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Journal ArticleDOI

Process control in multi-stage flash desalination industry

13 Sep 2010-International Journal of Nuclear Desalination (Inderscience Publishers)-Vol. 4, Iss: 2, pp 174-183
TL;DR: In this paper, the authors identify various types of control loop available in an MSF plant, selection of control elements, type of control strategy needed for it and integrating the whole system for supervisory control.
Abstract: Process control is an essential part of the desalination industry that requires to be operated under optimum conditions to increase the lifetime of the plant and reduce the unit product cost. Improved process control is a cost-effective approach to energy conservation and increased process profitability. The Multi-Stage Flash (MSF) plant involves many complicated operations related to steam, chemicals and seawater. These include variable capacity, slow dynamics, deadtime characteristics due to certain load changes, significant effects of small deviations from design conditions on plant operation, effects of power plant output conditions on the desalination plant, instability due to disturbances in steam supply and water temperature variations. Keeping in view the above criticalities, the selection of an effective control system becomes inevitable. This paper aims at identifying various types of control loop available in an MSF plant, selection of control elements, type of control strategy needed for it and integrating the whole system for supervisory control.
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Journal Article
TL;DR: In this paper, the authors provide an overview of the state of the art and expected future outlook of thermal desalination processes, and discuss some of the challenges involved in the future developments of these processes.
Abstract: This article provides an overview of the present state of the art and expected future outlook of thermal desalination processes, and discusses some of the challenges involved in the future developments of these processes. It covers conventional thermal desalination processes, including multistage flash desalination and multiple effect evaporation, as well as several novel configurations that have recently been proposed.

31 citations


"Process control in multi-stage flas..." refers background in this paper

  • ...This energy recovery improves the process efficiency because of the increase in the brine recycle temperature to higher values (Ettouney et al., 1999)....

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  • ...Presence and accumulation of these gases results in corrosion of the condenser tubes and reduction of the overall heat transfer coefficient for the condenser tubes and, in turn, reduces the process efficiency and system productivity (Ettouney et al., 1999)....

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  • ...Vapour formation results in an increase of the brine stream salinity, which is limited to a maximum value of 70,000 ppm at the last stage (Ettouney et al., 1999)....

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  • ...The intake seawater stream is introduced into the condenser tubes of the heat reject section where its temperature is increased to a higher temperature by absorption of the latent heat of the condensing fresh water vapour (Ettouney et al., 1999)....

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Journal ArticleDOI
TL;DR: The conclusions point out the complexity of the real world control problem which behoves us to advocate the application of techniques such as self-optimizing control strategies and artificial intelligence leading to an integrated system of intelligent control.

29 citations

Journal ArticleDOI
TL;DR: In this article, the authors describe a novel method for the simulation of the multi-stage flashing (MSF) desalination process based on a modular simulator, CAMEL™, described in a series of publications by the same authors, which has been expanded by adding elemental software modules to simulate the MSF process.

11 citations


"Process control in multi-stage flas..." refers background in this paper

  • ...The plant is integrated and operated through a supervisory control and data acquisition system (Falcetta and Sciubba, 1999)....

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Journal ArticleDOI
TL;DR: All supervisory control functions as applied to Supervisory Control and Data Acquisition systems are implemented and for a large desalination plant preference is given to a reliable and dependable system even at the cost of slow data acquisition.

9 citations


"Process control in multi-stage flas..." refers background in this paper

  • ...However, a fully automatic analogue back-up system is still necessary in case of computer failure (Fareigh and Arazzini, 1985; Maniar and Deshpande, 1995)....

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