航空油冷发电机过热保护设计的研究及分析

Research and analysis on overheating protection design of aviation oil-cooled generator

发电机热场分布对过热保护构件失效影响显著,是其优化设计中应重点考虑的参数。借助ANSYS软件中Fluent稳态压力求解器和湍流模型对故障模式下发电机内部热场分布进行仿真,获得主发电机定、转子和壳体循环油路热场分布;在此基础上,调整部分关键部位熔点及材料软化温度,优化热脱扣保护装置设计方案,实现电机过热保护,该方案已成功应用于某飞机,且已通过试验和试飞验证。结果表明:仿真热场结果与实际工况下的温度场分布一致,电机出口油温达到260℃时绝缘衬套软化,导致电机腔体内发生漏油,当发电机绝缘衬套软化温度提高至350℃,可有效避免发电机烧损。

The thermal field distribution of generator is of a significant effect on the failure phenomenon of the overheat protection component,which is a key parameter to be considered in the optimization design.The thermal field distribution of the motor under fault mode is simulated by using the steady-state pressure solver and turbulence model in ANSYS software.The thermal field distribution of the stator,rotor and shell circulating oil circuit is obtained.On this basis,the material melting point and softening temperature of key components are adjusted,and design scheme of thermal trip protection device is optimized,which will be helpful to realize the protection of motor overheating,which is successfully applied to a certain aircraft and verified through experiments and flight tests.The results show that the simulation is consistent with the actual temperature field distribution.The simulation results of the thermal field distribution of the generator and low melting point alloy show that the insulation liner softens as the oil temperature at the outlet of the motor reaches 260℃leading to oil leakage in the motor cavity.Meanwhile,with the softening temperature of generator insulation liner increases to 350℃,generator burnout is significantly prevented.