Abstract The integration of an array of two evacuated-tube solar collectors with a latent thermal energy storage system has been accomplished, in order to study the heat transfer characteristics during solar-driven melting. A shell-and-tube heat exchanger is employed for energy storage purposes, using 30 kg of paraffin RT70HC in the shell side. A tube bundle uniformly distributed accommodates 12 tube passes, allowing a total mass flow of 100–1000 kg/h of water for inducing turbulent-flow in the tube side. A Coriolis flowmeter is employed for measuring the mass flow through the tubes, and PT100 temperature sensors are used for measuring the inlet and exit temperature of the heat transfer fluid. Outside wall temperature is measured in different cross-sections of the tubes using T-type thermocouples, which capture the buoyancy plume of the PCM induced over the tubes during phase change. Vertical and horizontal temperature probe arrays in the shell characterize the thermal stratification that occurs during melting. Liquid fraction and energy storage during three different scenarios of solar irradiance are computed. The relation between the primary energy source and the heat transfer dynamics of the LTES are described, considering the constraints in terms of maximum PCM operating temperature and achievable liquid fraction.

中文翻译：

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壳管式热能存储器中太阳能驱动的熔化动力学：实验分析

摘要 为了研究太阳能驱动熔化过程中的传热特性，已经完成了两个真空管太阳能集热器阵列与潜热储能系统的集成。壳管式换热器用于储能目的，在壳侧使用 30 kg 石蜡 RT70HC。均匀分布的管束可容纳 12 个管程，允许总质量流量为 100-1000 kg/h 的水在管侧引起湍流。科里奥利流量计用于测量通过管道的质量流量，PT100 温度传感器用于测量传热流体的入口和出口温度。使用 T 型热电偶在管子的不同横截面测量外壁温度，它捕获了相变期间在管上引起的 PCM 的浮力羽流。壳中的垂直和水平温度探头阵列表征熔化过程中发生的热分层。计算了三种不同太阳辐照度情况下的液体分数和能量存储。考虑到最大 PCM 工作温度和可达到的液体分数方面的限制，描述了主要能源与 LTES 的传热动力学之间的关系。