Key
2456
Conference Year
2014
Keywords
Adsorption cycle, Isotherm, Ethanol, Activated carbon, Specific cooling effect
Abstract
Adsorption equilibrium uptake of environment friendly refrigerant ethanol onto highly porous activated carbon based adsorbents has been experimentally investigated by using a magnetic suspension balance adsorption measurement unit (MSB-VG-S2). Adsorbents used in the present study are parent Maxsorb III, H2 and KOH-H2 surface treated Maxsorb III. Experiments have been conducted over adsorption temperatures range from 30 to 70 ºC and evaporation temperatures between -6 and 65 ºC. The Dubinin-Radushkevich and Dubinin-Astakhov adsorption isotherm models have been used to correlate adsorption isotherm data and to plot the pressure-temperature-concentration (P-T-W) diagrams of the assorted pairs. Isosteric heat of adsorption is estimated using the Clausius–Clapeyron equation. In the present study, the performance of adsorption refrigeration cycles using activated carbons/ethanol pairs has also been investigated employing a time-independent mathematical model. Results are compared with other adsorbent/refrigerant pairs found in the open literatures. Theoretical analysis show that the H2-treated Maxsorb III/ethanol adsorption refrigeration cycle can achieve coefficient of performance (COP) of 0.51 and specific cooling effect of about 374 kJ/kg at the evaporator temperature of -5 ºC in combination with heat source and heat sink temperatures of 100 and 30 ºC, respectively.
Thermodynamic analysis of absorption refrigeration cycles using parent and surface treated Maxsorb III/ethanol pairs