替代燃料对发动机动力性及排放的影响

The Effect of Alternative Fuels on Engine Power and Emissions

在能源问题日益突出的当下,使用天然气等替代燃料是有效的解决方法之一.文中研究了以天然气为主的替代燃料对发动机的动力性和排放的影响.建立某型号发动机GT仿真模型并进行校准,在此模型上分别使用汽油、天然气、Gr和G25作为燃料模拟仿真,对比分析发动机的性能.并针对以CNG为燃料时发动机的动力性提出优化方案.结果表明,以CNG为燃料的发动机在动力性方面与汽油机有差距,在转矩上相差最大达21.9%,功率上相差最大达19.8%.但在排放方面更有优势,NOx排放最大减少81.66%,CO排放最大减少26.67%.不同成分的天然气燃料对CNG发动机的动力性和排放影响明显,Gr相比G25转矩和功率最大提高29.11%,但G25相比Gr在NOx的排放上最大降低66.75%,CO的排放最大降低99.61%.以CNG为燃料时优化之后发动机动力性提升明显,在3200 r/min和4000 r/min转速下转矩提高了4.8%.

With the increasingly prominent energy issue,the use of alternative fuels such as natural gas is one of the effective solutions.This article examines the impact of natural gas-based alternative fuels on engine dynamics and emissions.A GT model engine simulation model was established and calibrated.Gasoline,natural gas,Gr,and G25 were used as fuel simulations on this model,respectively,to compare engine performance.And to propose an optimization plan for the engine’s power when CNG is used as fuel.The results show that CNG-fueled engines have a gap in terms of dynamics with gasoline engines,with a maximum difference of 21.9%in torque and a maximum difference of 19.8%in power.However,it has more advantages in terms of emissions.The maximum NOx emissions are reduced by 81.66%,and the maximum CO emissions are reduced by 26.67%.Different components of natural gas fuel have significant impact on CNG engine’s power and emissions.Compared with G25,Gr has a maximum increase of 29.11%in torque and power.However,G25 has a maximum reduction of 66.75%in NOx emissions compared with Gr,and CO emissions are reduced by up to 99.61%.When CNG is used as fuel,the engine power is optimized and improved significantly.The torque is increased by 4.8%at 3200 r/min and 4000 r/min.