涡轴发动机加速过程中的寿命延长优化控制

在涡轴发动机加速控制中,同时考虑发动机性能和寿命,优化加速控制策略,设计寿命延长控制.分析了加速过程中的气动稳定性、强度、燃烧稳定性以及功率等限制条件,采用序列二次规划法(SQP)优化算法进行加速控制中的燃油流量优化;根据燃气涡轮第1级静子冷却叶片温度最大值及其叶片型面与端壁的最大温差是影响发动机寿命的主要因素,采用两种寿命延长优化算法,一种是改变涡轮前温度的限制值,另一种是将涡轮前温度和动力涡轮转速同时作为优化目标,根据加权法进行折中.针对某涡轴发动机加载控制过程分别对两种寿命延长控制优化算法进行了仿真,结果表明两种方法均能有效降低涡轮前温度,并对动态性能影响较小,因此优化后的控制策略能有效延长发动机寿命.

Research on life-extending optimization control in acceleration control of turbo-shaft engine

In the acceleration control of turbo-shaft engine, life-extending control was designed by the acceleration schedule optimization by taking into consideration engine performance as well as life usage. Constraints such as aerodynamic stability margins, structural strength, combustion stability and power limitation were considered, sequence quadratic program (SQP) optimization algorithm was adopted to optimize the fuel flow of the acceleration schedule. Given that the major influential factors of engine life are the maximum temperature of the turbine first stage cooled stator and the maximum temperature difference between the airfoil and the endwall, two life-extending control methodologies were studied. The first methodology was used to modify the maximum temperature limitation to reduce the temperature of the first stage stator of turbine. The second methodology was performed by an optimization between turbine inlet temperature and shaft speed, and proper trade-offs were provided between them. Simulation of dynamic load process of a kind of turbo-shaft engine showed that both optimization methodologies can drastically reduce turbine stator temperature with minimum sacrifice in performance, then the optimized acceleration schedule can effectively prolong the life of engine.