AbstractsEngineering

Shortage of drinking water in most parts of the world has been a growing concern in recent times. The situation has been getting worse in underdeveloped and developing countries due to sudden explosion in population growth and the growth in the industries. The natural resources for potable water are limited and unless a feasible solution is obtained in the near future, the ‘concern situation’ may turn into a ‘panic situation’. A possible solution for the shortage in drinking water is to use water from inexhaustible sources such as oceans and seas and make it potable using desalination process. However, the process of desalination is an energy intensive process which the poor countries can not afford. In recent times, the cost of fossil fuels has been skyrocketing. With the crude oil costing more than Rs.5200 (US$120) a barrel as on September 2008, even the rich countries like USA and the countries in the European Union are feeling the pinch of the energy cost. Alternate energy sources such as solar, wind, geo-thermal, hydrogen etc., have become the order of the day. These sources are renewable and are environmental friendly. More than one third of the populations of the world live in coastal areas. These areas get abundant amount of solar energy throughout the year. Utilization of this energy in desalination process would solve drinking water problem to a very great extent. However, construction of centralized desalination plants requires large amount of capital which the poor countries can ill-afford. An alternate solution would be to construct decentralized smaller plants that would require smaller capital to construct and easier to maintain. If the energy requirement is tapped from renewable sources such as solar, then the operational cost also becomes affordable for the poor countries. By taking care of the water requirement of the coastal areas through this process, one may save large amounts of money in transporting potable water from interior areas to the coastal areas. There would be enough water for the people living in the interior areas. The water bed level in the interior areas would gradually increase, thereby reducing the drinking water concerns significantly. In this thesis, a small scale stand alone power generation system for the desalination process is proposed that is suitable to provide clean potable water from sources such as sea water or brackish water. Solar energy is proposed as a source of energy for the proposed desalination system. This source is available in plenty in arid and semi-arid areas. It is free and is also friendlier to the environment. It is proposed to use solar energy in thermal form to obtain energy equivalent of ‘latent heat of vaporization’ for the vaporization process and in electrical form for operating the dc machines and electronic control units that are integral parts of the desalination system. The proposed desalination unit can be built as small as possible even to feed a single household’s requirement and hence can be conceptualized as decentralized…