Mousavi S M, Sheikholeslami M
Department of Mechanical Engineering, Babol Noshirvani University of Technology, Babol, Islamic Republic of Iran.
Renewable Energy Systems and Nanofluid Applications in Heat Transfer Laboratory, Babol Noshirvani University of Technology, Babol, Islamic Republic of Iran.
Sci Rep. 2024 Apr 4;14(1):7939. doi: 10.1038/s41598-024-58276-4.
This study discusses an evacuated tube collector-type solar water heater (ETCSWH) using a phase change material (PCM) chamber with fins, nanofluid, and nano-enhanced phase change material (NEPCM). First, the charging phenomena in a horizontal triplex tube heat exchanger (TTHX) equipped with fins, natural convection, and an ETCSWH system without PCM is simulated to validate the solution. The impact of adding fins and nanoparticles with a volume fraction of 3% of AlO and Cu to paraffin wax and water-based fluid, respectively, on the unit's efficiency has been examined. The proposed system for the PCM melting process, heat storage, fluid flow behavior in the system, and velocity distribution and temperature contour in the storage tank and three parts of the absorber tube have been evaluated using ANSYS FLUENT software in a three-dimensional and transient simulation. The results show that Case 8 has improved by 39.7% compared to Case 1 and Case 4 by 5.2% compared to Case 1 within 4 h of the melting process. Also, Case 8 with a 43% and 6.4% shorter melting time than Cases 1 and 5 has the best performance and the greatest heat transfer rate. The productivity of the ETCSWH system is considerably enhanced by the use of fins, NEPCM, and nanofluid.
本研究讨论了一种带有翅片、纳米流体和纳米增强相变材料（NEPCM）的相变材料（PCM）腔的真空管集热器式太阳能热水器（ETCSWH）。首先，对配备翅片、自然对流且无PCM的ETCSWH系统的卧式三管热交换器（TTHX）中的充电现象进行模拟，以验证解决方案。分别研究了向石蜡和水基流体中添加体积分数为3%的AlO和Cu纳米颗粒对装置效率的影响。使用ANSYS FLUENT软件在三维瞬态模拟中对所提出的PCM熔化过程、蓄热、系统中的流体流动行为以及储水箱和吸收管三个部分的速度分布和温度等值线进行了评估。结果表明，在熔化过程的4小时内，案例8比案例1提高了39.7%，案例4比案例1提高了5.2%。此外，案例8的熔化时间比案例1和案例5分别短43%和6.4%，具有最佳性能和最大传热速率。使用翅片、NEPCM和纳米流体可显著提高ETCSWH系统的生产率。
