On Friday, March 9, 2018, Lauren Farcot, a PhD student in Energetics and Process Engineering at the Laboratoire d'Optimisation de la Conception et Ingénierie de l'Environnement (LOCIE), will defend her thesis "Étude et analyse d'un système de stockage de chaleur thermochimique avec réacteur séparé". The defense will take place at 9:30 a.m. in the 2nd floor boardroom of Bâtiment 8C (formerly the Chartreuse building) on the Bourget-du-Lac campus.
Summary of the thesis
Thermochemical storage systems are proving to be good alternatives to current technologies for seasonal or inter-seasonal heat storage, as the energy is stored in the form of a chemical potential and therefore there are no heat losses during the storage period. A large number of studies have been carried out on the development of thermochemical reactors integrated into the storage system, and few studies have been carried out on reactor technologies separate from the storage tank. One of the advantages of the latter, however, is that the thermal output of the reactor and the storage capacity of the system can be dissociated, thereby increasing storage density.
This study focuses on the development of a moving-bed thermochemical reactor operating with hydrated salts under humid air, suitable for heat network applications. A prototype reactor, developed and built during the course of the study, was used to analyze reactor 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 air vapour titre at the reactor inlet on this performance. It also appears that solid circulation significantly lowers the equilibrium point reached by the reaction.
In addition, two mathematical models were developed: a 1D analytical model and a 2D model taking into account heat and material 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 reactor operation and performance. This numerical study focused on the influence of operating conditions (air flow rate and moisture content, solid velocity) on system performance and yield, and enabled a comparison of moving-bed reactors with fixed-bed reactors, commonly developed for thermochemical storage applications. This study demonstrated the importance of solid velocity control in optimizing moving bed reactor performance.
This study highlights the advantages and limitations of a moving bed reactor for thermochemical storage applications.