The model used for the following simulations was validated against a cylindrical source model, as well as by comparison with the models developed by Kujawa et al. [35] and Bu et al. [2]. A more specific breakdown of the model validation is detailed in Templeton et al. [34]. Additionally, the proposed model simplifies the velocity profile of the fluid within the heat exchanger to a uniform profile.This assumption was considered due to the laminar nature of the flow, the relatively low fluid velocity, and comparison with results obtained from implementing a parabolic velocity profile for the fluid in the inner pipe and outer annulus