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.

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。

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.

近十年来, 由于能源和环保的要求, 火花点火天然气发动机以高效、低污染燃烧的优点正在迅速发展。为了分析和研究这种发动机的燃烧过程, 预测多种参数变化对性能的影响, 建立了火花点火式天然气发动机的准维燃烧模型。根据倒拖发动机的实验结果, 对缸内紊流的衰减和产生进行了模化, 提出了缸内紊流强度计算的方法。试验表明, 模型的计算值和试验值具有很好的一致性。该模型计算精度高、工程应用方便, 为缸内燃烧过程分析、性能预测提供了一种有效的工具。

介绍了火花点火式变组分煤层气发动机的主要设计过程。通过发动机台架试验，在不同点火提前角、不同甲烷浓度和不同压缩比时对该发动机的起动、怠速稳定性和排放特性进行了分析。结果表明，变组分煤层气发动机起动、怠速稳定，带负荷工作可靠。通过控制合适的空燃比，可以适应甲烷浓度大范围变动的煤层气燃烧。未燃HC和CO排放量随负荷、甲烷浓度增加而降低；;NOx排放量随负荷、甲烷浓度增加而增加。