车用CNG燃气组分对发动机性能、排放影响的数值模拟

Numerical Simulation on the Influence of CNG Constituent for Vehicle on the Performance and Exhaust Emission of Engine

根据我国天然气组分随产地、季节变化的情况,选取四种具有代表性的天然气作为研究对象,通过建立单缸点火CNG发动机仿真模型,运用GT-POWER进行模拟计算。模拟结果表明:不同组分天然气对发动机动力性能影响有限;以全国平均气的有效燃油消耗为基准,四川气、东海气、凝析气的有效燃油消耗分别上升1.8%、6.5%、6.43%;以四川天然气为基准,东海气、平均气以及凝析气的CO排放分别上升16.5%、17.4%、22.6%;NO排放分别上升-0.92%、5.9%、7.5%。综合考虑动力、经济及排放特性,选用四川天然气为CNG汽车的最佳燃料。

Four typical natural gases have been selected and studied,according to the variation of natural gas composition corresponding with origins and seasons in China.According to the simulation of SI CNG engine model in GT-POWER,it＇s shown that the influence of constituent variations with different natural gases on power performance is not so much,but fuel consumption and exhaust emission are markedly influenced.Taking the fuel consumption of the natural gas with average constituent as the criterion,the fuel consumptions of the Sichuan gas,East Sea gas,and condensation gas increase by 1.8%,6.5% and 6.43% respectively.Taking the CO and NO emissions of Sichuan gas as the criterion,the CO and NO emissions of the East Sea gas,average gas,and condensation gas increase by 16.5%,17.4%,22.6%;-0.92%,5.9% and 7.5% respectively.Considering the power performance,fuel economy and emission characteristics,the Sichuan gas is the best fuel for vehicle of CNG.