Study On Shading Design Of Teaching Building Outside Window In Chengdu Area

This paper mainly studies the optimal design of exterior shading form and size for different orientations of teaching buildings in Chengdu.Firstly,according to the size calculation formula of horizontal and vertical shading,the size calculation formulas of multi-layer horizontal shading,multi-layer inclined horizontal shading,multi-layer vertical shading and multi-layer inclined vertical shading are deduced.Based on the optimization design principle of energy saving,lighting and material saving,and on the basis of theoretical calculation of exterior shading size,numerical simulation method was adopted to further optimize exterior shading form and exterior shading component size.The main research results of this paper are as follows:(1)Of the two kinds of calculation under different shading outer shading form of the component size for simulation study,the results found that south to"full shade line"of the solar altitude Angle and azimuth Angle corresponding to calculate the external blinds size based on the extreme hot weather day outside of the solar altitude angles corresponding to calculate the shade size three times,energy consumption were similar,And meet the lighting requirements of teaching buildings in Chengdu area;The external shading size calculated by the sun height Angle and azimuth Angle corresponding to the"full shading line"in the east and west direction is smaller than that calculated by the sun height Angle corresponding to the"extreme high temperature day".Although the former has a slightly higher energy saving rate,it does not meet the lighting requirements of teaching buildings in Chengdu.Therefore,the size design optimization of shading components can be carried out according to the sun altitude Angle and azimuth Angle corresponding to extreme high temperature days in practical engineering.(2)The optimal shading design of the building in the south,east and west directions is simulated and studied.Considering the factors of energy consumption,lighting and material saving,the optimal shading method and size for different orientations are obtained.(1)Horizontal sunshade should be used for the outer window of the south-facing classroom.The size of the sunshade is 384mm horizontally picked out and 720mm at both ends.The energy rate is 1.01%when there is no external shading.(2)In the optimization design simulation of shading outside the windows of the east-facing classroom,the baffle shading is firstly adopted.Although the baffle shading can reduce the total energy consumption,its lighting coefficient and average illumination do not meet the lighting requirements of teaching buildings in Chengdu,so the baffle shading is not suitable for the east-facing classroom.When the number of horizontal visors is 3,the indoor energy consumption is relatively minimum on the premise of satisfying the lighting.However,the length of the horizontal visor is still large.By tilting the horizontal visor at a certain Angle,the size of the visor can be reduced,but it cannot meet the needs of indoor lighting.Finally,the external shading with multi-layer vertical sun visor is adopted.Considering the factors of lighting,energy consumption and material saving,the external shading with 8-layer vertical sun visor is adopted.The best shading is when the sun visor tilts 40°.at this time of indoor daylighting coefficient was 4.72%,the average intensity of illumination for the 565 lx,indoor cold consumption is 117.05 k Wh/m~2,heat consumption of 65.62 k Wh/m~2,indoor total energy consumption of 182.67 k Wh/m~2,relative without external blinds the energy-saving rate of3.58%.Therefore,the external window of the east facing classroom should adopt the external sun shading with 8 layers of vertical sun visors,with a tilt of 40°.The specific size is as follows:the overhanging length of the vertical sun visors is 426mm,and the spacing is 675mm.(3)In the optimization design simulation of shading outside the window of the west facing classroom,baffle shading is firstly adopted.Although baffle shading can reduce the total energy consumption,its lighting coefficient and average illumination do not meet the lighting requirements of teaching buildings in Chengdu,so baffle shading is not suitable for the west facing.Then,the external shading with multi-layer horizontal sunshade was adopted.When the external shading with five-layer horizontal sunshade was the best,the indoor lighting coefficient was 3.94%,the average illumination was 471lx,the indoor cooling consumption was 106.80k Wh/m~2,the heat consumption was 66.64k Wh/m~2,and the total indoor energy consumption was 173.44k Wh/m~2,and the energy saving rate was 2.66%compared with that without external shading.Therefore,the exterior shading of 5 layers of horizontal sun visors should be used for the exterior window of the western-facing classroom.The specific dimensions are as follows:the overhanging length of the horizontal board is 394mm,and the spacing of the sun visors is 480mm.The research in this paper can provide reference for the selection of shading forms and size optimization in practical engineering,which has certain engineering significance.