EXPERIMENTAL PERFORMANCE EVALUATION OF DESORBER IN A HYBRID ABSORPTION VAPOR COMPRESSION SYSTEM

Abstract

A single-effect absorption facility was designed and constructed to experimentally investigate the performance of a 3 kW mini-channel desorber using an R134a/POE32 solution mixture. The facility was fabricated to simulate a hybrid absorption/vapor compression system for an off-grid high temperature application utilizing an air-cooled absorber. Desorber design replicated the utilization of waste heat from a generator source. The effects of temperature, pressure, solution mass flow rate and refrigerant concentration variations on desorber and desorption performance were investigated and analyzed through vapor generation, circulation ratio, poor solution concentration, desorber mean heat transfer coefficient and quality difference. Desorber heat transfer coefficient enhancement was found to be a strong function of solution temperature, rising by up to 75% with a 30°C temperature increase. Due to poor absorber performance, increasing solution temperatures and mass flow rates did not result in a proportional desorber vapor generation enhancement, leading to a reduction in desorber quality difference.