Research On Energy Matching Characteristics Between Zero Energy Residential Building And Photovoltaic Systems In China

Zero energy residential buildings have received widespread attention from the society due to their superior energy saving performance.To achieve the balance of energy production and demand in residential buildings,the application of renewable energy is essential.The photovoltaic system is suitable because of its high energy grade and wide application range.However,the research on building photovoltaic systems in China has been carried out late,and the energy consumption of zero energy residential buildings in different climate areas has space-time and capacity mismatches with the production capacity of photovoltaic systems;the hourly calculation method of photovoltaic has a large amount of calculation and requires high basic data;the calculation method of the contribution rate of the building photovoltaic system has not been established;the problem of insufficient utilization of the residual heat of photovoltaic energy in zero energy residential buildings has caused certain obstacles to the promotion and application of the building photovoltaic system in China.The related researches are summarized below:First of all,this paper constructs a monthly typical daily meteorological parameter calculation method based on dynamic weighted average processing for the low load characteristics of zero energy residential buildings.It uses the dynamic weighted average method to process hourly meteorological data to obtain monthly solar radiation data,and finally obtains monthly photovoltaic power generation.This calculation method comprehensively considers the monthly meteorological data of each month toeliminate the influence of the uncertainty of weather factors on the calculation results.Compared with the original calculation method,the accuracy of the monthly photovoltaic calculation method based on typical days is improved by 5%~10%.Secondly,for grid-connected photovoltaic systems,based on the climatic conditions in each climate zone of China,a calculation method for the matching contribution rate of photovoltaic systems that is affected by multiple factors such as installation angle,orientation,photovoltaic conversion efficiency,and photovoltaic volume ratio of building photovoltaic modules is proposed.Maximum photovoltaic contribution rate of zero-energy residential buildings in the climate zone.Studies have shown that typical residential buildings in southwestern China are the easiest to achieve zero energy consumption.When using photovoltaic modules with high photovoltaic conversion efficiency(20%),the comprehensive value of building energy consumption in all parts of China can be lower than 15 kWh/m2 a.The photovoltaic contribution rate of typical high-rise residential buildings on the Qinghai-Tibet and Yungui plateau can reach 168% and 130%.It is only possible to balance energy production and demand in low-rise and middle-rise buildings in southeastern China.The average deviation of the data obtained by using the grid-connected photovoltaic system contribution rate calculation method is 5.5%,the calculation method has good applicability to different regions.Furthermore,for off-grid photovoltaic systems,zero energy residential building photovoltaic system optimization method and matching method based on monthly production capacity and energy matching are proposed,which provide a technical foundation for the design of off-grid photovoltaic systems for zero energy residential building.In low-rise buildings,rooftop photovoltaic systems in all regions can meet70% of the building’s energy needs.Among middle-rise buildings,the east-west facade photovoltaic system of typical residential buildings in southern China is superior to the south facade photovoltaic system,and its photovoltaic contribution rate is increased by5%~10%.And after 0.17,it is possible to achieve zero energy consumption.High-rise buildings are recommended to use a combination of roof + south facade + east-west facade.When the PV volume ratio exceeds 0.1,the advantages of the east-west facade photovoltaic system in the Yunnan-Guizhou Plateau area relative to the south facadegradually appear.Even on the Qinghai-Tibet Plateau,it is only possible to achieve zero-energy buildings after the PV volume ratio reaches at least 0.14.When heating energy consumption/cooling energy consumption dominates,the roof photovoltaic system’s inclination should be slightly higher/lower than the local latitude,and the layout of the facade photovoltaic system should be mainly south facade/west facade.Finally,according to the heat production characteristics of the photovoltaic system,the temperature variation law of the back surface of the south facade photovoltaic system in different climate regions in winter is determined,which provides the basic conditions for the utilization of photovoltaic residual heat in the heating of zero energy residential buildings.The results of the study show that,except for the northeast region,the temperature of the back surface of the photovoltaic system on the south facade reaches its peak in winter.Even in the severely cold areas in the north,when the outdoor temperature is-10℃,the temperature of the back surface of the photovoltaic system remains at 20℃.