Study On Carbon Emissions Calculation And Carbon Eduction Strategy Of Urban Residential Life Cycle In Cold Areas

In recent years,global environmental degradation due to the sharp increase in carbon emissions has become the world's top environmental issue.According to UNEP,the construction industry consumes about 30-40% of the world's energy and emits almost 30% of the world's greenhouse gases,posing a huge environmental challenge.China's national contribution document on climate change,"Strengthening Climate Change Actions-China's National Independence Contribution" determines that carbon dioxide emissions peak in around 2030 and strives to reach peak as early as possible.The carbon dioxide emissions per unit of GDP are 60%-65 lower than in 2005.How to implement China's 60%~65% emission reduction commitments in the Paris Climate Change Agreement,and the construction industry accounts for more than 7% of GDP.Urban housing,as the largest construction type,has a huge impact on energy conservation and emission reduction in the construction sector.Therefore,the carbon emissions of urban residential life cycle around 2005 are measured,and the carbon emission characteristics of each stage of the life cycle are studied to establish a reference sample of carbon emissions of typical urban residential types in 2005,which is the current construction industry.Energy saving and carbon reduction provide benchmarking.Firstly,this study proposes to study the carbon emissions of buildings from the perspective of life cycle.On the basis of summarizing the relevant research on the whole life cycle stages of buildings at home and abroad,the whole life cycle of buildings is divided into planning and design stage,materialization stage,use and maintenance stage.The four stages of demolition and clean-up are based on aprocess-based life cycle inventory analysis method combined with a carbon emission factor method for building carbon emissions calculations.At the same time,the main carbon emission unit process of each stage of the whole life cycle of the building is defined,and on this basis,the carbon emission calculation model of the whole life cycle of the building is constructed.Secondly,this study analyzes the composition of the national residential construction in 2005,and selects the urban residential type with the largest proportion of residential construction in 2005.The urban residential building with high-rise reinforced concrete structure is the type of carbon reduction benchmark building,and A high-rise reinforced concrete residential building in Xi'an(C-B area)takes the life cycle carbon emission calculation as an example,and derives the full life cycle and carbon emissions of the house.Thirdly,the characteristics of carbon emissions in each stage of the life cycle of the case are analyzed,and the main influencing factors of carbon emissions in all stages of the life cycle are obtained.In the whole life cycle of the building,the carbon emissions in the maintenance phase accounted for about 87.88%,followed by the materialization phase(taking into account the recovery rate of building materials),the carbon emissions accounted for about 11.13%,and finally the demolition and cleanup phase was about0.98%;in the materialization stage,the carbon emissions in the building materials production phase accounted for about 95.20%;in the use and maintenance phase,the carbon emissions in the use phase due to heating energy consumption accounted for the largest proportion,59.10%,followed by the carbon emissions of the lighting 24%,the carbon emission caused by air conditioning refrigeration is 12%;in the demolition and cleanup stage,the carbon emissions generated by the dismantling equipment operation account for about 3.75% of this stage,and the carbon reduction caused by the recycling of waste building materials accounts for this stage.80.22% of carbon emissions,carbon emissions caused by transportation of waste building materials accounted for about5.08%,and the recovery rate of waste building materials is the main factor affecting carbon emissions at this stage.Finally,according to the analysis of the carbon emission of the benchmark building,the carbon reduction strategy of urban residential buildings in cold regions is proposed from all stages of the whole life cycle,and the case building is taken as an example to contribute to the emission reduction contribution of the carbon reduction strategy.According to the specific calculations,it is estimated that in the cold regions,taking Xi'an as an example,the key effective strategies for reducing the carbon emissions of urban residential life cycles are: 1)improving the efficiency of heating energy use;2)extending the service life of buildings;Use low-carbon energy to reduce electricity carbon emission factors;4)Improve thermal performance of enclosures;5)Use renewable energy;6)Reduce building shape factor;7)Use high recovery materials;8)Use high Performance building materials;9)use of energy-saving lamps;10)instead of demolishing in the form of building dismantling;...