الفهرس | Only 14 pages are availabe for public view |
Abstract Water plays a significant role in all daily activities and its consumption is increasing day by day as a result of the increased living criterions of humankind. Up to half of the world’s population is facing water crisis that are growing at an alarming rate, especially in arid and semi-arid regions of the world. During the past decade, there has been a significant reduction in the annual per capita share of freshwater in Egypt. This is indicated by an increase in population with the same freshwater sources. Future forecasts indicate that by 2025; the annual per capita of freshwater will fall to 500 cubic meters, half of the international normal level. The freshwater needs of mankind can be only met if the saltwater available in large quantities is diverted to drinking water by desalination. Thus, with the potential of solar energy available in Egypt (2100-2400 kWh/m”) and large .L saltwater resources from the Mediterranean Sea in the north and the Red Sea in the east, desalination has been found as an attractive and promising solution towards freshwater availability. Among many indirect non-membrane water desalination systems, a system based on the multi-effect evaporation (MEE) process consumes low thermal energy and is highly competitive with desalination systems driven by conventional energy. It can be used to provide clean water to more than a billion people who do not have water access or have water shortages, and prevent their health and economies threaten. The solar desalination system consists of solar evacuated tube collectors (ETC) and the MEE desalination unit which consist of horizontal tube, falling-film effects (heat exchangers) in sequential order, to produce fresh water through repeated steps of evaporation and condensation. Solar evacuated tube collectors provide sufficient thermal energy to heat up solar fluid which will then transfer its thermal power to the seawater in the first effect across the desalination unit and would raise it to the desired temperature then the solar fluid would be pumped back into the solar field for further heating. MEE desalination system performance depends on the weather conditions of the implementation location. This indicates the urgent needs for a design tool that could help in predicting the performance parameter of the desalination system at certain location before implementation decision. The essential standards for understanding the performance of the desalination system are; the productivity (rrr’zday), the performance factor (PF) which is the amount of fresh water produced specified to unit mass of heating source, the specific heat transfer surface area (SA) (m2/(kg/s)), which is the |