摘要
提出一种蓄能型内插热管式太阳能集热器,在太阳能真空管和振荡热管蒸发段之间充灌相变材料,提高集热器的瞬时集热效率.利用Gambit软件建立内插热管式太阳能集热器的三维模型,基于FLUENT软件的凝固/熔化模型,以癸酸(CA)为相变材料进行模拟研究,采用Boussinesq近似法对比分析了考虑浮升力前后的真空管内温度场分布、液化率、不同测点的温度曲线的变化,探究了浮升力对集热器内蓄热/释热过程换热规律的影响.结果表明,相变材料熔化过程中浮升力起着至关重要的作用,使得真空管内顶部的升温速度快于底部.而凝固过程中浮升力的影响可以忽略不计.蓄热过程中集热器内相变材料在轴向上的传热方式,固态显热和相变蓄热阶段以导热为主,液态显热蓄热时以对流传热为主,而在径向上始终以导热为主.
In this study,a kind of energy storage type solar collector with inserted heat pipe is proposed,and the phase change material(PCM)is filled between the solar vacuum tube and the evaporation section of the oscillating heat pipe to improve the instantaneous collecting efficiency of the collector.In order to grasp the characteristics of phase change heat storage/release heat process in the collector,a three-dimensional model of a solar collector with inserted heat pipe is established by using Gambit software.Based on the solidification&melting model in FLUENT,the melting process of capric acid(CA)which is used as PCM is numerically simulated.The comparison and analysis of the vacuum tube considering natural convection are made by using Boussinesq approximation.Temperature distribution,liquefaction rate,and temperature change curves at different measurement point to explore the effect of buoyancy in the vacuum tube on the heat transfer flow mechanism during phase change energy storage.The results show that natural convection plays a vital role in the melting process of PCM,and that the temperature rises faster at the top of the vacuum tube than that at the bottom.The effect of buoyancy during the solidification process can be ignored.In the vacuum tube placed vertically,the heat transfer mode of the heat storage process in the axial direction,is mainly heat conduction at the solid sensible heat and the phase change heat storage stage,and at the liquid sensible heat storage stage is mainly convective heat transfer.In the radial direction,heat conduction is always the main factor.
作者
夏曼
王晓宇
吴薇
黄金燕
秦芷萱
杨晨
廖扬颡
Xia Man;Wang Xiaoyu;Wu Wei;Huang Jinyan;Qin Zhixuan;Yang Chen;Liao Yangsang(School of Energy and Mechanical Engineering,Nanjing Normal University,Nanjing 210023,China;Engineering Laboratory of Energy System Conversion and Emission Reduction of Jiangsu Province,Nanjing Normal University,Nanjing 210023,China)
出处
《南京师范大学学报（工程技术版）》
CAS
2020年第3期1-8,共8页
Journal of Nanjing Normal University(Engineering and Technology Edition)
基金
江苏省自然科学基金面上研究项目(BK20151549)
江苏省太阳能技术重点实验室开放课题(KLSST201903).
关键词
内插热管式太阳能集热器
相变储能
癸酸
浮升力
数值模拟
solar collector with inserted heat pipe
phase change energy storage
capric acid
buoyancy
numerical simulation
