Numerical investigation of a shell-and-tube thermochemical reactor with thermal bridges: Structurale optimization and performance evaluation

• Published in: Renewable energy 2023-04, Vol.206, p.1212-1227
• Main Authors: Wang, Chengcheng, Yang, Hui, Tong, Lige, Nie, Binjian, Zou, Boyang, Guo, Wei, Wang, Li, Ding, Yulong
• Format: Article
• Language: English
• Subjects: Charging and discharging performance; Numerical simulation; Reactor; Thermal bridge; Thermochemical energy storage
• ISSN: 0960-1481
• DOI: 10.1016/j.renene.2023.02.080

Thermochemical heat storage is a key technology to solve the mismatch between supply and demand of renewable energy and realize long-term energy storage. This work is concerned about a shell-and-tube thermochemical energy storage reactor and its aim is to address a challenge associated the low reaction rate from the tube centre of the reactor due to low thermal conductivity of the storage material. We proposed the integration of porous copper thermal bridges into the reactor and examined the performance enhancement with a validated mathematical model. By optimizing the structural parameters (numbers, thickness, and porosity) of the thermal bridge, the discharging rate and water temperature of the reactor can be maximized while the fan's electricity consumption is reduced. The results show that, with the addition of the thermal bridges with optimal structural parameters, the total heat release and water peak temperature lift can be increased by 11.33% and 39.75%, respectively, with the peak outlet water temperature reaching 59.02 °C. Reducing air velocity from 0.428 m/s to 0.107 m/s, the fan's electricity consumption can be reduced by 85.07% and 91.72% in the charging and discharging processes, which can be reduced by another 62.34% and 16.55%, respectively, after adding the thermal bridge. •Porous thermal bridges integrated into a shell-and-tube thermochemical reactor (TCR).•Optimal numbers, thickness and porosity of thermal bridges were obtained.•Fan's electricity consumption (FEC) proposed as TCR performance evaluating indicator.•Improvement of TCR reaction rate and reduction of FEC achieved simultaneously.