Project Description

What is a cooling tower?

A cooling tower is a heat rejection device that rejects waste heat to the atmosphere through the cooling of a water stream to a lower temperature. Cooling towers may either use the evaporation of water to remove process heat and cool the working fluid to near the wet-bulb air temperature or, in the case of closed circuit dry cooling towers, rely solely on air to cool the working fluid to near the dry-bulb air temperature.

Crossflow water cooling towers

Typically lower initial and long-term cost, mostly due to pump requirements.

Crossflow is a design in which the air flow is directed perpendicular to the water flow (see diagram at left). Air flow enters one or more vertical faces of the cooling tower to meet the fill material. Water flows (perpendicular to the air) through the fill by gravity. The air continues through the fill and thus past the water flow into an open plenum volume. Lastly, a fan forces the air out into the atmosphere.

distribution or hot water basin consisting of a deep pan with holes or nozzles in its bottom is located near the top of a crossflow tower. Gravity distributes the water through the nozzles uniformly across the fill material.

Advantages of the crossflow design:

  • Gravity water distribution allows smaller pumps and maintenance while in use.
  • Non-pressurized spray simplifies variable flow.

Disadvantages of the crossflow design:

  • More prone to freezing than counterflow designs.
  • Variable flow is useless in some conditions.
  • More prone to dirt buildup in the fill than counterflow designs, especially in dusty or sandy areas.

Application

A cooling tower is a heat rejection device that rejects waste heat to the atmosphere through the cooling of a water stream to a lower temperature. Cooling towers may either use the evaporation of water to remove process heat and cool the working fluid to near the wet-bulb air temperature or, in the case of closed circuit dry cooling towers, rely solely on air to cool the working fluid to near the dry-bulb air temperature.