Assessing axial heat conduction in moving bed heat exchangers

An analytical solution is obtained for an energy model of a moving bed heat exchanger (MBHE) that includes axial heat conduction, subject to an external fluid at constant temperature. The problem formulation and nondimensionalization of the steady-state energy equations are presented for a parallel-plate system. The analytical solution is verified by examining it at the limit where axial heat conduction is neglected, and shown to simplify to expressions in the literature. The analytical solution is also compared to the results of a numerical solution under various conditions, and found to be in agreement. Finally, the solution is used to quantify the importance of axial heat conduction in a given MBHE, and the results are summarized in the form of error maps.