乙醇分割式机械蒸汽再压缩热泵精馏系统开发及性能研究  

Development and performance study of ethanol external separate mechanical vapor recompression heat pump distillation system

作　　者：廉文韬 吴小华[1] 杨鲁伟[2] 侯超[2] 宁旭丹 LIAN Wentao;WU Xiaohua;YANG Luwei;HOU Chao;NING Xudan(College of Mechanical Engineering,Beijing Institute of Petrochemical Technology,Beijing 102617,China;Technical Institute of Physics and Chemistry,Chinese Academy of Sciences,Beijing 100190,China;College of Energy and Power Engineering,Xi'an Jiaotong University,Xi'an 710049,China)

机构地区：[1]北京石油化工学院机械工程学院,北京102617 [2]中国科学院理化技术研究所,北京100190 [3]西安交通大学能源与动力工程学院,西安710049

出　　处：《流体机械》2025年第2期33-40,101,共9页Fluid Machinery

基　　金：中国科学院低温工程学重点实验开放课题(CRYO202112);北京石油化工学院重要科研成果培育项目(BIPTACF-002);重要科研成果培育项目(PCF-002);北京市教委科研计划(KZ202110017026)。

摘　　要：针对乙醇-水采用常规机械蒸汽再压缩(MVR)精馏技术无法达到节能精馏需求,兼顾精馏系统的安全性和经济性,开发了一种外部工质分割式MVR热泵精馏系统;构建了液相采用NRTL方程、气相采用RK方程的NRTL-RK组合模型,用于拟合物系的热力学性质;借助Aspen Plus软件,对常规精馏、常规MVR热泵精馏、直接压缩式MVR热泵精馏和外部工质分割式MVR热泵精馏等4种系统进行了模拟研究,对比分析了系统热力学性能、安全性等。结果表明,系统引入水作为循环工质,通过压缩水蒸气而非乙醇蒸汽,提高了系统的安全性。采用分割式结构,上精馏塔温差仅为3.54 ℃,有效减少了压缩机进出口温差;NRTL-RK组合模型的分析结果与试验数据对比表明,所构建的NRTL-RK组合模型可精确拟合乙醇-水物系的热力特性;所设计开发的外部工质分割式MVR热泵精馏系统,较常规乙醇精馏系统,可节约能源72.15%,可节约运行费用70.87%。该系统已在实际生产中得到成功应用,节能效果显著。研究结果可为乙醇精馏生产过程中的节能改造提供参考。Conventional mechanical vapor recompression(MVR)distillation technology cannot meet the energy-saving distillation requirements for ethanol-water,while balancing the safety and economy of the distillation system,taking into account the safety and economy of the distillation system,an external working medium splitting MVR heat pump distillation system was developed.A combined NRTL-RK model using NRTL equation in liquid phase and RK equation in gas phase was constructed to fit the thermodynamic properties of the system.With the help of Aspen Plus software,four kinds of systems,namely conventional distillation,conventional MVR heat pump distillation,direct compression MVR heat pump distillation and external working medium separation MVR heat pump distillation,were simulated and analyzed.The results show that the safety of the system is improved by introducing water as circulating working medium and compressing water vapor instead of ethanol vapor.With the split structure,the temperature difference of the upper distillation column is only 3.54℃,which effectively reduces the temperature difference of the compressor inlet and outlet.The comparison between the analysis results of the NRTL-RK combination model and experimental data shows that the constructed NRTL-RK combination model can accurately fit the thermodynamic characteristics of the ethanol-water system.Compared with the conventional ethanol distillation system,the designed and developed external working fluid split MVR heat pump distillation system can save 72.15%of energy and 70.87%of operating costs.The system has been successfully applied in actual production,with significant energy-saving effects.The research results can provide reference for energy saving transformation in ethanol distillation process.

关 键 词：乙醇 精馏系统 热泵 机械蒸汽再压缩(MVR) 热力学 

分 类 号：TB657.6[一般工业技术—制冷工程]