An enhanced model for the design of Diffusion Absorption Refrigerators

A steady state description of the thermal pump driving the Diffusion Absorption Refrigerator was integrated in the model previously proposed by the same authors. The thermal pump allows the DAR cycle to be activated, moving the strong mixture and separating the refrigerant from the weak one. So, the design parameters play a primary role in the DAR cycle performance in terms of COP. The enhanced model results were validated on a prototype built coupling a domestic 750 W-magnetron on a small purposely modified commercial DAR to activate the thermal pump. A maximum mismatch of 2.32% in the weak mixture mass flow rate and lower than 5% in COP between the predicted and measured data were found. The microwaves activated thermal pump produced a distinct reduction in the starting transient time of the refrigerator and for this reason it can be proposed as a valid candidate to be used as a rapid cooler in small refrigeration applications.