Desiccant Performance Evaluation of Desiccant-Coated Heat Exchanger-Based Heat Pump by Equilibrium Model

By combining the advantages of desiccant dehumidification and vapor compression refrigeration, the desiccant-coated heat exchanger-based heat pump (DCHE HP) is regarded as a promising alternative to the traditional vapor-compression air conditioning system (VCAC). Selecting proper desiccants from a large number of candidates is of great importance to improve the performance of DCHE HP. However, this task is challenging using current experimental or modelling strategies. In this work, we developed an equilibrium model to evaluate the power consumption of 39 DCHE HPs coated with different desiccants under various operating conditions. Eventually, five desiccants with low power consumption were selected. It was also demonstrated that under given operating conditions, the DCHE HP based on the five selected desiccants can save 21.3%–32.9% power compared with the VCAC. The power consumption of the DCHE HP is largely dependent on the heat of adsorption, the cyclical water uptakes and the remained moisture contents of the coating desiccants. It was further revealed that the moderate heat of adsorption, the larger cyclical water uptake and the lower remained moisture content are preferable for reducing the system energy demand. This work reported a quick evaluation of 39 desiccants for DCHE HP by an equilibrium model, which may also offer insights into the choosing and designing of desiccants for DCHE HP.