EGR冷却器换热特性研究

Research on Heat Exchange Characteristics of EGR Cooler

废气再循环(exhaust gas recirculation)是降低柴油机尾气排放中的氮氧化物(NOX)以及降低天然气发动机爆震的一项非常有效的措施,在废气再循环中,EGR冷却器是其中的一个关键零部件。本文在发动机试验台架上研究了EGR冷却器进水流量、EGR冷却器进水温度、EGR冷却器进气温度以及EGR冷却器进气流量对EGR冷却器出气温度的影响,以便为发动机匹配最合适的EGR冷却器。试验结果表明:水流量变化对EGR冷却器的出气温度不敏感,发动机无法使用减少或者增加水流量的方法来降低或者提高EGR冷却器的出气温度;EGR冷却器的进水温度每增加1℃,EGR冷却器的出气温度升高0.9℃;EGR冷却器的进气温度每升高10℃,EGR冷却器的出气温度升高0.7℃;EGR冷却器的进气流量每升高10kg/h,EGR冷却器的出气温度升高1.2℃。

Exhaust gas recirculation is a very effective measure to reduce nitrogen oxides(NOX)in diesel exhaust emissions and reduce natural gas engine knock.In exhaust gas recirculation,EGRcooler is one of the key components.This paper studies the influence of EGRcooler’s coolant inlet flow rate,EGRcooler’s coolant inlet temperature,EGRcooler’s gas inlet temperature and EGRcooler’s gas inlet flow rate on the EGRcooler outlet temperature on the engine test bench,in order to best match the engine Suitable EGRcooler.The test results show that:the coolant flow change is not sensitive to the outlet temperature of the EGRcooler,and the engine cannot use the method of reducing or increasing the coolant flow to reduce or increase the outlet temperature of the EGRcooler;every time the inlet coolant temperature of the EGR cooler increases by 1℃,The outlet temperature of the EGRcooler increases by 0.9℃;the gas inlet temperature of the EGRcooler increases by 10℃,the outlet temperature of the EGRcooler increases by 0.7℃;the gas inlet flow rate of the EGR cooler increases by 10kg/h,the outlet temperature of the EGRcooler increased by 1.2℃.