300MW汽轮机通流改造中汽封的选择与调整

Selection and adjustment of steam seal in the flow passage transformation for 300 MW steam turbine

针对300 MW等级机组汽封运行中存在热力性能差、煤耗高、可靠性低等问题,阐述了汽轮机汽封类型和结构特点,通过实例分析了机组改造前存在的问题及处理方式,提出了汽轮机汽封改造方案和改造工艺,并对改造前后汽封调整间隙的数据进行了对比。实践证明,300 MW等级机组汽封经过改造后,减少了汽轮机端部及级间漏汽,保证了汽轮机相对内效率和运行安全,提高了机组的经济性。

Aiming at the weak thermal performance, heavy coal consumption and poor reliability of steam seal of 300 MW unit in operation, this paper demonstrates the types, structural characteristics of turbine steam seal, analyzes through examples the problems and treatments before the unit transformation, proposes transformation plan and tech- nique for turbine steam seal and compares the adjusted data of steam seal clearance before and after transformation. Practice proves the transformed steam seal for 300 MW unit reduces steam leakage at the top and between the inter- steps of turbine, guarantees the internal efficiency ratio and safe running and enhances the unit economy.