scholarly journals Exergoeconomic and Environmental Analysis and Multi-Objective Optimization of a New Regenerative Gas Turbine Combined Cycle

2021 ◽  
Vol 11 (23) ◽  
pp. 11554
Author(s):  
Ali Baghernejad ◽  
Amjad Anvari-Moghaddam
Keyword(s):  
Gas Turbine ◽  
Pressure Ratio ◽  
Unit Cost ◽  
Environmental Parameters ◽  
Rankine Cycle ◽  
Exergy Efficiency ◽  
Combined Cycle ◽  
Inlet Temperature ◽  
Cost Rate ◽  
Cycle Systems

Combined cycle systems have an important role in power generation. In the present study, three different configurations of combined Brayton and Rankine cycle system are studied from the perspective of energy, exergy, exergoeconomic and environmental perspectives. Results indicate that it depends on the preferences and criteria of each decision maker to select the best configuration among the three proposed configurations as the final configuration. For the purpose of parametric analysis, the effect of changing various parameters such as compressor pressure ratio, gas turbine inlet temperature on the output work, exergy efficiency, exergy-economic and environmental parameters is studied. In addition, an attempt is made to optimize the performance of combined cycle systems considering three objective functions of exergy efficiency, total cost rate and exergy unit cost of produced electricity.

scholarly journals Exergoeconomic and Environmental Modeling of Integrated Polygeneration Power Plant with Biomass-Based Syngas Supplemental Firing

Energies ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 6018
Author(s):  
Fidelis. I. Abam ◽  
Ogheneruona E. Diemuodeke ◽  
Ekwe. B. Ekwe ◽  
Mohammed Alghassab ◽  
Olusegun D. Samuel ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Unit Cost ◽  
Organic Rankine Cycle ◽  
Energy Transition ◽  
Rankine Cycle ◽  
Power Production ◽  
Environmental Modeling ◽  
Exergy Efficiency ◽  
Optimum Operating ◽  
Cost Rate

There is a burden of adequate energy supply for meeting demand and reducing emission to avoid the average global temperature of above 2 °C of the pre-industrial era. Therefore, this study presents the exergoeconomic and environmental analysis of a proposed integrated multi-generation plant (IMP), with supplemental biomass-based syngas firing. An in-service gas turbine plant, fired by natural gas, was retrofitted with a gas turbine (GT), steam turbine (ST), organic Rankine cycle (ORC) for cooling and power production, a modified Kalina cycle (KC) for power production and cooling, and a vapour absorption system (VAB) for cooling. The overall network, energy efficiency, and exergy efficiency of the IMP were estimated at 183 MW, 61.50% and 44.22%, respectively. The specific emissions were estimated at 122.2, 0.222, and 3.0 × 10−7 kg/MWh for CO2, NOx, and CO, respectively. Similarly, the harmful fuel emission factor, and newly introduced sustainability indicators—exergo-thermal index (ETI) and exergetic utility exponent (EUE)—were obtained as 0.00067, 0.675, and 0.734, respectively. The LCC of $1.58 million was obtained, with a payback of 4 years, while the unit cost of energy was estimated at 0.0166 $/kWh. The exergoeconomic factor and the relative cost difference of the IMP were obtained as 50.37% and 162.38%, respectively. The optimum operating parameters obtained by a genetic algorithm gave the plant’s total cost rate of 125.83 $/hr and exergy efficiency of 39.50%. The proposed system had the potential to drive the current energy transition crisis caused by the COVID-19 pandemic shock in the energy sector.

Enhancing Energy and Economic Performances of Combined Cycle Power Plants by Means of Gas-Cycle Regeneration

2014 ◽  
Author(s):  
Roberto Carapellucci ◽  
Lorena Giordano
Keyword(s):  
Gas Turbine ◽  
Power Plants ◽  
Waste Heat ◽  
Pressure Ratio ◽  
Unit Cost ◽  
Combined Cycle ◽  
Operating Conditions ◽  
Inlet Temperature ◽  
Efficiency Gain ◽  
Gas Power Plant

Efficiency improvement in the gas turbine sector has been mainly driven by increasing the turbine inlet temperature and compressor pressure ratio. For a fixed technology level, a further efficiency gain can be achieved through the utilization of waste thermal energy. Regeneration is an internal recovery technique that allows the reduction of heat input required at combustor, by preheating the air at compressor outlet. Under certain operating conditions, the temperature of exhaust gas leaving the regenerator is still enough high to allow the steam production via an heat recovery steam generator (HRSG). Regeneration in steam-gas power plants (CCGT) has the potential to enhance thermal efficiency, but reduces the margins for external recovery and then the bottoming steam cycle capacity. Moreover, the reduction of exhausts temperature at gas turbine outlet requires the reconsideration of HRSG operating parameters, in order to limit the increase of waste heat at the stack. The aim of this study is to explore the potential benefits that regeneration in the gas cycle gives on the whole steam-gas power plant. The extent of energy and economic performances improvement is evaluated, varying the gas turbine specifications and the layout and operating conditions of HRSG. Hence simple and regenerative configurations based on single and multi-pressure HRSG are compared, focusing on efficiency, specific CO2 emissions and unit cost of electricity (COE).

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).

Effect of Deaerator Parameters on Simple and Reheat Gas/Steam Combined Cycle With Different Cooling Medium

2019 ◽  
Author(s):  
Mayank Maheshwari ◽  
Onkar Singh
Keyword(s):  
Gas Turbine ◽  
Mass Fraction ◽  
Power Plants ◽  
Performance Enhancement ◽  
Pressure Ratio ◽  
Combined Cycle ◽  
Cycle Performance ◽  
Inlet Temperature ◽  
Operating Pressure ◽  
Cooling Medium

Abstract Performance of gas/steam combined cycle power plants relies upon the performance exhibited by both gas based topping cycle and steam based bottoming cycle. Therefore, the measures for improving the performance of the gas turbine cycle and steam bottoming cycle eventually result in overall combined cycle performance enhancement. Gas turbine cooling medium affects the cooling efficacy. Amongst different parameters in the steam bottoming cycle, the deaerator parameter also plays its role in cycle performance. The present study analyzes the effect of deaerator’s operating pressure being varied from 1.6 bar to 2.2 bar in different configurations of simple and reheat gas/steam combined cycle with different cooling medium for fixed cycle pressure ratio of 40, turbine inlet temperature of 2000 K and ambient temperature of 303 K with varying ammonia mass fraction from 0.6 to 0.9. Analysis of the results obtained for different combined cycle configuration shows that for the simple gas turbine and reheat gas turbine-based configurations, the maximum work output of 643.78 kJ/kg of air and 730.87 kJ/kg of air respectively for ammonia mass fraction of 0.6, cycle efficiency of 54.55% and 53.14% respectively at ammonia mass fraction of 0.7 and second law efficiency of 59.71% and 57.95% respectively at ammonia mass fraction of 0.7 is obtained for the configuration having triple pressure HRVG with ammonia-water turbine at high pressure and intermediate pressure and steam turbine operating at deaerator pressure of 1.6 bar.

scholarly journals Thermodynamic Investigation of an Integrated Solar Combined Cycle with an ORC System

Entropy ◽  
2019 ◽  
Vol 21 (4) ◽  
pp. 428 ◽  
Author(s):  
Wang ◽  
Fu
Keyword(s):  
Solar Radiation ◽  
Thermal Efficiency ◽  
Unit Cost ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Exergy Efficiency ◽  
Combined Cycle ◽  
Exhaust Gas ◽  
Gas Temperature ◽  
Exhaust Gas Temperature

An integrated solar combined cycle (ISCC) with a low temperature waste heat recovery system is proposed in this paper. The combined system consists of a conventional natural gas combined cycle, organic Rankine cycle and solar fields. The performance of an organic Rankine cycle subsystem as well as the overall proposed ISCC system are analyzed using organic working fluids. Besides, parameters including the pump discharge pressure, exhaust gas temperature, thermal and exergy efficiencies, unit cost of exergy for product and annual CO2-savings were considered. Results indicate that Rc318 contributes the highest exhaust gas temperature of 71.2℃, while R113 showed the lowest exhaust gas temperature of 65.89 at 800 W/m2, in the proposed ISCC system. The overall plant thermal efficiency increases rapidly with solar radiation, while the exergy efficiency appears to have a downward trend. R227ea had both the largest thermal efficiency of 58.33% and exergy efficiency of 48.09% at 800W/m2. In addition, for the organic Rankine cycle, the exergy destructions of the evaporator, turbine and condenser decreased with increasing solar radiation. The evaporator contributed the largest exergy destruction followed by the turbine, condenser and pump. Besides, according to the economic analysis, R227ea had the lowest production cost of 19.3 $/GJ.

scholarly journals Performance Analysis With Different Means of Cooling in a Combined Cycle

1995 ◽  
Author(s):  
Onkar Singh ◽  
R. Yadav
Keyword(s):  
Gas Turbine ◽  
Power Plants ◽  
Pressure Ratio ◽  
Combined Cycle ◽  
Inlet Temperature ◽  
Optimum Pressure ◽  
Cooling Medium ◽  
Cooling Technology ◽  
Improved Performance ◽  
Topping Cycle

Combined cycle based power plants and their development and application for energy efficient base load power generation necessitates enforced cooling to maintain the topping cycle gas turbine blade temperature at permissible levels, attributed to the increased turbine inlet temperature and compressor pressure ratio, for the improved performance and reliability of combined cycle. The mathematical model based on expansion path inside gas turbine considering dilution of mainstream and aerodynamic mixing losses for a range of cooling medium has been developed based on internal, film, transpiration cooling technologies and a combination of these. It is found that the appreciation of a cycle configuration as well as the optimum pressure ratio and peak temperature vary significantly with types of cooling technology adopted. Steam cooling for rotor appears to be a very potential cooling medium, when employed with an appropriate cooling technology. This paper deals with the thermodynamic analysis of turbine cooling using, different means of cooling i.e. air, water and steam.

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.

Analysis of Off-Design Behavior of a Solar-Fossil Hybrid Combined Cycle Plant Using a Small Particle Heat Exchange Receiver (SPHER) With a Variable Guide Vane Gas Turbine

2016 ◽  
Author(s):  
Matthew Miguel Virgen ◽  
Fletcher Miller
Keyword(s):  
Heat Exchange ◽  
Gas Turbine ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Small Particle ◽  
Guide Vane ◽  
Rankine Cycle ◽  
Combined Cycle ◽  
Inlet Temperature

Two significant goals in solar plant operation are lower cost and higher efficiencies. This is both for general competitiveness of solar technology in the energy industry, and also to meet the US DOE Sunshot Initiative Concentrating Solar Power (CSP) cost goals [1]. We present here an investigation on the effects of adding a bottoming steam power cycle to a solar-fossil hybrid CSP plant based on a Small Particle Heat Exchange Receiver (SPHER) driving a gas turbine as the primary cycle. Due to the high operating temperature of the SPHER being considered (over 1000 Celsius), the exhaust air from the primary Brayton cycle still contains a tremendous amount of exergy. This exergy of the gas flow can be captured in a heat recovery steam generator (HRSG), to generate superheated steam and run a bottoming Rankine cycle, in a combined cycle gas turbine (CCGT) system. A wide range of cases were run to explore options for maximizing both power and efficiency from the proposed CSP CCGT plant. Due to the generalized nature of the bottoming cycle modeling, and the varying nature of solar power, special consideration had to be given to the behavior of the heat exchanger and Rankine cycle in off-design scenarios. Variable guide vanes (VGVs), which can control the mass flow rate through the gas turbine system, have been found to be an effective tool in providing operational flexibility to address the variable nature of solar input. The effect VGVs and the operating range associated with them are presented. Strategies for meeting a minimum solar share are also explored. Trends with respect to the change in variable guide vane angle are discussed, as well as the response of the HRSG and bottoming Rankine cycle in response to changes in the gas mass flow rate and temperature. System efficiencies in the range of 50% were found to result from this plant configuration. However, a combustor inlet temperature (CIT) limit lower than a turbine inlet temperature (TIT) limit leads two distinct Modes of operation, with a sharp drop in both plant efficiency and power occurring when the air flow through the receiver exceeded the (CIT) limit, and as a result would have to bypass the combustor entirely and enter the turbine at a significantly lower temperature than nominal. Until that limit is completely eliminated through material or design improvements, this drawback can be addressed through strategic use of the variable guide vanes. Optimal operational strategy is ultimately decided by economics, plant objectives, or other market incentives.

Performance Enhancement of Advanced Combined Cycles

2003 ◽  
Author(s):  
Sanjay ◽  
Onkar Singh ◽  
B. N. Prasad
Keyword(s):  
Gas Turbine ◽  
Steam Generator ◽  
Heat Recovery ◽  
Performance Enhancement ◽  
Pressure Ratio ◽  
Combined Cycle ◽  
Inlet Temperature ◽  
Heat Recovery Steam Generator ◽  
Component Efficiency ◽  
Plant Efficiency

This paper reports on the development requirements of gas/steam combined cycle with an aim to achieve plant efficiency greater than 62% through various development possibilities in gas turbine and steam turbine cycle by taking a reference combined cycle configuration (MS9001H gas turbine and three pressure heat recovery steam generator with reheat). The innovative development possibilities include the advanced inlet design to reduce pressure loss, the increase in turbine inlet temperature, use of advanced turbine blade material, increased component efficiency, improved turbine cooling technologies along with better cooling medium, incorporating intercooling, reheat and regeneration either separately or in combination with simple gas turbine cycle using higher compressor pressure ratio, better utilization of heat recovery steam generator, minimum stack temperature, single shaft system configuration, etc. Based on the quantification of each development item, if incorporated in reference cycle, it has been estimated that the combined cycle as the potential to achieve the plant efficiency in excess of 63%.

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