Second Law Analysis of Integrated Solar Combined Cycle Power Plants

2015 ◽  
Vol 137 (5) ◽  
Author(s):  
S. Can Gülen
Keyword(s):  
Power Generation ◽  
Power Plants ◽  
Thermal Power ◽  
Second Law Of Thermodynamics ◽  
Combined Cycle ◽  
Solar Thermal ◽  
Second Law ◽  
Seamless Integration ◽  
Gas Combustion ◽  
Use Of Time

Integrated solar combined cycle (ISCC) is an operationally simple, clean electric power generation system that is economically more attractive vis-à-vis stand-alone concentrating solar power (CSP) technology. The ISCC can be designed to achieve two primary goals: (1) replace natural gas combustion with solar thermal power at the same output rating to reduce fuel consumption and stack emissions and/or (2) replace supplementary (duct) firing in the heat recovery steam generator (HRSG) with “solar firing” to boost power generation on hot days. Optimal ISCC design requires a seamless integration of the solar thermal and fossil-thermal technologies to maximize the solar contribution to the overall system performance at the lowest possible size and cost. The current paper uses the exergy concept of the second law of thermodynamics to distill the quite complex optimization problem to its bare essentials. The goal is to provide the practitioners with physics-based, user-friendly guidelines to understand the key drivers and the interaction among them. Ultimately, such understanding is expected to help direct studies involving heavy use of time consuming system models in a focused manner and evaluate the results critically to arrive at feasible ISCC designs.

Second Law Analysis of Integrated Solar Combined Cycle Power Plants

2014 ◽  
Author(s):  
S. Can Gülen
Keyword(s):  
Power Generation ◽  
Power Plants ◽  
Thermal Power ◽  
Second Law Of Thermodynamics ◽  
Combined Cycle ◽  
Solar Thermal ◽  
Second Law ◽  
Seamless Integration ◽  
Gas Combustion ◽  
Use Of Time

Integrated Solar Combined Cycle (ISCC) is an operationally simple, clean electric power generation system that is economically more attractive vis-à-vis stand-alone Concentrating Solar Power (CSP) technology. The ISCC can be designed to achieve two primary goals: (1) replace natural gas combustion with solar thermal power at the same output rating to reduce fuel consumption and stack emissions and/or (2) replace supplementary (duct) firing in the Heat Recovery Steam Generator (HRSG) with “solar firing” to boost power generation on hot days. Optimal ISCC design requires a seamless integration of the solar-thermal and fossil-thermal technologies to maximize the solar contribution to the overall system performance at the lowest possible size and cost. The current paper uses the exergy concept of the second law of thermodynamics to distill the quite complex optimization problem to its bare essentials. The goal is to provide the practitioners with physics-based, user-friendly guidelines to understand the key drivers and the interaction among them. Ultimately, such understanding is expected to help direct studies involving heavy use of time consuming system models in a focused manner and evaluate the results critically to arrive at feasible ISCC designs.

Parameterization of High Solar Share Gas Turbine Systems

2012 ◽  
Author(s):  
Stephan Heide ◽  
Christian Felsmann ◽  
Uwe Gampe ◽  
Sven Boje ◽  
Bernd Gericke ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Power Plants ◽  
Planning Process ◽  
Pressure Ratio ◽  
Thermal Power ◽  
Combined Cycle ◽  
Process Models ◽  
Solar Thermal ◽  
Thermal Power Plants ◽  
Solar Thermal Power

Existing solar thermal power plants are based on steam turbine cycles. While their process temperature is limited, solar gas turbine (GT) systems provide the opportunity to utilize solar heat at a much higher temperature. Therefore there is potential to improve the efficiency of future solar thermal power plants. Solar based heat input to substitute fuel requires specific GT features. Currently the portfolio of available GTs with these features is restricted. Only small capacity research plants are in service or in planning. Process layout and technology studies for high solar share GT systems have been carried out and have already been reported by the authors. While these investigations are based on a commercial 10MW class GT, this paper addresses the parameterization of high solar share GT systems and is not restricted to any type of commercial GT. Three configurations of solar hybrid GT cycles are analyzed. Besides recuperated and simple GT with bottoming Organic Rankine Cycle (ORC), a conventional combined cycle is considered. The study addresses the GT parameterization. Therefore parametric process models are used for simulation. Maximum electrical efficiency and associated optimum compressor pressure ratio πC are derived at design conditions. The pressure losses of the additional solar components of solar hybrid GTs have a different adversely effect on the investigated systems. Further aspects like high ambient temperature, availability of water and influence of compressor pressure level on component design are discussed as well. The present study is part of the R&D project Hybrid High Solar Share Gas Turbine Systems (HYGATE) which is funded by the German Ministry for the Environment, Nature and Nuclear Safety and the Ministry of Economics and Technology.

Cogenerative Below Ambient Gas Turbine (BAGT) Performance With Variable Thermal Power

2005 ◽  
Vol 127 (3) ◽  
pp. 592-598 ◽  
Author(s):  
M. Bianchi ◽  
G. Negri di Montenegro ◽  
A. Peretto
Keyword(s):  
Power Generation ◽  
Electric Power ◽  
Gas Turbine ◽  
Power Plants ◽  
Ambient Pressure ◽  
Thermal Power ◽  
Combined Cycle ◽  
Electric Power Generation ◽  
Pressure Discharge ◽  
Discharge Gas

The use of gas turbine and combined cycle power plants for thermal and electric power generation is, nowadays, a consolidated technology. Moreover, the employment of combined heat and power production, especially for low power requirements, is constantly increasing. In this scenario, below ambient pressure discharge gas turbine (BAGT) is an innovative and interesting application; the hot gases discharged from a gas turbine may be expanded below ambient pressure to obtain an increase in electric power generation. The gases are then cooled to supply heat to the thermal utility and finally recompressed to the ambient pressure. The power plant cogenerative performance depends on the heat and electric demand that usually varies during the year (for residential heating the heat to electric power ratio may range from 0.3 to 9). In this paper, the thermal load variation influence on the BAGT performance will be investigated and compared with those of gas turbine and combined cycle power plants.

Thermodynamic Analyses of Single Brayton and Combined Brayton–Rankine Cycles for Distributed Solar Thermal Power Generation

2011 ◽  
Author(s):  
Marc Dunham ◽  
Wojciech Lipinski
Keyword(s):  
Heat Transfer ◽  
Carbon Dioxide ◽  
Power Generation ◽  
Thermal Power ◽  
Combined Cycle ◽  
Solar Thermal ◽  
Brayton Cycle ◽  
Solar Thermal Power ◽  
Topping Cycle ◽  
Solar Thermal Power Generation

This paper explores the theoretical efficiencies of single Brayton and combined Brayton-Rankine thermodynamic power cycles for distributed solar thermal power generation. Thermodynamic analyses are conducted for the nominal solar power input to the receiver of 75 kW, concentration ratio in the range 50–100 suns, and for selected heat transfer fluids including air, argon, carbon dioxide, helium, and hydrogen for the Brayton cycle and for the topping cycle of the combined system. C6-fluoroketone, cyclohexane, n-pentane, R-141b, R-245fa, HFE-7000, and steam are examined as working fluids in the bottoming segment of the combined cycle. A single Brayton cycle is found to reach a peak efficiency of 13.3% with carbon dioxide and 100 suns solar input. The four top-performing Brayton cycle fluids are examined as topping cycle fluids in the combined cycle. Each of the four fluids is paired with seven potential bottoming fluids, resulting in 28 heat transfer fluid configurations. The combination of the Brayton topping cycle using carbon dioxide and the Rankine bottoming cycle using R-141b gives the highest thermal efficiency of 22.3% for 100 suns.

Greenhouse Gas Emissions Reduction Potentials in Iranian Electricity Generation Sector and Comparison With Canada

2008 ◽  
Author(s):  
Farshid Zabihian ◽  
Alan S. Fung
Keyword(s):  
Power Generation ◽  
Natural Gas ◽  
Greenhouse Gas ◽  
Electricity Generation ◽  
Power Plants ◽  
Thermal Power ◽  
Ghg Emissions ◽  
Combined Cycle ◽  
Reduction Potentials ◽  
Power Stations

In recent years, greenhouse gas (GHG) emissions and their potential effects on the global climate change have been a worldwide concern. Based on International Energy Agency (IEA), power generation contributes half of the increase in global GHG emissions in 2030. In the Middle East, Power generation is expected to make the largest contribution to the growth in carbon-dioxide emissions. The share of the power sector in the region’s total CO2 emissions will increase from 34% in 2003 to 36% in 2030. Therefore, it is very important to reduce GHG emissions in this industry. The purpose of this paper is to examine greenhouse gas emissions reduction potentials in the Iranian electricity generation sector through fuel switching and adoption of advanced power generation systems and to compare these potentials with Canadian electricity generation sector. These two countries are selected because of raw data availability and their unique characteristics in electricity generation sector. To achieve this purpose two different scenarios have been introduced: Scenario #1: Switching existing power stations fuel to natural gas. Scenario #2: Replacing existing power plants by natural gas combined-cycle (NGCC) power stations (The efficiency of NGCC is considered to be 49%). The results shows that the GHG reduction potential for Iranian steam power plants, gas turbines and combined cycle power plants in first scenario are 9.9%, 5.6%, and 2.6%, respectively with the average of 7.6%. For the second scenario the overall reduction of 31.9%, is expected. The average reduction potential for Canadian power plants for scenario number 1 and 2 are 33% and 59%, respectively. As it can be seen, in Canada there are much higher potentials to reduce GHG emissions. The reason is that in Canada majority of power plants use coal as the primary fuel. In fact almost 73% of electricity in thermal power stations is generated by coal. Whereas in Iran almost all power plants (with some exceptions) are dual fuels and 77% of energy consumed in Iran’s thermal power plants come from natural gas. Also, 21% of total electricity generated in Iran is produced by combined-cycle power plants.

COST-EFFECTIVE AND RELIABLE DESIGN OF A SOLAR THERMAL POWER PLANT

2009 ◽  
Vol 33 (1) ◽  
pp. 25-38 ◽  
Author(s):  
A. A. Aliabadi ◽  
J. S. Wallace
Keyword(s):  
Power Generation ◽  
Power Plant ◽  
Power Plants ◽  
Thermal Power ◽  
Thermal Storage ◽  
Mineral Oil ◽  
Solar Thermal ◽  
Heat Transfer Fluid ◽  
Solar Thermal Power ◽  
Evacuated Tube

A design study was conducted to evaluate the cost-effectiveness of solar thermal power generation in a 50 kWe power plant that could be used in a remote location. The system combines a solar collector-thermal storage system utilizing a heat transfer fluid and a simple Rankine cycle power generator utilizing R123 refrigerant. Evacuated tube solar collectors heat mineral oil and supply it to a thermal storage tank. A mineral oil to refrigerant heat exchanger generates superheated refrigerant vapor, which drives a radial turbogenerator. Supplemental natural gas firing maintains a constant thermal storage temperature irregardless of solar conditions enabling the system to produce a constant 50 kWe output. A simulation was carried out to predict the performance of the system in the hottest summer day and the coldest winter day for southern California solar conditions. A rigorous economic analysis was conducted. The system offers advantages over advanced solar thermal power plants by implementing simple fixed evacuated tube collectors, which are less prone to damage in harsh desert environment. Also, backed up by fossil fuel power generation, it is possible to obtain continued operation even during low insolation sky conditions and at night, a feature that stand-alone PV systems do not offer.

scholarly journals Statistical Analysis for Parametric Optimization of Gas Turbine-Steam Turbine Combined Power Cycle with Different Natural Gas Combustion

2019 ◽  
Vol 8 (4) ◽  
pp. 4563-4570
Keyword(s):  
Power Generation ◽  
Combustion Chamber ◽  
Steam Turbine ◽  
Gas Turbine ◽  
Compression Ratio ◽  
Power Plants ◽  
Parametric Optimization ◽  
Pressure Ratio ◽  
Thermal Power ◽  
Gas Combustion

The combined Gas Turbine (GT) and Steam Turbine (ST) power generation techniques plays important role in power production. The coal fired thermal power plants have maximum possible efficiency about 34-36% with all arrangements of reheating and regeneration thermal systems. The integration of GT power generation system with old coal based thermal power plant helps to re-powering of plant and utilization of exhaust energy of GT unit through heat recovery steam generator (HRSG) of ST plant. The proposed title of research deals two steps of analysis. Energy analysis is adopted as first step for performance and energy destruction evaluation purpose where as Multi Linear regression (MLR) method is introduced as second method for parametric optimization. The four natural gases have been considered in this analysis and investigate the suitable fuel gas performance as per operating condition of GT plant such as gas turbine inlet turbine temperature (GTIT), compression ratio (CR) and mass flow of gases. The result of this paper concluded as maximum exergy loss found in combustion chamber of GT system and exhaust flow system of ST system in terms of 41% and 8% respectively. The combined and exergetic efficiency of plant are estimated to be 41% and 38.5% respectively. In present statistical model 4 levels and 3 factors (Pressure ratio, operating temperature and type of fuel gases) have been considered. And overall efficiency, gas turbine efficiency, heat loss in GT plant, Exergy destruction in thermal utilities like Compressor, combustion chamber and gas turbine are investigated. The statistical modeling concluded that the comparative results of actual and predicted results at different compression ratio of combustible gases which is affects the overall performance of combined GT-ST plant. This study helps to justify possible efficiency improvement with identifying the irreversibilities of plant utilities.

Cogenerative BAGT Performance With Variable Thermal Power

2002 ◽  
Author(s):  
M. Bianchi ◽  
G. Negri di Montenegro ◽  
A. Peretto
Keyword(s):  
Power Generation ◽  
Electric Power ◽  
Gas Turbine ◽  
Power Plants ◽  
Ambient Pressure ◽  
Thermal Power ◽  
Combined Cycle ◽  
Electric Power Generation ◽  
Pressure Discharge ◽  
Discharge Gas

The use of gas turbine and combined cycle power plants for thermal and electric power generation is, nowadays, a consolidated technology. Moreover the employment of combined heat and power production, especially for low power requirements, is constantly increasing. In this scenario, Below Ambient pressure discharge Gas Turbine (BAGT) is an innovative and interesting application; the hot gases discharged from a gas turbine may be expanded below ambient pressure to obtain an increase in electric power generation. The gases are then cooled to supply heat to the thermal utility and finally recompressed to the ambient pressure. The power plant cogenerative performance depends on the heat and electric demand that usually varies during the year (for residential heating the heat to electric power ratio may range from 0.3 to 9). In this paper, the thermal load variation influence on the BAGT performance will be investigated and compared with those of gas turbine and combined cycle power plants.

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