In order to address the synergistic optimization of energy efficiency improvement in the waste incineration power plant(WIPP)and renewable energy accommodation,an electricity-hydrogen-waste multi-energy system integra...In order to address the synergistic optimization of energy efficiency improvement in the waste incineration power plant(WIPP)and renewable energy accommodation,an electricity-hydrogen-waste multi-energy system integrated with phase change material(PCM)thermal storage is proposed.First,a thermal energy management framework is constructed,combining PCM thermal storage with the alkaline electrolyzer(AE)waste heat recovery and the heat pump(HP),while establishing a PCM-driven waste drying system to enhance the efficiency of waste incineration power generation.Next,a flue gas treatment method based on purification-separation-storage coordination is adopted,achieving spatiotemporal decoupling between waste incineration and flue gas treatment.Subsequently,a two-stage optimal dispatching strategy for the multi-energy system is developed:the first stage establishes a dayahead economic dispatch model with the objective of minimizing net system costs,while the second stage introduces model predictive control(MPC)to realize intraday rolling optimization.Finally,The optimal dispatching strategies under different scenarios are obtained using the Gurobi solver,followed by a comparative analysis of the optimized operational outcomes.Simulation results demonstrate that the proposed system optimizes the output and operational states of each unit,simultaneously reducing carbon trading costs while increasing electricity sales revenue.The proposed scheduling strategy demonstrates effective grid peak-shaving functionality,thereby simultaneously improving the system’s economic performance and operational flexibility while providing an innovative technical pathway for municipal solid waste(MSW)resource utilization and low-carbon transformation of energy systems.展开更多
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
High-temperature phase change materials(PCMs)have attracted significant attention in the field of thermal energy storage due to their ability to store and release large amounts of heat within a small temperature fluct...High-temperature phase change materials(PCMs)have attracted significant attention in the field of thermal energy storage due to their ability to store and release large amounts of heat within a small temperature fluctuation range.However,their practical application is limited due to problems such as leakage,corrosion,and volume changes at high temperatures.Recent research has shown that macroencapsulation technology holds promise in addressing these issues.This paper focuses on the macroencapsulation technology of high-temperature PCMs,starting with a review of the classification and development history of high-temperature macroencapsulatd PCMs.Four major encapsulation strategies,including electroplating method,solid/liquid filling method,sacrificial material method,and powder compaction into sphere method,are then summarized.The methods for effectively addressing issues such as corrosion,leakage,supercooling,and phase separation in PCMs are analyzed,along with approaches for improving the heat transfer performance,mechanical strength,and thermal cycling stability of macrocapsules.Subsequently,the structure and packing arrangement optimization of macrocapsules in thermal storage systems is discussed in detail.Finally,after comparing the performance of various encapsulation strategies and summarizing existing issues,the current technical challenges,improvement methods,and future development directions are proposed.More attention should be given to utilizing AI technology and reinforcement learning to reveal the multiphysics-coupled heat and mass transfer mechanisms in macrocapsule applications,as well as to optimize material selection and encapsulation parameters,thereby enhancing the overall efficiency of thermal storage systems.展开更多
This article,based on authors＇ long-term study,proposes an improved foamed-Ni-packed phase-change thermal storage canister,which takes advantage of the foamed-Ni characteristic of instinctive porous structure and exc...This article,based on authors＇ long-term study,proposes an improved foamed-Ni-packed phase-change thermal storage canister,which takes advantage of the foamed-Ni characteristic of instinctive porous structure and excellent properties to ameliorate its void distribution and thermal conductivity. The improved canister and the unimproved one without foamed-Ni package,are put to heat absorbing and releasing tests to investigate the effects of heat absorbing temperature upon the phase-change materials （PCM） melting time under three temperature schemes by using platinum resistance thermometers （PT100） and data acquisition modules （ADAM-4000） to gather the data of varying temperature. Afterwards,the computerized tomography （CT） is employed to scan the void distribution in both canisters. Compared to the unimproved canister,the experimental results evidence the superiority of the improved one in higher uniformity in void and temperature distribution as well as faster thermal responses.展开更多
Rapid advances in thermal management technology and the increasing need for multi-energy conversion have placed stringent energy efficiency requirements on next-generation shape-stable composite phase change materials...Rapid advances in thermal management technology and the increasing need for multi-energy conversion have placed stringent energy efficiency requirements on next-generation shape-stable composite phase change materials(PCMs).Magnetically-responsive phase change thermal storage materials are considered an emerging concept for energy storage systems,enabling PCMs to perform unprecedented functions(such as green energy utilization,magnetic thermotherapy,drug release,etc.).The combination of multifunctional magnetic nanomaterials and PCMs is a milestone in the creation of advanced multifunctional composite PCMs.However,a timely and comprehensive review of composite PCMs based on magnetic nanoparticle modification is still missing.Herein,we furnish an exhaustive exposition elucidating the cutting-edge advancements in magnetically responsive composite PCMs.We delve deeply into the multifarious roles assumed by distinct nanoparticles within composite PCMs of varying dimensions,meticulously scrutinizing the intricate interplay between their architectures and thermophysical attributes.Moreover,we prognosticate future research trajectories,delineate alternative stratagems,and illuminate prospective avenues.This review is intended to stimulate broader academic interest in interdisciplinary fields and provide valuable insights into the development of next-generation magnetically-responsive composite PCMs.展开更多
For improving the properties of SiC-mullite composite ceramics used for solar sensible thermal storage, MnO2 was introduced as sintering additive when preparing. The composite ceramics were synthesized by using SiC, a...For improving the properties of SiC-mullite composite ceramics used for solar sensible thermal storage, MnO2 was introduced as sintering additive when preparing. The composite ceramics were synthesized by using SiC, andalusite, a-Al2O3 as the starting materials with non-contact graphite-buried sintering method. Phase composition and microstructure of the composites were investigated by XRD and SEM, and the effect of MnOz on the properties of SiC composites was studied. Results indicated that samples SM1 with 0.2 wt% MnO2 addition achieved the optimum properties： bending strength of 70.96 MPa, heat capacity of 1.02 J.（g.K）-1, thermal conductivity of 9.05 W-（m.K）-1. Proper addition of MnO2 was found to weaken the volume effect of the composites and improve the thermal shock resistance with an increased rate of 27.84% for bending strength after 30 cycles of thermal shock （air cooling from 1 100 ℃ to RT）. Key words： SiC-mullite composite ceramics; MnO2; solar sensible thermal storage; non-contact graphite-buried sintering; thermal shock resistance展开更多
The effect of LaNi on thermal storage properties of MgH2 prepared by ball milling under hydrogen atmosphere was investigated.The thermal storage properties,cyclic property and thermal storage mechanism were studied by...The effect of LaNi on thermal storage properties of MgH2 prepared by ball milling under hydrogen atmosphere was investigated.The thermal storage properties,cyclic property and thermal storage mechanism were studied by pres sure-composition-temperature(PC T),X-ray diffraction(XRD)and transmission electron microscopy(TEM).The Van't Hoff curve indicates that the formation enthalpy of Mg-16 wt%LaNi is 74.62 kJ·mol^(-1),which approaches to the theoretical values of MgH2.The isothermal measurement indicates that Mg-16 wt%LaNi can absorb 6.263 wt%H_(2)within 30 min at 390℃for the first absorption,the absorption reaction fraction within2 min is over 90.00%,and the desorption reaction fraction within 2 min is 72.63%,increasing by 55.36%compared with that of Mg.Mg-16 wt%LaNi has better cyclic stability than that of Mg,only decreasing by 0.609 wt%after 80cycles.The enhancement in thermal storage performances of Mg by adding LaNi is mainly ascribed to the formed Mg_(2)NiH_(4),H_(0.3)Mg_(2)Ni and La_(4)H_(12.19)during the cyclic process which act as catalysts and inhibit the growth of Mg.The above results prove that Mg-16 wt%LaNi is suitable for use as a heat storage material.展开更多
The effect of LaNi and Ti on thermal storage properties of MgH_(2)was investigated.The thermal storage performances of Mg are significantly improved by adding LaNi and Ti.The pressure-composition-temperature(PCT)curve...The effect of LaNi and Ti on thermal storage properties of MgH_(2)was investigated.The thermal storage performances of Mg are significantly improved by adding LaNi and Ti.The pressure-composition-temperature(PCT)curves indicate that the formation enthalpy for Mg-15 wt%Ti-5 wt%LaNi sample is 73.00 kJ·mol^(-1),which approaches to the theoretical values of pure MgH_(2).The isothermal measurement indicates that,for the Mg-15wt%Ti-5 wt%LaNi,the first absorption reaction fraction within 2 min is 93.77%,increasing by 0.32%,0.24%and0.08%compared with those for Mg,Mg-5 wt%LaNi and Mg-15 wt%Ti,respectively.The first desorption reaction fraction within 2 min is 73.18%,increasing by 55.91%,9.79%and 8.12%compared with those for Mg,Mg-5wt%LaNi and Mg-15 wt%Ti,respectively.Moreover,Mg-15 wt%Ti-5 wt%LaNi has the best cyclic stability in all the samples.The thermal storage performances of Mg by adding both LaNi and Ti are improved mainly ascribed to synergistic effect of in situ formed La_(4)H_(12.19),Mg_(2)NiH_(4),H_(0.3)Mg_(2)Ni and TiH_(2)particles during cyclic process.The above analysis demonstrates that Mg-15 wt%Ti-5wt%LaNi is suitable for using as a heat storage material.展开更多
A building model with radiant cooling system was established and the cooling load, indoor temperature, surface temperature of the wails and other parameters in non-cooling and radiant cooling room were calculated by T...A building model with radiant cooling system was established and the cooling load, indoor temperature, surface temperature of the wails and other parameters in non-cooling and radiant cooling room were calculated by TRNSYS. The comparative analysis of the characteristics of attenuation and delay proves that the operation of radiant cooling system increases the degree of temperature attenuation of the room and reduces the inner surface temperature of the wall significantly, but has little effect on the attenuation coefficient and delay time of wall heat transfer. The simulation results also show that the inner surface temperature of the walls in the radiant cooling room is much lower than that in non-cooling room in the day with the maximum cooling load, which reduces the indoor operation temperature largely, and improves the thermal comfort. Finally, according to the analysis of indoor temperature of the rooms with different operation schedules of cooling system, it can be derived that the indoor mean temperature changes with the working time of radiant cooling system, and the operation schedule can be adjusted in practice according to the actual indoor temperature to achieve the integration of energy efficiency and thermal comfort.展开更多
Mullite thermal storage ceramics were prepared by low-cost calcined bauxite and kaolin.The phase composition,microstructure,high temperature resistance and thermophysical properties were characterized by modern testin...Mullite thermal storage ceramics were prepared by low-cost calcined bauxite and kaolin.The phase composition,microstructure,high temperature resistance and thermophysical properties were characterized by modern testing techniques.The experimental results indicate that sample A3(bauxite/kaolin ratio of 5:5)sintered at 1620℃has the optimum comprehensive properties,with bulk density of 2.83 g·cm^(-3)and bending strength of 155.44 MPa.After 30 thermal shocks(1000℃-room temperature,air cooling),the bending strength of sample A3 increases to 166.15 MPa with an enhancement rate of 6.89%,the corresponding thermal conductivity and specific heat capacity are 3.54 W·(m·K)^(-1)and 1.39 kJ·(kg·K)^(-1)at 800℃,and the thermal storage density is 1096 kJ·kg^(-1)(25-800 mullite ceramics;sintering properties;high-temperature thermal storage;thermal shock resistance).Mullite forms a dense and continuous interlaced network microstructure,which endows the samples high thermal storage density and high bending strength,but the decrease of bauxite/kaolin ratio leads to the decrease of mullite content,which reduces the properties of the samples.展开更多
This paper the chilled water and involves the investigations of ice cold thermal storage technologies along with the associated operating strategies for the air conditioning （AC） systems of the typical office buildi...This paper the chilled water and involves the investigations of ice cold thermal storage technologies along with the associated operating strategies for the air conditioning （AC） systems of the typical office buildings in Saudi Arabia, so as to reduce the electricity energy consumption during the peak load periods. In Saudi Arabia, the extensive use of AC for indoor cooling in offices composes a large proportion of the annual peak electricity demand. The very high temperatures over long summer periods, extending tYom May to October, and the low cost of energy are the key factors in the wide and extensive use of air conditioners in the kingdom. This intense cooling load adds up to the requirement increase in the capacity of power plants, which makes them under utilized during the oil：peak periods. Thermal energy storage techniques are one of the effective demand-side energy management methods. Systems with cold storage shifts all or part of the electricity requirement from peak hours to off-peak hours to reduce demand charges and/or take advantage of off-peak rates. The investigations reveal that the cold thermal energy storage techniques are effective from both technical and economic perspectives in the reduction of energy consumption in the buildings during peak periods.展开更多
Ice thermal storage is a promising technology to reduce energy costs by shifting the cooling cost from on-peak to off-peak periods. The paper investigates the application of ice thermal storage and its impact on energ...Ice thermal storage is a promising technology to reduce energy costs by shifting the cooling cost from on-peak to off-peak periods. The paper investigates the application of ice thermal storage and its impact on energy consumption, demand and total energy cost. Energy simulation software along with a chiller model is used to simulate the energy consumption and demand for the existing office building located in central Florida. Furthermore, the study presents a case study to demonstrate the cost saving achieved by the ice storage applications. The results show that although the energy consumption may increase by using ice thermal storage, the energy cost drops significantly, mainly depending on the local utility rate structure. It found that for the investigated system the annual energy consumption increases by about 12% but the annual energy cost drops by about 3 6%.展开更多
To analyze the characteristics of solar seasonal soil thermal storage in a solar-ground coupled heat pump system (SGCHPS) in severe cold area,the software FLUENT was used to establish the three-dimensional unsteady st...To analyze the characteristics of solar seasonal soil thermal storage in a solar-ground coupled heat pump system (SGCHPS) in severe cold area,the software FLUENT was used to establish the three-dimensional unsteady state fluid-solid coupling mathematical model of multi-well ground heat exchanger (MWGHE).The User-Defined Functions (UDF) of solar collector and plate heat exchanger were written and dynamically loaded into the model of MWGHE as the boundary conditions.In this way,the dynamic simulation of solar seasonal soil thermal storage was realized.The comparison of simulative and experimental results showed that the overall variation trend of simulative and experimental values achieves a good agreement with time;the relative errors of simulated parameters are all in the allowable range.Therefore,it can be obtained that the models established can be applied in the investigation of performance of solar seasonal soil thermal storage.At the same time,it provides a theoretical basis for the study of heating in SGCHPS and soil heat balance analysis after long-time thermal storage and extraction.展开更多
In view of the Three North areas existing wind power absorption and environment pollution problems,the previous scholars have improved the wind abandon problem by adding electrothermal coupling equipment or optimizing...In view of the Three North areas existing wind power absorption and environment pollution problems,the previous scholars have improved the wind abandon problem by adding electrothermal coupling equipment or optimizing power grid operation.In this paper,an electrothermal integrated energy system including heat pump and thermal storage units was proposed.The scheduling model was based on the load data and the output characteristics of power units,each power unit capacity was programmed without constraints,and the proposed scheduling model was compared with the traditional combined heat and power scheduling model.Results showed that the investment and pollutant discharge of the system was reduced respectively.Wind power was fully absorbed.Compared with the traditional thermal power unit,the proportion of the output was significantly decreased by the proposed model.The proposed system could provide a new prospect for wind power absorption and environment protection.展开更多
The heat transfer performance of the phase change materials used in free cooling and air conditioning applications is low,due to the poor thermal conductivity of the materials.The recent phenomenal advancement in nano...The heat transfer performance of the phase change materials used in free cooling and air conditioning applications is low,due to the poor thermal conductivity of the materials.The recent phenomenal advancement in nano technology provides an opportunity for an appreciable enhancement in the thermal conductivity of the phase change materials.In order to explore the possibilities of using nano technology for various applications,a detailed parametric study is carried out,to analyse the heat transfer enhancement potential with the thermal conductivity of the conventional phase change materials and nano enhanced phase change materials under various flow conditions of the heat transfer fluid.Initially,the theoretical equation,used to determine the time for outward cylindrical solidification of the phase change material,is validated with the experimental results.It is inferred from the parametric studies,that for paraffinic phase change materials with air as the heat transfer fluid,the first step should be to increase the heat transfer coefficient to the maximum extent,before making any attempt to increase the thermal conductivity of the phase change materials,with the addition of nano particles.When water is used as the phase change material,the addition of nano particles is recommended to achieve better heat transfer,when a liquid is used as the heat transfer fluid.展开更多
Thermal storage has not yet been classified in a unified way.By analyzing the factors of thermal storage and the interactions of fluids,spaces,and solids,this study proposes a three-level classification scheme based o...Thermal storage has not yet been classified in a unified way.By analyzing the factors of thermal storage and the interactions of fluids,spaces,and solids,this study proposes a three-level classification scheme based on fluid-space-solid thermal storage and dissects the main thermal storage types in the Eryuan,Midu,and Lancang areas of Yunnan Province.The results show that the hydrothermal-karst-carbonate reservoirs of the lower Devonian Kanglang Formation,Carboniferous,and Lower Permian are the main reservoirs in the Eryuan area,the hydrothermal-fracture-carbonate reservoirs are Carboniferous and Lower Permian in the Midu area,and the hydrothermal-fracture-metamorphic reservoirs of the Manlai and Huimin formations are the main reservoirs in the Lancang area.These reservoirs are characterized by high porosity and permeability,high thermal conductivity,high thermal diffusivity,and high specific heat capacity.The classification scheme is systematic,comprehensive,and unified,is capable of conveying multiple information points,and provides a new method for geological exploration personnel to analyze the thermal storage characteristics.展开更多
A standard ultramarine pigment was used to produce phase change material composites, by adsorbing n-hexadecane paraffin around the pigment surface with the aim of obtaining a pigment providing thermal storage capacity...A standard ultramarine pigment was used to produce phase change material composites, by adsorbing n-hexadecane paraffin around the pigment surface with the aim of obtaining a pigment providing thermal storage capacity apart from color. Vacuum impregnation method was employed optimizing the process variables to maximize the latent heat of the hexadecane/pigment composite. In addition to the process optimization, the stability of the composite having the maximum latent heat was investigated. The hexadecane/pigment composite providing the highest latent heat has a Latent heat of fusion of 44 J/g (around a 20%wt. hexadecane adsorbed in the pigment). Durability of the material was tested by thermo-diffractometric measurements. The results indicate slow reduction of the area intensity up to 6.5% after the 100 cycles.展开更多
In this article, a new kind of solar fresh air system is designed in order to realize the improvement of thermal efficiency by the integrated application of the PCMs and heat pipe technology. Under the adequate sunshi...In this article, a new kind of solar fresh air system is designed in order to realize the improvement of thermal efficiency by the integrated application of the PCMs and heat pipe technology. Under the adequate sunshine condition, the fresh air is directly delivered into the indoor environment after being heated by the solar collector. When the sun radiation is reduced, the heated air temperature can not satisfy the need of supply of air temperature.The main heat source is changed to phase change heat storage equipment instead of solar energy. The system adopt heat pipe for a high-efficiency and isothermal heat transfer which recover the shortcomings of PCMs such as： low coefficient of thermal conductivity and poor thermal efficiency. This article establishes the physical model of phase change solar energy fresh air thermal storage system and creates the mathematical model of its unsteady heat transfer to simulate and analyse the operation process by using Fluent software. The results of the study show that, compared to normal fresh air system, the phase change solar energy fresh air thermal storage system has a significant improvement in energy saving and indoor comfort level and will play an important role in the energy sustainable development.展开更多
At present, the main heating method for reducing crude oil viscosity is electric heating, and the all-day electric heating method has the problems of high energy consumption and high cost. In order to meet the needs o...At present, the main heating method for reducing crude oil viscosity is electric heating, and the all-day electric heating method has the problems of high energy consumption and high cost. In order to meet the needs of environmental protection and industrial production, a new type of phase change thermal storage electric heating device was designed by combining the crude oil viscosity reduction heating method with valley price and phase change materials. The results indicate that as the inlet flow rate of the working fluid increases, the outlet temperature continuously decreases. And when the outlet temperature rises to 10?C, the inlet flow rate of the device can meet the flow range of 1.413 - 2.120 m3/h. At the same time, the addition of foam nickel makes the internal temperature of PCM more uniform, and the internal temperature of PCM decreases with the decrease of porosity of foam metal. By increasing the number of electric heating rods and reducing the power of individual electric heating rods, the structure of the device was optimized to significantly improve local high-temperature phenomena. The use of this device can maintain high heat exchange efficiency and reduce production costs.展开更多
In order to improve the thermal storage capacity of expanded vermiculite（EV） based formstable composite PCM（FS-PCM） via organic modification of EV, first, EV was modified with a sodium stearate（Na St） as surface...In order to improve the thermal storage capacity of expanded vermiculite（EV） based formstable composite PCM（FS-PCM） via organic modification of EV, first, EV was modified with a sodium stearate（Na St） as surface modifier, and organic EV（OEV） with hydrophobicity and higher adsorption capacity for fatty acid was obtained. A novel capric-stearic acid eutectic（CA-SA）/OEV FS-PCM with high thermal storage capacity was then developed. OEV and CA-SA/OEV were characterized by scanning electron microscopy（SEM）, X-ray diffraction（XRD）, Fourier transform infrared spectroscopy（FTIR）, differential scanning calorimetry（DSC）, thermal gravimetry（TG）, and thermal cycling test. Results showed that OEV has obvious hydrophobicity and a higher adsorption capacity for fatty acid. Its adsorption ratio has increased by 48.71% compared with that of EV. CA-SA/OEV possesses high thermal storage density（112.52 J/g）, suitable melting temperature（20.49 ℃）, good chemical compatibility, excellent thermal stability and reliability, indicating great application potential for building energy efficiency. Moreover, organic modification of inorganic matrix may offer novel options for improving its adsorption capacity for organic PCMs and increasing heat storage capacity of corresponding FS-PCMs.展开更多
文摘In order to address the synergistic optimization of energy efficiency improvement in the waste incineration power plant(WIPP)and renewable energy accommodation,an electricity-hydrogen-waste multi-energy system integrated with phase change material(PCM)thermal storage is proposed.First,a thermal energy management framework is constructed,combining PCM thermal storage with the alkaline electrolyzer(AE)waste heat recovery and the heat pump(HP),while establishing a PCM-driven waste drying system to enhance the efficiency of waste incineration power generation.Next,a flue gas treatment method based on purification-separation-storage coordination is adopted,achieving spatiotemporal decoupling between waste incineration and flue gas treatment.Subsequently,a two-stage optimal dispatching strategy for the multi-energy system is developed:the first stage establishes a dayahead economic dispatch model with the objective of minimizing net system costs,while the second stage introduces model predictive control(MPC)to realize intraday rolling optimization.Finally,The optimal dispatching strategies under different scenarios are obtained using the Gurobi solver,followed by a comparative analysis of the optimized operational outcomes.Simulation results demonstrate that the proposed system optimizes the output and operational states of each unit,simultaneously reducing carbon trading costs while increasing electricity sales revenue.The proposed scheduling strategy demonstrates effective grid peak-shaving functionality,thereby simultaneously improving the system’s economic performance and operational flexibility while providing an innovative technical pathway for municipal solid waste(MSW)resource utilization and low-carbon transformation of energy systems.
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.
基金supported by the National Natural Science Foundation of China(Grant No.51976092)。
文摘High-temperature phase change materials(PCMs)have attracted significant attention in the field of thermal energy storage due to their ability to store and release large amounts of heat within a small temperature fluctuation range.However,their practical application is limited due to problems such as leakage,corrosion,and volume changes at high temperatures.Recent research has shown that macroencapsulation technology holds promise in addressing these issues.This paper focuses on the macroencapsulation technology of high-temperature PCMs,starting with a review of the classification and development history of high-temperature macroencapsulatd PCMs.Four major encapsulation strategies,including electroplating method,solid/liquid filling method,sacrificial material method,and powder compaction into sphere method,are then summarized.The methods for effectively addressing issues such as corrosion,leakage,supercooling,and phase separation in PCMs are analyzed,along with approaches for improving the heat transfer performance,mechanical strength,and thermal cycling stability of macrocapsules.Subsequently,the structure and packing arrangement optimization of macrocapsules in thermal storage systems is discussed in detail.Finally,after comparing the performance of various encapsulation strategies and summarizing existing issues,the current technical challenges,improvement methods,and future development directions are proposed.More attention should be given to utilizing AI technology and reinforcement learning to reveal the multiphysics-coupled heat and mass transfer mechanisms in macrocapsule applications,as well as to optimize material selection and encapsulation parameters,thereby enhancing the overall efficiency of thermal storage systems.
基金National Natural Science Foundation of China (50276001, 50876004)
文摘This article,based on authors＇ long-term study,proposes an improved foamed-Ni-packed phase-change thermal storage canister,which takes advantage of the foamed-Ni characteristic of instinctive porous structure and excellent properties to ameliorate its void distribution and thermal conductivity. The improved canister and the unimproved one without foamed-Ni package,are put to heat absorbing and releasing tests to investigate the effects of heat absorbing temperature upon the phase-change materials （PCM） melting time under three temperature schemes by using platinum resistance thermometers （PT100） and data acquisition modules （ADAM-4000） to gather the data of varying temperature. Afterwards,the computerized tomography （CT） is employed to scan the void distribution in both canisters. Compared to the unimproved canister,the experimental results evidence the superiority of the improved one in higher uniformity in void and temperature distribution as well as faster thermal responses.
基金financially supported by the National Natural Science Foundation of China(No.51902025).
文摘Rapid advances in thermal management technology and the increasing need for multi-energy conversion have placed stringent energy efficiency requirements on next-generation shape-stable composite phase change materials(PCMs).Magnetically-responsive phase change thermal storage materials are considered an emerging concept for energy storage systems,enabling PCMs to perform unprecedented functions(such as green energy utilization,magnetic thermotherapy,drug release,etc.).The combination of multifunctional magnetic nanomaterials and PCMs is a milestone in the creation of advanced multifunctional composite PCMs.However,a timely and comprehensive review of composite PCMs based on magnetic nanoparticle modification is still missing.Herein,we furnish an exhaustive exposition elucidating the cutting-edge advancements in magnetically responsive composite PCMs.We delve deeply into the multifarious roles assumed by distinct nanoparticles within composite PCMs of varying dimensions,meticulously scrutinizing the intricate interplay between their architectures and thermophysical attributes.Moreover,we prognosticate future research trajectories,delineate alternative stratagems,and illuminate prospective avenues.This review is intended to stimulate broader academic interest in interdisciplinary fields and provide valuable insights into the development of next-generation magnetically-responsive composite PCMs.
基金Funded by the Major State Basic Research Development Program of China(973 Program)(No.2010CB227105)
文摘For improving the properties of SiC-mullite composite ceramics used for solar sensible thermal storage, MnO2 was introduced as sintering additive when preparing. The composite ceramics were synthesized by using SiC, andalusite, a-Al2O3 as the starting materials with non-contact graphite-buried sintering method. Phase composition and microstructure of the composites were investigated by XRD and SEM, and the effect of MnOz on the properties of SiC composites was studied. Results indicated that samples SM1 with 0.2 wt% MnO2 addition achieved the optimum properties： bending strength of 70.96 MPa, heat capacity of 1.02 J.（g.K）-1, thermal conductivity of 9.05 W-（m.K）-1. Proper addition of MnO2 was found to weaken the volume effect of the composites and improve the thermal shock resistance with an increased rate of 27.84% for bending strength after 30 cycles of thermal shock （air cooling from 1 100 ℃ to RT）. Key words： SiC-mullite composite ceramics; MnO2; solar sensible thermal storage; non-contact graphite-buried sintering; thermal shock resistance
基金financially supported by the Beijing Municipal Commission of Science and Technology of China(No.D141100002014001)。
文摘The effect of LaNi on thermal storage properties of MgH2 prepared by ball milling under hydrogen atmosphere was investigated.The thermal storage properties,cyclic property and thermal storage mechanism were studied by pres sure-composition-temperature(PC T),X-ray diffraction(XRD)and transmission electron microscopy(TEM).The Van't Hoff curve indicates that the formation enthalpy of Mg-16 wt%LaNi is 74.62 kJ·mol^(-1),which approaches to the theoretical values of MgH2.The isothermal measurement indicates that Mg-16 wt%LaNi can absorb 6.263 wt%H_(2)within 30 min at 390℃for the first absorption,the absorption reaction fraction within2 min is over 90.00%,and the desorption reaction fraction within 2 min is 72.63%,increasing by 55.36%compared with that of Mg.Mg-16 wt%LaNi has better cyclic stability than that of Mg,only decreasing by 0.609 wt%after 80cycles.The enhancement in thermal storage performances of Mg by adding LaNi is mainly ascribed to the formed Mg_(2)NiH_(4),H_(0.3)Mg_(2)Ni and La_(4)H_(12.19)during the cyclic process which act as catalysts and inhibit the growth of Mg.The above results prove that Mg-16 wt%LaNi is suitable for use as a heat storage material.
基金financially supported by the Beijing Municipal Commission of Science and Technology of China(D141100002014001)。
文摘The effect of LaNi and Ti on thermal storage properties of MgH_(2)was investigated.The thermal storage performances of Mg are significantly improved by adding LaNi and Ti.The pressure-composition-temperature(PCT)curves indicate that the formation enthalpy for Mg-15 wt%Ti-5 wt%LaNi sample is 73.00 kJ·mol^(-1),which approaches to the theoretical values of pure MgH_(2).The isothermal measurement indicates that,for the Mg-15wt%Ti-5 wt%LaNi,the first absorption reaction fraction within 2 min is 93.77%,increasing by 0.32%,0.24%and0.08%compared with those for Mg,Mg-5 wt%LaNi and Mg-15 wt%Ti,respectively.The first desorption reaction fraction within 2 min is 73.18%,increasing by 55.91%,9.79%and 8.12%compared with those for Mg,Mg-5wt%LaNi and Mg-15 wt%Ti,respectively.Moreover,Mg-15 wt%Ti-5 wt%LaNi has the best cyclic stability in all the samples.The thermal storage performances of Mg by adding both LaNi and Ti are improved mainly ascribed to synergistic effect of in situ formed La_(4)H_(12.19),Mg_(2)NiH_(4),H_(0.3)Mg_(2)Ni and TiH_(2)particles during cyclic process.The above analysis demonstrates that Mg-15 wt%Ti-5wt%LaNi is suitable for using as a heat storage material.
基金Project(2010DFA72740) supported by the International Science & Technology Cooperation Program of China
文摘A building model with radiant cooling system was established and the cooling load, indoor temperature, surface temperature of the wails and other parameters in non-cooling and radiant cooling room were calculated by TRNSYS. The comparative analysis of the characteristics of attenuation and delay proves that the operation of radiant cooling system increases the degree of temperature attenuation of the room and reduces the inner surface temperature of the wall significantly, but has little effect on the attenuation coefficient and delay time of wall heat transfer. The simulation results also show that the inner surface temperature of the walls in the radiant cooling room is much lower than that in non-cooling room in the day with the maximum cooling load, which reduces the indoor operation temperature largely, and improves the thermal comfort. Finally, according to the analysis of indoor temperature of the rooms with different operation schedules of cooling system, it can be derived that the indoor mean temperature changes with the working time of radiant cooling system, and the operation schedule can be adjusted in practice according to the actual indoor temperature to achieve the integration of energy efficiency and thermal comfort.
基金Funded by the National Key Research and Development Program of Science and Technology of China(No.2018YFB1501002)。
文摘Mullite thermal storage ceramics were prepared by low-cost calcined bauxite and kaolin.The phase composition,microstructure,high temperature resistance and thermophysical properties were characterized by modern testing techniques.The experimental results indicate that sample A3(bauxite/kaolin ratio of 5:5)sintered at 1620℃has the optimum comprehensive properties,with bulk density of 2.83 g·cm^(-3)and bending strength of 155.44 MPa.After 30 thermal shocks(1000℃-room temperature,air cooling),the bending strength of sample A3 increases to 166.15 MPa with an enhancement rate of 6.89%,the corresponding thermal conductivity and specific heat capacity are 3.54 W·(m·K)^(-1)and 1.39 kJ·(kg·K)^(-1)at 800℃,and the thermal storage density is 1096 kJ·kg^(-1)(25-800 mullite ceramics;sintering properties;high-temperature thermal storage;thermal shock resistance).Mullite forms a dense and continuous interlaced network microstructure,which endows the samples high thermal storage density and high bending strength,but the decrease of bauxite/kaolin ratio leads to the decrease of mullite content,which reduces the properties of the samples.
文摘This paper the chilled water and involves the investigations of ice cold thermal storage technologies along with the associated operating strategies for the air conditioning （AC） systems of the typical office buildings in Saudi Arabia, so as to reduce the electricity energy consumption during the peak load periods. In Saudi Arabia, the extensive use of AC for indoor cooling in offices composes a large proportion of the annual peak electricity demand. The very high temperatures over long summer periods, extending tYom May to October, and the low cost of energy are the key factors in the wide and extensive use of air conditioners in the kingdom. This intense cooling load adds up to the requirement increase in the capacity of power plants, which makes them under utilized during the oil：peak periods. Thermal energy storage techniques are one of the effective demand-side energy management methods. Systems with cold storage shifts all or part of the electricity requirement from peak hours to off-peak hours to reduce demand charges and/or take advantage of off-peak rates. The investigations reveal that the cold thermal energy storage techniques are effective from both technical and economic perspectives in the reduction of energy consumption in the buildings during peak periods.
文摘Ice thermal storage is a promising technology to reduce energy costs by shifting the cooling cost from on-peak to off-peak periods. The paper investigates the application of ice thermal storage and its impact on energy consumption, demand and total energy cost. Energy simulation software along with a chiller model is used to simulate the energy consumption and demand for the existing office building located in central Florida. Furthermore, the study presents a case study to demonstrate the cost saving achieved by the ice storage applications. The results show that although the energy consumption may increase by using ice thermal storage, the energy cost drops significantly, mainly depending on the local utility rate structure. It found that for the investigated system the annual energy consumption increases by about 12% but the annual energy cost drops by about 3 6%.
基金Sponsored by the Scienctific and Technology Project of Heilongjiang Province(Grant No.2007-04)
文摘To analyze the characteristics of solar seasonal soil thermal storage in a solar-ground coupled heat pump system (SGCHPS) in severe cold area,the software FLUENT was used to establish the three-dimensional unsteady state fluid-solid coupling mathematical model of multi-well ground heat exchanger (MWGHE).The User-Defined Functions (UDF) of solar collector and plate heat exchanger were written and dynamically loaded into the model of MWGHE as the boundary conditions.In this way,the dynamic simulation of solar seasonal soil thermal storage was realized.The comparison of simulative and experimental results showed that the overall variation trend of simulative and experimental values achieves a good agreement with time;the relative errors of simulated parameters are all in the allowable range.Therefore,it can be obtained that the models established can be applied in the investigation of performance of solar seasonal soil thermal storage.At the same time,it provides a theoretical basis for the study of heating in SGCHPS and soil heat balance analysis after long-time thermal storage and extraction.
基金the fund program of research on re-electrification(heat pump clean heating)to promote the new energy consumption in Shaanxi power grid(5226KY18002P).
文摘In view of the Three North areas existing wind power absorption and environment pollution problems,the previous scholars have improved the wind abandon problem by adding electrothermal coupling equipment or optimizing power grid operation.In this paper,an electrothermal integrated energy system including heat pump and thermal storage units was proposed.The scheduling model was based on the load data and the output characteristics of power units,each power unit capacity was programmed without constraints,and the proposed scheduling model was compared with the traditional combined heat and power scheduling model.Results showed that the investment and pollutant discharge of the system was reduced respectively.Wind power was fully absorbed.Compared with the traditional thermal power unit,the proportion of the output was significantly decreased by the proposed model.The proposed system could provide a new prospect for wind power absorption and environment protection.
文摘The heat transfer performance of the phase change materials used in free cooling and air conditioning applications is low,due to the poor thermal conductivity of the materials.The recent phenomenal advancement in nano technology provides an opportunity for an appreciable enhancement in the thermal conductivity of the phase change materials.In order to explore the possibilities of using nano technology for various applications,a detailed parametric study is carried out,to analyse the heat transfer enhancement potential with the thermal conductivity of the conventional phase change materials and nano enhanced phase change materials under various flow conditions of the heat transfer fluid.Initially,the theoretical equation,used to determine the time for outward cylindrical solidification of the phase change material,is validated with the experimental results.It is inferred from the parametric studies,that for paraffinic phase change materials with air as the heat transfer fluid,the first step should be to increase the heat transfer coefficient to the maximum extent,before making any attempt to increase the thermal conductivity of the phase change materials,with the addition of nano particles.When water is used as the phase change material,the addition of nano particles is recommended to achieve better heat transfer,when a liquid is used as the heat transfer fluid.
文摘Thermal storage has not yet been classified in a unified way.By analyzing the factors of thermal storage and the interactions of fluids,spaces,and solids,this study proposes a three-level classification scheme based on fluid-space-solid thermal storage and dissects the main thermal storage types in the Eryuan,Midu,and Lancang areas of Yunnan Province.The results show that the hydrothermal-karst-carbonate reservoirs of the lower Devonian Kanglang Formation,Carboniferous,and Lower Permian are the main reservoirs in the Eryuan area,the hydrothermal-fracture-carbonate reservoirs are Carboniferous and Lower Permian in the Midu area,and the hydrothermal-fracture-metamorphic reservoirs of the Manlai and Huimin formations are the main reservoirs in the Lancang area.These reservoirs are characterized by high porosity and permeability,high thermal conductivity,high thermal diffusivity,and high specific heat capacity.The classification scheme is systematic,comprehensive,and unified,is capable of conveying multiple information points,and provides a new method for geological exploration personnel to analyze the thermal storage characteristics.
基金founding from the European Union Seventh Framework Programme(FP7-NMP-2010-Small-5)under grant agreement n°280393from the Dpto.Educacion,Politica Linguistica y Cultura of the Basque Goverment(IT-630-13),Ministerio de Ciencia e Innovacion(MAT2013-42092-R)Engineering and Physical Sciences Research Council(EP/I003932).
文摘A standard ultramarine pigment was used to produce phase change material composites, by adsorbing n-hexadecane paraffin around the pigment surface with the aim of obtaining a pigment providing thermal storage capacity apart from color. Vacuum impregnation method was employed optimizing the process variables to maximize the latent heat of the hexadecane/pigment composite. In addition to the process optimization, the stability of the composite having the maximum latent heat was investigated. The hexadecane/pigment composite providing the highest latent heat has a Latent heat of fusion of 44 J/g (around a 20%wt. hexadecane adsorbed in the pigment). Durability of the material was tested by thermo-diffractometric measurements. The results indicate slow reduction of the area intensity up to 6.5% after the 100 cycles.
文摘In this article, a new kind of solar fresh air system is designed in order to realize the improvement of thermal efficiency by the integrated application of the PCMs and heat pipe technology. Under the adequate sunshine condition, the fresh air is directly delivered into the indoor environment after being heated by the solar collector. When the sun radiation is reduced, the heated air temperature can not satisfy the need of supply of air temperature.The main heat source is changed to phase change heat storage equipment instead of solar energy. The system adopt heat pipe for a high-efficiency and isothermal heat transfer which recover the shortcomings of PCMs such as： low coefficient of thermal conductivity and poor thermal efficiency. This article establishes the physical model of phase change solar energy fresh air thermal storage system and creates the mathematical model of its unsteady heat transfer to simulate and analyse the operation process by using Fluent software. The results of the study show that, compared to normal fresh air system, the phase change solar energy fresh air thermal storage system has a significant improvement in energy saving and indoor comfort level and will play an important role in the energy sustainable development.
文摘At present, the main heating method for reducing crude oil viscosity is electric heating, and the all-day electric heating method has the problems of high energy consumption and high cost. In order to meet the needs of environmental protection and industrial production, a new type of phase change thermal storage electric heating device was designed by combining the crude oil viscosity reduction heating method with valley price and phase change materials. The results indicate that as the inlet flow rate of the working fluid increases, the outlet temperature continuously decreases. And when the outlet temperature rises to 10?C, the inlet flow rate of the device can meet the flow range of 1.413 - 2.120 m3/h. At the same time, the addition of foam nickel makes the internal temperature of PCM more uniform, and the internal temperature of PCM decreases with the decrease of porosity of foam metal. By increasing the number of electric heating rods and reducing the power of individual electric heating rods, the structure of the device was optimized to significantly improve local high-temperature phenomena. The use of this device can maintain high heat exchange efficiency and reduce production costs.
基金Funded by the Major State Research Development Program of China during the 13th Five-Year Plan Period(No.2016YFC0700904)the Science and Technology Support Program of Hubei Province(Nos.2014BAA134 and 2015BAA107)
文摘In order to improve the thermal storage capacity of expanded vermiculite（EV） based formstable composite PCM（FS-PCM） via organic modification of EV, first, EV was modified with a sodium stearate（Na St） as surface modifier, and organic EV（OEV） with hydrophobicity and higher adsorption capacity for fatty acid was obtained. A novel capric-stearic acid eutectic（CA-SA）/OEV FS-PCM with high thermal storage capacity was then developed. OEV and CA-SA/OEV were characterized by scanning electron microscopy（SEM）, X-ray diffraction（XRD）, Fourier transform infrared spectroscopy（FTIR）, differential scanning calorimetry（DSC）, thermal gravimetry（TG）, and thermal cycling test. Results showed that OEV has obvious hydrophobicity and a higher adsorption capacity for fatty acid. Its adsorption ratio has increased by 48.71% compared with that of EV. CA-SA/OEV possesses high thermal storage density（112.52 J/g）, suitable melting temperature（20.49 ℃）, good chemical compatibility, excellent thermal stability and reliability, indicating great application potential for building energy efficiency. Moreover, organic modification of inorganic matrix may offer novel options for improving its adsorption capacity for organic PCMs and increasing heat storage capacity of corresponding FS-PCMs.
