scholarly journals Wavelet Transforms of Diagnosable Signals from Ship Power Complexes in a MATLAB Environment

Designs ◽  
2020 ◽  
Vol 4 (4) ◽  
pp. 52
Author(s):  
Vladimir Sakharov ◽  
Sergei Chernyi ◽  
Sergey Saburov ◽  
Aleksandr Chertkov

The use of digital technologies in the systems of diagnostics and monitoring of units of a ship’s propulsion plant can significantly increase the efficiency and quality of assessing the technical condition of operated objects in the online mode as well as expand the class of practical problems to be solved. Digital processing of signals of complex configuration at a qualitatively new level is an indispensable condition for a critical improvement in the course of processing the current values of diagnosable parameters, increasing the reliability and trouble-free performance of a ship’s technical equipment during operation. A method of approximation has been discussed in the paper. Moreover, the paper provides an algorithm for analyzing the signal of the indicator diagram of a marine diesel engine, the spectrum of which contains high-frequency components and short-term pulses indicating deviations from the normal operating mode, the assessment of which is practically impossible with the traditionally applied methods of spectral analysis of signals. The approximation method is based on the use of wavelet analysis, which makes it possible to deeply explore such modes. Examples of using wavelet analysis to approximate one-dimensional signals of elements and systems of a ship’s power complexes are given.

2018 ◽  
Vol 19 (6) ◽  
pp. 1068-1073
Author(s):  
Daria Kubowicz

Intermodal transportation is becoming more and more willingly used in the goods supply chain in view of its specific, flexible characteristics. In Poland, intermodal transportation is based primarily on land-sea and rail-road transportation, using mostly containers. The most frequently used containers in 2017 were the 40-feet containers which accounted for over 57% of all containers transported. Contribution of the railway transportation in intermodal transportation is increasing every year. Despite the slow growth, both, planned as well as already carried out investments in intermodal terminals, indicate continuous growing pattern. Many operators strive to improve the technical condition of nodal and linear infrastructure that leads to raising the quality of services provided. Large number of investments aimed at improving the functioning of intermodal transportation in Poland are made by PKP PLK S.A which is the conductor rail operator. The most important of them include improvement of the railway lines technical condition of the major routes, that would increase the average operational speed. The largest intermodal terminal in Poland is the DCT Gdańsk located in the Northern Port in Gdańsk. The annual transshipment ability of the terminal after the investments made is set at 3 million TEU. The terminal is connected with the hinterland by road and rail connections. Due to high quality technical equipment it is able to serve up to 9 trains a day which adds up to almost 300 trains per month. It provides railway connection to almost all overland intermodal terminals in the country. DCT Gdańsk gladly invests in development of the railway transportation and endeavour to achieve rail system development not only at the terminal, but also throughout Poland.


2020 ◽  
pp. 43-50
Author(s):  
A.S. Komshin ◽  
K.G. Potapov ◽  
V.I. Pronyakin ◽  
A.B. Syritskii

The paper presents an alternative approach to metrological support and assessment of the technical condition of rolling bearings in operation. The analysis of existing approaches, including methods of vibration diagnostics, envelope analysis, wavelet analysis, etc. Considers the possibility of applying a phase-chronometric method for support on the basis of neurodiagnostics bearing life cycle on the basis of the unified format of measurement information. The possibility of diagnosing a rolling bearing when analyzing measurement information from the shaft and separator was evaluated.


Crystals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 182
Author(s):  
Karel Osička ◽  
Josef Chladil

This article discusses the issue of hardened steel machining. Many components in the engineering industry use hardening as the final heat treatment. These components usually occupy a significant position in a given assembly unit. They guarantee the correct operation of the entire technical equipment in total cooperation with other components. The quality of these components depends on the integrity of their surface. The production of these parts is usually carried out by traditional technological procedures. Clearly, an example of such a technology is grinding. However, this article discusses the application of other finishing technologies using a tool material made of cubic boron nitride (CBN). The technology used is finishing turning with subsequent tumbling technology. The subject of the evaluation is the integrity of the surface. In this part of the experiments, there are mainly individual parameters of surface roughness. Compared components are bearing rings, in this case the inner surface of the housing ring.


Author(s):  
A.V. Golenishev ◽  
A.V. Nadezkin ◽  
M.E. Starchenko

Рассматриваются подходы по определению пороговых значений концентрации продуктов износа в отработанном цилиндровом масле, характеризующие переход объекта диагностирования судового крейцкопфного дизеля из одного технического состояния в другое. Показано, что существующие методики не учитывают индивидуальные особенности и техническое состояние деталей цилиндропоршневой группы. Предложено для решения задачи их трибодиагностики использовать разработанную имитационную модель, позволяющую провести моделирование процесса изнашивания цилиндровой втулки и поршневых колец судового дизеля и на основании полученных расчетов определить концентрацию продуктов износа поступивших в отработанное цилиндровое масло при различной скорости изнашивания трущихся деталей. Данные о фактической концентрации продуктов износа в отработанном цилиндровом масле в дальнейшем соотносятся с результатами моделирования, что позволяет оценить техническое состояние деталей цилиндропоршневой группы двигателя. Представлены результаты моделирования по определению пороговых значений концентрации продуктов износа в отработанном цилиндровом масле, характеризующее переход судового дизеля из исправного в несправное техническое состояние. Даны практические рекомендации по выбору пороговых значений содержания продуктов износа в отработанном цилиндровом масле для различных типов судовых крейцкопфных дизелей и условий их эксплуатации.The article examines approaches to determine the threshold values of the concentration of wear debris in used cylinder oil that characterize the transition of a ship crosshead diesel engine unit under test from one technical condition to another. It is shown that the existing methods do not take into account the individual characteristics and technical condition of the parts of the cylinder-piston group. To solve the problem of tribodiagnostics, it is proposed to use the developed simulation model, which allows modeling the wear process of the cylinder bushing and piston rings of a marine diesel engine and, based on the obtained results, determining the concentration of wear products issued in the used cylinder oil at different wear rates of the moving parts. The data on the actual concentration of wear products in the used cylinder oil are subsequently correlated with the simulation model results, which makes it possible to evaluate the technical condition of the parts of the engine cylinder-piston group. The article presents the results of modeling of threshold values determination of the concentration of wear products in used cylinder oil, that measure the transition of a marine diesel engine from a working condition to a malfunctioning technical condition. Practical recommendations are given on choosing threshold values for the concentration of wear products in used cylinder oil for various types of marine crosshead diesel engines and their operating conditions.


2021 ◽  
Vol 12 (2) ◽  
pp. 112-121
Author(s):  
Oleksandr Khrulev ◽  
◽  
Olexii Saraiev ◽  
Iryna Saraieva ◽  
◽  
...  

The analysis of the crankshaft bearing condition of the automotive internal combustion engines in the case of insufficiency and breakage of oil supply to them is carried out. It is noted that this fault is one of the most common causes of damage to rubbing pairs in operation. At the same time, the different groups of bearings are often damaged, which cannot be explained within the framework of existing models of plain bearing lubrication. The objective of the work is to develop a mathematical model of oil supply to connecting rod bearings in emergency mode, taking into account the characteristic features of the bearing design. The model also, depending on the nature of the damage, should help to determine and explain the causes of bearing failures if they occur in different modes when operating conditions are broken. A computational model has been developed that makes it possible to assess the effect of design differences in the features of oil supply and the action of the centrifugal forces during crankshaft rotation on the oil column in the lubrication hole where oil is supplied to the conrod bearing. Calculations of the change in time of the oil supply pressure to the connecting rod bearings for the various designs of the crankshaft lubrication holes have been performed. It is shown that, depending on the operating mode of the engine and its design, the oil pressure in front of the connecting rod bearings does not disappear immediately after oil supply failure to crankshaft. Moreover, the lower the crankshaft speed is, the longer the lubrication of the conrod bearings will continue. The calculation results are confirmed by the data of the expert studies of the engine technical condition, in which the crankshaft was wedged in the damaged main bearings was found in the absence of serious damage to the connecting rod ones. It has been found that such features of the damage correspond to an rapid breakage of the oil supply to the crankshaft in the case of such operational damage as the oil pump and pressure reducing valve failure, the oil filter seal and oil pan destruction, etc. The developed model explains the difference in lubrication conditions and in the damage feature to the main and connecting rod bearings in the emergency cases of the oil supply breakage, which are observed during operation, and helps to clarify the failure causes. This makes it possible to use the model and the obtained data when providing auto technical expert studies of the failure causes of automobile internal combustion engines This makes it possible to use the model and the obtained data when providing auto technical expert studies of the failure causes of automobile internal combustion engines when the operating conditions are broken.


2018 ◽  
Vol 1 (1) ◽  
pp. 721-728
Author(s):  
Marek Łutowicz

Abstract Due to the limited scope of the diagnostic equipment on the ship, the technical condition of the engine is based on the measurement of pressure and temperature at the available measuring points. Usually it is the exhaust temperature at the outlet of individual cylinders, supercharging pressure, oil temperature and cooling water temperature. Sometimes the bearing temperature and turbocharger speed are also measured. Normally, if the engine is adapted to this, the maximum combustion pressure is measured periodically although distorted through the channels with the indicator valves. The paper presents examples of the exploitation of marine diesel engines, where there is a discrepancy between the actual technical state of the engine and the technical state of the engine based on the traditional diagnostic method based on a limited set of available parameters. These discrepancies resulted, inter alia, from the regular fuel injection timing and fuel dose adjustment, so that the measured parameters were adequate to the actual load of the engine. This adjustment is justified, but leads to masking engine components wear symptoms. In this situation, it can only be stated that the state of the fuel injection equipment is suitable for the current technical state of the some engine components and does not provide a sufficient basis for the extension of the repair interval.


10.5219/1147 ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 706-712 ◽  
Author(s):  
Kulyash Meiramkulova ◽  
Mikhail Zhumagulov ◽  
Gulnur Saspugayeva ◽  
Zhanar Jakupova ◽  
Мaral Mussimkhan

With the interest to reuse and recycle the wastewater for technological use, this project aims to test the treatment of wastewater from poultry slaughterhouse industry from three main sections of the poultry slaughtering process, defeathering, eviscerating and cooling processes. The samples for the project were obtained from Izhevskoe a Kazakhstani company. The technology used is a combination of electrocoagulation, ultrafiltration, and photochemical system and its goal is to provide treated water that can be re-utilized in the poultry industry for sterilization of technical equipment without contaminating and affecting the quality of the poultry products. The treatment of wastewater samples lasted in total for 40 min. From the results, it was found that indicators such as BOD, COD, and phosphates had removal efficiency of almost 100%, while the microbiological colonies were all eradicated from then wastewater making the treated water microbes free. Hence, proving this system to be effective for the treatment of poultry slaughterhouse wastewater and safe for technological reutilization.


2011 ◽  
Vol 143-144 ◽  
pp. 613-617
Author(s):  
Shuang Xi Jing ◽  
Yong Chang ◽  
Jun Fa Leng

Harmonic wavelet function, with the strict box-shaped characteristic of spectrum, has strong ability of identifying signal in frequency domain, and can extract weak components form vibration signals in frequency domain. Using harmonic wavelet analysis method, the selected frequency region and other frequency components of vibration signal of mine ventilator were decomposed into independent frequency bands without any over-lapping or leaking. Simulation and diagnosis example show that this method has good fault diagnosis effect, and the ventilator fault is diagnosed successfully.


Author(s):  
Olha SAKNO ◽  
Ievgen MEDVEDIEV ◽  
Tatiana KOLESNIKOVA

A contemporary road vehicle (RV) is a rather complex system, consisting of a large number of subsystems, assemblies, units, and elements (parts). While operating, an RV interacts with the environment, and its elements interact with each other. Consequently, the properties (parameters) of these elements change in the process - hardness, roughness, size, relative position, gapping, etc. A partial solution to the presented problems can be the search for a technique for assessing the RV technical condition by a generalised criterion, which is quite sensitive to changes in the technical state. One of these criteria may be fuel consumption in litres per 100 kilometres. This paper investigates the possibilities of using the fuel consumption indicator as a criterion for assessing the technical condition of the vehicle and the vehicle maintenance and repair technologies have been generalised to obtain a given technical solution. Thus, the possibility of using the fuel consumption indicator as a criterion for assessing the technical condition of the vehicles was explored using the Volkswagen Touran 1.9 TDI operating in urban conditions using a driving cycle. A clear correlation between the fuel consumption and the service lifetime of the vehicle has been established; therefore, it depends on the frequency and quality of the maintenance and repair (MR). The vehicle MR technology has been generalised to obtain a specified technical solution. The process of creating an RV MR Technology model is implemented based on an iterative approach (repetition) with the possibility to specify their features.


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