复合制冷循环在分布式能源利用中的热力学分析  

Thermodynamic Analysis of Hybrid Refrigeration Cycle for Distributed Energy Utilization

作　　者：孟学林[1] 尹丽[1] 李俊[1] MENG Xuelin;YIN Li;LI Jun(Guangxi Vocational & Technical Institute of Industry,Nanning 530001,China)

机构地区：[1]广西工业职业技术学院

出　　处：《化工技术与开发》2019年第6期46-51,共6页Technology & Development of Chemical Industry

基　　金：广西高校中青年教师基础能力提升项目(2017KY1171)

摘　　要：为了更好地在分布式能源系统中有效利用低品位太阳能,基于PR状态方程对R134a-DMF体系的热物性描述,本文采用AspenPlus过程模拟软件,对复合制冷循环进行了模拟计算,考察了压缩机出口压力的增加对低品位热利用性能的影响。结果表明,在一定的蒸发温度、冷凝温度、吸收温度和发生温度下,存在一个最佳压缩机出口压力区域,使得复合制冷的循环性能最优。同时,通过logp-T和logp-h热力学图,分析了复合制冷循环的节能机理。结果表明,在压缩循环中引入吸收循环,相当于降低冷凝压力,降低机械功消耗,复合制冷循环即可通过低品位热获得较好的制冷效果。这是在独立的吸收式制冷循环中不可实现的。热力学分析验证了模拟结果。Focusing on effective use of low-grade solar heat for distributed energy utilization, an absorption-compression hybrid refrigeration cycle was studied, in which 1,1,1,2-tetrafluoroethane (R134a)-dimethylformamide (DMF) was adopted as working fluid. The hybrid refrigeration cycle was simulated using the Peng-Robinson (PR) equation of state to calculate the thermophysical properties of R134a-DMF solution. The impacts of compressor pressure increasing on the low-grade solar heat utilization performance were investigated particularly, because of the significant interaction with the cycle performance. It was found that, there was an optimum compressor outlet pressure region with specified temperatures of evaporation, condensation, absorption and generation, where the hybrid refrigeration cycle had the maximum performance. Moreover, the energy saving mechanism for the hybrid refrigeration cycle was analyzed by thermodynamic diagrams of log p-T and log p-h. The results showed that introducing an absorption cycle to the compression cycle was equivalent to reducing the condensation pressure and reducing the mechanical work consumption, and lower temperature refrigeration effect could be obtained by low-grade heat in the hybrid refrigeration cycle, but it could not be achieved in the independent absorption refrigeration cycle. The analysis provided a validation of the hybrid refrigeration cycle simulation.

关 键 词：复合制冷循环 分布式能源 热力学分析 R134a-DMF 

分 类 号：TK511.3[动力工程及工程热物理—热能工程]