The performance of the engine strongly depends on the parameters of the combustion process. In compression ignition engines, the fuel injection timing has a significant influence on this process. The moment of its occurrence and its duration should be chosen so that the maximum pressure value occurs several degrees after TDC. In order to analyze the effect of the fuel injection timing on the performance of the tested two-stroke opposed-piston diesel engine, a zero-dimensional model was developed in the AVL BOOST program. Next, a series of simulations were performed based on the defined calculation points for maximum continuous power, which resulted in power, specific fuel consumption and mean in-cylinder pressure. Finally, the engine map was made as a function of the start of combustion angle.
HCCI (Homogenous Charge Compression Ignition) combustion system is now one of the most promising solutions used in piston engines. The paper presents the results of three-dimensional modeling of combustion in the single cylinder HCCI engine powered with Diesel fuel. 3D modeling was performed in AVL Fire code. The basic combustion parameters including start of the ignition (SOI), burn duration (BD), indicated pressure (pi) and nitric oxide (NO) and soot (Soot) emissions were analyzed. The modeling results show that combustion process in HCCI engine compared to a conventional engine with compression ignition is characterized by an earlier ignition (SOI) and shorter burn duration (BD). The impossibility of controlling HCCI combustion process leads to deterioration of engine performance and increased emissions of harmful exhaust gas components. Calculations showed that for the same equivalence ratio of burn mixture, uncontrolled HCCI combustion compared to a controlled combustion in engine with fuel injection operated is characterized by higher NO emission and reduced Soot emission.
This paper presents the effect of injection timing on performance and emission of a new GDI engine that has been developed from modification of a multi point fuel injection (MPFI) engine. In this study the new engine at the speed of 2500 rpm with different injection timing was simulated with KIVA-4 code. The Results are compared with those were obtained from the MPFI engine experimentally. The objective of this investigation is to find the optimum injection timing for the new engine. This paper has shown that there is an optimum interval for injection timing in which the engine performance is the highest. The results show that this optimum injection timing is 142 BTDC. Generally, the output power of the GDI engine is more than the MPFI engine at the same operating condition. It is worth nothing that for the mentioned interval, the CO is higher and the NOx emission is lower than the MPFI engine.
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In this paper the results research of the control system is presented, which allows the constant matching of the injection advance in the CI engine to varying characteristics of the controlled object, that is the engine. Quality factor of working process which is defined as a effective engine torque, is estimated on the bases of the instantaneous crankshaft torsion measurement. This concept, unlike the current system, suggest the use of efficient torque (Me) measurement to generate control quantities, which control the work process of an engine. Realization of such measurements leads to treatment of the control system as an extremal control unit (possibility of maximizing quantitative parameters) as well as an adaptive control system (possibility of unit’s reaction on changes of the parameters which influence the work process of an engine).
PL
W artykule przedstawiono wyniki badania układu sterowania, pozwalającego na ciągłe dopasowywanie się kąta wyprzedzenia wtrysku w silniku ZS do zmieniających się charakterystyk obiektu sterowania, jakim jest silnik. Wskaźnik jakości procesu roboczego zdefiniowany jako moment użyteczny silnika, szacowany jest w oparciu o pomiar chwilowego kąta skręcenia wału korbowego silnika. W zastosowanym systemie sterowania w odróżnieniu od istniejących obecnie systemów wykorzystano pomiar momentu użytecznego silnika Me do generowania wartości wielkości sterujących przebiegiem procesu roboczego silnika spalinowego. Realizacja takiego pomiaru prowadzi z jednej strony do potraktowania układu sterowania jako układu ekstremalnego (maksymalizacja wskaźników jakości procesu roboczego), natomiast z drugiej strony jako układu sterowania adaptacyjnego (możliwość reakcji układu sterowania na duże zmiany parametrów decydujących o przebiegu procesu roboczego).
The basic aim in controlling the diesel engine is to obtain a maximal effective torque for a given fuel dose with keeping at minimum toxic exhaust compounds. This postulate can be realized by matching the appropriate fuel injection timing. In this paper the research results of the control system are presented, which allow for the constant matching of the injection advance in the CI engine to the varying characteristics of the controlled object, that is the engine. Quality factor of the working process which is defined as an effective engine torque, is estimated on the base of the instantaneous crankshaft torsion measurement. This concept, unlike the currently used systems, suggest the use of efficient torque (Me) measurement to generate control quantities, which control the work process of an engine. Realization of such measurements leads to the treatment of the control system as an extreme control unit (maximizing quantitative parameters) as well as an adaptive control system (possibility of unit's reaction on high changes of the parameters influencing the work process of an engine). Combining the idea of the crankshaft torsion measurement with the idea of extreme control, a system can be designed, which makes use of torsion measurement for the adaptive control of the injection timing. The object of the research was a Diesel engine ISUZU Y17DT with electronically controlled injection pump and engine diagnostic system. Realization of the research aim required design and construction of the measurement system of the crankshaft torsion.
In the US transportation sector uses two-thirds of the country's total oil consumption. In order to minimize the consumption in this sector there is a need to investigate alternate sources of energy. Biodiesel is a possible alternative to conventional diesel. Biodiesel has many characteristics similar to petroleum based diesel and can be blended with petroleum. However biodiesel's differences in fuel properties including viscosity, bulk modulus, density, and energy content can have significant impacts on engine performance parameters like BSFC and thermal efficiency. As the availability of biodiesel fuel increases, the need for engines capable of running on various mixtures of biodiesel fuel will be required. Similar to flex-fuel ethanol vehicles, control systems for the diesel engine and aftertreatment systems will need to detect and compensate for the fuel type. In this work, a soy based B100 biodiesel fuel and an ultra low sulfur diesel fuel were tested in a high-speed direct-injection high pressure common rail four-cylinder 1.9 L diesel engine. An internally developed engine control strategy allowed real-time calibration and testing of independent control parameters including start of injection, injection duration, injection pressure, and exhaust gas recirculation (EGR) level. Both the fuels were studied under varied injection timing (0°BTDC to 12°BTDC with increments of 3°) and EGR percentages of 0 and 10%. Analysis was performed to determine the Torque, BSFC and Brake thermal efficiency.
Biofuels have the potential to diversify transportation energy sources and reduce dependence on petroleum based fuels. Of these biofuels, Methyl-ester biodiesel holds significant potential as it has many characteristics similar to petroleum based diesel and can be blended with petroleum. However, biodiesel's differences in viscosity, specific energy, oxygen content, and cetane number can cause significant changes in engine performance and emissions. Therefore, it is of prime interest to understand the combustion behaviour of biodiesel and identify key factors that contribute changes in engine performance and emissions. In this study, a 100% biodiesel fuel derived from soy and an ultra low sulphur diesel fuel were tested in a high-speed direct-injection high pressure common rail four-cylinder 1.9L diesel engine. The engine control strategy allowed real time calibration and testing of independent control parameters including start of injection, injection duration, injection pressure, and exhaust gas recirculation (EGR) level. The engine was equipped with in-cylinder pressure transducers for combustion analysis. Instrumentation for gaseous emissions detection and carbaceous particulate matter (PM) sampling was also utilized. Both the fuels were studied under varied injection timing of 0centigrade BTDC to 12 centigrade BTDC in increments of 3 centigrade, EGR percentages of 0 and 10%, and injection pressures of 400 to 900 bar. Analysis was performed to determine the rate of heat release, ignition delay, NOX and PM emissions.
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Hydrogen is expected to be one of the most important fuels in the near future for solving the problem caused by the greenhouse gases, protecting environment and saving conventional fuels. In this study, a dual fuel engine of hydrogen and diesel was investigated. Hydrogen was injected the intake port with air and diesel was injected into the cylinder. Using Electronic Gas Injector and Electronic Control Unit (ECU), the injection timing and duration was varied. In this investigation, a single cylinder, KIRLOSKAR AV1, DI Diesel engine was used. Hydrogen injection timing was fixed at TDC and injection duration was timed for 30°, 60°, and 90° crank angle. The injection timing of diesel was fixed at 23° BTDC. When hydrogen is mixed with inlet air, emissions of HC, CO and CO2 decreased without exhausting smoke while increasing the brake thermal efficiency.
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The basic aim in controlling the diesel engine is to obtain a maximal effective moment for given fuel dose with keeping of a minimum amount of toxic exhaust compounds. This postulate can be realized by matching the appropriate fuel injection commencement timing. In this paper the research of the control system is presented, which allows the constant matching of the injection advance in the CI engine to varying characteristics of the controlled object, that is the engine. Quality factor of working process which is defined as a effective engine torque, is estimated on the bases of the instantaneous crankshaft torsion measurement. This concept, unlike the current system, suggest the use of efficient torque (Me) measurement to generate control quantities, which control the work process of an engine. Realization of such measurements leads to treatment of the control system as an extremal control unit (possibility of maximizing quantitative parameters) as well as an adaptive control system (possibility of unit’s reaction on changes of the parameters which influence the work process of an engine).
PL
Podstawową funkcją celu w sterowaniu wysokoprężnym silnikiem spalinowym jest osiągnięcie maksymalnego momentu użytecznego dla zadanej dawki paliwa z zachowaniem odpowiednio niskiego poziomu toksyczności spalin. Postulat ten zrealizować można dobierając odpowiednią chwilę podania dawki paliwa definiowaną jako kąt wyprzedzenia wtrysku. W artykule przedstawiono wstępne badania układu sterowania, pozwalającego na ciągle dopasowywanie się kąta wyprzedzenia wtrysku w silniku ZS do zmieniających się charakterystyk obiektu sterowania, jakim jest silnik. Wskaźnik jakości procesu roboczego zdefiniowany jako moment użyteczny silnika, szacowany jest w oparciu o pomiar chwilowego kąta skręcenia wału korbowego silnika. W proponowanym systemie sterowania, w odróżnieniu od istniejących obecnie systemów, planuje się wykorzystanie pomiaru momentu użytecznego silnika M, do generowania wartości wielkości sterujących przebiegiem procesu roboczego silnika spalinowego. Realizacja takiego pomiaru prowadzi z jednej strony do potraktowania układu sterowania jako układu ekstremalnego (maksymalizacja wskaźników jakości procesu roboczego), natomiast z drugiej strony jako układu sterowania adaptacyjnego (możliwość reakcji układu sterowania na duże zmiany parametrów decydujących o przebiegu procesu roboczego.
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Podstawową funkcją celu w sterowaniu wysokoprężnym silnikiem spalinowym jest osiągnięcie maksymalnego momentu użytecznego dla zadanej dawki paliwa z zachowaniem odpowiednio niskiego poziomu toksyczności spalin. Postulat ten zrealizować można dobierając odpowiednią chwile podania dawki paliwa definiowaną jako kąt wyprzedzenia wtrysku. W artykule przedstawiono koncepcje budowy układu sterowania pozwalającego na ciągle dopasowywanie się kąta wyprzedzenia wtrysku w silniku ZS do zmieniających się charakterystyk obiektu sterowania, jakim jest silnik. Wskaźnik jakości procesu roboczego zdefiniowany jako moment użyteczny silnika, szacowany jest w oparciu o pomiar chwilowego kąta skrócenia wału korbowego silnika.
EN
The basic aim in controlling the diesel engine is to obtain a maximal effective moment for given fuel dose with keeping of a minimum amount of toxic exhaust compounds. This postulate can be realized by matching the appropriate fuel injection commencement timing. In this paper the concept of the control system is presented, which allows the constant matching of the injection advance in the CI engine' to varying characteristics of the controlled object, that is the engine. Quality factor of working process which is defined as a effective engine torque, is estimated on the bases of the instantaneous crankshaft torsion measurement.
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