Abstract: To evaluate the working flow rate of a four cylinder engine cooling system and explore the factors affecting the working flow rate, a one-dimensional analysis model of the cooling system working flow rate was constructed using GT-COOL software. Based on this model, the effects of component outlet pipe diameter, component flow resistance, and water pump performance on the working flow rate were studied. Results show that the total flow rate of the initial state of the cooling system at an engine speed of 10000 r/min is 79.8 L/min. The total flow rate of the cooling system is 83.7 L/min when the diameter of the water pump outlet pipe is 21 mm, the diameter of the small circulation outlet pipe of the thermostat is 13 mm, and the flow resistance of the oil-water exchanger and radiator is reduced by 20% respectively. The transmission ratio of water pumps and the performance of individual water pumps have a significant impact on the working flow rate of cooling systems. By improving the performance of individual water pumps and reducing the total resistance of the cooling system, the working flow rate of the cooling system is increased to 90 L/min. After verification, the measured total flow rate of the cooling system at an engine speed of 10000 r/min is 88.5 L/min, which differs from the predicted simulation value of 90 L/min by 1.5 L/min, with an error of 1.7%. This verifies the accuracy and reliability of the simulation results of the cooling system's working flow rate. The research results can provide theoretical guidance for the evaluation and improvement of the working flow rate of engine cooling systems.

Key words: engine, cooling system, working flow rate, component flow resistance, water pump performance

摘要： 为评估某四缸发动机冷却系统工作流量和探究影响工作流量的因素,采用GT-COOL软件搭建冷却系统工作流量一维分析模型,并基于该模型研究部件出水管径、部件流动阻力、水泵性能对工作流量的影响。结果表明:发动机转速10000r/min时冷却系统初始状态的总流量为79.8L/min;水泵出水管径21mm和节温器小循环出水管径13mm、油水交换器及散热器流动阻力各降低20%时冷却系统总流量为83.7L/min;水泵传动比和水泵单品性能对冷却系统工作流量的影响显著。通过提升水泵单品性能和降低冷却系统总阻力,冷却系统的工作流量增加至90L/min。经验证,发动机转速10000r/min时冷却系统总流量实测值为88.5L/min,与仿真预测值90L/min间相差1.5L/min,误差为1.7%,说明冷却系统工作流量仿真结果准确可靠。研究结果可为发动机冷却系统工作流量评估及流量提升提供理论指导。

关键词: 发动机, 冷却系统, 工作流量, 部件流阻, 水泵性能