A hybrid multi-effect distillation and adsorption cycle
A hybrid multi-effect distillation and adsorption cycle
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DOI：
10.1016/j.apenergy.2012.12.007
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发表时间：
2013-04
期刊：
影响因子：
11.2
通讯作者：
K. Thu;Young-Deuk Kim;G. Amy;W. Chun;K. Ng
中科院分区：
文献类型：
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作者：
K. Thu;Young-Deuk Kim;G. Amy;W. Chun;K. Ng
本文介绍了一种简单的多效蒸馏(MED)和吸附(AD)循环混合海水淡化系统的开发，该系统工作在亚大气压和温度下。通过将传统的MED与AD循环相结合，两个循环的性能都得到了共生增强。性能的提高归因于(I)吸附剂再生温度的级联，这扩大了从盐水加热器发出的热能的使用；(Ii)通过AD循环从最后一个MED级抽出蒸汽，提供了将所有MED级的饱和温度降低到5°C的效果，从而清除了从环境中泄漏到MED级的热。混合循环的综合作用使海水淡化厂的水生产能力增加了近两倍。在本文中，我们通过模拟一个8级MED循环和一个吸附循环来演示混合循环，该循环用于从最后一个MED阶段直接提取蒸汽。利用硅胶的吸附性能(作为机械蒸汽压缩机)来降低MED级的饱和温度。模型利用了吸附剂+吸附物(硅胶+水)对的吸附等温线和动力学，以及质量、能量和浓度的控制方程。结果表明，在65~90℃的组合温度下，8级MED和AD循环的产水率比单独使用MED时提高了60%~2倍。性能比(PR)和增益产出率(GOR)也有显著提高。
This paper describes the development of a simple hybrid desalination system of a Multi-Effect Distillation (MED) and an adsorption (AD) cycle operating at sub-atmospheric pressures and temperatures. By hybridizing the conventional MED with an AD cycle, there is a symbiotic enhancement of performances of both cycles. The performance enhancement is attributed to (i) the cascade of adsorbent’s regeneration temperature and this extended the usage of thermal energy emanating from the brine heater and (ii) the vapor extraction from the last MED stage by AD cycle which provides the effect of lowering saturation temperatures of all MED stages to the extent of 5°C, resulting in scavenging of heat leaks into the MED stages from the ambient. The combined effects of the hybrid cycles increase the water production capacity of the desalination plant by nearly twofolds. In this paper, we demonstrate a hybrid cycle by simulating an 8-stage MED cycle which is coupled to an adsorption cycle for direct vapor extraction from the last MED stage. The sorption properties of silica gel is utilized (acting as a mechanical vapor compressor) to reduce the saturation temperatures of MED stages. The modeling utilizes the adsorption isotherms and kinetics of the adsorbent+adsorbate (silica-gel+water) pair along with the governing equations of mass, energy and concentration. For a 8-stage MED and AD cycles operating at assorted temperatures of 65–90°C, the results show that the water production rate increases from 60% to twofolds when compared to the MED alone. The performance ratio (PR) and gain output ratio (GOR) also improve significantly.