变组分生物质燃气发动机循环变动试验研究

摘要

In view of the poor stability and large cyclic variations in biogas engines, experimental studies on variable component biomass ( CH4-H2-CO-CO2 ) engine operation stability were carried out on a 337 cc displacement spark ignition engine by employing bottled gases which includes CH4 , H2 and CO2 to simulate actual biogas.The influences of fuel and CO2 components on combustion stability were investigated, and an influence law of cyclic changes in the engine with changes in the fuel component was developed.The results show that engine operation stability is influenced strongly by fuel component.Under low H2 content conditions, CO2 content has a dominant effect on combustion stability.An increase in CO2 content could induce an increase in cyclic variation and lead to partial burning under special circumstances .However, under high H2 content conditions, the effect of CO2 content on combustion weakens gradually, and the effect is not obvious when the H2 content reaches 50%.Under constant H2 content conditions, variations in CH4 and CO contents have no obvious influence on biogas combustion.%针对生物质燃气发动机运转稳定性差、循环变动大的问题，采用瓶装气体模拟实际生物质燃气的方法，在一台火花点火发动机上进行了变组分生物质燃气（CH 4－H2－CO－CO2）发动机的循环变动试验研究，分析了各可燃组分及CO2含量变化对发动机工作稳定性的影响，给出了燃料组分变化对发动机循环变动的影响规律。结果表明，燃料组分变化对燃烧稳定性的影响情况有较大差异：在当量比固定且燃料组分中H2含量较少时，CO2含量对燃烧稳定性起支配作用，CO2含量的增加导致循环变动增加，在个别条件下导致部分燃烧的发生；随H2含量增加，CO2含量对燃烧的影响作用逐渐减弱，当H2含量达到50％时CO2含量对燃烧的影响作用已不明显；H2含量固定时，CH4及CO含量的变化对混合燃料的燃烧并无明显影响。