汽车空调系统制冷剂流动噪声研究及性能优化

Research and Performance Optimization of Refrigerant Flow Noise in Automotive Air Conditioning System

汽车制冷系统运行初始阶段,从冷凝器到膨胀阀之间的管路存在气液两相流动,由此会产生气泡群且伴随着高频异响.从减少气液两相流动及消耗声能2个角度设计并验证了3种不同的消声方案,即加装小孔消音器,阀球与阀体接触处开孔以增加阀的动作值和加装扩张式消音器.通过焓差实验台将室外/内侧温度分别控制在35/27℃.通过瀑布图和主观感受对实验进行评价,实验结果表明,小孔消音器消除了9 kHz以上的高频异响;阀球与阀体接触处开孔效果最优,8 kHz以上基本消除,6～8 kHz前半段消除,后半段噪声值降低,在人体可接受范围内;采用扩张式消音器可以消除掉高频异响,主观感受优于原状态.

During the initial operation phase of the automobile refrigeration system, there is a two-phase flow in the pipeline from the condenser to the expansion valve, generating bubble groups accompanied by high-frequency abnormal sound. This paper designs and verifies three different muffling schemes from the perspectives of reducing two-phase flow and dissipating sound energy. They are the installation of silencer, valve ball opening to increase the valve action value and the installation of orifice muffler. The outdoor/interior temperatures were controlled at 35/27℃. The experimental results show that the orifice muffler eliminates the high-frequency abnormal noise above 9kHz. The valve ball has the best perforating effect, basically eliminating above 8kHz, eliminating the first half of 6-8kHz and reducing the decibel value of the second half, which is acceptable to the human body. Expansion muffler can eliminate high frequency abnormal noise, and the subjective feeling is better than the original state.