多级无油活塞式压缩机多场耦合特性分析研究

Analysis of multi-field coupling characteristics of multi-stage oil-free piston compressors

为提升无油活塞式压缩机的可靠性,满足轨交车辆对压缩机可靠性要求,通过对新研制的无油活塞式压缩机开展热动力学多场耦合分析研究,明确了吸、排气过程中的压力分布特性、不同曲柄角对应的温度分布特性、压缩机工作过程中的气体速度分布和流量特性,呈现了压力和温度发生较明显变化的区域,展示了气体速度场中的涡流分布情况。结果表明,压力波动主要存在于吸、排气口附近,最大压力约为0.51 MPa,其余部分压力均布;压缩机排气时的内部温度均匀分布,在吸、排气口附近存在最大温度梯度约为50 K;运用分析结果对压缩机的设计、可靠性优化进行理论指导,对试制样机在排气压力在1.1 MPa的工况下进行了1000 h疲劳试验,试验全程中重点部位的振动峰值为9.2 mm/s、温度峰值为148℃,满足了规定工况下保证长时间稳定性能运行的要求。研究结果可为无油活塞式压缩机的优化设计提供参考。

In order to improve the reliability of oil-free piston compressors and meet the reliability requirements of rail transit vehicles,a thermal dynamic multi-field coupling analysis study was conducted on a newly developed oil-free piston compressor in a certain country.The pressure distribution characteristics during the suction and exhaust process,temperature distribution characteristics corresponding to different crank angles,gas velocity distribution and flow characteristics during compressor operation were clarified,a region with significant changes in pressure and temperature was presented,and the distribution of eddy currents in the gas velocity field was exhibited.The results show that pressure fluctuations mainly exist near the suction and exhaust ports,with a maximum pressure of about 0.51 MPa,and the rest of the pressure being evenly distributed.The internal temperature during compressor exhaust is uniformly distributed,with a maximum temperature gradient of about 50 K near the suction and exhaust ports.The analysis results were used to provide theoretical guidance for the design and reliability optimization of the compressor.A 1000 hour fatigue durability test was conducted on the prototype under an exhaust pressure of 1.1 MPa.The vibration peak at the key parts of the test was 9.2 mm/s,and the temperature peak was 148℃,which meets the requirements of ensuring long-term stable operation under specified working conditions.The research results can provide reference for the optimization design of oil-free piston compressors.