Thermal performance prediction of a solar hybrid gas turbine

This paper is Part I of a study concerned with developing a formal framework for modelling air-cooled gas turbine cycles and deals with basic thermodynamic issues. Such cycles involve gas mixtures with varying composition which must be modelled realistically. A possible approach is to define just two components, air and gas, the latter being the products of stoichiometric combustion of the fuel with air. If these components can be represented as ideal gases, the entropy increase due to compositional mixing, although a true exergy loss, can be ignored for the purpose of performance prediction. This provides considerable simplification. Consideration of three idealised simple cycles shows that the introduction of cooling with an associated thermal mixing loss does not necessarily result in a loss of cycle efficiency. This is no longer true when real gas properties and turbomachinery losses are included. The analysis clarifies the role of the cooling losses and shows the importance of assessing performance in the context of the complete cycle. There is a strong case for representing the cooling losses in terms of irreversible entropy production as this provides a formalised framework, clarifies the modelling difficulties and aids physical interpretation. Results are presented which show the effects on performance of varying cooling flowrates and cooling losses. A comparison between simple and reheat cycles highlights the rôle of the thermal mixing loss. Detailed modelling of the heat transfer and cooling losses is discussed in Part II of this paper.

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Experimental Study on Flow Behavior and Heat Transfer Enhancement with Distinct Dimpled Gas Turbine Blade Internal Cooling Channel

Journal of Energy Resources Technology ◽

10.1115/1.4052035 ◽

2021 ◽

pp. 1-28

Author(s):

Farah Nazifa Nourin ◽

Ryoichi S. Amano

Keyword(s):

Heat Transfer ◽

Pressure Drop ◽

Heat Transfer Enhancement ◽

Gas Turbine ◽

Turbine Blade ◽

Thermal Performance ◽

Diameter Ratio ◽

Internal Cooling ◽

Cooling Channel ◽

Transfer Enhancement

Abstract The study presents the investigation on heat transfer distribution along a gas turbine blade internal cooling channel. Six different cases were considered in this study, using the smooth surface channel as a baseline. Three different dimples depth-to-diameter ratios with 0.1, 0.25, and 0.50 were considered. Different combinations of partial spherical and leaf dimples were also studied with the Reynolds numbers of 6,000, 20,000, 30,000, 40,000, and 50,000. In addition to the experimental investigation, the numerical study was conducted using Large Eddy Simulation (LES) to validate the data. It was found that the highest depth-to-diameter ratio showed the highest heat transfer rate. However, there is a penalty for increased pressure drop. The highest pressure drop affects the overall thermal performance of the cooling channel. The results showed that the leaf dimpled surface is the best cooling channel based on the highest Reynolds number's heat transfer enhancement and friction factor. However, at the lowest Reynolds number, partial spherical dimples with a 0.25 depth to diameter ratio showed the highest thermal performance.

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Performance Improvement Program for Kawasaki Gas Turbine

Volume 3: Coal, Biomass and Alternative Fuels; Cycle Innovations; Electric Power; Industrial and Cogeneration Applications; Organic Rankine Cycle Power Systems ◽

10.1115/gt2017-63333 ◽

2017 ◽

Author(s):

Tomoki Taniguchi ◽

Ryoji Tamai ◽

Yoshihiko Muto ◽

Satoshi Takami ◽

Ryozo Tanaka ◽

...

Keyword(s):

Gas Turbine ◽

Thermal Performance ◽

Film Cooling ◽

Gas Turbines ◽

Large Scale ◽

New Technologies ◽

Design Procedure ◽

Product Line ◽

Combined Cycle ◽

Improvement Program

Kawasaki Heavy Industries, Ltd (KHI) has started a comprehensive program to further improve performance and availability of existing Kawasaki gas turbines. In the program, one of the Kawasaki’s existing gas turbine was selected from the broad product line and various kinds of technology were investigated and adopted to further improve its thermal performance and availability. The new technologies involve novel film cooling of turbine nozzles, advanced and large-scale numerical simulations, new thermal barrier coating. The thermal performance target is combined cycle efficiency of 51.6% and the target ramp rate is 20% load per minute. The program started in 2015 and engine testing has just started. In this paper, details of the program are described, focusing on design procedure.

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