A set of compressed natural gas (CNG) multi-point direct injection system of spark-ignited engines and the corresponding measurement and data acquisition systems were developed in this paper. Based on different inject...A set of compressed natural gas (CNG) multi-point direct injection system of spark-ignited engines and the corresponding measurement and data acquisition systems were developed in this paper. Based on different injection modes, the mixture formation and combustion of CNG low-pressure direct injection (LPDI) engines were studied under varying factors such as air/ fuel ratio, injection timing. Meanwhile, three-dimensional simulations were adopted to explain the mixture formation mechanisms of CNG low-pressure compound direct injection (LPCDI) mode. On the basis of test results and simulation of the mixture homogeneous degree, the conception of injection window was proposed, and the LPCDI mode was proved to be more beneficial to the mixture concentration stratification formation in cylinder under lean-burning conditions, which resulted in effective combustion and stability.展开更多
The population which could not access to electricity was around 1.2 billion in 2010 and is distributed in many low developing countries. With the increase in the population and the economic growth in those countries, ...The population which could not access to electricity was around 1.2 billion in 2010 and is distributed in many low developing countries. With the increase in the population and the economic growth in those countries, waste generation is growing rapid especially for the organic and the plastic, and the uncontrolled waste disposal is becoming more serious issues to manage it. The interest on waste to energy is growing by the above drivers. This research was carried out for aiming to the real world adaption at the minimum cost of the pyrolysis oil from waste biomass in a diesel engine, mainly for electricity generation. The proposal of the appropriate adaptable blend ratio was the major scope rather than the optimization of the engine parameters. For the sake of it, the pyrolysis oil of the waste biomass was produced from a gasification pilot plant in Japan and blended with biodiesel at minimum effort. A small single cylinder diesel engine （direct injection） was used for the experiment with regard to full load power-output, exhaust emissions and fuel consumption.展开更多
Based on the analysis of the advantages of the Natural Gas Engine with Direct Injection （NGEDI） and the state of the art of the research in this area, the authors point out that, the NGEDI with high pressure is one ...Based on the analysis of the advantages of the Natural Gas Engine with Direct Injection （NGEDI） and the state of the art of the research in this area, the authors point out that, the NGEDI with high pressure is one potential selection and will have a good application prospects. Through investigation experiment and simulation results, the key techniques are put foreword for deployment of the NGEDI and some solutions are given.展开更多
Research on dual-fuel(DF)engines has become increasingly important as engine manufacturers seek to reduce carbon dioxide emissions.There are significant advantages of using diesel pilot-ignited natural gas engines as ...Research on dual-fuel(DF)engines has become increasingly important as engine manufacturers seek to reduce carbon dioxide emissions.There are significant advantages of using diesel pilot-ignited natural gas engines as DF engines.However,different combustion modes exist due to variations in the formation of the mixture.This research used a simulation model and numerical simulations to explore the combustion characteristics of high-pressure direct injection(HPDI),partially premixed compression ignition(PPCI),and double pilot injection premixed compression ignition(DPPCI)combustion modes under a low-medium load.The results revealed that the DPPCI combustion mode provides higher gross indicated thermal efficiency and more acceptable total hydrocarbon(THC)emission levels than the other modes.Due to its relatively good performance,an experimental study was conducted on the DPPCI mode engine to evaluate the impact of the diesel dual-injection strategy on the combustion process.In the DPPCI mode,a delay in the second pilot ignition injection time increased THC emissions(a maximum value of 4.27g/(kW·h)),decreased the emission of nitrogen oxides(a maximum value of 7.64 g/(kW·h)),increased and then subsequently decreased the gross indicated thermal efficiency values,which reached 50.4%under low-medium loads.展开更多
A certain amount of ammonia reducer were directly injected into the 4102BZLQ Diesel engine's combustion chamber when the combustion temperature decreases to 1573-1073K, NOx generated could be reduced to 1.11g/(kW&...A certain amount of ammonia reducer were directly injected into the 4102BZLQ Diesel engine's combustion chamber when the combustion temperature decreases to 1573-1073K, NOx generated could be reduced to 1.11g/(kW·h). Based on PRF combustion mechanism, NO was tested by using the heavy-duty diesel engine test cycle of ESC thirteen conditions[1], the ammonia spray angle and amount were tested and optimized in different conditions. The test results show that the thermal efficiency of Diesel engine does not decrease while NO exhaust decreases.展开更多
Heavy fuel aviation piston engines(HF-APEs)refer to the engine using fuels with high flash point,such as kerosene or light diesel.Here technique specifications of some classical foreign HF-APEs(Hirth3503,Zanzottera 49...Heavy fuel aviation piston engines(HF-APEs)refer to the engine using fuels with high flash point,such as kerosene or light diesel.Here technique specifications of some classical foreign HF-APEs(Hirth3503,Zanzottera 498)are introduced.Recent progress and trend of fuel injection,fuel ignition,working cycle,intake charging,thermal management and electronic control of HF-APE are compared and summarized.Emphases are put on the technological difficulties,solutions and development tendency in the design,retrofitting and manufacturing of HF-APE aiming to provide references for the research of related area and the development of prototype HF-APE in China.展开更多
As the practicability of a hydrogen-fueled economy emerges, intermediate technologies would be necessary for the transition between hydrocarbon fueled internal combustion engines and hydrogen powered fuel cells. In th...As the practicability of a hydrogen-fueled economy emerges, intermediate technologies would be necessary for the transition between hydrocarbon fueled internal combustion engines and hydrogen powered fuel cells. In the present study, the hydrogen engine efficiency and the load control are the two main parameters that will be improved by using the combined operation of in-cylinder direct fuel injection (DI) and port fuel injection (PFI) strategies to obtain maximum engine power outputs with acceptable efficiency equivalent to gasoline engines. Wide open throttle (WOT) operation has been used to take advantage of the associated increase in engine efficiency, in which the loads have been regulated with mixture richness (qualitative control) instead of volumetric efficiency (quantitative control). The capabilities of a 3D-CFD code have been developed and employed to simulate the whole engine physicochemical process which includes the hydrogen injection through the intake manifold (PFI) and/or the hydrogen DI in the engine compression stroke. Conditions with simulated PFI, PFI + DI and DI have been analyzed to study the effects of mixture preparation behaviors on the hydrogen ignition and its flame propagation inside the engine combustion chamber. Numerically, the CFD code has been intensively validated against experimental engine data which provided remarkable agreement in terms of in-cylinder pressure history evaluation.展开更多
As one of the most important actuators for gasoline direct injection technology,common rail systems provide the requested rail pressure for fuel injection.Special system characteristics,such as coupled discrete-contin...As one of the most important actuators for gasoline direct injection technology,common rail systems provide the requested rail pressure for fuel injection.Special system characteristics,such as coupled discrete-continuous dynamic in the common rail system,limited measurable states,and time-varying engine operating conditions,impel the combination of advanced methods to obtain the desired injection pressure.Therefore,reducing the pressure fluctuation and satisfying engineering implementation have become noteworthy issues for rail pressure control(RPC)systems.In this study,the benchmark problem and the design specification of RPC proposed by 2018 IFAC E-CoSM Committee are introduced.Moreover,a common rail system model is provided to the challengers,and a traditional PI control is applied to show the problem behaviors.Finally,intermediate results of the challengers are summarized briefly.展开更多
基金Supported by National High Technology Research and Development Program ("863" Program) of China (No.2008AA11A114)
文摘A set of compressed natural gas (CNG) multi-point direct injection system of spark-ignited engines and the corresponding measurement and data acquisition systems were developed in this paper. Based on different injection modes, the mixture formation and combustion of CNG low-pressure direct injection (LPDI) engines were studied under varying factors such as air/ fuel ratio, injection timing. Meanwhile, three-dimensional simulations were adopted to explain the mixture formation mechanisms of CNG low-pressure compound direct injection (LPCDI) mode. On the basis of test results and simulation of the mixture homogeneous degree, the conception of injection window was proposed, and the LPCDI mode was proved to be more beneficial to the mixture concentration stratification formation in cylinder under lean-burning conditions, which resulted in effective combustion and stability.
文摘The population which could not access to electricity was around 1.2 billion in 2010 and is distributed in many low developing countries. With the increase in the population and the economic growth in those countries, waste generation is growing rapid especially for the organic and the plastic, and the uncontrolled waste disposal is becoming more serious issues to manage it. The interest on waste to energy is growing by the above drivers. This research was carried out for aiming to the real world adaption at the minimum cost of the pyrolysis oil from waste biomass in a diesel engine, mainly for electricity generation. The proposal of the appropriate adaptable blend ratio was the major scope rather than the optimization of the engine parameters. For the sake of it, the pyrolysis oil of the waste biomass was produced from a gasification pilot plant in Japan and blended with biodiesel at minimum effort. A small single cylinder diesel engine （direct injection） was used for the experiment with regard to full load power-output, exhaust emissions and fuel consumption.
文摘Based on the analysis of the advantages of the Natural Gas Engine with Direct Injection （NGEDI） and the state of the art of the research in this area, the authors point out that, the NGEDI with high pressure is one potential selection and will have a good application prospects. Through investigation experiment and simulation results, the key techniques are put foreword for deployment of the NGEDI and some solutions are given.
基金Project(2017YFE0102800)supported by the National Key R&D Program of ChinaProject(19JCYBJC21200)supported by the Tianjin Natural Science Foundation,China。
文摘Research on dual-fuel(DF)engines has become increasingly important as engine manufacturers seek to reduce carbon dioxide emissions.There are significant advantages of using diesel pilot-ignited natural gas engines as DF engines.However,different combustion modes exist due to variations in the formation of the mixture.This research used a simulation model and numerical simulations to explore the combustion characteristics of high-pressure direct injection(HPDI),partially premixed compression ignition(PPCI),and double pilot injection premixed compression ignition(DPPCI)combustion modes under a low-medium load.The results revealed that the DPPCI combustion mode provides higher gross indicated thermal efficiency and more acceptable total hydrocarbon(THC)emission levels than the other modes.Due to its relatively good performance,an experimental study was conducted on the DPPCI mode engine to evaluate the impact of the diesel dual-injection strategy on the combustion process.In the DPPCI mode,a delay in the second pilot ignition injection time increased THC emissions(a maximum value of 4.27g/(kW·h)),decreased the emission of nitrogen oxides(a maximum value of 7.64 g/(kW·h)),increased and then subsequently decreased the gross indicated thermal efficiency values,which reached 50.4%under low-medium loads.
基金Sponsored by the Hunan Science and Technology Agency Science Research Program 09(2009GK3091)the Hunan Provincial Education Department Science Research Program 09(09C1138)
文摘A certain amount of ammonia reducer were directly injected into the 4102BZLQ Diesel engine's combustion chamber when the combustion temperature decreases to 1573-1073K, NOx generated could be reduced to 1.11g/(kW·h). Based on PRF combustion mechanism, NO was tested by using the heavy-duty diesel engine test cycle of ESC thirteen conditions[1], the ammonia spray angle and amount were tested and optimized in different conditions. The test results show that the thermal efficiency of Diesel engine does not decrease while NO exhaust decreases.
文摘Heavy fuel aviation piston engines(HF-APEs)refer to the engine using fuels with high flash point,such as kerosene or light diesel.Here technique specifications of some classical foreign HF-APEs(Hirth3503,Zanzottera 498)are introduced.Recent progress and trend of fuel injection,fuel ignition,working cycle,intake charging,thermal management and electronic control of HF-APE are compared and summarized.Emphases are put on the technological difficulties,solutions and development tendency in the design,retrofitting and manufacturing of HF-APE aiming to provide references for the research of related area and the development of prototype HF-APE in China.
文摘As the practicability of a hydrogen-fueled economy emerges, intermediate technologies would be necessary for the transition between hydrocarbon fueled internal combustion engines and hydrogen powered fuel cells. In the present study, the hydrogen engine efficiency and the load control are the two main parameters that will be improved by using the combined operation of in-cylinder direct fuel injection (DI) and port fuel injection (PFI) strategies to obtain maximum engine power outputs with acceptable efficiency equivalent to gasoline engines. Wide open throttle (WOT) operation has been used to take advantage of the associated increase in engine efficiency, in which the loads have been regulated with mixture richness (qualitative control) instead of volumetric efficiency (quantitative control). The capabilities of a 3D-CFD code have been developed and employed to simulate the whole engine physicochemical process which includes the hydrogen injection through the intake manifold (PFI) and/or the hydrogen DI in the engine compression stroke. Conditions with simulated PFI, PFI + DI and DI have been analyzed to study the effects of mixture preparation behaviors on the hydrogen ignition and its flame propagation inside the engine combustion chamber. Numerically, the CFD code has been intensively validated against experimental engine data which provided remarkable agreement in terms of in-cylinder pressure history evaluation.
基金the National Nature Science Foundation of China(Nos.61790564,61803173)the Program for Natural Science Foundation of Jilin Province(No.20190103047JH).
文摘As one of the most important actuators for gasoline direct injection technology,common rail systems provide the requested rail pressure for fuel injection.Special system characteristics,such as coupled discrete-continuous dynamic in the common rail system,limited measurable states,and time-varying engine operating conditions,impel the combination of advanced methods to obtain the desired injection pressure.Therefore,reducing the pressure fluctuation and satisfying engineering implementation have become noteworthy issues for rail pressure control(RPC)systems.In this study,the benchmark problem and the design specification of RPC proposed by 2018 IFAC E-CoSM Committee are introduced.Moreover,a common rail system model is provided to the challengers,and a traditional PI control is applied to show the problem behaviors.Finally,intermediate results of the challengers are summarized briefly.
