Design and Simulation of Flat Plate Collector With a Tube Rotation and Phase Change Materials Sn3N4-LiNO3-KNO3/Boron-Arsenide for Enhanced Efficiency

Abstract

Solar thermal energy is crucial in our transition to renewable energy sources. Recent studies have focused on enhancing the efficiency of solar collectors by minimizing thermal energy loss during absorption. A promising approach involves an innovative design that integrates phase change materials (PCMs) and rotating tubes to capture thermal energy more effectively. Advanced nitride-based salt hydrates, with boron-arsenide additives, enhance thermal performance of the collector. In a flat plate collector using composite PCMs, radiative heat loss decreases from 250 to 210 W (a 6% reduction) with tube rotation, while convective heat loss drops from 225 to 195 W (a 4% decrease). The decomposition rate of the novel PCMs is low, measuring only 0.5% at a maximum temperature of 850°C, with a specific heat capacity of up to 4.50 W/m K. This unique blend, including the Sn₃N₄-LiNO₃-KNO₃/boron arsenide mixture, enhances thermal conductivity by 30%, significantly improving thermal absorption rates. The exergy efficiency achieved with the Nano-enhanced phase change materials (NEPCM) and tube rotation reaches an impressive 90%. With tube rotation at 3 rad/min, the flat plate collector's efficiency improves by 22%, reaching an overall efficiency of 90% at a fluid flow rate of 25 kg/h. Simulations using Anaconda Jupyter Notebook and Python validate the effectiveness of both tube rotation and NEPCM in enhancing collector efficiency.