夏热冬冷地区绿化屋顶节能与生态效益研究

【目的】研究夏热冬冷地区绿化屋顶的节能效益,分析包括固碳释氧、空气净化、水源涵养和节能减排4个方面的生态效益。【方法】以无锡地区有无绿化的屋顶为研究对象,对比绿化屋顶的保温隔热及节电效果,并进行屋顶绿化生态效益的量化分析。【结果】在冬季,绿化屋顶内、外表面平均温度比非绿化屋顶分别高2.5 ℃和5.5 ℃,通过屋顶的热流相对减少36.4%,绿化房间空调日平均节电量为0.90(kW·h); 在夏季,绿化屋顶内、外表面平均温度比非绿化屋顶分别低3.1 ℃、5.6 ℃,通过屋顶的热流相对减少48.6%,日平均空调节电量为4.23(kW·h)。计算可得,绿化屋顶每年可节约空调用电量15.39(kW·h)/m²; 佛甲草屋顶绿化可创造的固碳释氧效益为1.887元/(m²·a),净化空气效益为2.45×10^-2元/(m²·a),涵养水源效益为0.957元/(m²·a),节能效益可达到12.875元/(m²·a),减排效益达9.613元/(m²·a),综合生态效益是25.357元/(m²·a),动态投资回收期为7 a。【结论】屋顶绿化在冬季可提高屋顶内外表面温度,在夏季降低屋顶内外表面温度,减少通过屋面的热流,达到保温隔热和降低空调能耗的节能效果。屋顶绿化的生态效益显著,投资回收期短,应予以政策鼓励和支持。

Experimental study on thermal insulation performance of green roof in hot summer and cold winter area

【Objective】This paper illustrates the energy-saving benefit of green roof in hot summer and cold winter area and the ecological benefits including carbon oxygen release, air purification and water conservation and energy conservation.【Method】The thermal insulation and energy-saving effect of green roof is analyzed through the contrast experiment with and without green roof, and four aspects of green roof’s ecological benefit are quantitatively analyzed. 【Result】It shows that in winter the average inside and outside surface temperature of the green roof is higher than that of the common roof by 2.5 ℃ and 5.5 ℃, the heat flux through the roof decreases by 36.4% and the average daily electricity saving quantity is 0.90(kW·h)for air conditioner. In summer, both the inside and outside surface temperature of green roof is lower than that of the common roofs by 3.1 ℃ and 5.6 ℃, respectively, the heat flux through the roof is reduced by 48.6%, the average daily electricity saving quantity is 4.23(kW·h). It indicates that the electricity saving quantity is 15.39(kW·h)/m² every year for the air conditioner. Per unit area of green roof can create the benefit of carbon oxygen release a year is 1.887 Yuan, air purification efficiency 2.45×10^-2 Yuan/(m²·a), water conservation benefit is 0.957 Yuan/(m²·a), energy-saving efficiency is 12.875 Yuan/(m²·a), emissions reduction benefit is 9.613 Yuan/(m²·a), and quantitative ecological benefits is 25.357 Yuan/(m²·a), with the dynamic payback period of 7 years. 【Conclusion】Roof greening can improve both inside and outside surface temperature of the roof in winter, and reduce the roof temperature, as well as the heat flow through the roof, reaching thermal insulation and reducing energy consumption of air conditioning energy saving effect. The ecological benefit of roof garden is remarkable, with short payback period, and it must be paid to encourage and support by the policy.