The Experts below are selected from a list of 15447 Experts worldwide ranked by ideXlab platform
Afzal S Siddiqui - One of the best experts on this subject based on the ideXlab platform.
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valuing a gas Fired Power Plant a comparison of ordinary linear models regime switching approaches and models with stochastic volatility
Energy Economics, 2010Co-Authors: Somayeh Heydari, Afzal S SiddiquiAbstract:Energy prices are often highly volatile with unexpected spikes. Capturing these sudden spikes may lead to more informed decision-making in energy investments, such as valuing gas-Fired Power Plants, than ignoring them. In this paper, non-linear regime-switching models and models with mean-reverting stochastic volatility are compared with ordinary linear models. The study is performed using UK electricity and natural gas daily spot prices and suggests that with the aim of valuing a gas-Fired Power Plant with and without operational flexibility, non-linear models with stochastic volatility, specifically for logarithms of electricity prices, provide better out-of-sample forecasts than both linear models and regime-switching models.
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valuing a gas Fired Power Plant a comparison of ordinary linear models regime switching approaches and models with stochastic volatility
Energy Economics, 2010Co-Authors: Somayeh Heydari, Afzal S SiddiquiAbstract:Energy prices are often highly volatile with unexpected spikes. Capturing these sudden spikes may lead to more informed decision-making in energy investments, such as valuing gas-Fired Power Plants, than ignoring them. In this paper, non-linear regime-switching models and models with mean-reverting stochastic volatility are compared with ordinary linear models. The study is performed using UK electricity and natural gas daily spot prices and suggests that with the aim of valuing a gas-Fired Power Plant with and without operational flexibility, non-linear models with stochastic volatility, specifically for logarithms of electricity prices, provide better out-of-sample forecasts than both linear models and regime-switching models.
Jinliang Xu - One of the best experts on this subject based on the ideXlab platform.
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connected top bottom cycle to cascade utilize flue gas heat for supercritical carbon dioxide coal Fired Power Plant
Energy Conversion and Management, 2018Co-Authors: Jinliang Xu, Mingjia LiAbstract:Abstract For coal Fired Power Plant, the supercritical carbon dioxide Brayton cycle (S-CO2) is difficult to absorb flue gas heat in a wide temperature range of 120–1500 °C. Here, novel methods are developed to cascade utilize flue gas heat, in which energies in high, moderate and low temperature levels are extracted by top cycle, bottom cycle or flue gas cooler (FGC), and air preheater, respectively. The cascade utilization shall satisfy the criterion that CO2 temperature entering boiler for top cycle equals to CO2 temperature leaving boiler for bottom cycle. The separate-top-bottom-cycle (STB) is proposed, in which no any component is shared by top and bottom cycles. Six possible bottom cycles are studied. The thermodynamics analysis is coupled with heat transfer and pressure drop analysis for whole Power Plant. It is found that the main vapor pressure of bottom cycle can be the “best” parameter to be adjusted over a wide range of 15–35 MPa to couple and optimize top and bottom cycles. Then, the parameter coordination principle is proposed to share specific components for top and bottom cycles. Thus, the separate cycles are converted into a connected cycle to simplify the whole system layout. The connected cycle has a Power generation efficiency of 51.82% at main vapor parameters of 700 °C/35 MPa, significantly higher than available supercritical water-steam Rankine cycle Power Plant. The findings in this paper give a clue to further raise the Power generation efficiency for large scale S-CO2 coal Fired Power Plant.
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key issues and solution strategies for supercritical carbon dioxide coal Fired Power Plant
Energy, 2018Co-Authors: Jinliang Xu, Mingjia LiAbstract:Abstract When supercritical carbon dioxide (S CO2) Brayton cycle is used for coal Fired Power Plant, the significantly increased flow rate causes extremely large boiler pressure drops, and residual flue gas energy extraction becomes difficult. This paper contains two consecutive parts to resolve these issues. The first part deals with general analysis. Results show that, introducing intercooling and/or reheating into cycle apparently elevate thermal efficiencies, but cycle performance is obviously deteriorated by large pressure drops. Partial flow strategy was proposed in part 2 to yield boiler module design. Both flow rate and length for each module are cut to be half, reducing pressure drop to 1/8 of that with total flow mode. Surprisingly, we show that CO2 boiler pressure drop can be equivalent to or even smaller than that for supercritical water-steam boiler. Three flue gas energy extraction schemes are proposed. The case A scheme not only keeps lower exit flue gas temperature (∼120 °C), but also maintains acceptable secondary air temperature. Finally, a 1000 MWe S CO2 Power Plant design is given. With main vapor parameters 620 °C/30 MPa, thermal efficiency and Power efficiency are 51.22% and 48.37% respectively, showing advantages over supercritical water-steam Rankine cycle. Future works are recommended on S CO2 Power Plant design.
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technical and economical optimization for a typical solar hybrid coal Fired Power Plant in china
Applied Thermal Engineering, 2017Co-Authors: Yanjuan Wang, Jinliang Xu, Zhewen Chen, Hui Cao, Bo ZhangAbstract:Abstract Solar hybrid coal-Fired Power Plant can use solar heat with temperature lower than 300 °C to generate Power efficiently by replacing the bled-off steam from a steam turbine to heat the feed water. In this paper, a model of the solar field and Power block has been developed to investigate the thermodynamic and economic performances of a solar hybrid coal-Fired Power Plant under a variety of operating conditions and structure layouts. The effects of the key operating parameters on the performances of the solar hybrid coal-Fired Power Plant are numerically investigated. A technical and economical optimization of the solar multiple has been presented. Furthermore, the annual solar-to-electric efficiency, annual solar Power output and levelized cost of electricity of the solar hybrid coal-Fired Power Plant are also analyzed. It is found that the efficiencies in the region of 13–20% can be achieved, and this for levelized cost of electricity in the region of 0.7–1.1 ¥ /kW h e , depending on the solar multiple and substituting method.
Hongguang Jin - One of the best experts on this subject based on the ideXlab platform.
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performance assessment of hybrid solar energy and coal Fired Power Plant based on feed water preheating
Energy, 2017Co-Authors: Hui Hong, Shuo Peng, Hao Zhang, Jie Sun, Hongguang JinAbstract:Abstract Hybridizing solar energy and coal-Fired steam Power Plant is one of most attractive approaches of cost-efficient solar electricity in the present. By using the concentrated solar heat at around 300 °C to replace the bleed steam of the turbine for preheating feed-water of coal-Fired steam cycle, higher solar-to-Power efficiency is possibly achieved in that the conversion of solar to Power can utilize higher-temperature steam cycle. In this paper, with the aid of exergy methodology, we derive expressions of the conversion of solar energy into Power for such kind of solar hybrid Plant, especially an explicit correlation is obtained for explaining solar-to-Power efficiency. By using the derived expressions, we examine a typical hybrid solar system with 330 MW coal-Fired Power Plant and evaluate thermal performance of solar-to-Power. In addition, the influences of key operation parameters on the solar thermal performance are disclosed such as solar irradiation, incident angle and turbine load. The results obtained here would be expected to provide a possibility for designing and evaluating practical hybrid solar and coal-Fired Power Plant.
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off design thermodynamic performances on typical days of a 330mw solar aided coal Fired Power Plant in china
Applied Energy, 2014Co-Authors: Shuo Peng, Hui Hong, Yanjuan Wang, Zhaoguo Wang, Hongguang JinAbstract:The contribution of mid-temperature solar thermal Power to improve the performance of coal-Fired Power Plant is analyzed in the present paper. In the solar aided coal-Fired Power Plant, solar heat at<300°C is used to replace the extracted steam from the steam turbine to heat the feed water. In this way, the steam that was to be extracted could consequently expand in the steam turbine to boost output Power. The advantages of a solar aided coal-Fired Power Plant in design condition have been discussed by several researchers. However, thermodynamic performances on off-design operation have not been well discussed until now. In this paper, a typical 330MW coal-Fired Power Plant in Sinkiang Province of China is selected as the case study to demonstrate the advantages of the solar aided coal-Fired Power Plant under off-design conditions. Hourly thermodynamic performances are analyzed on typical days under partial load. The effects of several operational parameters, such as solar irradiation intensity, incident angle, flow rate of thermal oil, on the performance of solar field efficiency and net solar-to-electricity efficiency were examined. Possible schemes have been proposed for improving the solar aided coal-Fired Power Plant on off-design operation. The results obtained in the current study could provide a promising approach to solve the poor thermodynamic performance of solar thermal Power Plant and also offer a basis for the practical operation of MW-scale solar aided coal-Fired Power Plant.
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exergy evaluation of a typical 330 mw solar hybrid coal Fired Power Plant in china
Energy Conversion and Management, 2014Co-Authors: Shuo Peng, Hui Hong, Zhaoguo Wang, Da Xu, Hongguang JinAbstract:Abstract This study discusses the thermodynamic performance of a solar-hybrid coal-Fired Power Plant that uses solar heat with temperature lower than 300 °C to replace the extracted steam from a steam turbine to heat the feed water. Through this process, the steam that was to be extracted can efficiently expand in the steam turbine to generate electricity. The flow rate of steam returning to the turbine retains only a small part of the main stream, allowing the steam turbine to run close to design conditions for all DNI. A solar-only thermal Power Plant without storage is also discussed to illustrate the advantages of a solar-hybrid coal-Fired Power Plant. The off-design performances of both Plants are compared based on the energy-utilization diagram method. The exergy destruction of the solar-hybrid coal-Fired Power Plant is found to be lower than that of the solar-only thermal Power Plant. The comparison of two Plants, which may provide detailed information on internal phenomena, highlights several advantages of the solar-hybrid coal-Fired Power Plant in terms of off-design operation: lower exergy destruction in the solar feed water heater and steam turbine and higher exergy and solar-to-electricity efficiency. Preliminary technological economic performances of both Plants are compared. The results obtained in this study indicate that a solar-hybrid coal-Fired Power Plant could achieve better off-design performance and economic performance than a solar-only thermal Power Plant.
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proposed partial rePowering of a coal Fired Power Plant using low grade solar thermal energy
International Journal of Thermodynamics, 2011Co-Authors: Hui Hong, Yawen Zhao, Hongguang JinAbstract:In this paper, a hybrid Power-generation system with integration of solar heat at approximately 300 ⁰C was proposed for a coal-Fired Power Plant. The system was investigated with the aid of energy-utilization diagram methodology (EUD methodology). In this research, instead of steam, low-grade solar heat was utilized to heat the feed water, leading to an improvement in the Plant thermodynamic performance. The net annual solar-to-electric efficiency was recorded as over 15%. Solar feed-water heaters can operate in line with previously used feed-water heaters during the solar off-design period. A preliminary economic evaluation demonstrated that the increased capital cost of the solar collectors may be approximately $2,007/kWe. The promising results indicated that the proposed thermal cycle offers an approach that integrates mid-temperature solar heat to partially rePower existing coal-Fired Power Plants.
Mingjia Li - One of the best experts on this subject based on the ideXlab platform.
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connected top bottom cycle to cascade utilize flue gas heat for supercritical carbon dioxide coal Fired Power Plant
Energy Conversion and Management, 2018Co-Authors: Jinliang Xu, Mingjia LiAbstract:Abstract For coal Fired Power Plant, the supercritical carbon dioxide Brayton cycle (S-CO2) is difficult to absorb flue gas heat in a wide temperature range of 120–1500 °C. Here, novel methods are developed to cascade utilize flue gas heat, in which energies in high, moderate and low temperature levels are extracted by top cycle, bottom cycle or flue gas cooler (FGC), and air preheater, respectively. The cascade utilization shall satisfy the criterion that CO2 temperature entering boiler for top cycle equals to CO2 temperature leaving boiler for bottom cycle. The separate-top-bottom-cycle (STB) is proposed, in which no any component is shared by top and bottom cycles. Six possible bottom cycles are studied. The thermodynamics analysis is coupled with heat transfer and pressure drop analysis for whole Power Plant. It is found that the main vapor pressure of bottom cycle can be the “best” parameter to be adjusted over a wide range of 15–35 MPa to couple and optimize top and bottom cycles. Then, the parameter coordination principle is proposed to share specific components for top and bottom cycles. Thus, the separate cycles are converted into a connected cycle to simplify the whole system layout. The connected cycle has a Power generation efficiency of 51.82% at main vapor parameters of 700 °C/35 MPa, significantly higher than available supercritical water-steam Rankine cycle Power Plant. The findings in this paper give a clue to further raise the Power generation efficiency for large scale S-CO2 coal Fired Power Plant.
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key issues and solution strategies for supercritical carbon dioxide coal Fired Power Plant
Energy, 2018Co-Authors: Jinliang Xu, Mingjia LiAbstract:Abstract When supercritical carbon dioxide (S CO2) Brayton cycle is used for coal Fired Power Plant, the significantly increased flow rate causes extremely large boiler pressure drops, and residual flue gas energy extraction becomes difficult. This paper contains two consecutive parts to resolve these issues. The first part deals with general analysis. Results show that, introducing intercooling and/or reheating into cycle apparently elevate thermal efficiencies, but cycle performance is obviously deteriorated by large pressure drops. Partial flow strategy was proposed in part 2 to yield boiler module design. Both flow rate and length for each module are cut to be half, reducing pressure drop to 1/8 of that with total flow mode. Surprisingly, we show that CO2 boiler pressure drop can be equivalent to or even smaller than that for supercritical water-steam boiler. Three flue gas energy extraction schemes are proposed. The case A scheme not only keeps lower exit flue gas temperature (∼120 °C), but also maintains acceptable secondary air temperature. Finally, a 1000 MWe S CO2 Power Plant design is given. With main vapor parameters 620 °C/30 MPa, thermal efficiency and Power efficiency are 51.22% and 48.37% respectively, showing advantages over supercritical water-steam Rankine cycle. Future works are recommended on S CO2 Power Plant design.
Hui Hong - One of the best experts on this subject based on the ideXlab platform.
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performance assessment of hybrid solar energy and coal Fired Power Plant based on feed water preheating
Energy, 2017Co-Authors: Hui Hong, Shuo Peng, Hao Zhang, Jie Sun, Hongguang JinAbstract:Abstract Hybridizing solar energy and coal-Fired steam Power Plant is one of most attractive approaches of cost-efficient solar electricity in the present. By using the concentrated solar heat at around 300 °C to replace the bleed steam of the turbine for preheating feed-water of coal-Fired steam cycle, higher solar-to-Power efficiency is possibly achieved in that the conversion of solar to Power can utilize higher-temperature steam cycle. In this paper, with the aid of exergy methodology, we derive expressions of the conversion of solar energy into Power for such kind of solar hybrid Plant, especially an explicit correlation is obtained for explaining solar-to-Power efficiency. By using the derived expressions, we examine a typical hybrid solar system with 330 MW coal-Fired Power Plant and evaluate thermal performance of solar-to-Power. In addition, the influences of key operation parameters on the solar thermal performance are disclosed such as solar irradiation, incident angle and turbine load. The results obtained here would be expected to provide a possibility for designing and evaluating practical hybrid solar and coal-Fired Power Plant.
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off design thermodynamic performances on typical days of a 330mw solar aided coal Fired Power Plant in china
Applied Energy, 2014Co-Authors: Shuo Peng, Hui Hong, Yanjuan Wang, Zhaoguo Wang, Hongguang JinAbstract:The contribution of mid-temperature solar thermal Power to improve the performance of coal-Fired Power Plant is analyzed in the present paper. In the solar aided coal-Fired Power Plant, solar heat at<300°C is used to replace the extracted steam from the steam turbine to heat the feed water. In this way, the steam that was to be extracted could consequently expand in the steam turbine to boost output Power. The advantages of a solar aided coal-Fired Power Plant in design condition have been discussed by several researchers. However, thermodynamic performances on off-design operation have not been well discussed until now. In this paper, a typical 330MW coal-Fired Power Plant in Sinkiang Province of China is selected as the case study to demonstrate the advantages of the solar aided coal-Fired Power Plant under off-design conditions. Hourly thermodynamic performances are analyzed on typical days under partial load. The effects of several operational parameters, such as solar irradiation intensity, incident angle, flow rate of thermal oil, on the performance of solar field efficiency and net solar-to-electricity efficiency were examined. Possible schemes have been proposed for improving the solar aided coal-Fired Power Plant on off-design operation. The results obtained in the current study could provide a promising approach to solve the poor thermodynamic performance of solar thermal Power Plant and also offer a basis for the practical operation of MW-scale solar aided coal-Fired Power Plant.
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exergy evaluation of a typical 330 mw solar hybrid coal Fired Power Plant in china
Energy Conversion and Management, 2014Co-Authors: Shuo Peng, Hui Hong, Zhaoguo Wang, Da Xu, Hongguang JinAbstract:Abstract This study discusses the thermodynamic performance of a solar-hybrid coal-Fired Power Plant that uses solar heat with temperature lower than 300 °C to replace the extracted steam from a steam turbine to heat the feed water. Through this process, the steam that was to be extracted can efficiently expand in the steam turbine to generate electricity. The flow rate of steam returning to the turbine retains only a small part of the main stream, allowing the steam turbine to run close to design conditions for all DNI. A solar-only thermal Power Plant without storage is also discussed to illustrate the advantages of a solar-hybrid coal-Fired Power Plant. The off-design performances of both Plants are compared based on the energy-utilization diagram method. The exergy destruction of the solar-hybrid coal-Fired Power Plant is found to be lower than that of the solar-only thermal Power Plant. The comparison of two Plants, which may provide detailed information on internal phenomena, highlights several advantages of the solar-hybrid coal-Fired Power Plant in terms of off-design operation: lower exergy destruction in the solar feed water heater and steam turbine and higher exergy and solar-to-electricity efficiency. Preliminary technological economic performances of both Plants are compared. The results obtained in this study indicate that a solar-hybrid coal-Fired Power Plant could achieve better off-design performance and economic performance than a solar-only thermal Power Plant.
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integrating mid temperature solar heat and post combustion co2 capture in a coal Fired Power Plant
Solar Energy, 2012Co-Authors: Yawen Zhao, Hui Hong, Xiaosong ZhangAbstract:Abstract This article proposed a hybrid Power system combining mid-temperature solar heat and a coal-Fired Power Plant for CO2 capture. In this system, solar heat at around 300 °C replaces the high-quality steam extractions of the Rankine cycle to heat the feed water, so the steam that was to be extracted can expand efficiently in the high-pressure turbines. In this hybrid system, the CO2 capture penalty is completely compensated for by the enhanced work output contributed by the solar heat. The annual solar field cost is reduced to 10.8 $/ton-CO2, compared to 25.8 $/ton-CO2 in a system with solar heat for direct solvent regeneration. Additionally, the mid-temperature solar heat is converted into work with an improved efficiency of 27%. Thus, this system offers a promising approach to reduce the CO2 capture penalty in CCS with attractive cost-effective utilization of mid-temperature solar heat.
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proposed partial rePowering of a coal Fired Power Plant using low grade solar thermal energy
International Journal of Thermodynamics, 2011Co-Authors: Hui Hong, Yawen Zhao, Hongguang JinAbstract:In this paper, a hybrid Power-generation system with integration of solar heat at approximately 300 ⁰C was proposed for a coal-Fired Power Plant. The system was investigated with the aid of energy-utilization diagram methodology (EUD methodology). In this research, instead of steam, low-grade solar heat was utilized to heat the feed water, leading to an improvement in the Plant thermodynamic performance. The net annual solar-to-electric efficiency was recorded as over 15%. Solar feed-water heaters can operate in line with previously used feed-water heaters during the solar off-design period. A preliminary economic evaluation demonstrated that the increased capital cost of the solar collectors may be approximately $2,007/kWe. The promising results indicated that the proposed thermal cycle offers an approach that integrates mid-temperature solar heat to partially rePower existing coal-Fired Power Plants.