Energy Storage Science and Technology ›› 2022, Vol. 11 ›› Issue (7): 2133-2140.doi: 10.19799/j.cnki.2095-4239.2022.0077

• Energy Storage Materials and Devices • Previous Articles     Next Articles

Simulation and the parameter influence relationship of the discharging process in a thermochemical reactor

Zhongbo LI1(), Jingxiao HAN1, Chengcheng WANG2, Hui YANG2, Na YANG2, Shaowu YIN2,3, Li WANG2,3, Lige TONG2,3(), Zhiwei TANG4, Yulong DING5   

  1. 1.Beijing District Heating Group, Beijing 100028, China
    2.School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing 100083, China
    3.Beijing Key Laboratory for Energy Saving and Emission Reduction in Metallurgical Industry, Beijing 100083, China
    4.Beijing University of Technology, Beijing 100022, China
    5.School of Chemical Engineering, University of Birmingham, Birmingham B152 TT, UK
  • Received:2022-02-15 Revised:2022-03-15 Online:2022-07-05 Published:2022-06-29
  • Contact: Lige TONG E-mail:digilee@126.com;tonglige@me.ustb.edu.cn

Abstract:

Thermochemical heat storage plays an important role in promoting utilization of renewable energy and achieving the "double carbon" goal due to its high heat storage density and nearly zero heat loss in the storage process. Thus, the design and performance optimization of thermochemical reactors are important. In this paper, we describe a two-dimensional simulation model constructed to investigate thermochemical reactor discharge using silica-gel as a heat storage material. By adjusting the model's parameters, e.g., the maximum water absorption, affinity coefficient, inhomogeneity, the preexponential factor, and the activation energy of the silica gel sphere, the results of a numerical simulation and experiment at reactor outlet temperature were in good agreement. We found that the affinity coefficient parameter, inhomogeneity parameter, and maximum water absorption of the silica gel sphere had more influence on the air outlet temperature among all considered parameters. The specific heat capacity was the least. When the heterogeneity parameter was increased from 1.2 to 2.8, the maximum air outlet temperature decreased from 140 ℃ to 70 ℃. The pre-exponential factor was found to have greater influence on air outlet temperature than activation energy. In addition, increasing the specific heat capacity of the silica gel reduced the maximum outlet temperature of the reactor and helped prolong the time required to reach the maximum outlet temperature. Combined with the experimental data of a small-scale reactor, the performance of a large-scale heat storage device can be predicted accurately after multiple charge and discharge cycles. Thus, the reactor and system design can be optimized.

Key words: thermochemical heat storage, reactor design optimization, numerical simulation, discharging

CLC Number: