A pressure accumulative injection rate controllable unit Injector--PAIRCUI is proposed and developed. This unit injector is powered by fuel pressure accumulation, controlled by an electronic control unit and its injection rate is shaped by inner valves of the injector.Inherent advantages of an accumulator type unit injector have been carried out in this new design. Including structural simplicity totally flexible injection timing medium common rail pressure tolerable pump size and flow requirement. A number of decisive features have also been realized that are significant for high efficiency and low emissions of engine combustion. Including higher mean effective injection pressure (MEIP), pilot injection capability and rapid end of injection. The injection pressure is independent of engine speed but regulated upon engine load. These characteristics are beneficial in improving engine performance and fuel consumption. Installing PAIRCUI Fuel System on an engine is convenient since the injector holder is designed as a Standard- I P or S size and a conventional P or S nozzle up is incorporated as a part of the injector

利用非线性规划理论，采用Lagrange-SUMT方法建立了电控发动机全工况范围内多变量、多目标的优化模型，并在全电控柴油引燃天然气发动机上进行了应用。实验结果证明，该方法可以减少优化参数的实验量，可以在较少的实验量基础上获得最优控制MAP。发动机的NOx，碳烟排放明显优于欧洲II排放标准，经济性与原柴油机相当。

This paper presents a compound combustion technology of Premixed Combustion and "Lean Diffusion Combustion" for realizing the concept of HCCI combustion in a D I diesel engine. The premixed combustion is achieved by the technology of multi-pulse fuel injection. The start of pulse injection, injection-pulse number, injection period of each pulse and the dwell time between the injection pulses are controlled. The objective of controlling the pulse injection is to limit the spray penetration of the pulse injection so that the fuel will not impinge on the cylinder liner, and to enhance the mixing rate of each fuel parcel by promoting the disturbance to the fuel parcels. The last or main injection pulse is set around TDC. A flash mixing technology is developed from the development of a so-called BUMP combustion chamber, which is designed with some special bump rings. The combustion of fuel injected in the main injection proceeds under the effect of the BUMP combustion chamber at much higher air/fuel mixing rate than does in a conventional DI diesel engine, which leads to "lean diffusion combustion". The effects of multi-pulse injection and BUMP combustion chamber on auto-ignition, rate of heat release and engine emissions are discussed.

This paper presents a compound combustion technology of Premixed Combustion and "Lean Diffusion Combustion" for realizing the concept of HCCI combustion in a D I diesel engine. The premixed combustion is achieved by the technology of multi-pulse fuel injection. The start of pulse injection, injection-pulse number, injection period of each pulse and the dwell time between the injection pulses are controlled. The objective of controlling the pulse injection is to limit the spray penetration of the pulse injection so that the fuel will not impinge on the cylinder liner, and to enhance the mixing rate of each fuel parcel by promoting the disturbance to the fuel parcels. The last or main injection pulse is set around TDC. A flash mixing technology is developed from the development of a so-called BUMP combustion chamber, which is designed with some special bump rings. The combustion of fuel injected in the main injection proceeds under the effect of the BUMP combustion chamber at much higher air/fuel mixing rate than does in a conventional DI diesel engine, which leads to "lean diffusion combustion". The effects of multi-pulse injection and BUMP combustion chamber on auto-ignition, rate of heat release and engine emissions are discussed.

A sequential port injection, lean-burn, fully electronically-controlled compressed natural gas (CNG)/Diesel dual-fuel engine has been developed based on a turbo-charged and inter-cooled direct injection (D.I.) diesel engine. During the optimization of engine overall performance, the effects of pilot diesel and pre-mixed CNG/air mixture equivalence ratio on emissions (CO, HC, NOx, soot), knocking, misfire and fuel economy are studied. The rich and lean boundaries of the pre-mixed CNG/air mixture versus engine load are also provided, considering the acceptable values of NOx and THC emissions, respectively. It is interesting to find that there is a critical amount of pilot diesel for each load and speed point, which proved to be the optimum amount of pilot fuel. Any decrease in the amount of pilot diesel from this optimum amount results in an increase of NOx emissions, because the pre-mixed CNG/air mixture must be made richer, otherwise THC emissions would increase. However, the soot emissions remain almost unchanged at a very low level.