Energy storage comparison of sorption systems for cooling and refrigeration

A comparison between different sorption systems (binary mix only) such as absorption, adsorption and solid/gas reaction is presented with relation to their storage capacity for cooling. So as to be complete, phase change material (PCM) storage capacity has been added. The results are presented in kWh per kilogram of the total mass of the species involved in the cycle: the refrigerant fluid and the sorbent. In order to make a real condition comparison, two simple case studies have been made using temperatures that are compatible with a solar heat source. It appears that for negative temperatures, solid/gas reaction with ammonia has the best capacity. Storage with phase change material appears to be quite competitive even if a little less efficient. For positive temperatures. the best storage capacity is for water (working fluid) in absorption with NaOH as absorbent and in reaction with CaCl2, MgCl2 and Na2S as salt. (C) 2001 Elsevier Science Ltd. All rights reserved.