利用采暖/制冷度日分析建筑能耗变化的适用性评估

Applicability Evaluation of Cooling/Heating Degree-Days in Analyzing Building Energy Consumption Changes

采暖/制冷度日与建筑能耗有显著线性关系,被认为是最简单可靠的衡量能源需求的指标,但其适用性还缺乏全面的评估。通过模拟1961—2009年天津市办公、商场以及不同节能水平的居住建筑能耗,分析了能耗与采暖/制冷度日的关系,确定其反映能耗变化的适用性。结果表明:采暖期办公及商场建筑的热负荷与采暖度日的相关性达到极显著水平(P<0.01),决定系数(R2)分别为0.99和0.97;制冷期冷负荷与制冷度日的关系尽管也达到极显著水平,但决定系数仅分别为0.64和0.55;不同节能水平居住建筑热负荷与采暖度日极显著相关,决定系数均在0.99以上。研究认为:采暖度日可以反映办公、商场及居住建筑的热负荷特征,用于分析气候变化对能耗的影响是可行的;但制冷度日不能完全反映办公及商场建筑冷负荷的变化,仅可分别解释冷负荷变化的64%和55%,单纯用制冷度日研究能耗变化是不够全面的。通过分析能耗与气候要素的关系发现,冬季采暖期能耗主要受气温的影响,而夏季制冷能耗受气温和湿度的共同影响。

Heating and cooling degree-days have been considered to be the simplest and most reliable measures of building energy demands, but their applicability lacks comprehensive assessment. Hence, we simulated the energy consumption of different types of buildings （i.e. office buildings, department stores, and residential buildings with different energy saving levels） in Tianjin from 1961 to 2009 and analyzed its relationships with heating and cooling degree-days. The results show that the relationships between heat loads of office buildings or department stores and heating degree-days in winter reached a high significant level （P 〈 0.01） with a large determination coefficient （R2） of 0.99 and 0.97, respectively. However, during the hot summer period the determination coefficients （R 2） for office buildings and department stores were only 0.64 and 0.55 respectively, although the cooling loads were both significantly correlated with cooling degree-days （P 〈 0.01）. The heat loads of residential buildings with different energy saving levels were all closely correlated with heating degree-days and their determination coefficients were above 0.99. These results suggest that heating degree-days is able to reflect the characteristics of the heat loads of office buildings, department stores and residential buildings and thus can be used to study the impact of climate change on building energy consumption. By contrast, cooling degree-days is unable to entirely reflect the changes of the cooling loads of office buildings and department stores because the cooling degree-days can only explain 64% and 55% of their cooling loads, respectively. It was found from the analysis on relationships between building energy consumption and its relevant climatic factors that the energy consumption in the heating period was dominantly affected by temperature while in the hot summer period it was jointly affected by both temperature and humidity.