Performance analysis of a K2CO3-based thermochemical energy storage system using a honeycomb structured heat exchanger

•Presents the thermal model for numerical simulation of potassium carbonate (K2CO3) as a thermochemical energy storage medium.•Presents the performance analysis of honeycomb heat exchanger with potassium carbonate as a thermochemical energy storage medium.•Presents the effects of honeycomb heat exchanger design parameters on thermochemical heat storage bed performance. The application of thermal energy storage using thermochemical heat storage materials is a promising approach to enhance solar energy utilization in the built environment. Potassium carbonate (K2CO3) is one of the potential candidate materials to efficiently store thermal energy due to its high heat storage capacity and cost-effectiveness. In the present study, a 3-dimensional numerical model is developed for the exothermic hydration reaction of K2CO3. The heat produced from the reaction is transferred indirectly from the thermochemical material (TCM) bed through the walls of the honeycomb heat exchanger to a Heat Transfer Fluid (HTF). A parametric study is conducted for varying geometrical parameters of the honeycomb heat exchanger. The obtained results indicate that the reaction rate and heat transport in the TCM bed strongly depends on the geometrical parameters of the heat exchanger. Reducing the cell size of the honeycomb heat exchanger up to a certain level provides better thermal transport as well as improved reaction rate of the TCM bed. The results of this study provide detailed insight into the heat release processes occurring in a fixed bed of K2CO3. The study is useful for designing and optimizing thermo-chemical energy storage modules for the built environment. [Display omitted]