Sundaram Palanichamy, Sathishkumar Anbalagan, Liu Jie, Prabakaran Rajendran, Ganesh Kumar Poongavanam, Pragathi Pandian, Kim Sung Chul
Department of Mechanical Engineering, SRM Institute of Science and Technology, Tamil Nadu, Kattankulathur, Chennai, 603203, India.
School of Mechanical Engineering, Yeungnam University, 280 Daehak-Ro, Gyeongsan, Gyeongbuk, 712-749, Republic of Korea.
Environ Sci Pollut Res Int. 2024 Apr 12. doi: 10.1007/s11356-024-33251-8.
In building cooling, the demand for cooling surges during specific times, stressing air-conditioner operation, and additional cooling is often wasted during low-demand periods. Water-phase change material (W-PCM)-based thermal energy storage (TES) allows for load shifting and effective management of peak demand by storing cooling energy when the demand is low. This stored energy can be deployed during peak hours, decreasing energy usage and associated CO emissions. However, the use of W-PCMs was hindered by phase separation, slow energy transfer, and high supercooling degree (SCD). We synthesized coconut shell (CNS)-produced activated carbon (ACC) to use as a thermal enhancer in W-PCMs for the first time. First, ACC was synthesized from CNS via steam activation. Then, transmission electron microscopy was used to confirm the pore morphology of the CNS-ACC. The synthesis of the W-PCM with various weight percentages (0.1, 0.6, and 1.2) of CNS-ACC was accomplished in two steps. Zeta potential distribution analysis revealed that the W-PCM with CNS-ACC exhibited colloidal stability. Thermal conductivity (TC) and thermogram analyses revealed that a dose of 1.2 wt% CNS-ACC enhanced liquid and solid TC by 9% and 22%, respectively, despite a 6% and 8% decrease in specific heat and latent heat. More specifically, solidification assessment in a spherical enclosure revealed 100% suppression of SCD with 1.2 wt% CNS-ACC. As a result of this and the enhanced TC, the overall solidification process was accelerated, reducing the overall duration by 18.5%. Thus, the combination of CNS-derived ACC and W-PCM for TES in building cooling could reduce energy consumption and associated CO emissions.
在建筑制冷中，特定时段对制冷的需求激增，给空调运行带来压力，而在需求较低时期，额外的制冷量往往被浪费。基于水相变化材料（W-PCM）的热能储存（TES）可实现负荷转移，并通过在需求较低时储存冷能来有效管理峰值需求。这些储存的能量可在高峰时段使用，从而减少能源消耗及相关的二氧化碳排放。然而，W-PCM的使用受到相分离、能量传递缓慢和过冷度（SCD）高的阻碍。我们首次合成了由椰壳（CNS）制成的活性炭（ACC），用作W-PCM中的热增强剂。首先，通过蒸汽活化法由CNS合成ACC。然后，使用透射电子显微镜确认CNS-ACC的孔隙形态。分两步完成了含有不同重量百分比（0.1%、0.6%和1.2%）CNS-ACC的W-PCM的合成。zeta电位分布分析表明，含有CNS-ACC的W-PCM具有胶体稳定性。热导率（TC）和热成像分析表明，尽管比热容和潜热分别下降了6%和8%，但1.2 wt%的CNS-ACC剂量分别使液体和固体TC提高了9%和22%。更具体地说，在球形封闭空间中的凝固评估显示，1.2 wt%的CNS-ACC可100%抑制SCD。由于这一点以及增强的TC，整体凝固过程加速，总持续时间减少了18.5%。因此，将CNS衍生的ACC与W-PCM结合用于建筑制冷中的TES，可以降低能源消耗及相关的二氧化碳排放。
