Performance optimization of a heat pump driven liquid desiccant dehumidification system using exergy analysis
Performance optimization of a heat pump driven liquid desiccant dehumidification system using exergy analysis
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DOI：
10.1016/j.energy.2020.117891
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发表时间：
2020-08
期刊：
影响因子：
9
通讯作者：
Qinling Zhang;Xiaohua Liu;Tao Zhang;Ying Xie
中科院分区：
文献类型：
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作者：
Qinling Zhang;Xiaohua Liu;Tao Zhang;Ying Xie
热泵驱动的液体除湿空调系统是目前公认的一种有效的空调调湿方法。采用火用损分析方法对液体除湿空调系统进行优化。根据火用损理论，将除湿空调系统的火用损分为热泵循环、蒸发器、冷凝器、传热传质组件和各种混合过程的火用损。提出了传热传质过程均匀性系数γ t和γω来描述传热传质驱动力沿整个系统沿着的均匀性。结果表明，基本横流系统的γ t和γω分别高达1.4和1.2。然后以降低火用损失为优化目标，对系统进行优化。在基本横流系统的基础上，进一步提出了改进的横流系统和改进的逆流系统，改进系统的γt（γω）分别降低到1.12（1.12）和1.04（1.01）。通过系统优化，系统的（火用）效率由基本横流系统的20.1%分别提高到21%和25%，COPsys由5.7分别提高到6.0和7.4。该分析方法对溶液除湿热泵过程的优化设计是有效的。
Liquid desiccant dehumidification system driven by heat pump is recognized as an efficient approach for humidity control in the air-conditioning system. The liquid desiccant dehumidification system is optimized by exergy destruction analysis method in the present research. According to the exergy destruction theory, the exergy destruction of a liquid desiccant dehumidification system is divided into exergy destructions arising from heat pump cycle, evaporators, condensers, heat and mass transfer modules and various mixing processes, respectively. The heat and mass transfer process uniformity coefficientsγtandγωare proposed to describe the uniformity of the heat and mass transfer driving forces along the whole system. It’s indicatedγtandγωof the basic cross-flow system are as high as 1.4 and 1.2. Then reducing the exergy destruction is chosen as the guideline to optimize the system. On the basis of the basic cross-flow system, the improved cross-flow system and the improved counter-flow system are further proposed.γt(γω) of the improved systems are reduced to 1.12(1.12) and 1.04(1.01), respectively. Owing to the system optimization, the exergy efficiency increases from 20.1% of the basic cross-flow system to 21% and 25% respectively,COPsysincreases from 5.7 to 6.0 and 7.4 respectively. The exergy analysis method is effective for an optimized scenario of a heat-pump driven liquid desiccant process.