Heat transfer enhancement in medium temperature thermal energy storage system using a multitube heat transfer array
Heat transfer enhancement in medium temperature thermal energy storage system using a multitube heat transfer array
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DOI：
10.1016/j.renene.2009.03.010
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发表时间：
2010-01-01
期刊：
影响因子：
8.7
通讯作者：
Smyth, Mervyn
中科院分区：
文献类型：
--
作者：
Agyenim, Francis;Eames, Philip;Smyth, Mervyn
设计了一种实验储能系统，采用卧式管壳式热交换器，采用熔点为 117.7 摄氏度的中温相变材料 (PCM)。研究了两种实验配置，包括带有一根传热管的控制单元和带有四根传热管的多管单元。使用等温线图和温度时间曲线分析了系统的热特性。对沿壳管系统轴向、径向和角向三个方向的温度梯度进行了分析和比较。与控制系统中的传导传热相比，多管系统中的相变主要受对流传热的影响。对于控制系统和多管系统来说，相变过程中，PCM 中的温度梯度在径向方向上最大。在相变过程中，控制系统和多管系统轴向记录的温度梯度分别是径向温度的 2.5% 和 3.5%，这表明 PCM 中本质上是二维传热。通过在多管系统中形成多个对流单元而产生的自然对流显着改变了固液界面流体流动的形状，并表明需要对多管布置进行深入研究。 (C) 2009 Elsevier Ltd. 保留所有权利。
An experimental energy storage system has been designed using an horizontal shell and tube heat exchanger incorporating a medium temperature phase change material (PCM) with a melting point of 117.7 degrees C. Two experimental configurations consisting of a control unit with one heat transfer tube and a multitube unit with four heat transfer tubes were studied. The thermal characteristics in the systems have been analysed using isothermal contour plots and temperature time curves. Temperature gradients along the three directions of the shell and tube systems: axial, radial and angular directions have been analysed and compared. The phase change in the multitube system was dominated by the effect of convective heat transfer compared to conductive heat transfer in the control system. The temperature gradient in the PCM during phase change was greatest in the radial direction for both the control and multitube systems. The temperature gradients recorded in the axial direction for the control and multitube systems during the change of phase were respectively 2.5 and 3.5% that of the radial direction, indicating essentially a two-dimensional heat transfer in the PCM. The onset of natural convection through the formation of multiple convective cells in the multitube system significantly altered the shape of the solid liquid interface fluid flow and indicates the requirement for an in-depth study of multitube arrangements. (C) 2009 Elsevier Ltd. All rights reserved.