To effectively enhance the energy utilisation rate of the park integrated energy system(PIES),and to strengthen the stability and reliability of PIES power supply,geothermal heat pumps and thermal/cool storage devices...To effectively enhance the energy utilisation rate of the park integrated energy system(PIES),and to strengthen the stability and reliability of PIES power supply,geothermal heat pumps and thermal/cool storage devices are introduced.An optimisation scheduling method for PIES based on maximum power point tracking(MPPT)and mixed integer linear programming is proposed.Firstly,taking into account the fluctuating and unpredictable nature of wind and solar power generation,the tip speed ratio(TSR)and incremental conductance(IncCond)methods are applied for MPPT of wind and solar power output.Secondly,geothermal heat pumps and thermal/cool storage devices are integrated into PIES to construct a typical daily multienergy flow coupled optimisation scheduling model.Lastly,the overall operational expenses and ecological impacts of PIES are comprehensively considered for an economic and environmental comparison analysis.Case study results verify that the introduction of geothermal heat pumps and thermal/cool storage devices enhances the energy efficiency and bolsters the overall economic and ecological effectiveness of PIES.展开更多
This work investigates the transient behaviour of a phase change material based cool thermal energy storage (CTES) system comprised of a cylindrical storage tank filled with encapsulated phase change materials (PCMs) ...This work investigates the transient behaviour of a phase change material based cool thermal energy storage (CTES) system comprised of a cylindrical storage tank filled with encapsulated phase change materials (PCMs) in spherical container integrated with an ethylene glycol chiller plant. A simulation program was developed to evaluate the temperature histories of the heat transfer fluid (HTF) and the phase change material at any axial location during the charging period. The results of the model were validated by comparison with experimental results of temperature profiles of HTF and PCM. The model was also used to investigate the effect of porosity, Stanton number, Stefan number and Peclet number on CTES system performance. The results showed that increase in porosity contributes to a higher rate of energy storage. However, for a given geometry and heat transfer coefficient, the mass of PCM charged in the unit decreases as the increase in porosity. The St number as well as the Ste number is also influential in the performance of the unit. The model is a convenient and more suitable method to determine the heat transfer characteristics of CTES system. The results reported are much useful for designing CTES system.展开更多
In this study,the influence of the phase-change cooling storage system on integrating and controlling of the combined cooling,heating,and power system was analyzed through experiments and computational fluid dynamics ...In this study,the influence of the phase-change cooling storage system on integrating and controlling of the combined cooling,heating,and power system was analyzed through experiments and computational fluid dynamics simulations.The model of three-dimensional phase change material plate and cold storage tank was established and verified.The phase change material selected in this study is a eutectic salt with a phase change temperature of 8℃.The thermodynamic performance of the cold storage tank filled with phase change material plates was calculated,and the energy storage and release efficiency of the phase-change cooling storage system was analyzed.The results indicate that the phase change process correlates positively with the heat transfer fluid flow rate.The heat transfer fluid flow rates of 1.2 m^(3)/h,1.6 m^(3)/h,and 2.0 m^(3)/h all allow the phase change material within the encapsulation module to completely solidify within 8 hours;the flow rate required for melting is not less than 2.0 m^(3)/h,and the highest energy storage efficiency is up to 72%.Considering the thermodynamic performance of the phase-change cooling storage system,it is recommended to use a heat transfer fluid flow rate of 1.6 m^(3)/h for the cooling charge process and 2.0 m^(3)/h for the cooling release process.展开更多
The Photovoltaic Energy storage Direct current and Flexibility(PEDF)system has attracted significant attention in recent years.In this system,charging piles,air conditioning,building energy storage,and photovoltaic ar...The Photovoltaic Energy storage Direct current and Flexibility(PEDF)system has attracted significant attention in recent years.In this system,charging piles,air conditioning,building energy storage,and photovoltaic are connected to the direct current bus,with flexible adjustment capabilities.The increasing presence of flexible loads complicates the calculation of electrical balance in buildings.Building energy storage is a crucial component of the PEDF system,and its storage capacity(kWh)and power(kW)are parameters that need to be determined during the design phase.This study focuses on the energy storage system of PEDF,considering both electricity and cooling storage methods,with the goal of optimizing capacity and power for economy.A dual-layer optimization model of“operational-design optimization”is proposed.The operational optimization model enables the calculation of power supply and demand balance involving multiple flexible loads over the entire year of 8760 hours.In the design optimization model,equipment investment is considered based on the operational optimization model,and particle swarm optimization(PSO)is employed to achieve the design optimization of energy storage system.This study uses a Shenzhen office building as a case study,demonstrating that the installation of battery and cooling storage facility can enhance system economic efficiency,while the scale of photovoltaic installation and time-of-use tariff significantly impact the design of building energy storage solutions.展开更多
Laser cooling of Li-like C^3＋and O^4＋relativistic heavy ion beams is planned at the experimental Cooler Storage Ring（CSRe）. Recently, a preparatory experiment to test important prerequisites for laser cooling of r...Laser cooling of Li-like C^3＋and O^4＋relativistic heavy ion beams is planned at the experimental Cooler Storage Ring（CSRe）. Recently, a preparatory experiment to test important prerequisites for laser cooling of relativistic^12C^3＋ion beams using a pulsed laser system has been performed at the CSRe. Unfortunately, the interaction between the ions and the pulsed laser cannot be detected. In order to study the laser cooling process and find the optimized parameters for future laser cooling experiments, a multi-particle tracking method has been developed to simulate the detailed longitudinal dynamics of laser-cooled ion beams at the CSRe. Simulations of laser cooling of the^12C^3＋ion beams by scanning the frequency of the RF-buncher or continuous wave（CW） laser wavelength have been performed. The simulation results indicate that ion beams with a large momentum spread could be laser-cooled by the combination of only one CW laser and the RF-buncher, and show the requirements of a successful laser cooling experiment. The optimized parameters for scanning the RF-buncher frequency or laser frequency have been obtained.Furthermore, the heating effects have been estimated for laser cooling at the CSRe. The Schottky noise spectra of longitudinally modulated and laser-cooled ion beams have been simulated to fully explain and anticipate the experimental results. The combination of Schottky spectra from the highly sensitive resonant Schottky pick-up and the simulation methods developed in this paper will be helpful to investigate the longitudinal dynamics of RF-bunched and ultra-cold ion beams in the upcoming laser cooling experiments at the CSRe.展开更多
基金supported by Liaoning Revitalization Talents ProgramXLYC2008005.
文摘To effectively enhance the energy utilisation rate of the park integrated energy system(PIES),and to strengthen the stability and reliability of PIES power supply,geothermal heat pumps and thermal/cool storage devices are introduced.An optimisation scheduling method for PIES based on maximum power point tracking(MPPT)and mixed integer linear programming is proposed.Firstly,taking into account the fluctuating and unpredictable nature of wind and solar power generation,the tip speed ratio(TSR)and incremental conductance(IncCond)methods are applied for MPPT of wind and solar power output.Secondly,geothermal heat pumps and thermal/cool storage devices are integrated into PIES to construct a typical daily multienergy flow coupled optimisation scheduling model.Lastly,the overall operational expenses and ecological impacts of PIES are comprehensively considered for an economic and environmental comparison analysis.Case study results verify that the introduction of geothermal heat pumps and thermal/cool storage devices enhances the energy efficiency and bolsters the overall economic and ecological effectiveness of PIES.
文摘This work investigates the transient behaviour of a phase change material based cool thermal energy storage (CTES) system comprised of a cylindrical storage tank filled with encapsulated phase change materials (PCMs) in spherical container integrated with an ethylene glycol chiller plant. A simulation program was developed to evaluate the temperature histories of the heat transfer fluid (HTF) and the phase change material at any axial location during the charging period. The results of the model were validated by comparison with experimental results of temperature profiles of HTF and PCM. The model was also used to investigate the effect of porosity, Stanton number, Stefan number and Peclet number on CTES system performance. The results showed that increase in porosity contributes to a higher rate of energy storage. However, for a given geometry and heat transfer coefficient, the mass of PCM charged in the unit decreases as the increase in porosity. The St number as well as the Ste number is also influential in the performance of the unit. The model is a convenient and more suitable method to determine the heat transfer characteristics of CTES system. The results reported are much useful for designing CTES system.
基金supported by the National Key Research and Development Program of China (Grant No.2023YFB4204000)National Key Research and Development Program of China (Grant No.2024YFB4206500)。
文摘In this study,the influence of the phase-change cooling storage system on integrating and controlling of the combined cooling,heating,and power system was analyzed through experiments and computational fluid dynamics simulations.The model of three-dimensional phase change material plate and cold storage tank was established and verified.The phase change material selected in this study is a eutectic salt with a phase change temperature of 8℃.The thermodynamic performance of the cold storage tank filled with phase change material plates was calculated,and the energy storage and release efficiency of the phase-change cooling storage system was analyzed.The results indicate that the phase change process correlates positively with the heat transfer fluid flow rate.The heat transfer fluid flow rates of 1.2 m^(3)/h,1.6 m^(3)/h,and 2.0 m^(3)/h all allow the phase change material within the encapsulation module to completely solidify within 8 hours;the flow rate required for melting is not less than 2.0 m^(3)/h,and the highest energy storage efficiency is up to 72%.Considering the thermodynamic performance of the phase-change cooling storage system,it is recommended to use a heat transfer fluid flow rate of 1.6 m^(3)/h for the cooling charge process and 2.0 m^(3)/h for the cooling release process.
基金supported by the National Key Research and Development Program of China(2023YFC3807002)。
文摘The Photovoltaic Energy storage Direct current and Flexibility(PEDF)system has attracted significant attention in recent years.In this system,charging piles,air conditioning,building energy storage,and photovoltaic are connected to the direct current bus,with flexible adjustment capabilities.The increasing presence of flexible loads complicates the calculation of electrical balance in buildings.Building energy storage is a crucial component of the PEDF system,and its storage capacity(kWh)and power(kW)are parameters that need to be determined during the design phase.This study focuses on the energy storage system of PEDF,considering both electricity and cooling storage methods,with the goal of optimizing capacity and power for economy.A dual-layer optimization model of“operational-design optimization”is proposed.The operational optimization model enables the calculation of power supply and demand balance involving multiple flexible loads over the entire year of 8760 hours.In the design optimization model,equipment investment is considered based on the operational optimization model,and particle swarm optimization(PSO)is employed to achieve the design optimization of energy storage system.This study uses a Shenzhen office building as a case study,demonstrating that the installation of battery and cooling storage facility can enhance system economic efficiency,while the scale of photovoltaic installation and time-of-use tariff significantly impact the design of building energy storage solutions.
基金Supported by National Natural Science Foundation of China(11405237,11504388)
文摘Laser cooling of Li-like C^3＋and O^4＋relativistic heavy ion beams is planned at the experimental Cooler Storage Ring（CSRe）. Recently, a preparatory experiment to test important prerequisites for laser cooling of relativistic^12C^3＋ion beams using a pulsed laser system has been performed at the CSRe. Unfortunately, the interaction between the ions and the pulsed laser cannot be detected. In order to study the laser cooling process and find the optimized parameters for future laser cooling experiments, a multi-particle tracking method has been developed to simulate the detailed longitudinal dynamics of laser-cooled ion beams at the CSRe. Simulations of laser cooling of the^12C^3＋ion beams by scanning the frequency of the RF-buncher or continuous wave（CW） laser wavelength have been performed. The simulation results indicate that ion beams with a large momentum spread could be laser-cooled by the combination of only one CW laser and the RF-buncher, and show the requirements of a successful laser cooling experiment. The optimized parameters for scanning the RF-buncher frequency or laser frequency have been obtained.Furthermore, the heating effects have been estimated for laser cooling at the CSRe. The Schottky noise spectra of longitudinally modulated and laser-cooled ion beams have been simulated to fully explain and anticipate the experimental results. The combination of Schottky spectra from the highly sensitive resonant Schottky pick-up and the simulation methods developed in this paper will be helpful to investigate the longitudinal dynamics of RF-bunched and ultra-cold ion beams in the upcoming laser cooling experiments at the CSRe.
