Performance analysis of a novel biomimetic bamboo-joint latent heat thermal energy storage system

With the ongoing progress of the "dual carbon" initiative, the development of efficient energy storage systems has emerged as a critical research focus. To improve the efficiency of phase-change energy storage systems, this study introduces a novel biomimetic bamboo-joint latent heat thermal energy storage system (BBJ-LHTES) inspired by the bamboo joint structure. A computational fluid dynamics (CFD)-based numerical model of the system was developed, and the phase change material (PCM) melting process was compared across four distinct scenarios. Subsequently, single-factor analyses and orthogonal experiments were performed to investigate the key parameters affecting the thermal performance of the system. The results indicated that the biomimetic bamboo-joint structure significantly enhanced the PCM melting rate, with the liquid fraction increased by approximately 97.3 % in the initial stage, and the total melting time was reduced by 28.36 %. The high temperature and velocity of the heat transfer fluid enhanced the heat storage rate by up to 40.6 %. Moreover, the bamboo-joint structure increased the heat transfer area of the system and induced fluid disturbances within the internal flow channels, thereby improving heat transfer. Finally, the results of the orthogonal experiments indicated that the inlet temperature of the heat transfer fluid had the greatest impact on the heat storage rate, with a lesser effect on the performance evaluation criterion (PEC). In most cases, the PEC of the bionic pipe exceeded that of the smooth pipe (without bamboo joints). This study provides valuable insights into the bionic design of phase change energy storage systems.