Research On Energy Saving Of Building Envelope Structure In Nanjing Area Based On DeST Simulation

With the acceleration of globalization and the continuous development of society,the problem of energy shortage has been paid more and more attention.In China,building energy consumption increases year by year.With the improvement of the material level,people began to pursue a healthy and comfortable living environment,so the call for energy conservation and emission reduction in buildings is getting louder and louder.In view of the large stock of existing residential buildings and taking residential buildings in Nanjing area as an example,this paper studies the influence of the change of main parameters of envelope structure on building load and gives an appropriate energy saving renovation plan.This paper compares and analyzes the common energy consumption simulation software at home and abroad,summarizes the characteristics of each energy consumption simulation software,and introduces the methods and theoretical knowledge to be used in the later period to study building energy conservation.Through comparative analysis of several energy-saving renovation methods of exterior wall,roof and exterior window,the renovation methods of envelope structure suitable for Nanjing area are as follows:external insulation of exterior wall,inverted roof and replacement method of exterior window.The influence of wall-wall heat transfer coefficient(K exterior wall),roof heat transfer coefficient(K roof),exterior window heat transfer coefficient(K exterior window)and solar heat gain coefficient(SHGC)of exterior window on the accumulated load of the building throughout the year was studied by means of DesT-H energy consumption simulation software.The study shows that there is a linear relationship between these four parameters and each load and the total energy saving rate of the building,which can be used to quantitatively predict the influence of the change of building envelope parameters on each load index.Based on the thermal parameters of existing residential buildings in Nanjing and their corresponding energy consumption values,K exterior walls,K roof,K exterior Windows and SHGC were taken as input parameters,and the annual cold and heat load indexes and the annual total load indexes of buildings were taken as output parameters to study the sensitivity coefficient.The influential factors are taken as the key objects of building energy conservation research.The factors affecting the building envelope were determined as three factors:the thickness of exterior wall insulation layer,the thickness of roof insulation layer and the material of exterior window.By means of orthogonal test,the three factors were tested in multi-level orthogonal test,and the difference analysis was carried out to determine the significance of each factor on the total building load.To introduce the concept of cost effectiveness and static investment payback period,by calculating the cost effectiveness of different schemes and static investment payback period,choose the higher cost effectiveness,the shorter the payback period of static solution as the optimal energy saving retrofit scheme:exterior wall thermal insulation material is 60 mmeps board,roof insulation materials for 80 MMXPS board,outside the window choose ordinary three bo(ordinary insulating+single glass)outside the window.The cost-efficiency ratio of the scheme is 2.22,the static investment payback period is 6.33 years,and the energy saving rate is 32.24%.Fig[40]table[29]reference[62]...