300 MW汽轮机低压缸排汽通道优化改造

针对国产引进型300MW汽轮机低压缸排汽压力偏高的问题，对低压缸排汽通道进行优化改造，在凝汽器喉部加装均流装置，使其出口蒸汽速度分布合理，改善了凝汽器冷却管束热负荷分配，提高了传热系数。实际运行和试验证明，排汽压力降低0．5kPa以上，循环效率提高0．6％，对应的功率增加了0．3％。同时，可延长喉部支撑管和上排冷却管寿命，排汽通道优化改造取得较显著的效益。

OPTIMIZATION RETROFIT OF LOWPRESSURE CYLINDER'S EXHAUST STEAM PASSAGE FOR 300 MW STEAM TURBINE

Directing against the problem of somewhat higher exhaust steam pressure in low-pressure cylinder of imported type 300 MW steam turbine,optimization retrofit has been carried out for its low-pressure exhaust steam passage.A flow-equilibrating device is added to the throat of condenser,making the distribution of its outlet steam velocity to be reasonable,improving the thermal load distribution of condenser's cooling tube bundle,enhancing the heat transfer coefficient.Practical operation and test show that the exhaust steam pressure has lowered more than 0.5 kPa,the cycle efficiency has enhanced 0.6%,the corresponding output power has increased 0.3%,at the same time,the service life of throat-supporting pipe and upper level cooling tubes can be lengthened,the optimization retrofit of exhaust steam passage has obtained comparatively obvious effectiveness.