COMPUTATIONAL FLUID-DYNAMICS ANALYSIS OF A STEAM POWER-PLANT LOW-PRESSURE TURBINE DOWNWARD EXHAUST HOOD

Computational fluid dynamics (CFD) methods are applied to the analysis of a low-pressure turbine exhaust hood at a typical steam power gener ating station. A Navier-Stokes solver, capable of modeling all the vis cous terms, in a Reynolds-averaged formulation, was used. The work had two major goals. The first was to develop a comprehensive understandi ng of the complex three-dimensional flow fields that exist in the exha ust hood at representative operating conditions. The second was to eva luate the relative benefits of a flow guide modification to optimize p erformance at a selected operating condition. Also, the influence of s imulated turbine discharge characteristics, relative to uniform hood e ntrance conditions, was evaluated. The calculations show several inter esting and possibly unique results. They support use of an integrated approach to the design of turbine exhaust stage blading and hood geome try for optimum efficiency.