Abstract: In a certain model, under the condition of idling and turning on the air conditioning compressor, the car appeared obvious low frequency noise. When the air conditioning compressor was turned off, the noise disappeared. Through the collection of the vibration and noise data, data post-processing and filter playback analysis, it was confirmed that the low frequency noise in the car was from the compressor. Through the hardware analysis of air conditioning system, investigation and rectification verification, it was confirmed that the pressure pulsation of the refrigerant in the compressor suction and exhaust lines was the key factor. Finally, a plan to increase the expansion chamber in the compressor exhaust pipe, and reduce the inner diameter of suction pipe was confirmed. The subjective interior noise optimization was obvious. The objective data showed that the main order noise of the compressor in the car was reduced by 10.1 dB(A).

Key words: Idle speed; Compressor; Low frequency noise; Air Conditioning pipeline; Pressure pulsation; Noise optimization

摘要： 某车型在怠速开空调压缩机吸合工况下，车内出现明显的低频噪声，空调压缩机关闭 后，该噪声消失。通过采集振动、噪声数据，并对数据后处理及滤波回放分析，确认开空调 车内低频噪声是压缩机造成的。对空调系统硬件分析、排查并整改验证，确认压缩机吸、排 气管路冷媒压力脉动为关键因素。最终确认在压缩机排气管增加扩张腔、并降低吸气管内径 的方案，主观车内噪声优化明显，客观数据显示车内压缩机主阶次噪声降低 10.1 dB(A)。

关键词: 怠速工况；压缩机；低频噪声；空调管路；压力脉动；噪声优化