Investigation of the comprehensive performance of turbine stator cascades with heating endwall fences

The study of wet steam two-phase flow is particularly important for the improvement of steam turbine efficiency and optimization of the design of a cascade channel. For White cascade, an endwall fence was designed and heated in the cascade. Eulerian-Eulerian model based on the finite volume method was imposed to analyze the aerodynamic performance, dehumidification performance, entropy production and enthalpy drop of the cascade for different positions and heating strengths of the endwall fence. The analysis indicated that the dehumidification performance can be improved by installing the endwall fence close to the cascade outlet but that doing so slightly deteriorates the aerodynamic performance. Moreover, higher heating intensity is costlier while providing a decreasing benefit; thus, it is necessary to select reasonable heating intensity. By comparison, an optimum design scheme is obtained that can improve the stage efficiency, operational safety and overall work capacity of the unit while reducing the energy loss. Moreover, compared with the original case, the average outlet wetness, total pressure loss and entropy production of the cascade can be lessened by 43.4%, 2.0% and 2.0%, respectively, while the enthalpy drop is raised by approximately 3.9%. These research results can serve as a reference for turbine passage design. (C) 2019 Elsevier Ltd. All rights reserved.