introduction for condenser & cooling tower & their type

1. Condensers
&
Cooling Towers
by
Mr. S. R. Khandagale
1

2. Condenser
It is a device which condenses working fluid with the
help of cooling media (another circulating fluid)
• IF cooling media is air  Air cooled condenser
mostly used in refrigeration or mobile equipment
• IF cooling media is water  water cooled condenser
mostly used in stationary plants
2

3. Steam condenser
It is condenser which is used to condense steam
Steam condensers are mostly water cooled
i.e. in steam condenser
working fluid steam
cooling media water
• Functions
1. Maintain condensing pressure below atmospheric
 for improving efficiency
2. to supply hot(?) and pure water to cycle again
3

4. Elements in condensing plant
• (
4

5. Classification
Depending upon contact of working fluid and
cooling media
A. Jet condenser  Direct Contact
B. Surface Condenser  Indirect contact
5

6. Jet Condenser
a. Low level jet condenser
Cooling water required to lift up to 5.5 m
i. Counter flow
Cooling media & steam flow in opposite direction
ii. Parallel Flow
Cooling media & steam flow in same direction
b. High level jet condenser
Cooling water required to lift above 10.33 m
c. Ejector jet condenser 6

7. 1. Low level Counter flow jet steam condenser
Condensate extraction pump  Required
Cooling water pump Not required 7

8. 2. High level counter flow jet condenser
Cooling water pump  required
Condensate extraction pump  not required
8

9. Ejector Condenser
1. Non return valve
2. Convergent Nozzle:
It reduces pressure of cooling water
3. Convergent divergent nozzle
It increases pressure on mix of cooling
water and steam upto atmospheric
This system is simple, reliable and cheap
9

10. B. Surface Condenser
1. Shell and tube surface condenser
a. Single Pass
b. Double Pass
2. Central flow surface condenser
3. Down flow surface condenser
4. Inverted flow surface condenser
5. Evaporative condenser
10

11. Shell and tube Surface Condenser
Cooling water flows
through tubes
Steam flows through
shell
As cooling water
passes 2 times it is
double pass condenser
11

12. Down Flow Surface Condenser
Steam extraction pump at down
Baffles guides the steam flow .
Also called cross flow heat
exchanger as steam & water fow
right angles to each other
12

13. CENTRAL FLOW SURFACE CONDENSER
Air extraction pump is
located at the center of the
condenser tubes.
Provides the better contact
of steam
13

14. EVAPORATIVE CONDENSER (Cooling water evaporates)
Cooling water evaporates
 Steam through pipes
 Cooling water sprinkles
through nozzles
Fins are provided to
a)Act as obstruction to
flow of water drops
b) increase heat transfer
surface area
14

15. JET CONDENSER SURFACE CONDENSER
Direct contact Indirect contact
Condensation due to mixing Condensation due to heat transfer by
conduction and convection
Maintenance cost is low Maintenance cost is high.
Less Vacuum created More Vacuum created
Small floor space required Large floor space required
Condensate can not be directly used as
feed water
Condensate can be directly used as feed
water
Less power for pumping More power for pumping
Less quantity of cooling water required Large quantity of cooling water required
Suitable for low capacity plants Suitable for large capacity plants
15

16. Cooling Tower
• Cooling towers are commonly used to remove
excess heat that is generated & represent a
relatively inexpensive and dependable means of
removing low-grade heat from cooling water
Working fluid cooling water
Cooling media  air
Some of cooling water evaporates leading to cooling
effect
16

17. Cooling tower types
• Natural draft
Air circulation due to density differences
• Mechanical or forced or induced draft
Air circulation due to fans
17

18. Natural Draft Cooling Towers.
Flow is due to sprays or a differential in air
density
air velocities for the vertical spray tower are
relatively low
normally used when operating temperatures
are not critical
to the system.
staged pumping systems are normally
recommended to reduce energy use in
periods of reduced load and
ambient conditions.
18

19. Mechanical / forced /induced draft cooling
towers
Air Circulation is due to fans
Increased air flow improves
evaporation rate
centrifugal fan  Incoming air
axial air  Outgoing air
Higher capacity
19

20. Factors governing operation of Cooling
tower
• The dry-bulb and wet-bulb temperatures of the air
• The temperature of warm water
• The area of contact between air and hot water
• The contact time between the air and the water
• The air pressure drop
• The desired temperature of the cooled water 20