Runner with bucket: – runner of Pelton wheel consists of a circular disc on Governing mechanism: – speed of turbine runner is required to be. This speed should also conforms to the power supply frequency. So this mechanism acts as a speed governing mechanism of Pelton wheel. Presentation on:Governing of Pelton WheelTurbine pump with oil sump Relay or control valve Servomotor with spear rod and spear Deflector mechanism.
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The governing achieved by changing the guide vane angles. It receives the pressurized oil from pump which is diverted towards the ports connected to pipe A or pipe B. When N is zero, the angular speed is zero and when N equals runaway speed, the output power is again zero.
It is a double acting cylinder which acts as hydraulic actuator. This is done by controlling the quantity of water flowing on the runner according to the load variations. The piston of the cylinder will be displaced towards left, thus forcing the oil through the pipe B into the relay valve and finally to oil sump.
If water rises above full level of reservoir water enters into spillway and discharge.
Presentation on:Governing of Pelton WheelTurbine
Once the normal turbine speed is restored, the main lever returns to its initial position. No control on flow of water. Thus, it is essential that the exact behavior of the unit under varying working conditions is predetermined.
Due to turning of guide vanes the space between two consecutive guide vanes would change. The piston of the cylinder will be displaced towards left, thus forcing the oil through the pipe B into the relay valve and finally to oil sump. The flow of water in side channel is either used as a cannel or it meets to river. Governing of Pelton WheelTurbine. It is double acting cylinder which acts as hydraulic actuator.
Presentation on:Governing of Pelton WheelTurbine – ppt video online download
It is temporary regulating reservoir. The guide vanes or wicket gate may be adjustable to allow efficient turbine operation for a range of water flow conditions. C engine Cylinder Piston Connecting rod. Therefore, a separate servomotor is provided to operate the runner blades which are few in number.
The downward movement of the piston in the control valve forces oil under pressure from the control valve to the left side of the piston in the servomotor. This curve goverbing obtained from records of average monthly flows. It can be seen by this mechanism, the linear motion of servomotor piston is converted into rotary motion of regulating ring.
It receives oil from relay valve say through pipe A.
It is driven by the turbine shaft through bevel gears. Transmission Hydraulic Systems Chapter 4 Introduction How the transmission develops hydraulic pressure How transmission generates, regulates and modifies.
Francis, Propeller or Kaplan turbine are employed. The plants are located that the water is taken from the river directly, and no pondage or storage is possible. Surge tank is built just before the valve house so that the severity of water hammering is reduced. The outlet is a specially shaped draft tube that helps decelerate the water and recover kinetic energy. Consequently, the rate of flow is decreased and normal speed is restored.
The large turbine diameter combined with the massive inertia of the water flowing through it makes precise control of rotational speed a critical concern. Guide vanes direct the water tangentially to the runner.
This results in an oscillating condition where by the turbine is constantly speeding up and slowing down. Penstock Valves and Gates. The maximum and minimum run-off during period. Since the governor is driven by the turbine shaft, its speed will also As a consequence, the flyballs of the governor will move inwards due to reduced centrifugal force on the balls.
Since H is constant, the peripheral speed of the turbine is constant and therefore, the discharge is independent of speed. Therefore in order to mecuanism constant speed of generator ,governing of turbine is required to maintain the constant speed of turbine with respect to load.
Sleeve moves downward, eplton. Total volume of discharge upto kechanism time, given by the area under the curve upto the time. Auth with social network: These are obtained by manufacturers by conducting experiments on models in a laboratory and by doing mechanusm tests on the site. Governing of Pelton WheelTurbine”— Presentation transcript: Proportional or directional valves controlled by the governor operate cylinders that open and close wicket gates or needle valves to adjust the flow of water to the turbine in order to maintain a constant turbine speed.
Speed vs power curve: Oil pump is a positive displacement type of pump like gear pump or axial piston pump.
Governing of Pelton – Free Download PDF
Its lower end is turned at right angle and horizontally taken out of dam. The discharge at any time during the period under consideration. Goverbing speed-efficiency curves for turbines are similar to speedpower curves. A centrifugal governor is used as the measuring element of the closed loop control system. Space between guide vanes will increase in one direction of rotation of regulating ring and space will decrease in its opposite direction of rotation.
The physical parameters controlling the performance of a turbine are speed N, power output P, head H, discharge Q, the position of gate opening nozzle opening or guide blade opening G, and the efficiency of the turbine. What is a Dam?
Fly ball of the governor moves upward, 2. To make this website work, we log user data and share it with processors. Capital cost required is low.