Experimental and numerical study of an integrated air- and steam-cooled gas turbine vane

This paper proposes a new cooling method which integrates steam and air for gas turbine vane cooling with the aim to solve the problem of a very high thermal load at the trailing edge region of a steam-cooled gas turbine vane. The influence of coolant inlet conditions on the temperature and cooling effectiveness distribution of the experimental vane surface has been investigated in a hot wind tunnel test facility with a three-vane cascade. The test vane external aerodynamic and heat transfer were investigated experimentally and numerically. Two improved arrangement of cooling working fluid flow direction were designed to reduce the temperature gradient along the vane height. The following conclusions can be made: the thermal load at the trailing edge region is reduced for this integrated air and steam cooled gas turbine vane; the surface temperature uniformity is improved. Under an optimal thermal physical parameters of the cooling fluids, the cooling effectiveness of the trailing edge region and the leading edge region are 50% and 55%, respectively; the cooling effectiveness of the mid chord region is the highest and reaches 67%; The cooling method and structure have more influence on the cooling effectiveness compared with the cooling fluids inlet conditions.