凹土-氯化钙复合吸附剂的制冷性能

摘要

采用凹凸棒粘土和氯化钙为主要原料,用溶解－混合法制备了复合吸附剂；采用正压重量法测量了复合吸附剂对氨的吸附等温线；并测定了吸附剂-氨工质对的制冷特性.结果表明:吸附温度30℃下,复合吸附剂对氨的平衡吸附量为1.1 kg/kg,与氯化钙对氨的平衡吸附量相当.在装填密度为600kg/m3,吸附温度为30℃、蒸发压力为0.25MPa、解吸温度为300℃条件下,对氨的吸附量达到0.89～0.92kg/kg,循环吸附量为0.55～0.58kg/kg,是纯氯化钙的1.7倍:复合吸附剂－氨工质对制冷量可达761.84kJ/kg,比氯化钙-氨工质对提高了70％.而且,复合吸附剂具有良好的吸附解吸稳定性能.%The composite absorbent is mainly consisted of attapulgite and CaCI2as the resources, which were prepared by the dissolution-mixed method, and the content of attapulgite in composite absorbent is 10%. Adsorption isotherms of ammonia on absorbents were determined by positive gravimetric method. Adsorption-desorption cycle performance and cooling characteristics of composite absorbent -ammonia working pairs was evaluated by self-made adsorption-desorption measuring device. Experimental results show that the equilibrium capacity of ammonia on the composite absorbent is up to l.lkg/kg at 30℃, which is equal to that of CaCl2. The conditions of loading density 600kg/m3, adsorption temperature 30℃, ammonia evaporation pressure 0.25 MPa, desorption temperature 300℃, adsorption capacity of ammonia in the composite absorbent and its cyclic adsorption capacity is 0.89-0.92 kg/kg and 0.55~0.58 kg/kg, respectively, which is 1.7 times than that of CaCl2-ammonia working pairs. The cooling capacity is up to 761.84kJ/kg, which is increased by 70% compared to CaCl2/ ammonia. What's more, composite absorbent has excellent adsorption and desorption stability.