冷却系统对发动机缸内性能参数的影响

The Effect of Cooling System on Performance Parameters of Engine Cylinder

针对某国产1.5 L发动机,基于GT-Suite建立了发动机、燃烧室和冷却系统的耦合仿真模型,研究不同转速、负荷率和冷却液温度对发动机缸内性能参数和关键零部件热负荷的影响。结果表明,缸内压力和温度等性能参数与转速和负荷率呈正比,但随着冷却液温度的升高呈先增加后降低的趋势。气缸盖等关键零部件在冷却液温度满足散热条件下,仍然处于较高的热负荷状态,当转速6 000 r/min,负荷率50%时对应的最高温度为542.6 K。故为降低气缸盖热负荷,不仅应使冷却液温度满足散热要求,还应对燃烧室形状进行优化。

In this paper,the effects of different speeds,load rates and coolant temperatures on the engine performance parameters and the thermal load of significant components are studied with a coupling simulation model of engine,combustion chamber and cooling system,which is established based on GT-Suite for a domestic 1.5 L engine.The results show that the performance parameters,such as cylinder pressure and temperature are indirect proportion to the speed and load rate.But with the increase of coolant temperature,these parameters increase first and then decrease.The significant components such as cylinder head are still in a high heat load with the radiation being satisfied.The maximum temperature is 542.6 K when the speed is 6 000 r/min and load rate is 50%.Therefore,not only the coolant temperature should satisfy the cooling requirements,but also the shape of the combustion chamber should be optimized to reduce heat load of the cylinder head.