夏热冬冷地区建筑热桥传热分析

发布时间：2018-04-19 17:20

本文选题：加气混凝土砌块 + 热桥　；参考：《武汉理工大学》2015年硕士论文

【摘要】：夏热冬冷地区,常见的保温类型有外保温、内保温和自保温三种。热桥形式多种多样,且热桥的存在,增加了通过围护结构的传热量。而准确计算通过热桥部位的传热量,是定量评价建筑能耗水平的基础。夏热冬冷地区对热桥的研究多局限于一维传热法,即用面积加权法考虑热桥的影响。但随着节能工作的推进,越来越多的高性能高温隔热材料得到应用,热桥的二维、三维影响愈加凸显。因此,应该重视热桥传热的研究。热桥种类繁多而且与各地气候条件密切相关。本文结合武汉地区冬季的气候条件,选取有代表性的外墙热桥类型(中柱热桥、梁热桥)进行研究,并分为3种保温形式:外保温、自保温和自保温。将墙体总热流量、热桥附加热流量、热桥附加热流量占总热流量的比例、热桥影响区域、热桥影响区域内热损程度这几个关键指标作为衡量热桥传热的标准。用ANSYS分析不同模型的传热情况。根据温度场、热流密度场的特点,得出热桥影响区域,对热流密度进行积分求得热桥附加热流量和热桥影响区域内的热损程度。本文进行了两方面的比较:一是定量地比较了同种热桥在外保温、内保温和自保温三种形式下传热的区别。结果表明:对于中柱热桥,外保温的效果最好,使用了高性能B05加气混凝土砌块的自保温次之,内保温最差,但热桥影响区域最小。而对于梁热桥,采用外保温可以有效阻断热桥的产生。二是同种热桥形式同种保温形式下参数变化对传热桥热的影响,选取了不同保温层厚度、不同保温材料、不同柱宽、柱高(或梁高)以及不同砌块类型进行模拟分析。结果表明:对热桥传热影响最大的是保温层的厚度改变以及保温材料的使用。其中,外保温体系对减小热桥影响作用显著。内保温体系存在的主要问题是由于保温的不连续,热桥附加热流量过大,这一缺陷可以通过保温层向内侧延伸得到改善。自保温体系存在的问题是由于热桥影响区域内热损程度过大,如果对保温层两边进行延伸200mm,即可有效阻断热桥。通过以上研究对节能设计提供理论基础,根据热桥影响区域的大小以及热损程度对构造加以改进。
[Abstract]:In hot summer and cold winter area, the common types of heat preservation are external insulation, internal insulation and self-insulation.The thermal bridge has a variety of forms and the existence of the thermal bridge increases the heat transfer through the enclosure structure.The accurate calculation of heat transfer through the heat bridge is the basis for quantitative evaluation of building energy consumption.The study of thermal bridge in hot summer and cold winter area is limited to one dimensional heat transfer method, that is, the area weighting method is used to consider the influence of thermal bridge.However, with the development of energy conservation, more and more high performance high temperature insulation materials have been applied, and the effects of two and three dimensional heat bridges have become more and more prominent.Therefore, attention should be paid to the study of heat transfer over heat bridges.There are many kinds of hot bridges and they are closely related to local climatic conditions.According to the climatic conditions in winter in Wuhan area, this paper selects representative types of thermal bridges for exterior wall (medium column hot bridge, beam heat bridge), and divides them into three types of thermal insulation: external insulation, self-preservation and self-insulation.The total heat flux of the wall, the additional heat flux of the heat bridge, the proportion of the additional heat flux of the heat bridge to the total heat flux, the influence area of the heat bridge and the heat loss degree of the heat bridge are taken as the criteria to measure the heat transfer of the heat bridge.The heat transfer of different models was analyzed by ANSYS.According to the characteristics of the temperature field and the heat flux field, the influence area of the heat bridge is obtained. The additional heat flux of the heat bridge and the heat loss degree in the area affected by the heat bridge are obtained by integrating the heat flux.In this paper, two comparisons are made: first, the difference of heat transfer between the same heat bridge external heat preservation, internal heat preservation and self heat preservation is quantitatively compared.The results show that the effect of external thermal insulation is the best for the middle column hot bridge. The self-insulation of the high performance B05 aerated concrete block is the second, the internal insulation is the worst, but the influence area of the thermal bridge is the least.For the beam heat bridge, the use of external heat preservation can effectively block the generation of the thermal bridge.The second is the influence of the change of parameters on the heat transfer bridge under the same heat bridge form. Different insulation layer thickness, different insulation material, different column width, column height (or beam height) and different block types are selected to simulate the heat transfer bridge heat transfer.The results show that the thickness change of insulation layer and the use of thermal insulation material have the greatest influence on the heat transfer of the heat bridge.Among them, the external thermal insulation system has a significant effect on reducing the thermal bridge.The main problem of the internal thermal insulation system is that the heat flux of the heat bridge is too large because of the discontinuity of the heat preservation. This defect can be improved by extending the insulation layer to the inner side.The problem of the self-insulation system is that the heat loss degree in the area affected by the heat bridge is too large. If the thermal insulation layer is extended to both sides 200mm, the thermal bridge can be effectively blocked.The above research provides the theoretical basis for energy saving design and improves the structure according to the size of the heat bridge affected area and the heat loss degree.
【学位授予单位】：武汉理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU111.41

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