Modern tools and methods for diagnosing equipment in the mining and processing industry in accordance with the concept of "Reliable Equipment". Predictive maintenance strategy for computing equipment DSP Proactive maintenance

WELDING. RENOVATION. TRIBOTEKHNIKA: abstracts / Ed. ed. ; Ministry of Education and Science of the Russian Federation; FGAOU VPO “UrFU im. the first President of Russia B.N. Yeltsin, Nizhny Tagil. technol. in-t (fil.). - Nizhny Tagil: NTI (branch) UrFU, 2013. - 76 p.

During repair stops, the mechanisms are revised and worn parts are replaced with new ones. The frequency of repairs can be determined by the frequency of equipment failures − failure repairs. But they take a lot of time, because there is no way to prepare for them. To remedy this, developed scheduled preventive maintenance(PPR), which are performed after a certain operating time. This approach reduces the repair time, but allows for premature repairs, because wear is not repeated with great accuracy. Since the 90s, the presence of malfunctions has been determined vibration diagnostics working equipment. This excludes premature repairs, which is reflected in the name of repairs - according to the actual state(RFS). Further reduction of repairs is possible by increasing the post-repair operating time of the equipment. This is achieved by applying measures to slow down wear; such repairs are called proactive(STEAM). The content of the proactive part of repairs:

• optimization of external impact, including reduction of its peak component (from vibrations, shocks, etc.);
• lubrication optimization;
• hardening of working surfaces.

Optimization of external influence

The external influence that causes wear is determined by the capacity of the equipment. But power reduction results in a drop in performance. However, such a path is possible if the annual production of equipment operating with a lower load, due to small repair downtime, turns out to be greater than in the case of operation with a high load and significant repair downtime and costs.

Another way to optimize the external impact is to reduce its destructive effect without reducing power, by reduction of stress concentration. For example, the body of a 12-meter die for forming large diameter pipes broke in two after a short operation. Its repair welding without additional strengthening measures did not seem promising. An analysis of the stress state of the structure showed that the level of equivalent stresses along the fracture line sharply decreases as a result of a change in the angle of the lower stiffeners by only 7°. The subsequent operation of the modernized stamp confirmed the validity of this decision.

The peak component of the load may appear from malfunctions. Hard surfacing of the ends of the bogies of the firing machines not only reduced the wear and frequency of repairs of the bogies themselves, but due to the fact that the skew of the bogies was simultaneously eliminated, the load on the drive sprocket decreased and the replacement of its sectors decreased by a factor of four.

Vibration creates peak loads. The vacuum generator consists of a container with two nozzles. Through one, the steel melt is sucked into the degasser, and through the other it is drained back into the ladle. The suction pipe during operation created a vibration that destroyed the refractory lining. Fastening elements reduced vibration and doubled the resistance of the vacuum cleaner.

Lubrication optimization

The lubricant is a layer that converts the external (large) friction of the surfaces into the internal (small) friction of the lubricant. There are liquid lubrication, when the friction surfaces are separated by a continuous stable layer of lubricant, and boundary lubrication - with a thinner and intermittent oil layer. Liquid lubrication is provided by a special arrangement of bearings, and boundary lubrication is obtained as a result of free placement of lubricants on friction surfaces. As the latter, oils of animal and vegetable origin were historically the first to be used. In the last quarter of the 19th century, the production of cheaper mineral oils from petroleum began. Their properties were not so good, so there was a long process of improving them with additives. The emergence of synthetic oils dates back to the middle of the 20th century. With a low temperature dependent viscosity and chemical stability, they provide better lubricating properties resulting in reduced friction and wear compared to petroleum oils.

In the 1930s it became known rebinder effect. He showed that friction can reduce an extremely thin (5 nm) layer surfactants(surfactant), which can be called "invisible lubricant". To apply surfactants to the surface in the West, a solution called "Epilam" was developed. In the future, new surfactant solutions, by analogy, continued to be called epilams, assigning an original name (brand) to each. In the 60s, EN-3 epilam, a solution of stearic acid in isooctane, was developed at NIIChasprom. Then epilams based on fluorinated surfactant appeared and are being improved. For example, a 0.05% solution of perfluoropolyether acid 6MKF-180 in Freon 113 (Epilam Efren-2). Epilamic “invisible lubrication” does not cancel the use of conventional lubrication, but increases its effectiveness (reducing friction and wear) by eliminating the contact of rubbing surfaces with unlubricated areas. Epilamation provides for preliminary degreasing of the surface, wetting it with epilam and air drying, which is quite accessible for use in repairs.

In the 60s, scientific discovery No. 41 was registered in the USSR - the “wearlessness effect”. Its essence is that from a lubricant containing fine particles, their thin layer is deposited on the friction surfaces. Behind him is the ability to wear and restore as the gap between the friction surfaces increases. Thus, despite friction and wear, the primary surfaces of the parts, being protected by the deposited layer, remain wear-free. Hence the origin of the name “effect of wearlessness”. To achieve it, dispersed powders of soft (copper, serpentinite, fluoroplast) and hard (ceramics, diamond) materials are added to oils. The most stable ideas about them are as follows. Copper additives do not hold well on the surface, so their constant presence in the lubricant is required. Serpentinite has the ability to diffuse to create a durable layer with a low coefficient of friction. Solid particles of diamond and ceramics, filling microroughnesses, create some kind of rolling bearing. Oil additives achieve restoration of wear without disassembly of mechanisms and reduction of friction.

Optimization of the choice of lubricants can be supplemented by the improvement of systems for delivering them to friction units. This, without capital investments, extends the time between overhauls of equipment.

Hardening of working surfaces

For all combinations of friction pairs, there is a certain range of loads and friction velocities, in which the wear is several orders of magnitude lower than outside this range. In mechanical engineering, there is a continuous search for ways to move the specified range to higher pressures and velocities. In this case, hardening plays an important role. In the third quarter of the 20th century, its widespread use (HFC hardening, carburizing, nitriding, surfacing, spraying, etc.) made it possible to significantly slow down wear and increase (up to a micron level) the accuracy of parts manufacturing. Without hardening, increasing the accuracy does not make sense, because in this case, expensive micron mates, due to rapid wear, turn into ordinary ones already at the beginning of operation. Thanks to micron fitting of parts, gaps are minimized, noise, dynamic loads, vibration are reduced, it becomes possible to work with minimal wear at high speeds. Adjusting elements were removed from the mechanisms, which serve to select gaps during rapid wear, which also had a positive effect on the reliability of machines and equipment. New generation machines increased the operating time so significantly that they were called "non-repairable".

The hardening coverage of the functional surfaces of machines is not yet optimal, so hardening work during repairs is fully justified. Let's pay attention to carbonitration and manual plasma hardening. They were developed not so long ago, but they have prospects for use, especially during repairs, as they belong to the finishing category.

carbonitration- developed in the USSR in the 70s and represents the saturation of the surface with nitrogen and carbon in the melt of potassium cyanate salt. The properties of the carbonitrated layer are similar to those of the layer obtained by nitriding. On the surface there is a thin layer (about 5 microns) of solid carbonitride, under which there is a layer saturated with nitrogen (0.2 mm) with gradually decreasing hardness. The difference is that only alloy steels are strengthened by nitriding, while carbonitration can strengthen ordinary carbon steels ().

Table 1 - Hardness of carbonitrated surfaces (measurements were made with an ultrasonic hardness tester UZIT-3)

Carbonitration does not require as thorough pre-treatment as nitriding and is much faster (2 hours instead of 48 hours) than nitriding. Machine parts can be manufactured according to drawing dimensions and immediately after carbonitration they can be put into operation. This reduces the complexity of manufacturing, acquires wear and corrosion resistance. For example, the use of carbonitration instead of HDTV hardening reduced the consumption of the drive gear shafts of the gearbox of the SBSh-250 drilling rig by 6 times.

1.1. The system of maintenance and repair of enterprise equipment

Under MRO system means a set of interrelated means, documentation and performers necessary to maintain and restore the quality of products included in this system.

As goals MRO systems are defined as follows:

• maintenance of equipment in working condition during the entire period of operation;
• ensuring reliable operation of equipment;
• ensuring the productivity and quality of products;
• compliance with the requirements for labor protection and environmental protection.

The organization of the MRO system of the enterprise is carried out on the basis of the adoption (explicitly or in accordance with established practice) of decisions on the following fundamental issues ():

• choice of equipment maintenance and repair strategy;
• determination of the method of organizing repair maintenance of production;
• development of criteria for assessing the effectiveness of repair maintenance of production.

Figure 1.1 - Fundamental issues in the organization of the maintenance and repair system

1.2. Equipment Maintenance and Repair Strategies

Under maintenance strategy implies a generalizing model of actions necessary to achieve the goals by coordinating and distributing the appropriate resources of the enterprise. In essence, the maintenance and repair strategy is a set of decision-making rules that guide the repair service (RS) of the enterprise in its activities to ensure the operability of equipment.

A brief description of the main maintenance and repair strategies is given in.

Table 1.1 - Brief description of the main maintenance and repair strategies

Under reactive maintenance and repair strategies are implied, the need for repair actions in which is determined by the onset of some critical event within the framework of this strategy (failure, reaching the limit values ​​of regulated parameters). preventive maintenance and repair strategies are aimed at preventing the occurrence of a critical event and are characterized by the possibility of carrying out preliminary planning and preparation of maintenance and repair (ordering repair teams, logistics) as opposed to reactive strategies, when it is necessary to conduct maintenance and repair, and, accordingly, ensuring their preparation, before the onset of a critical event unpredictable.

Historically, the first (as the least demanding in terms of the level of organization and work culture) has developed operation to failure strategy, which implies the implementation of equipment maintenance and repair operations to achieve a critical state, which, as a rule, is characterized by the impossibility of performing the specified functions, that is, the loss of operability. The main advantages of this maintenance and repair strategy include the longest overhaul period corresponding to the service life of the equipment, and the minimum cost of maintaining the repair service, the dominant function of which in this case is the restoration of the equipment after its failure. On the other hand, the lack of the ability to plan resources (financial, time, labor, and others) required to perform maintenance and repair leads to a significant increase in the duration of the latter and to increased costs for the elimination of accidents, including production losses. The creation of warehouse stocks of inventory items, as a rule, is not a satisfactory solution, since it entails a decrease in the liquidity of the enterprise. The volume of such reserves in a number of cases (especially in industries where unique single equipment is used) exceeds economically justified limits. Despite these shortcomings, in the case of inexpensively redundant, as well as typical equipment, the failure of which does not have a critical impact on the technological process, does not pose a danger to the environment, human health and life This strategy has been successfully used to this day.

In the first half of the 20th century, with the growth of serial production and the increase in the productivity of industrial enterprises, losses due to equipment failures became critical. The strategy of operating to failure has been replaced by PPR strategy or repairs according to the regulations, implying preventive maintenance and repair based on statistical information about the service life of equipment. Reducing the number of emergency failures is one of the main advantages of this strategy, although the probability of their occurrence is not completely excluded, but is fixed within the specified limits. The PPR strategy provides the best conditions for resource planning, “however, the main drawback of the PPR outweighs all its advantages, it consists in carrying out repairs of actually serviceable equipment, as well as the forced replacement of parts, regardless of their remaining resource (in complex equipment, the difference in the resources of individual parts can reach 500% ). All this leads to an unjustified increase in operating costs. The disadvantages of the PPR also include a decrease in the residual life of the equipment and an increase in the probability of failure when commissioning after repair. This strategy provided the best integration within the planned economy and allowed to eliminate a number of shortcomings of the historically established earlier operation to failure strategy. A more complete use of the resource of the equipment was achieved by reducing the likelihood of damage to parts with a potentially long resource. , which could have occurred in the event of failure of the elements that determined the service life of the equipment as a whole during operation to failure. Currently, the PPR strategy continues to be used at many enterprises, primarily for critical equipment and equipment, the failure of which can pose a danger to the environment, human health and life. In other cases, the PPR strategy is often applied only declaratively, which is due to the increased requirements for the efficiency of the MRO system of an enterprise in a market economy.

On the border of the 70-80s of the XX century, mobile and portable vibration measuring equipment was used in the repair service of production, which allows vibration monitoring of equipment based on frequency analysis. At the same time, there was an accelerated development of the theory of reliability and research in the field of operational properties of equipment. All this predetermined the emergence of a new scientific and applied field of knowledge - technical diagnostics, the achievements of which were used as the basis for the implementation of the maintenance and repair strategy by TS. First of all, the maintenance and repair strategy for the TS is aimed at eliminating the shortcomings of the outage strategy that historically preceded it, namely, at reducing the number of unreasonable repair actions in order to maximize the use of the equipment resource. When applying this strategy, by monitoring the vehicle, the probability of emergency equipment failures is reduced to a possible minimum. The motto of this strategy is: “Equipment should be shut down for repairs an instant before the expected failure”. Reducing the cost of maintenance and repair of equipment, minimizing the number of unplanned failures, reducing the number of planned downtime due to installation and assembly operations are the undeniable advantages that accompany the implementation of the maintenance and repair strategy for TS. The maintenance and repair strategy for the vehicle put forward new requirements for the level of work culture. Within the framework of repair services and regulatory bodies, technical diagnostics units are singled out, the importance of personal professionalism, qualifications and experience of workers, managers and specialists is increasing. On the other hand, since the maintenance and repair regulation is determined by a stochastic factor - the actual technical equipment of the equipment - the effectiveness of long-term resource planning decreases (the approximate period for preventing failures, and hence planning for maintenance and repair, in the case of using technical diagnostic tools, mainly does not exceed two to three months).

In order to ensure high performance indicators of equipment of industrial enterprises, it has recently become increasingly popular proactive strategy MRO. The analysis carried out in the work allows us to determine the proactive maintenance and repair strategy as the most effective and expedient for implementation in modern economic conditions. The proactive strategy combines the advantages of the preventive repair effects of the PPR system and the information support of the decision-making process, which is typical for maintenance and repair of equipment TS.

1.3. Proactive equipment maintenance and repair strategy

Essence The proactive equipment maintenance and repair strategy consists in performing the necessary repair actions aimed at reducing the rate of development or eliminating malfunctions that are identified based on information about the actual equipment TS.

Theoretical basis of the proactive equipment maintenance strategy postulate that initially all types of faults are present in embryonic or explicit form in all machines put into operation. Various factors accompanying operation (design and non-design loads, the impact of environmental factors and nearby equipment, operating conditions, maintenance and repair, and others), to one degree or another lead to the development of various types of malfunctions. The determining effect of a combination of factors causes the accelerated development of one or more faults, which become determining in relation to the machine's performance. By choosing repair actions in such a way as to reduce the influence of the determining factors, it is possible to reduce the rate of development of faults, maintaining the operable state of the machine. Rational choice and quality implementation these and only these repair impacts is the task of RS.

The proactive maintenance and repair strategy () is based on evaluation of the technical equipment of the equipment which can be done in the following ways:

• monitoring of technological parameters;
• visual inspection;
• temperature control;
• acoustic and vibration diagnostics;
• inspection using non-destructive testing methods (magnetic, electrical, eddy current, radio wave, thermal, optical, radiation, ultrasonic, penetrating substances).

Figure 1.2 - Repair maintenance of equipment as part of a proactive MRO strategy

Basis for acceptance decisions on the need to carry out a repair action is a situation when the TS of one element (part, assembly, mechanism) of the equipment leads to the deterioration of the TS of adjacent (spatially and / or functionally) elements.

List of possible repair impacts:

• maintenance of equipment (cleaning, cleaning, anti-corrosion treatment);
• adjustment, adjustment, adjustment (centering, balancing);
• provision of connections (restoration of the integrity of welds, tightening of threaded connections);
• lubrication of friction surfaces;
• replacement of wearing parts;
• restoration or replacement of basic parts, including body parts.

Repair actions are carried out within the framework of the following groups of activities for maintenance and repair of equipment:

1. Preventive Maintenance- a set of measures taken periodically, which are aimed at preventing or reducing the rate of development of defects by ensuring the design conditions for the interaction of equipment components (cleaning from technological waste, wear products, corrosion, sediments, deposits, etc.; removal of dust, dirt, oil, slag, scale , spillage of raw materials, debris, etc.; topping up, refueling working fluids, topping up, replacing consumables; replacing or restoring replaceable equipment, etc.).
2. Corrective Maintenance- a set of measures taken as necessary, which are aimed at preventing or reducing the rate of development of defects by ensuring design conditions for the interaction of equipment units (adjustment and adjustment of equipment, including centering, balancing; restoration of connections of parts, ensuring the integrity of metal structures and pipelines; restoration of coatings, colors, etc.).
3. Predictive Maintenance- a set of measures aimed at establishing the actual TS of the equipment in order to predict its change in the course of further operation and identify the most appropriate moment of application and the required types of repair actions (measuring technical and technological parameters, sampling; control, testing, verification of equipment operation modes; control TS of equipment, including methods of technical diagnostics; flaw detection by non-destructive testing methods; technical inspection of equipment, survey, examination, revision, etc.).
4. Maintenance- a set of measures aimed at ensuring the operability of equipment by replacing or restoring its individual components that are not basic, except for replaceable equipment.
5. Overhaul- a set of measures aimed at ensuring the operability of equipment by replacing or restoring its basic components and parts.

Selecting a proactive maintenance strategy makes it possible to provide:

• increasing the service life of equipment by reducing the rate of development or eliminating emerging faults at the initial stage of their occurrence;
• exclusion of secondary damage to equipment elements caused by failure of adjacent (spatially and/or functionally) elements;
• justification and implementation of only the necessary repair actions, which reduces the costs and load on the distribution system, and also reduces the likelihood of failures caused by installation errors and interference with the operation of operable equipment;
• reduction in the cost of repair maintenance of production, due to a change in the structure of maintenance and repair in favor of increasing the number of inexpensive preventive actions instead of costly repair operations (replacement, restoration);
• rational choice of time, types and volumes of maintenance and repair due to early warning of malfunctions when using methods and means of technical diagnostics and non-destructive testing;
• reduction of the probability of emergency failures due to unsatisfactory technical specifications of the equipment;
• increasing the availability of equipment, which provides an opportunity to increase production volumes and reduce the cost of production;
• the formation of consumer confidence in the manufacturer due to the timely fulfillment of contractual obligations and the improvement of product quality as a complex result of improving the work culture.

1.4. Ways to organize repair maintenance of production

Organization method repair maintenance of production determines the structure of the RS of the enterprise, which has a direct impact on the efficiency of the MRO system as a whole.

Classic ways RS organizations are characterized by a range of forms from decentralized to centralized, which differ in the degree of concentration of management of forces and means within a single specialized structure at the enterprise ().

Figure 1.3 - Classical methods of organizing repair maintenance of production

The method of organizing repair maintenance, characterized by the distribution of forces and means of the RS between the production units of the enterprise, is called decentralized.

Centralized organization of the RS implies the presence of a specialized structure within the enterprise, which is entrusted with the entire scope of functions for the maintenance and repair of equipment of production and auxiliary divisions, as well as bearing full responsibility for ensuring the operability of the equipment.

The method of constructing a DC based on a wide range of intermediate forms that differ in varying degrees of centralization is called mixed.

The most common at domestic enterprises are mixed forms of RS organization, while foreign practice indicates the high efficiency of centralized forms of equipment maintenance and repair, including the construction of a maintenance and repair system based on alternative methods of organizing RS.

Alternative ways organization of repair maintenance of production () implies the involvement of external resources (forces and means) to ensure and carry out maintenance and repair of enterprise equipment. Depending on the degree of use of the resources of external enterprises and the transfer of appropriate responsibility for ensuring the operability of the equipment, there are contracting And service ways to perform maintenance work.

Figure 1.4 - Alternative ways to organize repair maintenance of production

To ensure the required level of effectiveness of the equipment maintenance and repair system, the joint use of classical and alternative methods of organizing repair maintenance of production at the enterprise is widespread.

1.5. Criteria for assessing the effectiveness of repair maintenance of production

Efficiency mark repair maintenance of production is carried out on the basis of criteria adopted by the enterprise. An effective system of criteria makes it possible to analyze not only the actual effectiveness of the existing maintenance and repair system, but also quickly identify its shortcomings, determine ways for further improvement and development.

There are technical and economic approaches to assessing the effectiveness of the enterprise's RS. Technical approaches are characterized by a predominant focus on assessing the criteria that characterize the performance of the equipment, the possibility of its use for the implementation of a given technological process. Economic approaches make it possible to evaluate the effectiveness of the RS by comparing the costs of maintenance and repair and production losses caused by the technical equipment.

At present, the question is generalized technical and economic Evaluation of the effectiveness of repair maintenance of production, which would allow a comprehensive analysis of the effectiveness of the equipment maintenance and repair system, should be classified as insufficiently developed, which leaves room for enterprises to develop their own approaches to its solution. The indicated, for example, was undertaken in [ , ].

It is necessary to pay special attention to a common mistake. To assess the effectiveness of the maintenance and repair system, it is unacceptable to use criteria characterizing the activities carried out by RS (volumes of work performed: in quantitative, temporary, natural, cost and other similar indicators). The intensity of repair work often does not indicate the achievement of the main goal of repair maintenance of production - ensuring the operability of equipment. Evaluation of the effectiveness of the system should be carried out on the basis of external, and not internal indicators of its work.

Only an effective method for evaluating the efficiency of production repair maintenance makes it possible to perform a qualitative analysis of the maintenance and repair system, the effectiveness of the RS activities, and provide information support for the decision-making process.

1.6. accident rate

Industrial equipment accidents lead to the interruption of the technological process, which is accompanied by inevitable material losses, and can also be the cause of man-made disasters and deaths. Ensuring the operability of equipment with the transition from eliminating the consequences of accidents to preventing their causes is the main task of the RS of the enterprise.

To assess the accident rate of equipment, operational (total downtime) or economic (loss of production, cost of eliminating accidents) indicators can be selected. In this case, in the general case, it is advisable for an enterprise to evaluate not absolute values, but rather the dynamics of changes in the selected parameters over time.

On the other hand, a comparative analysis of weighted accident rates (suppose the sum of production losses and the cost of eliminating accidents for a certain reference period, related to the sum of equipment maintenance and repair costs) of industry enterprises may be of interest in order to identify the most effective forms of organization and methods for improving RS.

The assessment of accident rate indicators can be successfully used as an indicator of the effectiveness of measures to reform the RS, to assess the implemented technical and organizational solutions. Based on a comparison of economic losses from accidents and funds allocated for financing the RS, their optimal volumes can be established. The same is true for estimating the number of maintenance personnel.

Regulations and systems that determine the procedure for investigating accidents at industrial enterprises, as a rule, are developed on the basis of the "Procedure for Investigation and Recording of Accidents, Occupational Diseases and Accidents at Work", approved by the Resolution of the Cabinet of Ministers of Ukraine No. 1112 of 25.08.2004. However, the main problem often remains unresolved. We are talking about the full and effective use of the information obtained during the investigation, and not so much to eliminate, but to prevent subsequent accidents on the same or the same type of equipment.

An accident investigation involves a phased solution of the following sequence of tasks:

1. Collection of factual information about the incident and operational actions of the personnel, visual inspection of the place and object of the accident.
2. Studying technological and technical characteristics of the object of the accident.
3. History analysis facility (similar accidents, maintenance and repair work).
4. Formation of a working hypothesis conducting additional research if necessary (if additional research refutes the hypothesis, a new one is put forward, the reliability of which is being verified).
5. Determination of causes accident, accompanying technical factors, perpetrators (development of a confirmed working hypothesis).
6. Development emergency events.
7. Monitoring implementation of emergency events.

The information obtained can be used in solving a number of technical and technological issues, issues of material supply, personnel management, development of the RS.

It seems appropriate to perform the following types of analysis:

• causal, which consists in identifying the characteristic problems of the enterprise (for example, insufficient qualifications of operating personnel, lack of stable and timely logistics, inconsistency in the volume and frequency of equipment repairs to the intensity of its operation, and others);
• spatial, the purpose of which is to determine the "vulnerabilities" of both individual machines and units, the complex of equipment of the enterprise as a whole;
• temporal, which is aimed at identifying seasonal patterns, cyclical nature of emergencies, trends and forecasts of their occurrence.

The results of the analysis are the basis for the development of measures aimed not only and not so much at combating the consequences of accidents, but to a greater extent at eliminating their causes and preventing the possibility of recurrence in the future. [

At present, in accordance with the IEC 61850 protocol, computing equipment is widely used at the bay and substation levels. Its main tasks include the monitoring and control of intelligent electronic devices such as protection relays, PMUs (vector measurement units), interface devices, digital oscilloscopes (recorders) and GOOSE/SMV analysis devices. In addition, computers at the DSC are used for environmental monitoring and surveillance systems.

Any problems in the operation of computing equipment, not to mention its failure, can directly affect the operation of a single substation and the power system as a whole. Therefore, the reliability and performance of substation computers is a key factor in the efficient operation of the substation, and the management of the entire set of computer technology is of particular importance along with other critical substation equipment.

Why is preventive maintenance of DSP computing equipment necessary?

Three typical approaches to the operation and maintenance of equipment (including computers) are implemented at electrical substations:

1. Post-accident maintenance (in case of equipment breakdown or its MTBF)

With this approach, the equipment remains in operation until it breaks down. Repair or replacement of damaged equipment occurs only after the problem has already occurred. Although this approach is used in some substations, it is not recommended for critical substation equipment, including computing.

2. Scheduled maintenance

Maintenance activities are performed at predetermined intervals. For computing equipment, scheduled maintenance is much more preferable than post-disaster maintenance. According to a number of studies, the transition from post-accident to planned maintenance saves users from 12% to 18% of the allocated funds.

However, scheduled maintenance has its drawbacks:

• If equipment malfunctions occur before the planned maintenance time, then this situation is reduced to post-accident maintenance.
• Sometimes, during scheduled maintenance, an excessive (in excess of the required) volume of activities is performed.
• Scheduled maintenance can be very labor intensive.

3. Preventive Maintenance (COP)

Such maintenance is performed when periodic monitoring of the equipment reveals a clear trend towards deterioration. As a result, defective equipment is replaced before obvious problems occur. Preventive maintenance allows you to achieve cost savings in the range of 8-12% compared to the cost of scheduled maintenance.

For sure, it will not be news to you that today the maintenance of DSP computing equipment is increasingly based on the last of the above approaches. Substation computers are now classified as “critical equipment” and included in a preventive maintenance program.

Many substation operators and system integrators also include computing hardware specifications in their tender specifications. For example, an important part of the competitive requirements is to support the required values ​​of CPU load and memory usage of computers involved in data processing and communication processes in substations. Some typical requirements specified in tenders are presented in the following table:

Preventive maintenance strategy is effectively and fully implementedin the event that the personnel have the knowledge, skills and time necessary to carry out the relevant activities. A preventive maintenance strategy allows you to systematically carry out repairs and refurbishment of equipment in a planned manner and at the same time have a lead time for the supply of materials required for repairs, thus reducing the need for a certain set of key spare parts. Since maintenance work is only performed when needed, there is also an increase in the production capacity of the facility. While the initial investment in diagnostic equipment, software, and staff training is required to move to preventive maintenance, the benefits of using this type of maintenance quickly outweigh these costs. This approach to maintenance is generally recognized as the best option for critical substation equipment.

How is preventive maintenance implemented at substations

Most computers these days come with built-in hardware monitoring tools. This feature is implemented at the BIOS level or as part of the operating system.

BIOS-level hardware monitoring

Most modern computer components contain sensors that monitor things like temperature, power consumption, and fan speed. One of the options for reading the values ​​of these parameters is to monitor the hardware at the BIOS level. However, you can access the BIOS only at the stage of booting the computer.

Performance monitoring

The limited functionality of system performance monitoring tools offered by the Windows and Linux operating systems typically extends only to system temperature and some other parameters, which may not be enough to implement a predictive maintenance strategy.

Windows

Select the Performance tab in the Windows Task Manager to view your computer's performance over time.

Below are some of the Linux operating system tools that you can run from the command line and use to monitor your computer's performance.

• VmStat - Virtual memory statistics.
• Iotop - Linux disk I/O monitor.
• Monitorix - System and network monitoring.
• Collectl - High performance all-in-one monitoring tool.

The key to proper predictive maintenance of computers is to use the hardware monitoring feature in the BIOS and the performance monitoring tools included with the operating system to determine the status of key components and use a tool to continuously monitor these values. Users should be able to define thresholds for key computer components and monitor the health of those components against the thresholds they set. If the parameters of key components exceed the threshold values, then the system must be programmed to automatically generate an alarm.

However, most of the solutions available on the market today can only monitor the system temperature and some other parameters, which are clearly not enough to implement a complete predictive maintenance strategy for DSP computers. Furthermore, many systems do not provide users with the ability to define thresholds for key computer components, and may not include an alarm function. If your substation uses predictive maintenance, the simplest approach is to use existing monitoring tools to read the parameters of key computer components and then feed that data into your existing preventive maintenance system. Thus, the system will be able to issue alarms based on the set thresholds for these critical components.

Moha solution

Moha's preventive maintenance solution (so-called Proactive Self-Maintenance) includes the following components:

• • service software (utility) for proactive monitoring;
  • centralized solution for proactive remote alarms.

Proactive monitoring utility

Moxa's utility software, Proactive Monitoring, is a space-saving, lightweight, and easy-to-use utility that allows you to monitor a range of system parameters.

Proactive Monitoring uses hardware sensors located on the Moha motherboard to monitor key components of your computer. You can view the current settings for the computer components of interest by simply clicking the appropriate buttons on the user interface. User-defined related equipment indicators (KPIs) are used to monitor critical components. Visual and/or audible alarms are triggered automatically when a relay is triggered or internal SNMP traps are latched when KPIs exceed their thresholds. For operators, this is very convenient, as it allows you to plan maintenance activities in advance and not turn off the system immediately before the start of maintenance.

Moha's centralized proactive Ethernet-based remote alarm solution

Moha's ready-to-use proactive alarm solution offers the following benefits:

• • Centralized visual/audible alarm at the Control Room (CPU) via Ethernet.
  • For signaling needs on the computer, the installation of output relays is not required.
  • There are no cable restrictions.
  • Combined intra-system SNMP traps (traps) allow you to capture system errors more quickly and accurately.

conclusions

Currently, substation systems are actively involved in the implementation of digital automation at facilities. This trend is supported by advances in information technology, which provide substation operators with the ability to “digitize” substation operations, expand communication interfaces down to the substation's primary equipment, and enable more efficient monitoring and control. Computing equipment plays a critical role in the creation of digital substations, and adequate maintenance strategies help to increase the life of this equipment. The approach to maintenance of computers in substations is increasingly shifting towards predictive maintenance (also known as condition-based maintenance). A well-organized preventive maintenance schedule allows you to foresee the need for appropriate actions, which ultimately leads to time optimization, increased equipment reliability and reduced maintenance costs.

For any questions regarding devices manufactured by Moxa, please contact

Ministry of Education and Science of the Russian Federation

Federal State Autonomous Educational Institution

"Ural Federal University

named after the first President Yeltsin

Nizhny Tagil Institute of Technology (branch)

V. A. Korotkov

PROACTIVE REPAIRS

IN THE MINING AND METALLURGICAL INDUSTRY

Nizhny Tagil Institute of Technology (branch) UrFU

named after the first President Yeltsin

as an electronic text teaching aid

for students of all forms of study

Nizhny Tagil

Reviewer:

Dr. tech. Sciences

Scientific editor:

Dr. tech. sciences, prof.

Proactive repairs in the mining and metallurgical industry: study guide. allowance / V. A. Korotkov; Ministry of Education and Science of the Russian Federation; FGAOU VPO "UrFU im. the first President Yeltsin, Nizhny Tagil. technol. in-t (fil.). - Nizhny Tagil: NTI (branch) UrFU, 2013. - 41 p.

The manual outlines the basic principles and methods for increasing the after-repair operating time of equipment. Including due to the optimization of workloads and stresses, hardening of the functional surfaces of parts, the use of qualitatively new lubricants.

It is intended for students, graduate students and production specialists.

UDC 621.791

BBC 34

Bibliography: 41 titles. Tab. 11. Fig. 14.

The disadvantages of machines are especially clear

found out during the repair. Essentially, their refinement

starts only after commissioning

From the directory

"Design Fundamentals"

Foreword

In the mining and metallurgical industry, repair costs can absorb a significant part of income, and repair downtime can significantly reduce income itself. Therefore, reducing both of them is an urgent task. The main directions of its solution:

– prevention of sudden (emergency) failures;

– exclusion of premature repairs;

- reduction of the duration of repairs due to the aggregate principle;

– increase in the service life of parts due to hardening, lubrication, etc.;

- restoration of worn parts, which is more economical than buying new ones.

In the past two decades, the arsenal of tools to reduce repair costs and downtime has expanded significantly. To prevent accidents, flaw detection (magnetic powder, ultrasonic ...) is carried out, the instruments for which are constantly being improved. Vibrodiagnostics devices detect not only cracks, but also wear and assembly defects, i.e., they establish the need for repairs without stopping it and disassembling the equipment. Such repairs are called “repairs according to the actual state”, because they exclude the carrying out of premature repairs when the equipment is not yet worn out enough. Portable devices for determining hardness, roughness, chemical composition, check for compliance with the drawings, arriving for replacement, spare parts, which eliminates the entry into operation of "defective" and the subsequent rapid failure of the repaired equipment. Oils with tribological additives not only reduce friction, but also restore wear without disassembling mechanisms. Manual plasma hardening has become available to harden contact surfaces on large-sized equipment cases. Methods for the restoration of worn parts significantly reduce the purchase of spare parts.

Thus, mechanics during repairs have the opportunity not only to restore the performance of the equipment by replacing worn parts, but to apply measures to increase the post-repair operating time. Repaired equipment starts to work better than new. These anti-aging repairs are called " proactive» repairs to which this work is dedicated.

1. REPAIR MANAGEMENT SYSTEMS

During maintenance shutdowns revision mechanisms for determining unacceptable defects, after which it is carried out directly repair, i.e. replacement of rejected parts with new parts. Currently, there are four main forms of organization of repairs. These are failure-to-repair, scheduled preventive maintenance, condition-based repairs, and proactive repairs.

1.1. Failure repairs and outage

It is possible to carry out repairs when its operation becomes impossible due to failure - "failure repairs". This simple strategy does not burden the costs of preparing repairs, but the repairs themselves, due to their unexpectedness, can be costly and lengthy. “Failure repairs” are justified if the failures are of a random nature, little dependent on the operating time, and when the consequences of the failure are insignificant, and preventive measures are more expensive than replacing the failed node.

An improved version of “failure repairs” is “defect repairs”, which are determined by indirect signs: vibrations, oil leaks, etc. To speed up “failure repairs”, the aggregation method is used. The replacement of units is faster than the replacement of individual parts included in the units; at the same time, the units themselves are sent for repair to specialized divisions or enterprises.

Failure of operating equipment due to the failure of one part can lead to damage to other (serviceable) parts, and thus create emergency situations. To prevent them, developed scheduled preventive maintenance(PPR), which are performed after a certain operating time, when it is known from experience that the mechanisms are already in need of repair.

The disadvantage of PPR is as follows. Wear, as a rule, is not repeated with great accuracy, since it depends on changes in hardness, dimensions and location of parts, even within drawing tolerances. Consequently, PPR is actually carried out with a delay or ahead of the objectively necessary repair period. A delay in the repair means equipment failure, therefore, they plan ahead of time for maintenance work. But premature disassembly of the equipment (when the wear of parts has not reached the limit value) and subsequent assembly without replacing parts disrupts the running-in of the mates, causing their accelerated wear. This implies an objective need for a more accurate determination of wear by secondary signs without disassembling the mechanisms.

However, the current PPR system largely suits both the equipment manufacturer and the personnel of the repair organization. The manufacturer prescribes frequent PPR, during which his manufacturing flaws are eliminated. The repair enterprise (subdivision) is interested in the PPR in that this system provides permanent employment with a minimum possibility of quality control of the repair work by the Customer.

1.2. RFS and proactive repairs

Since the 90s, it has been used in repairs vibration diagnostics, i.e., determination of the technical condition of the mechanisms (for the presence of cracks, assembly defects, wear) by the vibration background created by the operating equipment, using portable electronic devices - vibration analyzers. It significantly reduces revision downtime associated with disassembly and inspection of mechanisms. In addition, inventory of spare parts is reduced, as the condition of the mechanisms is continuously monitored, and therefore only the necessary is purchased. Repairs assigned according to the technical condition determined by vibration diagnostics are called “repairs according to the actual condition”.

Vibration diagnostics is conveniently supplemented by electronic failure accounting, which allows you to identify problematic components and parts that most often fail. This information makes it possible to analyze the reasons for their low performance in order to develop measures to increase the service life. Repairs carried out with the implementation of measures to increase the durability (operating time) of replaceable parts and mates began to be called "proactive repairs". After their implementation, the equipment works not only no worse, but even better than the new one. This allows us to say that “proactive repairs” are accompanied by a rejuvenating effect.

The most effective PAR system is also the most difficult to implement. Vibration diagnostics and electronic recording of failures, which is not simple in itself, should be supplemented by the development of measures to slow down wear and the appearance of other defects, which, moreover, must be tested in practice. In other words, proactive repairs involve some form of research and development (R&D). This leads to higher requirements, both for the services of the chief mechanic (energy), and for contractor repair organizations or their own repair departments.

Table 1.1

Comparison of repair management systems

Practice shows that it is not advisable to use only one of the presented repair organization systems. A flexible combination of them gives the greatest effect. In table. 1.1. and 1.2 shows a comparison of various systems for organizing repairs and their ratio recommended by BALTECH for mining enterprises (http://www.*****).

Table 1.2

Shares of repair management systems for enterprises

2. COMPONENTS OF PROACTIVE REPAIRS

After the planning of repairs has been brought to perfection, i.e., they are carried out neither earlier nor later than it is required by the state of the mechanisms, then in order to further reduce repair costs, it is necessary to increase the post-repair operating time. This is achieved proactive repairs, including measures to slow down the failure of mechanisms due to the formation of cracks, wear, and other defects. Including:

– optimization of workloads and voltages;

– hardening of working surfaces;

– improvement of lubrication.

2.1. Workload and voltage optimization

Important design principles are to reduce the weight of machines (equipment) and increase productivity (power). But this leads to an increase in stresses in the structural elements and on the contact surfaces. The growth of stresses in structural elements increases the likelihood of breakdowns, and on contact surfaces it accelerates wear. As a result, there is an increase in the frequency of repairs, the costs of which reduce profits, and repair downtime - income from operation. Therefore, a decrease in the productivity of equipment (workloads) and an increase in its mass can be justified if there is an increase in profit due to a decrease in repair costs and downtime.

The loads perceived by the equipment cause stresses in its parts and details, and create friction on the contact surfaces. It is possible to distinguish between favorable and unfavorable perception of workloads by equipment. With an unfavorable perception, vibration, stress concentration, which lead to rapid failures, take place. Work to eliminate the adverse perception of workloads by equipment, with vibration and stress concentration, gives a significant reduction in repairs. Let's show this with examples.

The body of a 12-meter die for forming large diameter pipes, after a short operation, broke in two along the longitudinal axis. Its repair welding without "strengthening" the structure did not seem promising. However, the actual "strengthening" due to the increase in mass was avoided. An analysis of the stress state showed that a 7º change from the normal to the angle of the lower stiffeners (Fig. 2.1) more evenly distributes the working force over the die body and reduces the level of destructive stresses along the fracture line. Such modernization did not require either an increase in the cost of repairs or an increase in the mass of the structure.

In a continuous casting machine (CCM), the rotation of the rollers often stopped. In this case, the “rolling friction” of the roller against the ingot turned into more aggressive “sliding friction”, which led to rapid wear in the form of “flats” and premature replacement of the rollers. After the rotation of the rollers with axles was replaced by the rotation of the roller barrel on a fixed axle, the cases of jamming of the rollers were eliminated. As a result, the aggressive type of wear "sliding friction" was eliminated, which increased the operating time of the rollers by 2.5 times.

The pressure in the blast furnace is released through the atmospheric valve. To slow down the wear of its contact surfaces by a dusty gas flow, hard facing (HRC55) was used, which was then subjected to laborious grinding. Since the outflow of gases, causing rapid wear, was due to loose contact surfaces, it was decided to seal the joint with refractory asbestos. The outflow of gases decreased so much that, without prejudice to the service life, they switched to a less hard surfacing (HRС35), which is processed by turning, which significantly reduced the labor intensity and cost of repairing the atmospheric valve.

Studies of the wear resistance of a welded branch used to remove dusty gases showed the following. An increase in the steepness of the bend (instead of 5 sectors, 4 were used, Fig. 2.2) led to an increase in the concentration of the force effect of the gas flow so significantly that it repeatedly reduced the service life.

Carts of kilns during movement are in contact with the sides. The wear of the sides leads to the skew of the bogies, which in turn creates an increased load on the drive sprocket. Rapid wear of the sides of the bogies was eliminated by hard surfacing "in size". This simultaneously eliminated the skew of the bogies in the machine, reduced the load on the “sprocket” and, as a result, the frequency of replacing its sectors. If earlier in the “asterisk” one sector was replaced every year (at a cost of ~1 million rubles), now a sector is replaced every four years.

In the degasser, two branch pipes descending into a ladle with steel melt are fixed in a flat bottom. One branch pipe is for sucking the melt into the degasser, the other is for draining the melt back into the ladle. During operation, the suction pipe created vibration, which quickly destroyed the refractory lining, and the degasser was taken out for repair. To reduce vibrations, fastening elements were used, as a result of which the resistance of the degasser doubled, and the cost of vacuuming fell by half.

In welded railway bridges, cracks appear unexpectedly quickly, after only 2–7 years of operation. For a long time they could not find the cause, until in the 90s it was established that high-frequency vibrations occur in the spans of bridges during the passage of trains. To prevent them, traditional connections from rolling angles were replaced with sheet diaphragms, and this eliminated the appearance of cracks, even with 10 times the operating time.

Equipment perception of workloads is greatly influenced by stress concentrators. The term itself suggests that in some places of machines and mechanisms, due to design features, there is an increase in stress. The destruction caused by stress concentrators is different from the destruction from general overloads. When the overload covers the entire section of the part, the destruction is preceded by plastic deformation. But it is absent when the strength condition is violated only in the stress concentrator. For this reason, such destruction is called fragile.

They happen in the following way. In the stress concentrator, even insignificant operating stresses from the own weight of the structure can increase to the level of the ultimate strength of the metal, which leads to the appearance of microcracks. If its sharpness is great and does not subside as it advances, then the crack begins to represent a moving stress concentrator. Since the stress exceeds the tensile strength at the mouth of the crack, it instantly passes through the entire section. Thus, in the absence of payloads, under the influence of only their own weight, bridges and galleries collapsed, tankers went under water.

An important rule for preventing brittle fractures is to prevent the accumulation of stress concentrators (holes, welds, etc.). The result of its non-compliance was the destruction of one of the two beams of the excavator handle, Fig. 2.3 A it can be seen that both parts of the collapsed beam are not deformed, which indicates the brittle nature of the fracture that occurred under a small load.

On fig. 2.3 b one can see the place of the beginning of destruction, which in Fig. 2.3 A marked with a dark arrow. The nucleated crack, before covering the entire section, first advanced gradually, which gave the fracture a fatigue character at the same time.

Electroplating" href="/text/category/galmzvanika/" rel="bookmark">electroplated chromium plating, carburizing, nitriding and some others. Their characteristics are given in Table 2.1.

In proactive repairs, this approach is also acceptable if the parts were previously used without hardening. Otherwise, it is necessary to find methods of hardening that are more effective than those used. With a simple enumeration of the hardening methods available for use, the appropriate method may fall out last, which will lead to loss of time and money. Therefore, it is useful to know some rules to minimize the number of experiments when choosing an appropriate hardening method.

Table 2.1

Characteristics of types of hardening

The choice of hardening methods for the thickness of the hardened layer

If the part is operated to a significant (measured in millimeters) wear, then it is not always necessary to set the hardening to the same thickness. Large wear of mechanisms leads to power losses, to shocks and vibrations that cause breakdowns, and becomes the reason for the production of low-grade products. Therefore, hardening should be considered not only as a means of reducing the consumption of spare parts, but also as an opportunity to eliminate the operation of equipment with high wear. Hardening can repeatedly (even tens and hundreds of times) slow down wear, so that the need to operate mechanisms with high wear is eliminated.

UDC 629.7.05

PROSPECTS FOR THE DEVELOPMENT OF TECHNICAL MAINTENANCE METHODS FOR COMPLEX ON-BOARD EQUIPMENT SYSTEMS

©2012 N. V. Chekryzhev and A. N. Koptev

Samara State Aerospace University named after Academician S.P. Korolev (National Research University)

The article discusses the principles of a qualitative approach to a promising method of proactive maintenance of complex systems of airborne equipment.

Flight safety, risk management, failure evolution, proactive maintenance.

Over the past 30 years, the main task of the development of the air transport system has been the search for new approaches to solving the problem of improving the safety of aircraft (AC) flights.

It is obvious that the traditional reactive (Reactive) ideology of prevention of aviation events, built on strict compliance with regulatory requirements and the implementation of preventive recommendations developed based on the results of the investigation of the events that have occurred, has exhausted itself.

Therefore, ICAO has developed a fundamentally new ideology for the prevention of aviation accidents and incidents, called "flight safety management".

The new ideology of aviation accident (AAC) and incident prevention involves the creation of a flight safety management system (SMS) in the airline, which:

Identifies actual and potential security threats;

Ensures that corrective actions are taken to mitigate risks/hazards;

Provides continuous monitoring and regular assessment of the achieved level of flight safety.

SMS is not focused on anticipating a negative event, but on identifying

dangerous factors in the aviation system that have not yet manifested themselves, but can cause incidents, accidents and disasters. This approach to the prevention of aviation accidents was called "proactive" (Proactive).

In essence, proactive maintenance assumes the same reactive approach as condition-based maintenance with parameter control (TEP), but such system parameters are selected as diagnostic signs, the observation of which allows one to control the root causes of the degradation of system stability factors (Fig. 1).

The accumulated experience of investigating aviation events has shown that each of them was due to the impact of several causes that were hidden for a long time in the form of shortcomings (dangerous factors or risk factors) of the components of the aviation system.

Five basic structural elements of the concept of flight safety underlie the Reason model (Fig. 2).

Flight safety measures should be aimed at controlling organizational processes containing hidden conditions in the form of deficiencies in the design of equipment, omissions in personnel training, etc., as well as to improve conditions at the workplace.

Rice. 1. Structure of proactive maintenance

Rice. 2. Rizon model

A tool for analyzing the components and features of operational contexts and their possible interactions with people is the SHEL(L) model (Figure 3), designed to give a general idea of ​​the relationship of individuals with the components and features of the workplace.

The strategies and methods of aircraft maintenance considered above are aimed at eliminating mostly obvious malfunctions and failures of aircraft functional systems (FS) products.

Rice. 3. Model BIETS)

The accumulated experience and practice of investigating aviation events prove that the presence of any hidden flaw in the system in the form of a dangerous factor or risk factor can, under certain conditions, lead to its transformation into a cause, which causes a subsequent negative event.

Therefore, ICAO proposed to change the content of the preventive work of the flight safety model (FSM) to conduct targeted work to identify and eliminate

hazards in each component of the aviation system of the flight safety management model (FSM) (Fig.

When implementing BP management (UBM), the content of preventive work is determined by hazardous factors (HF) of the aviation system components. Therefore, in accordance with a proactive approach, airlines are developing special methods designed to assess the degree of risk of predicted events.

Rice. 4. Models for ensuring (OSP) and management (UBM) of flight safety: OD - erroneous actions, OP - dangerous factors, I - incidents, SI - serious incidents, A - accidents, K - catastrophes

The practical basis of safety management is risk management, the methodology of which is set out in the Safety Risk Management Programme. The transition from ensuring (OSP) to flight safety management (FSM) in practice means carrying out preventive work before the development of an aviation event by identifying and eliminating sources

hazards (risk factors) in all components of the aviation system.

Maintenance costs currently account for 12 to 18% of direct operating costs.

In accordance with the requirements of ICAO, one of the most promising methods today is the method of proactive (proactive) technical

Proactive Maintenance, based on the use of predictive analysis technology (Predictive Analytics) from Macsea.

Based on the collection and processing of information, the technology allows predicting further developments, implemented in the Macsea Dexter package, which can automatically monitor and diagnose the state of any equipment. The system performs continuous analysis and processing of data, notifying the operator of emerging or possible problems, analyzes the operation of each component of the equipment in real time and predicts its condition and performance in the future.

According to the Russian company Praktichnaya Mekhanika, with the introduction of proactive maintenance, the time of planned shutdowns is no more than 10% of the total equipment operation time, and the average time between failures due to equipment failure increases significantly. According to statistics, direct maintenance costs for unscheduled repairs are 1.5 - 3 times higher than for scheduled ones, a third of the scheduled preventive maintenance work is superfluous, a quarter of spare parts for repairs lie in a warehouse without movement for more than two years.

Research by Emerson Process Management shows that preventive maintenance costs will be 5 times higher and on-demand service costs 15 times higher than with a proactive approach.

The main direction of improving the efficiency of the airline is to increase flight hours and reduce the cost per unit of transport products.

The application of the proactive maintenance method reduces the time of forced downtime of the aircraft for maintenance, material and human resources, which increases the profitability of the airline.

The built-in on-board information recording devices of the latest generation of aircraft allow obtaining additional data on the results of diagnosing the state and operation of aircraft functional systems outside the home airport, which increases the likelihood of determining the source of danger (failure) and reduces the need for direct equipment inspection.

On average, unplanned downtime for a typical process can cost 1-3% revenue and 3040% profit per year.

Monitoring the state of the FS allows you to carry out maintenance only of those products that require it. Consequently, the overall labor intensity of the technological process procedures is reduced, the cost of materials and the volume of spare equipment and the associated costs for its maintenance, which can be 25% of the cost, are reduced.

During the operation of the aircraft, its components and assemblies are constantly exposed to operational factors that affect their technical condition, the structural parameters of the elements change, the orderliness of the system as a whole and its functional qualities deteriorate, degrade.

The works of the theory of aging of machines Khrushchov M. M., Zaitseva A. K., Dyachkova A. K., Konvisarova D. V. do not give a complete analysis of the real actual state of the system as a whole, because do not take into account the random nature of the external change in the operating conditions of its individual parts and assemblies (patterns of deterioration in lubrication conditions over time, violations of adjustments in operation, etc.) and do not consider the operation of products as a whole.

The solution to the problem of increasing the reliability of the FS can only be obtained with an integrated approach that involves covering all stages of operation throughout the entire life cycle of the aircraft.

An analysis of the reliability of aircraft functional systems shows that most

The number of operational failures is gradual, and this is due to the increasing aging of the system products

Information about the progressive aging of systems can be obtained from considering the dynamics of some of the defining parameters, such as quantifying the mechanical wear of a structural element, fuel consumption, spring stress, increased vibration of rotating parts; technological and operating parameters (temperature

ra, load, pressure, humidity, etc.); wear particles in the lubricant, etc.

Conditions of use that lead to a deviation in the parameters of the source of failure (conditional failure), cause the destruction of the material of the system object (incipient failure), which is a direct cause of failures in operation (impending failure), and this, in turn, leads to a state of failure of the system (abrupt or catastrophic failure) as shown in Fig. 5 .

Rice. 5. Scheme of failure development

The idea of ​​proactive equipment maintenance is to ensure the maximum possible overhaul life of equipment through the use of modern technologies for detecting and suppressing sources of failures.

The basis of proactive maintenance are:

Identification and elimination of sources of recurring problems leading to a reduction in the overhaul interval of the facility;

Elimination or significant reduction of factors that adversely affect the overhaul interval or the life of the facility;

Recognition of the state of the object in order to check the absence of signs of defects that reduce the overhaul interval;

Increase the overhaul interval and the life of the facility due to the installation, adjustment and repair work in strict accordance with the technical specifications and regulations.

In fact, proactive maintenance assumes the same reactive approach as condition-based maintenance with parameter control, but such system parameters are selected as diagnostic signs, the observation of which makes it possible to control the root causes of the degradation of system stability factors. Monitoring the change in material properties in the early stages of deviation of the failure source parameter allows, through preventive maintenance of this source, to prevent

prevent further degradation of the system as a whole.

Characteristic qualitative features of the influence of various approaches to maintenance on the operation process and overhaul intervals of the object under study are illustrated in Fig. 6.

Curve 1 (CoS) corresponds to a change in the state of the object of operation during reactive maintenance (RS). Point Z corresponds to a breakdown or failure of an object or the depletion of a resource, which predetermines its replacement or repair.

Operating time

Rice. Fig. 6. Dependence of the level of the technical condition of the object on the time of operation at various

types of service:

1 - reactive maintenance (RO), 2 - status maintenance (OS),

3 - proactive maintenance (PO)

Graph 2 characterizes the operation of the facility during maintenance on condition (OS) and consists of three sections. The COO curve corresponds to a change in the parameters of the object of operation until they reach the limit value at the point

A. The horizontal section of the RR reflects the time of repair, and the vertical line of the PH - an increase in the level of the working condition of the object to the value of C1. At the same time, the time of development of subsequent failures to repair in the range from T1 to T2, T3, etc. decreases on average, and the initial level of the state after the repair no longer reaches the initial one (C1<Со), так как отказы одних агрегатов системы оказы-

have a negative impact on the performance of others.

Graph 3 characterizes the operation of the facility with proactive maintenance (PS). As noted above, this type of service is the next step in the development of the OS method, so the general form of dependence 3 is similar to graph 2. Point P corresponds to the deviation of the failure source parameter from the norm.

There is no horizontal section, because adjustment of the state of the object to the initial level Co, associated with the elimination of the root causes of failures, such as

as a rule, does not require temporary decommissioning of the facility.

This figure clearly reflects the advantages of a proactive approach to maintenance, the main of which is the absence of periods of forced downtime of maintenance facilities due to repairs. Therefore, with a certain degree of idealization, proactive maintenance is characterized by a constant, time-independent level of state C0 of an "eternal" unit, the service life of which is maintained by systematically eliminating sources of defects that lead to its premature failure.

According to independent surveys, the average operating savings achieved by applying a proactive approach are: return on investment - ten times, maintenance cost reduction - 25-30%, accident reduction - 70-75%, downtime reduction - 35-45% , increase in productivity - 20-25%.

In this regard, we can expect a significant effect from the introduction of proactive

giving an approach to the maintenance of aircraft functional systems, including an increase in their service life.

Bibliographic list

1.Doc. 9859 - AN/474. Flight Safety Management Manual [Text]. - ICAO. - 2009.

2.Doc. 9859 - AN/460. Flight Safety Management Manual [Text]. - ICAO. - 2006.

3. Hoske, M. Taking care of the “health” of equipment [Text] / M. Hoske // Control Engineering. - Russia. - July, 2006. -p.12-18.

4. Aleksandrovskaya, L. N. Modern methods of ensuring the failure-free operation of complex technical systems [Text] / L. N. Aleksandrovskaya, A. P. Afanasiev, A. A. Lisov. - M.: Logos, 2001. - 208 p.

5. Fitch, E.C. Extending Component Service Life Through Proactive Maintenance / E.C. Fitch // An FES/BarDyne Technology Transfer Publication #2. Tribolics, Inc., 1998.

PROSPECTS OF DEVELOPMENT OF METHODS OF MAINTENANCE OF COMPLEX SYSTEMS OF AIRBORNE EQUIPMENT COMPLEX

© 2012 N. V. Сhekrizhev, A. N. Koptev

Samara State Aerospace University named after academician S. P. Korolyov

(National Research University)

The paper deals with the principles of a qualitative approach to a perspective method of proactive maintenance for complex systems of aircraft on-board equipment.

Flight safety, management of risks, development offailure (refusal), proactive maintenance.

Chekryzhev Nikolai Viktorovich, Associate Professor of the Department of Aviation Equipment Operation, Samara State Aerospace University named after Academician S.P. Korolev (National Research University). E-mail: [email protected]. Research interests: control and testing of aircraft and their systems.

Koptev Anatoly Nikitovich, Doctor of Technical Sciences, Professor, Head of the Department of Aviation Equipment Operation, Samara State Aerospace University named after Academician S.P. Korolev (National Research University). E-mail: [email protected]. Research interests: control and testing of aircraft and their systems.

Nikolay ^ekrizhev, associate professor of the aircraft maintenance department, Samara State Aerospace University named after academician S. P. Korolyov (National Research University). Email: [email protected]. Area of ​​research: Control and testing of aircraft and their systems.

Anatoliy Koptev, doctor of technical sciences, professor, head of the aircraft maintenance department, Samara State Aerospace University named after academician S. P. Korolyov (National Research University). Email: [email protected]. Area of ​​research: Control and testing of aircraft and their systems.