On Friday, March 9, 2018, Lauren Farcot, a doctoral student in Energy and Process Engineering at the Laboratory for Optimization of Design and Environmental Engineering (LOCIE), will defend her thesis entitled "Study and analysis of a thermochemical heat storage system with a separate reactor." The defense will take place at 9:30 a.m. in the boardroom on the 2nd floor of Building 8C ( formerly the Chartreuse building) on the Bourget-du-Lac campus.
Thesis summary
Thermo-chemical storage systems are proving to be good alternatives to current technologies for seasonal or inter-seasonal heat storage, as energy is stored in the form of chemical potential and therefore there are no heat losses during storage. A large number of studies have been conducted on the development of thermochemical reactors integrated into the storage system, and few studies have been conducted on technologies involving reactors separate from the storage tank. However, the latter have the advantage, among others, of separating the thermal power of the reactor from the storage capacity of the facility, which would increase storage density.
This study examines the development of a moving bed thermochemical reactor operating with hydrated salts in humid air, suitable for heat network applications. A prototype reactor, developed and built during this study, was used to analyze the reactor's operation. Among other things, this study highlighted the impact of preferential air passages on reactor performance (temperature and power), as well as the importance of the steam content of the air at the reactor inlet on this performance. It also appears that the circulation of the solid significantly lowers the equilibrium point reached by the reaction.
In addition, two mathematical models were developed: a 1D analytical model and a 2D model that takes into account mass and heat transfer phenomena within the reactive zone. The 2D model, validated with experimental results, was used with COMSOL Multiphysics finite element simulation software to conduct a theoretical study of the reactor's operation and performance. This numerical study focused on the influence of operating conditions (air flow rate and humidity, solid velocity) on the performance and efficiency of the system and enabled a comparison of fluidized bed reactors with fixed bed reactors, commonly developed for thermochemical storage applications. This study demonstrated the importance of regulating solid velocity in order to optimize the performance of the moving bed reactor.
This study as a whole has highlighted the advantages and limitations of a moving bed reactor for thermochemical storage applications.