A significant number of salt caverns have high proportions of insoluble sediments,but the thermal storage utilization potential of insoluble sediments remains understudied within current research.Therefore,this study ...A significant number of salt caverns have high proportions of insoluble sediments,but the thermal storage utilization potential of insoluble sediments remains understudied within current research.Therefore,this study aims to explore the feasibility of an integrated compressed-air energy storage(CAES)coupled with insoluble sediment as the thermal storage media for salt caverns.In order to fulfill this objective,this study presents two steps to analyze the insoluble sediment's thermo-mechanical behavior under ordinary CAES conditions and coupled thermal energy storage(TES)conditions separately.A multiphysics-coupled numerical model was developed to investigate the thermal behavior of insoluble sediments at different heights.Then,a dual-cavity model with a sediment-filled channel was constructed to study the heat storage process in long-and short-term modes.Results demonstrated that sediment effectively protected cavern walls from thermal shocks caused by compressed air,maintaining temperature differentials within 1 K.Dual-cavity simulations revealed the sediment's capability to mitigate the temperature fluctuation of compressed air in caverns,achieving a 66% temperature reduction in the outflow interface during operation.The findings confirmed the feasibility of utilizing insoluble sediments for long-term thermal storage applications involving thermal cycles with ΔT=150 K,attaining a heat storage density of 50 kW·h/m^(3).The results show that the heat capacity of the sediment contributes to the cavern wall's stability and provide references for developing integrated CAES-TES systems in sediment-filled salt caverns.展开更多
China will strive to achieve a‘dual carbon’target:‘carbon peak’by 2030 and‘carbon-neutral’by 2060.In this context,improving the efficiency of renewable energy and reducing the use of thermal power are important ...China will strive to achieve a‘dual carbon’target:‘carbon peak’by 2030 and‘carbon-neutral’by 2060.In this context,improving the efficiency of renewable energy and reducing the use of thermal power are important ways to achieve the target.Clean,efficient and large-capacity energy-storage technology is the key to improving the utilization rate of renewable energy.First,this paper proposes to use compressed-air energy-storage technology instead of the old energy-storage technology to build an economical and environmentally friendly comprehensive energy park capacity optimization configuration model.Second,this paper uses the newly proposed improved chicken swarm optimization algorithm to solve the model,which is more accurate and faster.Finally,this paper analyzes a comprehensive energy park in north-west China.Through case analysis,it can be seen that the average utilization rate of renewable energy can reach 73.87%through the model proposed in this paper,while the average power-abandonment rate is only 9.32%.展开更多
As the core equipment in power systems,ultra-high voltage(UHV)transformers pose a high fire risk.The compressed-air foam spray nozzle is a novel end-release device that,due to its high efficiency and excellent suppres...As the core equipment in power systems,ultra-high voltage(UHV)transformers pose a high fire risk.The compressed-air foam spray nozzle is a novel end-release device that,due to its high efficiency and excellent suppression effect on oil-based fires,has been increasingly applied in UHV substations.This study is based on a self-developed experimental platform for compressed-air foam firefighting systems.To meet practical engineering needs,the longitudinal maximum of the contour line at the threshold of 12 L/(min·m²)was selected as the spray range.The study systematically explored the factors influencing the spray range of the spray nozzle.Experimental results revealed that when the hole elevation angle was 60°,the average spray range increased by 59%compared to 0°.When the nozzle aperture was 10 mm and the outlet pressure was 0.15 MPa,the spray range improved by 17%.Additionally,as the outlet pressure increased,the foam spray range grew significantly,with a 35.2% increase at 0.3 MPa compared to 0.1 MPa,indicating that the outlet pressure had a substantial effect on the spray range.To predict the spray range increase,an empirical model is developed for the outlet pressure versus the spray range.After analyzing the above three influencing factors,all the data of various working conditions were integrated into a single dataset,a prediction model of the spray range was established,and the importance of the factors affecting the range was ranked.These findings provide a theoretical foundation for the optimized design and engineering application of compressed-air foam systems(CAFSs).展开更多
Thermo-mechanical energy storage(TMES)technologies have attracted significant attention due to their potential for grid-scale,long-duration electricity storage,offering advantages such as minimal geographical constrai...Thermo-mechanical energy storage(TMES)technologies have attracted significant attention due to their potential for grid-scale,long-duration electricity storage,offering advantages such as minimal geographical constraints,low environmental impact,and long operational lifespans.A key benefit of TMES systems is their ability to perform energy conversion steps that enable interaction with both thermal energy consumers and prosumers,effectively functioning as combined cooling,heating and power(CCHP)systems.This paper reviews recent progress in various TMES technologies,focusing on compressed-air energy storage(CAES),liquid-air energy storage(LAES),pumped-thermal electricity storage(PTES,also known as Carnot battery),and carbon dioxide energy storage(CES),while exploring their potential applications as extended CCHP systems for trigeneration.Techno-economic analysis indicate that TMES-based CCHP systems can achieve roundtrip(power-to-power)efficiencies ranging from 40%to 130%,overall(trigeneration)energy efficiencies from 70%to 190%,and a levelized cost of energy(with cooling and heating outputs converted into equivalent electricity)between 70 and 200$/MWh.In general,the evolution of TMES-based CCHP systems into smart multi-energy management systems for cities or districts in the future is a highly promising avenue.However,current economic analyses remain incomplete,and further exploration is needed,especially in the area“AI for energy storage,”which is crucial for the widespread adoption of TMES-based CCHP systems.展开更多
The weather-dependent uncertainty of wind and solar power generation presents a challenge to the balancing of power generation and demand in highly renewable electricity systems.Battery energy storage can provide flex...The weather-dependent uncertainty of wind and solar power generation presents a challenge to the balancing of power generation and demand in highly renewable electricity systems.Battery energy storage can provide flexibility to firm up the variability of renewables and to respond to the increased load demand under decarbonization scenarios.This paper explores how the battery energy storage capacity requirement for compressed-air energy storage(CAES)will grow as the load demand increases.Here we used an idealized lowest-cost optimization model to study the response of highly renewable electricity systems to the increasing load demand of California under deep decarbonization.Results show that providing bulk CAES to the zero-emission power system offers substantial benefits,but it cannot fully compensate for the 100%variability of highly renewable power systems.The capacity requirement of CAES increases by≤33.3%with a 1.5 times increase in the load demand and by≤50%with a two-times increase in the load demand.In this analysis,a zero-emission electricity system operating at current costs becomes more cost-effective when there is firm power generation.The least competitive nuclear option plays this role and reduces system costs by 16.4%,curtails the annual main node by 36.8%,and decreases the CAES capacity requirements by≤80.7%in the case of a double-load demand.While CAES has potential in addressing renewable variability,its widespread deployment is constrained by geographical,societal,and economic factors.Therefore,if California is aiming for an energy system that is reliant on wind and solar power,then an additional dispatchable power source other than CAES or similar load flexibility is necessary.To fully harness the benefits of bulk CAES,the development and implementation of cost-effective approaches are crucial in significantly reducing system costs.展开更多
A new compressed-air engine system based on three-stage single screw expander was proposed to improve the performance of power system.Three different structure styles were presented,and the studies on the power perfor...A new compressed-air engine system based on three-stage single screw expander was proposed to improve the performance of power system.Three different structure styles were presented,and the studies on the power performance and the distribution of expansion ratios between stages were carried out by programming and mathematical modeling of each style.Research results indicated that the best matches of expansion ratios with equal heat temperature for the air tank of pressure 30 MPa were seven-five-three for"first-stage heating"style,eight-five-three for"two-stage heating"style and five-five-four for"three-stage heating"style,respectively.Results also showed that heating up inlet air or increasing the expander efficiency might improve the power performance.The output power of the"two-stage heating"style is far higher than that of"first-stage heating"style and is a little lower than that of"three-stage heating"style.The new system showed good structure and power performances.展开更多
基金National Natural Science Foundation of China,Grant/Award Number:52090081 and 42477180Beijing Nova Program,Grant/Award Number:20250484906+2 种基金National Science and Technology Major Project of China,Grant/Award Number:2024ZD1003600SINOPEC Science and Technology Department Project,Grant/Award Number:P25006Young Elite Scientist Sponsorship Program by China Association for Science and Technology,Grant/Award Number:YESS20220300。
文摘A significant number of salt caverns have high proportions of insoluble sediments,but the thermal storage utilization potential of insoluble sediments remains understudied within current research.Therefore,this study aims to explore the feasibility of an integrated compressed-air energy storage(CAES)coupled with insoluble sediment as the thermal storage media for salt caverns.In order to fulfill this objective,this study presents two steps to analyze the insoluble sediment's thermo-mechanical behavior under ordinary CAES conditions and coupled thermal energy storage(TES)conditions separately.A multiphysics-coupled numerical model was developed to investigate the thermal behavior of insoluble sediments at different heights.Then,a dual-cavity model with a sediment-filled channel was constructed to study the heat storage process in long-and short-term modes.Results demonstrated that sediment effectively protected cavern walls from thermal shocks caused by compressed air,maintaining temperature differentials within 1 K.Dual-cavity simulations revealed the sediment's capability to mitigate the temperature fluctuation of compressed air in caverns,achieving a 66% temperature reduction in the outflow interface during operation.The findings confirmed the feasibility of utilizing insoluble sediments for long-term thermal storage applications involving thermal cycles with ΔT=150 K,attaining a heat storage density of 50 kW·h/m^(3).The results show that the heat capacity of the sediment contributes to the cavern wall's stability and provide references for developing integrated CAES-TES systems in sediment-filled salt caverns.
文摘China will strive to achieve a‘dual carbon’target:‘carbon peak’by 2030 and‘carbon-neutral’by 2060.In this context,improving the efficiency of renewable energy and reducing the use of thermal power are important ways to achieve the target.Clean,efficient and large-capacity energy-storage technology is the key to improving the utilization rate of renewable energy.First,this paper proposes to use compressed-air energy-storage technology instead of the old energy-storage technology to build an economical and environmentally friendly comprehensive energy park capacity optimization configuration model.Second,this paper uses the newly proposed improved chicken swarm optimization algorithm to solve the model,which is more accurate and faster.Finally,this paper analyzes a comprehensive energy park in north-west China.Through case analysis,it can be seen that the average utilization rate of renewable energy can reach 73.87%through the model proposed in this paper,while the average power-abandonment rate is only 9.32%.
基金supported by the Science and Technology Project of State Grid Anhui Electric Corporation of China(Grant No.52120523000L).
文摘As the core equipment in power systems,ultra-high voltage(UHV)transformers pose a high fire risk.The compressed-air foam spray nozzle is a novel end-release device that,due to its high efficiency and excellent suppression effect on oil-based fires,has been increasingly applied in UHV substations.This study is based on a self-developed experimental platform for compressed-air foam firefighting systems.To meet practical engineering needs,the longitudinal maximum of the contour line at the threshold of 12 L/(min·m²)was selected as the spray range.The study systematically explored the factors influencing the spray range of the spray nozzle.Experimental results revealed that when the hole elevation angle was 60°,the average spray range increased by 59%compared to 0°.When the nozzle aperture was 10 mm and the outlet pressure was 0.15 MPa,the spray range improved by 17%.Additionally,as the outlet pressure increased,the foam spray range grew significantly,with a 35.2% increase at 0.3 MPa compared to 0.1 MPa,indicating that the outlet pressure had a substantial effect on the spray range.To predict the spray range increase,an empirical model is developed for the outlet pressure versus the spray range.After analyzing the above three influencing factors,all the data of various working conditions were integrated into a single dataset,a prediction model of the spray range was established,and the importance of the factors affecting the range was ranked.These findings provide a theoretical foundation for the optimized design and engineering application of compressed-air foam systems(CAFSs).
基金supported by the National Natural Science Foundation of China(Grant No.51906150)the Future Foundation of Energy Science(Grant No.WLNY-MS-2022-010)+1 种基金the Open Fund Project of State Key Laboratory of Clean Energy Utilization(Grant No.ZJUCEU2022022)the UK Engineering and Physical Sciences Research Council(EPSRC)(Grant Nos.EP/Y017471/1,and EP/S032622/1].
文摘Thermo-mechanical energy storage(TMES)technologies have attracted significant attention due to their potential for grid-scale,long-duration electricity storage,offering advantages such as minimal geographical constraints,low environmental impact,and long operational lifespans.A key benefit of TMES systems is their ability to perform energy conversion steps that enable interaction with both thermal energy consumers and prosumers,effectively functioning as combined cooling,heating and power(CCHP)systems.This paper reviews recent progress in various TMES technologies,focusing on compressed-air energy storage(CAES),liquid-air energy storage(LAES),pumped-thermal electricity storage(PTES,also known as Carnot battery),and carbon dioxide energy storage(CES),while exploring their potential applications as extended CCHP systems for trigeneration.Techno-economic analysis indicate that TMES-based CCHP systems can achieve roundtrip(power-to-power)efficiencies ranging from 40%to 130%,overall(trigeneration)energy efficiencies from 70%to 190%,and a levelized cost of energy(with cooling and heating outputs converted into equivalent electricity)between 70 and 200$/MWh.In general,the evolution of TMES-based CCHP systems into smart multi-energy management systems for cities or districts in the future is a highly promising avenue.However,current economic analyses remain incomplete,and further exploration is needed,especially in the area“AI for energy storage,”which is crucial for the widespread adoption of TMES-based CCHP systems.
文摘The weather-dependent uncertainty of wind and solar power generation presents a challenge to the balancing of power generation and demand in highly renewable electricity systems.Battery energy storage can provide flexibility to firm up the variability of renewables and to respond to the increased load demand under decarbonization scenarios.This paper explores how the battery energy storage capacity requirement for compressed-air energy storage(CAES)will grow as the load demand increases.Here we used an idealized lowest-cost optimization model to study the response of highly renewable electricity systems to the increasing load demand of California under deep decarbonization.Results show that providing bulk CAES to the zero-emission power system offers substantial benefits,but it cannot fully compensate for the 100%variability of highly renewable power systems.The capacity requirement of CAES increases by≤33.3%with a 1.5 times increase in the load demand and by≤50%with a two-times increase in the load demand.In this analysis,a zero-emission electricity system operating at current costs becomes more cost-effective when there is firm power generation.The least competitive nuclear option plays this role and reduces system costs by 16.4%,curtails the annual main node by 36.8%,and decreases the CAES capacity requirements by≤80.7%in the case of a double-load demand.While CAES has potential in addressing renewable variability,its widespread deployment is constrained by geographical,societal,and economic factors.Therefore,if California is aiming for an energy system that is reliant on wind and solar power,then an additional dispatchable power source other than CAES or similar load flexibility is necessary.To fully harness the benefits of bulk CAES,the development and implementation of cost-effective approaches are crucial in significantly reducing system costs.
基金supported by the National Natural Science Foundation of China(Grant No.50976004)
文摘A new compressed-air engine system based on three-stage single screw expander was proposed to improve the performance of power system.Three different structure styles were presented,and the studies on the power performance and the distribution of expansion ratios between stages were carried out by programming and mathematical modeling of each style.Research results indicated that the best matches of expansion ratios with equal heat temperature for the air tank of pressure 30 MPa were seven-five-three for"first-stage heating"style,eight-five-three for"two-stage heating"style and five-five-four for"three-stage heating"style,respectively.Results also showed that heating up inlet air or increasing the expander efficiency might improve the power performance.The output power of the"two-stage heating"style is far higher than that of"first-stage heating"style and is a little lower than that of"three-stage heating"style.The new system showed good structure and power performances.
