Amr Seleem

Abstract

Fresh water shortage is now a global problem the world is facing, and solar stills address a sustainable solution towards such crisis. This study entails the importance of desalination, specifically solar distillation. Diffusion stills have been effective in water desalination. This work presents a model of the distillation process using vertical single-effect diffusion stills. In the provided models, two geometry patterns have been utilized: the flat sheets and the folded sheets. This study aims to evaluate the applicability of utilizing folded sheets on the performance of the still using wick and without wick. A semi-analytical model utilizing the flat sheet and the folded sheet have been developed to analyze the diffusion process. Furthermore, a software computer code using Engineering Equation Solver (EES) issued to solve the equations of the developed semi-analytical model. An experimental test rig has been constructed, and used for the validation of the semi-analytical model to find its best range of validity. Also, it is validated against former literature results. A good agreement is reached with feed rates of flow up to 0.0211 kg/m2-s. Moreover, a parametric study for the still utilizing flat sheets model is carried out to assess the performance of the still; it is found that the controllable parameters are:(i) hot plate temperature; (ii) cold plate temperature;(iii) diffusion gap thickness;(iv)feed water temperature; and (v) feed rate of flow; have an impact on the still’s productivity. The most dominant parameters that influence the productivity of the still are the hot plate temperature that ranges from (55- 90 °C), the diffusion gap thickness in range of (5-10 mm), the feed water temperature (20-50 °C), and the feed flow rate in range of (0.00694-0.0211 kg/m2-s). The experimental work utilizing folded-chevron pattern sheets, both with wick and wickless, have been carried out and have been compared to the flat sheets to assess still’s productivity. A comparative analysis has been conducted to evaluate the productivity; it is found that the folded sheet with wick has a higher productivity among other sheets. It indicates the superiority of the wicked folded over the wickless folded and the flat sheet. The folded pattern showed a higher performance by an average increase in the condensate to feed ratio by 27 % through the operating hot plate temperature that ranges from 60 to 90°C.

Department

Mechanical Engineering Department

Degree Name

MS in Mechanical Engineering

Graduation Date

2-1-2016

Submission Date

January 2016

First Advisor

Younan, Maher

Committee Member 1

El Haggar, Salah

Committee Member 2

El Morsi, Mohamed

Extent

70 p.

Document Type

Master's Thesis

Rights

The author retains all rights with regard to copyright. The author certifies that written permission from the owner(s) of third-party copyrighted matter included in the thesis, dissertation, paper, or record of study has been obtained. The author further certifies that IRB approval has been obtained for this thesis, or that IRB approval is not necessary for this thesis. Insofar as this thesis, dissertation, paper, or record of study is an educational record as defined in the Family Educational Rights and Privacy Act (FERPA) (20 USC 1232g), the author has granted consent to disclosure of it to anyone who requests a copy.

Institutional Review Board (IRB) Approval

Approval has been obtained for this item

Comments

This work has been supported by the Research Grant NPRP 5-161-2-053 from the Qatar National Research Fund

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