F级联合循环汽轮机冷态启动优化研究

Study on Cold Start-Up Optimization of F-Class Combined Cycle Turbine

描述了联合循环中低压合缸机组汽轮机的冷态启动过程,通过有限元方法模拟了中低压转子在暖机过程中的温度场分布,系统研究了金属凝结换热对转子轴心升温速率的影响。研究发现,提高汽轮机背压可以显著缩短低速暖机时间,背压越高,暖机速度越快。进一步提出了提高轴封供汽阶段的机组背压,利用轴封汽辅助暖机的设想。研究成果可为中低压合缸结构联合循环汽轮机的冷态启动过程优化提供参考。

The cold start-up process of combined cycle steam turbine with IP-LP combined casing is described,and the temperature field of IP-LP rotor is simulated using finite element method.The influence of condensation heat transfer on heating rate of shaft centerline is investigated.The simulation results show that the warm-up time can be reduced remarkably by raising the back-pressure of turbine,in other words,the higher the back-pressure is,the less the warm-up time will be.Furthermore,it is proposed that the unit can be warmed up utilizing the shaft seal steam after raising the back-pressure.The research results can provide reference for cold start-up optimization of combined cycle turbines with IP-LP combined casing.