A cooling tower is a specialized heat exchanger in which air and water are brought into direct contact with each other in order to reduce the water’s temperature. As this occurs, a small volume of water is evaporated, reducing the temperature of the water being circulated through the tower.
Cooling tower acts as the cooling medium for the water chiller condenser.
TYPES OF COOLING TOWER
CROSSFLOW TOWER
water vertically flows through the fill media while the air horizontally flows across the falling water.air and water cross paths or flows.
APPLICATION :-HVAC medium cooling capacity chillers
COUNTERFLOW TYPE
-the air vertically flows upwards, counter to the water flow in the fill media. Due to the air flowing vertically, it’s not possible to use the basin’s gravity-flow like in crossflow towers.
APPLICATION :HVAC high capacity water chillers.
FORCED DRAFT
-the air is blown in at the bottom of the tower and exits at the top.
ADVANTAGE:
• Suited for high air resistance due to centrifugal blower fans • Fans are relatively quite
DISADVANTAGE;
Recirculation due to high air-entry and low air-exit velocities, which can be solved by locating towers in plant rooms combined with discharge ducts .
-can be square or rectangular type only
COOLING TOWER CAPACITY
Cooking Tower Capacity
Capacity = 500 x GPM x Temp. diff /12000=Btu/Hr
GPM/Ton = 3.0 GPM/Ton refrigeration
Sample:
Water Chiller Capacity = 100 Tons
Temp in = 95 F/Out=85 F
GPM= 100 x 3 =300 GPM
Capacity = 500 x 300 x 10/12000
Capacity = 125 tons
COOLING TOWER SELECTION
From table select :
Capacity : 300gpm
Select : Model 372-101
Fan Dia.= 96”
L=16’
W=23’-2”
H=12”-10 1/4”