الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
Once the energy crisis of 1973, the recognition of serious limitation in conventional energy sources has turned new situation to be the utilization of solar energy . An overview of Egyptian energy situation has reflected the needs to use solar energy in power production.
This research introduces the salt gradient solar ponds(SGSPs) for power production, they have relatively low cost respect to other solar thermal techniques . SGSPs serve not only for collecting solar radiation but also for storing thermal energy in the same time . Thus , SGSPs may be directly or indirectly coupled to power cycles in order to produce mechanical or electrical power .
The objectivity of the present research is directed towards the stability and the optimization of the SGSP performance for a pond cited in Cairo Area (300 03” N, 310 15” R). Literature survey of SGSPs shows the needs to : (1)maximum SGSP performance , (2) optimum stable operation, (3) minimize the pond area per kw intercepted in bottom convective zone and (4) smooth –oyt of the variation , of temperature and heat load extracted, with respect to time. The research has analysed these items for a pond cited in Cairo area (300 02” N).
The optimum performance of a SGSP is established using mathematical models for both transient and steady states. The model presents the relation between the collection efficiency and pond variables : thicknesses of top convective, nonconvecting , and bottom convective zones, insulation and underground water level, and temperature rise per solar incident intensity on the pond.
The effective of each predescribed parameter are shown in set of curves in order to identify the optimum efficiency corresponding to that parameter.
The stability of falling SGSP is defined by the falling velocity and temperature gradients at top and bottom of the pond . The region of stable thickness of the nonconvective zone is approached in order to satisfy the optimum efficiency.
An adaptiation of a mirror field , in order to reflect solar radiation into pond region , has been analysed to meet minimizing of pond area per kw intercepted and smoothing out temperature and heat load levels. The analysis displays that the optimum mirror field shape is a vertical wedge reflector inclined 450, 450 to South direction towards East and West directions respectively. This mirror reflector enhances the solar beam to incident vertically downward at the pond surface, reduces the surface reflection loss. On other hand, the solar intensity input to pond surface has been increased .
Thus power generation using SGSP with a mirror field could meet the needs to use solar energy in power production.