| Construction industry consumes a lot of energy.It is of great important to reduce building energy consumption by energy-efficient retrofitting of building facades.Green facade system can provide additional insulation for the building to reduce energy consumption.It is of great important to use green facade system to achieve building carbon neutrality.In this paper,the annual building energy consumption and comfort of green facade system in hot summer and cold winter zone are systematically studied.Firstly,through in-depth analysis of Energy Plus energy simulation software,a green facade system model considering evapotranspiration is established according to the green roof model,and a green facade system model without considering evapotranspiration is established according to the shading model.Secondly,the solution methods of green facade system model considering evapotranspiration and green facade system model without considering evapotranspiration are introduced.The green facade system model considering evapotranspiration is solved with MATLAB software based on the finite difference numerical method.The green facade system model without considering evapotranspiration is solved with shading module in Energy Plus based on the conduction transfer function coefficient method.Thirdly,the experimental test platform of green facade system is established for comparing and analyzing the thermal performance of green facade system and ordinary wall.The experimental results show that,after using the green facade system the external surface temperature and the internal surface temperature of the wall are reduced by 1.76℃ and 1.46℃ respectively.The accuracy of the green facade model considering evapotranspiration and the green facade model without considering evapotranspiration is verified according to the experimental results,and the verified results of two models are compared.The results show that: 1)the two models agree well with the experimental results;2)The accuracy of the green facade model considering evapotranspiration is slightly better than that of the green facade model without considering evapotranspiration,but the RMSE of the two models are close.Finally,taking Nanchang area as an example,the green facade model without considering evapotranspiration is used to analyze the thermal performance of the green facade system influenced by different leaf area index,different orientations and different seasons in hot summer and cold winter zone.The conclusions are as follows:1)It is conducive to indoor environment comfort and air conditioning energy saving when the green skin system is installed from May to September,while the effect is opposite in other months.2)The heat flux and PMV value of the room decreased with the increase of the leaf area index.With the further increase of the leaf area index,the influence on the heat flux and PMV value of the room decreases gradually.3)The importance of orientation affecting the thermal performance of the green facade system changes with time.In spring,the importance of each orientation are:West > East > North > South.In summer,the importance of each orientation are: West >South > East > north.In autumn the importance of each orientation are: West > South >East > North.4)The optimal configuration of the green facade system in hot summer and cold winter regions is LAI=4,and the orientation is west.Under this configuration,the heat transfer of the internal surface of the wall can be reduced by 56.6% in summer,and the PMV value can be reduced by 0.14 and 0.16 respectively in late spring and early autumn. |
