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Attempt of injectors failure detection based on measurement of the angular speed discrete value

Dereszewski M., Charchalis A.

Journal of KONES

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2013

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Vol. 20, No. 3

131--137

EN

The paper presents results of the experiment focused on detection of faulty injector of medium speed diesel engine, in way of analysis of IAS (Instantaneous Angular Speed) of the crankshaft. The experiment was carried out at laboratory stand in Gdynia Maritime University, equipped with diesel engine Sulzer 3AL 25/30 driving electrogenerator. Sulzer 3AL 25/30 is three cylinder, medium speed, four stroke marine diesel engine, with maximum output 400 kW at 750 rpm. In order to evaluate of IAS utility for diagnosis of the engine, two kinds of wrong adjustment of fuel injection valve’s spring were simulated. First malfunction was too weak spring (initial tension of 15.0 MPa against 25.0 MPa in normal condition), the second was too strong tension of the spring (35.0 MPa). The base of experiment was to angular speed recording, in three different conditions of the engine: healthy one and with two simulated malfunctions. Measurements were carried out at two different loads, respectively 150 kW and 250 kW. The IAS was measured and recorded by the measurement system ETNP-10, which mode of operation was based on perforated disc mounted at the shaft and photo-optic sensor counting laser impulses. Noise decomposition of measurement results was based on triple smoothing using Savitzky-Golay filter. IAS runs of faulty engine were compared with healthy engine measurement, in order to detect all deviation from normal condition.

2

Evaluation of diagnostic information about marine engine work based on mesurement of the angular speed discrete value

Dereszewski M., Charchalis A., Polanowski S.

Journal of KONES

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2012

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Vol. 19, No. 2

121-128

EN

The paper presents results of the experiment, aimed on finding the answer whether IAS (Instantaneous Angular Speed) and angular acceleration of the crankshaft is carrying information about quality of combustion in cylinder of the diesel engine. The experiment was carried out at laboratory stand in Gdynia Maritime University, equipped with diesel engine Sulzer 3AL 25/30 driving electro-generator. Sulzer 3AL 25/30 is three cylinder, medium speed, four stroke marine diesel engine, with maximum output 408 kW at 750 rpm. In order to evaluate of IAS utility for diagnosis of the engine, two kinds of malfunctions of engine's fuel system were simulated. First malfunction was fuel leakage from high-pressure line; the second was partly plugged injector's nozzle. Construction of high-pressure fuel pump enables to simulate fuel leakage. The level of leakage was controlled by simultaneous measurement of pressure in the high-pressure tube. For simulation of injector malfunction, the chocked one was installed in second cylinder. The engine was running at different loads, starting from around 25% up to 70% of nominal. The IAS was measured and recorded by the measurement system ETNP-10, which mode of operation was based on perforated disc mounted at the shaft and photo-optic sensor counting laser impulses. Results of all measurement were smoothed in order to eliminate a noise. Measurement results of fault condition were compared with healthy engine measurements and with results of in-cylinder pressure diagrams, in order to detect all deviation from normal condition.

3

Analysis of crankshaft’s angular velocity waveforms as a method of long term monitoring of engine performance quality

Dereszewski M.

Zeszyty Naukowe / Akademia Morska w Szczecinie

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2011

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nr 28 (100) z. 1

14-18

EN

The paper presents an idea to utilize crankshaft’s angular speed variation and its derivative for monitoring of trouble of Diesel engine combustion quality. Measurement of instantaneous angular speed, recording and archive of values is easy to obtain using optical indicator and programmable logic controller. Advantage of this method is simple installation and constant signal. Collected data can be processed on board, basing on MS Excel formulas. Observation of changes of instantaneous speed and acceleration can not replace more accurate monitoring systems like Main Effective Pressure measurement or vibration monitoring, but is an excellent tool for early warning. When a signal about deteriorating of engine performance is obtain, more accurate diagnostic can be implemented. Expected final result will be elimination of engine’s cycle’s irregularity. Proposed method is at early stage of investigation and further steps to prove its utility and to develop concluding rules are to be conducted. In the paper are presented preliminary analysis of some bunches of data collected from two bulk carriers, operating in similar condition.

PL

W artykule przedstawiono ideę wykorzystania funkcji zmian prędkości kątowej wału korbowego oraz jej pochodnej do monitorowania zakłóceń równomierności pracy cylindrów. Pomiar prędkości chwilowej, zapis i archiwizacja wartości jest łatwe do uzyskania przy zastosowaniu głowicy fotooptycznej sprzężonej ze sterownikiem programowalnym. Zalety powyższej metody to łatwość instalacji systemu oraz uzyskiwanie bieżącego sygnału. Zebrane dane mogą być obrabiane na statku w oparciu o formuły zapisane w programie MS Excel. Obserwacja zmian chwilowej prędkości i przyspieszenia kątowego nie zastąpi typowych pomiarów, takich jak pomiar ciśnienia indykowanego lub monitoring drgań, jest jednak doskonałym narzędziem do wczesnego informowania i ostrzegania. W przypadku otrzymania sygnału o pogarszającym się stanie jakości pracy silnika można przystąpić do dokładnego ustalenia przyczyn przy pomocy dokładnych metod pomiarowych. Oczekiwanym efektem finalnym tych działań powinno być usunięcie przyczyn nieregularnej pracy silnika. Przedstawiona metoda jest na wczesnym etapie badań i wymaga dalszych analiz w celu wykazania jej użyteczności diagnostycznej. W artykule przedstawiono wstępne analizy pakietów danych pochodzących z dwóch masowców operujących w podobnych warunkach.