Pelton Wheel Turbine of Hydro Power Plant

Pelton Wheel Turbine of Hydro Power Plant

1. Pelton wheel has a rotor equipped with buckets along the whole periphery. The buckets used are elliptical in shape.
2. Refer Figure A In these type of turbines the total available head of water is first converted into kinetic energy and the water having this type of large kinetic energy is directed to impinge on the buckets by means of strong water jet through one or two jets.
3. Due to impact of water on the buckets of rotor, it will start turning or rotating.
4. The buckets are formed in two halves with a splitting at the centre in such a way that the jet after hitting in the centre deflects sideways and then falls into the tail race at a low velocity which is of the order of about 10% to 15% of the initial velocity.
5. For making use of available energy in water properly, the velocity of the discharge water should be less as possible as it can be In order to increase the output power number of jets may be increased upto 4 and may be spaced at equal distance along the circumference of the wheel as shown in Figure A (ii).
6. The increase in number of nozzles requires the bending of water pipe supplying water to these jets, which cause disturbance in water flow. Hence, for increasing the power output, double wheels may be used instead of increasing the number of nozzles.