Numerical study on aerodynamic performance and flow structure of industrial steam turbine exhaust hood
                                                   YANG Xiong min, LIU Pan nian, MAO Han zhong, ZHANG Jun hui
                                                    (Hangzhou Steam Turbine Co., Ltd., Hangzhou 310022, China)

Abstract: Aiming at improving aerodynamic performance and the flow field, and reducing flow loss, a detailed research and analysis for a casting exhaust hood of an industrial steam turbine was carried out by numerical simulation. Flow mechanism and aerodynamic characteristics of the industrial steam turbine exhaust hood was revealed, and a typical flow field structure in the industrial turbine exhaust hood was proposed. A thermodynamic calculation method for characterizing the aerodynamic performance of the exhaust hood was presented, and analysis was carried out with the experimental data curve of SIEMENS. For more accuracy, calculation for the exhaust hood was coupled with three low pressure stages and the effect of addition structure on aerodynamic performance was analyzed. The results indicate that the diversified vortex motion is an important aspect of flow loss, and the addition structure in the exhaust hood can deteriorate the flow structure, but reasonable steel plates can improve the exit flow field of the industrial steam turbine exhaust hood.

Key words: industrial steam turbine; exhaust hood; flow structure; aerodynamic performance