Why nozzle is used in impulse turbine?

Why nozzle is used in impulse turbine?

The nozzles are used to increase the kinetic energy of the water and to spray water to the blades of the turbine. This nozzle forms a jet with high velocity. This indicates the flow of water towards the blade in a particular direction. In an impulse turbine, single or multiple nozzles may be used.

Is there nozzle in reaction turbine?

A reaction turbine is constructed of rows of fixed blades and rows of moving blades. The fixed blades act as nozzles. The moving blades move as a result of the impulse of steam received (caused by a change in momentum) and also as a result of expansion and acceleration of the steam relative to them.

What is the main difference between reaction turbine and impulse turbine?

The main differences between Impulse and Reaction turbines are, all hydraulic energy is converted into kinetic energy by a nozzle in the Impulse turbine and whereas In Reaction turbine Only some amount of the available energy is converted into kinetic energy.

Which is more efficient impulse or reaction turbine?

Reaction turbines are more efficient as compared to the impulse turbines. The reaction turbine has more blades compared to the impulse turbine. The rotor blades turn around as the steam moves past them. In a reaction turbine, the direction of the steam remains the same.

What is impulse turbine give the working principle of an impulse turbine?

Impulse turbine works on the basic principle of impulse. When the jet of water strikes at the turbine blade with full of its speed, it generates a large force which used to rotate the turbine. The force is depends on the time interval and velocity of jet strikes the blades.

For which turbine nozzle is used?

All gas turbine engines have a nozzle to produce thrust, to conduct the exhaust gases back to the free stream, and to set the mass flow rate through the engine. The nozzle sits downstream of the power turbine.

Where is impulse turbine used?

An impulse turbine is used for high head hydroelectric power plants. An impulse turbine is a turbine that is driven by high-velocity jets of water. It is named as impulse turbine for the fact being that the resulting impulse from high velocity jets are used to spins the turbines.

Where are reaction turbines used?

Reaction turbines are generally used for sites with lower head and higher flows and are the most common type currently used in the United States. The two most common types of reaction turbines are Propeller (including Kaplan) and Francis. Kinetic turbines are also a type of reaction turbine.

Why draft tube is used in reaction turbine?

It is one of the important component of reaction turbine and connects runner exit to tail race. The main functions of draft tube is to allow the installation of turbine above the tail race level without loss of head and to convert major part of kinetic energy coming out of runner into pressure energy.

Why impulse turbine is better than reaction turbine?

Impulse turbines do not need a pressure chamber around the rotor because the nozzle generates the fluid jet before it reaches the rotor blades. Newton’s second law describes the energy transfer in impulse turbines. Impulse turbines are most efficient for use with low flow and high inlet pressure.

Where are impulse turbine used?

Impulse turbines are most efficient for use in cases where the flow is low and the inlet pressure is high. Reaction turbines develop torque by reacting to the gas or fluid’s pressure or mass. The pressure of the gas or fluid changes as it passes through the turbine rotor blades.

What are the disadvantages of impulse turbine?

Disadvantages Of Impulse Turbine:

• It is very costly to install.
• Its efficiency decreases with time.
• The size of this turbine is large as compared to other types.
• This turbine works only in high heads which is difficult to control.