The Transpiration-Cooled Gas Turbine

1970 ◽  
Vol 92 (4) ◽  
pp. 351-358 ◽  
Author(s):  
F. J. Bayley ◽  
A. B. Turner
Keyword(s):  
Heat Transfer ◽  
Gas Turbine ◽  
Turbulent Boundary Layers ◽  
Transpiration Cooling ◽  
Combustion System ◽  
Transfer Rates ◽  
Thermodynamic Performance ◽  
Porous Surfaces ◽  
Analytical Research ◽  
High Temperature Gas

This paper describes a program of experimental and analytical research designed to evaluate the aerodynamic and thermodynamic performance of transpiration-cooled porous surfaces in the high-temperature gas turbine. The aerodynamic penalties of effusing coolant through a set of nozzle blades are shown to be small, particularly when compared with the thermodynamic advantages which accrue from the effective cooling obtained. Although the effusing coolant can in certain circumstances increase gas to blade heat transfer rates by destabilizing a laminar boundary layer, in the turbulent boundary layers which predominate in turbine practice there is inevitably a reduction in heat transfer which can be satisfactorily predicted theoretically. In the combustion system of the gas turbine, transpiration cooling appears also to be very attractive, but much work remains to be done on heat transfer rates in the flame-tube.

Conceptual Design and Cooling Blade Development of 1700°C Class High-Temperature Gas Turbine

2005 ◽  
Vol 127 (2) ◽  
pp. 358-368 ◽  
Author(s):  
Shoko Ito ◽  
Hiroshi Saeki ◽  
Asako Inomata ◽  
Fumio Ootomo ◽  
Katsuya Yamashita ◽  
...  
Keyword(s):  
Heat Transfer ◽  
High Temperature ◽  
Gas Turbine ◽  
Conceptual Design ◽  
Thermal Efficiency ◽  
Internal Cooling ◽  
Closed Cycle ◽  
Steam Consumption ◽  
Flow Phenomena ◽  
High Temperature Gas

In this paper we describe the conceptual design and cooling blade development of a 1700°C-class high-temperature gas turbine in the ACRO-GT-2000 (Advanced Carbon Dioxide Recovery System of Closed-Cycle Gas Turbine Aiming 2000 K) project. In the ACRO-GT closed cycle power plant system, the thermal efficiency aimed at is more than 60% of the higher heating value of fuel (HHV). Because of the high thermal efficiency requirement, the 1700°C-class high-temperature gas turbine must be designed with the minimum amount of cooling and seal steam consumption. The hybrid cooling scheme, which is a combination of closed loop internal cooling and film ejection cooling, was chosen from among several cooling schemes. The elemental experiments and numerical studies, such as those on blade surface heat transfer, internal cooling channel heat transfer, and pressure loss and rotor coolant passage distribution flow phenomena, were conducted and the results were applied to the conceptual design advancement. As a result, the cooling steam consumption in the first stage nozzle and blade was reduced by about 40% compared with the previous design that was performed in the WE-NET (World Energy Network) Phase-I.

Transpiration Cooled Turbines

1970 ◽  
Vol 185 (1) ◽  
pp. 943-951 ◽  
Author(s):  
F. J. Bayley ◽  
A. B. Turner
Keyword(s):  
Heat Transfer ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Air Cooling ◽  
Transpiration Cooling

This paper lists the steps in the development chain of air cooling for gas turbine components, and represents transpiration cooling as the ultimate method. The three modes of heat transfer involved in transpiration cooling, gas side heat transfer, coolant side heat transfer and interstitial heat transfer, are discussed separately. Finally, consideration is given to the practical problems of transpiration cooling in advanced gas turbines.

Gas Turbimes for High-Specific-Output Industrial Heat-Transfer Equipment

1972 ◽  
Vol 186 (1) ◽  
pp. 205-220
Author(s):  
E. Kellett
Keyword(s):  
Heat Transfer ◽  
Convective Heat Transfer ◽  
Gas Turbine ◽  
Convective Heat ◽  
Gas Turbines ◽  
Low Cost ◽  
Heat Transfer Fluid ◽  
Transfer Rates ◽  
High Heat Transfer ◽  
Pressurized Combustion

The incompatibility of the dual role of air as a combustion and heat-transfer fluid is apparent in the unbalance of convective heat transfer in a water boiler. Pressurized combustion has, since the middle of the nineteenth century, been postulated as a means of increasing the gas-side convective heat transfer to more nearly correspond with the water-side rate. Gas turbines, in the form of turbine-driven supercharged boilers, have been made, but without significant commercial success, in Europe and America. Modern gas turbines are employed in total-energy systems but because of the premium value of their shaft power output, additional heat exchangers must have the minimum pressure loss and therefore conventional heat-transfer criteria apply. Small turbine-driven superchargers are now mass produced for automotive diesel engines and particularly with the availability of natural gas the feasibility of pressurized combustion by their use justifies re-appraisal. Although these turbochargers have little value as gas-turbine power units the margin of turbine output over compressor power absorption can be employed to improve heat-exchanger convective heat-transfer rates significantly. The provision of a second compressor in the rotor system enables a stoichiometric air and gaseous fuel charge to be induced into a simple pre-mixed combustor thus preserving the low-cost aspect of the turbocharger and providing improved control and safety in a very durable gas-turbine device. The addition of a simple after-burner allows total combustion at relatively low excess air rates. The arguments leading to the foregoing design are presented and some of the more important product developments are described. Examination of the wider application potential of such low-cost turbomachinery indicates prospects for their employment in diverse uses particularly where high heat-transfer rates are desirable.

scholarly journals Numerical Investigation on Radiation Effect in Transpiration Cooling

2021 ◽  
Vol 2097 (1) ◽  
pp. 012011
Author(s):  
Kang Qian ◽  
Taolue Liu ◽  
Fei He ◽  
Meng Wang ◽  
Longsheng Tang ◽  
...  
Keyword(s):  
Heat Transfer ◽  
High Temperature ◽  
Gas Flow ◽  
Radiation Effect ◽  
Porous Wall ◽  
Radiation Absorption ◽  
Transpiration Cooling ◽  
Coupled Modeling ◽  
High Temperature Gas ◽  
Numerical Strategy

Abstract This paper proposed a numerical strategy which could achieve the coupled modeling and solving of transpiration cooling with external high-temperature gas flow and especially take the radiation effect into account. Based on the numerical strategy, the heat and mass transfer characteristics of the transpiration cooling in a high-temperature gas channel were studied, and the radiation effect and corresponding influence factors were analyzed. The results indicated that the radiative heat flux takes an important role in the heat transfer between the transpiration cooling and external high-temperature gas flow which may reach 40% under the operating condition considered in this work, and the radiation absorption from the coolant is more obvious near the downstream wall. As the wall emissivity increases, the radiation heat transfer in the downstream area of the porous wall is enhanced significantly and thereby the wall temperature there increases, as the result, the uniformity of the temperature distribution on the whole porous wall is improved to some extent.

Calculation of the Expansion Through a Cooled Gas Turbine Stage

2005 ◽  
Author(s):  
Leonardo Torbidoni ◽  
J. H. Horlock
Keyword(s):  
Heat Transfer ◽  
Gas Turbine ◽  
Thermodynamic Efficiency ◽  
Work Output ◽  
Turbine Stage ◽  
Mean Flow ◽  
Transfer Processes ◽  
Viscous Losses ◽  
The Mean ◽  
High Temperature Gas

In recent work by the same authors [1], a new method for calculating the coolant flow requirements of a high temperature gas turbine blade was described. It involved consideration of successive chord-wise strips of blading; the coolant required in each strip was obtained by detailed study of the heat transfer processes across the wall of the blade and then setting limits on the maximum blade metal temperature. In the present paper, the gas state paths, involving viscous losses, heat transfer and mixing of the coolant with the mainstream, are determined strip-by-strip along the whole blade chord for the stator and rotor of the stage and illustrated on an enthalpy-entropy chart. The work output from each rotor strip is obtained together with the losses [entropy creation] through the whole stage. It is then possible to calculate the thermodynamic efficiency for the cooled turbine stage and compare it with that of the uncooled stage. Illustrative calculations are given, a main calculation being based on the mean flow across the blade pitch. But, in a second supplementary calculation, allowance is also made for flow variations across the blade pitch. By comparing these two calculations it is shown that the mean flow calculation is usually adequate.

Thermal-Fluid and Mechanical Investigations of Additively Manufactured Geometries for Transpiration Cooling

2019 ◽  
Author(s):  
Zheng Min ◽  
Sarwesh Narayan Parbat ◽  
Li Yang ◽  
Minking K. Chyu
Keyword(s):  
Heat Transfer ◽  
Tensile Strength ◽  
Additive Manufacturing ◽  
Ultimate Tensile Strength ◽  
Mechanical Strength ◽  
Pore Size ◽  
Gas Turbine ◽  
Transpiration Cooling ◽  
Direct Metal Laser Sintering ◽  
Cooling Effectiveness

Abstract Transpiration cooling has always been the dream of gas turbine high temperature component design. The uniform coolant coverage and enhanced heat transfer in porous wall provided by this cooling technique can significantly reduce the base metal temperature which is essential for improving working efficiencies and operation life of gas turbine. Recently, with the capability of the innovative powder bed direct metal laser sintering (DMLS) additive manufacturing technology, the complex geometries of transpiration cooling part could be precisely fabricated and endued with improved mechanical strength. In the present study, five different schemes of transpiration cooling including (1) round holes with 1.5d in-line pitch, (2) round holes with 2d in-line pitch, (3) round holes with 3d in-line pitch, (4) round holes with 2d staggered pitch, (5) inclined holes (20° inclination towards the main stream direction) with 2d in-line pitch in In718 superalloy plates were fabricated by direct metal laser sintering (DMLS) printer. Temperature measurements of the hot side surfaces with coolant coverage were conducted to evaluate the cooling performances of those structures. Tensile bars containing the same designed structure as the heat transfer test coupons in the gauge part were printed as well for the evaluation of the ultimate tensile strength. The test results showed that the coupons with smaller pore size had higher cooling effectiveness but lower tensile strength. The smaller pitch value (P = 1.5D) and the staggered pattern could enhance the cooling performance but decrease the mechanical strength as well. Taking both cooling efficiency and mechanical strength into consideration, the 0.3mm pore size coupon with 3d in-line pitch round holes is considered to be the optimal design with cooling effectiveness of 0.48 at the injection ratio of 2.5% and ultimate tensile strength of 775.9MPa. The present research work demonstrated the potential of additive manufacturing to design and fabricate the transpiration cooling structure with high cooling efficiencies and desired tensile strength.

Concept for a Combustion System in Oxyfuel Gas Turbine Combined Cycles

2013 ◽  
Author(s):  
Sven Gunnar Sundkvist ◽  
Adrian Dahlquist ◽  
Jacek Janczewski ◽  
Mats Sjödin ◽  
Marie Bysveen ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Combined Cycle ◽  
Combustion Stability ◽  
Working Fluid ◽  
Outlet Temperature ◽  
Exhaust Gas ◽  
Combustion System ◽  
Combined Cycles

A promising candidate for CO2 neutral power production is Semi-Closed Oxyfuel Combustion Combined Cycles (SCOC CC). Two alternative SCOC-CCs have been investigated both with recirculation of the Working Fluid (CO2 and H2O) but with different H2O content due to different conditions for condensation of water from the Working Fluid. The alternative with low moisture content in the re-circulated Working Fluid has shown highest thermodynamic potential and has been selected for further study. The necessity to use recirculated exhaust gas as the Working Fluid will make the design of the gas turbine quite different from a conventional gas turbine. For a combined cycle using a steam Rankine cycle as a bottoming cycle it is vital that the temperature of the exhaust gas from the Brayton cycle is well suited for steam generation that fits steam turbine live steam conditions. For oxyfuel gas turbines with a combustor outlet temperature of the same magnitude as conventional gas turbines a much higher pressure ratio is required (close to twice the ratio as for a conventional gas turbine) in order to achieve a turbine outlet temperature suitable for combined cycle. Based on input from the optimized cycle calculations a conceptual combustion system has been developed, where three different combustor feed streams can be controlled independently: the natural gas fuel, the oxidizer consisting mainly of oxygen plus some impurities, and the re-circulated Working Fluid. This gives more flexibility compared to air-based gas turbines, but introduces also some design challenges. A key issue is how to maintain high combustion efficiency over the entire load range using as little oxidizer as possible and with emissions (NOx, CO, UHC) within given constraints. Other important challenges are related to combustion stability, heat transfer and cooling, and material integrity, all of which are much affected when going from air-based to oxygen-based gas turbine combustion. Matching with existing air-based burner and combustor designs has been done in order to use as much as possible of what is proven technology today. The selected stabilization concept, heat transfer evaluation, burner and combustion chamber layout will be described. As a next step the pilot burner will be tested both at atmospheric and high pressure conditions.

Conceptual Design and Cooling Blade Development of 1700 °C-Class High-Temperature Gas Turbine

2003 ◽  
Author(s):  
Shoko Ito ◽  
Hiroshi Saeki ◽  
Asako Inomata ◽  
Fumio Ootomo ◽  
Katsuya Yamashita ◽  
...  
Keyword(s):  
Heat Transfer ◽  
High Temperature ◽  
Gas Turbine ◽  
Conceptual Design ◽  
Thermal Efficiency ◽  
Internal Cooling ◽  
Closed Cycle ◽  
Steam Consumption ◽  
Flow Phenomena ◽  
High Temperature Gas

This paper describes the conceptual design and cooling blade development of a 1700 °C-class high-temperature gas turbine in the ACRO-GT-2000 (Advanced Carbon Dioxide Recovery System of Closed-Cycle Gas Turbine Aiming 2000K) project. In the ACRO-GT closed cycle power plant system, the thermal efficiency aimed at is more than 60% of higher heating value of fuel (HHV). Because of the high thermal efficiency requirement, the 1700 °C-class high-temperature gas turbine must be designed with the minimum amount of cooling and seal steam consumption. The hybrid cooling scheme, which is a combination of closed loop internal cooling and film ejection cooling, was chosen from among several cooling schemes. The elemental experiments and numerical studies, such as those on blade surface heat transfer, internal cooling channel heat transfer and pressure loss and rotor coolant passage distribution flow phenomena, were conducted and the results were applied to the conceptual design advancement. As a result, the cooling steam consumption in the first stage nozzle and blade was reduced by about 40% compared with the previous design that was performed in the WE-NET (World Energy Network) Phase-I.

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