Waste Energy Utilization in Regenerative Gas Turbine Cycles

1986 ◽  
Author(s):  
Yousef S. H. Najjar ◽  
Taha K. Aldoss
Keyword(s):  
Heat Exchanger ◽  
Gas Turbine ◽  
Power Output ◽  
Energy Utilization ◽  
Inlet Pressure ◽  
Maximum Temperature ◽  
Regenerative Heat ◽  
Turbine Engine ◽  
Turbine Inlet ◽  
Delivery Pressure

One of the ways that can be used to increase the efficiency of a shaft gas turbine engine is by installing a regenerative heat exchanger in one of the following two configurations: 1. after the low pressure turbine (usual case). 2. after the high pressure turbine (suggested). Analysis of ideal cycles as well as real cycle for both configurations is done by using a computer program, where the following parameters were studied: heat exchanger effectiveness, turbine efficiency, compressor efficiency, ratio of turbine inlet pressure to compressor delivery pressure (P3/P2), and maximum temperature ratio (T3/T1). From the sensitivity analysis for both configurations the usual configuration is inferior to the suggested in terms of the relative effects of compressor and turbine efficiencies on the overall efficiency and turbine inlet pressure on overall thermal efficiency and power output. However, the usual method is superior with respect to the relative effects of the compressor and turbine efficiencies on power output and flow path design and manufacture.

scholarly journals The effect of heat recovery on the optimal values of helicopter turboshaft engine parameters

2020 ◽  
Vol 19 (4) ◽  
pp. 43-57
Author(s):  
H. H. Omar ◽  
V. S. Kuz'michev ◽  
A. O. Zagrebelnyi ◽  
V. A. Grigoriev
Keyword(s):  
Heat Exchanger ◽  
Gas Turbine ◽  
Heat Recovery ◽  
Thermodynamic Cycle ◽  
Gas Turbine Engine ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Working Process ◽  
Turbine Engine ◽  
Recuperative Heat Exchanger

Recent studies related to fuel economy in air transport conducted in our country and abroad show that the use of recuperative heat exchangers in aviation gas turbine engines can significantly, by up to 20...30%, reduce fuel consumption. Until recently, the use of cycles with heat recovery in aircraft gas turbine engines was restrained by a significant increase in the mass of the power plant due to the installation of a heat exchanger. Currently, there is a technological opportunity to create compact, light, high-efficiency heat exchangers for use on aircraft without compromising their performance. An important target in the design of engines with heat recovery is to select the parameters of the working process that provide maximum efficiency of the aircraft system. The article focused on setting of the optimization problem and the choice of rational parameters of the thermodynamic cycle parameters of a gas turbine engine with a recuperative heat exchanger. On the basis of the developed method of multi-criteria optimization the optimization of thermodynamic cycle parameters of a helicopter gas turbine engine with a ANSAT recuperative heat exchanger was carried out by means of numerical simulations according to such criteria as the total weight of the engine and fuel required for the flight, the specific fuel consumption of the aircraft for a ton- kilometer of the payload. The results of the optimization are presented in the article. The calculation of engine efficiency indicators was carried out on the basis of modeling the flight cycle of the helicopter, taking into account its aerodynamic characteristics. The developed mathematical model for calculating the mass of a compact heat exchanger, designed to solve optimization problems at the stage of conceptual design of the engine and simulation of the transport helicopter flight cycle is presented. The developed methods and models are implemented in the ASTRA program. It is shown that optimal parameters of the working process of a gas turbine engine with a free turbine and a recuperative heat exchanger depend significantly on the heat exchanger effectiveness. The possibility of increasing the efficiency of the engine due to heat regeneration is also shown.

scholarly journals Thermodynamic modelling and efficiency analysis of a class of real indirectly fired gas turbine cycles

2009 ◽  
Vol 13 (4) ◽  
pp. 41-48
Author(s):  
Zheshu Ma ◽  
Zhenhuan Zhu
Keyword(s):  
High Temperature ◽  
Heat Exchanger ◽  
Gas Turbine ◽  
Power Output ◽  
Gas Turbines ◽  
Waste Heat ◽  
Operational Parameters ◽  
Forecast Performance ◽  
Micro Gas Turbine ◽  
Temperature Heat

Indirectly or externally-fired gas-turbines (IFGT or EFGT) are novel technology under development for small and medium scale combined power and heat supplies in combination with micro gas turbine technologies mainly for the utilization of the waste heat from the turbine in a recuperative process and the possibility of burning biomass or 'dirty' fuel by employing a high temperature heat exchanger to avoid the combustion gases passing through the turbine. In this paper, by assuming that all fluid friction losses in the compressor and turbine are quantified by a corresponding isentropic efficiency and all global irreversibilities in the high temperature heat exchanger are taken into account by an effective efficiency, a one dimensional model including power output and cycle efficiency formulation is derived for a class of real IFGT cycles. To illustrate and analyze the effect of operational parameters on IFGT efficiency, detailed numerical analysis and figures are produced. The results summarized by figures show that IFGT cycles are most efficient under low compression ratio ranges (3.0-6.0) and fit for low power output circumstances integrating with micro gas turbine technology. The model derived can be used to analyze and forecast performance of real IFGT configurations.

Performance Improvement of Gas Turbine Power Plant by Intake Air Passive Cooling Using Phase Change Material Based Heat Exchanger

2017 ◽  
Author(s):  
Devendra Dandotiya ◽  
Nitin D. Banker
Keyword(s):  
Heat Exchanger ◽  
Ambient Temperature ◽  
Phase Change ◽  
Gas Turbine ◽  
Air Temperature ◽  
Power Output ◽  
Ambient Air ◽  
Passive Cooling ◽  
Air Intake ◽  
Change Material

The power output of a gas turbine plant decreases with the increase in ambient temperature. Moreover, the ambient temperature fluctuates about 15–20°C in a day. Hence, cooling of intake air makes a noticeable improvement to the gas turbine performance. In this regard, various active cooling techniques such as vapor compression refrigeration, vapor absorption refrigeration, vapor adsorption refrigeration and evaporative cooling are applied for the cooling of intake air. This paper presents a new passive cooling technique where the intake air temperature is reduced by incorporating phase change material (PCM) based heat exchanger parallel to conventional air intake line. During the daytime, the air is passed through the PCM which has melting temperature lower than the peak ambient temperature. This will reduce the ambient air temperature before taking to the compressor. Once the PCM melts completely, the required ambient air would be drawn from the ambient through conventional air intake arrangement. During the night, when there is lower ambient temperature, PCM converts from liquid to solid. The selected PCM has a melting temperature less than the peak ambient temperature and higher than the minimum ambient temperature. It is observed from the numerical modeling of the PCM that about four hours are required for the melting of PCM and within this time, the intake air can also be cooled by 5°C. The thermodynamic analysis of the results showed about 5.2% and 5.2% improvement in net power output and thermal efficiency, respectively for four hours at an ambient temperature of 45°C.

Feasibility Study of a Radical Vane-Integrated Heat Exchanger for Turbofan Engine Applications

2020 ◽  
Author(s):  
Isak Jonsson ◽  
Carlos Xisto ◽  
Hamidreza Abedi ◽  
Tomas Grönstedt ◽  
Marcus Lejon
Keyword(s):  
Heat Exchanger ◽  
Gas Turbine ◽  
Conceptual Design ◽  
Feasibility Study ◽  
Compact Heat Exchanger ◽  
Turbofan Engine ◽  
Turbine Engine ◽  
Compression System ◽  
Last Stage ◽  
Pressure Compressor

Abstract In the present study, a compact heat exchanger for cryogenically fueled gas turbine engine applications is introduced. The proposed concept can be integrated into one or various vanes that comprise the compression system and uses the existing vane surface to reject core heat to the cryogenic fuel. The requirements for the heat exchanger are defined for a large geared-turbofan engine operating on liquid hydrogen. The resulting preliminary conceptual design is integrated into a modified interconnecting duct and connected to the last stage of a publicly available low-pressure compressor geometry. The feasibility of different designs is investigated numerically, providing a first insight on the parameters that govern the design of such a component.

Analysis of Heat Exchanger Concepts for Use As Gas Turbine Intercoolers

2001 ◽  
Author(s):  
Arash Saidi ◽  
Daniel Eriksson ◽  
Bengt Sundén
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Pressure Drop ◽  
Gas Turbine ◽  
Power Output ◽  
Heat Exchangers ◽  
Advantages And Disadvantages ◽  
Volume Weight ◽  
Different Types ◽  
Core Volume

Abstract This paper presents a discussion and comparison of some heat exchanger types readily applicable to use as intercoolers in gas turbine systems. The present study concerns a heat duty of the intercooler for a gas turbine of around 17 MW power output. Four different types of air-water heat exchangers are considered. This selection is motivated because of the practical aspects of the problem. Each configuration is discussed and explained, regarding advantages and disadvantages. The available literature on the pressure drop and heat transfer correlations is used to determine the thermal-hydraulic performance of the various heat exchangers. Then a comparison of the intercooler core volume, weight, pressure drop is presented.

The Heat Transfer Performance of Porous Gas Turbine Blades

1968 ◽  
Vol 72 (696) ◽  
pp. 1087-1094 ◽  
Author(s):  
F. J. Bayley ◽  
A. B. Turner
Keyword(s):  
Gas Turbine ◽  
Turbine Blades ◽  
Engine Performance ◽  
Operating Conditions ◽  
Maximum Temperature ◽  
Specific Power ◽  
Working Fluid ◽  
Inlet Temperature ◽  
Turbine Inlet ◽  
Compression And Expansion

It is well known that the performance of the practical gas turbine cycle, in which compression and expansion are non-isentropic, is critically dependent upon the maximum temperature of the working fluid. In engines in which shaft-power is produced the thermal efficiency and the specific power output rise steadily as the turbine inlet temperature is increased. In jet engines, in which the gas turbine has so far found its greatest success, similar advantages of high temperature operation accrue, more particularly as aircraft speeds increase to utilise the higher resultant jet velocities. Even in high by-pass ratio engines, designed specifically to reduce jet efflux velocities for application to lower speed aircraft, overall engine performance responds very favourably to increased turbine inlet temperatures, in which, moreover, these more severe operating conditions apply continuously during flight, and not only at maximum power as with more conventional cycles.

Design, Analysis, and Manufacture of an Axial Length-Saving Disk-Oriented Engine

2020 ◽  
Vol 143 (1) ◽  
Author(s):  
Bennett M. Staton ◽  
Brian T. Bohan ◽  
Marc D. Polanka ◽  
Larry P. Goss
Keyword(s):  
Gas Turbine ◽  
Axial Length ◽  
Electric Propulsion ◽  
Guide Vane ◽  
Combustion Process ◽  
Gas Turbine Engine ◽  
Inlet Temperature ◽  
Turbine Engine ◽  
Power Extraction ◽  
Turbine Inlet

Abstract A disk-oriented engine was designed to reduce the overall length of a gas turbine engine, combining a single-stage centrifugal compressor and radial in-flow turbine (RIT) in a back-to-back configuration. The focus of this research was to understand how this unique flow path impacted the combustion process. Computational analysis was accomplished to determine the feasibility of reducing the axial length of a gas turbine engine utilizing circumferential combustion. The desire was to maintain circumferential swirl from the compressor through a U-bend combustion path. The U-bend reverses the outboard flow from the compressor into an integrated turbine guide vane in preparation for power extraction by the RIT. The computational targets for this design were a turbine inlet temperature of 1300 K, operating with a 3% total pressure drop across the combustor, and a turbine inlet pattern factor (PF) of 0.24 to produce a cycle capable of creating 668 N of thrust. By wrapping the combustion chamber about the circumference of the turbomachinery, the axial length of the entire engine was reduced. Reallocating the combustor volume from the axial to radial orientation reduced the overall length of the system up to 40%, improving the mobility and modularity of gas turbine power in specific applications. This reduction in axial length could be applied to electric power generation for both ground power and airborne distributive electric propulsion. Computational results were further compared to experimental velocity measurements on custom fuel–air swirl injectors at mass flow conditions representative of 668 N of thrust, providing qualitative and quantitative insight into the stability of the flame anchoring system. From this design, a full-scale physical model of the disk-oriented engine was designed for combustion analysis.

Regenerator Development for the British Leyland 2S/350/R Gas Turbine Engine

1974 ◽  
Author(s):  
J. A. Ritchie ◽  
P. A. Phillips ◽  
M. C. S. Barnard
Keyword(s):  
Heat Exchanger ◽  
Gas Turbine ◽  
Gas Turbine Engine ◽  
Turbine Engine ◽  
Single Disk

This paper describes the application of the ceramic regenerator to the British Leyland truck gas turbine. Aspects of mounting, driving and sealing the heat exchanger disk are covered with particular reference to the single disk version of the 2S/350/R engine.

Low-Leakage Modular Regenerators for Gas-Turbine Engines

1997 ◽  
Author(s):  
James Anthony Kluka ◽  
David Gordon Wilson
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Regenerative Heat ◽  
Turbine Engine ◽  
Low Leakage ◽  
The Matrix ◽  
Potential Applications ◽  
Ceramic Honeycomb

One of the significant problems plaguing regenerator designs is seal leakage resulting in a reduction of thermal efficiency. This paper describes the preliminary design and analysis of a new regenerative heat-exchanger concept, called a modular regenerator, that promises to provide improved seal-leakage performance. The modular regenerator concept consists of a ceramic-honeycomb matrix discretized into rectangular blocks, called modules. Separating the matrix into modules substantially reduces the transverse sealing lengths and substantially increases the longitudinal sealing lengths as compared with typical rotary designs. Potential applications can range from small gas-turbine engines for automotive applications to large stationary gas turbines for industrial power generation. Descriptions of two types of modular regenerators are presented including sealing concepts. Results of seal leakage analysis for typical modular regenerators sized for a small gas-turbine engine (120 kW) predict leakage rates under one percent for most seal-clearance heights.

Fabrication and Performance of a Pin Fin Micro Heat Exchanger

2004 ◽  
Vol 126 (3) ◽  
pp. 434-444 ◽  
Author(s):  
Christophe Marques ◽  
Kevin W. Kelly
Keyword(s):  
Heat Exchanger ◽  
Gas Turbine ◽  
Heat Exchangers ◽  
Turbine Blades ◽  
High Heat ◽  
Gas Turbine Engine ◽  
High Heat Flux ◽  
Turbine Engine ◽  
Pin Fin ◽  
Micro Heat Exchanger

Nickel micro pin fin heat exchangers can be electroplated directly onto planar or non-planar metal surfaces using a derivative of the LIGA micromachining process. These heat exchangers offer the potential to more effectively control the temperature of surfaces in high heat flux applications. Of particular interest is the temperature control of gas turbine engine components. The components in the gas turbine engine that require efficient, improved cooling schemes include the gas turbine blades, the stator vanes, the turbine disk, and the combustor liner. Efficient heating of component surfaces may also be required (i.e., surfaces near the compressor inlet to prevent deicing). In all cases, correlations providing the Nusselt number and the friction factor are needed for such micro pin fin heat exchangers. Heat transfer and pressure loss experimental results are reported for a flat parallel plate pin fin micro heat exchanger with a staggered pin fin array, with height-to-diameter ratios of 1.0, with spacing-to-diameter ratios of 2.5 and for Reynolds numbers (based on the hydraulic diameter of the channel) from 4000 to 20,000. The results are compared to studies of larger scale, but geometrically similar, pin fin heat exchangers. To motivate further research, an analytic model is described which uses the empirical results from the pin fin heat exchanger experiments to predict a cooling effectiveness exceeding 0.82 in a gas turbine blade cooling application. As a final point, the feasibility of fabricating a relatively complex micro heat exchanger on a simple airfoil (a cylinder) is demonstrated.

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