Condition monitoring systems for machinery comprise dozens or even hundreds of vibration and temperature sensors. Designing multi-purpose sensors measuring various parameters is an urgent task in instrument making industry.
Nowadays, due to high reliability and temperature tolerance sensors made of piezoceramic materials become widely spread. The piezoceramic sensors are intended to measure force, pressure, acceleration, humidity, temperature and flowrate. But, for example, force sensors use direct piezo-effect comprising change of charge value at the opposite surfaces of a crystal caused by tensile or compressive forces.
Temperature measurement by means of piezo-crystal, as a rule, is based on anisotropy – by selecting a particular piezo-element slice orientation in relation to crystallographic axis one can change its thermal frequency response (TFR) which, generally, is a non-linear temperature function.
The paper is devoted to development of a method for temperature evaluation by means of piezoceramic vibration transducer. The paper reveals the results of development and testing of vibration/temperature piezo-sensor. Temperature measurement error within the whole vibration measurement range does not exceed ±1ºС in case when the air temperature range varies from –40ºС to +100ºС.
Kostyukov V.N., Kostyukov Al.V., Boyarnikov A.V. Multifunctional sensors made of piezoceramic materials // Dinamika sistem, mehanizmov i mashin (Dynamics of systems, mechanisms and machines). - Omsk: OmSTU, 2014. - Iss. 4. - p. 135-138.
Centrifugal pump operation in cavitation mode may cause fast destruction of running wheel, pipe lines, and additional vibration loads at machine’s structure. In that connection, automatic diagnostics of cavitation mode is vital for safety of its operation.
Today, the main method of centrifugal pump condition evaluation, including its condition in cavitation mode, is the vibration-acoustic method, comprising the analysis of vibration signal on the surface of the machinery unit. As the result of the signal analysis, a special expert system creates a set of diagnostic features by which using rules of basic logic a diagnostic expert message is issued.
The paper dwells upon centrifugal pump cavitation diagnostics using one of modern methods of non-linear dynamics - the fractal theory, which uses Hurst index, correlating with vibration signal dimensions as a diagnostic feature. The main advantage of the feature is independence from the level of analyzed signal, and, consequently, from size and power of the machinery unit.
Kostyukov V.N., Boychenko S.N. Hurst index in real-time diagnostics and monitoring of centrifugal pump operation in cavitation mode // Dinamika sistem, mehanizmov i mashin (Dynamics of systems, mechanisms and machines). - Omsk: OmSTU, 2014. - Iss. 4. - p. 132-135.
Safe resource-saving operation of machinery in production and transport industries is an urgent task.
Machinery condition monitoring ensures observability and utilization of the Technology for safe resource-saving operation and maintenance.
The paper considers the experience in condition monitoring systems operation in power and railway transport industries.
Kostyukov V.N. Vibration monitoring of production and transport facilities // Dinamika sistem, mehanizmov i mashin (Dynamics of systems, mechanisms and machines). - Omsk: OmSTU, 2014. - Iss. 4. - p. 129-132.
All major factors causing high operational costs and losses due to accidents reveal themselves in machinery operation life. Total loss directly depends on timely detection of failures and efficiency of personnel’s actions at various speeds of operation life loss due to wearing out elements of the machine.
The paper briefly describes the mechanism of machinery failure risk monitoring in real time, the development and improvement of which is the main task the DYNAMICS SPC has been performing for 20 years now. The development uses the data from the COMPACS® system for accidents prevention and machinery condition monitoring created by the DYNAMICS SPC. The non-destructive testing systems are implemented at dozens of enterprises operating hundreds of hazardous production facilities in Russia and abroad and control over 20 000 machinery units of 1700 types.
Kostyukov V.N., Kostyukov Al.V., Kostyukov A.V. Real-time monitoring of machinery operation risks // Dinamika sistem, mehanizmov i mashin (Dynamics of systems, mechanisms and machines). - Omsk: OmSTU, 2014. - Iss. 4. - p. 126-129.
Bringing together more than 20-year experience in monitoring and diagnostics of important machinery equipment of refinery, petrochemical, metallurgy, mining industries, as well as an experience in railway transport diagnostics, DYNAMICS SPC actively develops an innovative technology of rolling stock condition control on the basis of real-time monitoring – an automated system for safe resource-saving operation and maintenance of machinery – COMPACS®.
Creation and development of the COMPACS® system are aimed at increasing safety and achieving uninterrupted functioning of railway transport by means of efficient control over the condition of rolling stock and infrastructural objects by means of continuous real-time monitoring.
The paper reveals the results of developing an automated control system for safe resource-saving operation and maintenance of rolling stock equipment of a suburban railway passenger train. It features the information on key elements of the COMPACS® system and the tasks it solves.
Kostyukov V.N., Kazarin D.V., Schelkanov A.V. An automated system of safe resource-saving operation and maintenance of rolling stock equipment of a suburban railway passenger train // Dinamika sistem, mehanizmov i mashin (Dynamics of systems, mechanisms and machines). - Omsk: OmSTU, 2014. - Iss. 4. - p. 122-125
In the process of railway rolling stock operation the most crucial units, subjected to sudden failures, are critical for the whole rolling stock. These primarily include electrical and mechanical units, where troubleshooting within operational process is rather difficult.
The most effective methods of defects detection in rotary mechanical equipment are thermal and vibroacoustic ones, however the thermal method allows only to establish the fact of the unit destruction, or detect defects at a late stage of their development, while the vibroacoustic method of non-destructive testing allows to detect both incipient and developed defects.
A large number of noise components, accompanied with interaction between a wheel and a track, has lead to a conclusion that an objective vibroacoustic health monitoring within operational process of the rolling stock rotary mechanical parts is rather difficult and sometimes is even impossible.
Meanwhile, to achieve a dynamic error equal to 1% (an acceptable level for critical equipment is 0.1%) it is necessary to carry out diagnostics at intervals of not more than 2 hours, which can realized only through implementation and application of on-board health monitoring systems.
The research purpose is to determine the most informative, from vibration analysis point of view, frequency range of a vibration signal for an expert system development and the railway rolling stock condition monitoring.
Primary analysis of data has proved that vibration parameters level on a traction motor differs significantly from vibration parameters levels on other electric motors, installed on the same car. This fact has allowed to presume the traction motor malfunction.
The analysis has shown that the vibration parameters level in different frequency bands is substantially influenced by the rolling stock running speed and operating modes. It has been also established that units with different state of health are influenced in a different manner.
Discrete components of vibration acceleration envelope spectrum, corresponding to frequencies of these or those defects occurrence, are revealed in different speed modes that should be used in the expert system development.
As a result, characteristics of vibration parameters distribution in the rolling stock units within an electric multiple unit train motion in different frequency bands and speed modes have been determined, as well as impacts effect generated from variable speed and dynamic operating modes.
The research results are intended for application within development of the expert system, implemented in on-board systems for the rolling stock units condition monitoring.
Kostyukov Al.V., Tsurpal A.E., Basakin V.V. Research of vibration in railway rolling stock mechanical parts // Condition Monitoring and Machinery Failure Prevention Technologies (СМ/MFPT 2014)
The carried out studies, as well as technical analysis of defects, malfunctions and unscheduled repair of electric trains revealed that in the system of the train’s auxiliary DC circuits that most liable to failures element is an electric auxiliary converter.
The paper describes a technology of diagnosing an electric train’s DC converter using three-phase alternating current spectrum parameters.
The examples of a three-phase alternating current spectrum of a faultless converter, and a converter in a pre-accident condition are given.
Kazarin D.V., Tsurpal A.E., Ilyushin M.S. Diagnostics of electric auxiliary converter of a direct current electric train using parameters of three-phase alternating current spectrum // Dinamika sistem, mehanizmov i mashin (Dynamics of systems, mechanisms and machines). - Omsk: OmSTU, 2014. - Iss. 4. - p. 119-121
To increase diagnostic reliability providing an objective assessment of equipment’s condition is an urgent task. The paper includes the estimation of errors for wheel-motor unit axle equipment diagnostics carried out while testing wheel-pairs at various rotation frequencies.
The main diagnostic task is to recognize condition of assemblies and machines and classify them as faultless or faulty, which is related to risks of false alarm or defect skipping. Utilization of any of the diagnostic methods may lead to such errors as defect skipping or false alarm.
A defect skipped during a rolling stock operation may lead to the destruction of an assembly, and that may cause not only an expensive unscheduled repair, failures in train movement schedule, but also a hazard or an accident. False alarm may lead to additional repairs at the assemblies that do not require any maintenance, which can make the condition even worse, thus, reducing the operational readiness of the rolling stock.
The paper is aimed at increasing reliability of diagnostics with minimum costs of testing.
Zaytsev A.V., Teterin A.O. Method applied for increasing reliability of diagnostics of axle equipment of wheel-motor units in electric trains // Dinamika sistem, mehanizmov i mashin (Dynamics of systems, mechanisms and machines). - Omsk: OmSTU, 2014. - Iss. 4. - p. 115-118
To improve the existing methods of operation-based condition diagnostics of rolling bearings is an urgent task.
The most efficient method for detection of both nucleating and developed defects of rolling bearings is the vibration-acoustic method of non-destructive testing. Operation of rolling bearings is closely related to changes in wide range of both rotation frequencies and radial/axial loads. To provide an adequate assessment of rolling bearings condition using vibration-acoustic method one needs to know what impact various factors have on vibration rates.
The paper considers a method of conducting an experimental study, as well as an experimental stand evaluating the dependency between rolling bearing parameters and rotation frequencies, radial/axial loads.
Basakin V.V., Kudryavtseva I.S., Zaytsev A.V., Teterin A.O. Method of experimental research on bearing vibration // Dinamika sistem, mehanizmov i mashin (Dynamics of systems, mechanisms and machines). - Omsk: OmSTU, 2014. - Iss. 4. - p. 112-115
The paper dwells upon the basic concepts of choosing condition monitoring system for pump and compressor units of refinery production of various categories of hazard (according to GOST R 53563-2009), increasing units’ run-to-failure time and accident-free resource-saving operation.
The paper describes basic principles of monitoring and real-time diagnostics systems building, specifications of the system’s software and hardware based on selection and rationalization of classification factors according to GOST R 53564-2009. The correlation between failure skipping risk and system’s class is shown.
The main goal of equipping hazardous production facilities with a comprehensive monitoring system is to ensure safe resource-saving operation of machinery by means of preliminary control actions providing necessary stability margin, high-quality rates of its functioning and technological, ecological and economical safety.
Kostyukov V.N., Naumenko A.P., Tkachenko A.A. Concept of selection and rationalization of pumps condition monitoring system specifications // Increasing pump units’ reliability. Analysis of existing pump systems. Basic concepts of design and choice of pump units for refinery and petrochemical companies: from the expert meeting. – Moscow: Council of Chief Mechanical Engineers, 2014. - p. 81-101.