| In recent years,glass curtain wall has been more and more widely used in buildings.Although glass curtain wall has the advantages of beautiful appearance and wide vision,some problems existing in glass curtain wall buildings have to be paid attention to: such as large cooling load in summer,large heating load in winter;When the solar radiation is large,some glass curtain wall buildings will glare,and the light comfort is low.Therefore,it is necessary to study the light adjusting method of glass curtain wall.On this basis,the research group put forward the Bimetal Automatic Light Adjusting Device(BALAD).The bimetal piece in the device is a laminated composite material formed by the bonding of two different metal materials,because the thermal expansion coefficient of the two metals is different,the curvature of the bimetallic sheet will change when the temperature changes,so as to change the solar ray transmittance of the device,and automatically adjust the indoor light and heat purpose.Our research group has completed the design of BALAD,and proved the feasibility of bimetallic light adjusting according to the experiment,and completed the analysis of the adjustment effect of BALAD on indoor photothermal environment in Beijing area.Through experimental tests and combined with simulation analysis,this paper analyzes the indoor heat gain of rooms using this device and traditional light adjusting mode in different cities,and analyzes the changes of indoor natural lighting in rooms using this device,and draws the following conclusions:(1)According to the experimental results,the internal temperature of the room using BALAD is generally lower than that of the control room,especially at the time of high solar radiation around noon,and the temperature difference can exceed 7℃.Therefore,the purpose of indoor temperature regulation can be realized through BALAD.(2)According to the simulation results,it can be seen that BALAD can effectively regulate indoor energy consumption and natural lighting.Taking Beijing as an example,the indoor heat gain in a room using BALAD reduces by 3%～18% in January,and by 200% in July,compared with that in a room with ordinary closed double-glazing.In August,the maximum illumination reduction of 0.75 m high level in the room where the device is located can exceed 25,000 Lux,and the number of moments with lighting level Ⅰ can increase by 31%.(3)The study shows that the material and the ratio of length to height of the bimetallic sheet have a great influence on the adjustment ability.In addition,BALAD was preliminarily optimized,and the applicability of BALAD was analyzed.Economic comparison of BALAD with electrochromic glass was made from three aspects: construction cost,service life,operation and maintenance cost.The results show that BALAD has certain economic performance.In this paper,the working principle of BALAD is introduced in detail,and the application effect of BALAD and traditional light adjusting method in cities with different meteorological zones is analyzed.The results show that BALAD can effectively reduce the indoor heat gain and significantly reduce the indoor discomfort glare index,which has a high use value in most areas of China.The research results of this paper can provide reference for BALAD’s subsequent improvement research. |
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