Adsorption and Refrigeration Performance of Ammonia-Composite Adsorbent Working Pair

Composite absorbent (CAds-AC-15) mainly used activated carbon and CaCl₂ as the resources for adsorption refrigeration were prepared by the mixed method, and the content of activated carbon in CAds-AC-15 was 15%. Adsorption isotherms of ammonia on CAds-AC-15 were determined by positive gravimetric method. Adsorption - desorption cycle performance and cooling characteristics of CAds-AC-15-ammonia working pair was evaluated by self-made adsorption - desorption measuring device. Experimental results show that the equilibrium capacity of ammonia on the CAds-AC-15 is up to 1.136kg/kg_ads at 30□, which is 5% lower than that of CaCl₂. With the conditions of adsorption temperature 30□, ammonia evaporation pressure 0.25 MPa, desorption temperature 300□, the performance of CAds-AC-15- ammonia working pair is stable after repetitious adsorption-desorption cycles, adsorption capacity of ammonia on the CAds-AC-15 and its cyclic adsorption capacity is 0.55˜0.65 kg/kg and 0.2˜0.25 kg/kg, respectively. The cooling capacity is up to 328.38kJ/kg_ads, which is twice as high as CaCl₂ - ammonia working pair.