Numerical simulation of CaCO₃/CaO charging process in a spiral coil reactor

A reliable energy charging and discharging reactor plays a significantly important role on performance of a thermochemical energy storage system. The traditional reactors, such as fixed bed reactors, and fluidized bed reactors, suffer from terrible drawbacks including notorious heat transfer or back mixing. Accordingly, this study aims to propose a spiral coil reactor used for thermochemical energy storage system. The CaO/CaCO3 reverse reaction is selected as reaction model to numerically analyze variation of temperature, pressure drop, and reaction rate in the reactor. The results indicated that (1) heat transfer in the spiral coil reactor was affected by secondary flow; (2) the pressure drop increases with an increase in reaction temperature; (3) the maximum reaction rate occurs in the dilute phase of the reactor and the minimum reaction rate occurs in the dense phase of the reactor; finally, (4) the higher reaction temperature has a positive effect on the reaction rate. Overall, the main contribution of this study is the design of a spiral coil reactor which is expected to serve as a useful guideline for the future development of thermochemical energy storage reactor.