关键词: 天然气发动机；正丁烷；燃烧特性；台架试验

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