燃气和燃氢涡轮叶栅端壁传热和气膜冷却特性OA

In the energy-transition context of"carbon peak"and"carbon neutrality",hydrogen blending and full hydrogen combustion of gas turbine have become important measures for reducing carbon emission at the source.The combustion of zero-carbon working fluid(hydrogen)leads to an increase of water vapor in combustion products and changes in thermophysical properties,thus,the aerothermal performance of downstream turbine cascades would be significantly affected.The composition changes in combustion products of different working fluids(methane and hydrogen)were studied,and the effects of gas composition and blowing ratios of 1.0,2.5 and 3.5 on the endwall heat transfer characteristics and film cooling performance of cascades were compared and analyzed.Results indicated that in the combustion products of zero-carbon working fluid,the water vapor content increased,the near-endwall specific heat capacity raised accordingly,leading to a significant increase in the local endwall heat transfer coefficient(approximately 10％)and a notable decrease in cooling efficiency(approximately 10％).With the blowing ratio being raised from 1.0 to 3.5,the degradation of endwall aerothermal performance caused by zero-carbon working fluid gradually weakened,thereafter,the increase amplitude of average heat transfer coefficient dropped from about 7.0％ to 4.5％,and the decrease amplitude of cooling efficiency reduced from about 6.0％ to 4.0％.The research results reveal the impact mechanism of combustion working fluid conversion on the aerothermal performance of downstream cascades,providing technical references for design of high-efficiency cooling layouts of hydrogen-combustion.