Paper deals about testing of device with gravity assisted heat pipes and about researching of wick heat pipes used to effective heat transfers from power switches of energy converter. At first, to simulate ambient con...Paper deals about testing of device with gravity assisted heat pipes and about researching of wick heat pipes used to effective heat transfers from power switches of energy converter. At first, to simulate ambient condition was designed thermostatic chamber where was monitoring temperature course on main parts of cooling device （energy converter, air cooler and heat pipes） at various position of cooling device. It was found, if the cooling device is in tilt position the cooling performance is better. But if the tilt angel of gravity assisted heat pipe is higher the heat transfer is lower. From reason improve heat transfer cooling device at tilt angle are manufactured heat pipes with the sintered, mesh screen and grooved capillary structures and tested their thermal performance at vertical and tilt angel 45~ position by calorimetric method. Article describes manufacturing process and thermal performance measuring method of wick heat pipes. This experiment testify that the wick heat pipe is able operate at tilt angle position than gravity assisted heat pipe and application of wick heat pipes into cooling device will improve his cooling performance.展开更多
The aim of the present analysis concerns the magnetohydrodynamic flow of fluid which is natural convective and electrically charged through two vertical insulated walls.Influences of radiative heat flux,induced magnet...The aim of the present analysis concerns the magnetohydrodynamic flow of fluid which is natural convective and electrically charged through two vertical insulated walls.Influences of radiative heat flux,induced magnetic field,and the Newtonian heating/cooling are taken.We found exact expressions for the temperature field,the velocity field,and the induced magnetic field by solving the set of dimensionless coupled governing equations.Further,we obtained the equations for induced current density,Nusselt number,skin frictions as well as mass flux.The influences of the several constraints like the magnetic,the radiation and the Newtonian heating/cooling on the profiles of the velocity,the temperature field,the induced magnetic field as well as the current density display with graphics.Moreover,the influence of these non-dimensional parameters on the skin frictions,the Nusselt number,and the mass flux is explored in tabular form.The outcome of the radiation raised the velocity,the temperature field,the induced magnetic field and the current density field in view of enhancing the thickness of the boundary layer.Also,the impact of Newtonian heating is to raise the velocity,temperature,induced magnetic field and induced current density,whereas all these fields have opposite behaviors in case of Newtonian cooling.展开更多
In recent years, the number of public office buildings which were built by the glass curtain wall increased rapidly, but through the results of the investigation of the government, these buildings have been found that...In recent years, the number of public office buildings which were built by the glass curtain wall increased rapidly, but through the results of the investigation of the government, these buildings have been found that the heating and cooling load is high, and showed low energy efficiency. So in this study, through energy simulation, the energy consumption of public office building was verified and measured;environment data and calculated data were compared to make more precise simulation. The heating and cooling load was calculated via EnergyPlus;building was modeled by Google SketchUp connected to EnergyPlus. The results of this study were as follows: in simulation, incident solar radiation from large curtain wall should be underestimated. And using site-measured outdoor environment data can increase accuracy of simulation result.展开更多
The purpose of this paper is to present the design and performance of a skylight using a mathematical model. This model uses weather data from the Finnish city Helsinki to assess its performance. This skylight could a...The purpose of this paper is to present the design and performance of a skylight using a mathematical model. This model uses weather data from the Finnish city Helsinki to assess its performance. This skylight could act as a radiative cooler or as a thermal insulator depending on the need. This versatile usage would thus decrease the need for traditional air-conditioning and hence save electricity. The skylight would consist of one normal silica glass window and of two polymer windows with a grcenhousc gas trapped in the spaces between the windows. The skylight would be in its cooling mode when the two spaces would be connected to each other and insulating when disconnected. Thus when cooling, a natural convective flow transports heat from the 1o~ er part of the skylight to the upper part of the skylight where the greenhouse gas is cooled by radiative heat exchange with the sky.展开更多
The article is dedicated to the issues of heat transfer, radiant heat transfer in particular, between fluidized bed of coke and water-cooled panels arranged inside it in a staggered order. The model by A.F. Chudnovsky...The article is dedicated to the issues of heat transfer, radiant heat transfer in particular, between fluidized bed of coke and water-cooled panels arranged inside it in a staggered order. The model by A.F. Chudnovsky describing radiant heat transfer in a porous body (disperse medium) as applied to coke bed has been updated.展开更多
When a historic façade needs to be preserved or when the seismic considerations favor use of a concrete wall system and fire considerations limit exterior thermal insulation,one needs to use interior thermal insu...When a historic façade needs to be preserved or when the seismic considerations favor use of a concrete wall system and fire considerations limit exterior thermal insulation,one needs to use interior thermal insulation systems.Interior thermal insulation systems are less effective than the exterior systems and will not reduce the effect of thermal bridges.Yet they may be successfully used and,in many instances,are recommended as a complement to the exterior insulation.This paper presents one of these cases.It is focused on the most successful applications of capillary active,dynamic interior thermal insulation.This happens when such insulation is integrated with heating,cooling and ventilation,air conditioning(HVAC)system.Starting with a pioneering work of the Technical University in Dresden in development of capillary active interior insulations,we propose a next generation,namely,a bio-fiber thermal insulation.When completing the review,this paper proposes a concept of a joint research project to be undertaken by partners from the US(where improvement of indoor climate in exposed coastal areas is needed),China(indoor climate in non-air conditioned concrete buildings is an issue),and Germany(where the bio-fiber technology has been developed).展开更多
An investigation of the decoupled thermal–hydraulic analysis of a separated heat pipe spent fuel pool passive cooling system(SFS)is essential for practical engineering applications.Based on the principles of thermal ...An investigation of the decoupled thermal–hydraulic analysis of a separated heat pipe spent fuel pool passive cooling system(SFS)is essential for practical engineering applications.Based on the principles of thermal and mass balance,this study decoupled the heat transfer processes in the SFS.In accordance with the decoupling conditions,we modeled the spent fuel pool of the CAP1400 pressurized water reactor in Weihai and used computational fluid dynamics to explore the heat dissipation capacity of the SFS under different air temperatures and wind speeds.The results show that the air-cooled separated heat pipe radiator achieved optimal performance at an air temperature of 10℃ or wind speed of 8 m/s.Fitted equations for the equivalent thermal conductivity of the separated heat pipes with the wind speed and air temperature we obtained according to the thermal resistance network model.This study is instructive for the actual operation of an SFS.展开更多
文摘Paper deals about testing of device with gravity assisted heat pipes and about researching of wick heat pipes used to effective heat transfers from power switches of energy converter. At first, to simulate ambient condition was designed thermostatic chamber where was monitoring temperature course on main parts of cooling device （energy converter, air cooler and heat pipes） at various position of cooling device. It was found, if the cooling device is in tilt position the cooling performance is better. But if the tilt angel of gravity assisted heat pipe is higher the heat transfer is lower. From reason improve heat transfer cooling device at tilt angle are manufactured heat pipes with the sintered, mesh screen and grooved capillary structures and tested their thermal performance at vertical and tilt angel 45~ position by calorimetric method. Article describes manufacturing process and thermal performance measuring method of wick heat pipes. This experiment testify that the wick heat pipe is able operate at tilt angle position than gravity assisted heat pipe and application of wick heat pipes into cooling device will improve his cooling performance.
文摘The aim of the present analysis concerns the magnetohydrodynamic flow of fluid which is natural convective and electrically charged through two vertical insulated walls.Influences of radiative heat flux,induced magnetic field,and the Newtonian heating/cooling are taken.We found exact expressions for the temperature field,the velocity field,and the induced magnetic field by solving the set of dimensionless coupled governing equations.Further,we obtained the equations for induced current density,Nusselt number,skin frictions as well as mass flux.The influences of the several constraints like the magnetic,the radiation and the Newtonian heating/cooling on the profiles of the velocity,the temperature field,the induced magnetic field as well as the current density display with graphics.Moreover,the influence of these non-dimensional parameters on the skin frictions,the Nusselt number,and the mass flux is explored in tabular form.The outcome of the radiation raised the velocity,the temperature field,the induced magnetic field and the current density field in view of enhancing the thickness of the boundary layer.Also,the impact of Newtonian heating is to raise the velocity,temperature,induced magnetic field and induced current density,whereas all these fields have opposite behaviors in case of Newtonian cooling.
文摘In recent years, the number of public office buildings which were built by the glass curtain wall increased rapidly, but through the results of the investigation of the government, these buildings have been found that the heating and cooling load is high, and showed low energy efficiency. So in this study, through energy simulation, the energy consumption of public office building was verified and measured;environment data and calculated data were compared to make more precise simulation. The heating and cooling load was calculated via EnergyPlus;building was modeled by Google SketchUp connected to EnergyPlus. The results of this study were as follows: in simulation, incident solar radiation from large curtain wall should be underestimated. And using site-measured outdoor environment data can increase accuracy of simulation result.
文摘The purpose of this paper is to present the design and performance of a skylight using a mathematical model. This model uses weather data from the Finnish city Helsinki to assess its performance. This skylight could act as a radiative cooler or as a thermal insulator depending on the need. This versatile usage would thus decrease the need for traditional air-conditioning and hence save electricity. The skylight would consist of one normal silica glass window and of two polymer windows with a grcenhousc gas trapped in the spaces between the windows. The skylight would be in its cooling mode when the two spaces would be connected to each other and insulating when disconnected. Thus when cooling, a natural convective flow transports heat from the 1o~ er part of the skylight to the upper part of the skylight where the greenhouse gas is cooled by radiative heat exchange with the sky.
文摘The article is dedicated to the issues of heat transfer, radiant heat transfer in particular, between fluidized bed of coke and water-cooled panels arranged inside it in a staggered order. The model by A.F. Chudnovsky describing radiant heat transfer in a porous body (disperse medium) as applied to coke bed has been updated.
文摘When a historic façade needs to be preserved or when the seismic considerations favor use of a concrete wall system and fire considerations limit exterior thermal insulation,one needs to use interior thermal insulation systems.Interior thermal insulation systems are less effective than the exterior systems and will not reduce the effect of thermal bridges.Yet they may be successfully used and,in many instances,are recommended as a complement to the exterior insulation.This paper presents one of these cases.It is focused on the most successful applications of capillary active,dynamic interior thermal insulation.This happens when such insulation is integrated with heating,cooling and ventilation,air conditioning(HVAC)system.Starting with a pioneering work of the Technical University in Dresden in development of capillary active interior insulations,we propose a next generation,namely,a bio-fiber thermal insulation.When completing the review,this paper proposes a concept of a joint research project to be undertaken by partners from the US(where improvement of indoor climate in exposed coastal areas is needed),China(indoor climate in non-air conditioned concrete buildings is an issue),and Germany(where the bio-fiber technology has been developed).
文摘An investigation of the decoupled thermal–hydraulic analysis of a separated heat pipe spent fuel pool passive cooling system(SFS)is essential for practical engineering applications.Based on the principles of thermal and mass balance,this study decoupled the heat transfer processes in the SFS.In accordance with the decoupling conditions,we modeled the spent fuel pool of the CAP1400 pressurized water reactor in Weihai and used computational fluid dynamics to explore the heat dissipation capacity of the SFS under different air temperatures and wind speeds.The results show that the air-cooled separated heat pipe radiator achieved optimal performance at an air temperature of 10℃ or wind speed of 8 m/s.Fitted equations for the equivalent thermal conductivity of the separated heat pipes with the wind speed and air temperature we obtained according to the thermal resistance network model.This study is instructive for the actual operation of an SFS.
