scholarly journals Advanced Core Technology: Key to Subsonic Propulsion Benefits

1989 ◽  
Author(s):  
Arthur J. Glassman ◽  
Christopher A. Snyder ◽  
Gerald Knip
Keyword(s):  
Thermal Efficiency ◽  
Pressure Ratio ◽  
Constant Current ◽  
Specific Power ◽  
Inlet Temperature ◽  
Turbofan Engines ◽  
Turbine Cooling ◽  
Core Technology ◽  
Specific Power Output ◽  
The Individual

A study was conducted to identify the potential performance benefits and key technology drivers associated with advanced cores for subsonic high-bypass turbofan engines. Investigated first were the individual sensitivities of varying compressor efficiency, pressure ratio and bleed (for turbine cooling); combustor pressure recovery; and turbine efficiency and inlet temperature on thermal efficiency and core specific power output. Then, engine cycle and mission performance benefits were determined for systems incorporating all potentially achievable technology advancements. The individual thermodynamic sensitivities are shown over a range of turbine temperatures (at cruise) from 2900 to 3500 °R and for both constant (current technology) and optimum (maximum thermal efficiency) overall pressure ratios. It is seen that no single parameter by itself will provide a large increase in core thermal efficiency, which is the thermodynamic parameter of most concern for transport propulsion. However, when all potentially achievable advancements are considered, there occurs a synergism that produces significant cycle and mission performance benefits. The nature of these benefits are presented and the technology challenges associated with achieving them are discussed.

scholarly journals Development of a Flexible Turbine Cooling Prediction Tool for Preliminary Design of Gas Turbines

2018 ◽  
Vol 140 (9) ◽  
Author(s):  
Feijia Yin ◽  
Floris S. Tiemstra ◽  
Arvind G. Rao
Keyword(s):  
Gas Turbines ◽  
Pressure Ratio ◽  
Engine Performance ◽  
Thermodynamic Cycle ◽  
Specific Power ◽  
Inlet Temperature ◽  
Turbine Cooling ◽  
Engine Efficiency ◽  
Semi Empirical ◽  
Cooling Air

As the overall pressure ratio (OPR) and turbine inlet temperature (TIT) of modern gas turbines are constantly being increased in the pursuit of increasing efficiency and specific power, the effect of bleed cooling air on the engine performance is increasingly becoming important. During the thermodynamic cycle analysis and optimization phase, the cooling bleed air requirement is either neglected or is modeled by simplified correlations, which can lead to erroneous results. In this current research, a physics-based turbine cooling prediction model, based on semi-empirical correlations for heat transfer and pressure drop, is developed and verified with turbine cooling data available in the open literature. Based on the validated model, a parametric analysis is performed to understand the variation of turbine cooling requirement with variation in TIT and OPR of future advanced engine cycles. It is found that the existing method of calculating turbine cooling air mass flow with simplified correlation underpredicts the amount of turbine cooling air for higher OPR and TIT, thus overpredicting the estimated engine efficiency.

Performance Comparison and Parametric Analysis of sCO2 Power Cycles Configurations

2018 ◽  
Author(s):  
Ali S. Alsagri ◽  
Andrew Chiasson ◽  
Ahmad Aljabr
Keyword(s):  
Power Output ◽  
Thermal Efficiency ◽  
Performance Comparison ◽  
Specific Power ◽  
Brayton Cycle ◽  
Computationally Efficient ◽  
Power Cycles ◽  
Optimization Study ◽  
Specific Power Output ◽  
Improve Calculation

A thermodynamic analysis and optimization of four supercritical CO2 Brayton cycles were conducted in this study in order to improve calculation accuracy; the feasibility of the cycles; and compare the cycles’ design points. In particular, the overall thermal efficiency and the power output are the main targets in the optimization study. With respect to improving the accuracy of the analytical model, a computationally efficient technique using constant conductance (UA) to represent heat exchanger performances is executed. Four Brayton cycles involved in this compression analysis, simple recaptured, recompression, pre-compression, and split expansion. The four cycle configurations were thermodynamically modeled and optimized based on a genetic algorithm (GA) using an Engineering Equation Solver (EES) software. Results show that at any operating condition under 600 °C inlet turbine temperature, the recompression sCO2 Brayton cycle achieves the highest thermal efficiency. Also, the findings show that the simple recuperated cycle has the highest specific power output in spite of its simplicity.

Impact of Inlet Fogging on the Performance of Steam Injected Cooled Gas Turbine Based Combined Cycle Power Plant

2017 ◽  
Author(s):  
Anoop Kumar Shukla ◽  
Onkar Singh
Keyword(s):  
Power Plant ◽  
Gas Turbine ◽  
Film Cooling ◽  
Pressure Ratio ◽  
Steam Injection ◽  
Combined Cycle ◽  
Specific Power ◽  
Temperature Cycle ◽  
Inlet Temperature ◽  
Combined Cycle Power Plant

Gas/steam combined cycle power plants are extensively used for power generation across the world. Today’s power plant operators are persistently requesting enhancement in performance. As a result, the rigour of thermodynamic design and optimization has grown tremendously. To enhance the gas turbine thermal efficiency and specific power output, the research and development work has centered on improving firing temperature, cycle pressure ratio, adopting improved component design, cooling and combustion technologies, and advanced materials and employing integrated system (e.g. combined cycles, intercooling, recuperation, reheat, chemical recuperation). In this paper a study is conducted for combining three systems namely inlet fogging, steam injection in combustor, and film cooling of gas turbine blade for performance enhancement of gas/steam combined cycle power plant. The evaluation of the integrated effect of inlet fogging, steam injection and film cooling on the gas turbine cycle performance is undertaken here. Study involves thermodynamic modeling of gas/steam combined cycle system based on the first law of thermodynamics. The results obtained based on modeling have been presented and analyzed through graphical depiction of variations in efficiency, specific work output, cycle pressure ratio, inlet air temperature & density variation, turbine inlet temperature, specific fuel consumption etc.

Proposal of Innovative Gas Turbine Combined Cycle Power Generation System

2004 ◽  
Author(s):  
Hideto Moritsuka
Keyword(s):  
Power Generation ◽  
Gas Turbine ◽  
Thermal Efficiency ◽  
Pressure Ratio ◽  
Combined Cycle ◽  
Inlet Temperature ◽  
Generation System ◽  
Turbine Inlet Temperature ◽  
Turbine Inlet ◽  
Power Generation System

In order to estimate the possibility to improve thermal efficiency of power generation use gas turbine combined cycle power generation system, benefits of employing the advanced gas turbine technologies proposed here have been made clear based on the recently developed 1500C-class steam cooling gas turbine and 1300C-class reheat cycle gas turbine combined cycle power generation systems. In addition, methane reforming cooling method and NO reducing catalytic reheater are proposed. Based on these findings, the Maximized efficiency Optimized Reheat cycle Innovative Gas Turbine Combined cycle (MORITC) Power Generation System with the most effective combination of advanced technologies and the new devices have been proposed. In case of the proposed reheat cycle gas turbine with pressure ratio being 55, the high pressure turbine inlet temperature being 1700C, the low pressure turbine inlet temperature being 800C, combined with the ultra super critical pressure, double reheat type heat recovery Rankine cycle, the thermal efficiency of combined cycle are expected approximately 66.7% (LHV, generator end).

scholarly journals A Double-Bed Adsorptive Heat Transformer for Upgrading Ambient Heat: Design and First Tests

Energies ◽  
2019 ◽  
Vol 12 (21) ◽  
pp. 4037 ◽  
Author(s):  
Mikhail Tokarev
Keyword(s):  
Steady State ◽  
Heat Generation ◽  
Power Output ◽  
Thermal Efficiency ◽  
Natural Source ◽  
Specific Power ◽  
Specific Power Output ◽  
Heat Transformer ◽  
Continuous Heat ◽  
Steady State Cycling

A full scale lab prototype of an adsorptive heat transformer (AHT), consisting of two adsorbers, an evaporator, and a condenser, was designed and tested in subsequent cycles of heat upgrading. The composite LiCl/SiO2 was used as an adsorbent with methanol as an adsorbtive substance under boundary temperatures of TL/TM/TH = −30/20/30 °C. Preliminary experiments demonstrated the feasibility of the tested AHT in continuous heat generation, with specific power output of 520 W/kg over 1–1.5 h steady-state cycling. The formal and experimental thermal efficiency of the tested rig were found to be 0.5 and 0.44, respectively. Although the low potential heat to be upgraded was available for free from a natural source, the electric efficiency of the prototype was found to be as high as 4.4, which demonstrates the promising potential of the “heat from cold” concept. Recommendations for further improvements are also outlined and discussed in this paper.

Development of an 8MW-Class High-Efficiency Gas Turbine, M7A-03

2007 ◽  
Author(s):  
Kazuhiko Tanimura ◽  
Naoki Murakami ◽  
Akinori Matsuoka ◽  
Katsuhiko Ishida ◽  
Hiroshi Kato ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Thermal Efficiency ◽  
High Performance ◽  
High Efficiency ◽  
High Reliability ◽  
Pressure Ratio ◽  
Combined Cycle ◽  
Gas Temperature ◽  
Turbine Cooling ◽  
Distributed Power Generation

The M7A-03 gas turbine, an 8 MW class, single shaft gas turbine, is the latest model of the Kawasaki M7A series. Because of the high thermal efficiency and the high exhaust gas temperature, it is particularly suitable for distributed power generation, cogeneration and combined-cycle applications. About the development of M7A-03 gas turbine, Kawasaki has taken the experience of the existing M7A-01 and M7A-02 series into consideration, as a baseline. Furthermore, the latest technology of aerodynamics and cooling design, already applied to the 18 MW class Kawasaki L20A, released in 2000, has been applied to the M7A-03. Kawasaki has adopted the design concept for achieving reliability within the shortest possible development period by selecting the same fundamental engine specifications of the existing M7A-02 – mass air flow rate, pressure ratio, TIT, etc. However, the M7A-03 has been attaining a thermal efficiency of greater than 2.5 points higher and an output increment of over 660 kW than the M7A-02, by the improvement in aerodynamic performance of the compressor, turbine and exhaust diffuser, improved turbine cooling, and newer seal technology. In addition, the NOx emission of the combustor is low and the M7A-03 has a long service life. These functions make long-term continuous operation possible under various environmental restraints. Lower life cycle costs are achieved by the engine high performance, and the high-reliability resulting from simple structure. The prototype M7A-03 gas-turbine development test started in the spring of 2006 and it has been confirmed that performance, mechanical characteristics, and emissions have achieved the initial design goals.

Heat-Exchanged Propulsion Gas Turbines: A Candidate for Future Lower SFC and Reduced-Emission Military and Civil Aeroengines

2009 ◽  
Author(s):  
Colin F. McDonald ◽  
Colin Rodgers
Keyword(s):  
Gas Turbines ◽  
High Efficiency ◽  
Pressure Ratio ◽  
Thermodynamic Cycle ◽  
Simple Cycle ◽  
Specific Power ◽  
Operational Experience ◽  
Fuel Cost ◽  
Turbofan Engines ◽  
Fuel Burn

After seven decades of service the evolution of simple cycle propulsion gas turbines continues with emphasis now being placed on reduced fuel burn, lower emissions, and less noise. With compressor and turbine efficiencies near plateauing, and turbine inlet temperatures paced by materials and blade cooling technologies, improvements in SFC, specific power and weight for conventional engines (including small turboprop, and turboshaft engines and larger turbofans) will likely be incremental compared with the past. With retention of the simple cycle both evolutionary and revolutionary approaches are being taken by the aeroengine industry to improve performance, particularly reduced fuel burn in an era of high fuel cost. In this paper a further step is suggested, that is in concert with meeting performance, economic, and environmental goals of future aeroengines, namely the use of a more complex thermodynamic cycle involving recuperation for turboprop and turboshaft engines, and intercooling together with recuperation for higher pressure ratio turbofan engines. The idea of heat exchanged propulsion gas turbines is not new, but the many concepts identified from studies done periodically over the last 65 years, including the few engines that were static tested and one test flown, didn’t find acceptance in an era of low fuel cost and concerns about recuperator integrity and reliability. With today’s very high fuel cost there is current interest in this type of engine because of its potential for low SFC and reduced emissions. In this paper potential applications are summarized and the features of various heat exchanged aeroengine design concepts together with projected performance are presented. Included is a discussion on the various issues that must be resolved before they enter service. A postulated deployment scenario is suggested with engines initially developed to meet military aviation needs, such as recuperated turboprop and turbofan engines for extended range UAV’s, followed by a recuperated turboshaft engine for a helicopter. Operational experience and demonstrated reliability from these would pave the way for high efficiency ICR turbofan engines for military and civil aircraft service sometime after the year 2020.

Optimum Cycle Parameters for Turbofan Engines

1970 ◽  
Author(s):  
W. C. Moffatt
Keyword(s):  
Simple Procedure ◽  
Pressure Ratio ◽  
Inlet Temperature ◽  
Closed Form Solutions ◽  
Turbofan Engines ◽  
Compressor Pressure Ratio ◽  
Temperature Component ◽  
Flow Through ◽  
Specific Thrust ◽  
Bypass Ratio

This paper presents closed-form solutions for optimum compressor pressure ratio, bypass ratio and fan pressure ratio, given the turbine inlet temperature, component efficiencies and flight Mach number for a turbofan engine. In addition a simple procedure is outlined for obtaining the optimum combination of these quantities and a sample calculation is included. The optimum condition is defined as that which maximizes the specific thrust (thrust per pound per second of air flow through the gasifier) of the engine. The effects of differing gas properties in different portions of the engine are included in the analysis.

Disappearing Thermo-Economic Sanity in Gas Turbine Combined Cycle Ratings: A Critique

2019 ◽  
Author(s):  
S. Can Gülen
Keyword(s):  
Gas Turbine ◽  
Thermal Efficiency ◽  
Film Cooling ◽  
Pressure Ratio ◽  
Open Loop ◽  
Product Line ◽  
Combined Cycle ◽  
Inlet Temperature ◽  
Turbine Inlet ◽  
Steam Turbine Condenser

Abstract There is very little doubt that there has been a noticeable advance in heavy-duty industrial gas turbine technology for utility scale electric power generation in the last decade. In keeping with the first six decades of the technology (roughly 1950 through 2010), the main drivers in increasing thermal efficiency and megawatt ratings have been increasing turbine inlet temperature and airflow. In accordance with the basic thermodynamic principles governing the underlying Brayton cycle, compressor pressure ratio kept pace with them. It is hard to quibble about the 40+ percent in rated thermal efficiency in simple cycle. If projected turbine inlet temperatures and cycle pressure ratios can be sustained in the field, current state-of-the-art in turbine hot gas path metallurgy, coatings and advanced film cooling techniques indeed support published ratings. Unfortunately, published combined cycle ratings are an altogether different matter. It is one thing to set the product line rating performance at an aggressive level with well-understood albeit optimistic assumptions such as very low water-cooled steam turbine condenser pressure with open-loop cooling. It is yet another thing to blatantly disregard fundamental laws of thermodynamics with outlandish performance ratings, which are unlikely to materialize even in the next decade or two cost-effectively (unless an unforeseen transformative step-change in technology materializes). In this paper, using fundamental thermodynamic arguments and detailed heat and mass balance simulations, it will be shown that some, if not all, OEM ratings are losing touch with reality.

Effects of Water and Steam Injection on Thermodynamic Performance of Gas-Turbine Systems

2011 ◽  
Vol 110-116 ◽  
pp. 2109-2116 ◽  
Author(s):  
Kyoung Hoon Kim
Keyword(s):  
Gas Turbine ◽  
Thermal Efficiency ◽  
Pressure Ratio ◽  
Steam Injection ◽  
Specific Power ◽  
Co2 Gas ◽  
Thermodynamic Performance ◽  
System Variables ◽  
Important System ◽  
Injection Ratio

The water and steam injection gas-turbine systems are comparatively investigated. Thermodynamic performances of the regenerative after-fogging gas-turbine (RAF) system, steam-injection gas-turbine (STIG) system, and the regenerative steam-injection gas-turbine (RSTIG) system are analyzed parametrically. Using the analytic model, the important system variables such as thermal efficiency, fuel consumption, specific power, and specific emission of CO2 gas are evaluated in terms of pressure ratio and water or steam injection ratio. The numerical results show that water or steam injection results in a notable enhancement of thermal efficiency and specific power.

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