Solar Energy Resource Evaluation And Actual Heat Gains Of Roof And Southern Wall In Jiangxi Province

With the increasing demand for indoor comfort,the total energy consumption in China's buildings has been rising year after year.The air-conditioning energy consumption accounts for a large proportion of the total energy consumption of the buildings.The vast majority of building energy mainly comes from the fossil energy,such as coal,oil.The development and utilization of solar energy resources will reduce people's dependence on fossil energy.Relatively,the solar energy resource in Jiangxi province is rich in China,but the distribution of the resource is different in Jiangxi area.The proper development and use of the solar energy requires a correct and comprehensive understanding of the distribution characteristics of solar energy resource in Jiangxi.This paper aims to make a comprehensive and depth evaluation of the solar energy resources in Jiangxi Province.The suggestions for the passive use of solar energy are given considering the solar energy characteristics in the area.Meanwhile,the changes in the temperature and heat flux of the roof after the solar energy absorption are given.The paper evaluates the solar irradiation,stability and direct ratio in detail in Jiangxi province,adoptting the latest GB/T31155-2014(solar resource level and total radiation)solar energy resource evaluation method,using the meteorological data in the Chinese Meteorological Web and the standard meteorological data for construction.The monthly and annual averages of the solar irradiation and stability in all counties in Jiangxi and the direct ratio of the 10 representative counties are evaluated.The results indicate that solar energy resources are relatively abundant in Jiangxi.The monthly irradiation changes periodically and continuously.In summer the monthly average solar radiation reaches the maximum compared with other provinces in China.The solar radiation in mountainous regions such as Jinggangshan is relatively small.Most of the zones of the Jiangxi province are in B grade in the stability and under 0.55 in the direct ratio,which are in a moderate level in China.A house model is created based on the typical days' meteorological data in January,March,May,July,September and November of Nanchang in the past 30 years.Numerical simulation method is utilized to study the dynamical heat transfer process of the roof.Meanwhile,the average value of the temperature in every time period and the heat transfer flux in every hour of the outer surface are analyzed.The total net solar heat gains on typical meteorological days are studied based on the simulation.According to the total net solar heat gains of the roof,the suggestions of the passive use of solar energy in buildings are provided.The study of the paper provides theory gist and design guidance for building energy efficiency in Jiangxi Province.