关键词: 动力机械工程, 混合动力汽车, 起动/发电一体化电机, 快速起动, 碳氢排放, 瞬态特性

Abstract: A test bench to simulate the rapid start of the engine with an integrated starter/generator system for the hybrid electric vehicle was presented. The transient behaviors, especially the transient hydrocarbon(HC) emissions from a inlet port fuel injected gasoline engine under rapid start at different speeds were tested to simulat the engine with ISG. The test results show that the engine demonstrates more transient behavior under the rapid start conditions at high cranking speeds than the traditional engine under the normal start conditions. The intake manifold pressure is lower when the cranking speed increases, thus the fuel metering strategy should be modified. The incomplete combustion and misfire are more liable to come into being at the first 2~9 cycles during the start process. With the increase of cranking speed, the incomplete combustion becomes more serious, leading to higher HC emissions. Under the start conditions the HC emissions can not be converted effectively by the threeway catalytic converter no matter how high the cranking speed is but its conversion rate depends on speed. When the cranking speed increases, the conversion rate decreases firstly, then increases again. For the condition of this study, the postcatalyst HC emissions appear minimum at the speed about 1000 r/min.

Key words: power and machinery and engineering, hybrid electric vehicle, integrated starter/generator, rapid start, hydrocarbon emission, transient behavior