How Cooling Tower Works
Cooling tower is the cost effective heat removal solution used for removing large heat load.
Cooling Tower Basics
Cooling tower cools water based on diffusion principle. When water particles comes in contact with moving air, some amount of the water evaporates and while evaporating it takes latent heat from rest of the water of the particle. This process reduces temperature of the whole particle much lower than air temperature (more accurately air dry bulb temperature). This is the reason cooling tower can produce more cooling effect than radiator. Wet bulb temperature plays important role in cooling tower design and selection.
Types of Cooling Tower
- Cross Flow: In these types of cooling tower, flow of air and flow of water crosses each other while exchanging heat. Typical representation of such cooling tower should look like below:
- Counter flow: In counter flow cooling towers, heat exchange between water and air occurs while they pass each other in opposite direction. Below figure explains a typical counter flow cooling tower:
- Natural draft cooling tower: Natural draft cooling tower don’t use a fan to suck air from surroundings, it works on natural flow of air. Because of height difference (i.e. pressure difference) air naturally flow from bottom to top of the cooling tower, which creates natural flow of air. Natural draft cooling towers are generally used in nuclear power plant.
- Force draft cooling tower: Force draft cooling tower uses fan to create positive pressure difference and to generate air flow.