The paper deals with the challenges of the machinery vibroacoustic signal modeling. The purpose of this paper is to form a phenomenological model for the structure of vibroacoustic oscillations and signals appeared in case of malfunctions and defects. It presents particular structural models for vibroacoustic signals of some reciprocating machine malfunctions. Mathematical description of the vibroacoustic signal reveals the informative parameters of the malfunction diagnostic signs. The model enables us to define in detail the informative vibroacoustic signal parameters. The model also allows us to select the diagnostic signs of the given malfunctions and defects in certain machine parts and components. At the same time, it is considered that the signal is received in certain points on the machine taking into account the excitation sources, conditioning channel and propagation of the vibroacoustic oscillations. The model has been constructed considering the presence and interaction of the three main sources of excitation of the asset vibroacoustic oscillations, which are identified by the types of excited oscillations. It is assumed that there are damped natural, undamped induced, random broadband and narrowband vibrations. The parameters of the vibroacoustic signal structural model also take into account the properties of converting the vibroacoustic oscillation to the vibroacoustic signal by means of a piezoelectric sensor. The model shows that the vibroacoustic signal has not only the components from each source, but their mutually modulated components. We developed partial models for mechanisms of structuring the vibroacoustic signal appeared in case of malfunctions and defects in rotating parts and couplings, machine shaft and drive shaft misalignment, increased clearances and other defects and failures of the rotating and reciprocating parts and components. The proposed phenomenological structural models of the vibroacoustic signals appeared in case of malfunctions of reciprocating machines show that for the diagnostic purposes it is necessary to analyze vibroacoustic signals either in the time domain according to the cyclogram of the reciprocating machine operation or in the envelope spectrum at characteristic frequencies or the noise component. In the event of defects and malfunctions in the centrifugal rotating parts and components, there are excited the vibroacoustic signals, which are advisable to analyze in the direct spectrum or in the spectrum of the noise component envelope. The proposed models enable us to select and form scientifically grounded systems of the machine failure diagnostic signs.
Kostyukov Al.V., Naumenko A.P., Boychenko S.N. Generic structural model of machinery vibroacoustic signal // AIP Conference Proceedings 2007, 050008 (2018); doi: 10.1063/1.5051952
Condition monitoring and diagnostics of rotating machines, such as pumps, compressors, fans is the most efficient policy to ensure safety and good performance of petrochemical productions. The most common type of drives in rotating machines is electric motors, mostly, induction ones. Despite their high reliability level they also require condition control for both mechanical and electrical parts, because a fault of a drive’s electric motor may lead to an emergency shutdown of the unit. When the controlled machinery is located in hazardous areas, it means that there are special conditions for diagnostic methods and means to be applied. At the same time, using remote diagnostic methods often helps to avoid such restrictions. One of the efficient control methods for isolation condition – including isolation of stators in induction motors is a partial discharge method. The authors suggest their own method of the remote method practice outside the hazardous areas. The data collected in the course of the research show that the remote monitoring of partial discharge parameters is an efficient way of diagnostics of any destructive elements in isolation and monitoring over their development. Further research done by the authors will allow defining and improving the algorithms used for automatic diagnostics of rotating machinery drive isolation.
Kostyukov Al.V., Boychenko S.N., Burda E.A. Condition monitoring and diagnostics of drive isolation in rotating machinery of petrochemical facilities by partial discharge method // AIP Conference Proceedings 2007, 050009 (2018); doi: 10.1063/1.5051953
Technogenic safety is a foundation of the efficient operation of refineries and petrochemical plants. Larger and more complex hazardous productions of refineries make it vital to increase the reliability and safety along with operational efficiency of productions. Given the maturity of the industry and market conditions, the struggle for margins and product improvement are the main priorities of refineries of such leading companies in the industry as PAO Gazpromneft. That is why the strategy of boosting operational efficiency by increasing energy performance and operational readiness, and reduction of production losses takes a special place among the strategic priorities of PAO Gazpromneft. Today the company is implementing several big projects on building a single digital platform for managing the efficiency of the value chain based on the analysis of process-related data coming from the APCS of its subsidiaries, including the introduction of condition monitoring systems. One of the main tasks aimed at increasing safety and reliability is early detection, monitoring of development, and timely elimination of malfunctions and defects of machinery operating simultaneously at production facilities with a maximum potential residual life.
Egizaryan A.M., Abrashenkov P.A., Nakonechny N.I., Kostyukov A.V., Sinitsyn A.A. Safe resource-saving operation, strategy of increasing technogenic safety and operational efficiency of Gazpromneft-Moscow Refinery // Neftepererabotka i neftekhimiya. - No. 5-2018. p. 34-39
The research’s subject is the problems of modeling vibration acoustic signals of machines and mechanisms. The main objective is to create a phenomenological model of the structure of VA oscillations and signals during the occurrence of defects and malfunctions. There are particular models for VA structures of several malfunctions of piston machines.
Kostyukov Al.V., Naumenko A.P., Boychenko S.N. Generalized structural model of a vibration-acoustic signal of piston machines // Technique and technology of petrochemical and oil and gas production: materials of the 8th international scientific and technical conference (Omsk, February 26 - March 2, 2018). - Omsk: Publishing house of OmSTU, 2018. - p.202-203
As a rule, production facilities of industrial companies share the same process in which separate units or groups of machinery perform tasks of the same type or serve the main process. A great share of such machinery is taken by air coolers; vibroacoustic diagnostics is widely used for their condition assessment.
Kostyukov Al.V., Kazarin D.V., Basakin V.V. Condition assessment for modular machines linked by uniform operating conditions // Technique and technology of petrochemical and oil and gas production: materials of the 8th international scientific and technical conference (Omsk, February 26 - March 2, 2018). - Omsk: Publishing house of OmSTU, 2018 .- p. 198-199
Currently, asynchronous electric drives are the most common for machinery at petrochemical facilities. To ensure their safe and steady operation it is required to perform monitoring and diagnostics of their condition, and condition of their insulation. In this case, it is advisable to monitor the condition of the power supply circuits as a whole, since the failure of the cable line (CL) or the supply cell will also entail a shutdown of the machinery unit. The authors consider it obvious that such issues are highly important.Currently, asynchronous electric drives are the most common for machinery at petrochemical facilities. To ensure their safe and steady operation it is required to perform monitoring and diagnostics of their condition, and condition of their insulation. In this case, it is advisable to monitor the condition of the power supply circuits as a whole, since the failure of the cable line (CL) or the supply cell will also entail a shutdown of the machinery unit. The authors consider it obvious that such issues are highly important.
Kostyukov Al.V., Boychenko S.N., Burda E.A. Condition Monitoring of Drive Insulation in Machinery at Petrochemical Facilities Based on Partial Discharge Method // Technique and technology of petrochemical and oil and gas production: proceedings of the 8th international scientific and technical conference (Omsk, February 26 - March 2, 2018). - Omsk: Publishing house of OmSTU, 2018 . p. 198
Operation of a turbine unit causes mechano-caloric processes deteriorating state of shafting parts which increases the risk of accidents and emergencies. Common types of accidents in the power industry in Russia and abroad are the ones related to the deterioration of rotors of a generator and exciter, including the one happening twice in 2013–2014 when there were partial and full deteriorations of half-coupling bolts of the exciter’s armature of a 1000 MW turbine unit. In 2014–2015 several 250 MW turbines bolt connecting high and medium pressure rotors deteriorated soon after the assembly. It should be noted, that some parts can work in similar operating conditions 5-10 years or more, while others degrade in a few months. This is also true for half-coupling bolts. Such a wide range in the wear-off is due to two crucial factors: a)variations of material properties may be caused by a 100% variation of operational characteristics; b) variations of technical deviations due to human factors during assembly may decrease operation life substantially.
Kumenko A.I., Timin A.V. Improved engineering methods of a rotor’s bolt connection state evaluation using multiple-factor analysis // Proceedings of the IX International Scientific and Technical Conference. - Moscow: OAO "VTI", 2017. - p.136-146
The paper analyses ISO standards and Russian Standards serving the same purpose, including:
• ISO 13373-3:2015 (GOST ISO 13373-3–2016). Condition monitoring and diagnostics of machines. Vibration condition monitoring. Part 3. Guidelines for vibration diagnosis;
• ISO 13373-4:2016. Condition monitoring and diagnostics of machines – Vibration condition monitoring – Part 4: Diagnostic techniques for gas and steam turbines with fluid-film bearings (In that case, there is no Russian analog, since the ISO is not approved yet).
Kumenko A.I., Kuzminykh N.Yu ISO Standards and phenomena of “oil whip” and “oil whirl” in rotary system operation // Proceedings of the IX International Scientific and Technical Conference. - Moscow: OAO "VTI", 2017. - p.73-82
The paper gives preliminary results of experimental research aimed at two tasks:
check-up of methods for diagnostics of supports misalignment by data on pivot journal floating-up measured by shaft sensors;
determining generalized sensitivities measured on the shaft in the frequency range from 0 to the operational frequency and necessary for improving the methodology of monitoring and diagnostics of residual imbalances in shafting.
Kumenko A.I., Timin A.V., Kuzminykh N.Yu. Experimental check-up of methods for diagnostics of misalignment and imbalance of rotary bench // Proceedings of the IX International Scientific and Technical Conference. - Moscow: OAO "VTI", 2017. - p.43-52
Today vibration diagnostics is one of the basic methods used in the manufacturing and maintenance of electric motors in order to diagnose their condition by vibration parameters of bearing units. At the same time, such motors may have specific defects of the electromagnetic systems, such as defects of laminations and stator windings, rotor squirrel cage, and others. Those defects can be found by vibration diagnostic methods, but it’s usually more difficult to localize and classify them, since the vibration signals may reflect processes occurring in windings of different stages of the stator, its laminations, and rotor’s conducting system. Method of partial discharges can increase the accuracy of the diagnostics, since various defects of the electro-magnetic system have their own special parametric numbers of partial discharges, and that allows determining the stage of the stator winding in which the defect is developing and its type. The combined usage of vibration diagnostic and partial discharge methods improves the quality of asynchronous motor monitoring and provides a better assessment of changes in their condition in operation.
Kostyukov A.V., Shchelkanov A.V., Burda E.A. Quality control of electric motor maintenance by vibration diagnostics and partial discharge methods // Omsk State Transport University. Omsk, 2017.217 - p. 169-175