Research On The Flow Characteristics Of The Mid-pressure Cylinder Balance Piston Steam Seal In The 600MW Steam Turbine

The steam seal transformation in the 600MW supercritical steam turbine of KangPing power plant was participated in.It was be found that the leakage of the mid-pressure cylinder balance piston steam seal in the 600MW steam turbine was large,and it reduced the economics of the unit.lt was important to research the leakage characteristics of the mid-pressure cylinder balance piston steam seal for the unit economy.The leakage characteristics of the mid-pressure cylinder balance piston steam seal in actual was researched by numerical simulation and experiment.A three-dimensional model of the the mid-pressure cylinder balance piston steam seal was established.Numerical simulation method was used to analyze the leakage characteristics of the mid-pressure cylinder balance piston steam seal,and the leakage was calculated.The result was consistent with the experimental measurement.It indicated that the model is rational.The influence of various structural parameters on the leakage was analyzed.There is a relative position between the boss and the steam seal tooth.The influence of the relative position to the leakage was analyzed.The relationship between leakage and wear was analyzed under different relative position,and the best relative position was found.It provide technical support for the installation of the steam seal tooth.The influence of tooth form to the leakage was analyzed,and more reasonable tooth was found.It provide theoretical basis for the design of steam seal tooth.The improved program of steam seal structure was proposed.lt included the tooth improvements and the installation improvements.The leakage characteristic of improvement was analyzed by numerical simulation method.The leakage of improvement was calculated.The influence of the improvement structure for the steam turbine was analyzed from the design,machining and working.It demonstrated that the improvement was feasible.The impact of leakage for the coal consumption was analyzed.According to the operation of unit 2,it can be saved 200,000 yuan.