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THE ABSOLUTELY PERFECT,MISTAKE FREE

PRESENTATION ON WETCOOLING TOWERS AND AIR-

CONDITIONING OVERVIEW

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WET COOLING TOWERS

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ANY QUESTIONS?

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The cooling tower is one of themost often overlooked energy

conservation centers and profitmakers that should be recognizedand exploitedRobert Burger(President Burger And

Associates, Inc., Dallas, Texas)

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Overview

Why we use wet cooling towers What they do

Two most common types and how they

compare The advantages and disadvantages of using

them

A review of the important information on air-conditioning in general

Work a practice problem

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What do wet cooling towers

do?

They remove large amounts of wasteheat carried in water

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WHERE?

POWER PLANTS

LARGE AIR

CONDITIONINGSYSTEMS

SOME INDUSTRIES

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Why?

Water used to cool needs to becooled itself so that it can be

reused. Hot water can not simply be

rejected Concerns of thermal pollution

Limited supply of water

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HOW HEAT IS REMOVED

HEAT IS REMOVED BY EVAPORATIVECOOLING

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OLDER APPROACHES TO

COOLING WASTE WATER

COOLING POND WATER IS DUMPED INTO A LARGE POND

HUGE AMOUNT OF WATER NEEDED

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COOLING POND

Hot water out

Cold water in

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THE SPRAY POND

SPRAY POND WATER IS SIMPLY SPRAYED IN THE AIR

OVER THE POND AND IS COOLED

1/20th THE AREA OF A COOLING POND ISNEEDED

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SPRAY POND

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TWO TYPES OF COOLING

TOWERS

INDUCED DRAFT COUNTERFLOWCOOLING TOWER

NATURAL DRAFT COOLING TOWER

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INDUCED DRAFT COUNTERFLOW

COOLING TOWER

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INDUCED

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INDUCED DRAFT COUNTERFLOW

COOLING TOWER

INDUCED

DRAFT

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NATURAL DRAFT COOLING

TOWER

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Natural draft cooling tower

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Advantages

BOTH COOL USING 1/25th

TO 1/50th

THE AREA OF A SPRAY POND

VERY EFFECTIVE AND EFFICIENT WAYOF COOLING WASTE HEAT

LITTLE POLLUTION

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DISADVANTAGES

Dont look pretty Lose water due to drift

Steam escaping looks like pollution Cause Legionnaires Disease

Legionnaires disease is a type ofpneumonia affecting the lungs

Must be specially cleaned

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Eliminating Drift

As much drift aspossible must beeliminated to reduce

losses and preventspread oflegionnaires disease

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Drift eliminator

The water isremoved fromthe air by the

S-shape of thedrift eliminator

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Side view

The slightangle

increases driftelimination

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Head to Head Induced Noisy

Expensive torun

Cheaper tobuild

Natural Quiet

Cheap to run

Expensive tobuild

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AIR-CONDITIONING THINGS

YOU SHOULD KNOW

THE PSYCHROMETRIC CHART FIND TWO PROPERTIES OF AIR ON THE

CHART AND YOU CAN FIND ALL OF THEOTHER PROPERTIES

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Enthalpy change

hdry air=Cp

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Dry bulb temperature

Tdb The ordinary temperature of air

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Wet-bulb Temperature

TwbThe temperature withregard to the moisture in

the air

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Dew Point temperature

TdpThe temperature of air atwhich water will begin to

condense

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Specific Humidity = mv/maThe mass of water vaporpresent in 1 unit mass ofdry air

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Relative Humidity

= mv/mgThe ratio of the amount ofwater air can hold to what

it is holding

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PROBLEM 13-25

After a long walk in the 8 C outdoors, aperson wearing glasses enters a roomat 25 C and 40 percent relative

humidity. Determine if the glasses willfog.

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CONCLUSION

WET COOLING TOWERS DISPOSE OFWASTE HEAT TO THE AIR

THE PSYCHROMETRIC CHART RULES

SO DOES AIR-CONDITIONING

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ANY QUESTIONS?