Performance study of a thermochemical energy storage reactor embedded with a microchannel tube heat exchanger for water heating
Performance study of a thermochemical energy storage reactor embedded with a microchannel tube heat exchanger for water heating
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DOI：
10.1016/j.est.2023.110043
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发表时间：
2024-02
影响因子：
9.4
通讯作者：
Yong Zhang;Mingke Hu;Ziwei Chen;Yuehong Su;S. Riffat
中科院分区：
文献类型：
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作者：
Yong Zhang;Mingke Hu;Ziwei Chen;Yuehong Su;S. Riffat
热化学储能（TCES）为解决太阳能热生产与建筑物供暖需求之间的不匹配提供了一种有前途的解决方案。然而，现有的基于空气的开放式TCES系统在与中央水加热系统集成和控制供应温度方面面临实际挑战。为了克服这些局限性，一种新的水基TCES-HEX-HRU系统，提出了在这项研究中，它集成了水-空气微通道管换热器（HEX）和空气-空气热回收单元（HRU）。TCES-HEX-HRU系统的综合评估进行数值使用COMSOL模型，包括不同的TCES系统配置的比较评估。结果表明，TCES-HEX-HRU系统的整体热效率达到82.35%，比TCES-HEX系统提高了69个百分点。虽然比不带HEX和HRU的典型空气TCES系统略低15.44个百分点，但TCES-HEX-HRU系统在集中供暖系统中的应用中是一个有前途和可行的选择。数值计算结果表明，系统的热性能受气流和水流入口条件的影响。此外，增加TCES-HEX-HRU系统的HEX中的水通道的数量增强了热传递，但减少了TCES复合材料释放的热量，导致35个通道的最大总热效率为92.09%，30个通道的峰值出口水温为33.67 °C。然而，通道数量的进一步增加导致整体热效率和出水温度的下降。HEX中水通道宽度的变化对最高出水温度和整体热效率的影响较小，同时影响TCES复合材料的体积。
Thermochemical energy storage (TCES) provides a promising solution to addressing the mismatch between solar thermal production and heating demands in buildings. However, existing air-based open TCES systems face practical challenges in integrating with central water heating systems and controlling the supply temperature. To overcome these limitations, a novel water-based TCES-HEX-HRU system is proposed in this study, which integrates a water-to-air microchannel tube heat exchanger (HEX) and an air-to-air heat recovery unit (HRU). A comprehensive evaluation of the TCES-HEX-HRU system is conducted numerically using a COMSOL model, including a comparative assessment for different TCES system configurations. The results demonstrate that the TCES-HEX-HRU system achieves an overall thermal efficiency of 82.35 %, marking a substantial 69 percentage points improvement over the TCES-HEX system. Although slightly lower than the typical air-based TCES system without HEX and HRU by 15.44 percentage points, the TCES-HEX-HRU system can be a practically promising and viable choice for applications in central heating systems. Numerical investigations indicate that the thermal performance of the system is influenced by the inlet conditions of airflow and waterflow. Moreover, increasing the number of water channels in the HEX of the TCES-HEX-HRU system enhances heat transfer but reduces the amount of heat released by TCES composite materials, resulting in a maximum overall thermal efficiency of 92.09 % with 35 channels and a peak outlet water temperature of 33.67 °C at with 30 channels. However, further increases in the number of channels lead to a decline in overall thermal efficiency and outlet water temperature. Changes in the width of water channels in the HEX have a minor impact on the highest outlet water temperature and overall thermal efficiency, while affecting the volume of the TCES composite materials.