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INTRODUCTON
PRIME MOVERS DEFINATION
 Prime movers is a device which use the
energy from natural sources and convert in to
mechanical works.
 Before the development of machine man had
to depend on his own physical strength and
on animal, mainly horse.
 So when was the mechanical system was
invented at that time unit of power is horse
power.
 Technically, it is a group of machines that
transform energy from thermal, electrical, or
pressure into mechanical form for use in
different sources for some mechanical work.
Engines and turbines are examples.
Sources of energy used by Prime
movers.
 Burning of fuels:



It is the most important topics of energy. heat
energy is librated when fuel is burnt.
Different fuels have different calorific value
based on on heat is given out.
The heat energy converted in to mechanical
work by using heat energy.
 River water:
River water is another useful and widely used
another sources.
Water potential energy convert in to the
kinetic energy when it reaches the prime
movers.
River water is also used to generate the
steam in the boiler and its used in the steam
turbine.
 Atoms:
Using atoms as a source of energy is recent
development. It is also widely use energy
source. heat energy produce by fission of the
atoms.
 Wind and solar energy:
It is the renewable energy sources of energy.
this is the freely available energy sources.
Sources of energy to run prime
movers
Sources of energy
Non Thermal
Thermal
water
fuel
Nuclear
External combustion engine
Reciprocating
steam engine
Geothermal
Tidal power
Bio-gas
wind
Solar energy
Internal combustion engine
Reciprocating I.C
engine
Stem turbine Closed cycle
gas turbine
Open cycle
gas turbine
Definitions
 Force :
A body of mass m subject to a force F undergoes an
acceleration a that has the same direction as the
force and a magnitude that is directly proportional to
the force
i.e., F = ma.
 Weight:
It is the force exerted by gravity
w = m x g (N)
Weight of an object is not constant. It depends on the
gravitational force
 Mass : Mass is the quantity of matter. It depending
force acting on it. Mass of the body is same weather
the body is on the moon or the earth.
 Pressure: Pressure is the ratio of force to the surface
area over which it is exerted.
Pressure :
Force (n)

2
Area (mm )
n
1 pascal  1
mm 2
 Breaker power : Power delivered by the
engine is break power.
 Energy : It is defined as the capacity of doing
work.
Energy conservation
 Energy cannot be destroyed or created it can
change from its State. This conversion may
be completed or partial
 High grade energy:
Energy that can completely converted in to
the work.
 Low grade energy:
energy of which only certain portion can be
converted in to the work.
 Specific heat : energy is required to rise the
temperature of unit mass of a substance by one degree
is know as its specific heat.
 Which is denoted by (c)
Q  m  C  T
Q( KJ )
C 
m( Kg )  T ( K )
 Unit of specific heat is kj / kg k
 Melting point:
The point it where the solid converted in to the liquid when heat
is added.
 Boiling point:
The point it where the liquid converted in to the vapour when
heat is added.
 Critical point:
It is the temperature above which only one phase is existing. i.e
vapour
 Tripple point
It is the temperature at which all the three phases solid, liquid
and vapour are in equilibrium. Below this point only two phase
are existing solid and vapour.
solid is directly converted into the vapour.
This process called sublimation
Types of systems
 Open system
a system where matter or energy can flow
into and/or out of the system.
Heat
mass
 Closed system :
where energy can enter or leave but matter may not.
i.e pressure cooker
 Isolated system :
In these system energy and mass can not across the
boundary.
i.e thermos flask
 Enthalpy : It is the combination of the (u+pv)
it is defined enthalpy and is given symbol.
it is denote by (H).
H= u + pv
Efficiencies
 Brake power of an engine (b.p):
It is the power available for work at the output shaft of
the engine.
 Indicated power (i.p) :
It is the power developed in its engine cylinder
 Friction power : i.p = b.p + Friction power
 Mechanical efficiency :
braekpower
 mech
indicatedpower
Steady flow energy equation (SFEE)
Enter
P1 v1
w
U1 c1
p1v1
EXIT
z1
P2 V2
entery
q
Datum line
z2
U2 C2
 P1 and p2 – Pressure at the entry and exit.
 V1 and v2 – volumes at the enter and exit m3 /
kg
 U1 and u2 – internal energy at the entry and
exit kj/kg.
 C1 an c2 – velocity at the entry and exit m/s
 Potential energy : This is because of the height of the
fluid from the datum.
 P.E = z kj/kg
 Kinematics energy : it is the energy because of the
motion of the fluid.
 K.E =
1 2
c kj / kg
2 gc
 Internal energy : Internal Energy is the
energy stored in a system at the molecular
Level.
 Which is denoted by the (u) and the unit is
kj/kg
 Flow and displacement work :
 Flow work at the entry = p1v1
 Flow work at exit = p2v2
 Heat received by the system = q kj/kg
 External work done by the system = w kj/kg.
2
2
c
c
z1  u1  p1v1  1  q  z2  u2  p2v2  2  w
2 gc
2 gc
 By the law of conservation of energy we have
 Total energy entering at the system = Total energy
leaving the system
2
2
c1
c2
z1  u1  p1v1 
 q  z2  u2  p2v2 
w
2 gc
2 gc
 First Law of Thermodynamics :
 The first law of thermodynamics is often
called the Law of Conservation of Energy.
This law suggests that energy can be
transferred from one system to another in
many forms. Also, it can not be created or
destroyed.
 Zeroth law of thermodynamics:
If two bodies are thermal equilibrium with
third body and they are also thermal
equilibrium with each other .
 Second law of thermodynamics:
Two statement for 2nd law of
thermodynamics
1. Kelvin Plank Statement.
2. Clausius statement.
 Kelvin Plank Statement :
it is impossible for any device that operate
on a cycle to receive heat from a single
source and produce a net amount of work.
 Clausius statement :
It is impossible to construct a device that
operates in a cycle and produce no effect
other than the transfer of heat a lower temp.
body to a higher temp. body.