摘要
夜间辐射冷却相变墙体能够有效地利用自然冷源降低建筑空调能耗,减少碳排放,是实现建筑节能的有效形式之一。分离式重力热管是该墙体系统实现热量输运的重要组成部分,其传热特性直接影响墙体系统的热工特性。本文利用VOF方法建立分离式重力热管二维数值模型,模拟该热管在墙体热边界下的热特性与流动特性。结果表明,在蒸发端28℃、冷凝端22℃时,热管在平衡状态时工质整体温度约为26.4℃,换热量可达到524 W/m^(2),工质流速约为0.2 m/s。进一步模拟了不同蒸发/冷凝边界温差对热管换热量的影响,温差越大该热管换热效果越好。
The nocturnal radiative cooling PCM(Phase Change Material) wall can effectively use natural cooling sources to reduce the energy consumption of buildings for cooling as well as carbon emission,serving as one of the effective means for building energy efficiency.Separated gravity heat pipe is an important part of the heat transport of the wall system,and its heat transfer characteristics directly affect the thermal performance of nocturnal radiative cooling PCM walls.In this paper,a two-dimensional numerical model of the separated gravity heat pipe was built using the VOF method.The thermal and flow characteristics of the heat pipe under the thermal boundary of the wall system were simulated and analyzed.Results show that when the boundary of 28 ℃ at the evaporation end and 22 ℃ at the condensation end,the overall temperature of the working fluid inside the heat pipe in the equilibrium state is about 26.4 ℃.The heat exchange can reach 524 W/m^(2) and the flow speed of the working fluid is about 0.2 m/s.The influence of different evaporation/condensation temperature differences on the heat transfer effect was further studied.The larger the temperature difference,the better the heat transfer effect of the heat pipe.
作者
徐大卫
严天
徐新华
于靖华
汤小亮
於仲义
XU Dawei;YAN Tian;XU Xinhua;YU Jinghua;TANG Xiaoliang;YU Zhongyi(School of Environmental Science&Engineering,Huazhong University of Science and Technology,Wuhan 430074,China;CITIC General Institute of Architectural Design and Research Co.,Ltd.,Wuhan 430014,China)
出处
《建筑科学》
CSCD
北大核心
2024年第6期193-199,共7页
Building Science
基金
国家自然科学基金资助项目“辐射内嵌并联分离式重力热管的传热机理及性能优化研究”(52208109)
“基于自然能的被动再生干燥床与双层调湿结构墙体房间耦合的湿调节机制研究”(52378099)
中信集团重大科研项目(双碳专项)“碳达峰与碳中和背景下夏热冬冷地区超低能耗建筑关键技术体系研究”(2022ZXKYD30100)。
关键词
夜间辐射冷却相变墙体
分离式重力热管
建筑节能
传热特性
VOF模型
nocturnal radiative cooling phase change material wall
separated gravity heat pipe
building energy efficiency
thermal characteristic
VOF model
