燃气轮机涡轮后机匣温度场及应力分析

对某型燃气轮机涡轮后机匣加强筋发生断裂的事故进行了温度场和热应力的有限元分析计算，计算表明，涡轮后机匣表面突遇过冷而产生的巨大温度应力是造成加强筋断裂的根本原因。本文还对涡轮后机匣表面安装隔热附件后的情况进行了分析计算，计算表明，在遇到温度发生突变的不利情况下，隔热附件对涡轮后机匣能起到有效的保护作用。

Temperature-field and Stress Analysis of a Gas Turbine Rear Casing

A finite element analysis and calculation of temperature fields and thermal stresses was conducted in connection with the rupture failure of a reinforced rib on a gas turbine rear casing. The results of calculation indicate that the root cause of the reinforced rib rupture consists in the huge temperature stresses triggered by an abrupt temperature drop on the turbine rear-casing surface. An analytical calculation was performed of the situation when a thermal insulation layer was provided on the rear-casing surface. Relevant calculations show that in the case of an unfavorable condition arising from an abrupt change in temperature the thermal insulation layer can effectively protect the turbine rear casing.