关键词: 发动机, 冷却系统, 工作流量, 部件流阻, 水泵性能

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