Numerical and experimental investigation of multiple heat exchanger modules in cooling and desalination adsorption system using metal organic framework

The cooling and desalination adsorption system is a heat-activated system based on the solid sorption process. The main challenge in this system is concentrated to decrease the energy consumption of this system using a low desorption temperature (less than 90 degrees C) while maintaining a good performance. A scaled-up adsorption system using multiple heat exchanger modules packed with commercially available metal-organic framework material that operates at low desorption temperature, was numerically and experimentally investigated in the present paper. Three-dimensional and two-dimensional axisymmetric numerical models were developed to simulate heat and mass transfer phenomena considering the internal and external mass transfer in the adsorbent domains. Effects of the modules' connection options and vapor gap between modules on the system performance were examined. The highest coefficient of performance was achieved when connecting the modules in series, affected by the considerable reduction in the heating power. However, the increase in the effective amount of adsorbate resulted in the best specific cooling power when connecting the modules in parallel. Additionally, A scaled-up adsorption cooling/desalination system using 23.2 kg of Aluminium Fumarate packed in 16 modules was constructed and evaluated experimentally. The system produced desalinated water of 201 L/day and cooling capacity of 5.25 kW at the evaporator, condenser, and desorption water temperatures of 24 degrees C, 25 degrees C, and 85 degrees C, respectively. The specific daily water production decreased by 16.3% when the water salinity increased from 90 to 100,000 ppm, while the lowest specific electrical energy consumption of the proposed system is 1.87 kWh/m(3). The theoretical and experimental results will enable further scaling up of an efficient MOF adsorption system for cooling and water desalination.