Optimal Design Of Solar Energy Application For Commercial Buildings In High-density Cities Of The Pearl River Delta Based On Carbon Audit

In recent years,the expansion of the scale of the construction industry has led to more energy consumption and carbon emission.The carbon emission of the global construction industry account for 28% of the total carbon emission.In order to achieve the goals of carbon peak in 2030 and carbon neutralization in 2060,it is urgent to reduce the carbon emission in buildings.The solar energy application technology in buildings is one of the promising choices to achieve energy conservation and emission reduction.At present,most studies only focus on a single solar energy application system.Taking the solar energy application technology and air conditioning system in buildings comprehensively evaluated from the perspective of the whole life period,it may be conducive to achieve energy conservation and emission reduction to a greater extent.First,based on the whole life cycle assessment theory,the solar hot water system,photovoltaic power generation system and air conditioning system in the building were divided into production stage,construction stage,operation stage and disposal stage.The carbon emission range and the carbon emission mathematical calculation model were determined.Second,with literature review and numerical simulation methods,the specific information of typical commercial buildings in the Pearl River Delta,the best arrangement of solar panels and the suitable air conditioning system scheme were determined.Third,using solar collector/photovoltaic panel area ratio,building shape coefficient and air conditioning system scheme as variables,the building performance simulation of office,hotel and mall under different scenarios was carried out.Finally,the energy consumption,carbon emission and carbon payback time of the building system were analyzed quantitatively.The conclusions of the above research can be summarized as follows:(1)For high-density urban commercial buildings in the Pearl River Delta,solar collectors and photovoltaic panels are suitable to be arranged on the roof.The best installation direction is toward south and the inclination angle is 21°.For office and hotel,the minimum installation spacing between panels is 1.1m,while for mall,the minimum installation spacing is 2.1m.(2)From the perspective of life cycle carbon emission,for office and hotel,the environmental benefits of using solar water heaters are significantly better than that of using photovoltaic power generation systems,but for mall,arranging more photovoltaic panels is conducive to reducing building carbon emission.On the premise of changing the area ratio of collector and photovoltaic panel by 10%,for office and hotel,when the collector area accounts for 100% of the total layout area,the carbon payback period of the solar system is the shortest and the carbon emission is reduced the most.For mall,when the collector area accounts for 30% of the total layout area and the photovoltaic panel area accounts for 70%,the carbon payback period of the solar system is the shortest.When the collector area accounts for 10% of the total layout area and the photovoltaic panel area accounts for 90%,the carbon emission is reduced the most.(3)When a building is equipped with a solar water heater,the carbon payback period of the solar system is closely related to the hot water demand of the building.When the area of the collector is the same,the larger the hot water consumption on the demand side will help to shorten the carbon payback time of the system.For office,when the building shape coefficient is small and the number of floors is large,arranging more solar collectors instead of photovoltaic panels can make the solar system achieve a shorter carbon payback period.For hotel,the demand for hot water is large,and the energy-saving benefits brought by the arrangement of heat collectors on the building roof are larger than those of photovoltaic panels.The roof of mall has more space,the arrangement of solar collectors and photovoltaic panels can make the solar system achieve shorter carbon payback periods.(4)The optimal scheme of air conditioning system should not only consider the carbon emission caused by system construction,but also involve the carbon emission caused by energy consumption during system operation.When the system runs to the end of its life,for office,the combined use of chilled ceiling + fresh air system and fan coil + fresh air system have the lowest carbon emission of 14975t;for hotel,the combined use of fan coil + fresh air system is the most suitable,which has a carbon emission of 5899t;for mall,The combined use of chilled ceiling + fresh air system and constant air volume system have the lowest carbon emission,which is 13523 t.