On the Design of High-Temperature Gas Turbine Blade Water-Cooling Channels

1978 ◽  
Vol 100 (4) ◽  
pp. 586-591 ◽  
Author(s):  
M. A. El-Masri ◽  
J. F. Louis
Keyword(s):  
High Temperature ◽  
Gas Turbines ◽  
Critical Thickness ◽  
Ambient Pressure ◽  
Rectangular Channel ◽  
Heat Fluxes ◽  
Strong Impact ◽  
Water Cooling ◽  
Cooling Passage ◽  
High Temperature Gas

Centrifugal and Coriolis accelerations have a strong impact on the fluid dynamics and heat transfer in the various schemes of water cooling being actively considered for rotating blades in very high temperature gas turbines. Analytical studies of a thin water film in a rotating rectangular channel open to ambient pressure are presented. First, the dynamics of a thin rotating film indicate that for a certain flow rate it thins out into a stable film under the action of the Coriolis force only for a flow depth below a critical thickness. The value of the critical thickness is a function of the tilt angle between the axis of the cooling passage and the radial. Criteria for nucleation and burnout in high speed liquid films are proposed. These criteria are used to estimate the coolant requirements for representative heat fluxes at different ambient pressures. They suggest that coolant demand increases drastically with pressure. The maximum coolant demand at a fixed heat flux would occur in the neighborhood of five bars.

An Improved Nickel Based MIMS Thermocouple for High Temperature Gas Turbine Applications

2012 ◽  
Author(s):  
Michele Scervini ◽  
Catherine Rae
Keyword(s):  
High Temperature ◽  
Gas Turbine ◽  
High Temperatures ◽  
Gas Turbines ◽  
Material Science ◽  
University Of Cambridge ◽  
Type K ◽  
Metallurgical Analysis ◽  
The University ◽  
High Temperature Gas

A new Nickel based thermocouple for high temperature applications in gas turbines has been devised at the Department of Material Science and Metallurgy of the University of Cambridge. This paper describes the new features of the thermocouple, the drift tests on the first prototype and compares the behaviour of the new sensor with conventional mineral insulated metal sheathed Type K thermocouples: the new thermocouple has a significant improvement in terms of drift and temperature capabilities. Metallurgical analysis has been undertaken on selected sections of the thermocouples exposed at high temperatures which rationalises the reduced drift of the new sensor. A second prototype will be tested in follow-on research, from which further improvements in drift and temperature capabilities are expected.

scholarly journals FEATURES OF ORGANIZATION OF FILM COOLING OF HIGH TEMPERATURE GAS TURBINES BLADES

2017 ◽  
Vol 39 (4) ◽  
pp. 11-20
Author(s):  
A. A. Khalatov ◽  
A. S. Kovalenko ◽  
S. B. Reznik
Keyword(s):  
High Temperature ◽  
Film Cooling ◽  
Gas Turbines ◽  
Small Dimension ◽  
Cooling Efficiency ◽  
Local Distribution ◽  
Cooling Air ◽  
High Temperature Gas

The features of the release of the cooling air in the interscapular channel high temperature gas turbines at the film cooling are considered. Possibilities of its local distribution on contour of an entrance edge of the perforated blades are investigated. The presented calculations show that the substantial increase in the cooling efficiency can be attained due to channels of small dimension in the blade wall.  

A Catalytic Combustor for High-Temperature Gas Turbines

1996 ◽  
Vol 118 (1) ◽  
pp. 61-64 ◽  
Author(s):  
N. Vortmeyer ◽  
M. Valk ◽  
G. Kappler
Keyword(s):  
High Temperature ◽  
Gas Turbines ◽  
Essential Feature ◽  
Research Work ◽  
Thermal Reactor ◽  
Experimental Investigations ◽  
Phase Reaction ◽  
Catalyst Temperature ◽  
Catalytic Combustor ◽  
High Temperature Gas

Catalytic combustion has been the subject of thorough research work for over two decades, mainly in the U.S. and Japan. However, severe material problems in the ceramic or metallic monolith prevented regular operation in most cases. Still, during these two decades, turbine inlet temperatures were raised remarkably, and lean premix combustors have become standard in stationary gas turbines. In view of these facts, a simple “monolith-in-tube” concept of a catalytic combustor was adapted for the use in high-temperature gas turbines. Its essential feature is the fact that a considerable portion of the homogeneous gas phase reaction is shifted to the thermal reactor, thus lowering the catalyst temperature. This is achieved by the employment of very short catalyst segments. The viability of this concept has been demonstrated for a variety of pure hydrocarbons, alcohols as well as common liquid fuels. Extensive experimental investigations of the atmospheric combustor led to the assessment of parameters such as reference velocity, fuel-to-air ratio, and fuel properties. The maximum combustor exit temperature was 1673 K with a corresponding catalyst temperature of less than 1300 K for diesel fuel. Boundary conditions were in all cases combustion efficiency (over 99.9 percent) and pressure loss (less than 6 percent). Additionally, a model has been developed to predict the characteristic values of the catalytic combustor such as necessary catalyst length, combustor volume, and emission characteristics. The homogeneous reaction in the thermal reactor can be calculated by a one-dimensional reacting flow model.

scholarly journals Gas Turbine Power Plant Possibilities With a Nuclear Heat Source: Closed and Open Cycles

1990 ◽  
Author(s):  
Colin F. McDonald
Keyword(s):  
High Temperature ◽  
Power Plant ◽  
Heat Source ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Combined Cycle ◽  
Closed Cycle ◽  
Cycle System ◽  
Nuclear Heat ◽  
High Temperature Gas

With the capability of burning a variety of fossil fuels, giving high thermal efficiency, and operating with low emissions, the gas turbine is becoming a major prime-mover for a wide spectrum of applications. Almost three decades ago two experimental projects were undertaken in which gas turbines were actually operated with heat from nuclear reactors. In retrospect, these systems were ahead of their time in terms of technology readiness, and prospects of the practical coupling of a gas turbine with a nuclear heat source towards the realization of a high efficiency, pollutant free, dry-cooled power plant has remained a long-term goal, which has been periodically studied in the last twenty years. Technology advancements in both high temperature gas-cooled reactors, and gas turbines now make the concept of a nuclear gas turbine plant realizable. Two possible plant concepts are highlighted in this paper, (1) a direct cycle system involving the integration of a closed-cycle helium gas turbine with a modular high temperature gas cooled reactor (MHTGR), and (2) the utilization of a conventional and proven combined cycle gas turbine, again with the MHTGR, but now involving the use of secondary (helium) and tertiary (air) loops. The open cycle system is more equipment intensive and places demanding requirements on the very high temperature heat exchangers, but has the merit of being able to utilize a conventional combined cycle turbo-generator set. In this paper both power plant concepts are put into perspective in terms of categorizing the most suitable applications, highlighting their major features and characteristics, and identifying the technology requirements. The author would like to dedicate this paper to the late Professor Karl Bammert who actively supported deployment of the closed-cycle gas turbine for several decades with a variety of heat sources including fossil, solar, and nuclear systems.

scholarly journals A Catalytic Combustor for High-Temperature Gas Turbines

1994 ◽  
Author(s):  
Nicolas Vortmeyer ◽  
Martin Valk ◽  
Günter Kappler
Keyword(s):  
High Temperature ◽  
Gas Turbines ◽  
Essential Feature ◽  
Research Work ◽  
Thermal Reactor ◽  
Experimental Investigations ◽  
Phase Reaction ◽  
Catalyst Temperature ◽  
Catalytic Combustor ◽  
High Temperature Gas

Catalytic combustion has been the subject of thorough research work for over two decades, mainly in the U.S. and Japan. However, severe material problems in the ceramic or metallic monolith prevented regular operation in most cases. Still, during these two decades, turbine inlet temperatures were raised remarkably, and lean premix combustors have become standard in stationary gas turbines. In view of these facts, a simple “monolith-in-tube” concept of a catalytic combustor was adapted for the use in high-temperature gas turbines. Its essential feature is the fact that a considerable portion of the homogeneous gas phase reaction is shifted to the thermal reactor, thus lowering the catalyst temperature. This is achieved by the employment of very short catalyst segments. The viability of this concept has been demonstrated for a variety of pure hydrocarbons, alcohols as well as common liquid fuels. Extensive experimental investigations of the atmospheric combustor lead to the assessment of parameters such as reference velocity, fuel-to-air ratio and fuel properties. The maximum combustor exit temperature was 1,673 K with a corresponding catalyst temperature of less than 1,300 K for Diesel fuel. Boundary conditions were in all cases combustion efficiency (over 99.9%) and pressure loss (less than 6%). Additionally, a model has been developped to predict the characteristic values of the catalytic combustor such as necessary catalyst length, combustor volume and emission characteristics. The homogeneous reaction in the thermal reactor can be calculated by a one-dimensional reacting flow model.

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