-axial conical one with higher energy performance, can reduce pressure losses, increase the throughput of a horizontal unit by 20–30% and, accordingly, at the same power, reduce the diameter of the impeller. In general, the use of horizontal capsule units, compared with vertical ones, reduces the width of the aggregate block by up to 35%, increases efficiency. by 2–4%.
Rice. 4.19. Rustic buildings. Cross sections and views from the downstream: a - Kremenchug and b - Kakhovskaya HPP: 1 - foundation slab; 2 - metal sheet pile; 3 - bottom spillway
The surface spillway provides favorable conditions for the passage of floods, and in many cases makes it possible to abandon the installation of a spillway dam. In such buildings, a metal capsule with a hydrogenerator enclosed in it is placed in the flowing part of the building from the upstream side. Access to the capsule is through special cavities in the vertical bull. The installation and dismantling of the hydraulic unit is carried out using an overhead crane, which is located in the engine room under the spillway, and an external gantry crane through hatches with removable covers in the spillway threshold (see Fig. 4.17).
At a number of small hydroelectric power plants, the generator is located openly in the turbine hall, the axis of the hydraulic unit is inclined, and water is supplied to the turbine through a conduit passing under the generator (see Fig. 4.12, scheme V)
Run-of-river buildings of the goby type are used extremely rarely, mainly on rivers that carry a large amount of sediment, providing favorable conditions for the passage of ice, sediment and flood flows through the spillway spans. At the Wells bull-type HPP (USA) with a capacity of 870 MW and a head of 30 m, 10 hydroelectric units are installed in the gobies of the dam, the estimated flood flow is 33.4 thousand m3 / s. The disadvantages of such HPPs include the lack of a common machine room, the lengthening of technological communications and, in general, the complication of operating conditions.
Dam buildings of the hydroelectric power station. In the dam buildings of the HPP, water is supplied to the turbines through turbine conduits (metal or steel-reinforced concrete), passing mainly in the body or on the bottom face of concrete dams, with the placement of the water intake on the upper face of the dams, the HPP building directly adjacent to the dam, and a separate seam (see Fig. 4.3, 4.5–4.7). With dams that are rectilinear in plan, the HPP building is also rectilinear; when it is located behind arched or arch-gravity dams, the HPP building can have a rectilinear or curvilinear outline along an arc corresponding to the outline of the downstream face of the dam.
To ensure a smooth supply of water from the turbine conduit to the spiral chamber, a horizontal section of the conduit with a length of (4–6) D 1 is usually made in front of it, within which technological rooms are arranged with step-up transformers placed on the upper floor.
With dams made of local materials, water is supplied to the turbines through turbine conduits passing through the body of the dam or bypassing it in the form of tunnels or open conduits, with a separate water intake in the upstream and with the power plant building located at some distance from the dam.
Unlike run-of-river dam buildings, they do not perceive the pressure of the upstream, and the pressure transmitted to them through turbine conduits is small, which makes it possible to facilitate the construction of the building.
The spiral chambers of such buildings have a circular cross section and are made of metal or steel-reinforced concrete with metal cladding.
The width of the aggregate block with vertical radial-axial (or diagonal) hydraulic turbines is determined by the dimensions of the turbine (volute) chamber and is at least 4D 1 (impeller diameter).
A typical example of a dam building is the building of the Krasnoyarsk HPP with a total length together with an installation site of 428.5 m, where 12 hydroelectric units with a total capacity of 6 million kW are installed (see Fig. 4.5). The stationary dam has a water intake with 24 intake openings. Water is supplied to the unit through two steel-reinforced concrete conduits with a diameter of 7.5 m.
At the Chirkeyskaya HPP with an arch dam built in a narrow gorge, a reduction in the length of the dam building is achieved by a two-row arrangement of hydraulic units (see Fig. 4.6). Both turbine halls are served by one overhead crane, which is transferred from one turbine hall to another along the crane runways in the installation site. The placement of suction pipes in two tiers leads to an additional deepening of the HPP building.
When placing hydroelectric power plants in a narrow gorge, where it is difficult to carry out coastal spillways, spillways pass in the body of the dam, on its downstream side and on the floor of the building. Such an arrangement was made at the Toktogul HPP with a two-row arrangement of units in the HPP building (see Fig. 4.7). In this case, step-up transformers are placed indoors. With such an arrangement, the flow, passing through the spillway, is thrown from the HPP building by a toe-springboard to a considerable distance, and the energy is extinguished mainly due to the aeration of the flow.
A typical example of a dam building located behind a dam made of local materials with water supply through tunnels is the building of the Nurek HPP (see Fig. 4.9, 4.18). The HPP building has 9 units with a capacity of 300 MW each with a maximum head of 275 m. Water is supplied through three tunnels with a diameter of 9 m, each divided into 3 turbine conduits. The building is made with a lowered turbine hall with removable covers in the ceiling above the hydraulic units and the installation site. Overhead cranes are installed in the turbine hall and in the valve room for maintenance and repair of equipment, and a gantry crane is used for the installation and complete dismantling of the hydraulic unit and ball valve.
Buildings of diversion HPPs with radial-axial turbines practically do not differ from dam buildings. When installing bucket turbines, the design of the aggregate part of the HPP building changes. Instead of a turbine chamber, a pressure distribution pipeline is made in the form of a metal casing, on which turbine nozzles with flow control mechanisms are mounted, and water is discharged from the turbine through a non-pressure tray. Depending on the power of the hydraulic turbine and the number of nozzles, the axis of the hydraulic unit can be located vertically or horizontally. Due to the fact that the impeller of bucket turbines is located above the maximum level of the tailwater, when they are installed, the depth of the building is significantly reduced.
In the buildings of high-pressure diversion HPPs, with a large length or branching of pressure conduits, disk or ball valves are installed in front of the turbines, depending on the pressure and diameter (at pressures of more than 600 m, only ball valves), which allow shutting off the pipelines and stopping the hydraulic unit in an emergency in the event of a guide vane failure, as well as during normal operation and repair work.
Recently, instead of pre-turbine gates, built-in annular gates are used, which are placed between the stator columns and guide vanes, which makes it possible to reduce the dimensions of the building, the weight and cost of equipment.
Underground HPP buildings. In recent decades, the construction of underground hydroelectric power plants has been widely developed. Of these, the largest were built in Canada: Churchill Falls with a capacity of 5225 MW with a head of 320 m, Mika - 2610 MW with a head of 183 m. Ust-Khantayskaya - 441 MW in Russia, etc. In underground buildings, construction work does not depend on climatic conditions, which is important when building in northern regions with harsh winters or in the tropics with a long rainy season. Underground buildings are also used in cases where, due to unfavorable natural conditions in the gorge (steep landslide-prone slopes, high water level when a flood is passed), as well as a large deepening of the turbine wheel axis below the tailwater level, the construction of open buildings can lead to a violation of stability coastal slopes, to a sharp increase in the volume of work.
The disadvantages of underground buildings include: in the case of unfavorable engineering and geological conditions, a significant complication of underground work; complication of operating conditions due to the lengthening of technological communications, more complex schemes for power output; an increase in the cost of electricity for own needs, which is caused by the need for constant ventilation of the premises, their lighting, etc.
The dimensions and layout of underground HPP buildings depend primarily on the parameters and placement of hydropower, electrical and hydromechanical equipment. At large hydroelectric power plants, where the dimensions of the workings of the turbine halls reach large sizes (span up to 30 m or more), the main hydraulic power equipment is usually placed in the turbine hall, which is serviced by overhead cranes, and the pre-turbine gates are made in a separate room located at some distance from the turbine hall. With long discharge tunnels, the downstream repair gates and the mechanisms serving them for shutting off the exhaust pipes are also located in a separate room. With a large number of units, several discharge tunnels are arranged, most often non-pressure or pressure (with large fluctuations in the levels of the downstream) with a surge tank. For short tunnels that discharge water separately from each unit, downstream gates are installed in the exit portals of the tunnels.
One of the important factors determining the layout of buildings of underground hydroelectric power plants is the choice of the layout of the main step-up transformers: in a separate underground room (HPP Kariba in Zimbabwe, HPP Yali in Vietnam), in an expanded underground turbine hall (HPP Timet I and II in Australia), open on the surface of the earth at outdoor switchgear sites (Borisoglebskaya, Ingurskaya).
The open arrangement of transformers is mainly used for shallow placement of an underground building (at a depth of up to 200–300 m) and favorable topographic and geological conditions of the site. At the same time, current conductors from generators to transformers, which are of considerable length, are laid in special galleries and shafts with the implementation of special measures for heat removal due to the large heat dissipation by current conductors.
The transmission of electricity to the outdoor switchgear and indoor switchgear from the main transformers with their underground location is carried out at a voltage of 110-500 kV by oil-filled cables with special measures for heat removal, and recently also by gas-insulated busbars.
In underground buildings, installation sites are provided, which in most cases are a continuation of the turbine hall, located, as a rule, at its end and connected to the ground using transport tunnels and cargo shafts.
Fans and air conditioners are installed to remove heat and ventilate the underground spaces of the HPP building.
Turbine hall lining designs depend on engineering and geological conditions. In most turbine halls, a bearing vault of a circular shape is made with an increase in the thickness of the reinforced concrete lining at the heels. In sufficiently strong rocks, the walls are fastened with sprayed concrete, and in less strong ones, a continuous concrete or reinforced concrete cladding up to 0.5 m thick or more with reinforcement with anchors is arranged, in areas of weakened rocks - with strengthening cementation, and in some cases drainage measures are provided.
In the underground building of the Inguri hydroelectric power station with a length of 145.5 m, a span of 21.2 m and a cut height of 53.7 m, 5 hydraulic units were installed. Water is supplied to the units by turbine conduits, located in the plan at an angle to the longitudinal axis of the units, which made it possible to place pre-turbine gates within the turbine hall, practically without increasing its span (see Fig. 4.20). The water is diverted by a pressure tunnel.
Semi-underground HPP buildings. Under favorable engineering-geological and topographic conditions and large fluctuations in the level of the tailwater, semi-underground buildings can be built located in trench workings, and the top structures of the turbine halls can be arranged on the surface of the earth. Solutions for semi-underground buildings are possible with the placement of one or more units in separate shafts, above which the upper structure of the turbine hall is erected on the surface of the earth, as at the Dniester PSP.
The semi-underground building of the Vilyui hydroelectric power station with a capacity of 648 MW, made in a trench working 60 m deep, is completely located under the earth's surface (Fig. 4.21).
Buildings of small hydroelectric power stations. Small HPPs usually include hydroelectric power plants with a capacity of up to 10–30 MW. Along with the use of hydropower resources of large rivers at medium and large hydroelectric power stations, which in most cases require the creation of large reservoirs and operate in unified energy systems, small hydroelectric power stations have received wide development in the world. Such HPPs use the hydropower potential of small rivers, tributaries, waste channels and have an extremely limited impact on the environment. They can supply electricity to the power grid or work for a specific consumer, which is especially important for remote areas where there is no developed power transmission network.
Small HPPs, like large ones, are divided into HPPs with run-of-river and dam buildings and diversion HPPs.
At small HPPs, to simplify the structures in buildings with the installation of vertical hydraulic units, straight-axis conical suction pipes can be used, horizontal units, including capsule ones, as well as those with an inclined arrangement of the unit axis (see Fig. 4.12, diagrams IV, V, VII) are widely used.
On page 283 (photo) and in fig. 4.22 shows diversion HPPs - Tereblya-Rikskaya with a capacity of 27 MW with a head of 215 m and Egorlykskaya with a capacity of 30 MW with a head of 32 m.
The variety of options and the uniqueness of the technical solutions used in the construction of hydroelectric power plants is amazing. In fact, it is not easy to find two identical stations. But still there is their classification based on certain features - criteria.
Way to create pressure
Perhaps the most obvious criterion is way to create pressure:
- run-of-river hydroelectric power station (HPP);
- diversion hydroelectric power plant;
- pumped storage power plant (PSPP);
- tidal power plant (TPP).
There are characteristic differences between these four main types of hydroelectric power plants. river hydroelectric power station located on the river, blocking its flow with a dam to create pressure and a reservoir. Derivative HPP usually located on meandering mountain rivers, where branches of the river can be connected with a conduit to let part of the stream take a shorter path. In this case, the pressure is created by a natural difference in the terrain, and the reservoir may be completely absent. Hydrostorage power plant consists of two pools located at different levels. The basins are connected by conduits, through which water can flow into the lower basin from the upper one and be pumped back. tidal power plant located in a bay blocked by a dam to create a reservoir. Unlike pumped storage power plant The duty cycle of the PES depends on the tide phenomenon.
Head value
According to the magnitude of the pressure created by the hydraulic structure (HTS), hydroelectric power plants are divided into 4 groups:
- low-pressure - up to 20 m;
- medium pressure - from 20 to 70 m;
- high-pressure - from 70 to 200 m;
- ultra-high-pressure - from 200 m.
It should be noted that the classification head is relative and varies from one source to another.
Installed capacity
According to the installed capacity of the station - the sum of the rated capacities of the generating equipment installed on it. This classification has 3 groups:
- micro-hydro power plants - from 5 kW to 1 MW;
- small HPPs - from 1 kW to 10 MW;
- large hydroelectric power plants - over 10 MW.
Classification by installed capacity as well as the magnitude of the pressure, is not strict. The same station in different sources can be assigned to different groups.
Dam design
There are 4 main groups of hydroelectric dams:
- gravity;
- buttress;
- arched;
- arch-gravity.
gravity dam is a massive structure holding water in the reservoir due to its weight. buttress dam uses a slightly different mechanism - it compensates for its relatively small weight with the weight of water pressing on the inclined face of the dam from the upstream side. Arch dam , perhaps the most elegant, has the shape of an arch, resting on the banks with its base and a rounded part convex towards the reservoir. The retention of water at the arch dam occurs due to the redistribution of pressure from the front of the dam to the banks of the river.
Machine room location
More precisely, by the location of the engine room relative to the dam, not to be confused with layout! This classification is only relevant for run-of-river, diversion and tidal power plants.
- channel type;
- dam type.
At channel type the machine room is located directly in the body of the dam, dam type - erected separately from the body of the dam and is usually located immediately behind it.
Layout
The word "layout" in this context means the location of the engine room relative to the riverbed. Be careful when reading other literature on this topic, because the word layout has a broader meaning. The classification is valid only for run-of-river and diversion power plants.
- channel;
- floodplain;
- coastal.
At channel layout the machine room building is located in the riverbed, floodplain layout - in the floodplain of the river, and at coastal layout - on the bank of the river.
Overregulation
Namely, the degree of regulation of the flow of the river. The classification is only relevant for run-of-river and diversion hydropower plants.
- daily regulation (work cycle - one day);
- weekly regulation (work cycle - one week);
- annual regulation (operation cycle - one year);
- long-term regulation (work cycle - several years).
The classification reflects how large the hydroelectric reservoir is in relation to the volume of the river's annual flow.
All the above criteria are not mutually exclusive, that is, one and the same HPP can be a river type, high-pressure, medium power, run-of-river layout with a dam-type turbine room, an arch dam and a reservoir of annual regulation.
List of sources used
- Bryzgalov, V.I. Hydroelectric power plants: textbook. allowance / V.I. Bryzgalov, L.A. Gordon - Krasnoyarsk: CPI KSTU, 2002. - 541 p.
- Hydraulic structures: in 2 volumes / M.M. Grishin [i dr.]. - Moscow: Higher School, 1979. - V.2 - 336 p.
Definition
Peculiarities
Principle of operation
Hydropower in the world
The largest hydroelectric power plants in the world
Tucurui hydroelectric power station
Grand Coulee
Sayano-Shushenskaya hydroelectric power station
Krasnoyarsk HPP
Churchill Falls (HPP)
Hoover Dam
Aswan Dams
Hydroelectric power plants (HPP) Russian Federation
The history of the development of hydraulic engineering in Russian Federation
The largest hydroelectric power plants (HPP) Russian Federation
Bratsk HPP
Ust-Ilimskaya HPP
Boguchanskaya HPP
Volzhskaya HPP
Zhigulevskaya HPP
Bureyskaya HPP
Accidents and incidents at hydroelectric power plants
Vayont Dam
Novosibirsk hydroelectric power station
Accidents at the Sayano-Shushenskaya HPP
Small Hydro Power Plant (HPP)
Hydroelectric power station (HPP) - a power plant that uses the energy of a water stream as an energy source. Hydroelectric power plants (HPPs) are usually built on rivers by constructing dams and reservoirs.
For the efficient production of electricity at hydroelectric power plants, two main factors are necessary: a guaranteed supply of water all year round and the possible large slopes of the river, which favors hydro construction canyon-like topography.
Peculiarities
Initial cost electricity at Russian HPPs is more than two times lower than at thermal power plants.
Hydroelectric generators can be turned on and off quickly enough depending on energy consumption
Renewable energy source
Significantly less impact on the air environment than other types of power plants
HPP construction is usually more capital intensive
Often efficient HPPs are more remote from consumers
Reservoirs often cover large areas
Dams often change the nature of the fish economy, as they block the path to spawning grounds for migratory fish, but often favor the increase in fish stocks in the reservoir itself and the implementation of fish farming.
Principle work
Principle work HPS is quite simple. A chain of hydraulic structures provides the necessary pressure of water flowing to the blades of a hydraulic turbine, which drives generators that generate electricity.
The necessary pressure of water is formed through the construction of a dam, and as a result of the concentration of the river in a certain place, or by derivation - the natural flow of water. In some cases, both a dam and a derivation are used together to obtain the necessary water pressure.
All power equipment is located directly in the building of the hydroelectric power station (HPP). Depending on the purpose, it has its own specific division. In the engine room there are hydraulic units that directly convert the energy of the water current into electrical energy. There are also all kinds of additional equipment, control and monitoring devices for the operation of hydroelectric power stations, a transformer station, switchgear and much more.
Hydroelectric stations are divided depending on the generated power:
powerful - produce from 25 MW to 250 MW and more;
medium - up to 25 MW;
small hydroelectric power plants (HPP) - up to 5 MW.
The power of a hydroelectric power station directly depends on the pressure of the water, as well as on the efficiency of the generator used. Due to the fact that, according to natural laws, the water level is constantly changing, depending on the season, and also for a number of reasons, it is customary to take cyclic power as an expression for the power of a hydroelectric station. For example, there are annual, monthly, weekly or daily cycles of operation of a hydroelectric power station (HPP).
Hydroelectric power plants (HPPs) are also divided depending on the maximum use of water pressure:
high-pressure - more than 60 m;
medium pressure - from 25 m;
low-pressure - from 3 to 25 m.
Depending on the water pressure, various types of turbines are used in hydroelectric power plants (HPPs). For high-pressure - bucket and radial-axial turbines with metal volutes. At medium-pressure HPPs, rotary-blade and radial-axial turbines are installed, at low-pressure HPPs, rotary-blade turbines in reinforced concrete chambers are installed. The principle of operation of all types of turbines is similar - water under pressure (water pressure) enters the turbine blades, which begin to rotate. The mechanical energy is thus transferred to the hydroelectric generator, which generates electricity. Turbines differ in some technical characteristics, as well as chambers - iron or reinforced concrete, and are designed for different water pressures.
Hydroelectric stations are also divided depending on the principle of using natural resources, and, accordingly, the resulting water concentration. Here are the following HPPs:
run-of-river and near-dam HPPs. These are the most common types of hydroelectric power stations. The water pressure in them is created by installing a dam that completely blocks the river, or raises the water level in it to the required level. Such hydroelectric power plants (HPPs) are built on high-water lowland rivers, as well as on mountain rivers, in places where the riverbed is narrower, compressed.
dam hydroelectric power stations. Built with higher water pressure. In this case, the river is completely blocked by the dam, and the building of the hydroelectric power station itself is located behind the dam, in its lower part. Water, in this case, is supplied to the turbines through special pressure tunnels, and not directly, as in run-of-river hydroelectric power plants.
diversion hydroelectric power plants (HPP). Such power plants are built in places where the slope of the river is large. The necessary concentration of water in this type of HPP is created by derivation. Water is diverted from the river bed through special drainage systems. The latter are straightened, and their slope is much smaller than the average slope of the river. As a result, water is supplied directly to the power plant building. Diversion HPPs can be of various types non-pressure, or with pressure diversion. In the case of pressure diversion, the conduit is laid with a large longitudinal slope. In another case, at the beginning of the derivation, a higher dam is created on the river, and a reservoir is created - this scheme is also called mixed derivation, since both methods are used to create the necessary concentration of water.
hydro storage power plants. Such pumped storage power plants are capable of accumulating the generated electricity and putting it into operation at times of peak loads. The principle of operation of such power plants is as follows: at certain moments (times of non-peak load), the pumped storage units operate as pumps and pump water into specially equipped upper pools. When the need arises, water from them enters the pressure pipeline and, accordingly, drives additional turbines.
Hydroelectric stations, depending on their purpose, may also include additional structures, such as locks or ship lifts that facilitate navigation through the reservoir, fish passages, water intake structures used for irrigation, and much more.
The value of a hydroelectric station lies in the fact that for the production of electrical energy, they use renewable Natural resources. Due to the fact that there is no need for additional fuel for hydroelectric power plants, the final cost of electricity generated is much lower than when using other types of power plants.
Hydropower in the world
Canada is also the leader in generating hydropower per citizen. The most active hydro construction at the beginning of the 2000s is being carried out, for which hydropower is the main potential source of energy, up to half of the world's small hydroelectric power plants (HPPs) are located in the same country.
The largest hydroelectric power plants in the world
In 2005, hydropower provides the production of up to 63% of renewable and up to 19% of all electricity in the world, the installed hydropower capacity reaches 715 GW.
The leaders in the production of hydropower per citizen are Norway, Iceland and Canada. The most active hydraulic construction at the beginning of the 21st century is China, for which hydropower is the main potential source of energy, in the same country located up to half of the small hydroelectric power plants (HPP) of the world.
Itaipu
Itaipu is a large hydroelectric power station on the Parana River, 20 km from the city of Foz do Iguacu on the border of Brazil and Paraguay.
Design and preparation work began in 1971, the last two of the planned 18 generators were commissioned in 1991, and an additional two generators were commissioned in 2007.
The structure of HPP facilities:
Combined dam with a total length of 7,235 m, a width of 400 m and a height of 196 m;
Concrete spillway with a maximum flow of 62,200 m/s.
The station's capacity is 14,000 MW. The average annual output is 69.5 billion kWh, after the completion of construction in 2007 - 90-95 billion kWh per year.
The power equipment of the station consists of 20 hydraulic units with a capacity of 700 MW each, due to the excess of the calculated pressure, the power available for generators reaches 750 MW for more than half of the operating time.
The dam of the hydroelectric power plant (HPP) formed a relatively small - in relation to capacity - reservoir 170 km long, 7 to 12 km wide, 1,350 km² in area and 29 km² in volume.
For its construction, the government resettled about 10 thousand families living on the coast of Parana, many of whom joined the Landless Movement.
Price The construction of Itaipu was originally estimated by experts at $4.4 billion, but due to the ineffective policy of successive dictatorial regimes, it actually amounted to $15.3 billion.
Guri
Guri is a large hydroelectric power station in the Republic of Venezuela in the Bolivar department on the Caroni River, 100 km before it flows into the Orinoco.
The official name is the hydroelectric power plant (HPP) named after Simon Bolivar (in 1978-2000 - named after Raul Leoni).
The third station in the world in terms of power after the Chinese "Sanxia" and the Brazilian "Itaipu".
The construction of the HPP began in 1963, the first stage was completed in 1978, the second in 1986.
The structure of HPP facilities:
a dam with a total length of 1300 m and a height of 162 m;
two machine rooms with 10 hydraulic units in each;
concrete spillway with a maximum capacity of 25,500 m3/s.
The power of the station is 10,300 MW. In the first turbine hall, 10 units with a capacity of 400 MW each are installed, in the second - 10 units with a capacity of 630 MW each. The maximum annual output is 46 billion kWh. The pressure structures of the HPP (total length reaches 7,000 m) form a large Guri reservoir with a length of 175 km, a width of 48 km, an area of up to 4,250 km² and a total volume of 138 km². The water edge of the reservoir is located at an altitude of 272 m above sea level.
Reconstruction has been underway since 2000: until 2007, 5 turbines and the main components of the second turbine hall were replaced, since 2007, four units in the first hall have been replaced.
The walls of the second engine room are decorated by the Venezuelan artist Carlos Cruz-Diez.
Tukurui HPP
Tukurui HPP (Guarani, Portuguese: Tucurun, Usina Hidrelétrica de Tucurun) is a hydroelectric power plant (HPP) on the Tocantins River, located in the county of Tukurui, Tocantins,.
The hydroelectric power station is named after the city of "Tukurui", which existed near the construction site. Now a city with the same name exists downstream from the dam. The installed capacity of the hydroelectric power plant (HPP) is 8,370 MW, with a total of 24 generators.
In 1970, was formed from the Brazilian companies ENGEVIX and THEMAG, which won the international for the development and implementation of the project. The work began in 1976 and was completed in 1984. The length of the dam was 11 km, the height was 76 m.
The hydroelectric power plant featured in the 1985 film The Emerald Forest.
Grand Coulee
Grand Coulee is a hydroelectric power plant (HPP) located in North America, the largest in the United States and the fifth largest in the world.
The construction of the hydroelectric power station was completed in June 1942. The 11.9 km3 reservoir was built to generate electricity and irrigate desert areas on the northwest coast. The waters of the reservoir irrigate about 2000 km² of agricultural land.
The concrete gravity dam of the hydroelectric power plant, in the body of which 9.16 million m3 of concrete was laid, has a length of 1592 m and a height of 168 m. The width of the spillway part of the dam is 503 m. generate 20 TWh of electricity annually.
Sayano-Shushenskaya HPP
Sayano-Shushenskaya hydroelectric power station named after P. S. Neporozhny is the most powerful power plant in the Russian Federation, the sixth largest hydroelectric power plant (HPP) in the world. Located on the Yenisei River, in the village of Cheryomushki (Khakassia), near Sayanogorsk.
It is the most powerful power plant in the Russian Federation. Before the 2009 accident, it produced 15 percent of the energy generated by Russian hydroelectric power plants (HPPs) and 2 percent total amount of electricity. The structure of HPP facilities:
concrete arch-gravity dam 245 m high, 1,066 m long, 110 m wide at the base, 25 m wide along the crest. .6 m and the right-bank blind part 298.5 m long.
hydroelectric dam building
coastal spillway under construction.
HPP capacity - 6,400 MW (together with the Main hydroelectric complex - 6,721 MW), the average annual output is 24.5 billion kWh. In 2006, due to a major summer flood, the power plant generated 26.8 billion kWh of electricity.
The HPP building housed 10 radial-axial hydraulic units with a capacity of 640 MW each, operating at a design head of 194 m. The maximum static head on the dam is 220 m. it is much smaller.
The capacity of the dam's spillway is 13600 m/s, the maximum recorded inflow to the site is 24400 m/s, the spillway under construction should increase the largest discharged flow by 8000 m/s.
Downstream of the Sayano-Shushenskaya HPP is its counter-regulator, the Mainskaya HPP with a capacity of 321 MW, which is organizationally part of the Sayano-Shushenskaya hydropower complex.
The HPP dam forms a large Sayano-Shushenskoye reservoir with a total volume of 31.34 cubic meters. km (useful volume - 15.34 cubic km) and an area of 621 sq. km. km. The water of the reservoir is of high quality, which made it possible to organize fish farms specializing in trout farming in the downstream of the hydroelectric power station. During the creation of the reservoir, 35.6 thousand hectares of agricultural land were flooded and 2717 buildings were moved. The Sayano-Shushensky Biosphere Reserve is located in the area of the reservoir.
The Sayano-Shushenskaya HPP was designed by the Lengydroproekt Institute.
Krasnoyarsk HPP
The Krasnoyarsk hydroelectric power station is on the Yenisei River, forty kilometers from Krasnoyarsk, near the city of Divnogorsk in the Krasnoyarsk Territory. The second largest HPP in the Russian Federation. Included in the Yenisei HPP cascade.
The Krasnoyarsk HPP was designed by the Lengydroproekt Institute.
The construction of the hydroelectric power station began in 1956 and ended in 1972. The first block of the Krasnoyarsk hydroelectric power station was launched on November 3, 1967.
The structure of HPP facilities:
gravity concrete dam with a length of 1,065 m and a height of 124 m, consists of a left-bank blind dam 187.5 m long, a weir - 225 m, a blind channel dam - 60 m, a station dam - 360 m and a right-bank blind dam - 232.5 m. the body of the dam was laid 5.7 million m3 of concrete.
430 m long hydroelectric power plant near the dam.
Installations for the reception and distribution of electricity - 220 kV and 500 kV.
Ship lift.
HPP capacity - 6000 MW. The average annual electricity generation is 20.4 billion kWh. 12 radial-axial hydraulic units with a capacity of 500 MW each, operating at a design head of 93 m, are installed in the HPP building. The only ship lift in the Russian Federation has been built for the passage of ships.
The hydroelectric dam forms a large Krasnoyarsk reservoir. The area of the reservoir is about 2000 km², the total and useful volumes are 73.3 and 30.4 km², respectively. The reservoir flooded 120 thousand hectares of agricultural land, during the construction 13,750 buildings were moved.
Churchill Falls (HPP)
Churchill Falls is a diversion hydroelectric power station on the Churchill River in the Canadian province of Newfoundland and Labrador, to become part of the projected cascade of hydroelectric power stations on the river. A hydroelectric power station (HPP) was built on the site of the 75 m high Churchill Falls, which, after the diversion of the river in 1970, was drained, that is, it does not exist as a waterfall for most of the year. The river, waterfall and hydroelectric power station are named after British Prime Minister W. Churchill.
As of 2009, the Churchill Falls HPP has the second largest underground power plant in the world after the Robert-Bourassa HPP in northern Quebec, is the first hydroelectric power plant (HPP) in North America in terms of average annual output (35 TWh) and the second in Canada by installed capacity (5,428 MW).
The construction of a hydroelectric power station (HPP) was started on July 17, 1967 after several years of planning, completed on December 6, 1971. The reservoir - with a total area of 6,988 km2 and a volume of 28 km3 - was formed not by one dam, but by 88 diversion dams with a total length of more than 64 km, during the construction of which 20 million m3 of soil was used. The longest of the dams is 6.1 km long. This scheme made it possible to increase the catchment area from 60,000 km2 to 71,700 km2 and bring the average annual flow in the area of the hydroelectric complex to 52 km3 (1,651 m/s).
The hydroelectric power station (HPP) is made according to the diversion principle with the diversion of the river in the area of the waterfall. It is supplied with a spillway with a throughput of 1,390 m3/sec. Mash M3 The main hall of the HPP, which is underground according to the project, is made in a rocky working at a depth of 310 m. The dimensions of the turbine hall are 296 m long, 25 m wide and 47 m high. In total, it has 11 hydroelectric units with a total capacity of 5,428 MW. Each of the radial-axial turbines, operating at a design head of 312.4 m, has a mass of 73 tons and an operating frequency of 200 rpm. Generator power M3 ditch 493.5 MW. The water conduits of the units are made in the form of supply tunnels with a length of 427 m and a diameter of 6.1 m and spillways to generators with a height of 263 m and a diameter of 2.13 m.
The station is owned by Churchill Falls (Labrador) corporation Ltd, a controlling stake (65.8%) of which is owned by Nalcor, 34.2% by Hydro-Québec. There is a plant development project that includes the construction of new dams and additional hydroelectric power plants (HPPs), which should provide an increase in the catchment area and bring the total installed capacity to 9,252 MW.
Hoover Dam
Hoover Dam, Hoover Dam, Hoover Dam (Eng. Hoover Dam, also known as Boulder Dam) is a unique hydraulic structure in USA, a concrete dam with a height of 221 m and a hydroelectric power plant (HPP), built in the lower reaches of the Colorado River. Located in the Black Canyon, on the border of the states of Arizona and Nevada, 48 km southeast of Las Vegas; forms a lake (reservoir) Mead. Named after the 31st President of the United States Herbert Hoover, 31st President USA who played an important role in its construction. Construction of the dam began in 1931 and ended in 1936, two years ahead of schedule.
The dam is administered by the US Bureau of Reclamation, a division of the US Department of the Interior. In 1981, the dam was listed on the US National Register of Historic Places. The Hoover Dam is one of the most famous attractions in the Las Vegas area.
A hydroelectric power plant (Hydro power plant, HPP) is
Introduction
People learned a long time ago to use the energy of water in order to rotate the impellers of mills, machine tools, and sawmills. But gradually the share of hydropower in the total amount of energy used by man has decreased. This is due to the limited ability to transfer water energy over long distances. With the advent of the electric turbine driven by water, hydropower has a new perspective.
Some of the first hydroelectric installations with a capacity of only a few hundred watts were built in 1876-1881 in Stangasse and Laufen (Germany) and in Grayside (England). The development of hydroelectric power plants and their industrial use is closely related to the problem of transmitting electricity over a distance. The construction of a power transmission line (170 km) from the Laufen hydroelectric power station to Frankfurt am Main (Germany) to supply electricity. The International Electrotechnical Exhibition (1891) opened up wide opportunities for the development of hydroelectric power stations. In 1892, a hydroelectric power station built on a waterfall in Bulach (Switzerland) provided industrial current, almost simultaneously in 1893 hydroelectric power stations were built in Gelschen (Sweden), on the Isar River (Germany) and in California (USA). In 1896, the Niagara Hydroelectric Power Station (USA) of direct current came into operation; in 1898 it gave current to the Reinfeld hydroelectric power station (Germany), and in 1901 the hydroelectric generators of the Jonat hydroelectric power station (France) began to be loaded.
Convincing information about the world's first hydroelectric power station can be considered information about the first hydroelectric power station in Croatia in the town of Sibenik (1885). An alternating current voltage of 230 kW was used for urban lighting.
The most reliable is that the first hydroelectric power station in Russia was the Berezovskaya (Zyryanovskaya) hydroelectric power station, built in Rudny Altai on the Berezovka River (a tributary of the Bukhtarma River) in 1892. It was a four-turbine with a total capacity of 200 kW. The resulting energy illuminated the production facilities, ensured the operation of the telephone exchange, and fed electric pumps for pumping water from mine shafts.
The Nygrinskaya HPP, which appeared in the Irkutsk province on the Nygri River (a tributary of the Vacha River) in 1896, also claims to be the first. The power equipment of the station consisted of two turbines with a common horizontal shaft, which rotated three 100 kW dynamos. The primary voltage was converted by four three-phase current transformers up to 10 kV and transmitted via two high-voltage lines to the neighboring Negadanny and Ivanovsky mines. At the mines, the voltage was transformed to 220 V. Thanks to the electricity from the Nygrinskaya HPP, electric lifts were installed in the mines. In addition, the mine was electrified railway, which served for the export of waste rock, which became the first electrified railway in Russia.
In 2012, hydropower provides the production of up to 21% of all electricity in the world, the installed power capacity of hydroelectric power plants (HPPs) reaches 715 GW. The leaders in hydropower generation in absolute terms are: China, Canada, Brazil; and per capita - Norway, Iceland and Canada. The world's largest hydroelectric power plants are:
Three Gorges (China, Yangtze River) - 22.4 GW,
Itaipu (Brazil, Parana River) - 14 GW,
Guri (Venezuela, Caroni River) 10.3 GW,
Tucurui (Brazil, Tocantins River) - 8.3 GW,
Grand Coulee (USA, Columbia River) - 6.8 GW,
Sayano-Shushenskaya (Russia, the Yenisei River) 6.4 GW,
Krasnoyarsk (Russia, the Yenisei River) 6 GW,
Robert-Bourassa (Canada, La Grande River) 5.6 GW,
Churchill Falls (Canada, Churchill River) - 5.4 GW,
As of 2011, there are 15 operating, under construction and frozen hydraulic power plants in Russia with over 1000 MW and more than a hundred hydroelectric power plants of smaller capacity.
At the same time, in terms of the economic potential of hydropower resources, Russia ranks second in the world (about 852 billion kWh) after China, however, in terms of the degree of their development - 20% - it is inferior to almost all developed countries and many developing countries. The degree of wear of the equipment of most Russian hydropower plants exceeds 40%, and for some HPPs this figure reaches 70%, which is associated with a systemic problem for the entire hydropower industry and its chronic underfunding.
1. Main types of HPPs
Run-of-river and dam hydropower plants
Dam; 2 - shutters; 3 - maximum headwater level; 4 - minimum headwater level; 5 - hydraulic lift; 6 - trash grate; 7 hydro generator; 8 - hydraulic turbine; 9 - the minimum level of the downstream; 10 - maximum flood level
Dam HPPs
Built with higher water pressure. In this case, the river is completely blocked by the dam, and the building of the hydroelectric power station itself is located behind the dam, in its lower part. Water, in this case, is supplied to the turbines through special pressure tunnels, and not directly, as in run-of-river hydroelectric power plants.
Dam; 2 - conduit; 3 - site of high voltage electrical equipment; 4 - the building of the turbine hall of the HPP.
Derivative hydroelectric power plants:
Derivative hydroelectric power plants. Such power plants are built in places where the slope of the river is large. The necessary concentration of water in this type of HPP is created by derivation. Water is diverted from the river bed through special drainage systems. The latter are straightened, and their slope is much smaller than the average slope of the river. As a result, water is supplied directly to the power plant building. Derivative HPPs can be of different types - non-pressure or with pressure derivation. In the case of pressure diversion, the conduit is laid with a large longitudinal slope. In another case, at the beginning of the derivation, a higher dam is created on the river, and a reservoir is created - this scheme is also called mixed derivation, since both methods of creating the necessary water concentration are used.
Scheme of a diversion hydroelectric station: 1 - dam; 2 water lift; 3 - sump; 4 - derivation channel; 5 - pool of daily regulation; 6 - pressure basin; 7 - turbine conduit; 8 - switchgear; 9 - HPP building; 10 - spillway; 11 - access roads
Hydrostorage power plants:
Such pumped storage power plants are capable of accumulating the generated electricity and putting it into operation at times of peak loads. The principle of operation of such power plants is as follows: during certain periods (not peak load), pumped storage units operate as pumps from external energy sources and pump water into specially equipped upper pools. When the need arises, water from them enters the pressure pipeline and drives the turbines.
Tidal hydropower plants (TPPs):
A special type of hydroelectric power plant that uses the energy of the tides, but in fact the kinetic energy of the rotation of the Earth. Tidal power plants use the difference in water levels (water level fluctuations near the coast can reach 12 meters), which is formed during high and low tide. To do this, the coastal basin is separated by a low dam, which retains tidal water at low tide. Then the water is released, and it rotates the hydraulic turbines that can operate both in generator mode and in pump mode (for pumping water into the reservoir for subsequent operation in the absence of tides).
. The principle of operation of the hydroelectric power station. The main structures and equipment of hydroelectric power plants
A hydroelectric power plant is a complex of structures and equipment by means of which the energy of the flow of water is converted into electrical energy.
Hydroelectric power stations are an integral part of a hydroelectric complex - a complex of hydraulic structures designed to use water resources in the interests of the national economy: generating electricity, irrigation, water supply, improving navigation conditions, flood protection, fish farming, etc.
The power of the hydraulic flow depends on the flow and pressure. The flow rate of water in the river varies along its length with a change in the cross section of the channel and the hydraulic slope. To concentrate the power and concentrate the pressure of the river in any one place, hydraulic structures are erected: a dam, a diversion canal.
Spillway facilities bypass water from the upstream to the downstream in order to avoid exceeding the maximum design water level during the flood period, dump ice, sludge, etc.
If the river is navigable, then locks (ship lifts) with approach channels are adjacent to the dam for the passage of ships and rafts through the hydroelectric complex, transshipment of goods and transfer of passengers from water to land transport, etc.
To ensure the selection and supply of water to non-energy consumers, the hydroelectric complex includes water intake facilities and pumping stations.
Fisheries facilities are fish passages and fish lifts for passing valuable fish species through the hydroelectric complex to permanent spawning grounds, fish protection facilities and facilities for artificial fish breeding. Sometimes fish are passed through locks in the process of locking ships.
To connect the objects of the hydroelectric complex with each other, to connect them with the network of state roads and railways, as well as to pass these roads through the structures of the hydroelectric complex, transport facilities are built: bridges, roads, etc.
To generate electricity and distribute it to consumers, the hydroelectric complex includes various energy facilities. These include: water intakes and conduits that bring water from the upstream to the turbines and divert water to the downstream; the building of hydroelectric power plants with hydro turbines, hydro generators and transformers; auxiliary mechanical and hoisting and transport equipment; Remote Control; open switchgears designed to receive and distribute energy.
The principle of operation of a hydroelectric power station is as follows: the dam forms a reservoir, providing a constant pressure of water. Water enters the water intake and, passing through the pressure conduit, rotates the hydro turbine, which drives the hydro generator. The output voltage of hydro generators is increased by transformers for transmission to distribution substations and then to consumers.
The pressure is created by the concentration of the fall of the river in the used section by a dam, or by a derivation, or by a dam and a derivation together. Derivation in hydraulic engineering is a set of structures that drain water from a river, reservoir or other body of water, transport it to the station node of a hydroelectric power station, a pumping station, and also drain water from them. Distinguish derivation pressureless and pressure. Pressure diversion - a pipeline, a pressure tunnel, is used when fluctuations in the water level at the place of its intake or discharge are significant. With small level fluctuations, both pressure and non-pressure derivation can be used. The type of derivation is selected taking into account the natural conditions of the area on the basis of a technical and economic calculation. The length of modern diversion conduits reaches several tens of kilometers, the throughput capacity is more than 2000 m 3 /sec. The main power equipment is located in the HPP building: in the engine room of the power plant - hydraulic units, auxiliary equipment, automatic control and monitoring devices; in the central control post, the operator-dispatcher console or the automatic operator of the hydroelectric power station. The step-up transformer substation is located both inside the HPP building, and in separate buildings or in open areas. Distribution devices are often located in an open area. The building can be divided into sections with one or more units and auxiliary equipment, separated from adjacent parts of the building. An assembly site is created at the power plant building or inside it for the assembly and repair of various equipment and for auxiliary maintenance operations. According to the installed capacity, powerful (over 250 MW), medium (up to 25 MW) and small (up to 5 MW) are distinguished. The power of the HPP depends on the head (the difference between the levels of the upper and lower water flow Q (m 3 / s)), used in hydro turbines, and the efficiency of the hydro unit.
According to the maximum used head, HPPs are divided into high-pressure (more than 60 m), medium-pressure (from 25 to 60 m) and low-pressure (from 3 to 25 m). On flat rivers, heads rarely exceed 100 m; in mountainous conditions, heads up to 300 m or more can be created by means of a dam, and up to 1,500 m with the help of derivation.
One of the most important components of hydroelectric power plants are hydroelectric generators and hydroturbines.
Hydroturbines.
The hydraulic turbine converts the energy of water flowing under pressure into mechanical energy of shaft rotation.
According to the principle of operation, hydroturbines are divided into jet (pressure jet) and active (free jet). Water enters the impeller either through nozzles (in active hydraulic turbines) or through a guide vane (in jet hydraulic turbines).
The most common type of active hydro turbine is bucket turbine. Pelton turbines are structurally very different from the most common jet turbines (radial-axial, rotary-blade), in which the impeller is in the water stream. In bucket turbines, water is supplied through nozzles tangentially to a circle passing through the middle of the bucket. Water, passing through the nozzle, forms a jet flying at high speed and hitting the turbine blade, after which the wheel turns, doing work. After the deflection of one blade, another one is substituted under the jet. The process of using the jet energy takes place at atmospheric pressure, and energy production is carried out only at the expense of the kinetic energy of water. Turbine blades are biconcave with a sharp blade in the middle; the task of the blade is to split the stream of water in order to better use the energy. Pelton hydraulic turbines are used at heads over 200 meters (most often 300-500 meters or more), at flow rates up to 100 m³/s. The power of the largest bucket turbines can reach 200-250 MW or more. At heads up to 700 meters, bucket turbines compete with radial-axial ones, at high heads their use has no alternative. As a rule, HPPs with bucket turbines are built according to the diversion scheme, since it is problematic to obtain such significant pressures using a dam. The advantages of bucket turbines are the possibility of using very high heads, as well as low water flow rates. The disadvantages of the turbine are inefficiency at low pressures, the inability to use it as a pump, and high requirements for the quality of the supplied water.
Radial-axial turbine (Francis turbine) - jet turbine. In the impeller of turbines of this type, the flow first moves radially (from the periphery to the center), and then in the axial direction (to the outlet). They are used at heads up to 600 m. Power up to 640 MW.
The main advantage of turbines of this type is the highest optimum efficiency of all existing types. The disadvantage is a less flat operating characteristic than that of a Kaplan turbine.
Kaplan turbine- a jet turbine, the blades of which can rotate around their axis at the same time, due to which its power is regulated. Also, the power can be adjusted using the blades of the guide device. The blades of a hydraulic turbine can be located both perpendicular to its axis and at an angle. The flow of water in a rotary-blade turbine moves along its axis. The axis of the turbine can be located both vertically and horizontally. With a vertical axis, the flow, before entering the working chamber of the turbine, is twisted in a spiral chamber, and then straightened with a fairing. This is necessary for a uniform supply of water to the turbine blades, and therefore, to reduce its wear. It is used mainly in medium-pressure hydroelectric power plants.
Diagonal turbine- jet turbine used at medium and high pressures. The diagonal turbine is a rotary-blade turbine, the blades of which are located at an acute (45-60°) angle to the turbine rotation axis. This arrangement of the blades allows you to increase their number (up to 10-12 pieces) and use the turbine at higher pressures. Diagonal turbines are used at heads from 30 to 200 meters, competing at low heads with classic Kaplan turbines, and at high heads with radial-axial turbines. Compared to the latter, diagonal turbines have a slightly higher efficiency, but are structurally more complex and more prone to wear.
hydro generator- an electric machine designed to generate electricity at a hydroelectric power station. Typically, a hydro generator is a synchronous salient-pole electric machine of a vertical design, driven by a hydro turbine, although there are also horizontal hydro generators (including capsule hydro generators).
Hydro generators have a relatively low speed (up to 500 rpm) and a fairly large diameter (up to 20 m), which primarily determines the vertical design of most hydro generators, since with a horizontal design it becomes impossible to provide the necessary mechanical strength and rigidity of their structural elements.
Pumped storage power plants use reversible hydro generators (hydro generators-motors), which can both generate electrical energy and consume it. They differ from conventional hydro generators in the special design of the thrust bearing, which allows the rotor to rotate in both directions.
Hydrogenerators for hydroelectric power plants are specially designed according to the speed and power of the hydroturbines for which they are intended. Hydrogenerators for large unit power are usually installed vertically on thrust bearings with appropriate guide bearings. They are usually three-phase and are designed for standard frequency. The air cooling system is closed, with air-to-water heat exchangers.
3. Advantages and disadvantages of HPP
The main advantages of hydropower are obvious. Of course, the main advantage of hydro resources is their renewability: the supply of water is practically inexhaustible. At the same time, hydro resources are significantly ahead of other types of renewable energy sources in development and are able to provide energy to large cities and entire regions.
In addition, it is quite easy to use this source of energy, as evidenced by the long history of hydropower. For example, hydroelectric generators can be turned on or off depending on the demand.
At the same time, the issue of the impact of hydropower on the environment is quite controversial. On the one hand, the operation of hydroelectric power plants does not lead to pollution of nature with harmful substances, in contrast to CO 2 emissions produced by thermal power plants and possible accidents at nuclear power plants, which can incur global catastrophic consequences.
But at the same time, the formation of reservoirs requires the flooding of large areas, often fertile, and this causes negative changes in nature. Dams often block the way for fish to spawn, disrupt the natural flow of rivers, lead to the development of stagnant processes, reduce the ability to "self-purify", and therefore dramatically change the quality of water.
The cost of energy produced at hydroelectric power plants is much lower than at nuclear and thermal power plants, and they are able to quickly reach the operating power output mode after switching on, but their construction is more expensive.
Modern technologies for the production of hydroelectric power allow you to get a fairly high efficiency. Sometimes it is twice as high as that of conventional thermal power plants. In many ways, this efficiency is ensured by the features of the equipment of hydroelectric power plants. It is very reliable and easy to use.
In addition, all the equipment used has another important advantage. This is a long service life, which is explained by the absence of heat in the production process. And really often you don’t need to change equipment, breakdowns happen extremely rarely. The minimum service life of a hydroelectric power station is about fifty years. And in the expanses of the former Soviet Union, stations built in the twenties or thirties of the last century are successfully operating. Hydroelectric power plants are managed through a central hub, and as a result, in most cases, there are few people working there.
Conclusion
hydroelectric turbine cost price energy
The potential for hydropower can be determined by summing up all the river flows that exist on the planet. Calculations showed that the world potential is equal to fifty billion kilowatts per year. But this very impressive figure is only a quarter of the amount of precipitation that falls annually throughout the world.
Taking into account the conditions of each specific region and the state of the world's rivers, the actual potential of water resources is from two to three billion kilowatts. These figures correspond to an annual power generation of 10,000 to 20,000 billion kilowatts per hour.
To understand the potential of hydropower, expressed by these figures, it is necessary to compare the obtained data with the indicators of oil thermal power plants. To generate this amount of electricity, oil-fired stations would require about forty million barrels of oil every day.
Without a doubt, hydropower in the future should not have a negative impact on the environment or reduce it to a minimum. At the same time, it is necessary to achieve maximum use of hydro resources.
This is understood by many specialists, and therefore the problem of preserving the natural environment during active hydraulic engineering construction is more relevant than ever. At present, an accurate forecast of the possible consequences of the construction of hydrotechnical facilities is especially important. It should answer many questions regarding the possibility of mitigating and overcoming undesirable environmental situations that may arise during construction. In addition, a comparative assessment of the environmental efficiency of future hydroelectric facilities is required. True, the implementation of such plans is still far away, since today the development of methods for determining the environmental energy potential is not being carried out.
List of sources
1. Neporozhny P.S., Obrezkov V.I.; "Introduction to the specialty: hydroelectric power." ed. Moscow, 1982
Drobnis V.F. "Hydraulics and hydraulic machines", ed. Moscow, 1987
hydroelectric power plant
Hydroelectric power plant (HPP)- a power plant that uses the energy of a water stream as an energy source. Hydroelectric power plants are usually built on rivers by constructing dams and reservoirs.
For the efficient production of electricity at hydroelectric power plants, two main factors are necessary: a guaranteed supply of water all year round and the possible large slopes of the river, favoring hydro construction canyon-like topography.
Peculiarities
Principle of operation
The principle of operation of a hydroelectric power station is quite simple. A chain of hydraulic structures provides the necessary pressure of water flowing to the blades of a hydraulic turbine, which drives generators that generate electricity.
The largest hydroelectric power plants in the world
| Name | Power, GW |
Average annual generation, billion kWh |
Owner | Geography |
|---|---|---|---|---|
| three gorges | 22,40 | 100,00 | R. Yangtze, Sandouping, China | |
| Itaipu | 14,00 | 100,00 | Itaipu Binacional | R. Parana , Foz do Iguacu , Brazil / Paraguay |
| Guri | 10,30 | 40,00 | R. Caroni, Venezuela | |
| Churchill Falls | 5,43 | 35,00 | Newfoundland and Labrador Hydro | R. Churchill, Canada |
| Tucurui | 8,30 | 21,00 | Eletrobras | R. Tocantins, Brazil |
Hydroelectric power plants in Russia
As of 2009, Russia has 15 hydroelectric power plants over 1000 MW (operating, being completed or under construction), and more than a hundred hydroelectric power plants of smaller capacity.
The largest hydroelectric power plants in Russia
| Name | Power, GW |
Average annual generation, billion kWh |
Owner | Geography |
|---|---|---|---|---|
| Sayano-Shushenskaya HPP | 2,56 (6,40) | 23,50 | JSC RusHydro | R. Yenisei, Sayanogorsk |
| Krasnoyarsk HPP | 6,00 | 20,40 | OJSC Krasnoyarskaya HPP | R. Yenisei, Divnogorsk |
| Bratsk HPP | 4,52 | 22,60 | OAO Irkutskenergo, RFBR | R. Angara, Bratsk |
| Ust-Ilimskaya HPP | 3,84 | 21,70 | OAO Irkutskenergo, RFBR | R. Angara, Ust-Ilimsk |
| Boguchanskaya HPP | 3,00 | 17,60 | OAO Boguchanskaya HPP, OAO RusHydro | R. Angara, Kodinsk |
| Volzhskaya HPP | 2,58 | 12,30 | JSC RusHydro | R. Volga, Volzhsky |
| Zhigulevskaya HPP | 2,32 | 10,50 | JSC RusHydro | R. Volga, Zhigulevsk |
| Bureyskaya HPP | 2,01 | 7,10 | JSC RusHydro | R. Bureya, pos. Talakan |
| Cheboksary HPP | 1,40 (0,8) | 3,31 (2,2) | JSC RusHydro | R. Volga, Novocheboksarsk |
| Saratov HPP | 1,36 | 5,7 | JSC RusHydro | R. Volga, Balakovo |
| Zeya HPP | 1,33 | 4,91 | JSC RusHydro | R. Zeya, Zeya |
| Nizhnekamsk HPP | 1,25 (0,45) | 2,67 (1,8) | OJSC "Generation Company", OJSC "Tatenergo" | R. Kama, Naberezhnye Chelny |
| Zagorsk PSP | 1,20 | 1,95 | JSC RusHydro | R. Kunya, pos. Bogorodskoe |
| Votkinskaya HPP | 1,02 | 2,60 | JSC RusHydro | R. Kama, Tchaikovsky |
| Chirkeyskaya HPP | 1,00 | 2,47 | JSC RusHydro | R. Sulak, Dubki village |
Notes:
Other hydroelectric power plants in Russia
Background of the development of hydraulic engineering in Russia
In the Soviet period of energy development, emphasis was placed on the special role of the unified national economic plan for the electrification of the country - GOELRO, which was approved on December 22, 1920. This day was declared a professional holiday in the USSR - Power Engineer's Day. The chapter of the plan devoted to hydropower was called "Electrification and Water Energy". It pointed out that hydroelectric power plants can be economically beneficial, mainly in the case of complex use: for generating electricity, improving navigation conditions or land reclamation. It was assumed that within 10-15 years it would be possible to build hydroelectric power stations in the country with a total capacity of 21,254 thousand horsepower (about 15 million kW), including in the European part of Russia - with a capacity of 7394, in Turkestan - 3020, in Siberia - 10,840 thousand hp Construction of HPPs with a capacity of 950,000 kW was planned for the next 10 years; however, in the future, it was planned to build ten HPPs with a total working capacity of the first stages of 535,000 kW.
Although already a year before, in 1919, the Council of Labor and Defense recognized the construction of the Volkhov and Svir hydroelectric stations as objects of defense importance. In the same year, preparations began for the construction of the Volkhovskaya HPP, the first of the hydroelectric power plants built according to the GOELRO plan.
However, even before the construction of the Volkhovskaya HPP, Russia had a fairly rich experience in industrial hydraulic construction, mainly by private companies and concessions. Information about these HPPs built in Russia during the last decade of the 19th century and the first 20 years of the 20th century is quite scattered, contradictory and requires special historical research.
The most reliable is that the first hydroelectric power station in Russia was the Berezovskaya (Zyryanovskaya) hydroelectric power station, built in Rudny Altai on the Berezovka River (a tributary of the Bukhtarma River) in 1892. It was a four-turbine with a total capacity of 200 kW and was intended to provide electricity for mine drainage from the Zyryanovsky mine.
The Nygrinskaya HPP, which appeared in the Irkutsk province on the Nygri River (a tributary of the Vacha River) in 1896, also claims to be the first. The power equipment of the station consisted of two turbines with a common horizontal shaft, which rotated three 100 kW dynamos. The primary voltage was converted by four three-phase current transformers up to 10 kV and transmitted via two high-voltage lines to neighboring mines. These were the first high-voltage power lines in Russia. One line (9 km long) was laid through the goltsy to the Negadanny mine, the other (14 km) - up the Nygri valley to the mouth of the Sukhoi Log spring, where the Ivanovsky mine operated in those years. At the mines, the voltage was transformed to 220 V. Thanks to the electricity from the Nygrinskaya HPP, electric lifts were installed in the mines. In addition, the mining railway was electrified, which served for the export of waste rock, which became the first electrified railway in Russia.
Advantages
- use of renewable energy.
- very cheap electricity.
- work is not accompanied by harmful emissions into the atmosphere.
- quick (relative to CHP/TPP) access to the operating power output mode after the station is turned on.
Flaws
- flooding of arable land
- construction is carried out only where there are large reserves of water energy
- on mountain rivers are dangerous due to the high seismicity of the areas
- reduced and unregulated water releases from reservoirs for 10-15 days (up to their absence), lead to the restructuring of unique floodplain ecosystems throughout the riverbed, as a result, river pollution, reduction in food chains, a decrease in the number of fish, the elimination of invertebrate aquatic animals, an increase aggressiveness of midge components (midges) due to malnutrition in the larval stages, the disappearance of nesting sites for many species of migratory birds, insufficient moisture in the floodplain soil, negative plant successions (depletion of phytomass), and a reduction in the flow of nutrients to the oceans.
Major accidents and incidents
Notes
see also
| hydroelectric power plant in Wiktionary | |
| hydroelectric power plant at Wikimedia Commons |
Links
- Map of the largest hydroelectric power plants in Russia (GIF, 2003 data)
| Industries | |
|---|---|
| Power industry | Nuclear (NPP) | Wind (WPP) | Hydropower (HPP) | Thermal (TPP) | Geothermal | Hydrogen | Solar energy | Wave | Tidal (PES) |
| Fuel | Gas | Oil | Peat | Coal | Oil refinery | gas processing |
| Ferrous metallurgy | Extraction of ore raw materials | Mining of non-metallic raw materials | Ferrous metal production | Pipe production | Production of electroferroalloys | Coke | Secondary processing of ferrous metals | Hardware production |
| Non-ferrous metallurgy | Production: aluminum | alumina | fluoride salts | nickel | copper | lead | zinc | tin | cobalt | antimony | tungsten | molybdenum | mercury | titanium | magnesium | secondary non-ferrous metals | rare metals | Industry of hard alloys of refractory and heat-resistant metals | Extraction and enrichment of ores of rare metals |
| Engineering and metalworking |
Heavy | Railway | Shipbuilding | Ship repair | Aviation | Aircraft repair | Rocket | Tractor | Automotive | Machine tool | Chemical | Agricultural | Electrotechnical | Instrumentation | Precise | Metalworking |
| Chemical | Mining and chemical | Basic chemistry | Paint and varnish | Household chemicals industry | Soda production | Fertilizer production | Manufacture of chemical fibers and threads | Production of synthetic resins |
| Chemical-pharmaceutical | |
| petrochemical | Tire | Rubber-asbestos |
| Oil refinery | |
| Lesnaya (complexes) |
Forest | Woodworking (Sawmill, Wood-board, Furniture) | Pulp and paper | Wood chemical |
| building materials | Cement | Reinforced concrete and concrete structures | Wall materials | nonmetallic building materials |
| Glass | |
| Porcelain-faience | |
| Light | Textile | Sewing | Tannery | Fur | shoe |
| Textile | Cotton | Woolen | Linen | Silk | Synthetic and artificial fabrics | Hemp-jute |
| food | Sugar | Bakery | Oil-fatty | Butter and cheese | Fish | Dairy | Meat | Confectionery | Alcohol | Macaroni | Brewing and soft drinks | Winery | Flour mill | Canning | Tobacco | Salt | fruit and vegetable |
| Energy structure by products and industries |
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| Power industry: electricity |
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