This paper reports the development of a new prechamber combustion system of the 2190T natural gas engine. The experimental results show that the new combustion system is reliable and practical, and that the performance of the engine is greatly improved due to stable ignition and fast flame propagation in prechamber and high burning rate and short burning period in main chamber.

This paper describes the development of a natural gas engine with a prechamber. The comparison between a conventional gas engine and the engine with the prechamber is given. The testing results show that the new combustion system is reliable and practical. The performance of the engine, compared to the conventional gas engine, is greatly improved due to stable ignition and quick flame propagation in the prechamber and a high burning rate and short burning period in main chamber. The analyses of the combustion processes and lean combustion potential in the engine are further discussed.

Spark ignition natural gas engines with prechamber, having high thermal efficiency and low exhaust emissions, have been developed due to energy resouces and air pollution problems in recent ten years. A lot of significant results on experiment have been given, but the reports on combustion model were few seen so far. This paper discribles a quasidimensional combustion model for the engines with prechamber. A simulation method for calculating turbulent intensity in cylinder and a submodel for jet orifices between two chambers are put forword. It showed by testing that calculated data showed good general agreement with the correspanding experimental values.

用傅立叶变换红外光谱法对木质生物质在280-380℃水中的直接液化产物进行了研究。研究表明，木质生物质的液化可以分为2个阶段，即纤维素类和木质素类的液化；最终液化产物官能团受温度的影响不大；最终液化产物是复杂的混合物，含有烃、醛、酮、酚和酯等各类化合物。

Liquefied alternative fuels offer great potential benefits in reducing exhaust emissions and improving fuel economy of automotive engines. In order to achieve the best performance of the engine running with such fuels, it is critical to have an appropriate fuel system. In the present work, a new electronically controlled common-rail injection system has been specially designed and tested for the direct injection of liquefied alternative fuels, since a conventional pump-line-injector injection system in the conventional diesel engine was not suitable for the purpose. Experimental work has been carried out to examine and improve matching of the fuel injection system on a new fuel injection pump test bench. The preliminary engine bench test has demonstrated that this arrangement meets the requirement for the operating characteristics of a fuel injection system in a direct injection diesel engine operating with dimethyl ether (DME).