空调压缩机配管空间结构振动特性分析

Vibration characteristics analysis of piping space structure for air conditioning compressor

为防止配管共振对空调系统结构造成破坏,针对某空调压缩机配管结构建立动力学分析模型,采用有限元方法对其进行模态分析,获取前14阶配管结构的固有频率以及振型,结果表明原始配管(管径为6 mm、壁厚为0.8 mm)第4、5阶固有频率与压缩机激励频率最接近,极易发生共振。随着管径及壁厚的增加,配管的固有频率与压缩机激励频率的差值均呈现增大趋势,以此为依据确定出准确的配管模型。然后对配管模型进行流体动力学计算,提取流体对管道内壁面的压力,并将提取的压力加载到管道内壁面上进行流固耦合振动分析,确定结构真实振动响应以及应力分布,据此提出空调配管结构设计建议。

To prevent the resonance damage of the piping structure for the air conditioning system, a dynamic model for an air conditioning compressor piping structure was established. The finite element method was applied for the modal analysis to get the 14 order natural frequencies and vibration modes of the piping structure. The results showed that the 4, 5 order natural frequency of the original piping (the diameter was 6 mm and the wall thickness was 0.8 mm) was close to the excitation frequency of the compressor, therefore, it was easy for the system to cause a resonance. With the increase of the pipe diameter and the wall thickness, the difference between the natural frequency of the piping and the excitation frequency of the compressor was increasing gradually. Based on this, the accurate piping model was determined. Then the piping model was hydrodynamically calculated, and the pressure of the fluid on the inner surface of the pipe was extracted. The extracted pressure was loaded onto the pipe wall to analyze the fluid solid coupling vibration, and the real vibration response and the stress distribution of the structure were determined. Accordingly, the design suggestion of the air conditioning piping was put forward.