Cooling Tower Research Paper

2. Theoretical Background

2.1 Cooling Tower

A cooling tower is a heat rejection device that extracts waste heat to the atmosphere through cooling the water stream to a lower temperature. Cooling towers may work in two different ways: Remove heat and cool the working fluid through the evaporation of water (wet cooling tower), or in the other way, use solely air to cool down the working fluid (dry cooling towers), utilizing convective heat transfer.

There are several important factors that govern the operation of cooling tower: The dry-bulb and wet-bulb temperatures of the air The contact area and time between air and water The inlet temperature of warm water The outlet temperature of the cooled water

Cooling towers are used in different industries such as oil refineries, metal and alloys, food and beverages and pharmaceutical industries. Cooling towers use an environmentally friendly cooling process,

Therefore, their capacities are limited and are usually used in industries with low heat rejection requirements. On the other hand, the field erected type of cooling tower are usually preferred for large scale processing such as power plant, petroleum refineries and steel processing plants. Field erected type cooling towers are lager in size than package type cooling towers.

2.2.2 Classification by air draft

As the name implies, natural draft towers allow for the circulation of air by natural convection. As shown in Figure 2-2, when the air becomes warm and moist, it naturally rises up in the cooler, and as a result, outside air being drawn in. To generate the necessary airflow, natural draft cooling towers require tall stacks to create the required draft. Figure 2-2: Natural draft cooling