Heat-ray absorbing sheet glass can decrease electric energy used for air-conditioning by controling the incoming heat-ray through windows into the rooms.On the other hand,the glasses increase the temperature and somet...Heat-ray absorbing sheet glass can decrease electric energy used for air-conditioning by controling the incoming heat-ray through windows into the rooms.On the other hand,the glasses increase the temperature and sometimes yield heat cracks by thermal stresses.It is important to know the state of thermal stress accurately in order to develop heat-ray absorbing sheet glasses with higher performance and without heat cracks.A conventional design manual at field site treats the steady state and the thermal boundary condition that all heat-rays are absorbed at glass surface.In this paper,it is assumed that the heat-ray is absorbed over all the plate thickness.The idea of the local absorptibity per unit length is introduced.The modeling of internal heat absorbing process is proposed.It can explain well that the total absorptivity depends on the plate thickness.The temperature and the thermal stresses are calculated and discussed.Sudden weather changes such as rain and/or wind after the glass is heated to be steady state are also discussed.Those weather changes are treated with the change of amount of absorbed heat-ray and/or the change of heat transfer coefficient between the glass surface and the outside atmosphere.展开更多
Heat-ray absorbing film is used to be bonded on the existing sheet glasses of the windows.It is effective for air-conditioning energy saving against the global warming,because it absorbs heat-ray in the thin film and ...Heat-ray absorbing film is used to be bonded on the existing sheet glasses of the windows.It is effective for air-conditioning energy saving against the global warming,because it absorbs heat-ray in the thin film and decreases the incoming heat-ray into the room.On the other hand,the sheet glasses increase the temperature at the surface which the sheet is bonded and sometimes yield heat cracks by thermal stresses.It is important to know the state of thermal stresses accurately in order to develop the heat-ray absorbing film with higher performance and without heat cracks.In this paper,the analysis model is treated as the two-layer plate of the conventional soda sheet glass and the heat-ray absorbing film with different absorptivities.The unsteady temperature and thermal stresses are analyzed and calculated numerically.The influence of the patch side,which the heat-ray absorbing film is bonded at the exterior side or the interior side,on the heat-ray absorbing performance and the thermal stresses is discussed.It is found that the alternative patch side has no effect on the heat-ray absorbing performance and that the patch side is recommended to be interior side from a view point of decreasing thermal stresses against the heat crack of glasses.展开更多
文摘Heat-ray absorbing sheet glass can decrease electric energy used for air-conditioning by controling the incoming heat-ray through windows into the rooms.On the other hand,the glasses increase the temperature and sometimes yield heat cracks by thermal stresses.It is important to know the state of thermal stress accurately in order to develop heat-ray absorbing sheet glasses with higher performance and without heat cracks.A conventional design manual at field site treats the steady state and the thermal boundary condition that all heat-rays are absorbed at glass surface.In this paper,it is assumed that the heat-ray is absorbed over all the plate thickness.The idea of the local absorptibity per unit length is introduced.The modeling of internal heat absorbing process is proposed.It can explain well that the total absorptivity depends on the plate thickness.The temperature and the thermal stresses are calculated and discussed.Sudden weather changes such as rain and/or wind after the glass is heated to be steady state are also discussed.Those weather changes are treated with the change of amount of absorbed heat-ray and/or the change of heat transfer coefficient between the glass surface and the outside atmosphere.
文摘Heat-ray absorbing film is used to be bonded on the existing sheet glasses of the windows.It is effective for air-conditioning energy saving against the global warming,because it absorbs heat-ray in the thin film and decreases the incoming heat-ray into the room.On the other hand,the sheet glasses increase the temperature at the surface which the sheet is bonded and sometimes yield heat cracks by thermal stresses.It is important to know the state of thermal stresses accurately in order to develop the heat-ray absorbing film with higher performance and without heat cracks.In this paper,the analysis model is treated as the two-layer plate of the conventional soda sheet glass and the heat-ray absorbing film with different absorptivities.The unsteady temperature and thermal stresses are analyzed and calculated numerically.The influence of the patch side,which the heat-ray absorbing film is bonded at the exterior side or the interior side,on the heat-ray absorbing performance and the thermal stresses is discussed.It is found that the alternative patch side has no effect on the heat-ray absorbing performance and that the patch side is recommended to be interior side from a view point of decreasing thermal stresses against the heat crack of glasses.
