Thermodynamic analysis of humidification dehumidification desalination cycles

Humidification–dehumidification desalination (HDH) is a promising technology for small-scale water production applications. There are several embodiments of this technology which have been investigated by researchers around the world. However, from a previous literature [1], we have found that no study carried out a detailed thermodynamic analysis in order to improve and/ or optimize the system performance. In this paper, we analyze the thermodynamic performance of various HDH cycles by way of a theoretical cycle analysis. In addition, we propose novel high performance variations on those cycles. These high-performance cycles include multi-extraction, multi-pressure and thermal vapor compression cycles. It is predicted that the systems based on these novel cycles will have gained output ratio in excess of 5 and will outperform existing HDH systems.King Fahd University of Petroleum and MineralsCenter for Clean Water and Clean Energy at MIT and KFUP

Heat Transfer Characteristics of Liquid Flow With Micro-Encapsulated Phase Change Material: Numerical Study

This numerical investigation fundamentally explores the thermal boundary layers’ characteristics of liquid flow with micro-encapsulated phase change material (MEPCM). Unlike pure liquids, the heat transfer characteristics of MEPCM slurry cannot be simply presented in terms of corresponding dimensionless controlling parameters, such as Peclet number. In the presence of phase change particles, the controlling parameters’ values change significantly along the tube length due to the phase change. The MEPCM slurry flow does not reach a fully developed condition as long as the MEPCM particles experience phase change. The presence of MEPCM in the working fluid slows the growth of the thermal boundary layer and extends the thermal entry length. The local heat transfer coefficient strongly depends on the corresponding location of the melting zone interface. The heat transfer characteristics of liquid flow with MEPCM are presented as well.</jats:p