Study On Energy-Saving Renovation Of Existing Residential Envelope Structure In Northern Anhui Province And Economic Analysis

The paper takes the 14th Five-Year Plan for building energy saving as the background,takes the exterior envelope of the old residential buildings in northern Anhui as the research object,carries out energy-saving renovation research on each component.The paper aims to find the best economic solution for the renovation of residential buildings in northern Anhui Province,and to provide some reference for the renovation of energy saving in this area.The first part of the thesis firstly elaborates and analyzes the current situation of domestic and foreign research and existing renovation technology,draws on previous renovation experience through reading a lot of books and literature and renovation cases,selects a reasonable form of envelope renovation,and lays a good theoretical foundation for the subsequent in-depth research work.In the second part,DeST is selected as the energy consumption simulation software,and the existing representative residential buildings in northern Anhui Province are modeled as the base model.The exterior wall,roof,exterior window heat transfer coefficient and exterior window shading coefficient were selected as the research objects,and the values of each individual factor were varied in a gradient by the control variable method to investigate the influence of each factor on the building load and energy saving rate.The sensitivity analysis was combined with the sensitivity analysis to analyze the influence of each factor to make the subsequent study more relevant.The third part focuses on the technical and economic analysis of the single exterior envelope structure in northern Anhui.Firstly,the modification form of each component is determined,then the heat transfer model of exterior walls and roofs in northern Anhui area is established by heating and cooling degree day method,and the economic hadness analysis model is established by combining the whole life cycle method to explore the best economic thickness of various commonly used insulation materials.At the same time,the life-cycle cost,net present value cost and payback period of various materials at their optimal thickness are solved.The economic retrofit of exterior windows is also based on various common materials,and the materials with different parameters are brought into the benchmark model of DeST to compare and analyze the various costs under different materials,so as to pave the way for the comprehensive solution retrofit of the subsequent study.The fourth part of the study was based on the results of the third part.Firstly,the facade,roof and exterior windows were selected as the test influencing factors,and the economic thickness of various materials was used as the level number for the test to carry out the orthogonal test design.Then,each test solution was brought into DeST software for simulation to find out the energy consumption of each solution,and the technical-economic and energy-saving analyses were conducted separately for the comprehensive retrofit solutions,and the best technical energy-saving and best technical-economic solutions were selected.The main results obtained in this study are as follows.（1）Simulation analysis of old residential buildings in Bengbu area by DeST software shows that:reducing the heat transfer coefficient of the exterior envelope can significantly reduce the energy consumption in the heating season and improve the overall energy saving rate of the building;reducing the shading coefficient of the exterior windows can significantly reduce the cooling energy consumption of the building in summer,but will lead to an increase in energy consumption in winter.（2）The sensitivity analysis method is used to derive the influence of envelope parameters on building energy consumption:for thermal load influence size:K_wall>K_window>SC>K_roof.For cold load influence size:SC>K_window>K_wall>K_roof.For total load influence size:K_wall>Kwindow>SC>Kroof.（3）The heat transfer model and the whole life cycle cost model for a single exterior envelope were developed using the heating and cooling degree-day method and the P₁-P₂economic theory,respectively.It is concluded that the present value of life-cycle cost is lowest for exterior walls and roofs with 42.04 mm and 48.1 mm XPS panels,respectively;the present value of life-cycle cost is lowest for exterior windows with medium-permeable Low-E windows.（4）The best comprehensive technical and economic scheme was designed through orthog onal tests:the exterior walls were insulated with 55mm EPS panels;the roofs were inverted w ith 50mm XPS panels;and the exterior windows were replaced with low-transmittance Low-E insulating glass broken-bridge aluminum windows.And the comprehensive plan can increase the energy-saving rate of the old houses in northern Anhui by more than 40%after calculation.Figure [forty-six] Table [thirty-eight] Reference [eighty-five]...