孙振宇1,2，庞斌1,2，周鹏1,2，沈健1,2
1.内燃机可靠性国家重点实验室，山东 潍坊 261061；2.潍柴动力股份有限公司，山东 潍坊 261061
摘要：采用一维仿真、三维仿真相互提供边界的方法，研究内部废气再循环（exhaust gas recirculation，EGR）对柴油机性能的影响。以原机试验数据作为输入，建立一维仿真模型，模拟配气相位变化对换气过程的影响；将换气过程对应的进气边界赋值给三维仿真模型，模拟内部EGR对燃烧的影响，输出放热率；将放热率代入一维仿真模型，重新评估配气相位对性能的影响。仿真结果表明：内部EGR会降低泵气损失，但造成缸内热负荷增加；排气门二次开启的各缸EGR率一致性优于进气门二次开启；采用内部EGR可以在不增加NOx排放的基础上，通过提升喷油压力，达到降低油耗和碳烟的目的，并降低机油老化的风险。
关键词：柴油机；内部EGR；性能仿真
Abstract:The influence of internal exhaust gas recirculation (EGR) on the performance of diesel engine is studied using combined 1D and 3D simulation technology. A 1D simulation model is established to simulate the influence of the phase change of the distributor on the ventilation process with the original test data as input. The inlet boundary corresponding to the ventilation process is assigned to the 3D simulation model to simulate the internal EGR′s influence on combustion and calculate the heat release rate, which is substituted into the 1D simulation model to reevaluate the influence of the distribution phase on the performance. The simulation results show that internal EGR can reduce the pumping loss, but heat load in the cylinder increases. The consistency of EGR rate of each cylinder with dual opening of exhaust valve is better than that of intake valve. Internal EGR can reduce fuel consumption and smoke by increasing injection pressure without increasing NOx emission, and reduce the risk of oil aging.
Keywords:diesel engine ; internal EGR;performance simulation
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