TEAM II

Cooling Tower Analysis

By: Cortez Rankin &

D. Caruthers

Objectives

Components of Cooling Tower Air Outlet Velocities and Flow Rates Air Inlet Velocities and Flow Rates Water Inlet and Outlet Data Comparison of Data @ Different Water Inlet

Flow Rates

Water Cooling Tower

Air Outlet2

Warm Water Inlet

3

Make-Up Water

Air Inlet1 Cool Water

Outlet4

BalancesAssuming Steady State Operation [IN = OUT]

Overall Mass BalanceMAO + M WO = MAI + MWI

Overall Energy Balance

hAO MAO + h WO M WO = h AI M AI+ hWIMWI

AO=Air Outlet AI=Air Inlet

WO=Water Outlet WI=Water Inlet

Portable Cooling Tower

Air Inlet

Air Outlet and Water Inlet

Psychrometric Chart

Air Inlet Data for Water Inlet Flow Rate = 5.1 (l/min)

Velocity = 12.2 m/s Wet Bulb Temp. = 18 °C Dry Bulb Temp. = 25.5 °C Area = 0.038 m2

Relative Humidity = 48% Volumetric Flow Rate= 0.464 m3/s

Air Outlet2

Warm Water Inlet

3

Make-Up Water

Air Inlet1 Cool Water

Outlet4

Air Inlet Data for Water Inlet Flow Rate = 10.1 (l/min)

Velocity = 12.0 m/s Wet Bulb Temp. = 17 °C Dry Bulb Temp. = 25 °C Area = 0.038 m2

Relative Humidity = 45% Volumetric Flow Rate= 0.456 m3/s

Air Outlet2

Warm Water Inlet

3

Make-Up Water

Air Inlet1 Cool Water

Outlet4

Air Inlet Data for Water Inlet Flow Rate = 40.3 (l/min)

Velocity = 8.0 m/s Wet Bulb Temp. = 19 °C Dry Bulb Temp. = 27.5 °C Area = 0.038 m2

Relative Humidity = 45% Volumetric Flow Rate= 0.304 m3/s

Air Outlet2

Warm Water Inlet

3

Make-Up Water

Air Inlet1 Cool Water

Outlet4

Outlet Velocity as a Function of Radiusfor Water Inlet Flow Rate = 5.1 (l/min)

Air Outlet VelocitiesV(r) = -438.81r3 - 111.83r2 + 78.86r + 0.0789

R2 = 0.9876

0

1

2

3

4

5

6

7

8

9

0 0.05 0.1 0.15 0.2 0.25 0.3 0.35

Radius (m)

Vel

oci

ty (

m/s

)

Outlet Velocity as a Function of Radiusfor Water Inlet Flow Rate = 10.1 (l/min)

Air Outlet Velocities

V(r)= -395.28r3 - 118.74r2 + 76.678r + 0.0452

R2 = 0.9955

01234

56789

0 0.1 0.2 0.3 0.4

Radius (m)

Velo

city (m

/s)

Outlet Velocity as a Function of Radiusfor Water Inlet Flow Rate = 40.3 (l/min)

Air Outlet VelocitiesV(r) = -318.78r3 - 32.419r2 + 41.871r + 0.0242

R2 = 0.9965

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

5

0 0.05 0.1 0.15 0.2 0.25 0.3 0.35

Radius (m)

Vel

oci

ty (

m/s

)

Calculate Outlet Air Velocity

2

0 0

2

0 0

)()(

R

R

ave

rdrd

rdrdrV

dA

dArVV

Formulas

Volumetric Flow Rate = (Area)(Velocity)

Mass Flow Rate = (Density)(Volumetric Flow Rate)

Outlet Air for Water Inlet Flow Rate = 5.1 (l/min)

Area = 0.312 m2

Volumetric Flow Rate= 1.7 m3/s Temp. Dry Bulb= 21 °C= Wet Bulb Temp. Enthalpy = 79 kJ/kg Dry Air

Air Outlet2

Warm Water Inlet

3

Make-Up Water

Air Inlet1 Cool Water

Outlet4

Outlet Air for Water Inlet Flow Rate = 10.1 (l/min)

Area = 0.312 m2

Volumetric Flow Rate= 1.6 m3/s Temp. Dry Bulb= 23 °C= Wet Bulb Temp. Enthalpy = 86 kJ/kg Dry Air

Air Outlet2

Warm Water Inlet

3

Make-Up Water

Air Inlet1 Cool Water

Outlet4

Outlet Air for Water Inlet Flow Rate = 40.3 (l/min)

Area = 0.312 m2

Volumetric Flow Rate= 1.0 m3/s Temp. Dry Bulb= 31°C= Wet Bulb Temp. Enthalpy = 123 kJ/kg Dry Air

Air Outlet2

Warm Water Inlet

3

Make-Up Water

Air Inlet1 Cool Water

Outlet4

Water Data for Water Inlet Flow Rate = 5.1 (l/min)

Inlet Temp.= 52.5 oC Outlet Temp.= 27.7 oC Temp. Change= 24.8 oC Mass Flow Rate= 0.085 kg/s Tons of Cooling= 2.5

Water Data for Water Inlet Flow Rate = 10.1 (l/min)

Inlet Temp.= 56.3 oC Outlet Temp.= 31 oC Temp. Change= 25.3 oC Mass Flow Rate= 0.168 kg/s Tons of Cooling= 5.1

Water Data for Water Inlet Flow Rate = 40.3 (l/min)

Inlet Temp.= 52 oC Outlet Temp.= 30.4 oC Temp. Change= 21.6 oC Mass Flow Rate= 0.671 kg/s Tons of Cooling= 17

Admin Tower Schematic

Air InletAll Dimensions Are In cm

Positions of the velocity and temp. measurements

Admin Cooling Tower Front (West) Inlet

Dry Bulb Temp = 18 oC Wet Bulb Temp = 12 oC Area = 4.6 m2

Air Speed = 1.4 m/s Volumetric Flow rate = 6.1 m3/s Density of Area = 1.2 kg/m3

Mass flow rate = 7.3 kg/s

Admin Cooling Tower Front (West) Inlet Team 3

Dry Bulb Temp = 33 oC Wet Bulb Temp = 24.5 oC Area = 4.6 m2

Air Speed = 1.6 m/s Volumetric flow rate = 7.6 m3/s Density of Area = 1.1 kg/m3

Mass flow rate = 8.3 kg/s