Numerical Investigation Of The Flow Field In Steam Extracting Opening And Nearby Stages In Steam Turbine

By using a numerical simulation method an investigation is conducted regarding the flow fieldof steam extraction opening and nearby stages of steam turbine with the Numeca-Fine/Turbosoftware. The mathematical models and its solving method are mentioned. The structure of flowfield in the flowing parts of steam turbine,the steam extracting slot,steam collecting chamber andthe steam extracting tube is demonstrated. The results of numerical simulation is compared withexperiment and with other research results qualitatively. It is indicated that steam extraction changesthe parameter distribution in the turbine stages in radial and circumferential directions in evidence,and result in the changing of the power, the axial thrust and efficiency of turbine stages. The effectof steam extraction is varied along with the changing of working status and geometric parametersof steam extraction opening. The relative extracted steam amount has the most influence on the flowfield in all parts of steam extraction opening. Among the geometric parameters, The steam extractingslot width is the most influential one.