考虑工质泄漏的大功率四缸斜盘双作用斯特林发动机性能分析

Performance analysis of high power four-cylinder oblique disk double acting Stirling engine considering working fluid leakage

滑动密封技术是四缸双作用斯特林发动机的关键技术之一,而比较精确的工质流场工程计算是前提。以计算流体力学为基础建立三阶节点分析模型,动态显示节点的温度、压强、质量和主轴扭矩等参数。采用流体仿真软件Fluent对工质流场特性进行验证,膨胀腔和压缩腔的误差都是5.2%,温度相对误差为3%和6.5%。验证采用节点分析模型是有效的。在此基础上分析了活塞和活塞杆的泄漏对主轴扭矩和净输出功的影响,结果表明同时考虑活塞和活塞杆泄漏时,主轴扭矩在247 N·m-275 N·m之间,净输出功也会减小。活塞的泄漏面积为0.008 cm^2,扭矩的波动范围235 N·m-270 N·m,振幅达到最大值35 N·m。计算结果表明可以通过工质补充系统减小泄漏造成的损失,加上工质补充之后,扭矩变化范围在247 N·m-268 N·m,能有效减小主轴扭矩的波动。

Sliding sealing technology is one of the key technologies of four-cylinder double-acting Stirling engine.The third-order node analysis model is established on the basis of computational fluid dynamics,and the parameters such as temperature,pressure,mass and spindle torque of the node are dynamically displayed.The fluid simulation software Fluent is used to verify the flow field characteristics of the working medium,the errors of the expansion chamber and the compression chamber are all 5.2%,the relative errors of the temperature are 3%and 6.5%respectively,and the effectiveness of the analytical model of the node is verified.On this basis,the influence of the leakage of the piston and the piston rod on the spindle torque and the net output work is analyzed,and the result indicates when considering the leakage of the piston and the piston rod,the torque of the main shaft is between 247 and 275 N·m,and the net output power is also reduced.The leakage area of the piston is 0.008 cm^2,the fluctuation range of the torque is 235 N·m-270 N-m,and the amplitude reaches the maximum value of 35 N-m.The results show that the loss caused by leakage can be reduced through the working medium supplement system,and after the working medium is added,the range of the torque variation is 247 N·m-268 N-m,and the fluctuation of the torque of the main shaft can be effectively reduced.