LPG多点连续电喷发动机及车辆的排放试验研究

Experimental Study on Emission of LPG Engine and Vehicle with Electronic Multi-point Continuous Injection System

论述了电控LPG多点连续喷射系统。该系统不但可以提高发动机的动力性和经济性 ,降低排放 ,而且可以从结构和原理上避免进气管“回火”的发生。通过试验分析了空燃比和点火提前角对CO ,HC和NOx三种排放物的影响趋势 ,并从三种有害气体排放物的生成机理上分析了产生的原因及变化的规律 ;通过试验比较了发动机在不同转速下燃用汽油和LPG时的排放 ,分析了燃用LPG燃料排放降低的原因 ;最后用工况法试验循环 (ECE +EUDC)进行了车辆运行的怠速、加速、减速及等速等不同工况下的试验 ,并分析了不同工况下的排放结果。在不影响发动机的动力性及经济性的前提下 ,有害气体的排放量达到欧洲Ⅱ号法规限制的 5 0 % 。

The system of electronic controlled LPG multi-point injection was described. This system can improve engine power output and fuel economy as well as avoid the occurrence of the backfire phenomenon. The analysis on the trends of CO, HC and NO_x versus air-fuel ratio and ignition timing was made based on the experimental results. Comparison was made on emission fuelled with gasoline at different engine speed, and the reason of lower emission of LPG engine was analysed. Finally, the emission testing under ECE and EUDC modes under vehicle idle, acceleration, deceleration and steady vehicle speed was conducted. Without sacrificing vehicle power output and fuel economic, 50% lower than the EuroII limits' emission was realized.