The thermal-environment characteristics of the existing forced-convection cooling system were compared with those of the convective cooling system, which combined the radiant-floor cooling system using floor-heating p...The thermal-environment characteristics of the existing forced-convection cooling system were compared with those of the convective cooling system, which combined the radiant-floor cooling system using floor-heating panel typically applied to apartments in South Korea with the forced-convection cooling system using improved fan coil unit. The subjective warm/cool-feeling responses to the combined radiant-floor and convective cooling system in the questionnaire survey conducted among the test subjects were analyzed to establish the basic data for the combined cooling system. The results show that in the thermal-equilibrium condition, the vertical air temperature difference in the model living room is larger in the forced-convection-cooling condition. Most of the subjects feel a proper warm/cool feeling on their entire body, but they feel colder on the foot and lower body in the combined-cooling condition.展开更多
Forced convective heat transfer in micro-rectangular channels can be described by a group of twodimensional differential equations. These equations take the conduction in microchannel wb along the direction of flow of...Forced convective heat transfer in micro-rectangular channels can be described by a group of twodimensional differential equations. These equations take the conduction in microchannel wb along the direction of flow of coolants into account, which are more generalized than those which neglect the conduction. For the same reason, they are suitable particularly for gases-cooled microchannels.With only numerical solution to the equations till today, an approximate analytic solution is derived here. From this solution, a rather simple formula can be introduced bober, by which the differences between considering the conduction and neglecting it are easily found. In addition, the rcasonableness of the classical fin method is also discussed. An experimental example of air-cooled microchannels is illustrated.展开更多
基金Project(NRF-2013RIA2A1A01014020)supported by the National Research Foundation of Korea
文摘The thermal-environment characteristics of the existing forced-convection cooling system were compared with those of the convective cooling system, which combined the radiant-floor cooling system using floor-heating panel typically applied to apartments in South Korea with the forced-convection cooling system using improved fan coil unit. The subjective warm/cool-feeling responses to the combined radiant-floor and convective cooling system in the questionnaire survey conducted among the test subjects were analyzed to establish the basic data for the combined cooling system. The results show that in the thermal-equilibrium condition, the vertical air temperature difference in the model living room is larger in the forced-convection-cooling condition. Most of the subjects feel a proper warm/cool feeling on their entire body, but they feel colder on the foot and lower body in the combined-cooling condition.
文摘Forced convective heat transfer in micro-rectangular channels can be described by a group of twodimensional differential equations. These equations take the conduction in microchannel wb along the direction of flow of coolants into account, which are more generalized than those which neglect the conduction. For the same reason, they are suitable particularly for gases-cooled microchannels.With only numerical solution to the equations till today, an approximate analytic solution is derived here. From this solution, a rather simple formula can be introduced bober, by which the differences between considering the conduction and neglecting it are easily found. In addition, the rcasonableness of the classical fin method is also discussed. An experimental example of air-cooled microchannels is illustrated.
