Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 30318
Exergy Analysis of a Solar Humidification- Dehumidification Desalination Unit

Authors: Mohammed A. Elhaj, Jamal S. Yassin

Abstract:

This paper presents the exergy analysis of a desalination unit using humidification-dehumidification process. Here, this unit is considered as a thermal system with three main components, which are the heating unit by using a solar collector, the evaporator or the humidifier, and the condenser or the dehumidifier. In these components the exergy is a measure of the quality or grade of energy and it can be destroyed in them. According to the second law of thermodynamics this destroyed part is due to irreversibilities which must be determined to obtain the exergetic efficiency of the system. In the current paper a computer program has been developed using visual basic to determine the exergy destruction and the exergetic efficiencies of the components of the desalination unit at variable operation conditions such as feed water temperature, outlet air temperature, air to feed water mass ratio and salinity, in addition to cooling water mass flow rate and inlet temperature, as well as quantity of solar irradiance. The results obtained indicate that the exergy efficiency of the humidifier increases by increasing the mass ratio and decreasing the outlet air temperature. In the other hand the exergy efficiency of the condenser increases with the increase of this ratio and also with the increase of the outlet air temperature.

Keywords: Desalination, Solar, Exergy analysis, condenser, humidifier

Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1335552

Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2014

References:


[1] H. Muller-Holst & W. Scholkepf,” Multi effect humidification seawater desalination using solar energy or waste heat- various implementation of a new technology”, Bavarian Center for applied Energy Research, Munchen, Germany/324-STOH10.
[2] F. A. Van Vught, Thermodynamics and Sustainable development, The use of exergy analysis and the reduction of irreversibility, R. L. Cornelissen, 1997, The Netherlands.
[3] Michael J. Moran & Howard N. Shapiro, Fundamentals of Engineering Thermodynamics, John Wily & Sons, Inc., USA, 2004.
[4] Adrian Bejan, Advanced Engineering Thermodynamics, John Wily & Sons, Inc., Singapore, 1988.
[5] Masanori Shukuya & Abdelaziz Hammache, Introduction to the Concept of Exergy- for a better understanding of Low-Temperature-Heating & High- Temperature-Cooling Systems, VTT Technical Research Center of Finland, Finland, 2002.