Recently,large and thin glass substrates are transported by air film conveyors to reduce surface damage.On the production line,the glass substrates are desired to be transported flatly on the conveyor to ensure the qu...Recently,large and thin glass substrates are transported by air film conveyors to reduce surface damage.On the production line,the glass substrates are desired to be transported flatly on the conveyor to ensure the quality inspection.A method by feedbacking film pressure to the theoretical model is proposed for estimation of the deformation of the glass sheet,and the validity of the method is theoretically and experimentally verified.First,a theoretical model including the flow behavior through a porous-walled gap is established,and the film pressure distribution can be predicted by solving the model.Then,an experimental setup that can simultaneously measure the film pressure and the flatness of the glass sheet is established,and,the validity of the model is verified experimentally.Next,with the pressure points at the grooves as the boundary and the pressure points at the flange area as the feedback,an algorithm is applied to shape the one-dimensional deformation at the centerlines in accordance with a quadratic curve.Furthermore,two-dimensional deformation of the glass sheet can then be estimated by an interpolation operation.Comparisons of the calculated results with the experimental data verify the effectiveness of the estimating method.展开更多
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
基金This study was supported by the Natural Science Foundation of Jiangsu Province(Grant No.BK20181467)the National Natural Science Foundation of China(Grant No.51675247).
文摘Recently,large and thin glass substrates are transported by air film conveyors to reduce surface damage.On the production line,the glass substrates are desired to be transported flatly on the conveyor to ensure the quality inspection.A method by feedbacking film pressure to the theoretical model is proposed for estimation of the deformation of the glass sheet,and the validity of the method is theoretically and experimentally verified.First,a theoretical model including the flow behavior through a porous-walled gap is established,and the film pressure distribution can be predicted by solving the model.Then,an experimental setup that can simultaneously measure the film pressure and the flatness of the glass sheet is established,and,the validity of the model is verified experimentally.Next,with the pressure points at the grooves as the boundary and the pressure points at the flange area as the feedback,an algorithm is applied to shape the one-dimensional deformation at the centerlines in accordance with a quadratic curve.Furthermore,two-dimensional deformation of the glass sheet can then be estimated by an interpolation operation.Comparisons of the calculated results with the experimental data verify the effectiveness of the estimating method.
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.
