The green transition of power systems relies on the accurate measurement of the economic cost associated with the deep peak-shaving process in coal-fired power plants. To evaluate the variation in the coal consumption...The green transition of power systems relies on the accurate measurement of the economic cost associated with the deep peak-shaving process in coal-fired power plants. To evaluate the variation in the coal consumption rate during low-load operation, a model of a 300 MW coal-fired unit was established, with less than 1% deviation from the actual operation value. The results indicate that the coal consumption rate at 20% load can increase to 1.48 times the full-load value. When the excess air coefficient is reduced by 0.3 at low-load conditions, between 40% and 20% load, the exhaust gas temperature is reduced by approximately 5℃, leading to a decrease in the coal consumption rate. In addition, elevating the steam temperature to the design value can reduce the coal consumption rate by 6% to 13%, and increase the inlet temperature of Selective Catalytic Reduction (SCR) process by 10℃. Improving the turbine efficiency during peak-shaving significantly reduces the coal consumption cost, and the enhancement of the mean steam temperature is an efficient approach. This study offers a theoretical reference for the retrofitting, design and economic operation of coal-fired units in peak-shaving, thereby supporting energy system transitions.展开更多
Integrating a high proportion of intermittent renewable energy provides a solution for the higher peak-shaving capacity of coal-fired power plants.Oxy-fuel combustion is one of the most promising carbon reduction tech...Integrating a high proportion of intermittent renewable energy provides a solution for the higher peak-shaving capacity of coal-fired power plants.Oxy-fuel combustion is one of the most promising carbon reduction technologies for coal-fired power plants.This study has proposed a novel oxy-fuel power plant that is coupled with both liquid O_(2)storage and cold energy recovery systems in order to adapt to the peak-shaving requirements.The liquid O_(2)storage system uses cheap valley electricity to produce liquid O_(2)for a later use in the peak period to enhance the peak-shaving capacity.Meanwhile,the cold energy recovery system has been introduced to recover the physical latent energy during the phase change of liquid O_(2)to increase the power generation in the peak period.Technical economies of three power plants,i.e.a 330 MW(e)oxy-fuel power plant as reference(Case 1),the same power plant coupled with only liquid O_(2)storage system(Case 2),and the same power plant coupled with both liquid O_(2)storage and cold energy recovery systems(Case 3),have been analyzed and compared.Thermodynamic performance analysis indicates that the peaking capacity of Case 3 can reach the range of 106.03 to 294.22 MW(e),and the maximum peak-shaving coefficient can be as high as 2.77.Exergy analysis demonstrates that the gross exergy efficiency of Cases 2 and 3 reaches 32.18%and 33.57%,respectively,in the peak period,which are significantly higher than that of 26.70%in Case 1.Economic analysis shows that through selling the liquid O_(2)and liquid CO_(2),combined with carbon trading,the levelized cost of electricity(LCOE)of the three cases have been greatly reduced,with the lowest one of 30.90 USD/MWh shown in Case 3.For a comprehensive consideration,Case 3 can be considered a future reference of oxy-fuel power plant with the best thermodynamic and economic performance.展开更多
This work proposes an optimization method for gas storage operation parameters under multi-factor coupled constraints to improve the peak-shaving capacity of gas storage reservoirs while ensuring operational safety.Pr...This work proposes an optimization method for gas storage operation parameters under multi-factor coupled constraints to improve the peak-shaving capacity of gas storage reservoirs while ensuring operational safety.Previous research primarily focused on integrating reservoir,wellbore,and surface facility constraints,often resulting in broad constraint ranges and slow model convergence.To solve this problem,the present study introduces additional constraints on maximum withdrawal rates by combining binomial deliverability equations with material balance equations for closed gas reservoirs,while considering extreme peak-shaving demands.This approach effectively narrows the constraint range.Subsequently,a collaborative optimization model with maximum gas production as the objective function is established,and the model employs a joint solution strategy combining genetic algorithms and numerical simulation techniques.Finally,this methodology was applied to optimize operational parameters for Gas Storage T.The results demonstrate:(1)The convergence of the model was achieved after 6 iterations,which significantly improved the convergence speed of the model;(2)The maximum working gas volume reached 11.605×10^(8) m^(3),which increased by 13.78%compared with the traditional optimization method;(3)This method greatly improves the operation safety and the ultimate peak load balancing capability.The research provides important technical support for the intelligent decision of injection and production parameters of gas storage and improving peak load balancing ability.展开更多
Underground gas storage(UGS)is one of the major storage and peak-shaving means in the world among numerous storage ways via gas fields,small-scale LNG,etc.With the rapid development of natural gas industry in China,th...Underground gas storage(UGS)is one of the major storage and peak-shaving means in the world among numerous storage ways via gas fields,small-scale LNG,etc.With the rapid development of natural gas industry in China,the seasonal peak-shaving issues are increasingly prominent,so how to achieve sustainable development of UGS business has become a major problem at present.In view of this,we studied the present status and trend of UGS development abroad and analyzed the following challenges encountered by UGS in China.(1)UGS construction falls behind the world and peak-shaving capacity is insufficient.(2)There is lack of quality gas sources for storage and the complicated geological conditions make the cost of UGS construction high.(3)UGS construction is still at the preliminary stage,so experience is not enough in safety and scientific operation and management.(4)UGS construction,management and operation are not unified as a whole,so its maximum efficiency fails to be exerted.(5)The economic benefit of UGS is difficult to be shown without independent cost accounting.Based on the experience of other countries,some proposals were put forward on UGS development under the actual present situation:to strengthen strategic UGS layout,intensify storage site screening in key areas and steadily promote UGS construction;to establish professional UGS technical and management teams and intensify the research of key technologies;and to set up a complete and rationally-distributed UGS construction,operation and management system.展开更多
Faced with the global warming trend,many coal-frontier countries including China have gradually come to develop flexible power generation to support a novel energy system with increasing renewable energy.While the exi...Faced with the global warming trend,many coal-frontier countries including China have gradually come to develop flexible power generation to support a novel energy system with increasing renewable energy.While the existing literature extensively discusses various technologies of flexible coal-fired power generation and energy storage,there remains a critical gap in systematic research that holistically assesses the current landscape of flexible generation technologies in coal-fired power plants while delineating actionable pathways for their evolution in low-carbon energy systems.In this paper,current situations from combustion side and pulverized coal side retrofit,wide load denitrification retrofit,turbine side flexibility retrofit,and energy storage coupled peak shifting and fast variable load response technology are illustrated first respectively.In addition,this paper presents a new perspective on the future direction of flexibility retrofit,including the integration of energy storage to enhance operational flexibility.This review can provide a reference for the research and development of deep peak-shaving and flexible retrofit technologies for power generation for pulverized coal boiler generating units in the future.展开更多
We proposed a novel efficient operation scheme for a thermal power plant’s air-cooling system based on peak shaving, in order to cope with high ambient temperature in summer. We introduced an absorptiongeneration equ...We proposed a novel efficient operation scheme for a thermal power plant’s air-cooling system based on peak shaving, in order to cope with high ambient temperature in summer. We introduced an absorptiongeneration equipment with water/lithium working pairs into the air cooled condenser(ACC) to reconstruct the traditional thermal power plant, and established a dynamic thermodynamic model adopting Ebsilon code. We studied the thermodynamic performance variation of the reconstructed thermal power plant throughout a 24-hour cycle and found that the fluctuation ratio of the turbine back pressure decreased to 6% from 78%, which is beneficial for the stable and safe operation of the electric power system. The thermal performance improvement benefited from the exploitation of the heat transfer potential of ACC, which realized via cold duty schedule throughout the day, under different ambient temperature conditions. In this system, the generated power was higher at relatively high ambient temperature than that at relatively low ambient temperature, which solved the electricity demand-supply imbalance problem under high ambient temperature. Finally, the same optimization effects for power thermal plants with an indirect air-cooling system were obtained using the same operation scheme.展开更多
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDA 29010500)the Special Research Assistant Project of the Chinese Academy of Sciences.
文摘The green transition of power systems relies on the accurate measurement of the economic cost associated with the deep peak-shaving process in coal-fired power plants. To evaluate the variation in the coal consumption rate during low-load operation, a model of a 300 MW coal-fired unit was established, with less than 1% deviation from the actual operation value. The results indicate that the coal consumption rate at 20% load can increase to 1.48 times the full-load value. When the excess air coefficient is reduced by 0.3 at low-load conditions, between 40% and 20% load, the exhaust gas temperature is reduced by approximately 5℃, leading to a decrease in the coal consumption rate. In addition, elevating the steam temperature to the design value can reduce the coal consumption rate by 6% to 13%, and increase the inlet temperature of Selective Catalytic Reduction (SCR) process by 10℃. Improving the turbine efficiency during peak-shaving significantly reduces the coal consumption cost, and the enhancement of the mean steam temperature is an efficient approach. This study offers a theoretical reference for the retrofitting, design and economic operation of coal-fired units in peak-shaving, thereby supporting energy system transitions.
基金financially supported by the National Key Research and Development Program of China(2022YFE0206600)the research project of Inner Mongolia Power Research Institute(2022-ZC-08)。
文摘Integrating a high proportion of intermittent renewable energy provides a solution for the higher peak-shaving capacity of coal-fired power plants.Oxy-fuel combustion is one of the most promising carbon reduction technologies for coal-fired power plants.This study has proposed a novel oxy-fuel power plant that is coupled with both liquid O_(2)storage and cold energy recovery systems in order to adapt to the peak-shaving requirements.The liquid O_(2)storage system uses cheap valley electricity to produce liquid O_(2)for a later use in the peak period to enhance the peak-shaving capacity.Meanwhile,the cold energy recovery system has been introduced to recover the physical latent energy during the phase change of liquid O_(2)to increase the power generation in the peak period.Technical economies of three power plants,i.e.a 330 MW(e)oxy-fuel power plant as reference(Case 1),the same power plant coupled with only liquid O_(2)storage system(Case 2),and the same power plant coupled with both liquid O_(2)storage and cold energy recovery systems(Case 3),have been analyzed and compared.Thermodynamic performance analysis indicates that the peaking capacity of Case 3 can reach the range of 106.03 to 294.22 MW(e),and the maximum peak-shaving coefficient can be as high as 2.77.Exergy analysis demonstrates that the gross exergy efficiency of Cases 2 and 3 reaches 32.18%and 33.57%,respectively,in the peak period,which are significantly higher than that of 26.70%in Case 1.Economic analysis shows that through selling the liquid O_(2)and liquid CO_(2),combined with carbon trading,the levelized cost of electricity(LCOE)of the three cases have been greatly reduced,with the lowest one of 30.90 USD/MWh shown in Case 3.For a comprehensive consideration,Case 3 can be considered a future reference of oxy-fuel power plant with the best thermodynamic and economic performance.
基金supported by the Science and Technology Research Program of Chongqing Municipal Education Commission(KJQN202401501,KJZD-M202401501).
文摘This work proposes an optimization method for gas storage operation parameters under multi-factor coupled constraints to improve the peak-shaving capacity of gas storage reservoirs while ensuring operational safety.Previous research primarily focused on integrating reservoir,wellbore,and surface facility constraints,often resulting in broad constraint ranges and slow model convergence.To solve this problem,the present study introduces additional constraints on maximum withdrawal rates by combining binomial deliverability equations with material balance equations for closed gas reservoirs,while considering extreme peak-shaving demands.This approach effectively narrows the constraint range.Subsequently,a collaborative optimization model with maximum gas production as the objective function is established,and the model employs a joint solution strategy combining genetic algorithms and numerical simulation techniques.Finally,this methodology was applied to optimize operational parameters for Gas Storage T.The results demonstrate:(1)The convergence of the model was achieved after 6 iterations,which significantly improved the convergence speed of the model;(2)The maximum working gas volume reached 11.605×10^(8) m^(3),which increased by 13.78%compared with the traditional optimization method;(3)This method greatly improves the operation safety and the ultimate peak load balancing capability.The research provides important technical support for the intelligent decision of injection and production parameters of gas storage and improving peak load balancing ability.
文摘Underground gas storage(UGS)is one of the major storage and peak-shaving means in the world among numerous storage ways via gas fields,small-scale LNG,etc.With the rapid development of natural gas industry in China,the seasonal peak-shaving issues are increasingly prominent,so how to achieve sustainable development of UGS business has become a major problem at present.In view of this,we studied the present status and trend of UGS development abroad and analyzed the following challenges encountered by UGS in China.(1)UGS construction falls behind the world and peak-shaving capacity is insufficient.(2)There is lack of quality gas sources for storage and the complicated geological conditions make the cost of UGS construction high.(3)UGS construction is still at the preliminary stage,so experience is not enough in safety and scientific operation and management.(4)UGS construction,management and operation are not unified as a whole,so its maximum efficiency fails to be exerted.(5)The economic benefit of UGS is difficult to be shown without independent cost accounting.Based on the experience of other countries,some proposals were put forward on UGS development under the actual present situation:to strengthen strategic UGS layout,intensify storage site screening in key areas and steadily promote UGS construction;to establish professional UGS technical and management teams and intensify the research of key technologies;and to set up a complete and rationally-distributed UGS construction,operation and management system.
基金supported by Major Science and Technology Projects of Xinjiang Uygur Autonomous Region[grant number 2023A01005-2]Youth Support Project of Tianshan Talents Training Program of Xinjiang Uygur Autonomous Region[grant number 2024TSYCQNTJ0018].
文摘Faced with the global warming trend,many coal-frontier countries including China have gradually come to develop flexible power generation to support a novel energy system with increasing renewable energy.While the existing literature extensively discusses various technologies of flexible coal-fired power generation and energy storage,there remains a critical gap in systematic research that holistically assesses the current landscape of flexible generation technologies in coal-fired power plants while delineating actionable pathways for their evolution in low-carbon energy systems.In this paper,current situations from combustion side and pulverized coal side retrofit,wide load denitrification retrofit,turbine side flexibility retrofit,and energy storage coupled peak shifting and fast variable load response technology are illustrated first respectively.In addition,this paper presents a new perspective on the future direction of flexibility retrofit,including the integration of energy storage to enhance operational flexibility.This review can provide a reference for the research and development of deep peak-shaving and flexible retrofit technologies for power generation for pulverized coal boiler generating units in the future.
基金Financial support from the National Natural Science Foundation of China(NSFC)project(Grant No.51806217)International Cooperation Project(Grant No.2016YFE0118100)Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDA 21010201)is gratefully acknowledged.
文摘We proposed a novel efficient operation scheme for a thermal power plant’s air-cooling system based on peak shaving, in order to cope with high ambient temperature in summer. We introduced an absorptiongeneration equipment with water/lithium working pairs into the air cooled condenser(ACC) to reconstruct the traditional thermal power plant, and established a dynamic thermodynamic model adopting Ebsilon code. We studied the thermodynamic performance variation of the reconstructed thermal power plant throughout a 24-hour cycle and found that the fluctuation ratio of the turbine back pressure decreased to 6% from 78%, which is beneficial for the stable and safe operation of the electric power system. The thermal performance improvement benefited from the exploitation of the heat transfer potential of ACC, which realized via cold duty schedule throughout the day, under different ambient temperature conditions. In this system, the generated power was higher at relatively high ambient temperature than that at relatively low ambient temperature, which solved the electricity demand-supply imbalance problem under high ambient temperature. Finally, the same optimization effects for power thermal plants with an indirect air-cooling system were obtained using the same operation scheme.
