The document discusses different components of a steam condenser system including condensers, cooling towers, and cooling ponds. It describes the functions of condensers in reducing turbine exhaust pressure and reusing condensed steam. Surface condensers are preferred over jet condensers as they allow for pure condensate reuse. Cooling can be achieved through natural or mechanical draft cooling towers, induced or forced draft designs, and through cooling ponds with different arrangements to maximize heat transfer from water to air.

1. STEAM
CONDENSER
COOLING
TOWERS &
COOLING PONDS1
prepared by :- Raxit V. Varmora

2. Prepared By :-
 Varmora Raxit V.
2prepared by :- Raxit V. Varmora

3. STEAM CONDENSER
Definition:
 Condenser is a device in which steam is condensed to water
at a pressure less than atmosphere.
 Condensation can be done by removing heat from exhaust
steam using circulating cooling water.
 During condensation, the working substance changes its
phase from vapor to liquid and rejects latent heat.
 The exhaust pressure in the condenser is maintained nearly
7 to 8 kpa which corresponds to condensate temperature of
nearly 313 kelvin.
3prepared by :- Raxit V. Varmora

4. FUNCTIONS OF
CONDENSER:
 To reduce the turbine exhaust pressure so as to increase the
specific output and hence increase the plant efficiency and
decrease the specific steam consumption.
 To condense the exhaust steam from the turbine and reuse it as
pure feed water in the boiler. Thus only make up water is
required to compensate loss of water
 Enables removal of air and other non condensable gases from
steam. Hence improved heat transfer.
4prepared by :- Raxit V. Varmora

5. ELEMENTS OF
CONDENSING PLANT:
Condenser
 Air Extraction Pump
 Condensate Extraction Pump
 Cooling Water Circulating Pump
 Hot Well
 Cooling Tower
 Make up Water Pump
 Boiler Feed Pump
5prepared by :- Raxit V. Varmora

6. 6
prepared by :- Raxit V. Varmora

7. It increases the work output per kg of steam supplied
to the power plant. It also reduces the specific steam
consumption, therefore reduces the size of power plant
of given capacity.
It improves the thermal efficiency of the power plant.
It affects the saving in cost of water to be supplied to
the boiler since the condensate is returned to the boiler.
Cost of water softening plant is also reduced since
pure feed water is available for the boiler.
7
Advantage of a
Condenser
prepared by :- Raxit V. Varmora

8. CLASSIFICATION OF
CONDENSERS:
Jet Condensers or mixing type
1. Low Level Parallel Flow Jet Condenser
2. Low Level Counter Flow Jet Condenser
3. High Level Jet Condenser
4. Ejector Jet Condenser
Surface Condensers or Non-mixing type
1. Down Flow
2. Central Flow
3. Inverted Flow
4. Evaporative type
5. Regenerative type 8prepared by :- Raxit V. Varmora

9. JET CONDENSERS
In jet condensers exhaust steam and cooling water come in
direct contact and mix up together. Thus, the final
temperature of condensate and cooling water leaving the
condenser is same.
Such condensers are normally used for small power units.
It can be used when cooling water is cheaply and easily
available.
These condensers are not usually employed since the
Condensate collected can not be reused in boiler, because
it contains impurities like dust, oil, metal particles etc in
the condensate.
9prepared by :- Raxit V. Varmora

10. LOW LEVEL PARALLEL
FLOW JET CONDENSER
Exhaust steam and cooling
water both flow in the
same direction.
Wet air pump is used to
extract the mixture of
condensate, air & coolant.
This limits the vacuum
created in the condenser
up to 600 mm of Hg.
10prepared by :- Raxit V. Varmora

11. LOW LEVEL COUNTER
FLOW JET CONDENSER:
 The cooling water is supplied
from the top of the condenser and
steam from side of the condenser.
 The water flows in downward
direction through a series of
perforated trays. Steam gets
condensed while it comes in
contact with the falling water.
 The air pump always maintains
the required vacuum in the
condenser and induces the
cooling water to be lifted into the
condenser up to a height of 5.5m.
 The excess amounts of
condensate from hot well flows
into the cooling pond by an
overflow pipe.
11prepared by :- Raxit V. Varmora

12. HIGH LEVEL JET
CONDENSER OR
BAROMETRIC JET
CONDENSER Condenser shell is installed at
height greater than that of
atmospheric pressure in water
column i.e. 10.33 m.
 A tall pipe more than 10.33m
length is attached to the bottom
of the condenser. This allows the
condensate and coolant to be
discharged from condenser under
the gravity action; hence a
condensate extraction pump is
not required.
 The water from the hot well will
not be able to rise into the
condenser and flood the turbine
due to vacuum pr. Maintained in
condenser. 12prepared by :- Raxit V. Varmora

13. EJECTOR CONDENSER:
In this cooling water enters from the
top of the condenser at least under a
head of 6m of water pressure with
the help of a centrifugal pump and
then it passes over a series of
convergent nozzles and finally it
leaves through a convergent
divergent nozzle.
The non return valve helps in
preventing the rush of water from
hot well to the engine in case the
cooling water supply fails.
Momentum of flowing water is
used to remove the mixture of
condensate & coolant from
condenser without the use of any
extraction pump. 13prepared by :- Raxit V. Varmora

14. ADVANTAGES &
DISADVANTAGES OF JET
CONDENSERS:
Advantages:
 Simple in design & cheaper.
 Less floor area is required.
Disadvantages:
 Condensate is not pure hence can not be reused.
 Low vacuum efficiency.
14prepared by :- Raxit V. Varmora

15. SURFACE CONDENSERS
 In surface condenser, the exhaust steam and cooling water
do not come in physical contact, rather they are separated
by heat transfer wall. Hence condensate remains pure &
can be reused.
15prepared by :- Raxit V. Varmora

16. DOWN FLOW SURFACE
CONDENSER:
 Exhaust steam enters the top
of condenser shell & flows
downward over water tubes.
 Water tubes are double
passed. The cold water flows
in lower side first & then in
upper side in the reverse
direction, which enables the
maximum heat transfer.
16prepared by :- Raxit V. Varmora

17. CENTRAL FLOW SURFACE
CONDENSER
 The steam flows radially inward
 The condensate is collected
at the bottom of the shell from
where it is taken out by the
condensate extraction pump.
 The steam gets access to the
entire periphery of tubes, and
thus a large surface area for the
hear transfer is available as
compared to the down flow.
17prepared by :- Raxit V. Varmora

18. INVERTED FLOW
CONDENSER:
 The steam enters the bottom of the shell and air extraction pump
connected at the top.
 Steam flows upward first and subsequently, returns to the
bottom of the condenser.
 The condensate extraction pump is connected at the bottom of
the shell to extract the condensate.
18prepared by :- Raxit V. Varmora

19. EVAPORATIVE CONDENSER:
 The evaporation of some
cooling water provides the
cooling effect, thereby
steam condenses.
 Steam to be condensed is
passed through grilled tubes
& cooling water is sprayed
over outer surface of tubes.
 The evaporative condensers
are most suitable for small
plants, where supply of cold
water is limited. 19prepared by :- Raxit V. Varmora

20. ADVANTAGES &
DISADVANTAGES OF
SURFACE CONDENSERS:Advantages:
 High vacuum efficiency.
 Pure condensate.
 Low quality cooling water can be used.
 It allows the expansion of steam through a higher pressure ratio.
Disadvantages:
 Large amount of water is required.
 Construction is complicated.
 Costly maintenance and skilled workers.
 Large floor area.
20prepared by :- Raxit V. Varmora

21. COMPARISON OF JET &
SURFACE CONDENSERS:
Jet Condensers
1) Cooling water and steam are mixed up
2) Requires small floor space
3) The condensate cannot be used as feed water
to boiler unless it is free from impurities
4) More power is required for air pump
5) Less power is required for water pump
6) Requires less quantity of cooling water
7) The condensing plant is simple
8) Less suitable for high capacity plants due to
low vacuum efficiency
Surface Condensers
1) Cooling water & steam aren’t mixed up
2) Requires large floor space
3) The condensate can be used as feed water to
boiler as it is not mixed with cooling water
4) Less power is required for air pump
5) More power is required for water pump
6) Requires large quantity of cooling water
7) The condensing plant is complicated
8) More suitable for high capacity plants as
vacuum efficiency is high
21prepared by :- Raxit V. Varmora

22. VACUUM CREATION IN
CONDENSER:
• When the steam condenses in a closed vessel, the vapour phase of
working substance changes to liquid phase, and thus its specific
volume reduces to more than one thousand times.
• Due to change in specific volume, the absolute pressure in the
condenser falls below atmospheric pressure and a high vacuum is
created.
• This minimum pressure that can be attained depends on the
temperature of condensate and air present in the condenser.
The absolute pressure = Atmospheric pressure – Vacuum Gauge
in the condenser Pressure
22prepared by :- Raxit V. Varmora

23. COOLING TOWERS
Types of cooling tower
A. Natural draught-cooling towers
B. Mechanical cooling towers
1. Forced draught cooling towers
2. Induced draught cooling towers
23prepared by :- Raxit V. Varmora

24. NATURAL DRAUGHT-
COOLING TOWERS
 Natural draft cooling towers
operate on the stack effect
which causes the hot air in the
tower to rise (natural draft).
 Wet natural draft cooling
towers are used mainly for
electrical energy industry,
but can be used for other
industrial objects.
 Such towers allow the cooling
of high water volumes and are
designed both from concrete
and metal structures. 24prepared by :- Raxit V. Varmora

25. Advantages :
• Power saving (no power consumption to induce air flow-
no fan)
• Environmentally friendly
• No mechanical noise (no fan)
• Safety of operation
• No recirculation as the plume is rejected at high level
• Limited plot area
• Limited maintenance
• Payback period between 8 and 16 years depending on
several factors
Disadvantages :
• Higher investment costs
• Large overall dimensions that could cause difficulties with
area aesthetics and requirement of large areas for tower
installation 25prepared by :- Raxit V. Varmora

26. MECHANICAL DRAFT
COOLING TOWERS
 The mechanical draft cooling
towers are very much similar
to that of the natural draft
cooling towers. As the name
indicates, air is circulated
inside the tower
mechanically instead of
natural circulation. Propeller
fans or centrifugal fans may
be used.
26prepared by :- Raxit V. Varmora

27. Advantages
 For the same capacity used, the mechanical draft cooling towers are
much smaller than the natural draft cooling towers. This is because of
the increase in cooling capacity due to increase in volume of the air
being forced out by fan.
 Capacity control is possible in mechanical draft cooling tower. By
controlling the speed of the fan, the volume of air can be controlled,
which in turn controls the capacity.
 As they do not depend upon the atmospheric air, the mechanical draft
cooling towers shall be located even inside the building.
Disadvantages
 More power is required to run the system,
 Increased running cost due to increase in maintenance of the fans,
motors and its associated controls.
27prepared by :- Raxit V. Varmora

28. INDUCED DRAUGHT
(COUNTER FLOW)
COOLING TOWER A mechanical draft tower
with a fan at the discharge (at
the top) which pulls air up
through the tower.
 The fan induces hot moist air
out the discharge.
 This produces low entering
and high exiting air
velocities, reducing the
possibility of recirculation in
which discharged air flows
back into the air intake.
 This fan/fin arrangement is
also known as draw-through. 28prepared by :- Raxit V. Varmora

29. INDUCED DRAUGHT
(CROSS-FLOW) COOLING
TOWER In cross-flow cooling tower
systems the water vertically
flows through the fill media
while the air horizontally flows
across the falling water. That's
why they call it "cross-flow"
because the air and water cross
paths or flows.
 Because of the crossing of
flows, the air doesn't need to
pass through the distribution
system. This permits the use of
hot water flow via gravity and
distribution basins on the top of
the tower right above the fill
media.
29prepared by :- Raxit V. Varmora

30. Principle Natural draught cooling
tower
Forced draught
cooling tower
Size and shape It may be 125 m high and 100 m
in diameter and has hyperbolic
shape.
It may be 15 m high and
thousands of meters in
length and has long
rectangle box shape.
Initial cost High Half of natural tower
draught cooling tower.
Operating cost Less High
Maintenance cost Low High
Water loss Less More
Life More Less 30prepared by :- Raxit V. Varmora

31. COOLING PONDS
A cooling pond is a man-made body of water primarily formed for the
purpose of supplying cooling water to a nearby power plant.
 Cooling ponds are used where sufficient land is available, as an
alternative to cooling towers.
 The cooling pond is one of the simple method of cooling the condenser
water.
 This method is less efficient than cooling water.
 Types of the cooling ponds:
1. Natural and directed flow cooling pond.
2. Single deck and double deck cooling pond.
3. Spray pond with louvre fence 31prepared by :- Raxit V. Varmora

32. NATURAL FLOW
COOLING POND
 Figure shows a non-
directed flow natural
cooling pond. In natural
 flow system, water coming
out from the condenser is
just allowed to flow into the
pond.
 This system is rarely used
now-a-days.
32prepared by :- Raxit V. Varmora

33. DIRECTED FLOW
COOLING POND
 In directed flow system, the hot
water coming out of condenser
enters the middle
 Channel as shown in fig and on
reaching the far end divides into
two currents, being
 Directed by the baffle walls so as
to traverse the pond several times
before uniting at the
 Intake point. The water gets more
time and passes over a more
surface, so the cooling
 Achieved is very effective.
33prepared by :- Raxit V. Varmora

34. SINGLE DECK SPRAY
POND
 In a single deck arranged the
same elevation as shown in
Fig.
 Its effective cooling effect is
less than double deck system.
In this system warm water
 received from the condenser is
sprayed through the nozzles
over a pond of large area and
 cooling effect is lost by
evaporation and windage.
34prepared by :- Raxit V. Varmora

35. DOUBLE DECK SPRAY
POND
 In this system, spray
nozzles are arranged at
different elevations as
 shown in Fig. Its cooling
effect is more than single
deck system as water
comes in contact
 with air at lower
temperature.
35prepared by :- Raxit V. Varmora

36. SPRAY POND WITH
LOUVRE FENCE
 In case of open pond the
draft losses will be more if
the wind velocity is high.
This can be avoided by
providing Louvre fence as
shown in figure.
36prepared by :- Raxit V. Varmora

37. Advantages of cooling ponds:
 Its initial cost is less.
 Simple in design and arrangement.
Disadvantages of cooing ponds:
 It requires large area for cooling.
 More amount of loss of water due to evaporation and
windage run.
 Low cooling efficiency.
 There is no control over the temperature of cooled water.
37prepared by :- Raxit V. Varmora

38. 38prepared by :- Raxit V. Varmora