Environmental-economic Evaluation Of Building Life Cycle Based On Carbon Reduction Technologies

In recent years,more and more phenomena have shown that global climate change has posed a major threat to human society.The Intergovernmental Panel on Climate Change(IPCC)pointed out that only by achieving net-zero carbon emissions on a global scale in the mid-21 st century can global temperature rise be effectively controlled and the extreme harm caused by climate change be mitigated.In order to cope with the huge challenges brought by climate change,China proposed in 2020 the goal of "achieving carbon peak by 2030 and carbon neutrality by 2060".As a key area of energy consumption and carbon emissions,the building sector urgently needs to adopt carbon reduction technologies to reduce carbon emissions so that it can reach a low-carbon or even zero-carbon level.However,the current evaluation of low-carbon buildings and carbon-reduction technologies is incomplete and insufficient.Therefore,based on the whole life cycle assessment theory of buildings,this thesis evaluates the environmental and economic performance of buildings by quantifying the carbon reduction capability and value of carbon reduction technologies.The research content and results of this thesis mainly include the following aspects:(1)Based on the theory of life cycle assessment(LCA),combined with the existing specifications and the characteristics of building activities at each stage,a life cycle carbon emission accounting model of building is established,and based on this model,the carbon emission reduction effect of the building is analyzed.By analyzing the incremental cost composition of low-carbon buildings after applying carbon reduction technologies,an incremental cost model for the whole life cycle of low-carbon buildings is established.Combining the carbon emission reduction at each stage of the building life cycle with carbon pricing,a low-carbon building full life cycle incremental benefit model is established,and the economics of the building after carbon emission reduction is evaluated according to the established building incremental cost-benefit ratio index.(2)Sixteen carbon reductions technologies covering five building carbon reduction categories,including embodied carbon reduction,direct carbon emission reduction,indirect carbon emission reduction,renewable energy utilization,and carbon offset,are identified through Cite Space and existing normative summaries according to the research on building carbon emission categories and the carbon neutral path of the building industry.Based on literature research and industry reports,the technical points of various carbon reduction technologies are expounded,and the carbon emission reduction and incremental cost calculation methods of the carbon reduction technologies are established.The carbon emission reduction rate index and the emission reduction value index are established to evaluate the environmental and economic aspects of carbon reduction technologies,respectively.(3)Combined with actual engineering cases,based on the above models and methods,the carbon emission reduction effect and incremental cost and benefit of the building as well as the performance indicators of various carbon reduction technologies after applying the carbon reduction technologies are analyzed.The results show that for the application of carbon reduction technology,photovoltaic power generation technology in operation stage,using recycled concrete technology and shortening transportation distance have the best environmental,economic and application degree respectively.For the case building,the carbon emission in the operation stage accounts for the largest proportion after the carbon emission accounting of the whole life cycle of the building,but the application of carbon reduction technology can make the case building achieve the purpose of low carbon,and it can achieve "zero carbon emission" at the end of the whole life cycle.At the same time,according to the incremental cost and carbon emission reduction of various carbon reduction technologies,the incremental cost and incremental benefit of the case building are calculated,and it is concluded that the incremental cost and incremental benefit generated in the operation stage are the highest,and the incremental benefit is far greater than the incremental cost.The incremental cost-benefit ratio of the final case building is 1.84,indicating that the solution of applying carbon reduction technology in buildings is economically feasible from the perspective of the whole life cycle.