Cooling Tower Action
Water cooling towers are used in commercial and residential applications to cool the water used in HVAC and refrigeration systems. Large volumes of water are used to keep condensers at right temperatures for a cooling effect. Tap water is used in these systems and instead of sending the water into a sewer systems it is recycled in water cooling towers to lessen the cost of using municipal water supplies.
Water is recirculated through a compressor’s outer shell after undergoing a cooling and replenishment cycle inside the tower. Inside the tower, a water spray design spreads the water droplets. Those droplets come into contact with an airstream and become cooler. A pump circulates the cooled water back through the refrigerant condenser. Cooling towers vary in size. They may be roof-top units or very large units that rise to the height of 130ft.
The realization of a water cooling tower originated in the 19th century when it was necessary to cool water for steam engines. Cooling the water was seen to have an impact on fuel consumption as the cooled water reduced back pressure. Moving into the 20th century, cooling ponds were used because municipal water supplies were just beginning to grow. Water cooling towers then began to be enhanced by the Dutch and industrial engineers in the United Kingdom.
HVAC and Cooling Tower Applications
Water cooled towers are more energy efficient than air cooled chillers because heat can be rejected at wet bulb temperatures. Air cooled chillers must reject heat at dry bulb temperatures. The cooling of water is required in petrochemical plants, oil refineries, chemical plants, power stations, military bases, and hospital situations. Nuclear power plants and coal fired plants use water cooling towers also.
Water Cooling Towers and Airflow
This cooling method relies on the use of a continuous flow of air that serves to cool water. This flow of air is created using one of five different methods. A mechanical draught system uses electrically powered fans to move the air. The natural draft method uses the fact that moist and warm air will rise up through the tower creating a natural draft and evaporation. The induced draught method calls for a fan to be placed at the top of the tower which pulls the warmer air up and out. A forced draught method involves the placement of a fan at the intake portion of the tower. This fan forces air into the tower pushing air up. The fan assisted natural draught method is a hybrid method that looks like a natural draft but the fan still propels air up and out of the tower.