Thermodynamic Analysis of Pumps

Thermodynamic analysis of Pumps for the system
- An introduction of the function of the device.
Pump is a hydraulic device, which convert the rotational and mechanical energy into kinetic energy in
the form of pressure energy. Pumps apply centrifugal force on the fluid to push towards outlet.
Pumps are widely used in many different industries. For example pump used in the water turbine to pull
the water from bottom to top.
There is various type of pump available for different use here it is given below:
Piston pump
Screw pump
Rotary pump
Diaphragm pump
Gear pump.... Etc.
Centrifugal pump- In simple word, pump is impeller to impel the water from one location to another
with help of centrifugal force. It is very commonly used pump. (Cengel, 2011)
Main components used in pump are the impeller, pump, bearing, seal ring, stuffing box, pump shaft.
Impellers
Impeller is main component of the pump. It contains curved shape vanes and these impellers are vanes
located between the two cover casing and enclosure of the pump. Here is the detail view of the impeller
with casing.
Pump shaft
The main purpose of the shaft is providing transmission of mechanical energy. It is connected between
coupler and motor.
Sliding bearings
It is helpful to maintain the temperature normal, with the help of lubricant oil. In the running condition
the maximum temperature of 85 degree and for general operation 60 degree.

- The thermodynamic cycle of the Pump.
Pump working on the principle of forced by vortex and who says mass of fluid is rotate about the axis as
like in centrifugal force, and then increase the pressure in radial direction and drop out inward direction.
Pressure increment is directly proportional to the squared of the speed. Changing the speed make
changes in the momentum which means more pressure of fluid in outward direction for more
clarification see below image:
In diffuser case the pressure increases and till the exit section of the pump. it is increase the pressure
and velocity of the water also increased.

Total inlet head to the pump =
Total outlet head of the pump =
where and are the velocities in suction and delivery pipes respectively.
Therefore, the total head developed by the pump,
(Cengel, 2011)
- Normal operating conditions that describe the state of the fluid as it moves through the cycle,
As the impeller rotates, the basic operation of the pump is move the fluid from outlet very forcely, for that
fluid enter into the inlet eye and passage from the impeller. Inlet pipe is axial profile and fluid goes to
tangentially with smooth stream along the blade shape, the fluid receive energy while hitting the rotator
part of the impeller and therefore increase the velocity of the fluid and pressure also into the casting. This
kinetic energy or fluid at the outlet section gradually convert into the pressure energy, diffuser blade
mounted on a diffuser ring are used.
The impeller blade having a proper cross section to rotate inside the casing and thereafter towards the
outlet where cross section is getting increase so as per the Bernoullis Principle velocity is reducing and
pressure is going to increase. So fluid velocity is reduced and increases the pressure on the outlet of the