Field synergy analysis for heat and mass transfer characteristics in adsorption-based desalination and cooling systems

Adsorption-based desalination and cooling system has gained particular interests for low-grade heat harvesting. In this study, field synergy analysis is conducted to illustrate the complicated heat and mass transfer characteristics in an adsorption-based desalination and cooling system with finned-flat beds via a dynamical three-dimensional computational fluid dynamics model. Two field synergy angles alpha and beta reflecting the synergy effect of heat transfer and flow resistance with the adsorption driving force are examined. Results illustrate that smaller alpha and beta result in better adsorption performance. Furthermore, guided by the field synergy analysis, adsorbent bed configurations (fin diameter, fin pitch, fin shape, and fin arrangement) are optimized. The fork row arrangement results in a higher SCP and SDWP than that of the in-line arrangement. With the fin pitch of 20 mm and fin diameter of 12 mm, the system with fork-row arrangement demonstrates a SCP of 0.363 kW/kg and SDWP of 12.5 m(3) per ton silica gel per day, which is 6.6% higher than that of the in-line arrangement as the field synergy parameter between heat transfer and the driving force factor (alpha) is more predominant at a relatively smaller fin pitch.