Wyniki wyszukiwania - BazTech

1

Modelowanie i wyznaczanie charakterystyk mocy układu napędowego statku wypornościowego ze śrubą o stałym skoku

Pawletko R., Polanowski S.

Zeszyty Naukowe Akademii Morskiej w Gdyni

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2015

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nr 91

122--131

PL

W artykule scharakteryzowano problem wyznaczenia charakterystyk napędowych mocy statku ze śrubą o stałym skoku. W celu sformułowania modeli charakterystyk mocy wykorzystano w pierwszej kolejności znane aspekty fizyczne, w następnej zaś – metody statystyczne. Do weryfikacji modeli wykorzystano dostępne w literaturze przedmiotu wyniki badań układu napędowego statku m/s „Garnuszewski”. W sumie wyłoniono trzy dające zbieżne, praktycznie równe, wyniki aproksymacji danych pomiarowych mocy. Dokonano analizy odchyleń wyników pomiarów od modeli, w wyniku czego jeden punkt ze zbioru pierwotnych danych został odrzucony. Analiza charakterystyk mocy na uwięzi wyznaczonych drogą ekstrapolacji pokazała, że przebieg tej charakterystyki dla jednego z modeli wielomianowych znacznie odbiega od pozostałych dwóch charakterystyk, dając znacznie niższe wartości, co może świadczyć, że ta charakterystyka powinna być odrzucona.

EN

The paper characterized the problem of finding propulsion characteristics of the propulsion system with a fixed pitch propeller. For this objective, statistical methods and the physical aspects of the construction of adequate models characteristics were used. Test results of propulsion system of vessel MS Garnuszewski were used for models verification. In total, five statistically comparable models of torque characteristics were developed, of which three models produce consistent results of tethered torque characteristics, obtained by extrapolation. It has been shown that the other characteristics: power characteristics, characteristics of specific energy consumption per nautical mile should be determined with definitional formulas after determining torque characteristics. Put attention to the need for analysis of deviations of measurement points on the model and the removal of excessive deflecting points.

2

Analysing applicability of selected methods to smooth indicator diagrams of marine medium-speed engine

Pawletko R.

Polish Maritime Research

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2015

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nr 2

55--61

EN

The article analyses the applicability of selected smoothing methods to smooth indicator diagram curves and to filter disturbances. An intermediate goal of the study was an attempt to extract disturbances recorded during pressure curve smoothing, which are believed to be a source of important diagnostic information. Within the framework of the reported analysis, a comparison was made between the moving average method, the Savitzky-Golay filter, and the frequency filtration method. The research was performed on a marine medium-speed engine Sulzer 3Al 25/30, which has a relatively long indicator passage.

3

Wyznaczanie charakterystyki jednostkowego zużycia energii przez okrętowy układ napędowy ze śrubą o stałym skoku

Polanowski S., Pawletko R.

Logistyka

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2015

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nr 4

5349--5356, CD 2

PL

W referacie przedstawiono metodykę wyłaniania charakterystyk jednostkowego zużycia energii przez układ napędowy statku wypornościowego ze śrubą o stałym skoku. Wyłoniono dwa modele: model wielomianowy i potęgowy. Wykonano analizę modeli ze względu na minimum sumy kwadratów odchyleń oraz wartość odchyleni standardowego. Przeprowadzono analizę odchyleń w wyniku, której odrzucono ze zbioru danych wejściowych punkt pomiarowy piąty. Ostatecznie przyjęto model wielomianowy o potęgach całkowitych. Przeprowadzona analiza nie wyłoniła następnego członu aproksymującego. W szczególności model nie zawiera stałej. Zamieszczono wykres jednostkowego zużycia energii na milę morską (NM) dla przykładowego układu napędowego statku wypornościowego ze śrubą o stałym skoku, wykorzystując dane pomiarowe dla MS Garnuszewski.

EN

The paper presents a methodology for selecting the characteristics of the specific energy consumption by the of the ship propulsion system with a fixed pitch propeller. Emerged two models: the polynomial and power seriesmodel. Model analysis was performed because of the minimum sum of squared deviations, and standard deviation. An analysis of variations by which the discarded from the set of input data a fifth measuring point. Finally a model of the powers of the polynomial. The analysis did not identify the next member of approximating. In particular, the model does not include a constant. A chart of specific energy consumption per nautical mile (NM) for an example of the propulsion system fixed pitch propeller was shown, using the measurement data for the MS Garnuszewski.

4

Influence of the indicator diagrams smoothing on the indicated parameters of marine diesel engines

Pawletko R.

Journal of KONES

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2015

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Vol. 22, No. 2

169--176

EN

The topic of this article is to analyze the influence of indicator diagrams smoothing methods on diagnostic parameters determined on their basis such as the maximum combustion pressure, mean indication pressure and heat release characteristics. Indicator diagrams of marine engines are subject to serious distortions arising primarily from the measuring method for in-cylinder pressure. Measurements are performed on the indicator valve which connect with the combustion chamber through the indicator channel. Depending on the engine design the channel length can reach a considerable length and introduces significant distortion in both the phase and amplitude of the pressure signal. Further analysis of the indicator diagram eg. in order to determine the heat release characteristics requires the use of methods of smoothing and filtering of interference. The results confirm no effect of indicator diagram smoothing for the value of the mean indicated pressure, which is one for the most important indicated parameters. A significant influence of smoothing on the maximum value of the heat release rate was observed. The differences in this case exceed 50%. At the same time confirmed that the heat release rate curve determined on the basis of a diagram without smoothing, carry a high level of interference, which precludes their practical use. Smoothing allows getting heat release rate curves that carry vital information about the working process of the engine.

5

Ocena przydatności diagnostycznej wykresów indykatorowych w funkcji czasu bez znacznika położenia GMP

Pawletko R., Polanowski S.

Logistyka

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2014

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nr 6

1037--1042, CD 2

PL

W artykule przedstawiono wyniki badań do- świadczalnych, których celem była ocena przydatności diagnostycznej wykresów indykatorowych wykonanych w funkcji czasu, bez znacznika położenia GMP tłoka. Wykresy wykonywane w funkcji czasu są bardzo często wykorzystywane w praktyce okrętowej do diagnostycznej oceny okrętowych silników tłokowych. Wykresy tego typu uzyskuje się za pomocą tzw. Przenośnych indykatorów elektronicznych. Niewątpliwą zaletą tego typu urządzeń jest ich stosunkowo niska cena oraz łatwość pomiaru ciśnień w cylindrze, ponieważ nie jest konieczne instalowanie dodatkowych znaczników na wale silnika służących do określenia punktów charakterystycznych wału korbowego. W artykule przedstawiono wyniki badań uzyskanych przenośnym indykatorem elektronicznym Unitest 205. Pomiary wykonano na silniku laboratoryjnym Sulzer 3AL25/30 w zakresie obciążeń od 25 do 70 % obciążenia znamionowego. Uzyskane wykresy indykatorowe zostały porównane z wykresami otrzymanymi za pomocą indykatora stacjonarnego wyposażonego kątowy znacznik położenia wału korbowego. Indykator stacjonarny został wykorzystany jako poziom odniesienia dla wykresów z indykatora przenośnego.

EN

The article presents the results of experimental studies, which aim was to evaluate the diagnostic usefulenss of the indicator diagrams taken as a function of time, without the TDC location markres. Indicator diagrams made as a function of time are often used in practice for the diagnostic assessment of marine diesel engines. This type of diagrams are obtained by means of the so-called portable electronic indicators. An important advantage of such devices is their relatively low price and ease of measurement of the pressure in the cylinder, since it is not necessary to install additional markers on the crankshaft. The article presents the results of the survey for portable electronic indicator Unitest 205. Measurements were performed on a laboratory engine Sulzer 3AL25 / 30 load range from 25 to 70% of nominal load. Indicator diagrams obtained were compared with the diagrams obtained using the stationary indicator-equipped with angular crankshaft position marker. Stationary indicator was used as the reference level for diagrams with a portable indicator.

6

Analiza metod ograniczania emisji energetycznej przez statki

Polanowski S., Pawletko R.

Logistyka

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2014

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nr 6

8867--8874

PL

Siłownie okrętowe statków są bezpośrednio odpowiedzialne za emisję energetyczną, tzn. emisję GHG (GreenHouse Gas). W siłowniach jest wytwarzana energia niezbędna do napędu statku, zabezpieczenia jego funkcjonowania i warunków bytowych załogi oraz koniecznej dla przyjęcia, utrzymania w wymaganej kondycji i zdania przewożonego ładunku. Na wskaźniki poziomu emisji energetycznej ma wpływ sprawność siłowni oraz rodzaj stosowanych paliw. Określona ilość emisji CO2 i ciepła ma miejsce także podczas postoju statku nawet jeżeli konieczna do tego energia jest pobierana z zewnątrz. Kolejnym elementami odpowiedzialnym za poziom emisji energetycznej są pędniki i opory kadłuba. Każde polepszenie sprawności w tej dziedzinie w literaturze naukowo-technicznej jest łączone ze stopniem zmniejszenia emisji CO2. Zużycie paliw i poziom emisji energetycznej związane z wyprodukowaniem energii do napędu statku dla statku rośnie w przybliżeniu do trzeciej potęgi prędkości statku. Stąd powstaje kolejne zagadnienie takiego doboru prędkości statku żeby minimalizować emisję energetyczną oraz koszty transportu i maksymalizować zysk. Powyższe cele mogą być niekiedy sprzeczne. Ważnymi czynnikami wpływającymi na emisję przez statki lub zespół statków jest organizacja transportu oraz dobór tras z uwzględnieniem pogody.

EN

Engine rooms of the vessels are directly responsible for the energy emission, ie. emission of GHG (Green House Gas). The engine roomgenerates energy required for ship propulsion, securing its functioning and living conditions of personnel and necessary for the cargo operation. On indicators of energy emissions will affect the efficiency of the engine room and the type of fuel used. The specific CO2 and heat emissions also occurs during the ship is in harboureven if the energy is drawn from the outside. Another element responsible for energy emissions are propellers and hull resistance. Any improvement in efficiency in the field of literature, science and technology is combined with the degree of reduction in CO2 emissions. Fuel consumption and emissions energy production related energy for ship propulsion increases approximately to the third power of the speed of the ship. Hence arises another issue such a choice of ship speed to minimize the emission of energy and transportation costs and maximize profit. These objectives can sometimes be contradictory. Important factors influencing the emissions from vessels or vessels group is the organization of transport and the selection of routes, taking into account the actual weather.

7

The possibility of fuel injection pump diagnosis on the basis of indicator diagram

Pawletko R.

Journal of KONES

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2014

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Vol. 21, No. 1

215--221

EN

The paper presents the results research related to the possibility of fuel injection pump diagnosis on the basis of indicator diagram. The study was conducted on a laboratory four-stroke marine engine, type Sulzer 3Al 25/30, with nominal power Nen = 408 kW at nominal rotational speed n = 750 rpm. The study was carried out according to active experiment plan, during which the engine failure of the injection system was simulated. Simulation of fuel pump leakage was completed by the opening of the adjusting screw on the pump discharge. Measurements were made at a constant engine speed of 750 rev/min for five loads: 50, 100, 150, 200, 250 kW. Measurements of pressure of combustion were performed by means of tensometric sensors of Spice Company. Based on measured pressure curves heat release characteristics were determined. The algorithm allows the determination of net heat release rate q and the net generated heat Q characteristics. Based on the obtained results it can be concluded that significant improvement in the diagnostic use of indicator diagrams can be obtained by using heat release characteristics. These characteristics are correlated with the process of fuel injection and the injection pump operation. As demonstrated in the work of analyzing the heat release rate q, it is possible to infer diagnosis on the technical condition of the fuel injection system.

8

Increasing the accuracy of the mean indicated pressure determination by appointment of the TDC cylinder position

Pawletko R.

Journal of KONES

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2014

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Vol. 21, No. 2

251--258

EN

The paper describes the problems of mean indicated pressure determination and the piston TDC (Top Dead Centre) position impact on this parameter in marine diesel engines. Mean indicated pressure Pi is one of the most important diagnostic parameters of marine engines. On the basis of its parameter, the assessment of the technical condition of each cylinder as well as the regulation of injection equipment can be made. Most of the available electronic indicators enable automatic calculation of mean indicated pressure on the basis of progress indicator diagram. As the research shows the greatest impact on the accuracy of the designation mean indicated pressure has errors of piston TDC position. These errors can be significant and therefore this may lead to engine misdiagnosis. The actual piston TDC correction methods were discussed, and they justified the need of their use in marine engines, despite the wide use of methods of determining the angular position of the crankshaft. The original method of TDC correction based on the model of curve of the compression with the exponent of a polynomial was introduced. The proposed method of TDC correction has been verified for a different types of marine engines.

9

Increasing the accuracy of the mean indicated pressure determination by appointment of the TDC cylinder position

Pawletko R.

Journal of KONES

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2014

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Vol. 21, No. 4

397--404

EN

The paper describes the problems of mean indicated pressure determination and the piston TDC (Top Dead Centre) position impact on this parameter in marine diesel engines. Mean indicated pressure Pi is one of the most important diagnostic parameters of marine engines. On the basis of his parameter, the assessment of the technical condition of each cylinder as well as the regulation of injection equipment can be made. Most of the available electronic indicators enable automatic calculation of mean indicated pressure on the basis of progress indicator diagram. As the research shows the greatest impact on the accuracy of the designation mean indicated pressure has errors of piston TDC position. These errors can be significant and therefore this may lead to engine misdiagnosis. The actual TDC piston correction methods were discussed, and were justified the need of their use in marine engines, despite the wide use of methods of determining the angular position of the crankshaft. The original method of TDC correction based on the model of curve of the compression with the exponent of a polynomial was introduced. The proposed method of TDC correction has been verified for different types of marine engines.

10

Evaluation of current developments and trends in the diagnosis of marine diesel engines based on the indicator diagrams analysis

Pawletko R., Polanowski S.

Journal of KONES

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2014

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Vol. 21, No. 4

389--396

EN

The paper analyses the current offer of combustion pressure sensors for use on marine engines under operating conditions, methods of data acquisition, methods of determining TDC position and methods of obtaining diagnostic information from the indicator diagrams. Terms of continuous work on marine engines themselves only: new ABB cylinder pressure sensor, the piezoelectric sensors from KISTLER and AVL companies, but with limitations, the main ones being stability at high temperature. Another important issue for the accuracy of mean indicated pressure and heat released characteristics determination is referred to TDC position on the indicator diagrams. TDC is appropriate thermodynamic point, it is hardly determinable in the presence of interference and lack of sufficient information – but is used, for example in ABB solution. One of the sources of diagnostic information is to analyse trends in some parameters, which, unfortunately, is very difficult in environments with varying engine loads. Further progress in the diagnostic use of indicator diagrams should be associated with the use of the heat released characteristics and the net internal efficiency, which as shown by the results of preliminary tests can be used to assess the accuracy of the injection and combustion of fuel, including gas fuel. Supplementing these methods may be the use of vibration and noise to detect certain malfunctions.

11

Influence of clogged injector nozzles on the heat release characteristics

Pawletko R., Polanowski S.

Journal of KONES

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2013

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Vol. 20, No. 3

307--314

EN

The paper presents the results of research of the influence of clogged injector nozzles in fuel injection system on the shape of heat release characteristics. The study was conducted on a laboratory four-stroke marine engine, type Sulzer 3Al 25/30, with nominal power Ne = 408 kW at nominal rotational speed n = 750 rpm. The study was carried out according to active experiment plan, during which the engine failure of the injection system was simulated. Simulation of loss of patency of injector nozzles (clogged) was to completely clog two holes of nine injection injector nozzle holes with a diameter of 0,325 mm. Measurements were made at a constant engine speed of 750 rev/min for five loads: 50, 100, 150, 200, 250 kW. Measurements of pressure of combustion were performed by means of tensometric sensors of Spice Company. Based on measured pressure curves heat release characteristics were determined. The algorithm allows the determination of net heat release rate q and the net generated heat Q characteristics. Based on the obtained results it can be concluded that significant improvement in the diagnostic use of indicator diagrams can be obtained by using heat release characteristics. These characteristics are correlated with the process of fuel injection and the injection pump operation. As demonstrated in the work of analysing the heat release rate q, it is possible to infer diagnosis on the technical condition of the fuel injection system.

12

Assessment of the diagnostic suitability of net thermal efficiency of marine diesel engine

Pawletko R., Polanowski S., Witkowski A.

Journal of KONES

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2013

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Vol. 20, No. 4

327--332

EN

This article applies to searching for symptoms and diagnostic parameters pointing in a deterioration in the quality of the combustion process in marine diesel engines. It was assumed that diagnostic parameters should give clear information regardless of engine load or with respect to the mean indicated pressure. The proposed cycle and sectional net thermal (heat) efficiency characteristics and also dimensionless net heat release rate were analysed. In order to obtain the state of deterioration of the injection process simulation of discalibration (larger diameter) of injector holes was performed. The simulation was carried out by the enlarged of diameter of the injector holes form 0.375 mm to 0.385 mm. Deterioration of the formation and growth of fuel spray droplet diameter is result of such simulation. The study was conducted on a laboratory engine Sulzer Al25/30. The study was carried out according to active experiment plan, during which the selected engine failure of the injection system was simulated. Measurements of pressure of combustion were performed by means of tensometric sensors of Spice Company on the indicator valve. The analysis found that in the event of injector nozzle faults (discalibrated holes) significantly decreases the net thermal efficiency η c cycle, and there are significant oscillations of net

13

Influence of pressure sensor location on the quality of thermodynamic parameters calculated from the marine engine indicator diagram

Polanowski S., Pawletko R., Witkowski K

Combustion Engines

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2013

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R. 52, nr 3

319--323

EN

A major problem for the diagnostic use of the indicator diagram is the pressure sensor location. Indicator channel and valve may bring in significant distortions in the resulting pressure. The paper presents results of research conducted on the medium speed laboratory engine Al 25/30. Indication was made by the sensor placed directly in the cylinder (instead of starting air valve), before the indicator valve (with special Kistler adapter) and on the indicator valve. During the research the course of heat release rate q and the heat released Q were determined. Distortion of heat release characteristics for the sensor placed in the indicator valve is important, but it is estimated that diagnostic information is not lost. Influence of the pressure sensor location can be significantly reduced by proper adjustment of the TDC position.

PL

Jednym z głównych problemów diagnostycznego wykorzystania wykresów indykatorowych jest miejsce umieszczenia czujnika ciśnienia. Kanały oraz zawory indykatorowe są źródłem istotnych zakłóceń pomiarowych. W artykule przedstawiono wyniki badań dotyczących miejsca zamocowania czujnika ciśnienia spalania na silniku laboratoryjnym Sulzer Al25/30. Czujniki ciśnienia zostały umieszczony bezpośrednio w cylindrze (w miejsce zaworu startowego), przed zaworem indykatorowym oraz na zaworze indykatorowym. Oprócz podstawowych parametrów indykowanych na podstawie wykresów indykatorowych wyznaczono przebieg charakterystyk prędkości wydzielania ciepła oraz ciepła wydzielonego. Na podstawie uzyskanych wyników badań stwierdzono, że kanały gazowe silników średnioobrotowych wnoszą znaczące opóźnienia sygnałów ciśnienia i deformacje wykresów indykatorowych, jednak możliwe jest w dalszym ciągu ich diagnostyczne wykorzystanie. Wpływ lokalizacji czujnika ciśnienia może być istotnie zmniejszony poprzez prawidłową korektę położenia GMP.

14

Influence of fuel injection system faults of marine diesel engine on the heat release characteristics

Pawletko R., Polanowski S.

Combustion Engines

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2013

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R. 52, nr 3

314--318

EN

The paper presents the results of research of the influence of chosen marine diesel engine fuel injection system faults on the shape of heat release characteristics. The study was conducted on a laboratory engine Sulzer Al25/30. The study was carried out according to active experiment plan, during which the selected engine failure of the injection system were simulated. Measurements of pressure of combustion were performed by means of tensometric sensors of Spice Company. Based on measured pressure curves heat release characteristics were determined. The algorithm allows the determination of heat release rate q and the generated heat Q characteristics. Based on the obtained results it can be concluded that significant improvement in the diagnostic use of indicator diagrams can be obtained by using heat release characteristics. These characteristics are correlated with the process of fuel injection and the injection pump operation. As demonstrated in the work of analyzing the heat release rate q, it is possible to infer diagnosis on the technical condition of the fuel injection system.

PL

W artykule przedstawiono wyniki badań wpływu wybranych uszkodzeń układu wtryskowego silnika okrętowego na przebieg charakterystyk wydzielania ciepła. Badania przeprowadzono na laboratoryjnym silniku Sulzer typu Al25/30. Doświadczenie zrealizowano zgodnie z planem eksperymentu czynnego, podczas którego symulowano wybrane uszkodzenia układu wtryskowego. Indykowanie silnika wykonano za pomocą tensometrycznych czujników spalania firmy Spice. Wykorzystując uzyskane wykresy indykatorowe wyznaczono charakterystyki wydzielania ciepła. Zastosowania algorytmy umożliwia obliczenia szybkości wydzielania ciepła q oraz ciepła wydzielonego Q. W oparciu o uzyskane wyniki badań można stwierdzić, zastosowanie charakterystyk wydzielania ciepła, może w sposób istotny wpłynąć na podatność diagnostyczną wykresów indykatorowych. Potwierdzono istotną korelację pomiędzy działaniem układu wtryskowego a przebiegiem tych charakterystyk. W oparciu o uzyskane przebiegi szybkości wydzielania ciepła, możliwe diagnozowania badanych uszkodzeń układu wtryskowego.

15

The use of expert system for marine diesel engine diagnosis

Charchalis A., Pawletko R.

Zeszyty Naukowe Akademii Marynarki Wojennej

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2012

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R. 53 nr 1 (188)

49-56

EN

The paper presents a diagnostic system for marine diesel engine based on an expert system model. The research relevant to knowledge acquisition for this system was done, knowledge data set was built and general structures of the expert system was proposed. Basic sources of knowledge which can be used for construction of knowledge data set are also identified. The basic knowledge related to the diesel diagnostic was undertaken from experts and diagnostic data base. The paper questionnaire was used to the knowledge acquisition from experts. The basic knowledge related to the marine diesel exploitation was undertaken. The rule induction algorithms was used to knowledge acquisition from data base. During the experiment efficiency of LEM induction algorithms was compared to new MODLEM and EXPLORE algorithms. Training and test data were acquired from experiment on marine engine Sulzer 3AL 25/30.

PL

Artykuł przedstawia system diagnostyczny okrętowego silnika wysokoprężnego oparty na modelu systemu eksperckiego. Przeprowadzono badania odpowiednia dla pozyskania informacji o tym systemie, stworzono zestaw danych oraz zaproponowano struktury ogólne systemu eksperckiego. Zidentyfikowano również podstawowe źródła informacji, które mogą być wykorzystane do budowy zestawu danych wiedzy. Podstawowa wiedza odnosząca się do diagnostyki silników wysokoprężnych została wzięta z eksperckich i diagnostycznych baz danych. Wykorzystano kwestionariusz papierowy w celu uzyskania wiedzy od ekspertów. Uzyskano podstawowe informacje odnoszącą się do eksploatacji silników okrętowych. Zastosowano algorytmy rule induction do uzyskania informacji z bazy danych. Podczas eksperymentu sprawność algorytmów induction LEM została porównana z nowymi algorytmami MODLEM i EXPLORE. Dane szkoleniowe i testowe zostały uzyskane z eksperymentu na silniku okrętowym Sulzer 3AL 25/30.

16

Low speed marine diesel engine diagnosis based on passive experiment

Polanowski S., Pawletko R.

Journal of Polish CIMAC

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2012

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Vol. 7, no 2

161-166

EN

Analysis of the indicator diagram is the basis of technical state evaluation of marine diesel engines. The indicator diagram contains a large amount of diagnostic information. In most cases, analysis of the graph is reduced to determination only the maximum pressure or mean indicated pressure. It seems appropriate to determine the possibility of use heat release characteristics for the diagnostic purpose. The paper presents results of studies related to the use of indicator diagrams for the diagnosis of high power marine diesel engine. The results include a comprehensive approach to problems of use of the cylinder pressure curves for the evaluation of the technical condition of the engine. The problem of dynamic adjustment of the GMP position, smoothing distortions due to the impact of the channel and indicator valve were considered. Diagnostic analysis includes also the designation of the heat release characteristics on the basis of the curves pressure in the engine cylinder. The algorithms allow to determine both the curves of heat release rate q and the heat released Q. The curve of heat release rate q is a full equivalent to fuel injection pressure curve in the fuel pipes. It allows identification of the failure of the injection system. The curve of Q allows such determination and additional assessment of internal efficiency of the cylinder. The analyzed indicator diagrams were obtained during the sea voyage with the use of the stationary electronic indicator PREMET. The pressure sensor were placed on the indicator valves.

17

Influence of gas channels of medium speed marine engines on the accuracy of determination of diagnostic parameters based on the indicator diagrams

Pawletko R., Polanowski S.

Journal of Polish CIMAC

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2012

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Vol. 7, no 2

139-146

EN

Analysis of the indicator diagram is the basis of technical state evaluation of marine diesel engines. The indicator diagram contains a large amount of diagnostic information. A major problem for the diagnostic use of the indicator diagrams in case of medium speed engines are distortion caused by the gas channels between the cylinder and the pressure sensor. Indicator channel and valve may introduce significant distortions which increases with increasing engine speed. The paper presents results of results of the analysis of the indicator diagram of engines in onboard service, and research conducted on the medium speed laboratory engine Al 25/30. These engines are characterized by gas channels of high complexity. During laboratory research pressure measurement (indication) was made by the sensor placed directly in the cylinder (instead of starting air valve), before the indicator valve (with special Kistler adapter) and on the indicator valve. Distortion of heat release characteristics for the sensor placed on the indicator valve is important, but it is estimated that diagnostic information is not erased. For medium speed engines is to be expected the use of a portable pressure sensors placed on the indicator valve. For this reason, further research is needed to assess the impact of channels and valves on different cylinders. During the research the course of heat release rate q and the heat released Q were determined. The curve of heat release rate q is a full equivalent to fuel injection pressure curve in the fuel pipes. It allows identification of the failure of the injection system. The curve of Q allows such determination and assessment of internal efficiency of the cylinder.

18

Wyznaczanie GMP silników okrętowych z zastosowaniem wielomianowego modelu wykładnika krzywej sprężania

Polanowski S., Pawletko R.

Silniki Spalinowe

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2011

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R. 50, nr 3

PL

W artykule przedstawiono model procesu sprężania bazujący na wykładniku wielomianowym. Przebieg sprężania przybliżono modelem, w którym wykładnik politropy zastąpiono wielomianem potęgowym trzeciego stopnia w funkcji drogi tłoka. Oprócz pięciu parametrów pomocniczych, głównymi parametrami modelu są: położenie GMP tłoka, całkowity stopień sprężania, offset wykresu indylatorowego i parametr układu korbowego λ, którego wartość jest na ogół znana. Do modelu wprowadzono także funkcję przedmuchów gazu, której postać jest obecnie zakładana. Wartości parametrów wyznaczane są metodą najmniejszych kwadratów oraz metodami teorii eksperymentu. Metodę sprawdzono na silnikach okrętowych różnych typów, dla pomiarów wykonywanych na zaworach indykatorowych czujnikami różnych typów oraz dla różnych metod generowania osi kątowej, które to czynniki nie są brane pod uwagę w przypadku metod prezentowanych w dostępnej literaturze. Opracowany model umożliwia pewne oraz powtarzalne wyznaczanie położenia GMP tłoków silników okrętowych z dokładnością wystarczającą dla celów diagnostycznych i sięgającą ± 0,05 ° OWK.

EN

The paper presents a model of the compression process based on the polynomial exponent. The courve of compression was approximated with model in which the polytropic exponent was replaced by a polynomial of third degree as a function of the piston way. In addition to the five auxiliary parameters, the main parameters of the model are: piston TDC position, the total compression ratio, indication graph offset and crank system parameter λ, which value is generally known. The function of gas blowing was also introduced to model, which shape is pressently assumed. Parameters values were determined by the least squares methods and the theory of experiment. The method was tested on various types of ship engines, for measurements performed on the indicator valves of the different sensors and for different methods of generating the angular axis, which factors are not taken into account for the methods presented in the literature. The proposed model allows a reliable determination of the piston TDC position with an accuracy sufficient for diagnostic purposes and reaching ± 0,05 ° CA.

19

Wpływ błędu położenia GMP oraz offsetu ciśnienia na wartość całkowitego stopnia sprężania wyznaczanego na podstawie wykresu indykatorowego silnika okrętowego

Pawletko R., Polanowski S.

Silniki Spalinowe

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2011

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R. 50, nr 3

PL

W artykule przedstawiono wyniki badań wpływu błędu określania górnego martwego położenia tłoka (GMP) oraz błędu ciśnienia początkowego (offset) na wartość całkowitego stopnia sprężania wyznaczonego na podstawie przebiegu wykresu indykatorowego. Do wyznaczania wartości całkowitego stopnia sprężania zastosowano metodę aproksymacji najmniejszych kwadratów na odcinku przedziału sprężania modelem bazującym na wykładniku wielomianowym. Badania przeprowadzono na silniku laboratoryjnym Sulzer 3AL25/30 w zakresie obciążeń 100-300 kW i prędkości obrotowej 750 obr/min, co odpowiada zakresowi 25-75 % obciążenia znamionowego. Do analizy wykresów indykatorowych wykorzystano własny, specjalnie opracowany algorytm i program automatycznego wyznaczania GMP. Wyznaczano jednocześnie trzy parametry: położenie GMP, całkowity stopień sprężania i offset ciśnienia. Badania wykazały istotność wpływu badanych parametrów na wartość całkowitego stopnia sprężania.

EN

The article presents the research results of TDC position error and offset pressure influence on the value of the total compression ratio determined with the base of marine engine indicator graph. For TDC determination the method based on least-squares approximation with model of thermodynamic compression using a polynomial exponent was applied. Research were done on the laboratory engine Sulzer 3AL25/30 for load range of 100-300 kW and rotational speed 750 rpm, which corresponds to 25-75% nominal load. Specially developed algorithm and program for the automatic determination of TDC was used for the analysis of indicator diagrams. During the calculation three parameters was determined simultaneously: the position of TDC, the total compression ratio and offset pressure. The results of research have shown the essential influence of the tested parameters on total compression ratio.

20

Knowledge management system for marine diesel engine diagnosis

Charchalis A., Pawletko R.

Journal of KONES

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2011

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Vol. 18, No. 2

77-83

EN

The paper presents the conception of knowledge management system for a diagnostic expert system. Development of knowledge management system is necessary during the construction of the expert system. The most important reason is that knowledge in this system is not a static whole, but is subject to dynamic growth, is modified and updated. Advantages afforded by the creation of diagnostic systems based on knowledge, such as expert systems, compared to traditional diagnostic systems based on closed algorithms were characterized. The conception of knowledge management system established in the diagnostic work associated with the development of expert system for marine diesel engine diagnosis. The main elements of the developed management system are: dictionary editor, rule editor, knowledge assessment module and import and export module. Knowledge management system is also equipped with an electronic form that is used to obtain knowledge from experts, specialists in diesel engines operation. The article presents the tasks and the performance of individual components of the system. The knowledge management system enables integration within a single frame of both information collected from experts and automatically collected one. A doubtless advantage of expert system is the opportunity of updating and developing the content recorded in the database. Due to this feature, the effectiveness of the system may grow during engine operation and facilitate gaining new experience.