不同发动机排量和循环工况对整车综合油耗的影响

Influence of Different Engine Displacement and Cycles on Vehicle Fuel Consumption

为了研究不同发动机排量以及不同循环工况对整车综合油耗的影响,以一款1.0L三缸直喷增压发动机(TGDI)为研究对象,分别将其增缸扩容为1.33 L和1.4 L,建立整车模型,运行NEDC、WLTC和CLTC循环,计算整车综合油耗。仿真结果表明,在搭载该发动机的两款整车模型运行过程中对于不同循环工况的影响:WLTC循环油耗最高,CLTC循环油耗次之,NEDC循环油耗最低。造成油耗差异的原因是WLTC循环平均车速高,克服阻力需求的功率高,导致油耗最高,NEDC与CLTC平均车速差异不大,但CLTC车速变化频繁,发动机负荷更大,导致油耗更高。对于排量的影响:排量每增加0.1L,NEDC循环油耗上升0.10~0.13L/100km,WLTC循环油耗上升0.04~0.08L/100km,CLTC循环油耗上升0.10~0.14L/100km。WLTC循环油耗上升较小的原因是在循环运行区域,3款发动机油耗率差异较小。

To investigate the influence of different engine displacements and cycles on vehicle fuel consumption, the displacement of a 1.0 L TGDI engine was increased to 1.33 L and 1.4 L, then vehicle models were built to run NEDC, WLTC and CLTC cycles with those 3 engine maps. The simulation results show that:(1) The fuel consumption order of cycles was WLTC> CLTC> NEDC, for WLTC’s mean velocity is higher than other cycles, CLTC has a more frequently changing velocity comparing to NEDC.(2) For each0.1 L increase of displacement, the increase of fuel consumption in NEDC was 0.10~0.13 L/100 km, CLTC was 0.10~0.14 L/100 km, WLTC was 0.04~0.08 L/100 km, which is minimum. Because the BSFC points used by WLTC cycle differed slightly among the three engines.