scholarly journals Energy and Exergy Analysis of a Simple Gas Turbine Cycle with Wet Compression

2018 ◽  
Vol 8 (1) ◽  
pp. 30 ◽  
Author(s):  
E. H. Betelmal ◽  
S. A. Farhat
Keyword(s):  
Gas Turbine ◽  
Water Injection ◽  
Analytical Formula ◽  
Heat Rate ◽  
Performance Model ◽  
Exergy Destruction ◽  
Isentropic Compression ◽  
Turbine Efficiency ◽  
Wet Compression ◽  
Gas Turbine Cycle

A thermodynamic model of the wet compressor in a simple gas turbine cycle was investigated in this paper. A suitable quantity of water was injected into the compressor-stages where it evaporated. Subsequently, the steam and air were heated in the combustion chamber and expanded in the turbine. The wet compressor (WC) has become a reliable way to reduce gas emissions and increase gas turbine efficiency. In this study, the operational data of the simple gas turbine and the maximum amount of water that can be injected into the compressor were assessed, as well as a comparison between the dry compression, the wet compression and the isentropic compression. The performance variation due to water spray in the compressor and the effect of varying ambient temperature on the performance of gas turbine (thermal efficiency, power) was investigated, and the results are compared to the results of the same cycle with a dry compressor. The analytical formula of exergy destruction and results show that exergy destruction increases with water injection. The programming of the performance model for the gas turbine was developed utilizing the software IPSEpro. The results of the gas turbine with a wet compressor demonstrates a 12% reduction in the compressor exit temperature up to isentropic temperature. The compressor work decreased by 11% when using a wet compressor, this lead to an improvement in power output and efficiency However, the wet compressor increases the specific fuel consumption and heat rate of the gas turbine. There are limitations in the amount of steam that can be injected, 0.4 kg/s of water was the optimum amount injected into the compressor.

Effects of Wet Compression on Performance of Regenerative Gas Turbine Cycle with Turbine Blade Cooling

2012 ◽  
Vol 224 ◽  
pp. 256-259
Author(s):  
Kyoung Hoon Kim ◽  
Kyoung Jin Kim ◽  
Hyung Jong Ko
Keyword(s):  
Gas Turbine ◽  
Turbine Blade ◽  
Thermal Efficiency ◽  
Water Injection ◽  
Specific Power ◽  
Turbine Blade Cooling ◽  
Blade Cooling ◽  
Wet Compression ◽  
System Variables ◽  
Gas Turbine Cycle

When water is injected at an inlet of compressor, wet compression occurs due to evaporation of water droplets. In this work, the effects of wet compression on the performance of regenerative gas turbine cycle with turbine blade cooling are analytically investigated. For various pressure ratios and water injection ratios, the important system variables such as ratio of coolant flow for turbine blade cooling, fuel consumption, specific power and thermal efficiency are estimated. Parametric studies show that wet compression leads to significant enhancement in both specific power and thermal efficiency in gas turbine systems with turbine blade cooling.

Multi-Objective Approach in Exergoeconomic and Environmental Optimization of the Gas Turbine Cycle

2011 ◽  
Vol 110-116 ◽  
pp. 2023-2029
Author(s):  
S. Ranjbar ◽  
H. Ajam ◽  
M. Eslamirasekh
Keyword(s):  
Gas Turbine ◽  
Production Cycle ◽  
Comparison Function ◽  
Exergy Destruction ◽  
Objective Functions ◽  
Turbine Efficiency ◽  
Design Variables ◽  
Two Stages ◽  
Gas Turbine Cycle ◽  
Compressor Efficiency

The gas turbine cycle either as an individual power production cycle or as a part of yet another cycle, is one of the most common industrials till now which, has been ever evaluated and analyzed. In the present research, this cycle has been modeled individually along with a pre-heater and a compressor at two stages with the objective to maximize the exergic efficiency and in the meantime decreasing the costs and environmental pollution. In addition, the isentropic turbine efficiency, the isentropic compressor efficiency, the ratio of the total pressure of the cycle, and the percentage of extra air has been defined as the design variables. Two objective functions are evaluated to be optimized by the genetic algorithm using the Pareto fitness approach as the determining comparison function. Finally, the exergo-economic coefficient of the related components and the amount of their exergy destruction and cost, at the optimum point, has been compared.

scholarly journals Energy and exergy analysis of a simple gas turbine combined with linde cycle and N2 injected into the compressor of the gas turbine

2021 ◽  
Vol 1 (1) ◽  
pp. 006-015
Author(s):  
E. H. Betelmal ◽  
A. M. Naas ◽  
A. Mjani
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Exergy Analysis ◽  
Air Separation ◽  
Compression Process ◽  
Turbine Efficiency ◽  
Performance Variation ◽  
Energy And Exergy ◽  
Energy And Exergy Analysis ◽  
Gas Turbine Cycle

In this paper, we investigated a thermodynamic model of the regeneration gas turbine cycle with nitrogen supplied during the compression process. A suitable quantity of nitrogen that comes from the air separation cycle (Linde cycle) is injected between the stages of the compressor where it is evaporated, then the nitrogen and air mixture enters into the combustion chamber where it is burned and expanded in the turbine. We used this method to reduce greenhouse gases and improve gas turbine efficiency. In this work, we evaluated the operational data of the regeneration gas turbine cycle and the maximum amount of nitrogen that can be injected into the compressor. We also investigated the performance variation due to nitrogen spray into the compressor, and the effect of varying ambient temperature on the performance of gas turbines (thermal efficiency, power), as well as a comparison between the normal gas turbine cycle, and the remodelled compression cycle. The exergy analysis shows that the injection of the nitrogen will increase exergy destruction. The results demonstrated an 8% increase in the efficiency of the cycle, furthermore, CO2 emission decreased by 11% when the nitrogen was injected into the compressor.

Comparative Energy and Exergy Analysis of Proposed Gas Turbine Cycle With Simple Gas Turbine Cycle at Same Operational Cost

2019 ◽  
Author(s):  
M. N. Khan ◽  
Ibrahim M. Alarifi ◽  
I. Tlili
Keyword(s):  
Gas Turbine ◽  
Fuel Consumption ◽  
Exergy Analysis ◽  
Pressure Ratio ◽  
Specific Fuel Consumption ◽  
Exergy Destruction ◽  
Energy And Exergy ◽  
Energy And Exergy Analysis ◽  
Gas Turbine Cycle ◽  
The Impact

Abstract Environmentally friendly and effective power systems have been receiving increased investigation due to the aim of addressing global warming, energy expansion, and economic growth. Gas turbine cycles are perceived as a useful technology that has advanced power capacity. In this research, a gas turbine cycle has been proposed and developed from a simple and regenerative gas turbine cycle to enhance performance and reduce Specific fuel consumption. The impact of specific factors regarding the proposed gas turbine cycle on thermal efficiency, net output, specific fuel consumption, and exergy destruction, have been inspected. The assessments of the pertinent parameters were performed based on conventional thermodynamic energy and exergy analysis. The results obtained indicate that the peak temperature of the Proposed Gas Turbine Cycle increased considerably without affecting fuel consumption. The results show that at Pressure Ratio (rp = 6) the performance of the Proposed Gas Turbine Cycle is much better than Single Gas Turbine Cycle but the total exergy destruction of Proposed Gas Turbine Cycle higher than the SGTC.

A Combined Small Modular Reactor and Gas Turbine Cycle With Reheat

2018 ◽  
Author(s):  
Robert Stakenborghs ◽  
Gregory Kramer
Keyword(s):  
Gas Turbine ◽  
Heat Rate ◽  
Combined Cycle ◽  
Net Generation ◽  
Power Station ◽  
Small Modular Reactor ◽  
Gas Turbine Exhaust ◽  
Main Steam ◽  
Unit Output ◽  
Gas Turbine Cycle

A novel combined small modular reactor (SMR) and gas turbine cycle is presented. This SMR-GT cycle is modeled using fundamental thermodynamic relationships and compared to existing state-of-the-art power generation cycles. The SMR-GT cycle includes an 82 MWe SMR cycle that is combined with a 54 MWe gas turbine cycle. A heat exchanger is used to extract energy from the gas turbine exhaust to create superheated main steam and provide reheat downstream of the LP turbine. This results in a 32 MWe increase in the SMR cycle for total unit output of 136 MWe. Comparisons of thermal efficiency, heat rate, CO2 emissions, and net generation are made between a stand-alone SMR, a typical combined cycle gas turbine (CCGT), standalone gas turbine and the combined SMR-GT cycles. Several advantages of the SMR-GT cycle are discussed. In addition, the rapid deployment of a gas turbine allows for a power station to deliver power and earn revenue prior to completion of the more complex SMR portion of the plant. The SMR portion of the cycle also reduces the overall fuel cost volatility associated with gas turbine based power station.

Semi-Closed Gas Turbine/Combined Cycle With Water Recovery and Extensive Exhaust Gas Recirculation

1996 ◽  
Author(s):  
Bruno Facchini ◽  
Daniele Fiaschi ◽  
Giampaolo Manfrida
Keyword(s):  
Gas Turbine ◽  
Water Injection ◽  
Combined Cycle ◽  
Point Of View ◽  
Exhaust Gas ◽  
Water Recovery ◽  
Gas Treatment ◽  
High Level ◽  
Gas Recirculation ◽  
Gas Turbine Cycle

This innovative gas turbine cycle can offer several advantages over conventional cycles from the point of view of environmental friendship. The basic idea of SCGT/CC (Semi-Closed Gas Turbine/Combined Cycle with water recovery) is to cool down the exhaust temperatures to allow full condensation of the water vapor, and recirculate a large part of the exhaust gases to the compressor. The condensed water can then be reinjected by means of a pump at compressor delivery. The working gas composition is thus close to that corresponding to stoichiometric combustion, which opens the possibility of applying techniques for CO2 recycling and general exhaust gas treatment. An increase in work output is connected to water injection, while a high level of efficiency is maintained as the compressor work is reduced and the cycle parameters are tuned for the exhaust of this turbine.

Formation Process of Water Film and Performance Effect on Compressor Stage

2016 ◽  
Author(s):  
Hai Zhang ◽  
Xiaojiang Tian ◽  
Xiaojun Pan ◽  
Jie Zhou ◽  
Qun Zheng
Keyword(s):  
Gas Turbine ◽  
Formation Process ◽  
Water Injection ◽  
Water Film ◽  
Compressor Stage ◽  
Blade Surface ◽  
Water Droplets ◽  
Compression Process ◽  
Turbine Performance ◽  
Wet Compression

In process of wet compression, gas turbine engine will ingest a certain amount of water, which can influence the overall performance of the engine. This phenomenon is particularly significant in the cleaning process of industrial gas turbine and water injection of aero-engine. When the quantity of water ingestion is quite large, the performance of gas turbine will appear deterioration and may lead to flameout, power reduce or even shutdown of the engine, causing accidents. Water droplets will be accumulated on the blade surface where water films could be formed on pressure surface in the wet compression process. The effects of water film on gas turbine engines are aerodynamic, thermodynamic and mechanical. The above-mentioned effects occur simultaneously and be affected by each other. Considering the above effects and the fact that they are time dependent, there are few gas turbine performance researches, which take into account the water film phenomenon. This study is a new research of investigating theoretically the water film effects on a gas turbine performance. It focuses on the aerodynamic and thermodynamic effects of the phenomenon on the compressor stage. The computation of water film thickness, which frequently be formed on the surface of compressor blade, its movement and extra torque demand, are provided by a simulation model of the code. Considering the change in blade’s profile and the thickness feature of the water film, the compressor stage’s performance deterioration is analyzed. In addition to this, movement and the formation of the water film on a compressor stage are simulated and analyzed by using unsteady numerical methods under different water injecting conditions in this paper. The movement characteristics of water droplets in compressor passage are investigated to understand the flow mechanisms responsible for water film formation process. The forming and the tearing process of water film on blade surface are analyzed at different injection conditions. For simulating the real situation, The maximum quantity of injected water can reach 12%. The results indicate that continuity and region of the water film on the blade surface will be developed with the increment of droplet size and injection rate. It is also found that the flow losses near blade surface increases with the tearing process of water film due to the increment of surface roughness.

scholarly journals 100 MW Combined Cycle Achieves 7000 BTU/KWH Heat Rate at JFK International Airport

1992 ◽  
Author(s):  
Donald A. Kolp ◽  
Richard Roberts ◽  
Soo Young Kim
Keyword(s):  
Gas Turbine ◽  
Heat Recovery ◽  
Waste Heat ◽  
Water Injection ◽  
Heat Rate ◽  
Combined Cycle ◽  
Dual Function ◽  
Electric Generator ◽  
International Airport ◽  
Gas Fuel

In early 1994 a 100 MW LM6000 combined cycle cogeneration plant will begin operation at New York City’s John F. Kennedy International Airport. Thanks to the extremely high simple cycle efficiency of the LM6000 gas turbine (8200 BTU/KWH, 8650 kJ/KWH-LHV dry) and a sophisticated three-pressure steam generating system, a heat rate below 7000 BTU/KWH-LHV (7380 kJ/KWH-LHV) is expected when operating in combined cycle mode. The dual-spool LM6000 achieves its efficiency by means of a 30:1 compression ratio. 2100 F. (1149 C.) firing temperatures and the direct coupling of the low compressor/turbine rotor to the electric generator. The efficiency of the heat recovery steam generator results from the use of three economizers, three evaporators and two superheaters combined with a patented feedwater heating system which yields a 245 F. (118 C.) exhaust stack temperature. Operating flexibility is essential in this application. While the dual-fueled plant is designed for pure combined cycle operation, most of the time it will operate in a cogeneration mode — producing up to 250 × 106 BTU/HR (264 × 106 kJ/HR) of steam for heating in the winter and 7000 (24,618 KW) tons of chilling for air conditioning airport terminals in the summer. The waste heat boilers are designed to be supplementary fired on gas fuel when the airport requires the 110 MW maximum capacity of the plant simultaneously with the maximum thermal load of 250 × 106 BTU/HR (264 × 106 kJ/HR). NOx emissions are controlled with a combination of water injection in the turbine combustors and a dual-function catalyst SCR/CO converter. CO is controlled by means of the converter. Combined gas turbine and duct burner NOx is maintained below 9.0 PPMV dry (@ 15% O2) and CO below 1.5 PPH (0.68 KG/HR) dry (@ 15% O2) when operating on gas fuel. Cycle details, equipment selection and operation as well as the plant economics provide a useful insight into the benefits of these recent developments in gas turbine and heat recovery combined cycle cogeneration technology.

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.

Results of the First Application of the SwirlFlash™ Wet Compression System on a 150MW Heavy-Duty Gas Turbine

2005 ◽  
Author(s):  
Michae¨l Deneve ◽  
Bernard De Tandt ◽  
Niko Cornelis ◽  
Christiaan Bultereys ◽  
Sigrid Gijbels
Keyword(s):  
Gas Turbine ◽  
Power Output ◽  
Gas Flow ◽  
Heat Rate ◽  
Injection System ◽  
Alpha Power ◽  
Compression System ◽  
Discharge Temperature ◽  
Compressor Work ◽  
Wet Compression

In general, the compressor takes approximately 2/3 of the expansion work delivered by the turbine. Any reduction of compressor work would improve the power output of the gas turbine. One way of doing this is to inject an amount of water in the inlet air. The amount of water that can be absorbed by the air is limited due to the relative humidity. The SwirlFlash™ system of Alpha Power Systems is an over-spray injection system, which delivers an over-saturated mixture to the compressor. Adiabatic compression will heat up the mixture and the water will evaporate inside the compressor. The heat required for evaporation will cool down the air, which results in a lower compressor discharge temperature. This lower discharge temperature leads to a reduction of compressor work. The lower compressor work and the increased fuel flow will raise the gas turbine power output. This paper is the result of the evaluation of the SwirlFlash™ system installed at the Herdersbrug power plant of Electrabel Belgium. The wet compression system was commissioned in 2003. In this paper, the principle of the wet compression system and the Herdersbrug installation are described as well as the influence of this system on several parameters such as the compressor discharge temperature, the gas flow, the steam production, the power gain and the heat rate. The influence on the emissions, humming and the interference with anti-icing are also discussed. Finally, the material related aspects and the vibration behavior are treated.

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