Sustainable desalination technologies are the smart solution for producing fresh water
and preserve the environment and energy by using sustainable renewable energy
sources. Membrane distillation (MD) is an emerging technology which can be driven
by renewable energy. It is an innovative method for desalinating seawater and brackish
water with high quality production, and the gratitude is to its interesting potentials.
MD includes a transfer of water vapor from a feed solution to a permeate
solution through a micro-porous hydrophobic membrane, rejecting other non-volatile
constituents present in the influent water. The process is driven by the temperature
difference along the membrane boundaries. Different control applications and
supervision techniques would improve the performance and the efficiency of the MD
process, however controlling the MD process requires comprehensive mathematical
model for the distributed heat transfer mechanisms inside the process. Our objective
is to propose a dynamic mathematical model that accounts for the time evolution of
the involved heat transfer mechanisms in the process, and to be capable of hosting
intermittent energy supplies, besides managing the production rate of the process,
and optimizing its energy consumption. Therefore, we propose the 2D Advection-Diffusion Equation model to account for the heat diffusion and the heat convection mechanisms inside the process. Furthermore, experimental validations have proved
high agreement between model simulations and experiments with less than 5% relative
error. Enhancing the MD production is an anticipated goal, therefore, two main
control strategies are proposed. Consequently, we propose a nonlinear controller for
a semi-discretized version of the dynamic model to achieve an asymptotic tracking
for a desired temperature difference. Similarly, an observer-based feedback control
is used to track sufficient temperature difference for better productivity. The second
control strategy seeks for optimizing the trade-o between the maximum permeate flux production for a given set of inlet temperatures of the feed and the permeate solutions,
and the minimum of the energy consumed by the pump
ow rates of the feed
and the permeate solutions. Accordingly, Extremum Seeking Control is proposed for
this optimization, where the pump
flow rates of the feed and the permeate solutions
are the manipulated control input.
| Identifer | oai:union.ndltd.org:kaust.edu.sa/oai:repository.kaust.edu.sa:10754/583277 |
| Date | 12 1900 |
| Creators | Eleiwi, Fadi |
| Contributors | Laleg-Kirati, Taous-Meriem, Computer, Electrical and Mathematical Sciences and Engineering (CEMSE) Division, Shamma, Jeff S., Christofides, Panagiotis, Alouini, Mohamed-Slim, Ghaffour, NorEddine |
| Source Sets | King Abdullah University of Science and Technology |
| Language | English |
| Detected Language | English |
| Type | Dissertation |
| Rights | 2016-12-06, At the time of archiving, the student author of this dissertation opted to temporarily restrict access to it. The full text of this dissertation became available to the public after the expiration of the embargo on 2016-12-06. |
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