摘要
墙体辐射得热量是影响围护结构传热性能的主要因素,基于下垫面反射特性研究代表性城市建筑墙体辐射得热尤为重要.选取哈尔滨、北京和兰州3个城市草地和砖地下垫面,以太阳直接辐射量和天空散射辐射量之和为对照组,探讨了下垫面反射特性对室外空气综合温度、不同城市辐射能、反射辐射能占总辐射能比重及对建筑墙体总辐射能的影响.结果表明:与对照组相比,下垫面反射会对室外空气综合温度和外墙体辐射得热量产生不同程度的影响,3个城市室外空气综合温度增大2.5℃以上的小时数均为4 h,增值范围为0.51～5.23℃;下垫面反射会加剧建筑墙体辐射得热,不论是草地还是砖地,不同下垫面反射辐射占总辐射能的比重由大到小依次为兰州>北京>哈尔滨;夏季砖地的反射辐射比草地分别多77.6 MJ/m2、84.2 MJ/m2和87.6 MJ/m2,冬季则分别为23.0 MJ/m2、30.8 MJ/m2和32.4 MJ/m2.对进一步改善建筑周边热环境及合理布局建筑室外下垫面提供理论基础.
Abstract
The radiation heat gain from walls is the main influencing factor in studying the heat transfer performance of enclosure structures,and it is particularly important to study the radiation heat gain from representative urban building walls based on the reflection characteristics of the underlying surface. The article selects three cities,Harbin,Beijing,and Lanzhou,and uses the sum of direct solar radiation and scattered sky radiation as the control group to explore the impact of the reflection characteristics of the underlying surface on the comprehensive outdoor air temperature,radiation energy in different cities,the proportion of reflected radiation energy to total radiation energy,and the impact on the total radiation energy of building walls. The results showed that compared with the control group,the reflection of the underlying surface had varying degrees of impact on the comprehensive outdoor air temperature and the radiation heat gain from the exterior wall. The hours when the comprehensive outdoor air temperature of the three cities increased by 2.5 ℃ or more were all 4 hours,with a value increase range of 0.51 ℃ to 5.23 ℃;The reflection of the underlying surface will intensify the radiation and heat gain of the building wall. Whether it is grassland or brick ground,the proportion of the reflected radiation of different underlying surfaces to the total radiation energy is in descending order:Lanzhou>Beijing>Harbin;In summer,the reflected radiation of brick ground is 77.6 MJ/m2,84.2 MJ/m2,and 87.6 MJ/m2 more than that of grassland,respectively;In winter,it is 23.0 MJ/m2,30.8 MJ/m2,and 32.4 MJ/m2 . This study provides a theoretical basis for further improving the thermal environment around buildings and rationalizing the layout of outdoor underlying surfaces.
基金项目
内蒙古自治区高等学校碳达峰碳中和研究专项(STZX202230)
内蒙古自治区自然科学基金(2022QN05014)
NETL
NSTL
万方数据