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1

Possibility of obtaining diagnostic information about the ships engine fuel injection system condition based on the analysis of characteristics of heat release

Witkowski Kazimierz

Journal of KONES

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2019

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Vol. 26, No. 3

249--256

EN

Marine engines are very complex technical objects, having many important functional systems, which include, inter alia, injection system, characterized by high unreliability. In this system, there may be different types of defects (damage) that affect the engine parameters, including specific fuel consumption, as well as failures endanger the safety of the ship. The indicator diagrams and analysis of indicated parameters have limited utility in the diagnosis of damages of marine engine, although this is a method commonly used in operational practice. To achieve greater diagnostic effectiveness, when, based on indicator diagrams, are calculated and then the characteristics of heat release is analysed - net of heat release characteristics and the intensity of the heat release, it was demonstrated. This procedure is particularly effective in the diagnosis of damages of marine diesel engine injection system components. It has been shown that the characteristics of heat release contain information about the condition of the injection systems, which enable to diagnose their failures. This is shown on the example of a clogged nozzle holes (their carbonizations). The obtained results allowed selecting the diagnosis symptoms, useful in detecting these faults in the injection system, from the characteristics of heat release: net heat release (Q) and intensity of heat release (q). The object of the research was typical marine medium speed engine Sulzer A25/30.

2

Influence of cetane-detergent additives into diesel fuel with RME content increased to 10% on the parameters of indicator diagrams and rate of heat release in a diesel engine

Stanik Winicjusz, Cisek Jerzy

Combustion Engines

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2019

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R. 58, nr 4

226--235

EN

This publication is the next part of the article “The influence of cetane-detergent additives in diesel fuel increased to 10% of RME content on energy parameters and exhaust gas composition of a diesel engine”. The cause-effect analysis of the phenomena related to the impact of 3 additive packages used in diesel oil with RME content increased to 10% (compare to standard diesel fuel with 7% of RME) was described. The basis for the analysis of the impact of the tested fuels on energy parameters and composition of exhaust gases were the parameters of indicator diagrams and heat release parameters. It was found that the first set of additives affects the delay of auto-ignition of fuel and kinetic fuel combustion speed only at low engine loads. In this range of engine operation the NOx concentration in the exhaust gas is low and besides there is a large of EGR. The second additive package was operated at high engine loads but its impact on the lower self-ignition delay was quantitatively small. Therefore, in the third packet of additives, the amount of additives used in the second packet was doubled. Then a satisfactory shortening of the self-ignition delay and reduction of the max rate of kinematic heat release was achieved as a reason of a reduction of NOx concentration in the exhaust up to 8% (compared to the reference fuel).

3

Assessment methods of the basic parameters of the combustion process in reciprocating internal combustion engines

Lejda Kazimierz, Warianek Michał

Combustion Engines

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2019

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R. 58, nr 4

21--26

EN

The article presents selected methods of assessing the basic parameters of the combustion process, as well as assessing the usability and limitations of the methods used to determine the initiation and the end of the combustion process in reciprocating internal combustion engines. The methods considered are based on data contained in real, developed indicator diagrams. Basic thermodynamic assumptions and the scope of application of the combustion process evaluation method based on the actual work cycle of a combustion engine prepared in a double logarithmic scale were discussed. The article also mentions the application of the following methods: a direct pressure comparison method in the cylinder, the comparison of the first pressure derivative in the cylinder, logarithmic derivative meth-od of pressure change in the cylinder, the method of the polytropic index, method of the first derivative of the polytropic index and the method of constant values of the polytropic index. The article presents the advantages and disadvantages of the research of our methods.

4

Analysis of the uniqueness of the combustion process of the Perkins 1104D-E44TA engine in dual-fuel operation powered by natural gas and diesel fuel

Kurczyński Dariusz, Warianek Michał, Łagowski Piotr

Combustion Engines

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2019

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R. 58, nr 2

156--164

EN

The paper presents the results of the research on the uniqueness of the combustion process in the Perkins 1104D-E44TA engine already equipped with a Common Rail injection system, and then adapted on an engine test stand to dual-fuel operation. The result of the combustion process is an indicator diagram. The combustion process in the cylinder of the tested engine was evaluated by determining the uniqueness indicators of subsequent operating cycles, such as: the uniqueness indicator for the maximum pressure of the operating cycle, the uniqueness indicator for the mean indicated pressure, the uniqueness indicator for the indicated diagram and the uniqueness indicator for the partial indicator diagram. The conducted tests and the analysis of the results showed the impact of dual-fuel power supply of the tested engine on the combustion process, as compared to supplying the engine only with diesel fuel, for which it has been optimized.

5

Parameters of the combustion process in the Fiat 0.9 TwinAir engine, working under selected load characteristics and powered with LPG and CNG gas fuels

Kurczyński D., Łagowski P., Warianek M.

Zeszyty Naukowe Instytutu Pojazdów / Politechnika Warszawska

|

2018

|

z. 1/115

81--90

EN

The article presents the results of research on the combustion process of the Fiat 0,9 TwinAir engine powered by petrol, and LPG and CNG gas fuels. In order to use gas fuels for powering the internal combustion piston engines rationally, the essential knowledge about basic combustion process parameters of gas fuels in engine combustion chamber is required. This is dictated by the significant differences in physiochemical indicators of gas fuels in comparison with petrol fuels. In case of powering the internal combustion engine with a LPG gas fuel the maximum achieved pressure values in the cylinder are much higher in comparison with it been fuelled by petrol. The air and LPG gas mixture combustion process is much more intense, and achieved values of pressure increases in the cylinder while fuelling with this fuel were the biggest in comparison with the engine being fuelled with petrol or CNG gas. This causes an increase in the piston-connecting rod system load through the gas forces which are applied directly on to the piston head, it also causes an increase of the engine thermal load. While the engine was powered by the Compressed Natural Gas CNG, the combustion process was taking the largest amount of time in nearly every given range of engine speed-load conditions. The high delay of the initiation of the combustion process was also observed for the air and CNG fuel mixture.

PL

W artykule przedstawiono wyniki badań procesu spalania w silniku Fiat 0,9 TwinAir zasilanego benzyną bezołowiową 95 oraz paliwami gazowymi LPG i CNG. W celu racjonalnego wykorzystania paliw gazowych do zasilania tłokowych silników spalinowych niezbędna jest znajomość podstawowych parametrów procesu spalania tych paliw w komorze spalania silnika. Proces spalania mieszanki składającej się z powietrza oraz gazu LPG przebiega gwałtownie, a osiągane wartości przyrostów ciśnienia w cylindrze w przypadku zasilania silnika tym paliwem były największe w porównaniu do uzyskanych przy zasilaniu silnika benzyną lub gazem CNG. Zasilając silnik gazem LPG osiągnięto najwyższe wartości ciśnienia maksymalnego w cylindrze silnika. Powoduje to wzrost obciążenia układu korbowo-tłokowego siłami gazowymi oddziaływującymi bezpośrednio na denko tłoka oraz znaczne obciążenie cieplne silnika. W przypadku zasilania silnika sprężonym gazem ziemnym CNG proces spalania przebiegał najdłużej przy zadanych warunkach prędkościowo obciążeniowych silnika. Wykazano również znaczne opóźnienie rozpoczęcia procesu spalania ładunku składającego się z powietrza i gazu CNG.

6

Indicator curves of the Perkins 1104-E44TA dual-fuel diesel oil and natural gas engine

Kurczyński D., Łagowski P., Warianek M.

Zeszyty Naukowe Instytutu Pojazdów / Politechnika Warszawska

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2018

|

z. 2/116

131--142

EN

The introduction of ever more stringent exhaust emission standards and the necessity of searching for new energy sources caused searches for fuels for powering combustion engines enabling a reduction of their harmful influence on the environment. Natural gas is one such fuel, with the use of which for powering piston combustion engines increasing in recent time. The use of this fuel for powering combustion engines permits a reduction of their harmful influence on the environment. The article describes the properties of natural gas as fuel for supplying piston combustion engines, a characteristic of an engine test bed with a Perkins 1104D-E44TA automatic ignition engine equipped with a Common Rail supply system, adapted for dual-fuel operation using diesel fuel and natural gas. The purpose of the article is the presentation of the influence of dual-fuel operation of the tested engine on pressure curves in the engine cylinder. During test bed studies, the engine operated according to an external speed characteristic. The study was conducted powering the engine with diesel fuel and under dual-fuel operation using diesel fuel and natural gas. The described pressure curves were presented and shown in diagrams. Based on these, selected characteristic combustion process parameters were determined, such as maximum cylinder pressure values pmax and maximum cylinder pressure increase values (dp/dα)max.

PL

Wprowadzanie coraz bardziej rygorystycznych norm emisji spalin oraz konieczność poszukiwania nowych źródeł energii spowodowało poszukiwanie paliw do zasilania silników spalinowych, pozwalających na zmniejszenie ich szkodliwego oddziaływania na środowisko. Jednym z takich paliw jest gaz ziemny, którego zastosowanie w ostatnim czasie do zasilania tłokowych silników spalinowych stale wzrasta. Stosowanie tego paliwa do zasilania silników spalinowych pozwala na zmniejszenie ich szkodliwego oddziaływania na środowisko. W artykule opisano właściwości gazu ziemnego jako paliwa do zasilania tłokowych silników spalinowych, scharakteryzowano stanowisko badawcze z silnikiem o zapłonie samoczynnym Perkins 1104D-E44TA wyposażonym w układ zasilania Common Rail, przystosowanym do dwupaliwowego zasilania olejem napędowym i gazem ziemnym. Celem artykułu było przedstawienie wypływu dwupaliwowego zasilania badanego silnika na przebiegi ciśnienia w cylindrze silnika. Podczas badań hamownianych silnik pracował według zewnętrznej charakterystyki prędkościowej. Badania przeprowadzono zasilając silnik olejem napędowym oraz dwupaliwowo olejem napędowym i gazem ziemnym. Wyznaczone przebiegi ciśnienia przedstawiono i porównano na rysunkach. Na ich podstawie określono wybrane charakterystyczne parametry procesu spalania takie jak maksymalne wartości ciśnienia pmax w cylindrze oraz maksymalne wartości przyrostu ciśnienia w cylindrze (dp/dα)max.

7

The influence of the compression ratio error and the pressure error at the beginning of compression on the heat release characteristic calculated based on indicator diagram marine diesel engine

Witkowski K.

Journal of KONES

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2018

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Vol. 25, No. 1

457--463

EN

In the operational diagnostic of marine engines, the analysis of indicator diagrams is important. In addition to analysing changes in the values of indicated parameters, should be aimed to oriented broader analysis, including the determination on the basis of experimental indicator diagram of heat release characteristics during the combustion process. In the diagnostics of piston engines, including marine engines, special interest arouses to use single-zone model based on indicator diagrams as a source of information. There are calculated heat release characteristics: net heat release (Q) and intensity of heat release (q). The article discusses the impact problem the characteristics of heat release calculated based on experimental indicator diagram various errors – the compression ratio error and the pressure error at the beginning of compression. Based on the results of own research we analysed the impact on the characteristics of heat release the compression ratio error and the pressure error at the beginning of compression. The effect of the errors on the course of characteristics q and Q, to the typical marine medium speed engine Sulzer A25/30 and low speed engine Sulzer RTA 76 shown.

8

The evaluation of the Fiat 0.9 TwinAir engine powered by petrol and LPG gas work cycles uniqueness

Lejda K., Kurczyński D., Łagowski P., Warianek M., Dąbrowski T.

Journal of KONES

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2018

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Vol. 25, No. 3

323--330

EN

The article describes the test results of the uniqueness of the work cycle of two-cylinder internal combustion piston FIAT 0.9 TwinAir engine, while being powered by 95 octane petrol fuel and LPG gas. The engine was working according to load characteristics. The engine mounted on the test bench was equipped with a sequential LPG gas fuel supply system. The gas fuels differ significantly from the petrol fuels in their physiochemical properties. In order to rationally utilize gas fuels to power internal combustion engines, the knowledge about basic fuel burning process of these fuels is required. The article shows the analysis of individual engine work cycles of the technologically advanced engine in order to evaluate the influence of powering by LPG gas fuel on the rate of uniqueness of its work cycles. The measure of uniqueness of the inter-cylinder processes are the work cycle uniqueness indicators, which are as follows: the maximum work cycle pressure uniqueness indicator, the average measured work cycle pressure uniqueness indicator, the measured pressure work cycle graph uniqueness indicator and the measured pressure work cycle partial graph uniqueness. The carried out research and its analysis has shown that powering the engine with LPG gas has an influence on the engine work cycles and its uniqueness. The burning process of the mixture consisting of air and LPG gas is quicker, which has an effect on the higher speed of pressure increase rate in comparison with the engine being powered by petrol fuel. Achieved maximum in-cylinder pressure values while the engine was powered by LPG gas were higher in comparison with it being fuelled with conventional fuel. This causes an increase of the gas lads on crank-piston system, which are influencing directly the piston with higher heat load, and the thermal load of the engine.

9

The Fourier transform as a new approach of evaluating the internal combustion engine indicator diagram

Łoza Ł., Sitnik L. J.

Journal of KONES

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2017

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Vol. 24, No. 4

173--180

EN

In this paper, the authors present an introduction to the new method of evaluating the indicator diagram of internal combustion engine. For several years, it was observed that analyses of combustion processes have been hardly changed since they were conducted for the first time. At the moment, the diagrams are plotted more and more precisely owing to the new sensors and digital processors. Despite all of these high technical advantages, which were obviously unavailable in the past, theoretical approach for describing indicator diagram has not changed in significant way. Nowadays, the indicator diagrams are still evaluated very generally and are presented in much too idealistic way as a smooth curve of pressure changes, without any disturbances, which are being detected very easily now. Furthermore, it appears that performance improvements of the IC engines are in need of developing new methods for analysis and evaluation. The Fourier transform is a new way to look at the combustion process in the engines. It is basically a mathematical instrument for analysing different types of signals, which are transformed, from time domain into frequency domain. It enables identifying specific sinusoidal components of arbitrary signals and separates relevant ones from the noise. This allows one to see significant differences in two or more apparently similar signals and detect the crucial parts. If we treat pressure changes in time like a common signal, we can compute Fourier transform and see basic components of the diagram.

10

System rejestracji i analizy wykresu indykatorowego w czasie rzeczywistym

Gruca M.

Autobusy : technika, eksploatacja, systemy transportowe

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2017

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R. 18, nr 12

897--900, CD

PL

W artykule przedstawiono opis systemu rejestracji i analizy w czasie rzeczywistym wykresu indykatorowego tłokowego silnika spalinowego. Oprócz prezentowania wykresu indykatorowego w czasie rzeczywistym, system prezentuje również w czasie rzeczywistym wykresy: szybkości zmian ciśnienia, temperatury, szybkości wydzielania ciepła oraz zmian prędkości, pracy i mocy indykowanej w kolejnych cyklach pracy silnika.

EN

The article presents a description of the real-time recording and analysis system for cylinder pressure diagram of the piston internal combustion engine Moreover, the system can additionally present in real time the following diagrams: rate of cylinder pressure rise, temperature, heat release rate and changes of engine speed, IMEP, indicated power in subsequent engine cycles.

11

The problematics of determining the characteristics of heat release, based on experimental indicator diagram for diagnostic purposes

Witkowski K.

Journal of KONES

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2016

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Vol. 23, No. 1

429--436

EN

The article discusses the problem of determining the characteristics of heat release based on experimental indicator diagram for diagnostic purposes. The importance of the operational diagnosis of marine engines is the analysis of indicator diagrams was identified. In addition to analysing changes in the values of indicated, should be aimed to oriented broader analysis, including the determination on the basis of experimental indicator diagram of heat release characteristics during the combustion process. Then it is essential to choose the right model of heat release for reciprocating piston engines with direct fuel injection. In the diagnostics of piston engines, including marine engines, special interest arouses use single-zone model based on indicator diagrams as a source of information. Based on the results their own research we analysed the impact on the characteristics of heat release of simplifying assumptions in the model of heat release, including constant value adiabatic exponent. In the temperature, range 300÷2800 K waveformsκ are considered to be linearly dependent on the temperature. Based on the above, for the gas temperature from 800 K to 1850 K value of the exponent κ decreases about 3%. The effect of the value κ on the course of characteristics q and Q, to the typical marine engines was shown.

12

The issue of the indicator diagram analysis for the purpose of diagnosis of marine diesel engines

Witkowski K.

Journal of KONES

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2015

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Vol. 22, No. 2

293--298

EN

The article analyses the possibility of using the electronic type indicators, in the diagnosis of marine engines. The analysis of indicated parameters read from the indicator diagram is now widely use on ships in the diagnosis of marine engines. To make this possible, measuring indicated systems should meet a number of important requirements to be met to ensure the possibility of their diagnostic use. These include reliable determination of the top dead centre piston (TDC). The above is particularly important in in-depth analysis of indicator diagrams − calculating the heat release characteristics. The paper presents results of research on the effect of the error on the accuracy of the location of TDC (GMP) on calculated heat release characteristics. In order to demonstrate the impact positional error TDC, simulation study was conducted in which indicated diagrams was used, obtained on a medium-speed four-stroke marine engine type A25/30 and the low-speed two-stroke engine type RTA76, Sulzer Company.

13

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

Pawletko R., Polanowski S.

Logistyka

|

2014

|

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.

14

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

Pawletko R.

Journal of KONES

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2014

|

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.

15

Modelowanie silnika Stirlinga typu Alfa w programie Matlab Simulink

Chmielewski A., Gumiński R., Mydłowski T., Radkowski S.

Zeszyty Naukowe Instytutu Pojazdów / Politechnika Warszawska

|

2013

|

z. 2/93

27--38

PL

W niniejszym artykule przedstawiony został model symulacyjny I rzędu sporządzony według założeń Schmidta oraz wskazań Urieli. Odzwierciedla on podstawowe procesy zachodzące w silniku Stirliga typu Alfa. Na jego podstawie wyznaczono m.in: wykres indykatorowy zamknięty, przebiegi przemieszczeń, prędkości, przyspieszeń tłoka w funkcji kąta obrotu wału korbowego oraz zmian ciśnienia i objętości chwilowej. Stworzony model nie uwzględnia strat strumienia ciepła (m.in.: niedoskonałości regeneracji, wymiany ciepła z otoczeniem, zmienności amplitudy temperatury wsadu regeneratora na jego długości), strat energii wskutek oporów przepływu, strat energii w wyniku tarcia (np: pomiędzy tłokiem i gładzią cylindrową, strat w łożyskach, oporów ruchu w skrzyni korbowej oraz wielu innych). Aby zbilansować straty należy stworzyć model symulacyjny II rzędu, który to uwzględni. Autorzy wyrażają potrzebę dalszych prac nad bardziej zaawansowanymi modelami matematycznymi.

EN

This article shows a I-st row simulation model done according to Schmidt's assumptions and Uriel's indications. It shows the basic processes that happen in a Stirling engine of the Alpha type. Based on it among others the following things are shown: closed indicator diagram, displacement waveforms, speeds, of acceleration of the pistons in the function of the rotation angle of the crankshaft and changes of pressure and instantaneous volume. The model created does not take into consideration the loss of the heat stream (among other: imperfections of regeneration, exchanging heat with the environment, changes in the amplitudes of temperature in the regeneration input on it's length), energy loss due to resistance to flow, energy loss due to resistance to friction (among other between the piston and the cylinder lining, losses in the bearings, resistance to motion in the crankcase and many other). In order to balance the losses a II-nd row simulation model that takes this into account. The authors think it is necessary to continue work on more advanced mathematical models.

16

Charakterystyki wydzielania ciepła podczas procesu spalania oleju napędowego i estrów oleju rzepakowego

Ambrozik A., Ambrozik T., Kurczyński D., Łagowski P.

Zeszyty Naukowe Instytutu Pojazdów / Politechnika Warszawska

|

2013

|

z. 1/92

109--117

PL

W artykule przedstawiono wyniki badań silnika AD3.152 UR zasilanego paliwem mineralnym (węglowodorowym) EKODIESEL ULTRA D oraz estrami metylowymi kwasów tłuszczowych oleju rzepakowego FAME pozwalające wyznaczyć charakterystyki wydzielania ciepła podczas procesu spalania. Analiza eksperymentalnie wyznaczonych wykresów przebiegu zmiany ciśnienia paliwa w przewodzie wtryskowym i wzniosu iglicy wtryskiwacza umożliwia wyznaczenie kąta wyprzedzenia wtrysku. Wyznaczanie charakterystyk względnej szybkości wydzielania się ciepła podczas procesu spalania przeprowadzono w oparciu o eksperymentalnie sporządzone wykresy indykatorowe silnika AD3.152 UR pracującego według zewnętrznej charakterystyki prędkościowej.

EN

The paper presents the results of investigations into AD3.152 UR engine running on EKODIESEL ULTRA D mineral (hydrocarbon) fuel and FAME rapeseed oil fatty acid methyl esters. The experimental results made it possible to determine heat release characteristics in the combustion process. The analysis of experimentally obtained profiles of fuel pressure changes in the fuel rail and those of injector needle lift allowed determining the injection advance angle. The characteristics of the relative rate of heat release in the combustion process was determined on the basis of experimentally obtained indicator diagrams for AD3.152 UR engine working in the external speed characteristics.

17

Influence of clogged injector nozzles on the heat release characteristics

Pawletko R., Polanowski S.

Journal of KONES

|

2013

|

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.

18

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

|

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

19

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.

20

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.