Modeling with experimental verification is presented for a novel Perforated Plate-Fin Absorber (Perforated Fin Absorber), developed for utilization in aqua-ammonia absorption chillers and heat pumps. The Perforated Fin Absorber’s (PFA) unique construction provides high heat and mass transfer efficiencies and simple fabrication, necessary for the residential and small commercial absorption cooling markets.
The PFA is comprised of a perforated fin sandwiched between cooling channels augmented with offset strip fin. Counter flow, falling film absorption (solution down, vapor up) occurs in the perforated fin cavity. The perforations are sized and spaced to prevent flooding and provide solution distribution. Coolant flow in the offset-strip fin cavities is counter to the solution flow.
The PFA was modelled using a combined heat and mass transfer analysis. Two laboratory prototypes were constructed and tested over a range of solution flow rates and concentrations. The experimental data was utilized to verify and calibrate the design model. Experimental results verify that the PFA geometry provides very high absorption rates over a wide range of operating conditions.