基于动网格技术的双进/排气活塞式膨胀机动力性能研究  

Research on dynamic performance of double inlet/exhaust piston expander based on dynamic grid technology

作　　者：虞启辉[1] 耿延歧 张立从 YU Qihui;GENG Yanqi;ZHANG Licong(School of Mechanical Engineering,Inner Mongolia University of Science&Technology,Baotou 014010,China)

机构地区：[1]内蒙古科技大学机械工程学院,内蒙古包头014010

出　　处：《工程设计学报》2025年第1期132-140,共9页Chinese Journal of Engineering Design

基　　金：国家自然科学基金资助项目(52465008)。

摘　　要：采用传统的分析方法难以获得活塞式膨胀机气缸内气体的压力场、温度场和速度场分布,因此,基于CFD(computational fluid dynamics,计算流体动力学)动网格技术,研究了双进/排气活塞式膨胀机的动力性能。首先,对双进/排气活塞式膨胀机气缸内气体的非定常流动进行数值仿真,得到其压力场、温度场和速度场的瞬态分布;其次,搭建膨胀机输出功率测试平台,比较多工况下输出功率的仿真值与测试值,得出两者的误差小于5.5%,验证了仿真方法的正确性;最后,通过正交试验,分析了进气压力、进气温度对膨胀机动力性能的影响。结果表明:压缩空气进入膨胀机气缸后,气体温度先快速升高,当曲轴转角为15°后持续下降;打开排气阀后,气缸内气体的压力高于环境压力,可以对剩余压力能进行回收;提高进气温度能有效提高膨胀机动力性能,当进气压力为0.5 MPa、进气温度从273 K升高到333 K时,膨胀机的输出功率增加19.8%,气体能量利用率提高18.3%;提高进气压力,则膨胀机的输出功率逐渐增大,气体能量利用率逐渐减小,当进气温度为273 K、进气压力从0.5 MPa提高到2 MPa时,膨胀机输出功率从0.81 kW增大到3.76 kW,气体能量利用率降低15.3%。研究结果为活塞式膨胀机的性能优化提供了理论依据。The distributions of pressure field,temperature field and velocity field of gas in cylinder of the piston expander are difficult to obtain by traditional analytical methods.Therefore,the dynamic performance of the double inlet/exhaust piston expander was studied based on the dynamic grid technology of CFD(computational fluid dynamics).Firstly,the unsteady flow of gas in the cylinder of the double inlet/exhaust piston expander was simulated numerically,and the transient distributions of the pressure field,temperature field and velocity field were obtained.Secondly,the output power test platform of the expander was built,and the simulation values and test values of the output power under com,https://orcid.org/0000-0003-0796-5772 multiple working conditions were compared.The error between the two was less than 5.5%,which verified the correctness of the simulation method.Finally,the influences of inlet pressure and inlet temperature on the dynamic performance of expander were analyzed through orthogonal experiment.The results showed that after the compressed air entered the expansion cylinder,the temperature of gas increased rapidly at first,and then decreased continuously after the crankshaft angle was 15°.After opening the exhaust valve,the pressure of gas in the cylinder was higher than the ambient pressure and the residual pressure energy could be recovered.Increasing the inlet temperature could effectively improve the dynamic performance of the expander.When the inlet pressure was 0.5 MPa and the inlet temperature increased from 273 K to 333 K,the output power of the expander increased by 19.8%and the gas energy utilization rate increased by 18.3%.Increasing the inlet pressure,the output power of the expander gradually increased,and the gas energy utilization rate gradually decreased.When the inlet temperature was 273 K,and the inlet pressure increased from 0.5 MPa to 2 MPa,the output power of the expander increased from 0.81 kW to 3.76 kW,and the gas energy utilization rate decreased by 15.3%.The research resu

关 键 词：活塞式膨胀机 计算流体动力学 动网格技术 流场 正交试验 

分 类 号：TH45[机械工程—机械制造及自动化]