CPR1000核电汽轮机高压缸甩负荷工况热应力及变形分析

Thermal Stress and Deformation of High Pressure Casing of CPR1000 Nuclear Steam Turbine in the Load Rejecton Condition

以CPR1000核电半速汽轮机高压缸为研究对象,根据机组高压缸甩负荷工况蒸汽参数曲线及热平衡说明书,采用第三类边界条件对高压缸进行有限元计算,分析了甩负荷工况前后高压缸的温度场、热应力、接触压力、变形量等强度指标。研究结果表明:甩负荷时,高压缸内外壁面温差降低,甚至出现负温差(-8℃),主要温差形式为轴向温差;高压缸在启动阶段进入额定负荷及甩负荷阶段出现应力峰值,峰值为211. 5和116 MPa,但在甩负荷时中分面接触压力有所增加,汽密性较好。

With a CPR 1 000 nuclear half-speed steam turbine as an object,the finite element method is used to calculate the temperature field、stress field、contact pressure and deformation of HP casing in load rejection condition by using the third boundary condition according to the steam parameter curves of the load rejection condition and heat balance diagram. Results show that: the temperature difference between the inner surface and the outer surface of HP casing is reduced,and even negative temperature difference occurs during the load rejection condition,with the main temperature gradient in the axial direction. Two stress peaks occur in the rated load and the load rejection stage,respectively. The contact pressure of the flange joint surface increases in the load rejection condition and the leak-tightness is very good.