Heating Carbon Emission And System Improvement For Rural Building Of Beijing

Northern rural heating is an important part of energy consumption and carbon emission in China.As a form of building energy system,the calculation method of building energy system carbon emission must be defined to evaluate its carbon emission.Therefore,this paper through further study of carbon emissions calculation methods of home and abroad,combines with the characteristics of building energy systems,bases on our country existing carbon emission standards,analyzes seven heating system in Beijing rural areas,include coal-fired boiler,direct electric heating,storage electric heating,gas-fired heating boiler and so on,gives energy system improvement suggestions from the perspective of carbon emission.The specific work is as follows:(1)Deeply study the domestic and foreign status of carbon emission calculation,including carbon emission evaluation methods,technical routes and case studies.Determines LCA as the building energy system carbon emission evaluation method.Based on the theory of life cycle assessment,determine the boundaries of building energy system,the whole life cycle of the system is divided into equipment production,installation,operation maintenance and removal treatment stages,respectively according to the principle of carbon emissions coefficient method is established at various stages of the mathematic model of energy consumption and carbon emissions.Analyzes the influence of four factors on carbon emission calculation of heating system,including energy structure,equipment life,equipment efficiency and regional location.(2)Analyzes the current situation of winter heating in rural areas of Beijing,including the building year,building area,basic information of enclosure structure and main heating modes in winter of typical Beijing rural houses.In view of the actual situation of clean heating in rural areas of Beijing,this paper takes gas-fired furnace,direct electric heating,regenerative electric heater,low-ambient temperature air source heat pump blower,and low-ambient temperature air source heat pump hot water heater as the research object,and takes coal-fired boiler as the reference object.(3)Analyzes the carbon emission ratio of different heating schemes at different stages and the influence of terminal form on the carbon emission of heating system,compares the carbon emission of heating system under different thermal performance of envelope,and makes economic analysis.The results is as follows,for all heating schemes,the largest proportion of carbon emissions is the operating stage,so operating stage is the key to reduce the carbon emissions of the heating system;storage electric heating and carbon fiber electric heater unit system have the highest heat emissions,compared to coal boiler is higher than 13.8% and 16.5% respectively.Gas-fired heating boiler,low temperature air source heat pump heat fan,low temperature air source heat pump hot water machine heat emissions decreased 72.0%,49.7%,and 50.2% respectively to coal-fired boiler unit system.Using radiant floor as the end of the air source heat pump hot water machine with low ambient temperature can reduce the carbon emission by 7.7% compared with the heat sink unit system.Compared with insulated rural houses,the total lifetime carbon emission of different heating schemes of non-insulated rural houses can be up to 2.01 times higher,so the improvement of building energy efficiency can significantly reduce the carbon emission of the energy system.