In order to solve the problems of the poor economic performance and structural safety of the steam turbine unit, the Yangtze Petrochemical Thermal Power Plant decided to carry out flow passage transformation in No. 5 steam turbine. To improve the efficiency of the steam turbine, the following measures were taken: adjusting the flow layout, replacing the nozzle group, optimizing the blade form, improving the efficiency of the wheel, reducing the leakage loss and so on. In terms of safety and reliability, the main measures were rotor replacement, blade strength design, welded steel diaphragm, low-pressure last stage blade against water corrosion, etc. Through the flow passage transformation, No. 5 steam turbine could run safely and stably, each index reached the performance guarantee value of the project, and the coal consumption of the single unit power generation under various working conditions met the governmental standard. |