Research On Energy-saving Renovation Technology Of Enclosure Structure Of Existing Office Buildings In Changsha Area

In our country,building energy consumption accounts for about 30% of the total energy consumption,and increases year by year,gradually becoming the region with the largest energy consumption.In building energy consumption,the existing office buildings are the region with the most serious energy consumption,so energy-saving work in this field is urgent.Changsha is a hot summer and cold winter area.The thermal performance of the envelope structure of office buildings directly determines the indoor thermal environment and the comfort of users.It is an important factor to be considered in energy-saving renovation.Nowadays,single energy-saving technology of enclosure structure has been very mature,but it is not necessarily energy-saving through mass technology stacking,even if energy-saving is achieved,it will lead to uneconomical.Therefore,this paper takes office buildings as the research object,aiming at finding the optimal comprehensive renovation scheme of the envelope structure of office buildings in Changsha area,and providing a design method for energy-saving renovation of envelope structure in Changsha area.The first part is to investigate the envelope structure of existing office buildings in Changsha area,analyze the structural characteristics of envelope structure in different years and calculate its thermal performance.The present situation of envelope structure in Changsha area is obtained,which lays a foundation for the follow-up study.The second part: According to the present situation of the envelope structure in different years,the commonly used transformation technology of the envelope structure in Changsha area is put forward,and the applicability of each technology is summarized,which provides a theoretical basis for the follow-up study.The third part: Build the basic model of energy consumption simulation,use the energy consumption simulation software Design Builder to analyze the energy saving rate of each envelope structure after transformation,and get the importance of the impact of various envelope structure transformation on the overall energy consumption as follows: outer window > shade > outer wall > roof.Then the economic analysis is carried out separately,and the results show that the optimum thickness of EPS for exterior wall modification is 50 mm;the optimum thickness of XPS for roof modification is 60 mm;the energy-saving effect and economy of low-E hollow glass window for exterior window modification are the best;and the effect of shading modification is the best.The fourth part:: According to the present situation of the envelope structure of office buildings in Changsha,the existing office buildings that need comprehensive renovation are divided into: all types of renovation,types of non-renovation of external walls and types of non-renovation of roof.Then,the orthogonal test scheme is designed separately,and the single technology with better economy is optimized and combined.Through the method of weighing and judging the envelope structure,the existing office buildings that need comprehensive renovation are screened out to meet the The comprehensive reform plan of Hunan Province's current energy-saving standard.Finally,the economic analysis is carried out separately,and the optimal comprehensive transformation schemes of various types of transformation are obtained.Finally,through the example verification,I hope to provide a valuable reference for the energy-saving renovation of the envelope structure of office buildings in Changsha area,and promote the energy-saving renovation of existing buildings in this area.