Subject: Fluid machinery (SEMESTER + GATE).

*Introduction and classification of fluid machines:

fluid machinery:- 

• In fluid machinery we study about application of thermodynamics and fluid mechanics .

Fluid machines:-

 

• It is a device which converts the energy stored by a fluid into mechanical energy (or ) vice versa.

• the energy stored by a fluid mass appears in the form of

                                                                                             a. Potential energy

                                                                                              b. Kinetic energy

                                                                                              

                                                                                               c. Molecular energy

• Machines using liquid ( mainly water as a working substance ) are termed as hydraulic machines.

Fluid machines can be mainly classified into two types.

1. power producing machine

2. power absorbing machine

1. power producing machines are :-

a. Turbine

i. impulse turbine

ii. pelton turbine

iii. Reaction turbine

iv. Francis turbine

v.  Kaplan turbine / propeller turbine

2. power absorbing machines are:-

a. Pump / compressor

i. Positive displacement.

• Reciprocating / gear pump
• Rotodynamic pump
• centrifugal pump

* Hydroelectric power plants:-

Hydroelectricty:-

• It is the most widely used form of renewable energy .

It consists of mainly 5 parts:-

1. Dam and reservoir

2. Control gate

3. Penstock

4. water turbine

5. Generator

6. surge tank

 

1. Dam and reservoir:

• Dam means sufficient water storage at some height.
• the height of water level ( called a water head ).
• through this head we determines how much potential energy is stored in it.

2. Control Gate:

• Control gates are controlling the flow of water ( first water from the reservoir is allowed to flow through  the penstock  and to the turbine).
• If the control gate is fully opened , the maximum amount of water is released through the penstock.

3. Penstock:

• Penstock converted the potential energy of water into kinetic energy and it flows down through the  penstock due to gravity.

4. Water turbine( or )hydraulic turbine:

• Flow of water from the penstock is taken into the water turbine.
• Turbine converts hydraulic energy into mechanical energy. 
• The turbine is mechanically coupled to an electric generator.
• turbine moves through the kinetic energy of water.

5. Generator:

• A generator is mounted in the powerhouse and it is mechanically coupled to the turbine shaft.
• if turbine blades are rotated then they drives the generator,and the electricity generated.

6.Surge Tank:

• It is a small reservoir which is open at the top .
• it is fitted between the reservoir and the powerhouse.