基于功率保持的辅助动力装置引气性能计算模型

以带负载压气机辅助动力装置(APU)为对象,分析了其结构特点与工作原理,针对目前工程上常用的APU引气性能计算模型的不足,建立了基于APU与空气涡轮匹配的总体性能数学模型和负载压气机变几何部件特性插值模型。在此基础上,研究了APU功率调节规律,获得了轴功率负载、APU涡轮前温度、排气温度与负载压气机进口导叶角度之间的匹配关系,进而实现了APU全包线内和全工况下的引气性能计算。利用GTCP131-9A试验数据对模型进行了验证,结果表明:引气流量计算误差小于3%,引气压力计算误差小于4%;功率保持下的APU涡轮前温度限制值仅与轴功率负载大小有关,与进气温度无关。研究结论对于带负载压气机APU总体性能计算和调节规律设计提供了参考。 

A computation model for auxiliary power unit air bleeding performance based on flat rating

To overcome the disadvantages of the computation model for auxiliary power unit (APU) air bleeding performance in engineering, the structure characteristics and working principle of APU with load compressor were researched. A model based on the matching principle between APU and air start turbine and an interpolation model of variable geometry characteristics of load compressor were presented. On this basis, the regulation law based on APU flat rating was researched, and the relationship among the shaft power load, the APU turbine inlet temperature, the exhaust gas temperature and the inlet guide vane angle of load compressor was determined, consequently the APU bleeding performance was computed at various states in flight envelope. The model was validated with GTCP131-9A’s test data. Results showed that, the deviation of air bleeding mass flow was within 3%, while the deviation of air bleeding pressure was within 4%; in addition, the turbine inlet temperature limit at different altitudes was only related to the shaft power load, but not to the inlet temperature. The model provides a good reference for performance simulation and regulating law design of APU with load compressor.