Experimental performance analysis on an adsorption cooling system using zeolite 13X/CaCl2 adsorbent with various operation sequences

In this study, an adsorption cooling system with a novel composite material (zeolite 13X/CaCl2) as the adsorbent and water as the adsorbate has been built and the system performance was studied experimentally under various working conditions. A much lower desorption temperature can be utilized to desorb the composite adsorbent when compared with the zeolite 13X adsorbent. Under the same operating condition, the SCP of the adsorption cooling system using the composite adsorbent is approximately 30% higher than that of the same system using silica-gel as the adsorbent. Although a longer adsorption/desorption phase time (cycle time) is required for the adsorption cooling system equipped with the composite adsorbent, it shows a better cooling performance than that of the silica gel adsorbent if a lower chilled water temperature is required. Various operating sequences (i.e. heat recovery, mass recovery, pre-heating and pre-cooling cycles) of the adsorption cooling system have also been investigated. The heat and mass recovery cycle has a huge improvement on the SCP and COP of the adsorption cooling system, improving the SCP and COP by about 126% and 125%, respectively. However, heat recovery requires fitting of extra equipment to the adsorption cooling system. Therefore, mass recovery together with the pre-heating and pre-cooling cycle is preferred, achieving the SCP and COP of about 106 W/kg and 0.16, respectively. It is about 129% and 100% increase compared with the basic cycle.