基于Kriging模型的斯特林发动机密封腔压力多目标优化

摘要

In order to enhance the sealing property of piston rod dynamic seal structure of Stirling engine and reduce the wear loss of seal structure,taking a type of Stirling engine as an object,the Kriging models of wear performance and sealing property of piston rod sealing ring were established,in which the response values are the wear loss of sealing ring,and contact stress between sealing ring and piston rod,the design variable is the sealing chamber pressure.To regard the minimum value of wear loss and maximum value of contact stress as the optimization objects,to take the established Kriging models as the objective functions,the optimization model of the sealing chamber pressure was constructed.The optimum value of the sealing chamber pressure was sought by the NSGA-Ⅱ algorithm,and the concrete value was 6.95 MPa.The test results obtained by sealing performance test device indicate that the optimum sealing chamber pressure can guarantee the piston rod sealing performance,and also reduce the wear loss of sealing ring effectively.%为提高斯特林发动机活塞杆动密封结构的密封性能,减少密封结构的磨损量,以某型斯特林发动机为对象,将其密封腔压力作为优化变量,分别以动密封环的磨损量,密封环与活塞杆的接触应力为响应指标,构建活塞杆密封环的磨损性能和密封性能Kriging模型;以提高密封结构密封性能,降低密封结构磨损量为优化目标,以构建的Kriging模型为目标函数,建立斯特林发动机密封腔压力多目标优化模型.使用NSGA-Ⅱ算法对密封腔压力值进行多目标寻优,得到斯特林发动机密封腔压力的优化值为6.95 MPa.利用斯特林活塞杆密封性能试验平台进行试验,结果表明:优化的密封腔压力在保证活塞杆密封结构密封性能的同时,能够有效减少密封环的磨损量.