凸轮轴配气相位对发动机性能的影响
赵峰,肖有强,杜伟康
潍柴动力股份有限公司,山东 潍坊 261061
摘要:选用不同配气相位的凸轮轴,试验研究不同工况下凸轮轴气门重叠角、排气提前角对柴油发动机燃油消耗率、烟度排放的影响。结果表明:气门重叠角对发动机燃油消耗率影响不明显,对烟度排放的影响与发动机转速、中冷后进气压力与涡前排气压力的正向压差有关;发动机高转速时,增大气门重叠角导致烟度排放增加;当中冷后气压高于涡前气压时,增大气门重叠角能降低烟度排放;发动机中高转速时,增大排气提前角可降低燃油消耗率;发动机低转速时,减小排气提前角在一定程度上可降低烟度排放。
关键词:配气相位;柴油发动机;燃油消耗率;烟度
Effect of camshaft valve timing on engine performance
ZHAO Feng,XIAO Youqiang,DU Weikang
Weichai Power Co., Ltd., Weifang 261061, China
Abstract:The effects of camshaft valve overlap angle and exhaust advance angle on fuel consumption and smoke emission of diesel engine under different operating conditions are test and studied by selecting camshafts with different valve timing. The results show that the change of valve overlap angle has no obvious effect on the fuel consumption rate of the engine, and the smoke emission is related to the engine speed, the positive pressure difference between the intercooler and the exhaust manifold. When the engine speed is high, the valve overlap angle increasing, smoke emission increases. When air pressure of intercooler is higher than that of exhaust manifold, valve overlap angle increasing, smoke emission reduces. At middle and high engine speeds, exhaust advance angle increasing, fuel consumption reduces. At low engine speed,with exhaust advance angle reducing, smoke emission reduces.
Keywords:valve timing; diesel engine; fuel consumption rate;smoke intensity