天空辐射制冷规模化应用对我国建筑的减碳作用研究

Large-scale Application of Radiative Sky Cooling in Buildings for Carbon Emission Reduction

建筑的节能和可再生能源利用是实现碳达峰、碳中和目标的关键一步。天空辐射制冷作为无需额外能耗、无需制冷剂的制冷技术,对于实现建筑节能、降低碳排放具有重要意义。为此,本文研究了天空辐射制冷技术应用于我国既有建筑后的减碳作用预期,即降低建筑运行阶段碳排放的潜力。以统计年鉴为依据,获得目前我国建筑总存量面积及各省不同建筑类型存量面积。对9种典型建筑类型分别按节能标准建模,并在我国各省分别选取气象站的典型气象年数据,利用建筑能耗模拟工具EnergyPlus计算获得各省不同建筑类型在建筑运行阶段的碳排放基准值及应用天空辐射制冷技术后的减碳量、减碳率,其中居住建筑和工业建筑具有较高的平均减碳率。分析了应用后减碳率的空间分布,结果表明:按气候区划分的平均减碳率为严寒地区4.92%,寒冷地区8.11%,夏热冬冷地区10.71%,夏热冬暖地区10.92%,温和地区16.77%。综合全国年总减碳量可达2.30亿t CO_(2),占建筑运行碳排放的10.90%,占能源总碳排放的2.39%,对于我国实现双碳战略目标的预期贡献巨大。

Energy saving and renewable energy utilization in buildings are key to achieving carbon neutrality in China.Radiative sky cooling,as a passive cooling technology that requires no external energy input nor refrigerants,has a significant impact on increasing energy efficiency and reducing carbon emissions in buildings.To this end,in this study,the carbon emission reduction that can be achieved if passive radiative cooling technology is applied to existing buildings in China,especially in the operational phase,was explored.The current total building area and the stock area by building type in different provinces were obtained from the Statistical Yearbook.Nine building types were modeled according to energy efficiency standards,and weather data from typical meteorological years were selected for each province.With these inputs,the baseline carbon emissions during the operational phase of each building type in each province,as well as the amount and rate of carbon emission reduction after the large-scale application of radiative sky cooling,were obtained via simulations using the building energy consumption software EnergyPlus.Regarding the building type,residential and industrial buildings were found to have higher carbon reduction rates.The spatial distribution of the carbon reduction rate in China was also analyzed.The average carbon emission reduction rate in severely cold regions was 4.92%,whereas the rates were 8.11%,10.71%,10.92%,and 16.77%in cold regions,hot summer cold winter regions,hot summer warm winter regions,and mild regions,respectively.The total annual carbon reduction was calculated to be 230 million t of CO_(2),accounting for 10.90%of the building operation carbon emissions and 2.39%of the total energy carbon emissions.Thus,radiative sky cooling can be a significant contributor to achieving“carbon peaking”and“carbon neutrality”goals in China.