基于一台1.5T缸内直喷高压缩比混合动力专用发动机，建立计算流体力学（CFD）模型，并通过台架试验分析发动机冷却系统优化设计对爆震及性能的影响。冷却系统采用先气缸盖再气缸体的串联冷却模式，通过对气缸体、气缸盖水套的优化设计，实现排气鼻梁区的高效热交换，可以有效抑制爆震；通过对电子水泵、EGR冷却器、水冷中冷器的优化设计，在满足高EGR率下冷却需求的同时，具有容积小、压阻低的特征，使得发动机最高有效热效率提升0.6%，非加浓最大净功率提高11%，进一步通入5%的EGR气体后，最大功率可以继续提升8%。

Based on a 1.5T gasoline direct injection（GDI） hybrid engine with high compression ratio, the effects of engine cooling system design on knock and performance were studied by establishing a computational fluid dynamics（CFD）model and bench test analysis. The system adopted a series cooling mode of cylinder head first and then cylinder block. By optimized design of the cylinder block and cylinder head water jacket, efficient heat exchange was achieved in the exhaust nose bridge area, which could effectively suppress knock. By optimized design of electronic water pumps, EGR coolers and watercooled intercoolers, the system met the cooling requirements under high EGR rates while featuring a compact size and low pressure drop. This resulted in a 0.6% increase in the engine maximum effective thermal efficiency and a 11% increase in maximum net power without enrichment. Furthermore, introducing an additional 5% of EGR gas could boost maximum power by another 8%.