CALCULATION METHOD APPLIED TO ASSESS OF OPERATIONAL RELIABILITY PARAMETERS OF ELECTRIC CENTRIFUGAL PUMPING UNITS BASED ON STATISTICAL INFORMATION

The article discusses the method of preliminary analysis of the reliability of the design of peat machines (PM) at the design stage. For the designed TM, it is possible to assess the reliability using generalized statistical data on similar peat machines, but significant errors arise that do not allow predicting the technical condition of the equipment under development with the required accuracy. The proposed technique makes it possible to evaluate the developed design of the machine in terms of reliability based on the analysis of the operation of similar units of existing PM. For this, the existing peats machines are divided into separate mechanisms, for which there are statistics on failure parameters. The division of the designed machines is carried out in a similar way; while in order to obtain the necessary reliability parameters, it is proposed to use the coefficient calculation method, taking into account the presence in the developed PM design of the number of the most critical parts and assemblies. Thus, the use of data from the operation of existing PM makes it possible to improve the quality of predicting changes in the reliability parameters of the machines being developed, and as a result, during their operation, a decrease in the number of downtime due to difficult-to-predict failures is achieved, which makes it possible to increase the seasonal productivity of PM.

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Study on Failure Process Deterioration and its Amelioration of Mine Ventilation System

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.634-638.3502 ◽

2013 ◽

Vol 634-638 ◽

pp. 3502-3505

Author(s):

Hong De Wang

Keyword(s):

Failure Process ◽

Ventilation System ◽

Operation Time ◽

Mine Ventilation ◽

Operational Reliability ◽

System Failure ◽

Mean Time Between Failures ◽

Reliability Parameters ◽

Failure Evolution ◽

Process Characteristic

Mine ventilation system is a repairable system, with the characters of time-varied and randomness. It made us encounter some difficulties when we discussed the system failure evolution process and its operational reliability, as well as when we sought the system reliability parameters developing trends following with ventilation system operation time variation and air adjustment. Firstly, according to the reliability theory, the failure process characteristic values, which affect the ventilation system, were defined. And then, by mean of the analysis of the failure process deterioration of mine ventilation system, the deterioration and its amelioration discriminants are given basing on two parameters’ Weibull process. Finally, on the basis of adaptive neural network technology, the ventilation system failure processes were simulated, the failure process characteristic parameters were determined, and the failure curves were drawn accordingly. The results show that the failure process of the experiment mine ventilation system is a Non-homogeneous Poisson Process; the mean time between failures of the ventilation system is between 160h and 170h; the failure ratio curves present the trends of concave or convex variation when the system failure process deterioration or amelioration.

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RESEARCH CONCERNING THE SIMULATION OF THE OPERATION OF CONVENTIONAL SUCKER ROD PUMPING UNITS

Romanian Journal of Petroleum & Gas Technology ◽

10.51865/jpgt.2021.02.04 ◽

2021 ◽

Vol 2(73) (2) ◽

pp. 33-39

Author(s):

Georgeta Toma ◽

Keyword(s):

Computer Program ◽

Calculation Method ◽

Operating Parameters ◽

Motor Torque ◽

Sucker Rod ◽

Pumping Unit ◽

Pumping Units

In the paper is presented a method for obtaining the variation during a cinematic cycle of the motor torque at the crankshaft in the case of the conventional sucker rod pumping units. The calculation method has been transposed into a computer program which allows establishing the influence of different constructive and operating parameters of the pumping units on the variation of the motor torque at the crankshaft. Finally, a series of results of the simulations performed in the case of a C-640D-305-120 pumping unit are presented.

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Stress Strain State of Steam Turbine Components under Plastic Deformation

Nuclear and Radiation Safety ◽

10.32918/nrs.2020.4(88).02 ◽

2020 ◽

pp. 14-17

Author(s):

I. Palkov ◽

S. Palkov

Keyword(s):

Plastic Deformation ◽

Steam Turbine ◽

Calculation Method ◽

Power Plants ◽

Turbine Unit ◽

Strain State ◽

Operational Reliability ◽

Stress Strain ◽

Stress Strain State ◽

Pressure Cylinder

Reliable operation of secondary equipment of PWR nuclear power plants is an integral part of nuclear and radiation safety of the entire NPP unit. The problem of stress strain state of steam turbine structural components under plastic deformation is considered. The theory of elastic-plastic deformations is used to solve the problem along with the finite element method. The paper presents the results of computer assessment of stress strain state of locking joint of working blades of the first stage of a intermediate-pressure cylinder (IPC) and high-pressure cylinder (HPC) body of a steam turbine, which makes it possible to characterize the degree of relaxation and stress redistribution in the structure in comparison with obtained earlier results. It is provided that the use of the presented calculation method in designing new structures of steam turbine components operating in the area of high thermal and power loads, taking into account the contact interaction of components, as well as different mechanical and physical properties of materials, and their changes depending on operating temperature, at this stage of software development allows one to identify problem areas in the design and prevent further breakdowns in the turbine. Based on the comparison of operational data of the developed design solutions and calculation assessment, it is proved that the chosen calculation method can significantly increase the operational reliability not only of the turbine unit but also the nuclear unit as a whole, as well as reduce economic costs caused by turbine unit downtime during maintenance.

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DETERMINATION THE PERIOD OF GUARANTEED TROUBLE-FREE OPERATION OF THE HYDRAULIC SCHEMES BASED ON THE OPERATIONAL RELIABILITY INDICATORS OF PUMPING UNITS

Construction and industrial safety ◽

10.37279/2413-1873-2021-21-115-134 ◽

2021 ◽

pp. 115-134

Author(s):

I. V. Nikolenko ◽

E. E. Kotovskaya ◽

A. O. Budchany

Keyword(s):

Data Processing ◽

Failure Rate ◽

Statistical Data ◽

Operational Reliability ◽

Reliability Indicators ◽

Pumping Stations ◽

Artesian Water ◽

The Republic ◽

Pumping Equipment ◽

Pumping Units

The article presents the values of the failure rate for modern types of pumps of four groups: submersible, designed for drainage and wastewater drainage; domestic; cantilever; submersible - for artesian water intake based on statistical data processing on their operation. The obtained values of the failure rate allow us to evaluate the reliability indicators of hydraulic circuits that use various types of pumping equipment. The article analyzes the failures of pumping equipment with their detailed description and presentation of practical photos accumulated at a specialized enterprise, whose activities are aimed at designing pumping stations, supply, installation and maintenance of pumping equipment on the territory of the Republic of Crimea.

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The risk analysis at working with a chainsaw

Scientific Bulletin of UNFU ◽

10.36930/40291016 ◽

2019 ◽

Vol 29 (10) ◽

pp. 82-84

Author(s):

Jan Kovach ◽

Pavol Tiavoda ◽

Jozef Krilek

Keyword(s):

Risk Analysis ◽

Failure Modes ◽

Negative Impact ◽

High Reliability ◽

Operational Reliability ◽

Human Potential ◽

Operational Conditions ◽

Wood Processing ◽

Reliability Parameters ◽

Fmea Method

Forestry in Slovakia has recently got very fast tendency of research in all levels. The introduction of complex machines and equipment, the application of new advanced technologies, the tendency to decrease energy consumption, material difficulty of products, requirements on high reliability of machines and automation in operation impose the necessity for the search of theoretical basics for wood production processes and utilization of new developing forest and wood processing techniques. The work with a chain saw is risky and has negative impact on the health of workers. It has been clear from recent findings. The limitation of these impacts has influence on technical, technological and organizational actions serving as preventive ones. That is the reason why the famous chain saw producers established different technical supports which have the influence on decrease of vibrations and noise. It is necessary to realize several actions within the maintenance of chain saws to fulfil the goals of a technical action. The paper deals with risk analysis by usage Failure Modes and Effects Analysis (FMEA), which was implemented on STIHL motor chainsaw. We identified the potential failures, then we allocated to the value of occurrence, significance and detectability in the process and we also calculated the risk priority number (RPN). Application of the FMEA method allows flexibility in the case of unexpected situations and optimization of human potential abilities. FMEA is a tool preventing outages operational reliability and preventive tool for ensuring the maintenance of facilities. There are several methods of information processing regarding to reliability parameters, but some of them are very difficult and in standard operational conditions are not usable. The method of information analysis mentioned below is simple but precise enough for implementation in real working conditions.

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ON DEVELOPMENT OF AVIATION EQUIPMENT’SRELIABILITY MODELS (ON THE EXAMPLE OF HELICOPTERS)

Наукові праці Державного науково-дослідного інституту випробувань і сертифікації озброєння та військової техніки ◽

10.37701/dndivsovt.4.2020.02 ◽

2020 ◽

pp. 8-16

Author(s):

A. Bursala ◽

O. Tcherednikov ◽

V. Golub ◽

Y. Trygub

Keyword(s):

Statistical Models ◽

Operational Reliability ◽

Technical Condition ◽

Statistical Information ◽

Current Level ◽

Flight Safety ◽

Combined Operations ◽

Military Aviation ◽

Engine System ◽

Mathematical Processing

On the example of helicopters, the topical issues of systematization and mathematical processing of statistical information taking from fault log sheetsto assess the level of reliability and flight safety of state aviation equipment are considered. The reliability of all helicopter systems must meet the pressing needs of defense capabilities and support the capabilities of the state aviation of Ukraine to carry out combat missions at the current level. Improving preparedness for assigned tasks will facilitate participation in combined operations with peacekeeping and NATO forces. The considered model of the system of aviation equipment on the example of helicopters consists of interdependent, jointly functioning, united by a single purpose of five subsystems of the corresponding type of specialty: “helicopter and engine”, “aircraft armament”,“aircraftequipment”, “avionics equipment”,“navigation and target acquisition system”. Realization and methodical approaches to the development of complex failuremodels of the elements of “helicopter and engine” system by types of helicopters are substantiated. The paper proposes to address on the example of helicopters the lines of approach the problem of assessing the real level of operational reliability and flight safety of aircraft to maintain their serviceable condition. When putting military aviation assets into operation according to the technical condition, using statistical models of reliability and flight safety, the important task of increasing resource indicators is solved, which requires improving the system of collecting, processing and analyzing information from fault log sheets.

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