Research On Energy-saving Reconstruction Of Existing Residential Building Envelope In Jiangxi Under The Background Of "Double Carbon"

The goals of "carbon peak" and "carbon neutrality" is working hard to achieve in our country.However,the construction field,as a key industry of energy consumption,is facing arduous pressure on energy conservation and emission reduction.The acceleration of urbanization and the increase in the number of existing buildings have led to an annual increase in energy consumption in building operations,which has also resulted in a large amount of greenhouse gas emissions.In this context,it is of great significance to explore the methods on energy-saving renovation of existing buildings,which can not only improve the durability and use value of buildings,but also play an active role in energy conservation and emission reduction,and optimize the living environment.Since the promulgation of China’s first energy-saving design standard for nonheating areas 22 years ago,there are still a considerable number of non-energy-efficient buildings in Jiangxi province.Many early external wall insulation buildings also face the problem for renovation.The energy-saving renovation of existing buildings has been included in the local government’s work plan.After the implementation of the current national energy-saving standard,the energy-saving renovation standards for existing buildings have also been raised.Due to various objective factors,the scope of energy-saving renovation in existing residential buildings is limited.It is unlikely to involve the renovation of indoor air conditioning and heating systems.The building envelope structure has a significant impact on the operational energy consumption of buildings,but it cannot be completely overhauled.Therefore,the energy-saving renovation of residential buildings in Jiangxi Province is managed by statistics on completed building areas and household numbers.Referring to the energy-saving policies of neighboring provinces,it is expected that the energy-saving standards for buildings in Jiangxi Province will be further improved.The urgency and importance of upgrading the energy-saving renovation of existing residential buildings are selfevident.This paper takes a building with an early external wall insulation envelope structure as the research object and conducts preliminary energy-saving research in the region.The basic work includes thermodynamic modeling,energy consumption simulation,design comparison,etc.Based on the current energy-saving standards,the paper fully explores the potential for energy-saving and carbon reduction in existing residential building envelope structures.By analyzing the energy-saving effects of different building envelope structures on individual parts and then conducting a hierarchical association from local to global,the paper uses orthogonal experimental methods to combine various part renovation plans for energy consumption simulation,economic and carbon emissions analysis to find the best way to maximize benefits.Linear regression algorithms are used to analyze the factors that affect building carbon emissions,providing reference for the energy-saving renovation of existing residential buildings in Jiangxi Province.Considering different factors such as the small impact of energy-saving retrofits on residents,this research has drawn the following conclusions:(1)In the energy-saving upgrading and renovation scheme of existing residential buildings,the actual situation of the building should be combined.Meanwhile,the original building structure and structural form should be protected and utilized as much as possible.(2)The light-transmitting enclosure structure has the greatest impact on the energy consumption,economy,and carbon emissions of building enclosure energy-saving renovation.The single-layer external windows are transformed into double-layer windows.The proportion of glass windows is reduced,and the thermal performance of the entire window is improved.Measures such as airtightness and airtightness are better choices.(3)Without considering the renovation and updating of air-conditioning system,lighting and other equipment,by taking economical and reasonable building envelope renovation measures,the energy-saving rate of the renovated building can reach about62%,and the carbon emission can be reduced by more than 16%.(4)Among the various influencing factors of urban buildings in Jiangxi region,the air-conditioning degree days CDD26 and altitude are more sensitive to the carbon emission reduction of building operation.There is a negative correlation between altitude and carbon emissions reduction,with a correlation value of-0.45;The airconditioning degree days CDD26 is positively correlated with carbon emissions reduction,with a correlation value of 0.31.