Climate adaptive thermal characteristics of envelope of residential passive house in China

中国被动式住宅围护结构的气候适应性热特性研究

Passive house has been constructed in China on a large-scale over the past couple years for its great energy saving potential.However,research indicates that there is a significant discrepancy in energy performance for heating and cooling between passive houses in different climate zones.Therefore,this research develops a comparative analysis on the energy saving potential of passive houses with the conventional around China.A sensitivity analysis of thermal characteristics of building envelope(insulation of exterior walls and windows,and airtightness)on energy consumption is further carried out to improve the climate adaptability of passive house.Moreover,the variation of energy consumption under different heat gain intensity is also compared,to evaluate the effects of envelope thermal characteristics comprehensively.Results suggest that the decrease of exterior wall insulation leads to the greatest increase in energy consumption,especially in severe cold zone in China.However,the optimal insulation may change with the internal heat gain intensity,for instance,the decrease of insulation(from 0.4 to 1.0 W/(m^(2)·K))could reduce the energy consumption by 4.65 kW·h/(m^(2)·a)when the heat gain increases to 20 W/m^(2)for buildings in Hot Summer and Cold Winter zone in China.

被动房由于其高保温和高气密性特征,具有巨大的节能潜力。近年来,中国开展了大规模被动房建设。然而,调研显示被动房之间存在显著的能源性能差异,尤其是在不同气候区。因此,本研究基于建筑仿真模型对被动房能耗进行比较分析,以探究被动房在不同气候区的节能潜力。由于气候差异主要影响建筑物的供冷采暖负荷,本文以被动房屋供暖、通风和空调系统的能耗为研究对象,并与传统房屋能耗对比。为进一步提高被动房气候适应性,本文对建筑围护结构的热参数进行敏感性分析,定量探究了外墙和窗户保温以及气密性对不同气候区供冷采暖能耗。此外,还计算了不同内热源强度下供冷采暖能耗变化,综合分析围护结构热特性对建筑能耗的影响。结果表明,外墙保温减弱会导致能耗大幅增长,尤其是对于中国严寒地区被动房。然而,保温需求会随着内热源强度的变化而变化,例如对于夏热冬冷地区的被动房,当内热源密度增加到20 W/m^(2)时,最佳保温强度将从0.4 W/(m^(2)·K)(标准值)降低至1.0 W/(m^(2)·K),从而每年可节省4.65 kW·h/(m^(2)·a)供冷采暖能耗。