基于气隙式膜蒸馏的溴化锂吸收式制冷系统COP的优化  

COP optimization analysis of a lithium bromide absorption refrigeration system based on AGMD

作　　者：宋永 李恋 陈志[1] SONG Yong;LI Lian;CHEN Zhi(School of Chemical Engineering,Sichuan University,Chengdu 610065,Sichuan,China)

机构地区：[1]四川大学化学工程学院,四川成都610065

出　　处：《化工进展》2021年第S01期150-155,共6页Chemical Industry and Engineering Progress

摘　　要：针对传统的溴化锂吸收式制冷系统难以利用低品位热源的问题,将气隙式膜蒸馏(AGMD)技术引入到溴化锂吸收式制冷系统中,是使其能够利用低品位热源的一种新的工艺流程。本文根据已有的1H,1H,2H,2H-全氟癸基三乙氧基硅烷(FAS)-Al2O3管式复合膜的膜蒸馏性能数据,对典型的基于AGMD的溴化锂吸收式制冷系统进行了热力计算。结果发现制冷系统的性能系数(COP)值较小,仅为0.280,因而需要对其工艺流程作进一步的优化。经热力学分析确定了优化的方案:在膜发生器浓溶液出口处增加回路,从而改进了原制冷系统的工艺流程。研究结果表明,制冷系统的COP值会随着回流比的增大而增大。当回流比达到8时,COP值可达到0.765,相较于改进前的系统增大了1.74倍,大大改善了制冷系统的性能。Aiming at the problem that traditional lithium bromide absorption refrigeration systems can hardly use low-grade heat sources,we introduced the air gap membrane distillation(AGMD)technology into the system and established a new process to make use of low grade heat source.According to the existing AGMD data of the FAS(1H,1H,2H,2H-perfluorodecyltriethoxysilane)/Al2O3 tubular composite membrane,the thermal calculations were completed for a typical lithium bromide absorption refrigeration system based on AGMD.The results show that the coefficient of performance(COP)of the refrigeration system is small,only 0.280,so the process needs to be further optimization.After thermodynamic analysis,an optimum process was determined:adding a loop at the outlet of the membrane generator to improve the original process of the refrigeration system.The results indicate that the COP increases with the increase of the reflux ratio.When the ratio reaches 8,the COP could reach 0.765,which is 1.74 times greater than that of the system before improvement and greatly improves the performance of the refrigeration system.

关 键 词：气隙式膜蒸馏 溴化锂吸收式制冷 性能系数 优化设计 热力学过程 平衡 

分 类 号：TQ02[化学工程]