Wyniki wyszukiwania - BazTech

1

Wpływ wzrostu dawki paliwa na zmiany amplitud składowych harmonicznych drgań skrętnych wału zespołu spalinowo-elektrycznego

Drewing S., Dereszewski M.

Zeszyty Naukowe Akademii Morskiej w Gdyni

|

2018

|

nr 108

34--42

PL

Artykuł przedstawia wyniki badań wpływu zmian dawki paliwa na składowe harmoniczne drgań skrętnych wału zespołu spalinowo-elektrycznego, ze szczególnym uwzględnieniem składowej harmonicznej odzwierciedlającej wtrysk paliwa. W badaniach wykorzystano metodę pomiaru drgań skrętnych wału za pomocą zmian chwilowych prędkości kątowych.

EN

The article presents the results of research on the impact of changes in the fuel dose on the harmonic components of torsional vibrations of the shaft of the combustion-electric unit, with particular emphasis on the harmonic component responsible for fuel injection. In the tests, the method of measuring torsional vibrations of the shaft was used by means of changes of instantaneous angular velocities.

2

Processing of long lasting signals of torsional vibrations measured using incremental encoders

Dereszewski M., Sikora G.

Journal of KONES

|

2018

|

Vol. 25, No. 4

59--65

EN

The article describes processing method of a signal, coming from torsional deflections of an internal combustion piston engine’s crankshaft, registered using two optical encoders ETNP-10. Standard measurement and recording set ETNP-10 enables recording of Instantaneous Angular Speed values encompassing 10 revolutions of the crankshaft, what is equal to 5 cycles of four-stroke engine. That time duration is sufficient for analysis of changes of angular speed caused by, for example, malfunction of fuel injection valve, but is insufficient in case of observation characterized by low frequency changes with period of fluctuations, lower than 0.8 sec. Short time for recording makes impossible following of instantaneous angular speed deviations caused by magnitude modulation of engine’s load value. In the article is presented an algorithm written in MATLAB environment, which allows processing of the data recorded using the recorder DAS 1600 Sefram. The recorded this way signals have around 26 seconds' duration of engine work. Data acquired from two encoders mounted at opposite sides of the shaft, in form of square magnitude signals are transformed into instantaneous speed and subsequently to instantaneous angular shift, what is basis for torsions calculation. In the article is also presented method of elimination of systematic error due to assumed method of averaging. Finally, some examples of results of torsional deflection measurement and analysis are presented.

3

Diagnostic of malfunction of four stroke marine engine using harmonic components of combustion pressure waveforms

Drewing S., Dereszewski M.

Journal of KONES

|

2018

|

Vol. 25, No. 2

97--103

EN

The paper presents results of experimental measurements and analysis of combustion pressure and fuel pressure in high-pressure line before fuel valve. The aim of conducted experiments was detection of failures of high-pressure fuel system. Both pressure signals were recorded simultaneously and subsequently processed using FFT decomposition of obtained wavelets. The idea of comparison of both fuel and gas pressures came after observations of occurrence changes of wavelets form of fuel high pressure, probably caused by malfunction of injector's sprayer. The engine from test bed is very well armoured with sensors, what enable observations of fuel and combustion pressure in real time. Unfortunately, such equipment is very unlike in real objects, what created un idea to find out whether run of combustion pressure wavelet reflects fuel pressure deviations and whether is possible to detect such kind of deviations in way of decomposition of indicated pressure wavelet. Experiment was carried out in laboratory of Gdynia Maritime University, using medium speed diesel engine. Simulation of malfunctions of fuel valve was obtained by installation of specially prepared spraying nozzles. All measurements were carried out at reference load of 75% of MCR (Maximum Continuous Rating). In order to get reliable results and avoid errors due to omitting outer atmospheric conditions, registrations were repeated several times, in days characterized by different temperature and atmospheric pressure.

4

Diagnostic aspects of a crankshaft torsional oscillations monitoring by IAS measurement

Dereszewski M.

Journal of KONES

|

2018

|

Vol. 25, No. 1

67--74

EN

Continuous monitoring of diesel engine performance under its operating is critical for prediction of malfunction development and subsequently functional failure detection. Analysis of Instantaneous Angular Speed (IAS) of the crankshaft is considered as one of non-intrusive and effective method of detection of combustion quality deterioration. The article contains presentation of attempt of monitoring of piston engine’s crankshaft torsional vibrations by measurement of Instantaneous Angular Speed at free, and power output ends of the engine’s crankshaft. The angular speed measurements was done using two optical sensors for reading the IAS, mounted at shaft line’s opposite ends, one at free end of the crankshaft and second at end of generator’s shaft. In the article is presented description of the measurement system and explanation of its mode of work. Experiments were based at two kinds of malfunction possible to be simulated at test bed. First one was simulation of a leak of fuel injection pump, the second one relayed on mounting of sets of injection valves with different nozzles characteristics (spraying nozzle angle), giving different parameters of fuel injection. Presented results of experiment derives from test cycle carried out using laboratory stand of Gdynia Maritime University equipped with 3- cylinder self − ignition engine, powering electric generator.

5

Decomposition of harmonic wavelets of torsional vibrations as basis for evaluation of combustion in compression-ignition engines

Dereszewski M., Drewing S.

Journal of KONES

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2018

|

Vol. 25, No. 3

129--135

EN

The aim of analysis presented in the article is results of measurements of torsional deflections of a crankshaft of three-cylinder internal combustion diesel engine. The wavelets of the run of torsional twists were processed by decomposition to harmonics using FFT. In order to exactly recognize all dynamic aspects of gas forces acting during working stroke, decomposition was done in two ways: first one relaying on records encompassing one working cycle (two revolutions), the second one based at separated periods encompassing angular an interval from TDC (Top Dead Centre) of one cylinder to TDC of subsequent in firing order. For three-cylinder engine, width of the interval is 240 degrees of crank angle. In order to obtain reliable results, torsional deflection signals acquisitions were recorded numerous times including changes of outer conditions (temperature, atmospheric pressure) and different values of the engine loads. The main goal of conducted experiments was looking for an answer of a question if exist any differences between frequency spectrums of harmonics of run of full cycle ( two revolutions) and the same cycle divided by three separate intervals. Analysis was conducted in order to state any possibility of diagnostic signals acquisition caused by abnormalities of combustion process. Results were presented in form of comparison of frequency spectra taken from full cycle and divided intervals.

6

Test stand for monitoring of torsional vibration of engine’s crankshaft by instantaneous angular speed measurement

Dereszewski M.

Zeszyty Naukowe Akademii Morskiej w Gdyni

|

2016

|

nr 96

15--23

EN

Continuous monitoring of diesel engine performance under its operating is critical for prediction of malfunction development and subsequently functional failure detection. Analysis of Instantaneous angular Speed (IAS) of the crankshaft is considered as one of non intrusive, and effective method of detection of combustion quality deterioration.The paper contains presentation of attempt of monitoring of piston engine’s crankshaft torsional vibrations by measurement of Instantaneous Angular Speed at free and power output ends of the engine’s crankshaft. It is assumed that calculation of differentia value between both ends shall give the picture of torsion angle magnitudes and phases of the peak values. The angular speed measurements is to be done utilising two optical sensors for reading and two perforated discs mounted at shaft’s ends playing the role of speed signal emitters. In the paper is presented description of the measurement system and explanation of its mode of work. It is also shown analysis of measurement accuracy, way errors elimination and method of signals runs filtration. Presented results of experiment derives from test cycle carried out using laboratory stand of Gdynia Maritime University equipped with 3-cylinder self – ignition engine, powering electric generator.

7

Monitoring of torsional vibration of a crankshaft by instantaneous angular speed observations

Dereszewski M.

Journal of KONES

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2016

|

Vol. 23, No. 1

99--106

EN

Continuous monitoring of diesel engine performance under its operating is critical for prediction of malfunction development and subsequently functional failure detection. Analysis of Instantaneous angular Speed (IAS) of the crankshaft is considered as one of non-intrusive and effective method of detection of combustion quality deterioration. The paper contains presentation of attempt of monitoring of piston engine’s crankshaft torsional vibrations by measurement of Instantaneous Angular Speed at free and power output ends of the engine. It is assumed that calculation of differential value of angular distance run between both ends in the same time shall give the picture of torsion angle magnitudes and phases of the peak values. Fir carrying out such measurements, high frequency of sampling was required. The angular speed measurements is to be done utilising two optical sensors for reading and two perforated discs mounted at shaft’s ends playing the role of speed signal emitters. In the paper is presented description of the measurement system and explanation of its mode of work. It is also shown analysis of measurement accuracy, way errors elimination and method of signals runs filtration. Presented results of experiment derives from test cycle carried out using laboratory stand of Gdynia Maritime University equipped with 3- cylinder self - ignition engine, powering electric generator.

8

Impact of rise of exhaust resistance at torque and angular speed of two-stroke engine

Dereszewski M., Charchalis A.

Journal of KONES

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2015

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Vol. 22, No. 4

87--93

EN

It is assumed that elements of Exhaust Gases Cleaning Systems creates additional resistance along fumes duct and can affect energetic process of combustion. In the paper are presented results of researches aimed on detection and recognition of dumping effect in the exhaust pipeline using devices dedicated for engine’s torque and angular speed measurement. The experiment was carried out in test stand of Gdynia Maritime University; equipped with one-cylinder, low speed engine working in two-stroke mode. Effect of increasing of gas flow resistance was achieved by installation of shutters in cross-section of exhaust pipe. The shutters diminished active flow „window“ for 50% of normal crossection area of the exhaust pipe The plan of measurements encompasses registration of Instantaneous Angular Speed of the engine’s shaft and parallel registration of Instantaneous Value of Shaft Torsion, what reflect fluctuation of torque. Value of angular speed and toque enables exact calculation of power produced by the engine. Experiment included measurements at different levels of engine’s load and with changes of mean rotational speed. Angular speed and shaft’s torsion were measured and recorded using system ETNP-10 which is based on optical sensor and set of toothed discs. That method gives high accuracy of angular speed and torsion measurement. Results of experiment are presented as difference of related curves of values’ variations of angular speed and torsion occurring at the propulsion shaft connecting the engine and the water brake.

9

Zastosowanie momentomierza optycznego do monitorowania zmian wielkości siły gazowej w cylindrze silnika wysokoprężnego na podstawie obserwacji fluktuacji momentu i chwilowej prędkości kątowej wału korbowego

Dereszewski M., Charchalis A.

Logistyka

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2014

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nr 6

3071--3078

PL

W artykule przedstawiono propozycję pośredniego monitorowania wpływu instalacji oczyszczania spalin na parametry wyjściowe silnika wysokoprężnego w postaci momentu obrotowego oraz mocy, za pomocą czujnik opartego na zasadzie optycznej. Zastosowany układ pomiarowy pozwala na precyzyjny pomiar oraz rejestrację chwilowych wartości kąta skręcenia wału napędowego oraz jego prędkości kątowej. Metoda określania skręcenia wału za pomocą pomiaru przesunięcia dwóch tarcz referencyjnych zamontowanych w pewnym odstępie na wale jest stosowana w okrętownictwie od wielu lat, jednakże postęp jaki nastąpił w dziedzinie elektroniki oraz technice komputerowej pozwolił na osiągnięcie wymaganej dokładności pomiarów. Skuteczność metody potwierdziły badania wstępne przeprowadzone na silniku laboratoryjnym L 22, z wykorzystaniem urządzenia pomiarowego ENAMOR ETNP-10 oraz układu przesłon pozwalających na kontrolowane zmiany przeciwciśnienia w kanale wydechowym silnika.

EN

The paper presents a proposal of indirect monitoring of impact of exhaust gases purifying installation at outcoming parameters diesel engine as torque and revolutionary speed, using optical measurement system. Implemented system enables pretty accurate measurement and registration of instantaneous values of torque deriving torsions of the shaft and angular speed. The method of shaft torsion determination based on two reference discs mounted at a shaft is well known in marine industry, nevertheless technological progress done last years made that method much more accurate and reliable. Effectiveness of implemented system ETNP-10 was proved during experiment carried out at laboratory stand equipped with one-cylinder diesel engine and exhaust duct with adjustable slopes enabling controlled changes of gas counter pressure.

10

Validation of reference sampling for failure detection by crankshaft angular speed analysis

Dereszewski M., Charchalis A.

Journal of KONES

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2014

|

Vol. 21, No. 3

67--74

EN

The paper presents results of the experiment focused on evaluation of records of runs of the engine in good condition as a reference for subsequent detection of faults of fuel system of medium speed diesel engine. The aim of research was determination of limits of instantaneous angular speed's spread spotted between random starts of the engine, without any fault condition simulation. Due to fine variation of the load setup and different ambient condition, every record of angular speed of independent starting, despite of attempts to sustain the same load and rotational speed value, presents some deviations between runs. Having on mind utilization of such measurement as a template for further comparison, is crucial to find out how random changes of ambient conditions and accuracy of revolutionary speed setup affect the IAS magnitude course. The answer was got in way of registration of numerous runs of the test engine after independent starts and hand adjustment of required RPM’s. 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. Independent records were treated as random variable and were compared each other. Obtained results were compared with differences between healthy engine and with simulated malfunctions of fuel injection.

11

Validation of reference sampling for failure detection by crankshaft angular speed analysis

Dereszewski M., Charchalis A.

Journal of KONES

|

2014

|

Vol. 21, No. 4

63--70

EN

The paper presents results of the experiment focused on evaluation of records of runs of the engine in good condition as a reference for subsequent detection of faults of fuel system of medium speed diesel engine. The aim of research was determination of limits of instantaneous angular speed's spread spotted between random starts of the engine, without any fault condition simulation. Due to fine variation of the load setup and different ambient condition, every record of angular speed of independent starting, despite of attempts to sustain the same load and rotational speed value, presents some deviations between runs. Having on mind utilization of such measurement as a template for further comparison, is crucial to find out how random changes of ambient conditions and accuracy of revolutionary speed setup affect the IAS magnitude course. The answer was got in way of registration of numerous runs of the test engine after independent starts and hand adjustment of required RPM’s. The experiment was carried out at laboratory stand in GdyniaMaritimeUniversity, 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. Independent records were treated as random variable and were compared each other. Obtained results were compared with differences between healthy engine and with simulated malfunctions of fuel injection.

12

Impact of sea waving at fluctuation of instantaneous angular speed of ship’s propulsion shaft

Dereszewski M.

Journal of KONES

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2014

|

Vol. 21, No. 1

59--65

EN

The paper presents results of analysis how sea waves affect variation of angular speed of a propulsion shaft of the ship during sea passage. That information is necessary to evaluate the level of credibility of measurements taken as reference value for detection of main engine combustion failures and evaluation of cylinders’ contribution to total power based on shaft’s angular speed irregularity observations. Utilization of IAS (Instantaneous Angular Speed) for diagnostic purposes is mostly based on comparison of actual state measurement with characteristics taken during healthy engine run in certain outer conditions. All variations of atmospheric pressure and air temperature have noticeable impact at instantaneous value of angular speed, they and must be considered during comparison procedure. For marine propulsion set, two weather deriving factors, having impact at angular speed of the shaft, can occur. First one is mentioned above values of air temperature and air pressure, the second one is torque variations caused by changes of propeller’s draught due to pitch of the hull. Any deviations from sampling course of angular speed are treated as malfunction symptoms. The aim of analysis was to evaluate how pitching frequency affect run of IAS and how whether omitting of that impact can lead to wrong conclusions.

13

Validation of failure detection by crankshaft angular speed analysis under sea waving conditions

Dereszewski M.

Diagnostyka

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2014

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Vol. 15, No. 3

59--63

EN

The paper presents results of analysis how sea waves affect variation of angular speed of a propulsion shaft of the ship during sea passage. That information is necessary to evaluate the level of credibility of measurements taken as reference value for detection of main engine combustion failures and evaluation of cylinders’ contribution to total power based on shaft’s angular speed irregularity observations. Utilization of IAS (Instantaneous Angular Speed) for diagnostic purposes is mostly based on comparison of actual state measurement with characteristics taken during healthy engine run in certain outer conditions. For marine propulsion set, the weather deriving factor, having impact at angular speed of the shaft, is torque variation caused by changes of propeller’s draught due to pitch of the hull. The aim of analysis was to evaluate how pitching frequency affect run of IAS and how to process obtained data to eliminate harmonics deriving from sea waving.

PL

W artykule zaprezentowano rezultaty analizy wpływu falowania morza na zmiany chwilowej prędkości kątowej wału napędowego statku podczas rejsu morskiego. Wnioski z powyższej analizy są niezbędne do oszacowania poziomu wiarygodności rezultatów pomiarowych przyjętych jako wartości porównawcze służące do wykrywania nieprawidłowości procesu spalania w poszczególnych cylindrach silnika o zapłonie samoczynnym. Metoda diagnostyczna oparta na ocenie zmian chwilowej prędkości kątowej wału wymaga porównania wartości uzyskanych w chwili dokonywania oceny stanu technicznego z wartościami wzorcowymi uzyskanymi z badania silnika będącego w doskonałym stanie technicznym. Na pracę układu napędowego statku mają wpływ czynniki atmosferyczne a jednym z nich jest falowanie morza, powodując zakłócenia regularności prędkości obrotowej wału wskutek zmiennego zanurzenia śruby napędowej. Celem analizy było sprawdzenie czy matematyczna obróbka danych może wyeliminować składowe od falowania morza.

14

Wykorzystanie modelu dynamicznego silnika Sulzer 3AL 25/30 do symulacji wpływu zmian obciążenia i uszkodzeń na niestacjonarność prędkości kątowej

Dereszewski M.

Zeszyty Naukowe Akademii Morskiej w Gdyni

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2013

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nr 81

28--37

PL

W artykule przedstawiono wykorzystanie uproszczonego modelu matematycznego silnika Sulzer 3AL 25/30 napędzającego prądnicę prądu przemiennego, do przewidywania wpływu zmian obciążenia i prędkości obrotowej na zmiany wartości prędkości kątowej chwilowej wału korbowego. Uproszczony model dynamiczny silnika nie uwzględnia wpływu drgań skrętnych wału na wartość prędkości kątowej. Założono, że ze względu na dużą sztywność wału korbowego silnika trzycylindrowego wpływ drgań skrętnych można pominąć. W celu uzyskania przebiegów siły stycznej dla różnych obciążeń wykorzystano wartości ciśnienia pomierzone indykatorem elektronicznym. Badania wykonano na stanowisku silnika średnioobrotowego 3AL 25/30. Przeprowadzono symulacje pracy silnika bez obciążenia oraz przy obciążeniach N = 50 kW, 100 kW, 150 kW oraz 200 kW. Wyniki badań przedstawiono na wykresach porównawczych, które pozwalają na wnioskowanie diagnostyczne. Symulacje modelowe stanów uszkodzenia silnika pomagają przy ocenie i klasyfikacji przebiegów rzeczywistych niestacjonarności prędkości kątowej pomierzonych za pomocą enkodera fotooptycznego ETNP–10.

EN

The paper presents utilization of simplified mathematical model of engine Sulzer 3AL 25/30 for prediction of impact of failure, load and rotational speed changes at fluctuation of instantaneous angular speed of the crankshaft. Simplified model omit torsional vibrations impact at angular speed instantaneous value. It was assumed than due to stiffness of three – cylinder engine shaft, angular deviations due to torsional vibrations are not considered. In order to obtain the value of tangential force at different loads, real values of in – cylinder pressure, measured by electronic indicators, were taken. Experiment was carried out at Sulzer 3AL 25/30 test bed. During experiment, measurements at loads of idle run, 50 kW, 100 kW, 150 kW and 200 kW were conducted. Results were presented in form of comparison graphs, which let to build diagnostic conclusions. Simulations are useful for evaluation and classification of real runs of instantaneous angular speed, measured using optical encoder ETNP-10.

15

Model based prediction of the crankshaft instantaneous angular speed fluctuations

Dereszewski M., Charchalis A.

Journal of KONES

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2013

|

Vol. 20, No. 1

55--61

EN

The paper presents results of the calculation, based on simplified engine model, aimed on prediction of IAS (Instantaneous Angular Speed) of the crankshaft fluctuations under faulty engine condition. Gas forces were calculated basing on results of in-cylinder pressure measurements which were used as inputs to the dynamic model. Mass forces were calculated basing on technical particulars of the engine Sulzer 3Al 25/30.Measurements of the incylinder pressure 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 model utility for diagnostic prediction of the engine behavior, 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 enable to fuel leakage simulation. The engine was run out at load 250 kW what is around 65% of nominal. Results of all measurement were smoothed in order to eliminate a noise using SG (Savitzky – Golay) filter. Results of fault condition modeling were compared with healthy engine model and with results of in -cylinder pressure diagrams, in order to create a map of deviations from normal condition.

16

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

|

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.

17

Evaluation of combustion of engine Sulzer 3AL 25/30 by measuring of crankshaft angular speed

Dereszewski M., Polanowski S.

Combustion Engines

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2013

|

R. 52, nr 3

346--350

EN

Analysis of Instantaneous Angular Speed (IAS) of the crankshaft is considered as one of non intrusive and effective method of detection of combustion quality deterioration. In this paper are presented results of experimental verification of high pressure fuel system’s malfunction detecting, using optical encoder for IAS recording. The implemented method relay on comparison of measurement results recorded under healthy and faulty condition of the engine. Elaborated dynamic model of angular speed variations enables to build templates of engine behavior. Data processing of raw angular speed signal was noise decomposition in way of implementation of Savitzky-Golay filter. Measured signal of faulty and healthy conditions were compared and value of difference was taken as an indicator of malfunction.

PL

Analiza chwilowej prędkości kątowej wału korbowego silnika jest uważana za efektywną i nieinwazyjną metodę wykrywania pogorszenia jakości procesu spalania w cylindrze. W artykule zaprezentowano wyniki weryfikacji eksperymentalnej wykrywania uszkodzenia systemu paliwowego wysokiego ciśnienia w oparciu o pomiar prędkości kątowej enkoderem optycznym. Zastosowana metoda polega na porównaniu wyników pomiaru na silniku sprawnym oraz z symulowanym uszkodzeniem. Model matematyczny ruchu obrotowego wału pozwala na tworzenie teoretycznych wzorców krzywej zmian prędkości dla różnych symulacji uszkodzeń. Dekompozycja zakłóceń sygnałów pomierzonych została przeprowadzona z wykorzystaniem filtrów Savitzky’ego-Golaya. Wartość różnicy pomiędzy wygładzonymi przebiegami prędkości chwilowej w stanie bez i z symulacją uszkodzenia stanowi wskaźnik uszkodzenia.

18

Badania możliwości pozyskiwania informacji diagnostycznej o pracy silników okrętowych i układów napędowych na podstawie dyskretnie mierzonej prędkości kątowej

Dereszewski M.

Zeszyty Naukowe Akademii Morskiej w Gdyni

|

2012

|

nr 76

5--13

PL

W artykule opisano metodę weryfikacji i ewaluacji wykorzystania funkcji zmian prędkości kątowej wału korbowego oraz jej pochodnej do monitorowania zakłóceń równomierności pracy cylindrów. Badania wykonano na stanowisku silnika średnioobrotowego 3AL25/30. Pomiar prędkości chwilowej zrealizowano za pomocą tarczy ze 180 szczelinami i głowicy fotooptycznej. Przebiegi prędkości kątowej wyznaczono, opierając się na pomiarze czasu przejścia szczelin i odkłócono, wykorzystując filtry Savitzky’ego-Golaya. Przeprowadzono symulacje niesprawności, których wyniki wskazują na możliwość wykorzystania przebiegów prędkości kątowej wału do oceny stanu technicznego. Zebrane dane mogą być obrabiane na statku, na podstawie formuł zapisanych w programie MS Excel. W artykule przedstawiono plan badań mających na celu określenie przydatności bieżącego pomiaru chwilowej prędkości obrotowej wału, a następnie analizy porównawczej z wartościami wzorcowymi, do celów diagnostycznych.

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, long term recording and archive of values is enabling by modern programmable logic controllers. Measurement of IAS (Instantaneous Angular Speed) is done using optical sensor and toothed disc. 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 cannot replace Main Effective Pressure measurement or vibration monitoring, but tool for early warning. When a signal of 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.

19

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.

20

Experimental method of evaluation of diagnostic value of the angular speed discrete signal from free end of the crankshaft

Charchalis A., Dereszewski M.

Diagnostyka

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2012

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nr 3(63)

17-22

EN

The paper presents the method of the experimental way of finding the answer whether IAS (Instantaneous Angular Speed) 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 the 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, the healthy engine run was recorded and malfunction of engine's fuel system were simulated. The malfunction was fuel leakage from high pressure line and bad condition of the injector. The IAS was measured and recorded by perforated disc mounted at the shaft and photooptic sensor.

PL

W artykule zaprezentowano eksperymentalną metodę sprawdzenia czy chwilowa prędkość kątowa wału korbowego jest nośnikiem informacji o jakości procesu spalania w cylindrze silnika z zapłonem samoczynnym. Eksperyment przeprowadzono na stanowisku testowym w Akademii morskiej w Gdyni, wyposażonym w silnik wysokoprężny Sulzer Al. 25/30, napędzający prądnicę. Sulzer 3Al 25/30 jest trzycylindrowym, średnioobrotowym, czterosuwowym silnikiem o mocy maksymalnej 400 kW, przy prędkości obrotowej 750 obr./min. W celu oceny przydatności sygnału prędkości kątowej do celów diagnostycznych przeprowadzono pomiary na silniku w stanie wzorcowym bez usterek, a następnie powtórzono pomiary symulując usterki systemu paliwowego. Symulowane usterki to przeciek na pompie wtryskowej oraz zły stan techniczny wtryskiwacza. Do pomiarów prędkości kątowej zastosowano laserowy czujnik fotooptyczny.