The paper gives a thorough survey of the studies of different authors in the field of domestic hot water (DHW) consumption and consumption profiles. It presents an overview of the research done into DHW by the Tallinn...The paper gives a thorough survey of the studies of different authors in the field of domestic hot water (DHW) consumption and consumption profiles. It presents an overview of the research done into DHW by the Tallinn University of Technology. Working out on the basis of investigations has been new empirical formulas for determining design flow rates for schools, kindergartens, office buildings and shopping centres. DHW consumption profiles of typical buildings are presented. Comparisons are given on the determination of DHW design flow rates by the standard EVS 835, the EN 806-3 and the recommended formulas. The latter makes it possible to considerably decrease the design flow rates which in turn enables to deminish the load of the equipment, to improve the quality of control and to decrease the diameters of the pipes of the district heating network and the losses of heat in them.展开更多
Worldwide,there are many options to ensure domestic hot water(DHW)provision in dwellings.This study aimed to depict the distribution of energy sources and DHW production systems in the Calabria region.The research was...Worldwide,there are many options to ensure domestic hot water(DHW)provision in dwellings.This study aimed to depict the distribution of energy sources and DHW production systems in the Calabria region.The research was focused on understanding which variables,among contextual variables and building characteristics,may influence the adoption of a particular energy source or production system.Descriptive statistics and chi-square test of independence have been developed.Significant relationships were found between the climatic zone and the energy source used as well as between the climatic zone and the production system installed in both households with a separated and a combined DHW production system.Furthermore,the population of the municipality and the dwelling type resulted to be significant variables for the preference of an energy source or the diffusion of a combined production system.展开更多
珊瑚礁白化是由于珊瑚失去体内共生的虫黄藻或者共生的虫黄藻失去体内色素而导致五彩缤纷的珊瑚礁变白的现象,严重的白化可以带来珊瑚礁的死亡。国内外研究表明海水温度升高和珊瑚礁白化关系最为紧密。卫星遥感能够提供大范围、同步与...珊瑚礁白化是由于珊瑚失去体内共生的虫黄藻或者共生的虫黄藻失去体内色素而导致五彩缤纷的珊瑚礁变白的现象,严重的白化可以带来珊瑚礁的死亡。国内外研究表明海水温度升高和珊瑚礁白化关系最为紧密。卫星遥感能够提供大范围、同步与连续的海洋数据,如海水表层温度和海色数据,从而能够及时监测和预测珊瑚礁的白化。基于AVHRR(Advanced Very High Resolution Radiometer),NOAA(National Oceanicand Atmospheric Administration,US)开发了全球监测珊瑚礁白化的方法,热点(HotSpot)和周热度(DHW)两种主要指数。目前,我国珊瑚礁白化现象的监测和研究明显滞后于国际动态,迫切需要发展和利用卫星遥感的方法监测南海珊瑚礁白化状况。展开更多
This paper introduces a novel privacy-aware Federated Proximal Policy Optimization(FPPO)method combined with action masking.As a Federated Reinforcement Learning(FRL)approach,the proposed method is used for optimizing...This paper introduces a novel privacy-aware Federated Proximal Policy Optimization(FPPO)method combined with action masking.As a Federated Reinforcement Learning(FRL)approach,the proposed method is used for optimizing the reloading of Domestic Hot Water(DHW)storage tanks,with a focus on energy savings and DHW thermal comfort in collective heating systems.The proposed approach combines FedProx as the Federated Learning(FL)method and Proximal Policy Optimization(PPO)as the Deep Reinforcement Learning(DRL)technique to address the challenges of distributed control while ensuring data privacy.Key contributions include:(1)employing action masking to guarantee compliance with comfort level,(2)designing a global reward function to align agents actions toward collective energy savings,(3)implementing a privacy-aware design where only model parameters are shared with a global aggregator,avoiding raw data transmission,and(4)optimizing PPO’s loss function for improved performance.PPO was benchmarked using a common FL method(FedAvg)alongside two other DRL methods,where PPO outperformed both in scalability and energy savings,especially in larger systems.Then,PPO-based FRL was refined into FPPO by integrating a proximal term with coefficient into the loss function to enhance the performance.Experiments were conducted with both fixed and dynamically adjusted,with the latter demonstrating better energy savings and comfort.Results show that FPPO achieves up to 10.08%energy savings while maintaining DHW discomfort below 8.72%in systems with at least 20 dwellings.These findings highlight FPPO as a scalable,privacy-aware,and energy-efficient solution for distributed control in collective heating systems.展开更多
For China,the development of low-energy buildings is one of the necessary routes for achieving carbon neutrality.Combining photovoltaic(PV)with air source heat pump(ASHP)yields a great potential in providing heating a...For China,the development of low-energy buildings is one of the necessary routes for achieving carbon neutrality.Combining photovoltaic(PV)with air source heat pump(ASHP)yields a great potential in providing heating and domestic hot water(DHW)supply in non-central heating areas.However,the diurnal and seasonal inconsistencies between solar availability and building heat load can severely affect the efficacy of solar energy systems.This study creates and numerically simulates a PV-ASHP system with thermal energy storage(TES)in transient system simulation software,TRNSYS.Experimental studies are conducted to validate the simulation model.The system’s yearly operational characteristics are simulated to reveal the energy conversion relationship between the system’s thermoelectric storage and heating and DHW demand.The results show that the synergy between heating and DHW simultaneously improves the direct utilization of solar energy compared to single heating.The yearly self-consumption and self-satisfaction rates of PV and the COP of the ASHP increase by 131.25%,10.53%and 9.56%,respectively.Solar energy contributes 55.54%to the system,with a PV capacity of 82 W per square meter of building area.This study provides fresh approaches to developing flexible building-integrated PV-ASHP technologies and balance of the energy exchange among the PV,building load and TES.展开更多
文摘The paper gives a thorough survey of the studies of different authors in the field of domestic hot water (DHW) consumption and consumption profiles. It presents an overview of the research done into DHW by the Tallinn University of Technology. Working out on the basis of investigations has been new empirical formulas for determining design flow rates for schools, kindergartens, office buildings and shopping centres. DHW consumption profiles of typical buildings are presented. Comparisons are given on the determination of DHW design flow rates by the standard EVS 835, the EN 806-3 and the recommended formulas. The latter makes it possible to considerably decrease the design flow rates which in turn enables to deminish the load of the equipment, to improve the quality of control and to decrease the diameters of the pipes of the district heating network and the losses of heat in them.
文摘Worldwide,there are many options to ensure domestic hot water(DHW)provision in dwellings.This study aimed to depict the distribution of energy sources and DHW production systems in the Calabria region.The research was focused on understanding which variables,among contextual variables and building characteristics,may influence the adoption of a particular energy source or production system.Descriptive statistics and chi-square test of independence have been developed.Significant relationships were found between the climatic zone and the energy source used as well as between the climatic zone and the production system installed in both households with a separated and a combined DHW production system.Furthermore,the population of the municipality and the dwelling type resulted to be significant variables for the preference of an energy source or the diffusion of a combined production system.
文摘珊瑚礁白化是由于珊瑚失去体内共生的虫黄藻或者共生的虫黄藻失去体内色素而导致五彩缤纷的珊瑚礁变白的现象,严重的白化可以带来珊瑚礁的死亡。国内外研究表明海水温度升高和珊瑚礁白化关系最为紧密。卫星遥感能够提供大范围、同步与连续的海洋数据,如海水表层温度和海色数据,从而能够及时监测和预测珊瑚礁的白化。基于AVHRR(Advanced Very High Resolution Radiometer),NOAA(National Oceanicand Atmospheric Administration,US)开发了全球监测珊瑚礁白化的方法,热点(HotSpot)和周热度(DHW)两种主要指数。目前,我国珊瑚礁白化现象的监测和研究明显滞后于国际动态,迫切需要发展和利用卫星遥感的方法监测南海珊瑚礁白化状况。
基金funded by a PhD fellowship of the Research Foundation Flanders(FWO)[1S08624N].
文摘This paper introduces a novel privacy-aware Federated Proximal Policy Optimization(FPPO)method combined with action masking.As a Federated Reinforcement Learning(FRL)approach,the proposed method is used for optimizing the reloading of Domestic Hot Water(DHW)storage tanks,with a focus on energy savings and DHW thermal comfort in collective heating systems.The proposed approach combines FedProx as the Federated Learning(FL)method and Proximal Policy Optimization(PPO)as the Deep Reinforcement Learning(DRL)technique to address the challenges of distributed control while ensuring data privacy.Key contributions include:(1)employing action masking to guarantee compliance with comfort level,(2)designing a global reward function to align agents actions toward collective energy savings,(3)implementing a privacy-aware design where only model parameters are shared with a global aggregator,avoiding raw data transmission,and(4)optimizing PPO’s loss function for improved performance.PPO was benchmarked using a common FL method(FedAvg)alongside two other DRL methods,where PPO outperformed both in scalability and energy savings,especially in larger systems.Then,PPO-based FRL was refined into FPPO by integrating a proximal term with coefficient into the loss function to enhance the performance.Experiments were conducted with both fixed and dynamically adjusted,with the latter demonstrating better energy savings and comfort.Results show that FPPO achieves up to 10.08%energy savings while maintaining DHW discomfort below 8.72%in systems with at least 20 dwellings.These findings highlight FPPO as a scalable,privacy-aware,and energy-efficient solution for distributed control in collective heating systems.
基金the National Natural Science Foundation of China(No.51966019)International S&T Cooperation Program of Yunnan,China(No.202003AF140001)Kunming International S&T Cooperation Base of Kunming,China(No.GHJD-2020026).
文摘For China,the development of low-energy buildings is one of the necessary routes for achieving carbon neutrality.Combining photovoltaic(PV)with air source heat pump(ASHP)yields a great potential in providing heating and domestic hot water(DHW)supply in non-central heating areas.However,the diurnal and seasonal inconsistencies between solar availability and building heat load can severely affect the efficacy of solar energy systems.This study creates and numerically simulates a PV-ASHP system with thermal energy storage(TES)in transient system simulation software,TRNSYS.Experimental studies are conducted to validate the simulation model.The system’s yearly operational characteristics are simulated to reveal the energy conversion relationship between the system’s thermoelectric storage and heating and DHW demand.The results show that the synergy between heating and DHW simultaneously improves the direct utilization of solar energy compared to single heating.The yearly self-consumption and self-satisfaction rates of PV and the COP of the ASHP increase by 131.25%,10.53%and 9.56%,respectively.Solar energy contributes 55.54%to the system,with a PV capacity of 82 W per square meter of building area.This study provides fresh approaches to developing flexible building-integrated PV-ASHP technologies and balance of the energy exchange among the PV,building load and TES.
