The document is a presentation on cooling towers. It discusses the components, types, and assessment of cooling towers. There are two main types - natural draft towers that use convection and mechanical draft towers that use fans. Mechanical draft towers can be forced draft, induced draft cross flow, or induced draft counter flow. The performance of cooling towers is assessed using parameters like range, approach, and effectiveness. Higher range and lower approach indicate better performance.

1. A
Presentation
On
COOLING TOWERS
Submitted To:
Mr.Rajesh kumar
(Assistant Pro. Mechanical Engineering
Department)
Submitted By:
Ajeet kumar saini
ME 4TH Year
1Copyright Ajeet kumar saini10/2/2018

2. Contents
 Need of Cooling
 Principal of cooling
 Introduction
 Part of cooling tower
 Working of cooling tower
 Type of cooling tower
 Assessment of cooling Towers
 Losses in cooling tower
 Method to improve efficiency of cooling tower
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3. Cooling towers

4. Cooling Tower
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5. Components of cooling tower
 Frame and casing: support exterior enclosures
 Fill: facilitates heat transfer by maximizing water/ air
contact
 Splash fill
 Film fill
 Cold water basin: receives water at bottom of tower.
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6.  Drift eliminators: capture droplets in air stream
 Air inlet: entry point of air
 Louvers: equalize air flow into the fill and retain water
within tower
 Nozzles: spray water to wet the fill
 Fans: deliver air flow in the tower
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7. Types of Cooling Tower
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8. Natural Draft Cooling Towers
 Hot air moves through tower
 Fresh cool air is drawn into the tower from bottom
 No fan required
 Concrete tower<200m
 Used for large heat duties
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10. Mechanical Draft Cooling Towers
Large fan to force air through circulated water
Water falls over fill surfaces: maximum heat transfer
Cooling rate depends on many parameters
Large range of capacities
Can be grouped, e.g. 8-cell tower
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12. Mechanical Draft Cooling Towers
 Three types:
 Forced draft
 Induced draft cross flow
 Induced draft counter flow
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13. Forced Draft Cooling Tower
 Air blown through tower
by centrifugal fan at air
inlet
 Advantages: suited for
high air resistance & fans
are relatively quiet
 Disadvantages:
 Recirculation due to
high air-entry and low
air-exit velocities
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14. Induced Draft Cooling Towers
 Two types:
 Cross flow
 Counter flow
 Advantages: less circulation than forced draft towers
 Disadvantage: fans and motor drive mechanism require
weather- proofinh
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15. Induced Drat Counter Flow CT
 Hot water enters at the top
 Air enters at bottom and exits at top
 Uses force and induced draft fans
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16. Induced Drat Cross Flow CT
 Water enters top and passes over fill
 Air enters on one side or opposite sides
 Induced draft fan draw air across fill
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17. Assessment of cooling Towers
 Range:
 Difference between
cooling water inlet and
outlet temperature:
 Range(0c) = CW inlet
temp – CW outlet temp
 High range = good
performance
(in) to the tower
(out) from the tower
Cold water temperature (out)
Wet bulb temperature
(Ambient)
ApproachRange
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18. Assessment of cooling Towers
 Approach:
 Difference between
cooling tower outlet cold
water temperature and
ambient wet bulb
temperature:
 Approach(0C) = CW
outlet temp – wet bulb
temp
 Low approach = good
performance
(in) to the tower
(out) from the tower
Cold water temperature (out)
Wet bulb temperature
(Ambient)
ApproachRange
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19. Assessment of cooling Towers
 Effectiveness
 Effectiveness in %
 Range /(Range+
Approach)*100
 High effectiveness = good
performance
(in) to the tower
(out) from the tower
Cold water temperature (out)
Wet bulb temperature
(Ambient)
ApproachRange
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20. Calculation Of Efficiency of Cooling
Tower
 Data uses here was taken from AIS Glass
Company at Roorkee
 Let Hot water temperature is denoted as Ti
 Let Cold water temperature is denoted as To
& wet bulb temperature is denoted as Tw
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21. Efficiency of Cooling Tower
Ti=380c
To=320c
Tw= 270c
Therefore efficiency = (38-32)/(38-27)*100
=54.545454 or 55%
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22. Factors that affect the performance of
cooling tower
 Blowdown Losses:
 Evaporation Loss.
 Drift loss:
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