轻型木结构墙体稳态传热性能及其保温材料影响比较

轻型木结构墙体的热工性能对建筑节能至关重要,其稳态传热性能是节能效率评估指标之一。工程调研发现,轻型木结构墙体墙骨柱热传递过程易产生冷热桥,改善墙体保温构造并通过试验测试,对得到不同构造的墙体传热系数等指标进行分析研究,有利于设计人员优选墙体设计参数、研发墙体新型保温材料。试验采用标定热箱法与热流计法相结合的试验方法——控温箱-热流计法对改善保温措施的墙体进行试验,分析了12种墙体试件的热流密度、传热系数、热阻以及日传热量参数,并与理论计算结果进行比较验证,试验结果与理论计算结果吻合性较好。研究发现:气凝胶毡放置在墙骨柱位置能够有效降低平均传热系数3.8%~15.0%,随厚度增加可逐渐减弱或消除墙骨柱冷热桥效应;聚苯乙烯保温板可有效降低传热系数32.4%~35.1%,墙体蓄热能力较好;纳米纤维保温材料可有效降低传热系数5.9%~8.7%,提高墙体冷热面温差,平衡室内温度。选取的3种保温材料中,聚苯乙烯保温板相比气凝胶毡和纳米纤维保温材料,对墙体整体热工性能的提升更为显著。

Comparation of thermal insulation materials and steady state heat transfer performance of light-frame wood structures wall

The light-frame wood structure building has been widely developed in Chinese construction field because of its light weight,low cost,convenient materials,green environmental protection and short construction period.One of the key issues in the current development of light-frame wood structures is to effectively improve the thermal insulation performance of the wall,and also guarantee the living environment and build a green,environmentally friendly,lowenergy consumption buildings.The thermal performance of the light-frame wood wall is very important for achieving energy conservation,and its steady state heat transfer performance is one of the energy efficiency evaluation indicators.In this study,hot and cold bridges always exist in the heat transfer process of light-frame wood wall.By improving the wall thermal insulation structure for experimental tests,the heat transfer coefficients of different structural walls and other indicators were obtained.It is beneficial for designers to optimize wall design parameters,develop new wall insulation materials and continuously improve indoor thermal comfort.In this study,the heat flux,heat transfer coefficient,heat resistance and daily heat transfer of the 12 wall specimens were measured and analyzed by the temperature control box-heat flow meter.The reliability of the theoretical calculation was verified by the experimental data.As a result,it was confirmed that aerogel insulation felt could reduce the average heat transfer coefficient by 3.8% to 15.0% when it was set on the studs,the cold and hot bridge effect of the wall studs could be eliminated by increasing the wall thickness.The internal thermal insulation material could effectively reduce the heat transfer coefficient by 32.4% to 35.1% and the wall heat storage capacity was increased.The nano-beads insulation coating insulation material could reduce the heat transfer coefficient by 5.9% to 8.7%,which could increase the temperature difference between hot and cold sides of the wall and balance the indoor temperature.Compared with the aerogel insulation felt and nano-beads insulation coating insulation material,the internal thermal insulation material had the most significant impact on the thermal performance of the wall.The tested 12 walls were belonged to Grade It,and the heat transfer coefficients were all lower than 0.40 W/(m2·K).Among them,five types of walls were suitable for severe cold(A) areas,six types of walls were suitable for severe cold(B) areas,and nine types of walls were suitable for severe cold(C) areas.