Sunao Aoki

Film cooling on a gas turbine rotor blade

The film cooling effectiveness on a low-speed stationary cascade and the rotating blade has been measured by using a heat-mass transfer analogy. The film cooling effectiveness on the suction surface of the rotating blade fits well with that on the stationary blade, but a low level of effectiveness appears on the pressure surface of the rotating blade. In this paper, typical film cooling data will be presented and film cooling on a rotating blade is discussed

Contribution of Heat Transfer to Turbine Blades and Vanes for High Temperature Industrial Gas Turbines Part 1: Film Cooling

Abstract: This paper deals with the contribution of heat transfer to increase the turbine inlet temperature of industrial gas turbines in order to attain efficient and environmentally benign engines. High efficiency film cooling, in the form of shaped film cooling and full coverage film cooling, is one of the most important cooling technologies. Corresponding heat transfer tests to optimize the film cooling effectiveness are shown and discussed in this first part of the contribution.

A Study of Hydrogen Combustion Turbines

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.Copyright

Advanced Turbine Aerodynamic Design Utilizing a Full Stage CFD

Gas turbines for power generation are required to operate more efficiently than ever before for both economic and environmental reasons. Because of this situation, an advanced multistage turbine design and optimization system is required to improve upon existing turbine designs where viscous CFD codes had already been applied on a single row or single stages basis. An advanced CFD code for multistage design applications has been developed at Mitsubishi Heavy Industries (MHI) and has been applied to the redesign of a four stage single shaft turbine. The front 3 stages of the turbine are highly cooled using about 20% cooling air. The outstanding performance of this redesigned turbine has been demonstrated at MHI’s engine test facility. This paper focuses on the customization of the Denton code [5] for industrial usage, the validation of the customized code employing experimental data, and finally the use of the code in executing a successful redesign. Code development and validation are discussed in terms of prediction accuracy for the basic aerodynamic design parameters such as exit flow angle and cascade losses. Through-flow design parameters such as pressure ratio and reaction of each stage are also addressed. Especially important in modern high temperature turbines is the location and distribution of cooling and leakage air being introduced into the main gas-path. The proper treatment of these flows is very important because of the mixing losses and the temperature migration downstream. These important considerations in any analysis approach are discussed and it is shown how they are treated in the customized CFD code. Consistency between the customized CFD code and other parts of the existing aerodynamic design procedure are carefully examined. This is important because aerodynamic parameters have different modeling fidelities in the different parts of the design system. Computer execution times are a very important consideration when utilizing advanced CFD codes. This issue is addressed from the perspective of an industrial design organization. In validating the customized code, special attention was placed on tip clearance leakage flow behavior and seal air migration from the hub wall. Local changes of total pressure and temperature distributions affect the local velocity triangles and local static pressure distributions on the airfoil and end-wall surfaces. Airfoil section geometry and three-dimensional stacking to maximize the turbine efficiency are also considered and discussed. The validated code was subsequently used to execute a redesign of a large frame industrial turbine. This is discussed in some detail. The redesigned turbine has completed full scale engine testing and has been shown to have met all design goals. The CFD predictions are compared with special measurements taken in the engine such as the inter-stage span-wise total pressure and temperature distributions as well as the efficiency trend versus engine load. These comparisons prove the capability of the advanced multistage CFD code.Copyright

Film Cooling on a Gas Turbine Rotor Blade

The film cooling effectiveness on a low-speed stationary cascade and the rotating blade has been measured by using a heat-mass transfer analogy. The film cooling effectiveness on the suction surface of the rotating blade fits well with that on the stationary blade, but a low level of effectiveness appears on the pressure surface of the rotating blade. In this paper, typical film cooling data will be presented and film cooling on a rotating blade is discussed.Copyright

Development and Testing of the 13MW Class Heavy Duty Gas Turbine MF-111

A new 13 MW class heavy duty gas turbine “MF-111” with the combustor outlet temperature of 1250°C (1523 K) was developed and tested.The thermal efficiency of MF-111 is designed to be 32% for simple-cycle and 45% in combined-cycle operation.MF-111 has single-shaft configuration, 15-stage axial flow compressor, 8 cannular type combustors and 3-stage axial flow turbine.Advanced cooling technology was incorporated for the turbine and the combustor design to be capable of higher combustor outlet temperature.The prototype was shoptested at full load in April, 1986. The performance and the metal temperatures of hot parts were confirmed to well satisfy the design goal. The first machine of MF-111 started the commercial operation from August, 1986 and has logged satisfactory operations.© 1987 ASME

Contribution of Heat Transfer to Turbine Blades and Vanes for High Temperature Industrial Gas Turbines Part 2: Heat Transfer on Serpentine Flow Passage

Abstract: The improvement of the heat transfer coefficient of the 1st row blades in high temperature industrial gas turbines is one of the most important issues to ensure reliable performance of these components and to attain high thermal efficiency of the facility. This paper deals with the contribution of heat transfer to increase the turbine inlet temperature of such gas turbines in order to attain efficient and environmentally benign engines. Following the experiments described in Part 1, a set of trials was conducted to clarify the influence of the blades rotating motion on the heat transfer coefficient for internal serpentine flow passages with turbulence promoters. Test results are shown and discussed in this second part of the contribution.

Development of the Next Generation 1500°C Class Advanced Gas Turbine for 50Hz Utilities

The 701G1 50Hz Combustion Turbine continues a long line of large heavy-duty single-shaft combustion turbines by combining the proven efficient and reliable concepts of the 501F and 701F. The output of the 701G1 is 255MW with combined cycle net efficiency of over 57%. A pan of component development was conducted under the joint development program with Tohoku Electric Power Co., Inc. and a part of the design work was carried out under the cooperation with Westinghouse Electric Corporation in the U.S.A. and Fiat Avio in Italy.This gas turbine is going to be installed to “Higashi Niigata Power Plants NO.4” of Tohoku Electric Power Co., Inc. in Japan. This plant will begin commercial operation in 1999.This paper describes some design results and new technologies in designing and developing this next generation 1500°C class advanced gas turbine.Copyright

Uprated 501F Gas Turbine, 501FA

This paper introduces the engineering approach taken in developing the 501FA gas turbine, which is an uprated version of the existing 501F 150MW class gas turbine. The concepts and procedures which were utilized to uprate this gas turbine are also presented. To achieve better performance, new techniques were incorporated which reflected test results and operating experience. No advanced technologies were introduced. Instead, well experienced techniques are adopted so as not to deteriorate reliability. Improvement of the performance was mainly achieved mainly due to the reduction of cooling air. Tip clearances were also optimized based on shop test and field results.Copyright

Development of 6MW-Class Gas Turbine MF-61

The MF-61 is a 6MW-class heavy duty gas turbine which was developed for cogeneration application. A single can type combustor with wide fuel flexibility and advanced high efficiency compressor has been adopted for this engine. The combustor outlet temperature is designed at 1150°C. This paper describes the design concepts of the machine, the design features, and the verification programs carried out in Takasago, Japan. The results of the full load shop test verified that the performance, the mechanical characteristic and the emission well satisfied the initial design goals.Copyright