The application of solar desalination for water purification in Cyprus

  • Soteris A. Kalogirou

    Student thesis: Doctoral Thesis


    This thesis initially reports on the water resources of Cyprus. From this analysis the need for desalination systems to provide fresh water, is established.

    A survey of solar desalination systems shows that there arc two broad categories of such systems; namely direct and indirect collection systems. The latter type is adopted and a multiple effect process is selected due to its low energy consumption, low equipment cost, simple sea-water treatment requirement and its suitability for variable steam supply conditions.

    The design of a parabolic trough collector system is presented based on previous work. Special consideration is given to the radiation intensity distribution on the collector receiver and the mode of tracking selection. The E-W horizontal mode is selected due to its small shadowing effects. Computer programs are developed for all the above analyses and for modelling of the steam generation system. The design of the complete desalination system is also presented.

    The collector performance tests show that the test slope and intercept are 0.387 and 0.638 respectively. The preliminary tests indicate the need to reduce start-up energy requirements. A modelling program is developed to optimise the design of the system's flash vessel and this is validated for both steady state and transient conditions. The optimum flash vessel dimensions and capacity reduced the system preheat energy by 30%.

    An economic analysis of the collector system is carried out followed by a feasibility study of using the system in a number of applications. It is shown that the system could be viable for the two larger applications (hotel and village) with a water price below 0.89 C£/m3 It is also shown that it is not cost effective to operate the system solely on solar energy due to a combination of the high system cost and the high percentage of inactive time.
    Date of Award1995
    Original languageEnglish
    SupervisorStephen Lloyd (Supervisor)

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