Floating parabolic dish type solar water heating system, with heat sponging grid attached to the bottom is brought out
Ours being a tropical country, we are benefited with abundant solar energy more or less round the year. Even during monsoon period, when we have enough cloud cover, there is no dearth for solar energy. Unlike rain water harvesting, which has attracted all round attention, solar energy utilization for our day to day needs, has not caught up with public or government agencies. We have scarcity of power all round the year, and still lot of power is wasted, for heating water either for bathing, or washing clothes and utensils. Taking in to consideration the energy requirement considerations, and the expenses involved for consuming conventional electrical energy for heating purpose, we have come out a simple affordable design of solar water heating device exclusively for swimming pools. This consists of a parabolic dish type of solar energy collector, which reflects all the incident heat energy of sun, to the central heat absorbing tube, placed at the centre of the parabolic dish collector. The heat absorbed by the central copper tube is the transferred to the cold water of the swimming pool through a mushroom type of fins attached to the central pipe. This heat conducting fins, are located in the cold water, and is placed from the bottom of the solar water heater, through the use of four set screws, from the bottom of the dish collector as shown in the drawing. To increase the heat absorption, the outer surface of the central tube is painted in black chrome color. The floating solar water collector is located in the maximum depth area of the swimming pool as shown in the drawing. Same way, the inside surface of the parabolic dish is painted with heat rays reflecting color of white. Two motorized stirrers are placed in the maximum depth zone of the swimming pool to recirculate the heated water and to distribute the solar heat uniformly to the bulk water. The whole assembly is subjected by the gravitational forces in the downward direction, inward radial forces due to solar radiation on the parabolic disc upward thrust on the heat sponging elements submerged under the water surface, and so on. For small dish size, both the upward and downward forces are likely to balance resulting in a stable float of the assembly. But for larger size of parabolic dish, we may have to introduce an anti-submerging float in-between the dish collector and the heat sponging elements inside the water level, as shown in the drawing. Again this float size and thickness is dependent on the size of the dish. The floating disc/washer material can be light wood/thermo Cole or in inflated rubber tube of sufficient air pressure inside to keep the whole assembly floating overcoming the downward forces of gravity of the assembly.