Ammonia Desorption in Microscale Fractal-Like Branching Flow Networks Available to Purchase

An experimental study is presented in which ammonia is desorbed from a binary mixture of ammonia and water using a network of microscale fractal-like branching channels. The objectives of the study are (1) to determine feasibility of desorption by boiling the fluid mixture inside a microchannel array, and (2) to quantify the rate of desorption as a function of applied heat flux and strong solution flow rate. The desorber is disk-shaped with an inlet plenum at the center and the flow network branching radially outward toward the edge of the disk. The flow network was chemically etched in a stainless steel disk with a nominal terminal branch hydraulic diameter of 88 μm. Inlet and exit mass flow rates, temperatures, pressures and mass fractions were measured along with the heat flux applied to the surface of the desorber disk. Results indicate that desorption rates and water vapor content in the refrigerant vapor stream increase with increases in heat flux and decrease with strong solution mass flow rate.