采用R1234ze(E)/离子液体工质对的吸收式制冷循环性能分析  

Performance Analysis on the Absorption Refrigeration Cycle Using R1234ze(E)/Ionic Liquids as Working Pairs

作　　者：张垚 朱山杉 王晓坡[1] 孙艳军[1] ZHANG Yao;ZHU ShanSHan;WANG Xiaopo;SUN Yanjun(Key Laboratory of Thermo-Fluid Science and Engineering, Ministry of Education, Xi'an Jiaotong University,Xi'an 710049,China)

机构地区：[1]西安交通大学热流科学与工程教育部重点实验室,西安710049

出　　处：《西安交通大学学报》2019年第5期9-15,共7页Journal of Xi'an Jiaotong University

基　　金：国家自然科学基金资助项目(51776170)

摘　　要：针对传统吸收式制冷工质对H_2O/LiBr和NH_3/H_2O等存在的问题,且含离子液体的工质对是一类有潜力的新型吸收式制冷工质对,选取烯烃类制冷剂R1234ze(E)与3种离子液体[Bmim][PF_6]、[Hmim][PF_6]和[Omim][PF_6]组成的工质对在单效吸收式制冷循环中的性能展开了研究。首先,运用NRTL活度系数模型关联了3种工质对的相平衡数据,建立了相关的热力学模型;其次,通过建立的热力学模型分析了不同发生温度、蒸发温度和冷凝温度时工质对的循环倍率、稀溶液与浓溶液的浓度差、系统性能系数以及■效率等的变化规律;最后,通过与文献中的R1234ze(E)以及其他离子液体(包括[Hmim][Tf_2N]、[Omim][BF_4]、[Hmim][BF_4]和[Emim][BF_4]等)组成的工质对在吸收式制冷循环中的性能进行了对比。研究结果表明:在冷凝温度为30℃时,3种工质对的性能在发生温度70℃时达到最大值,循环的■效率在65℃时达到最大,且工质对R1234ze(E)/[Omim][PF_6]的性能系数最大,可达到0.21,其■效率为0.089;R1234ze(E)/[Hmim][Tf_2N]系统性能最优,R1234ze(E)/[Emim][BF_4]的性能最低。研究结果可为后续新型制冷工质对在吸收制冷循环中的实际应用提供一定的参考。Traditional refrigerant-absorbent pairs, such as H2O/LiBr or NH3/H2O used in the absorption refrigeration system, have some drawbacks, and some of the mixtures including ionic liquids are considered as promising alternative working pairs. The performance of the single-effect absorption refrigeration system using R1234 ze(E)/[Bmim][PF6], R1234 ze(E)/[Hmim][PF6], or R1234 ze(E)/[Omim][PF6] as the working pair was investigated in the present work. Firstly, the NRTL activity coefficient model was used to correlate the experimental vapor-liquid equilibrium data, and the thermodynamic models of the absorption cycles were also established. In addition, the circulation ratio, mass concentration difference between strong and weak solutions, coefficient of performance and exergy coefficient of the cycle were analyzed at different generation temperatures, evaporation temperatures and condensation temperatures. At last, the performances of the refrigeration system based on R1234 ze(E) with other ionic liquids(including [Hmim][Tf2N],[Omim][BF4],[Hmim][BF4] and [Emim][BF4]) reported in the literatures are compared with the results of this work. The results show that when the condensation temperature is 30 ℃, the maximum coefficient of performance and the maximum exergy coefficient of the cycle can be attained at the generation temperatures of 70 ℃ and 65 ℃, respectively. And at this condition, the R1234 ze(E)/[Omim][PF6] pair has the highest coefficient of performance of 0.21, and the exergy coefficient is 0.089. The R1234 ze(E)/[Hmim][Tf2N] pair has the highest performance, but that for R1234 ze(E)/[Emim][BF4] is the lowest. This study may provide useful information for the application of new working pairs to the absorption refrigeration systems.

关 键 词：吸收式制冷 R1234ze(E) 离子液体 性能分析 

分 类 号：TB651[一般工业技术—制冷工程]