Presentation on theme: "PELTON TURBINE Pelton Turbine is a Tangential Flow Impulse Turbine. The energy available at the inlet of the Pelton Turbine is only Kinetic Energy."— Presentation transcript:
PELTON TURBINE Pelton Turbine is a Tangential Flow Impulse Turbine. The energy available at the inlet of the Pelton Turbine is only Kinetic Energy The Pressure Energy of water is converted into Kinetic Energy when passed through the nozzle and forms into a high velocity water jet. This water jet is used for driving the Pelton Turbine or Pelton Wheel.
Water from the reservoir Flows through the Penstock To a nozzle at outlet Nozzle increase the KE of the water Water comes out in the form of jet Strikes the buckets (vanes) of the runner The runner will starts rotataing.
Pelton Turbine consists of a rotor (a circular disc), having equally spaced double hemispherical buckets (vanes) on its periphery. The spear is a conical needle, moving inside the nozzle will controls the amount of water flow through the nozzle and thereby regulating the amount of water striking the runner. The function of the casing is to prevent the splashing of the water and to discharge the water to the tail race. It is also acts as a safeguard against accidents.
FRANCIS TURBINE In modern Francis turbine, water enters the runner of the turbine in the radial direction and leaves in the axial direction, so the Modern Francis turbine is a mixed flow reaction turbine.
Water from the casing Enters the stationary guide wheel Guide wheel consists of guide vanes Which directs water to enter the runner (which consists of vanes) Water flows over the vanes sets the runner to rotate. Main parts are: 1.Casing 2.Guide mechanism 3.Runner 4.Draft Tube
CASING - Water from the penstock enters the casing which is of spiral shape. The area of cross section of the casing goes on decreasing gradually. The casing completely surrounds the runner of the turbine. The casing and runner are always full of water. The casing is usually made of cast steel, plate steel, concrete etc.
GUIDE MECHANISM – It consist of a stationary circular wheel all around the runner of the turbine. Stationary guide vanes are fixed on the guide mechanism. The guide vanes allow the water to strike without shock on the vanes which are fixed on the runner. By some suitable arrangement, the width between the two adjacent vanes of the guide mechanism can be altered thereby varying the amount of water striking the runner.
RUNNER– It is a circular wheel, having series of radial curved vanes. The surface of the vanes are very smooth, and shaped in such a way that water enters and leaved the runner without shock. The runner is keyed to the shaft. The runner are made of cast steel, cast iron or stainless steel.
Draft Tube – the pressure of at the exit of the runner of a reaction turbine is generally less than atmospheric pressure. The water is discharged to the tail race through a pipe or tube of gradually increasing area called the draft tube. The free end of the draft tube is submerged into the tail race. The draft tube partially convert discharge velocity into useful pressure head.
KAPLAN TURBINE If the vanes (3 to 8) fixed to the hub are adjustable, the turbine is known as Kaplan Turbine, named after Victor Kaplan, an Austrian Engineer. Kaplan Turbine are used when large quantity of water at low head is available.
MAIN PARTS OF KAPLAN TURBINE 1. Scroll Casing 2. Guide Vane Mechanism 3. Hub with Vanes or Runner of the Turbine 4. Draft Tube
The water from the penstock Enters the scroll casing Moves to the guide vanes Water turns through 90º Flows axially through the runner Runner rotates Water get discharged to the tailrace through the draft tube.