Abstract: As energy shortages and environmental pollution problem become increasingly serious, natural gas, as an relatively ideal alternative energy, has received more and more attention. Conventional natural gas usually contains a small amount of butane, which affects the combustion characteristics of natural gas combustion. Based on the bench test of natural gas engine, this paper analyzes the changing laws of related combustion parameters through bench test data, and summarizes the influence of n-butane content on natural gas engine combustion. Studies show that for lean-burn spark-ignition natural gas engine, as the n-butane content in natural gas increases, the instantaneous heat release rate, maximum explosion pressure, and maximum pressure rise rate all increase; the 0～10% combustion duration remains unchanged, and the 10%～90% combustion duration is shortened. The combustion influence laws summarizes in this paper can guide the performance optimization direction of natural gas engine, thereby shortening development time and improving engine performance.

Key words: natural gas engine; n-butane; combustion characteristics; bench test

摘要： 随着能源短缺和环境污染问题的日益严重，天然气作为一种较为理想的替代能源，越 来越受到重视。在常规的天然气中通常会含有少量丁烷，影响天然气的燃烧特性。文章基于 天然气发动机台架试验，通过台架试验数据分析相关燃烧参数的变化规律，总结了正丁烷含 量对天然气发动机燃烧的影响。研究表明，对于稀燃的点燃式天然气发动机而言，随着天然 气中正丁烷含量升高，瞬时放热速率、最高爆发压力、最大压力升高率均得以提高；0～10% 燃烧持续期不变，10%～90%燃烧持续期缩短。文章总结的燃烧影响规律，能够指导天然气发 动机的性能优化方向，进而缩短开发时间并提高发动机性能。

关键词: 天然气发动机；正丁烷；燃烧特性；台架试验