Numerical Simulation Study On Optimization Of Steam Turbine Exhaustpassage

The exhaust passage of the steam turbine is an important part of the steam turbine.The exhaust passage includes a section of passage from the final exhaust port to the inlet of the condenser inlet.It collects the working fluid discharged from the last stage of the turbine and allows the working fluid is used for deceleration and diffusion and guided into the condenser.Therefore,when the vacuum level of the condenser throat is constant,as the pressure distribution capacity of the exhaust passage becomes stronger,the unit’s enthalpy drop will rise,but the exhaust passage is complex inside and a whirlpool movement will occur,resulting in an exhaust cylinder energy loss.The reasons for affecting the performance of exhaust passages are complex and diverse.From the perspective of internal components,this article explores the flow field characteristics of existing exhaust passages of steam turbines.By considering the influence of each component,we study how to improve the performance of exhaust passages and have achieved an improvement in generating units.Efficiency,energy saving and emission reduction purposes.In this paper,a 600 MW steam turbine unit model is used to divide the internal components into five models.Through numerical simulation,the flow field characteristics of the five models are analyzed and studied.The influence and influence degree of different components are studied in detail.The basis is to make multiple optimization plans,compare the optimal plans for numerical simulation,and finally apply the plan to the project,performance comparisons before and after optimization,and analyze the economy.The calculation results show that low-pressure steam extraction pipelines,low-pressure heaters,and small engine exhaust all break the flow field evenly,and supporting pipes and stiffeners will break the flow field vortex and make the outlet speed more uniform.Therefore,the internal components of the exhaust passage will convection.The impact of the field,so each component should be comprehensively considered in the study,when adding the appropriate baffles,the flow field is clearly uniform,applied to the project,the front and rear state of the condenser before and after the installation of the baffle unit is consistent below,the overall heat transfer coefficient increases,and the average condenser pressure decreases.Provides the basis for the follow-up study of the exhaust passage.The comparison between the simulation results and the actual engineering data shows that installing an appropriate guide can break the internal vortex,make the flow field more reasonable,improve the overall heat transfer coefficient of the condenser,and ultimately improve the heat transfer performance of the condenser and reduce The purpose of steam pressure.