【作者】 王敏；

【导师】 龙恩深； 赵力；

【作者基本信息】 四川大学 ， 建筑与土木工程（专业学位）， 2021， 硕士

【摘要】 我国夏热冬冷地区在冬季有较长的寒冷时期,但不属于集中供暖区域。随着经济快速发展及生活水平提高,供暖需求越来越大,但实际建筑多采用分散供暖设备的间歇用能模式。另外,为响应国家绿色发展战略,建筑节能的重要性逐渐凸显,建筑节能设计标准要求不断提高。外保温聚苯板材料上世纪八十年代从欧洲引入中国,节能效果在寒冷地区得到公认。随着建筑外保温在夏热冬冷地区广泛推广应用,保温墙体开裂、鼓泡,瓷砖脱落及火灾事故时有发生。建筑节能领域呼唤新的保温材料替代品。近期一种被宣称具有保温隔热效果的涂料出现在大众视野,且有权威机构出具报告证实其在建筑外墙涂刷0.5mm厚涂层的保温效果与30mm厚度聚苯保温板相当,突破了众多相关领域专家和大众对于墙体保温材料的传统认知。但因涂刷成型太薄而无法通过基于温差的热阻检测获得热阻数据来与保温板进行对比,其推广应用存在较大争议。针对这一热点问题,本文开展了以下工作:首先,针对外保温和外涂料两种保温建筑的室内热环境变化,构建两座基本相同的模型建筑,设置加热系统和温度数据采集系统搭建对比实验平台,以连续供暖模式为对照,设计开12小时关12小时、开4小时关4小时、开2小时关2小时三组不同间歇时长的对比实验,进行外保温板建筑和外涂料建筑在不同间歇供暖模式下室内空气、内壁面和外壁面温度变化的探索实验研究。其次,通过系统的对比实验研究,从内空内壁温变规律,供暖期和停暖期的不同角度分析发现:(1)在连续供暖模式,两座模型建筑对于内空气温度,供暖前6个小时外涂料建筑约高出1℃,供暖8小时后外保温建筑约高出2℃,供暖16小时后基本都达到各自稳定状态。内壁面温度变化规律与内空气温度变化类似,供暖前9个小时外涂料建筑约高出2℃,供暖10小时后外保温建筑约高出3℃,供暖16小时后基本达到稳定。两模型建筑的内空气和内壁的均温相差始终不到10%,远未达到60%的预期。(2)对于开12小时关12小时、开4小时关4小时和开2小时关2小时间歇供暖模式,分别在供暖期和停暖期进行了对比分析。在第一个供暖期,两模型建筑的室内空气温度变化与连续供暖相应时段内的规律相同,但达不到稳定。12-12模式中的室内空气温度在供暖前6个小时外涂料建筑约高出1℃,供暖8小时后外保温建筑约高出2℃,而4-4和2-2模式因供暖时长不足6小时而始终是外涂料建筑更高,两模型建筑之间的差异率仍然不到10%。内壁温度的变化规律与内空气温度类似,不同的是外涂料建筑更高的时段是供暖前9小时。在第一个停暖期,始终是外保温建筑的室内空气温度更高,两模型建筑之间的差异比在供暖期更大,外保温建筑高出20%,差异率随着间歇供暖时长缩短而减小,内壁面温度的变化类似,但整体温度要更低。随着间歇供暖持续循环进行,两模型建筑的温度变化都与第一个周期相似,但大小关系存在差异。然后,本文重点从室内空气均温升、内壁均温升、外壁均温升三个方面,通过在不同间歇供暖模式下的纵向对比、外保温和外涂料建筑的横向对比分析差异,对两模型建筑室内热环境进行了分析。间歇时长越小,供暖起点均温升和停暖起点均温升的递增阶梯都越高。基于此,对两模型建筑24小时内的平均内空气均温升、平均内壁均温升和平均外壁均温升三个温度参数以及各自的峰点值和谷点值进行了对比分析。在供暖期,两模型建筑的平均内空气均温升和平均内壁均温升分别在15～25℃和10～20℃范围内随间歇时长缩短而减小,差异率都不超过4%。在停暖期,两模型建筑的平均内空气均温升在0～10℃范围内随间歇时长缩短而增加,差异很大,超过20%;平均内壁均温升在10～20℃范围内随间歇时长缩短而增加,而差异在0-25%范围内减小。随着间歇时长的减小,两模型建筑内空气均温升和内壁均温升的峰点值减小而谷点值增加,峰谷差距都超过15℃,而外壁均温升的峰值未超过8℃,最低峰谷温差不超过1℃。基于以上现象,从建筑围护结构传热和蓄热的角度进行了理论分析,得出在间歇供暖模式下,间歇时长越短,外保温改善室内热环境的优势越难以体现,在初期的几个间歇循环周期中,外保温也不会体现出改善室内热环境的优势。最后,考虑室内空气温度以及内壁温度复合作用对建筑室内热环境的影响,本文利用累计温升差异百分比E_i对两模型建筑综合室内热环境进行评价分析。发现对于连续供暖模式,外保温建筑的室内热环境优于外涂料建筑的转折时间为18.95小时;各间歇供暖模式的整体转折时间分别是12-12模式14.95小时,4-4模式7.77小时、2-2模式11.41小时。结果表明,在夏热冬冷地区的绝大部分间歇供暖模式下,外保温是否能发挥改善室内热环境或节能的优势需要根据间歇时长和间歇供暖持续时长来综合判断。综上所述,本对比实验研究对不同间歇供暖模式下外保温和外涂料建筑的室内热环境变化进行了深入探讨,丰富了夏热冬冷地区对于间歇供暖建筑室内热环境的实验研究数据。研究结果可为该地区科学开展建筑节能有着重要的学术意义和工程参考价值。更多还原

【Abstract】 The hot summer and cold winter areas in China have a long cold period in winter,but they are not central heating areas.With the rapid development of economy and the improvement of living standard,the demand for heating is increasing,but the intermittent energy consumption mode of distributed heating equipment is mostly adopted.On the other hand,in response to the national green development strategy,the importance of building energy conservation is gradually highlighted,and the requirements of architectural energy-saving design standards are constantly improved.The external insulation was introduced from Europe to China in the 1980s,and the energy saving effect was recognized in cold areas.With the widespread application in hot summer and cold winter areas and hot and warm areas,the external insulation cracking,blistering,tile falling off and fire accidents occur.The field of building energy conservation calls for new insulation material substitutes.Recently,a coating with the effect of heat preservation and heat insulation has appeared in the public view.The report issued by authoritative organizations confirms that the insulation effect of 0.5mm thick coating applied on the external wall of the building is equivalent to that of 30mm thick polyphenylene insulation board,which breaks through the traditional cognition of many experts and the public in many related fields.However,it is controversial to use thermal resistance data to compare with thermal insulation board by thermal resistance detection based on temperature difference.In view of this hot issue,the following work is carried out in this paper.Firstly,according to the indoor thermal environment changes of external thermal insulation materials and external coating materials,two model buildings were constructed,and the heating system and temperature data acquisition system were set up to build a comparative experimental platform.Taking the continuous heating mode as the control,three groups of comparative experiments with different intermittent time were designed,including 12 hours on and 12 hours off,4 hours on and 4 hours off,2hours on and 2 hours off.The experimental study on the temperature changes of indoor air,inner wall and outer wall under different intermittent heating modes of insulation board building and exterior coating building was carried out.Secondly,through the systematic comparative experimental study,from the different angles of the inner wall temperature change law,heating period and stop heating period,it is found that:(1)In the continuous heating mode,for the internal air temperature,the external coating building is about 1℃higher than that in the first6 hours of heating,and the external insulation building is about 2℃higher than that in the first 8 hours of heating,and it is basically stable after 16 hours of heating.The temperature change of the inner wall is similar to that of the inner air.The temperature of the outer coating building is about 2℃higher than that of the inner air 9 hours before heating,and 3℃higher than that of the outer insulation building 10 hours after heating,which is basically stable after 16 hours of heating.The average temperature difference between the inner air and the inner wall of the two model buildings is less than 10%,which is far from the expectation of 60%.(2)The intermittent heating modes of 12 hours on and 12 hours off,4 hours on and 4 hours off,2 hours on and 2 hours off are compared and analyzed in heating period and stop heating period respectively.In the first heating period,the variation of indoor air temperature in the two model buildings is the same as that in the corresponding period of continuous heating,but it is not stable.The indoor air temperature of 12-12 mode is about 1℃higher than that of exterior coating building 6 hours before heating,and2℃higher than that of exterior insulation building 8 hours after heating.However,the difference rate between 4-4 and 2-2 mode is still less than 10%because the heating time is less than 6 hours.The change rule of the inner wall temperature is similar to that of the inner air temperature,but the higher period of the outer coating building is9 hours before heating.The difference between the two model buildings is more than20%higher than that in the heating period.The difference rate decreases with the shortening of intermittent heating time.The change of inner wall temperature is similar,but the overall temperature is lower.With the continuous cycle of intermittent heating,the temperature changes of the two model buildings are similar to the first cycle,but the size relationship is different.Then,the indoor thermal environment of the two models is analyzed from the three directions of the average temperature rise of indoor air,the average temperature rise of inner wall and the average temperature rise of outer wall through the longitudinal comparison under different intermittent heating modes and the transverse comparison with the external insulation and coating buildings.The smaller the interval time,the higher the step of average temperature rise at the starting point of heating and the step of average temperature rise at the starting point of stopping heating.Based on this,the average internal air temperature rise,average internal wall temperature rise and average external wall temperature rise within 24 hours,as well as the peak and valley values of each temperature parameter were compared and analyzed.During the heating period,the average internal air temperature rise and the average internal wall temperature rise of the two model buildings decrease with the shortening of the intermittent time in the range of 15～25℃and 10～20℃,respectively,and the difference rate is not more than 4%.During the cooling off period,the average air temperature rise of the two model buildings increased with the shortening of the interval time in the range of 0-10℃,with a great difference of more than 20%;the average inner wall temperature rise increased with the shortening of the interval time in the range of 10-20℃,with a decrease of 0-25%.With the decrease of the interval time,the peak value of the average air temperature rise and the average inner wall temperature rise in the two model buildings decreases,while the valley value increases.The difference between the peak and valley is more than 15℃,while the peak value of the average outer wall temperature rise is less than 8℃,and the lowest peak valley temperature difference is less than 1℃.Based on the above phenomenon,the theoretical analysis is carried out from the perspective of heat transfer and heat storage of building envelope.It is considered that in the intermittent heating mode,the shorter the intermittent time is,the more difficult it is for the external insulation to improve the indoor thermal environment.In the initial several intermittent cycles,the external insulation will not reflect the advantages of improving the indoor thermal environment.Finally,considering the combined effect of indoor air temperature and inner wall temperature on the indoor thermal environment of buildings,the evaluation method of comprehensive indoor thermal environment of two model buildings is established by using the accumulated temperature difference percentage E_i.It is found that for continuous heating mode,the indoor thermal environment of external insulation building is better than that of external coating building,and the turning time is 18.95hours;the overall turning time of each intermittent heating mode is 14.95 hours for 12-12 mode,7.77 hours for 4-4 mode and 11.41 hours for 2-2 mode respectively.The results show that in most of the intermittent heating modes in hot summer and cold winter areas,whether the external insulation can improve the indoor thermal environment or save energy needs to be comprehensively judged according to the intermittent duration and intermittent heating duration.To sum up,this comparative experimental study deeply discusses the indoor thermal environment changes of exterior insulation and exterior coating buildings under different intermittent heating modes,enriches the experimental research data of indoor thermal environment of intermittent heating buildings in hot summer and cold winter areas.The research results have important academic significance and engineering reference value for the scientific development of building energy conservation in this area.更多还原