Analysis of floating type water wheel for pico hydro systems in Sri Lanka 

Abstract:

Sri Lanka is an island in the Indian Ocean and water is freely available around the island. Most of the people from rural areas are farmers and they cultivate in large areas. But they do not have electricity for pumping water to their agricultural. Normally channels are used to convey water into land but most of the time agricultural lands are situated at higher positions than the channels which make it difficult to transport water. The kinematic energy of water flow in those channels could be converted into useful energy, which in turn could be used for pumping water to higher elevations. For this purpose a simple method such as water wheel could be easily employed to generate electricity.

This study mainly focused on to carry out a feasible study based on the existing details of water wheel with related accessories and improves the overall working efficiency while developing a new system or modification of the present system and transfer the technology to the rural community.

A theoretical analysis of the water wheel was done based on 6 blades straight type wheel. The performance testing of water wheels in open channel were carry out for three types of blades and two different numbers of blades( 6 and 12).Based on the results It shows that 5% deviation between theoretical and experimental values of power and 36% deviation between theoretical and experimental values of R.P.M.

Also results obtained by testing of water wheels showed that experimental results of 12 blades water wheels were more powerful compared with 6 blades water wheels. It is approximately 2.5-3 times factor.

Based on this results calculations were carried out for 6 blade water wheel and predictions were done for a twelve wheel inclined blade wheel type considering the factors that affect the performance of the wheel. According to the test results, the average power output of the 12 blade curved type water wheel was 9.5 W. Solid works software was used to carry out the simulation to determine the stability and properties of blade.

According to analysis, floating type water wheel was found to be economical for rural areas because the cost of building a plant is US$ 340 and it is cheaper than other methods.