Structure optimization of a novel porous tree-shaped fin for improving thermochemical heat storage performance

Thermochemical heat storage is a promising solution for large-scale and longtime energy storage, while the poor heat and mass transfer performance of reactors limits its wide application. In this work, a new porous tree-shaped fin is proposed and used in a thermochemical heat storage reactor to improve both the heat and mass transfer performance. The heat storage characteristics are numerically investigated and compared to the reactors with radial fin and traditional tree-shaped fin. The results show that the charging time of the porous tree-shaped fin reactor under half fin amount is only 16.9% higher than that of the tree-shaped fin reactor, while the discharging time is 39.0% less. After that, structures of the new fin and tree-shaped fin are optimized. It is found that the optimized porous tree-shaped fin reduces charging and discharging time by 26.7% and 15.6% compared with the non-optimized one. Moreover, the discharging time of the optimized porous tree-shaped fin reactor is 56.8% less than that of the optimized tree-shaped fin reactor, while their charging time is almost the same. In short, the porous tree-shaped fin overcomes the drawbacks of previous fin structures that disable to strengthen mass transfer in reactors and exhibits excellent heat storage performance, which is worth considering in practical applications.