The objective of this study is to evaluate the potential of various grids to satisfactorily simulate the development of a cooling film, using a coupled computation that takes into account the full geometry. Detailed computations of a single row of 30 degrees round holes on a flat plate are presented for blowing ratios of 0.764, 1.01 and 1.54. The simulation results are compared well with experimental data. The two-layer model gave more accurate results but consumed much more computational time than the standard wall functions. The k-ε turbulence model with wall functions with appropriate values of + y is suitable for practical use. The results show the importance of the conjugate calculation for accurately describing the influence of the heat transfer within the cooling film.K eywords: film cooling, conjugate heat transfer, blowing ratio. CLC number: TK124 Document code: A

A hydrogen combustion turbine system has been proposed by Mitsubishi Heavy Industries, LTD. which is the Closed Circuit Cooled Topping Recuperation Cycle (CCCTR cycle) and is part of a Japanese government sponsored program WE-NET (“World Energy Network”). This cycle is composed of closed Brayton and Rankine cycles. The efficiency of this cycle is more than 60% HHV (Higher Heat Value) with a power capacity of 500MW. This cycle was selected as the most suitable for hydrogen combustion turbine used for industrial power plant by the Japanese government. A closed circuit steam cooling system has been proposed to cool vanes and blades of the high temperature turbine (HIT) which has inlet temperature of 1700°C and inlet pressure of 45bar. This paper presents the comparisons of the thermal efficiency and the feasibility of components between the CCCTR cycle and other cycles.

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