This paper presents a dual fuel system for diesel-natural gas operation for a truck diesel engine, and describes results of testing and analysis of the operating characteristics of the engine. The research results show that rates of fuel consumption and fuel efficiencies are increased with this engine design, and heat consumption decreased with increasing load on the engine. The heat consumption rates at medium-high loads are lower than at light loads. At full loads, the dual fuel engine exhibits heat release in which start combustion is reduced and the following combustion is rapid. The engine is tested with an electronically controlled method to meet the requirement of engine output torque.

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.

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.

根据涡流室、主燃室中气体流动过程的质量和能量的交换关系，建立了涡流室式LPG (liquefied petrdeum gas)/柴油双燃料发动机准维燃烧模型的方程，提出了如何使两种不同性质燃料的燃烧在同一个燃烧过程中相互联系、相互作用的燃烧模型。根据模型提供的方程，对缸内燃烧过程和NOx的生成进行了模拟仿真，将其同发动机台架试验的结果进行了验证、分析和讨论。

介绍了一种新的电控共轨式燃油喷射系统。该系统根据各种液化代用燃料的特殊性质，采用电子控制技术和共轨式喷射原理，能够满足多种液化代用燃料在发动机上应用的要求。同时研究了这种系统的喷射特性，并以柴油为燃料进行了发动机台架试验，验证了系统的可行性。