Quality Key Numbers of Gas Turbine Combined Cycles

2021 ◽  
Author(s):  
Hans Wettstein
Keyword(s):  
Gas Turbine ◽  
Combined Cycles

Optimization of Advanced Liquid Natural Gas-Fuelled Combined Cycle Machinery Systems for a High-Speed Ferry

2012 ◽  
Author(s):  
Kari Anne Tveitaskog ◽  
Fredrik Haglind
Keyword(s):  
Gas Turbine ◽  
High Speed ◽  
Dynamic Network ◽  
Combined Cycle ◽  
Working Fluid ◽  
Power Requirement ◽  
Pressure Steam ◽  
Combined Cycles ◽  
Liquid Natural Gas ◽  
Steam Cycle

This paper is aimed at designing and optimizing combined cycles for marine applications. For this purpose, an in-house numerical simulation tool called DNA (Dynamic Network Analysis) and a genetic algorithm-based optimization routine are used. The top cycle is modeled as the aero-derivative gas turbine LM2500, while four options for bottoming cycles are modeled. Firstly, a single pressure steam cycle, secondly a dual-pressure steam cycle, thirdly an ORC using toluene as the working fluid and an intermediate oil loop as the heat carrier, and lastly an ABC with inter-cooling are modeled. Furthermore, practical and operational aspects of using these three machinery systems for a high-speed ferry are discussed. Two scenarios are evaluated. The first scenario evaluates the combined cycles with a given power requirement, optimizing the combined cycle while operating the gas turbine at part load. The second scenario evaluates the combined cycle with the gas turbine operated at full load. For the first scenario, the results suggest that the thermal efficiencies of the combined gas and steam cycles are 46.3% and 48.2% for the single pressure and dual pressure steam cycles, respectively. The gas ORC and gas ABC combined cycles obtained thermal efficiencies of 45.6% and 41.9%, respectively. For the second scenario, the results suggest that the thermal efficiencies of the combined gas and steam cycles are 53.5% and 55.3% for the single pressure and dual pressure steam cycles, respectively. The gas ORC and gas ABC combined cycles obtained thermal efficiencies of 51.0% and 47.8%, respectively.

Analysis of Intermediate Temperature Combined Cycles With a Carbon Dioxide Topping Cycle

2008 ◽  
Author(s):  
R. Chacartegui ◽  
D. Sa´nchez ◽  
F. Jime´nez-Espadafor ◽  
A. Mun˜oz ◽  
T. Sa´nchez
Keyword(s):  
Carbon Dioxide ◽  
Power Plant ◽  
Gas Turbine ◽  
High Efficiency ◽  
Solar Power ◽  
Combined Cycle ◽  
Inlet Temperature ◽  
Pressure Drops ◽  
Combined Cycles ◽  
Topping Cycle

The development of high efficiency solar power plants based on gas turbine technology presents two problems, both of them directly associated with the solar power plant receiver design and the power plant size: lower turbine intake temperature and higher pressure drops in heat exchangers than in a conventional gas turbine. To partially solve these problems, different configurations of combined cycles composed of a closed cycle carbon dioxide gas turbine as topping cycle have been analyzed. The main advantage of the Brayton carbon dioxide cycle is its high net shaft work to expansion work ratio, in the range of 0.7–0.85 at supercritical compressor intake pressures, which is very close to that of the Rankine cycle. This feature will reduce the negative effects of pressure drops and will be also very interesting for cycles with moderate turbine inlet temperature (800–1000 K). Intercooling and reheat options are also considered. Furthermore, different working fluids have been analyzed for the bottoming cycle, seeking the best performance of the combined cycle in the ranges of temperatures considered.

Comparative Analysis of Different Inlet Air Cooling Technologies Including Solar Energy to Boost Gas Turbine Combined Cycles in Hot Regions

2018 ◽  
Vol 140 (11) ◽  
Author(s):  
Ahmed Abdel Rahman ◽  
Esmail M. A. Mokheimer
Keyword(s):  
Comparative Analysis ◽  
Gas Turbine ◽  
Output Power ◽  
Power Output ◽  
Combined Cycle ◽  
Air Cooling ◽  
Absorption Chiller ◽  
Absorption Chillers ◽  
Combined Cycles ◽  
Net Power Output

Cooling the air before entering the compressor of a gas turbine of combined cycle power plants is an effective method to boost the output power of the combined cycles in hot regions. This paper presents a comparative analysis for the effect of different air cooling technologies on increasing the output power of a combined cycle. It also presents a novel system of cooling the gas turbine inlet air using a solar-assisted absorption chiller. The effect of ambient air temperature and relative humidity on the output power is investigated and reported. The study revealed that at the design hour under the hot weather conditions, the total net power output of the plant drops from 268 MW to 226 MW at 48 °C (15.5% drop). The increase in the power output using fogging and evaporative cooling is less than that obtained with chillers since their ability to cool down the air is limited by the wet-bulb temperature. Integrating conventional and solar-assisted absorption chillers increased the net power output of the combined cycle by about 35 MW and 38 MW, respectively. Average and hourly performance during typical days have been conducted and presented. The plants without air inlet cooling system show higher carbon emissions (0.73 kg CO2/kWh) compared to the plant integrated with conventional and solar-assisted absorption chillers (0.509 kg CO2/kWh) and (0.508 kg CO2/kWh), respectively. Also, integrating a conventional absorption chiller shows the lowest capital cost and levelized electricity cost (LEC).

GTPRO: A Flexible, Interactive Computer Program for the Design and Optimization of Gas Turbine Power Systems

1988 ◽  
Author(s):  
Maher A. Elmasri
Keyword(s):  
Power Systems ◽  
Computer Program ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Combined Cycle ◽  
Process Flow ◽  
Technical Parameters ◽  
Design And Optimization ◽  
Trade Offs ◽  
Combined Cycles

A fast, interactive, flexible computer program has been developed to facilitate system selection and design for gas turbine based power and cogeneration plants. A data base containing ISO performance information on forty-two gas turbines is coupled to an off-design model to predict engine characteristics for different site and installation parameters. A heat recovery steam generator (HRSG) model allows boiler size and cost to be estimated as a function of the system’s technical parameters. The model can handle HRSG’s with up to two live steam pressures plus a third feedheating/deaerating drum. Five basic types of combined cycle are covered with up to four different process steam streams for cogeneration or gas turbine injection. Two additional feedheating steam bleeds are supported for condensing combined cycles. The program is intelligent with some internal decision making capabilities regarding process steam sourcing and flow directions and will automatically select the appropriate heat and mass balance procedures to cover a wide variety of process flow schematics. The program provides plotter outputs to show the cycle process flow schematic, T-s and h-s diagrams, and HRSG temperature profiles. An application of GTPRO in analyzing some technical and economic performance trade-offs for two-pressure combined cycles is presented.

Comparative Investigation of Advanced Combined Cycles

2006 ◽  
Author(s):  
Hiwa Khaledi ◽  
Kazem Sarabchi
Keyword(s):  
Gas Turbine ◽  
Heat Recovery ◽  
Air Cooling ◽  
Actual Behavior ◽  
Exhaust Temperature ◽  
Blade Cooling ◽  
Large Influence ◽  
Combined Cycles ◽  
Cooling Technology ◽  
Turbine Exhaust

Combined cycles, at present, have a prominent role in the power generation and advanced combined cycles efficiencies have now reached to 60 percent. Examination of thermodynamic behavior of these cycles is still carried out to determine optimum configuration and optimum design conditions for any cycle arrangement. Actually the performance parameters of these cycles are under the influence of various parameters and therefore the recognition of the optimum conditions is quiet complicated. In this research an extensive thermodynamic model was developed for analyzing major parameters variations on gas turbine performance and different configurations of advanced steam cycles: dual and triple pressure cycles with and without reheating in steam turbine sections. In this model it is attempted to consider all factors that affect on actual behavior of these cycles such as blade cooling (air cooling) in gas turbine and different formulations for Heat Recovery Steam Generator (HRSG) performance calculation. Results show good agreement with manufactures data. In the case of gas turbine cycle, location of coolant extraction has large influence on cycle performance. For extraction from compressor end, improving blade cooling technology is suitable than increasing TIT. For mid stage extraction, improving blade cooling technology and TIT has similar effects on efficiency, while power is more sensitive to TIT. Coolant air precooling has large positive effect in high TIT and medium blade cooling technology, but always it increases power. Turbine exhaust temperature has large influence on optimum layout and configuration of HRSG, while for low exhaust temperatures increasing number of pressure levels increase power and heat recovery greatly, for high exhaust temperatures this leads lower enhancement in power and recovery. Second law efficiency of HRSG is proportional to power production in steam cycle. It decreases with increasing gas turbine exhaust temperature.

Internal Reforming Solid Oxide Fuel Cell Gas Turbine Combined Cycles (IRSOFC-GT): Part B — Exergy and Thermoeconomic Analyses

2001 ◽  
Author(s):  
Aristide F. Massardo ◽  
Loredana Magistri
Keyword(s):  
Fuel Cell ◽  
Solid Oxide Fuel Cell ◽  
Gas Turbine ◽  
Operating Conditions ◽  
Solid Oxide ◽  
Specific Work ◽  
Oxide Fuel ◽  
Internal Reforming ◽  
System Pressure ◽  
Combined Cycles

The aim of this work is to investigate the performance of Internal Reforming Solid Oxide Fuel Cell (IRSOFC) and Gas Turbine (GT) combined cycles. A mathematical model of the IRSOFC steady-state operation was presented in Part A of this work (Massardo and Lubelli, 1998), coupled to the thermodynamic analysis of a number of proposed IRSOFC-GT combined cycles, taking into account the influence of several technological constraints. In the second part of this work, both an exergy and a thermoeconomic analysis of the proposed cycles have been carried out using the TEMP code developed by the Author (Agazzani and Massardo, 1997). A suitable equation for IRSOFC cost evaluation based on cell geometry and performance has been proposed and employed to evaluate the electricity generation cost of the proposed combined systems. The results are presented and the influence of several parameters is discussed: external reformer operating conditions, fuel to air ratio, cell current density, compressor pressure ratio, etc. Diagrams proposed by the Author (Massardo and Scialo’, 2000) for cost vs. efficiency, cost vs. specific work, and cost vs. system pressure are also presented and discussed.

System Evaluation and LBTU Fuel Combustion Studies for IGCC Power Generation

1995 ◽  
Vol 117 (4) ◽  
pp. 673-677 ◽  
Author(s):  
C. S. Cook ◽  
J. C. Corman ◽  
D. M. Todd
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Coal Gasification ◽  
Flame Temperature ◽  
Combined Cycle ◽  
Gas Turbine Combustor ◽  
Gas Cleaning ◽  
Wide Range ◽  
Cycle Systems ◽  
Combined Cycles

The integration of gas turbines and combined cycle systems with advances in coal gasification and gas stream cleanup systems will result in economically viable IGCC systems. Optimization of IGCC systems for both emission levels and cost of electricity is critical to achieving this goal. A technical issue is the ability to use a wide range of coal and petroleum-based fuel gases in conventional gas turbine combustor hardware. In order to characterize the acceptability of these syngases for gas turbines, combustion studies were conducted with simulated coal gases using full-scale advanced gas turbine (7F) combustor components. It was found that NOx emissions could be correlated as a simple function of stoichiometric flame temperature for a wide range of heating values while CO emissions were shown to depend primarily on the H2 content of the fuel below heating values of 130 Btu/scf (5125 kJ/NM3) and for H2/CO ratios less than unity. The test program further demonstrated the capability of advanced can-annular combustion systems to burn fuels from air-blown gasifiers with fuel lower heating values as low as 90 Btu/scf (3548 kJ/NM3) at 2300°F (1260°C) firing temperature. In support of ongoing economic studies, numerous IGCC system evaluations have been conducted incorporating a majority of the commercial or near-commercial coal gasification systems coupled with “F” series gas turbine combined cycles. Both oxygen and air-blown configurations have been studied, in some cases with high and low-temperature gas cleaning systems. It has been shown that system studies must start with the characteristics and limitations of the gas turbine if output and operating economics are to be optimized throughout the range of ambient operating temperature and load variation.

On Thermodynamics of Gas-Turbine Cycles: Part 3—Thermodynamic Potential and Limitations of Cooled Reheat-Gas-Turbine Combined Cycles

1986 ◽  
Vol 108 (1) ◽  
pp. 160-168 ◽  
Author(s):  
M. A. El-Masri
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Closed Loop ◽  
Elevated Temperatures ◽  
Pressure Ratio ◽  
Air Cooling ◽  
Full Potential ◽  
Evaporative Water ◽  
Combined Cycles ◽  
Cooling Technology

Reheat gas turbines have fundamental thermodynamic advantages in combined cycles. However, a larger proportion of the turbine expansion path is exposed to elevated temperatures, leading to increased cooling losses. Identifying cooling technologies which minimize those losses is crucial to realizing the full potential of reheat cycles. The strong role played by cooling losses in reheat cycles necessitates their inclusion in cycle optimization. To this end, the models for the thermodynamics of combined cycles and cooled turbines presented in Parts 1 and 2 of this paper have been extended where needed and applied to the analysis of a wide variety of cycles. The cooling methods considered range from established air-cooling technology to methods under current research and development such as air-transpiration, open-loop, and closed-loop water cooling. Two schemes thought worthy of longer-term consideration are also assessed. These are two-phase transpiration cooling and the regenerative thermosyphon. A variety of configurations are examined, ranging from Brayton-cycles to one or two-turbine reheats, with or without compressor intercooling. Both surface intercoolers and evaporative water-spray types are considered. The most attractive cycle configurations as well as the optimum pressure ratio and peak temperature are found to vary significantly with types of cooling technology. Based upon the results of the model, it appears that internal closed-loop liquid cooling offers the greatest potential for midterm development. Hybrid systems with internally liquid-cooled nozzles and traditional air-cooled rotors seem most attractive for the near term. These could be further improved by using steam rather than air for cooling the rotor.

Internal Reforming Solid Oxide Fuel Cell Gas Turbine Combined Cycles (IRSOFC-GT)—Part II: Exergy and Thermoeconomic Analyses

2002 ◽  
Vol 125 (1) ◽  
pp. 67-74 ◽  
Author(s):  
A. F. Massardo
Keyword(s):  
Fuel Cell ◽  
Solid Oxide Fuel Cell ◽  
Gas Turbine ◽  
Operating Conditions ◽  
Solid Oxide ◽  
Specific Work ◽  
Oxide Fuel ◽  
Internal Reforming ◽  
System Pressure ◽  
Combined Cycles

The aim of this work is to investigate the performance of internal reforming solid oxide fuel cell (IRSOFC) and gas turbine (GT) combined cycles. A mathematical model of the IRSOFC steady-state operation was presented in Part I of this work coupled to the thermodynamic analysis of a number of proposed IRSOFC-GT combined cycles, taking into account the influence of several technological constraints. In the second part of this work, both an exergy and a thermoeconomic analysis of the proposed cycles have been carried out using the TEMP code developed by the author. A suitable equation for IRSOFC cost evaluation based on cell geometry and performance has been proposed and employed to evaluate the electricity generation cost of the proposed combined systems. The results are presented and the influence of several parameters is discussed: external reformer operating conditions, fuel-to-air ratio, cell current density, compressor pressure ratio, etc. Diagrams proposed by the author for cost versus efficiency, cost versus specific work, and cost versus system pressure are also presented and discussed.

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