Currently,people pay more and more attention to the transitional resettlement of victims after various natural disasters.There is an urgent need for a large number of temporary houses to resettle the victims after nat...Currently,people pay more and more attention to the transitional resettlement of victims after various natural disasters.There is an urgent need for a large number of temporary houses to resettle the victims after natural disasters.Disaster-relief temporary houses(DTHs)played an important role in the post-disaster resettlement in the past,which can not only be produced on a large scale,but also can be quickly and conveniently erected,which were the main means to solve the problem of transitional resettlement.However,due to their temporary nature,there was no extra energy consuming system installed in the DTHs generally.Hence the indoor thermal environment inside the DTHs was severe in summer.In this study,combined with the field experimental tests of the DTHs in Wenchuan Earthquake and Lushan Earthquake and the experimental study of the full-size DTH,it found that the thermal environment inside the DTH was intolerably high in summer.It had negative impact on victims.In order to improve the thermal environment inside DTHs during post-disaster period which lacked of extra energy resources,this study used the method of combining phase change materials(PCMs)with walls of the DTH to explore its feasibility and effectiveness.The results showed that PCMs could effectively improve the thermal environment inside the DTH in summer.Furthermore,the difference of the composite positions between PCMs and the wall affected the improvement effect.The energy release rate of the PCMs assembly system(PAS)varied according to the positions of the PCMs.展开更多
Energy is essential for every human activity for more comfortable life, but it also consumes more natural resources. Fossil fuel is the major energy source for energy consumption, and it also emits a lot of air pollut...Energy is essential for every human activity for more comfortable life, but it also consumes more natural resources. Fossil fuel is the major energy source for energy consumption, and it also emits a lot of air pollution during usage to atmosphere and not reproductively. Electrical energy is the secondary energy sources from fossil fuel which is used to operate air conditioning system. In order to control human comfort temperature, it is usually required when the temperature differences swing between indoor and outdoor temperatures. PCMs （phase change materials） are the high latent heat materials which can be used in building materials for energy conservation purpose. PCMs can store thermal energy and prevent heat to pass through temperature control areas. Paraffin has been used as PCMs which is absorbed into the pore of fly ash as paraffin/fly-ash composite and mixed into the buildings materials. Paraffin is an organic material with high melting point （-59 ~C） and nonflammable material, therefore, it can be used as the building materials for the function of PCMs for energy saving purposes. Composite PCMs can be prepared by vacuum impregnation process. Paraffin in liquid form will be impregnated into the pore of fly ash by vacuum capillary force to form paraffin/fly ash composite PCMs. Vacuum impregnation pressures, vacuum times, impregnation times of liquid paraffin in fly ash pores and temperatures for melting the solid paraffin into the liquid form are all affect on the thermal properties of paraffin/fly ash composite PCMs. Composite PCMs will be selected by the optimum thermal properties with optimum of the production conditions for replace the cement powder in the mortar plate compositions. Cement mortar plate with and without composite PCMs will be tested for the thermal insulation properties by comparison as the real day and night time for 8 h period from spot light turn on and off. Temperature detection on the surface and inside the model building under mortar plate with and without composite PCMs is detected every 1 min. Temperature differences between surface of mortar plate over the model building and inside temperature of model building under mortar plates increase with more composite PCMs contents in mortar plates. Thermal insulation efficiency in the building can be enhanced by the composite PCMs utilization as the composition of the building materials.展开更多
An experimental investigation was conducted to study the efficiency of thermal insulation of composite PCMs(phase change materials)produced by vacuum impregnation process between paraffin(PCMs)and fly ash particles.DS...An experimental investigation was conducted to study the efficiency of thermal insulation of composite PCMs(phase change materials)produced by vacuum impregnation process between paraffin(PCMs)and fly ash particles.DSC(differential scanning calorimeter)has been used to determine the thermal properties of latent heat of melting and heat capacity for composite PCMs.Vacuum impregnation pressure of 40 in.Hg,paraffin melting temperature of 90℃,vacuum time and impregnation time of paraffin of 30 min are the optimum condition of composite PCMs productions.The values of latent heat of melting and heat capacity are 74.00 J/g and 15.726 J/g.℃for composite PCMs that produces by the optimum condition in vacuum impregnation process.Increasing the amount of composite PCMs replacing for cement in mortars causes the compressive strength,flexural strength and tensile strength reduction.Compressive strength,flexural strength and tensile strength of mortar with and without composite PCMs can be increased by the longer time of water curing for mortar specimens.Thermal conductivity(k)of mortar cement is reduced by increasing the amount of composite PCMs which replaced for cement in mortar plate compositions.Composite PCMs have the efficiency for thermal energy insulation when incorporated into the buildings.Therefore,this property of paraffin/fly ash composites PCMs can reduce the energy consumption for temperature control in the buildings.展开更多
Energy is essential for every human activity for more comfortable life but also consumes more natural resources. In order to control human comfort, temperature usually required when the differences in temperature swin...Energy is essential for every human activity for more comfortable life but also consumes more natural resources. In order to control human comfort, temperature usually required when the differences in temperature swing between indoor and outdoor temperatures. PCMs （phase change materials） are the high latent heat materials which can be used in building materials for energy conservation purpose. PCMs can store thermal energy and also can prevent heat to pass through temperature control areas. Paraffin has been used as PCMs are absorbed into the pore of fly ash as paraffin/fly-ash composite and mixed into the buildings materials. Paraffin is an organic material with high melting point （-59℃）, and nonflammable materials therefore paraffin can be used as the building materials for the function of PCMs for energy saving purposes. Composite PCMs can be prepared by vacuum impregnation process. Paraffin in liquid form will be impregnated into the pore of fly ash by vacuum capillary force to form paraffin/fly ash composite PCMs. Vacuum impregnation pressures, vacuum times, impregnation times of liquid paraffin in fly ash pores and temperatures for melting the solid paraffin into the liquid form are all affect on the thermal properties of paraffin/fly ash composite PCMs. Paraffin or PCMs impregnation are also relate to the physical property including the fractal dimensions of the pores of the fly ash particles and paraffin/fly ash composite PCMs. The fractal dimensions of the pore of fly ash and paraffin/fiy ash composites PCMs are between the values of 1.0 and 2.0. Fractal dimensions of paraffin/fly-ash composite PCMs have the same trend as the thermal properties for heat capacity and latent heat of melting. These fractal dimensions technique is a novel method to measure physical property of building material related to latent heat and heat capacity.展开更多
Refrigeration systems are essential across various sectors,including food preservation,medical storage,and climate control.However,their high energy consumption and environmental impact necessitate innovative solution...Refrigeration systems are essential across various sectors,including food preservation,medical storage,and climate control.However,their high energy consumption and environmental impact necessitate innovative solutions to enhance efficiency while minimizing energy usage.This paper investigates the integration of Phase Change Materials(PCMs)into a vapor compression refrigeration system to enhance energy efficiency and temperature regulation for food preservation.A multifunctional prototype was tested under two configurations:(1)a standard thermally insulated room,and(2)the same room augmented with eutectic plates filled with either Glaceol(-10℃ melting point)or distilled water(0℃ melting point).Thermocouples were calibrated and deployed to record air and PCM temperatures during freeze–thaw cycles at thermostat setpoints of and Additionally,a-30℃ -35℃ .defrosting resistor and timer were added to mitigate frost buildup,a known cause of efficiency loss.The experimental results show that PCM-enhanced rooms achieved up to 10.98℃ greater temperature stability during defrost cycles and reduced energy consumption by as much as 7.76%(from 0.4584 to 0.4231 kWh/h).Moreover,the effectiveness of PCMs depended strongly on thermostat settings and PCM type,with distilled water demonstrating broader solidification across plates under higher ambient loads.These findings highlight the potential of PCM integration to improve cold-chain performance,offering rapid cooling,moisture retention,and extended product conservation during power interruptions.展开更多
文摘Currently,people pay more and more attention to the transitional resettlement of victims after various natural disasters.There is an urgent need for a large number of temporary houses to resettle the victims after natural disasters.Disaster-relief temporary houses(DTHs)played an important role in the post-disaster resettlement in the past,which can not only be produced on a large scale,but also can be quickly and conveniently erected,which were the main means to solve the problem of transitional resettlement.However,due to their temporary nature,there was no extra energy consuming system installed in the DTHs generally.Hence the indoor thermal environment inside the DTHs was severe in summer.In this study,combined with the field experimental tests of the DTHs in Wenchuan Earthquake and Lushan Earthquake and the experimental study of the full-size DTH,it found that the thermal environment inside the DTH was intolerably high in summer.It had negative impact on victims.In order to improve the thermal environment inside DTHs during post-disaster period which lacked of extra energy resources,this study used the method of combining phase change materials(PCMs)with walls of the DTH to explore its feasibility and effectiveness.The results showed that PCMs could effectively improve the thermal environment inside the DTH in summer.Furthermore,the difference of the composite positions between PCMs and the wall affected the improvement effect.The energy release rate of the PCMs assembly system(PAS)varied according to the positions of the PCMs.
文摘Energy is essential for every human activity for more comfortable life, but it also consumes more natural resources. Fossil fuel is the major energy source for energy consumption, and it also emits a lot of air pollution during usage to atmosphere and not reproductively. Electrical energy is the secondary energy sources from fossil fuel which is used to operate air conditioning system. In order to control human comfort temperature, it is usually required when the temperature differences swing between indoor and outdoor temperatures. PCMs （phase change materials） are the high latent heat materials which can be used in building materials for energy conservation purpose. PCMs can store thermal energy and prevent heat to pass through temperature control areas. Paraffin has been used as PCMs which is absorbed into the pore of fly ash as paraffin/fly-ash composite and mixed into the buildings materials. Paraffin is an organic material with high melting point （-59 ~C） and nonflammable material, therefore, it can be used as the building materials for the function of PCMs for energy saving purposes. Composite PCMs can be prepared by vacuum impregnation process. Paraffin in liquid form will be impregnated into the pore of fly ash by vacuum capillary force to form paraffin/fly ash composite PCMs. Vacuum impregnation pressures, vacuum times, impregnation times of liquid paraffin in fly ash pores and temperatures for melting the solid paraffin into the liquid form are all affect on the thermal properties of paraffin/fly ash composite PCMs. Composite PCMs will be selected by the optimum thermal properties with optimum of the production conditions for replace the cement powder in the mortar plate compositions. Cement mortar plate with and without composite PCMs will be tested for the thermal insulation properties by comparison as the real day and night time for 8 h period from spot light turn on and off. Temperature detection on the surface and inside the model building under mortar plate with and without composite PCMs is detected every 1 min. Temperature differences between surface of mortar plate over the model building and inside temperature of model building under mortar plates increase with more composite PCMs contents in mortar plates. Thermal insulation efficiency in the building can be enhanced by the composite PCMs utilization as the composition of the building materials.
文摘An experimental investigation was conducted to study the efficiency of thermal insulation of composite PCMs(phase change materials)produced by vacuum impregnation process between paraffin(PCMs)and fly ash particles.DSC(differential scanning calorimeter)has been used to determine the thermal properties of latent heat of melting and heat capacity for composite PCMs.Vacuum impregnation pressure of 40 in.Hg,paraffin melting temperature of 90℃,vacuum time and impregnation time of paraffin of 30 min are the optimum condition of composite PCMs productions.The values of latent heat of melting and heat capacity are 74.00 J/g and 15.726 J/g.℃for composite PCMs that produces by the optimum condition in vacuum impregnation process.Increasing the amount of composite PCMs replacing for cement in mortars causes the compressive strength,flexural strength and tensile strength reduction.Compressive strength,flexural strength and tensile strength of mortar with and without composite PCMs can be increased by the longer time of water curing for mortar specimens.Thermal conductivity(k)of mortar cement is reduced by increasing the amount of composite PCMs which replaced for cement in mortar plate compositions.Composite PCMs have the efficiency for thermal energy insulation when incorporated into the buildings.Therefore,this property of paraffin/fly ash composites PCMs can reduce the energy consumption for temperature control in the buildings.
文摘Energy is essential for every human activity for more comfortable life but also consumes more natural resources. In order to control human comfort, temperature usually required when the differences in temperature swing between indoor and outdoor temperatures. PCMs （phase change materials） are the high latent heat materials which can be used in building materials for energy conservation purpose. PCMs can store thermal energy and also can prevent heat to pass through temperature control areas. Paraffin has been used as PCMs are absorbed into the pore of fly ash as paraffin/fly-ash composite and mixed into the buildings materials. Paraffin is an organic material with high melting point （-59℃）, and nonflammable materials therefore paraffin can be used as the building materials for the function of PCMs for energy saving purposes. Composite PCMs can be prepared by vacuum impregnation process. Paraffin in liquid form will be impregnated into the pore of fly ash by vacuum capillary force to form paraffin/fly ash composite PCMs. Vacuum impregnation pressures, vacuum times, impregnation times of liquid paraffin in fly ash pores and temperatures for melting the solid paraffin into the liquid form are all affect on the thermal properties of paraffin/fly ash composite PCMs. Paraffin or PCMs impregnation are also relate to the physical property including the fractal dimensions of the pores of the fly ash particles and paraffin/fly ash composite PCMs. The fractal dimensions of the pore of fly ash and paraffin/fiy ash composites PCMs are between the values of 1.0 and 2.0. Fractal dimensions of paraffin/fly-ash composite PCMs have the same trend as the thermal properties for heat capacity and latent heat of melting. These fractal dimensions technique is a novel method to measure physical property of building material related to latent heat and heat capacity.
基金supported in entire part by the Biomaterials and Transport Phenomena Laboratory Agreement No.30303-12-2003,at the University of Medea.
文摘Refrigeration systems are essential across various sectors,including food preservation,medical storage,and climate control.However,their high energy consumption and environmental impact necessitate innovative solutions to enhance efficiency while minimizing energy usage.This paper investigates the integration of Phase Change Materials(PCMs)into a vapor compression refrigeration system to enhance energy efficiency and temperature regulation for food preservation.A multifunctional prototype was tested under two configurations:(1)a standard thermally insulated room,and(2)the same room augmented with eutectic plates filled with either Glaceol(-10℃ melting point)or distilled water(0℃ melting point).Thermocouples were calibrated and deployed to record air and PCM temperatures during freeze–thaw cycles at thermostat setpoints of and Additionally,a-30℃ -35℃ .defrosting resistor and timer were added to mitigate frost buildup,a known cause of efficiency loss.The experimental results show that PCM-enhanced rooms achieved up to 10.98℃ greater temperature stability during defrost cycles and reduced energy consumption by as much as 7.76%(from 0.4584 to 0.4231 kWh/h).Moreover,the effectiveness of PCMs depended strongly on thermostat settings and PCM type,with distilled water demonstrating broader solidification across plates under higher ambient loads.These findings highlight the potential of PCM integration to improve cold-chain performance,offering rapid cooling,moisture retention,and extended product conservation during power interruptions.
