Study On Remodel Design And Aerodynamic Performance Of Guiding Cascades Of Steam Turbine

The development level of turbomachinery,which plays an emportant role in the economic development of countries and construction of military around the world. Most of the domestic industry sectors such as energy, power generation, transportation, aviation,spaceflight, navigation, etc., are all kinds of works of turbomachinery.It has experienced more than 60 years that the steam turbine industry has been from introduced completely to retrofit design after absorbing. Fanally, it has its own independent mode of patent step by step. With the development of our country economy high speed stability and energy shortage problem,improve the efficiency of steam turbine is one of the aims for scientific research workers.Guid cascade of steam turbine was used as a prototype, using software UG radial shrinkage blade and the blade was constructed, which had the very high precision of blade surface geometry. The AUTOGRID was used to differentiate the structured grid model of high quality software. Finally, ANSYS-CFX commercial software was used in aerodynamic performance of numerical analysis for prototype and retrofit cascade.The prototype of supercritical guide blade was retrofitted before and after, different sweep Angle of guide vane was constructed, to research the influence of guide blade aerodynamic performance for axial from technology. After retrofitting, before and after blade sweep Angle of 20 ° respectively and- 20 °, prototype cascade sweep Angle of 0 °, provided with CFD numerical simulation software CFX for prototype and retrofit cascade aerodynamic performance simulation. Results show that sweepforward cascade obviously increased the low momentum fluid accumulation in the upper and lower side wall angle area, the side wall of lateral secondary increased the secondary flow losses. Angle area accumulation of low energy fluid decreased, and reduced the side wall of lateral secondary flow loss, which made the whole guide cascade port air flow more smoothly.Tinkering with prototype oriented cascade meridian plane, numerical results show that provided by CFX software, retrofited for radial shrinkage blade aerodynamic efficiency was higher, the distributions of aerodynamic parameters along the blade height and more uniform.Radial shrinkage blade of low momentum fluid within the upper wall boundary layer radial motion, but also weaken the suction side export adverse pressure gradient on the negative impact of the flow.