通过集成交叉复合抛物面聚光器在生物炭基定形稳定储热介质中实现低辐射地区太阳能直接吸收的可持续解决方案

Abstract Renewable energy to meet the low temperature thermal needs is need of the hour as it contributes to almost half of the consumption. The adoption of thermal energy storage can accelerate the share of renewable heat by improving reliability and efficiency. A novel thermal energy storage material is developed by encapsulating paraffin-based Phase Change Material (PCM) in porous biochar to improve thermal conductivity and prevent leakage. This composite is then placed in a rectangular cavity and radiated using a halide light source from top to mimic the actual solar heating. To reach a high level of irradiance a Cross Compound Parabolic Concentrator (CCPC) with a concentration of 4× has been designed and utilised. The work includes a comparative study of pure RT28 and RT28-softwood biochar composite. A solution is proposed to advance the applicability of latent heat energy storage, charged through direct solar absorption, by use of a well-designed CCPC under low radiation conditions. The composite with concentration melts 5.4 times faster as compared to non-concentration condition. Similarly, the melting is quicker in the composite as that of RT28 due to improvement of thermal conductivity by 80 %. CCPC integrated thermal energy storage can reach an average storage temperature of 89.7 °C with an irradiance of 540 W/m 2 . These findings could be helpful to accelerate the deployment of PCM based biochar composite for energy storage applications in the locations with low solar irradiance and short sunshine duration.