关键词: 热交换器；水流声异响；冷却系统；气泡

Abstract: Regarding the abnormal water flow noise problem in an automobile heat exchanger, simulation experiments and other methods are used for cause analysis. Through vehicle bench tests, it is concluded based on theory and experiments that the coolant in the thermal cooling system is locally heated to generate a large number of bubbles. These bubbles enter the heat exchanger through the pipeline, causing abnormal noise in the vehicle. Finally, improvement measures are formulated according to the "source–path–response" noise, vibration, harshness (NVH) control method, and the effectiveness of this method is verified through comparative tests. The research results show that changing the position of the inlet pipe of the heat exchanger and adding a connecting pipe at the top of the thermostat base of the cooling system can discharge the bubbles in the system, which not only ensures the air conditioning heating performance but also solves the problem of water flow noise.

Key words: heat exchanger; abnormal water flow noise; cooling system; bubbles