摘要
相变储冷凝胶因其良好的稳定性在冷链运输中具有良好的应用前景,但其高黏度、低流动性的特点抑制了相变过程中的自然对流,影响了储冷器的传热性能,从而降低了冷能利用效率。本工作建立了二维管翅式储冷器的CFD模型,基于FLUENT软件的熔化/凝固模型,研究了相变储冷凝胶的流动性对储冷器传热性能的影响;对比了不同结构储冷器充冷效率,定义了无量纲数e表示结构充冷效率,并探究了不同储冷器结构对充冷过程的影响。结果表明,在-5℃冷源充冷下,有自然对流的储冷凝胶相较于无自然对流的储冷凝胶充冷时间缩短12%;在重力场的作用下,不同区域不同时间的储冷凝胶流动性不同,在凝固过程前期以及在储冷器上方的储冷凝胶流速较快且流场范围较大、传热更快;双管结构表现出更高的充冷效率。本研究有助于推动相变储冷器在冷链运输中的应用,并为优化相变储冷器结构提供理论依据。
Phase change cold storage gels have considerable potential for applications in cold chain transportation owing to their good stability.However,their high viscosity and low fluidity inhibit the natural convection during the phase change process,which affect the heat transfer performance of cold storage equipment,thereby reducing the efficiency of cold energy utilization.Herein,a two-dimensional CFD model for tube-fin-type cold storage equipment was established and the influence of the fluidity of phase change cold storage gel on its heat transfer performance was investigated based on the melting-solidification model of FLUENT software.The study compares the cold charging efficiencies of various structural cold storage equipment,introduces the dimensionless number e to represent structural cold charging efficiency,and explores the effect of various structures of cold storage equipment on the cold charging process.Results reveal that the cooling time for cold storage gel with natural convection is 12% shorter than that without natural convection at-5 ℃.Furthermore,under the effectof gravity field,the mobility of cold storage gel varies across different areas and times.Notably,during the early stage of the solidification process and in the cold storage gel above the cold storage equipment,the flow rate of cold storage gel is faster and flow field range is larger,resulting in faster heat transfer.The double-tube structure exhibits a higher cooling efficiency.This study helps to advance the application of cold storage equipment in cold chain transportation and offers a theoretical basis for optimizing the structure of cold storage equipment.
作者
谭振炜
李沐
李传常
TAN Zhenwei;LI Mu;LI Chuanchang(School of Energy and Power Engineering,Changsha University of Science and Technology;State Key Laboratory of Disaster Prevention&Reduction for Power Grid,Changsha University of Science&Technology,Changsha 410114,Hunan,China)
出处
《储能科学与技术》
CAS
CSCD
北大核心
2023年第12期3740-3748,共9页
Energy Storage Science and Technology
基金
国家自然科学基金项目(52274252)
湖南省重点研发计划(2022GK2048,2023NK2032)
湖南省湖湘青年英才(2020RC3038)
长沙市杰出创新青年培养计划(kq1802007)。
关键词
冷链运输
相变储冷
自然对流
数值模拟
传热分析
cold chain transportation
phase change cold storage
natural convection
numerical simulation
heat transfer analysis
