Parametric Analysis of Combined Gas-Steam Cycles

1982 ◽  
Author(s):  
G. Cerri
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Parametric Analysis ◽  
State Of The Art ◽  
Pressure Ratio ◽  
The State ◽  
Point Of View ◽  
Compressed Air ◽  
Specific Work ◽  
Maximal Efficiency

Combined gas-steam cycles have been analyzed from the thermodynamic point of view. Suitable thermodynamics indices — explained in Appendix A — have been utilized. The parameters that most influence efficiency have been singled out and their ranges of variability have been specified. Calculations have been carried out — see Appendix B — taking into account the state of the art for gas turbines and the usual values for the quantities of steam cycles. The results are given. The maximal gas turbine temperature has been varied between 800°C and 1400°C. The gas turbine pressure ratio has been analyzed in the range of 2–24. Afterburning has also been taken into consideration. Maximal efficiency curves and the corresponding specific work curves (referred to the compressed air) related to the parameters of the analysis are given and discussed.

Parametric Analysis of Combined Gas-Steam Cycles

1987 ◽  
Vol 109 (1) ◽  
pp. 46-54 ◽  
Author(s):  
G. Cerri
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Parametric Analysis ◽  
State Of The Art ◽  
Pressure Ratio ◽  
The State ◽  
Point Of View ◽  
Compressed Air ◽  
Specific Work ◽  
Maximal Efficiency

Combined gas-steam cycles have been analyzed from the thermodynamic point of view. Suitable thermodynamics indices—explained in Appendix A—have been utilized. The parameters that most influence efficiency have been singled out and their ranges of variability have been specified. Calculations have been carried out—see Appendix B—taking into account the state of the art for gas turbines and the usual values for the quantities of steam cycles. The results are given. The maximal gas turbine temperature has been varied between 800°C and 1400°C. The gas turbine pressure ratio has been analyzed in the range of 2–24. Afterburning has also been taken into consideration. Maximal efficiency curves and the corresponding specific work curves (referred to the compressed air) related to the parameters of the analysis are given and discussed.

Gas Turbines with Heat Exchanger and Water Injection in the Compressed Air

1970 ◽  
Vol 185 (1) ◽  
pp. 953-961 ◽  
Author(s):  
N Gašparović ◽  
J. G. Hellemans
Keyword(s):  
Heat Exchanger ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Pressure Ratio ◽  
Water Injection ◽  
Compressed Air ◽  
Specific Work ◽  
Turbine Inlet ◽  
Higher Temperature ◽  
Gas Turbine Cycle

Water injection into the compressed air between the compressor and the heat exchanger of a gas turbine plant represents only one of various possible methods of introducing water into a gas turbine cycle. With this process, it is advantageous to inject just sufficient water to produce saturation of the compressed air with water vapour. Assuming that the same size of heat exchanger is used, the following changes are introduced as compared with a gas turbine cycle without water injection. The efficiency is increased to an extent equivalent to raising the temperature at the turbine inlet by 100 degC. The gain in specific work is still greater. It attains values which can only be achieved with about 140 degC higher temperature at the turbine inlet. With a normal size of heat exchanger, the water consumption is about 6–8 per cent of the mass flow of air. This rate of consumption is not high enough to introduce any detrimental side effects in the cycle. Special water treatment is not necessary. The performance of existing designs or installations without a heat exchanger can be improved by adding a heat exchanger and water injection without necessitating any change in pressure ratio.

scholarly journals Impact of compressed air energy storage demands on gas turbine performance

2020 ◽  
pp. 095765092090627 ◽  
Author(s):  
Uyioghosa Igie ◽  
Marco Abbondanza ◽  
Artur Szymański ◽  
Theoklis Nikolaidis
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Pressure Ratio ◽  
Engine Performance ◽  
Compressed Air ◽  
Design Stage ◽  
Simulation Code ◽  
Ratio Distribution ◽  
Stall Margin ◽  
Industrial Gas Turbines

Industrial gas turbines are now required to operate more flexibly as a result of incentives and priorities given to renewable forms of energy. This study considers the extraction of compressed air from the gas turbine; it is implemented to store heat energy at periods of a surplus power supply and the reinjection at peak demand. Using an in-house engine performance simulation code, extractions and injections are investigated for a range of flows and for varied rear stage bleeding locations. Inter-stage bleeding is seen to unload the stage of extraction towards choke, while loading the subsequent stages, pushing them towards stall. Extracting after the last stage is shown to be appropriate for a wider range of flows: up to 15% of the compressor inlet flow. Injecting in this location at high flows pushes the closest stage towards stall. The same effect is observed in all the stages but to a lesser magnitude. Up to 17.5% injection seems allowable before compressor stalls; however, a more conservative estimate is expected with higher fidelity models. The study also shows an increase in performance with a rise in flow injection. Varying the design stage pressure ratio distribution brought about an improvement in the stall margin utilized, only for high extraction.

scholarly journals Large Helium Turbines for Nuclear Power Plants

1970 ◽  
Author(s):  
W. Endres
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
State Of The Art ◽  
Short Review ◽  
The State ◽  
Closed Cycle ◽  
The Future

A short review of the state-of-the-art of the closed cycle gas turbine technology is given and the future requirements for large helium turbines are described. The necessary development of components and turbine sizes is outlined. In a second part of the paper the configuration and layout of power plants with gas turbines are discussed.

scholarly journals Ideal Power Output — An Alternative Aircraft Engine Performance Comparator

1997 ◽  
Author(s):  
Marvin F. Schmidt ◽  
Christopher M. Norden ◽  
Jeffrey M. Stricker
Keyword(s):  
Gas Turbine ◽  
Power Output ◽  
State Of The Art ◽  
Pressure Ratio ◽  
Engine Performance ◽  
Aircraft Engine ◽  
The State ◽  
Power Cycle ◽  
Shaft Power ◽  
Bypass Ratio

The gas turbine is applied in four basic configurations; the turbojet, the turbofan, the turboprop and the turboshaft. Comparisons of the performance of these various configurations is difficult since they convert the energy to different forms, i.e. thrust or shaft power. Cycle variables which do not necessarily constitute advancements in the state-of-the-art such as bypass ratio and fan pressure ratio can have a profound effect on thrust and shaft power. Differences in flight speed and altitude capability further confound the comparisons. What is required is a comparison methodology that removes all of these variables and yet puts all the various types of engines on an equitable basis. This paper will provide such a comparison tool. All turbomachinery, regardless of configuration, can be compared with this method.

Performance of Integrated Combined and Cogeneration Cycles Using Latest Gas Turbines

2004 ◽  
Author(s):  
Sanjay ◽  
Onkar Singh ◽  
B. N. Prasad
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Pressure Ratio ◽  
Utilization Efficiency ◽  
Inlet Temperature ◽  
Air Cooling ◽  
Specific Work ◽  
Fuel Utilization ◽  
Compressor Pressure Ratio ◽  
Cogeneration Cycle

The paper deals with the thermodynamic performance of combined and cogeneration cycles using the state of the art gas turbines. A configuration has been conceptualized using the latest gas turbine MS9001H that uses steam to cool the hot gas path components. In order to study the effect of cooling means, the same gas turbine is subjected to transpiration air cooling. Using the above mentioned conceptualized topping cycle, the bottoming cycle selected consists of a two-pressure reheat heat recovery steam generator (HRSG) with reheat having two options. First option is the integrated system (IS), which is a combined/cogeneration cycle, and the other is called the normal cogeneration cycle (NC). Both of these cycles are subjected to steam and transpiration air-cooling. The cycle performance is predicted based on parameteric study which has been carried out by modeling the various elements of cycle such as gas, compressor combustor, cooed gas turbine, HRSG steam turbine, condenser, etc. The performance is predicted for parameters such as fuel utilization efficiency (ηf), power-to-heat-ratio (PHR), coolant flow requirements, plant specific work, etc. as a function of independent parameters such as compressor pressure ratio (rpc) and turbine inlet temperature (TIT), etc. The results predicted will be helpful for designers to select the optimum compressor pressure ratio and TIT to achieve the target fuel utilization efficiency, and PHR at the target plant specific work.

Advanced Combined Cycle Alternatives With the Latest Gas Turbines

1996 ◽  
Author(s):  
P. J. Dechamps
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Heat Recovery ◽  
Power Plants ◽  
Combined Cycle ◽  
Point Of View ◽  
Specific Work ◽  
Turbine Cooling ◽  
Exhaust Temperature ◽  
Industrial Gas Turbine

The last decade has seen remarkable improvements in industrial gas turbine size and performances. There is no doubt that the coming years are holding the promises of even more progress in these fields. As a consequence, the fuel utilization achieved by combined cycle power plants has been steadily increased. This is however also because of the developments in the heat recovery technology. Advances on the gas turbine side justify the development of new combined cycle schemes, with more advanced heat recovery capabilities. Hence, the system performance is spiralling upwards. In this paper, we look at some of the heat recovery possibilities with the newly available gas turbine engines, characterized by a high exhaust temperature, a high specific work, and the integration of some gas turbine cooling with the boiler. The schemes range from classical dual pressure systems, to triple pressure systems with reheat in supercritical steam conditions. For each system, an optimum set of variables (steam pressures, etc) is proposed. The effect of some changes on the steam cycle parameters, like increasing the steam temperatures above 570°C are also considered. Emphasis is also put on the influence of some special features or arrangements of the heat recovery steam generators, not only from a thermodynamic point of view.

Thermodynamic Evaluation of Advanced Combined Cycle Using Latest Gas Turbine

2003 ◽  
Author(s):  
Sanjay ◽  
Onkar Singh ◽  
B. N. Prasad
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Pressure Ratio ◽  
Combined Cycle ◽  
Inlet Temperature ◽  
Specific Work ◽  
Thermodynamic Evaluation ◽  
Compressor Pressure Ratio ◽  
Steam Cooling ◽  
Plant Efficiency

The present work deals with the thermodynamic evaluation of combined cycle with re-heat in gas turbine using the latest gas turbines namely ABB GT26 gas turbine (advanced) in which reheat is used and the blade cooling is done by air bled from compressor. The same turbine is subjected to closed loop steam cooling. Parametric study has been performed on plant efficiency and specific work for various independent parameters such as turbine inlet temperature, compressor pressure ratio, reheating pressure ratio, reheater inlet temperature, blade temperature, etc.. It has been observed that due to higher compressor pressure ratio involved in reheat gas turbine combined cycle and higher temperature of exhaust, the plant efficiency and specific work are higher with the advanced reheat gas/steam combined cycle over the simple combined cycle. Steam cooling offers better performance over aircooling.

Thermodynamic Analysis of a Steam Injected and Recuperated Gas Turbine Air Compressor

2012 ◽  
Author(s):  
Matthew J. Blom ◽  
Ashley P. Wiese ◽  
Michael J. Brear ◽  
Chris Manzie ◽  
Anthony Kitchener
Keyword(s):  
Gas Turbine ◽  
Thermodynamic Analysis ◽  
Gas Turbines ◽  
Pressure Ratio ◽  
Significant Proportion ◽  
Steam Injection ◽  
Compressed Air ◽  
Promising Alternative ◽  
Air Compressor ◽  
Compact Size

Compressed air and steam are perhaps the most significant industrial utilities after electricity, gas and water, and are responsible for a significant proportion of global energy consumption. Microturbine technology, in the form of a Gas Turbine Air Compressor (GTAC), offers a promising alternative to traditional, electrically driven air compressors providing low vibration, a compact size, reduced electrical consumption and potentially reduced greenhouse gas emissions. With high exhaust temperatures, gas turbines are well suited to the cogeneration of steam. The compressed air performance can be further increased by injecting some of that cogenerated steam or by conventional recuperation. This paper presents a thermodynamic analysis of various forms of the GTAC cycle incorporating steam cogeneration, steam injection (STIGTAC) and recuperation. The addition of cogeneration leads to improved energy utilisation, while steam injection leads to a significant boost in both the compressed air delivery and efficiency. As expected, for a low pressure ratio device, recuperating the GTAC leads to a significant increase in efficiency. The combination of steam injection and recuperation forms a recuperated STIGTAC with increased compressed air performance over the unrecuperated STIGTAC at the expense of reduced steam production. Finally, an analysis using a simplified model of the STIGTAC demonstrates a significant reduction in CO2 emissions, when compared to an equivalent air compressor driven by primarily coal-based electricity and a natural gas fired boiler.

Advanced Combined Cycle Alternatives With the Latest Gas Turbines

1998 ◽  
Vol 120 (2) ◽  
pp. 350-357 ◽  
Author(s):  
P. J. Dechamps
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Heat Recovery ◽  
Power Plants ◽  
Combined Cycle ◽  
Point Of View ◽  
Specific Work ◽  
Turbine Cooling ◽  
Exhaust Temperature ◽  
Industrial Gas Turbine

The last decade has seen remarkable improvements in industrial gas turbine size and performances. There is no doubt that the coming years are holding the promise of even more progress in these fields. As a consequence, the fuel utilization achieved by combined cycle power plants has been steadily increased. This is, however, also because of the developments in the heat recovery technology. Advances on the gas turbine side justify the development of new combined cycle schemes, with more advanced heat recovery capabilities. Hence, the system performance is spiraling upward. In this paper, we look at some of the heat recovery possibilities with the newly available gas turbine engines, characterized by a high exhaust temperature, a high specific work, and the integration of some gas turbine cooling with the boiler. The schemes range from classical dual pressure systems, to triple pressure systems with reheat in supercritical steam conditions. For each system, an optimum set of variables (steam pressures, etc.) is proposed. The effect of some changes on the steam cycle parameters, like increasing the steam temperatures above 570°C are also considered. Emphasis is also put on the influence of some special features or arrangements of the heat recovery steam generators, not only from a thermodynamic point of view.

Sign in / Sign up

Export Citation Format

Share Document