(65a) Microchannel Based Integrated Desorber-Rectifier-Recuperator

Pacific Northwest National Laboratory has developed a family of microchannel based heat and mass transfer devices. Unit operations that have been developed include desorption, distillation, absorption, phase separation, and partial condensation. One of the promising attributes of microchannel based devices is the ability to combine several unit operations into a single device. This decreases the number of system components, eliminates piping, and reduces system size, weight and cost. The ability to combine unit operations is of particular interest in applications that require a minimal size and weight. One such application is portable cooling, where we have been developing microchannel based absorption cycle heat pump components for the U.S. Army. This ability to combine unit operations in a single device has been demonstrated with an integrated desorber-rectifier-recuperator for use in absorption heat pump cycles. This integrated device was developed using correlation based heat transfer models and finite element heat and mass transfer models. To better understand the desorption process, characterization experiments were conducted with a simplified single channel desorber, and this experimental data was used as design input for the integrated device. The 300 W scale desorber-rectifier-recuperator developed uses combustion heated air to generate refrigerant vapor; however, other heat sources such as exhaust from an internal combustion engine could be used. The performance of the desorber-rectifier-recuperator was tested in a breadboard system that includes a microchannel condenser, evaporator and absorber. The integrated desorber-rectifier-recuperator not only reduces system size but allows for more intensive heat integration and improved performance.