Use of Turbines in Hydroelectric Plants
INTRODUCTION
In hydroelectric power plant, turbine been used to generate power from reservoir of water. Turbine been selected by their characteristic curves based on the potential energy available in the water and the amount of power to be generated. Turbine is a type that develops torque by reacting to the pressure or weight of a fluid. The operation of reaction turbine can be describes by the Newton’s third law of motion that is for every action, there is an equal and opposite reaction. In this experiment, the main objectives are to study the characteristic curves of a reaction turbine.
Reaction turbine can be defined as a turbine with blades arranged to develop torque form gradual decrease of steam pressure from inlet to exhaust. When the velocity of a fluid is changed, the reaction forces are exerted like a simple nozzle when the fluid accelerated due to the changes in the cross sectional area. The kinetic energy of the fluid increases and since energy is conserved, the pressure of the fluid drops. This is meant that the pressure behind the fluid forces it through the nozzle causing it to speed up. The accelerated fluid in the direction of acceleration is required by force. Every force has an equal and opposite reaction so an equal and opposite force is exerted on the nozzle. There are three types of reaction turbine, in this experiment the radial flow reaction turbine been use. The radial flow reaction turbine has the liquid mainly in a plane perpendicular to the axis of rotation. A reaction turbine is moved by 3 main forces which are: The reactive force produced on the moving blades as the gas increases in velocity as it expands through the nozzle-shaped spaces between the blades. The reactive force produced on the moving blades when the gas changes direction The push or impulse of the gas impinging upon the blades. A reaction turbine is moved primarily by reactive force but also to some extent by direct impulse.
In hydroelectric power plant, turbine been used to generate power from reservoir of water. Turbine been selected by their characteristic curves based on the potential energy available in the water and the amount of power to be generated. Turbine is a type that develops torque by reacting to the pressure or weight of a fluid. The operation of reaction turbine can be describes by the Newton’s third law of motion that is for every action, there is an equal and opposite reaction. In this experiment, the main objectives are to study the characteristic curves of a reaction turbine.
Reaction turbine can be defined as a turbine with blades arranged to develop torque form gradual decrease of steam pressure from inlet to exhaust. When the velocity of a fluid is changed, the reaction forces are exerted like a simple nozzle when the fluid accelerated due to the changes in the cross sectional area. The kinetic energy of the fluid increases and since energy is conserved, the pressure of the fluid drops. This is meant that the pressure behind the fluid forces it through the nozzle causing it to speed up. The accelerated fluid in the direction of acceleration is required by force. Every force has an equal and opposite reaction so an equal and opposite force is exerted on the nozzle. There are three types of reaction turbine, in this experiment the radial flow reaction turbine been use. The radial flow reaction turbine has the liquid mainly in a plane perpendicular to the axis of rotation. A reaction turbine is moved by 3 main forces which are: The reactive force produced on the moving blades as the gas increases in velocity as it expands through the nozzle-shaped spaces between the blades. The reactive force produced on the moving blades when the gas changes direction The push or impulse of the gas impinging upon the blades. A reaction turbine is moved primarily by reactive force but also to some extent by direct impulse.
References: 1) http://www.brighthub.com/engineering/mechanical/articles/26551.aspx,16 March 2013 2) http://www.physicsclassroom.com/class/newtlaws/u2l4a.cfm, 16 March 2013 3) http://www.tpub.com/content/engine/14105/css/14105_164.htm, 16 March 2013