By testing indoor and outdoor thermal environment of residential buildings that apply 4 mostused heating ways in Hantai District,Hanzhong City,this paper explored the indoor thermal environment conditions of different...By testing indoor and outdoor thermal environment of residential buildings that apply 4 mostused heating ways in Hantai District,Hanzhong City,this paper explored the indoor thermal environment conditions of different heating ways,to provide references for choosing a suitable heating way in the local area.展开更多
A design of a solar-wind electrical hybrid system to supply space heating requirements for a 1,200 m^2 residential building in Amman-Jordan was implemented. The building heating requirements were estimated from existi...A design of a solar-wind electrical hybrid system to supply space heating requirements for a 1,200 m^2 residential building in Amman-Jordan was implemented. The building heating requirements were estimated from existing heating building data based on traditional heating design already adopted by engineering firms in Jordan. The traditional heating load was transferred into electrical load to be supplied by hybrid system. The hybrid system consists of a 75 kW vertical axis windmill and 140 solar modules. Because of the high cost of land in residential buildings, the hybrid system is to be installed on the building roof. The hybrid system and the conventional systems＇ cost were found to be compatible in four years period when oil prices reach $100 per barrel. As the international price of oil rises above $100 per barrel, the proposed hybrid system becomes more economical than the already existing hot water heating system.展开更多
To investigate the impact of building heat transfer on roof snow loads,roof snow loads and snow load thermal coefficients from 61 Chinese sites over a period of 50 years are simulated based on basic meteorological dat...To investigate the impact of building heat transfer on roof snow loads,roof snow loads and snow load thermal coefficients from 61 Chinese sites over a period of 50 years are simulated based on basic meteorological data such as temperature,humidity,wind speed,and precipitation,and a multi-layer snowmelt model considering the building heat transfer.Firstly,the accuracy of the multi-layer snowmelt model is validated using the data of observed ground snow load and roof snow melting tests.The relationship between meteorological conditions,snow cover characteristics,and thermal coefficients of snow loads in three representative sites is then studied.Furthermore,the characteristics of thermal coefficients in each zone are analyzed by combining them with the statistical results of meteorological data from 1960 to 2010,and the equations of thermal coefficients in different zones on indoor temperatures and roof heat transfer coefficients are fitted separately.Finally,the equations in this paper are compared with the thermal coefficients in the main snow load codes.The results indicate that the snowmelt model using basic meteorological data can effectively provide samples of roof snow loads.In the cold zone where the snow cover lasts for a long time and does not melt easily,the thermal coefficients of the snow loads on the heating buildings are lower than those in the warm zone due to the long-term influence of the heat from inside the buildings.Thermal coefficients are negatively correlated with indoor temperatures and roof heat transfer coefficients.When the indoor temperature is too low or the roof insulation is good,the roof snow load may exceed the ground snow load.The thermal coefficients for heated buildings in the main snow load codes are more conservative than those calculated in this paper,and the thermal coefficients for buildings with lower indoor temperatures tend to be smaller.展开更多
Building is an important scenario for achieving global carbon peak and carbon neutrality goals,accounting for approximately 37%of global energy-related CO_(2) emissions in 2020.In the meanwhile,the construction and op...Building is an important scenario for achieving global carbon peak and carbon neutrality goals,accounting for approximately 37%of global energy-related CO_(2) emissions in 2020.In the meanwhile,the construction and operation of buildings was responsible for 36%of global energy consumption,of which 30%energy was used for space heating.Therefore,this paper proposes a low-carbon building heating system that is coupled to a new semiconductor radiation heating unit and distributed rooftop photovoltaic to reduce carbon emissions.To reveal its building heating characteristics,a dynamic model of heat transfer based on semiconductor low-temperature radiant heating is first established by analyzing the heat conduction,convection,and radiation models,and the uncertainty from both the distributed rooftop photovoltaic and building heating demand is considered in the building heating operation strategy.Then,a simulation model of a low-carbon building heating system is built in MATLAB/SIMULINK for two different climate zones in China(Beijing and Wuhan).When building and using the low-carbon building heating system stable for 30 years,the payback period is 5.2–8.2 years in Beijing and 6.4–11.6 years in Wuhan.Compared with the traditional grid-powered heating system,the simulation revealed that the carbon emissions of Beijing and Wuhan during the heating season are reduced by 44.9%and 44.3%,respectively,and the corresponding building heating cost is saved by 62.1%and 57.8%.展开更多
The distributed energy system has achieved significant attention in respect of its application for singlebuilding cooling and heating.Researching on the life cycle environmental impact of distributed energy systems(DE...The distributed energy system has achieved significant attention in respect of its application for singlebuilding cooling and heating.Researching on the life cycle environmental impact of distributed energy systems(DES)is of great significance to encourage and guide the development of DES in China.However,the environmental performance of distributed energy systems in a building cooling and heating has not yet been carefully analyzed.In this study,based on the standards of ISO14040-2006 and ISO14044-2006,a life-cycle assessment(LCA)of a DES was conducted to quantify its environmental impact and a conventional energy system(CES)was used as the benchmark.GaBi 8 software was used for the LCA.And the Centre of Environmental Science(CML)method and Eco-indicator 99(EI 99)method were used for environmental impact assessment of midpoint and endpoint levels respectively.The results indicated that the DES showed a better life-cycle performance in the usage phase compared to the CES.The life-cycle performance of the DES was better than that of the CES both at the midpoint and endpoint levels in view of the whole lifespan.It is because the CES to DES indicator ratios for acidification potential,eutrophication potential,and global warming potential are 1.5,1.5,and 1.6,respectively at the midpoint level.And about the two types of impact indicators of ecosystem quality and human health at the endpoint level,the CES and DES ratios of the other indicators are greater than1 excepting the carcinogenicity and ozone depletion indicators.The human health threat for the DES was mainly caused by energy consumption during the usage phase.A sensitivity analysis showed that the climate change and inhalable inorganic matter varied by 1.3%and 6.1%as the electricity increased by 10%.When the natural gas increased by 10%,the climate change and inhalable inorganic matter increased by 6.3%and 3.4%,respectively.The human health threat and environmental damage caused by the DES could be significantly reduced by the optimization of natural gas and electricity consumption.展开更多
The removal building heat load and electrical power consumption by air conditioning system are proportional to the outside conditions and solar radiation intensity. Building construction materials has substantial effe...The removal building heat load and electrical power consumption by air conditioning system are proportional to the outside conditions and solar radiation intensity. Building construction materials has substantial effects on the transmission heat through outer walls, ceiling and glazing windows. Good thermal isolation for buildings is important to reduce the transmitted heat and consumed power. The buildings models are constructed from common materials with 0 - 16 cm of thermal insulation thickness in the outer walls and ceilings, and double-layers glazing windows. The building heat loads were calculated for two types of walls and ceiling with and without thermal insulation. The cooling load temperature difference method, <em>CLTD</em>, was used to estimate the building heat load during a 24-hour each day throughout spring, summer, autumn and winter seasons. The annual cooling degree-day, <em>CDD</em> was used to estimate the optimal thermal insulation thickness and payback period with including the solar radiation effect on the outer walls surfaces. The average saved energy percentage in summer, spring, autumn and winter are 35.5%, 32.8%, 33.2% and 30.7% respectively, and average yearly saved energy is about of 33.5%. The optimal thermal insulation thickness was obtained between 7 - 12 cm and payback period of 20 - 30 month for some Egyptian Cities according to the Latitude and annual degree-days.展开更多
Boom clay formation is a potential natural host rock for geological disposal of high-level nuclear waste in Belgium.Heating pulse tests with controlled power supply（maximum temperature was limited to 85℃） and contr...Boom clay formation is a potential natural host rock for geological disposal of high-level nuclear waste in Belgium.Heating pulse tests with controlled power supply（maximum temperature was limited to 85℃） and controlled hydraulic boundary conditions were performed under nearly constant volume conditions to study the impact of thermal loading on the clay formation.Selected test results of intact borehole samples retrieved in horizontal direction are presented and discussed.The study focuses on the time evolution of temperature and pore water pressure changes along heating and cooling paths,i.e.pore pressure build-up during quasi-undrained heating and later dissipation at constant temperature.展开更多
文摘By testing indoor and outdoor thermal environment of residential buildings that apply 4 mostused heating ways in Hantai District,Hanzhong City,this paper explored the indoor thermal environment conditions of different heating ways,to provide references for choosing a suitable heating way in the local area.
文摘A design of a solar-wind electrical hybrid system to supply space heating requirements for a 1,200 m^2 residential building in Amman-Jordan was implemented. The building heating requirements were estimated from existing heating building data based on traditional heating design already adopted by engineering firms in Jordan. The traditional heating load was transferred into electrical load to be supplied by hybrid system. The hybrid system consists of a 75 kW vertical axis windmill and 140 solar modules. Because of the high cost of land in residential buildings, the hybrid system is to be installed on the building roof. The hybrid system and the conventional systems＇ cost were found to be compatible in four years period when oil prices reach $100 per barrel. As the international price of oil rises above $100 per barrel, the proposed hybrid system becomes more economical than the already existing hot water heating system.
基金the National Natural Science Foundation of China(52078380)。
文摘To investigate the impact of building heat transfer on roof snow loads,roof snow loads and snow load thermal coefficients from 61 Chinese sites over a period of 50 years are simulated based on basic meteorological data such as temperature,humidity,wind speed,and precipitation,and a multi-layer snowmelt model considering the building heat transfer.Firstly,the accuracy of the multi-layer snowmelt model is validated using the data of observed ground snow load and roof snow melting tests.The relationship between meteorological conditions,snow cover characteristics,and thermal coefficients of snow loads in three representative sites is then studied.Furthermore,the characteristics of thermal coefficients in each zone are analyzed by combining them with the statistical results of meteorological data from 1960 to 2010,and the equations of thermal coefficients in different zones on indoor temperatures and roof heat transfer coefficients are fitted separately.Finally,the equations in this paper are compared with the thermal coefficients in the main snow load codes.The results indicate that the snowmelt model using basic meteorological data can effectively provide samples of roof snow loads.In the cold zone where the snow cover lasts for a long time and does not melt easily,the thermal coefficients of the snow loads on the heating buildings are lower than those in the warm zone due to the long-term influence of the heat from inside the buildings.Thermal coefficients are negatively correlated with indoor temperatures and roof heat transfer coefficients.When the indoor temperature is too low or the roof insulation is good,the roof snow load may exceed the ground snow load.The thermal coefficients for heated buildings in the main snow load codes are more conservative than those calculated in this paper,and the thermal coefficients for buildings with lower indoor temperatures tend to be smaller.
基金supported by the National Natural Science Foundation of China(No.52006114).
文摘Building is an important scenario for achieving global carbon peak and carbon neutrality goals,accounting for approximately 37%of global energy-related CO_(2) emissions in 2020.In the meanwhile,the construction and operation of buildings was responsible for 36%of global energy consumption,of which 30%energy was used for space heating.Therefore,this paper proposes a low-carbon building heating system that is coupled to a new semiconductor radiation heating unit and distributed rooftop photovoltaic to reduce carbon emissions.To reveal its building heating characteristics,a dynamic model of heat transfer based on semiconductor low-temperature radiant heating is first established by analyzing the heat conduction,convection,and radiation models,and the uncertainty from both the distributed rooftop photovoltaic and building heating demand is considered in the building heating operation strategy.Then,a simulation model of a low-carbon building heating system is built in MATLAB/SIMULINK for two different climate zones in China(Beijing and Wuhan).When building and using the low-carbon building heating system stable for 30 years,the payback period is 5.2–8.2 years in Beijing and 6.4–11.6 years in Wuhan.Compared with the traditional grid-powered heating system,the simulation revealed that the carbon emissions of Beijing and Wuhan during the heating season are reduced by 44.9%and 44.3%,respectively,and the corresponding building heating cost is saved by 62.1%and 57.8%.
基金Projects(51676209,22008265)supported by the National Natural Science Foundation of ChinaProjects(2020JJ6072,2021JJ50007)supported by the Hunan Province Natural Science Foundation,China。
文摘The distributed energy system has achieved significant attention in respect of its application for singlebuilding cooling and heating.Researching on the life cycle environmental impact of distributed energy systems(DES)is of great significance to encourage and guide the development of DES in China.However,the environmental performance of distributed energy systems in a building cooling and heating has not yet been carefully analyzed.In this study,based on the standards of ISO14040-2006 and ISO14044-2006,a life-cycle assessment(LCA)of a DES was conducted to quantify its environmental impact and a conventional energy system(CES)was used as the benchmark.GaBi 8 software was used for the LCA.And the Centre of Environmental Science(CML)method and Eco-indicator 99(EI 99)method were used for environmental impact assessment of midpoint and endpoint levels respectively.The results indicated that the DES showed a better life-cycle performance in the usage phase compared to the CES.The life-cycle performance of the DES was better than that of the CES both at the midpoint and endpoint levels in view of the whole lifespan.It is because the CES to DES indicator ratios for acidification potential,eutrophication potential,and global warming potential are 1.5,1.5,and 1.6,respectively at the midpoint level.And about the two types of impact indicators of ecosystem quality and human health at the endpoint level,the CES and DES ratios of the other indicators are greater than1 excepting the carcinogenicity and ozone depletion indicators.The human health threat for the DES was mainly caused by energy consumption during the usage phase.A sensitivity analysis showed that the climate change and inhalable inorganic matter varied by 1.3%and 6.1%as the electricity increased by 10%.When the natural gas increased by 10%,the climate change and inhalable inorganic matter increased by 6.3%and 3.4%,respectively.The human health threat and environmental damage caused by the DES could be significantly reduced by the optimization of natural gas and electricity consumption.
文摘The removal building heat load and electrical power consumption by air conditioning system are proportional to the outside conditions and solar radiation intensity. Building construction materials has substantial effects on the transmission heat through outer walls, ceiling and glazing windows. Good thermal isolation for buildings is important to reduce the transmitted heat and consumed power. The buildings models are constructed from common materials with 0 - 16 cm of thermal insulation thickness in the outer walls and ceilings, and double-layers glazing windows. The building heat loads were calculated for two types of walls and ceiling with and without thermal insulation. The cooling load temperature difference method, <em>CLTD</em>, was used to estimate the building heat load during a 24-hour each day throughout spring, summer, autumn and winter seasons. The annual cooling degree-day, <em>CDD</em> was used to estimate the optimal thermal insulation thickness and payback period with including the solar radiation effect on the outer walls surfaces. The average saved energy percentage in summer, spring, autumn and winter are 35.5%, 32.8%, 33.2% and 30.7% respectively, and average yearly saved energy is about of 33.5%. The optimal thermal insulation thickness was obtained between 7 - 12 cm and payback period of 20 - 30 month for some Egyptian Cities according to the Latitude and annual degree-days.
基金support provided by EIG EURIDICE/SCK.CEN(Belgium)through a PhD collaboration project with International Centre for Numerical Methods in Engineering(CIMNE,Spain)
文摘Boom clay formation is a potential natural host rock for geological disposal of high-level nuclear waste in Belgium.Heating pulse tests with controlled power supply（maximum temperature was limited to 85℃） and controlled hydraulic boundary conditions were performed under nearly constant volume conditions to study the impact of thermal loading on the clay formation.Selected test results of intact borehole samples retrieved in horizontal direction are presented and discussed.The study focuses on the time evolution of temperature and pore water pressure changes along heating and cooling paths,i.e.pore pressure build-up during quasi-undrained heating and later dissipation at constant temperature.
