Research On Comprehensive Assessment Method Of Life Cycle Carbon Emission And Economics Of Building Components

With the rapid development of the economy,society and cities,the global resources and energy are depleting,and the environment is deteriorating,which has threatened the development of mankind and the survival of future generations.How to coordinate the relationship between economic development and climate change is a hot spot in the world.As a pillar industry for energy consumption and economic development,how to carry out sustainable development is a problem that we need to study for a long time.Because the building not only directly or indirectly consumes various energy sources,resources,and pollutants during the operation phase,it is also in the stage of building materials construction,construction and demolition.Therefore,to properly select the architectural design plan and correctly guide the sustainable development of the building,it is necessary to quantitatively evaluate the environmental and economic comprehensive performance of the entire life cycle of the building.In this study,building components are used as research objects.Through the background cognition research and the analysis of the status quo of domestic and foreign research,a structured review of the literature on the life cycle assessment,carbon emissions,economic evaluation and comprehensive evaluation methods for building materials,buildings and building components.The main work of this study is as follows:Firstly,this study determines the system boundary,functional unit and environmental impact of building components by comparing the existing comprehensive evaluation methods of building and building components.With reference to the process-based life cycleevaluation method,the building components are proposed.The carbon emission and cost accounting models of each stage of the life cycle,and the carbon emission reduction price in the environmental load value method,the comprehensive evaluation method model of building components is proposed,and the comprehensive cost increment is used as the comprehensive evaluation index.Secondly,a comprehensive evaluation method is used to conduct a case study on the roofs,walls and windows of an office building in Xi'an.Among them,there are 64 sets of roof construction schemes,134 wall construction schemes,and 3 window construction schemes.Contrast analysis of carbon emission increment,cost increment and comprehensive cost increment at different stages of the life cycle,and then using Excel software for fitting analysis,to obtain the insulation thickness of each group of construction schemes(wall self-insulation block thickness)And a functional expression of the combined cost increment and the best insulation thickness(optimum self-insulating block thickness).Among them,in the roofing members,the optimum thickness of EPS is 160 mm,the optimum thickness of XPS is 145 mm,the optimum thickness of polyurethane is 95 mm,and the optimum thickness of rock wool board is 145 mm,in the wall members,The optimum thickness of EPS in group,??,?,? and ? were 180 mm,185mm,185 mm and 185 mm respectively.The optimum thickness of rock wool board in group,?,?,? and ? was 150 mm,155mm,160 mm,165mm respectively.The optimum thickness of the ? group aerated concrete self-insulating block is 455 mm,which provides guidance for the rational selection of economical low-carbon building materials and optimized design.Finally,the uncertain factors affecting the comprehensive evaluation results of building components,such as electricity price,carbon emission reduction price,material carbon footprint factor,material service life and unit price,are analyzed,and sensitivity is applied to the construction scheme corresponding to energy conservation standards and ultra-low energy consumption standards.Analysis,respectively,obtain the sensitivity coefficient of different influencing factors of each group of programs.The absolute values of the sensitivity coefficients of various factors are: electricity price,carbon emission reduction price,age of insulation materials,unit price of insulation materials,and carbon footprint factor of insulation materials.Then,from the perspective of component material stage,building use stage and component demolition stage,the strategies of improving the comprehensiveperformance of building components and buildings are discussed,which provides guidance for architects to design the project.