Research On The Performance Of Trapezoidal Concentrating And Thermal Storage Dimming Device And Its Influence On Indoor Thermal Environment

For buildings with relatively large window walls,due to the lack of effective shading measures at noon,excessive sunlight irradiates the room,which will inevitably lead to a series of problems such as glare and excessive indoor temperature.Therefore,this problem can be effectively solved by changing the transmittance of the transparent envelope structure of the building.The main methods of change are active and passive.Although the active adjustment method currently used in China can solve this problem,its initial investment is relatively high and the investment recovery period is long,which is not conducive to large-scale promotion.Therefore,this paper proposes a passive trapezoidal light-concentrating and heat-storing dimming device based on CPC(compound parabolic concentrator)theory,which combines the adjustment of transmittance with heat storage to achieve the effect of one plus one greater than two.This article researches its performance and indoor influence from two parts of practice and theory.Experiments are carried out on the trapezoidal solid light-concentrating heatstorage dimming device.The change curve of the sun’s outdoor illumination and radiation intensity generally shows the characteristics of first increasing and then decreasing,and it shows that the curve of the steeper simulation box outside illumination and radiation intensity is transformed into a relatively smooth simulation box illumination and radiation intensity The phenomenon of changing curves.The experimental results show that the equipment has the functions of dimming and focusing.During the experiment,the water temperature in the trapezoidal cavity first increased and then decreased.At the end of the experiment,there was no obvious difference with the water temperature of the water tank,but it was always higher than the indoor temperature.The experimental results show that the equipment has a heat collection function.Optical simulations show that as the incident angle of light gradually increases,the transmittance of the device gradually increases.When the light incident angle is 0°,the transmittance of the device is only 1%,and when the light incident angle is more than 40°,the transmittance of the device is above 80%.Theoretical analysis shows that the equipment has the functions of dimming and focusing.In addition,the theoretical calculation shows that the heat collection efficiency of the device is around 10%,which can effectively reduce the indoor heat gain and reduce the air-conditioning load.The reduction ratio can reach 40% in the Beijing area.Theoretical analysis shows that the equipment has a heat collection function and can effectively regulate the heat gain entering the room.