In industry, devices for the manufacture of plastics or refrigerators need constant cooling. For these purposes, special equipment is used - a cooling tower. What it is? What is the mechanism of action of this unit? More on this later in the article.
General information
So the cooling tower. What is it? With the help of this equipment it is possible to cool water in large volumes using a directed flow of atmospheric air. Such units are used to lower the temperature using heat exchangers located in various recycling water systems. Cooling towers are widely used in the construction of civilian facilities. For example, as cooling for emergency generators or condensers in refrigeration units.
Classification
In the unit, hot water coming from outside is cooled to the required temperature. It should be remembered when studying how the tower works that this equipment can be of many types. Therefore, before making a choice in favor of one of them, it is necessary to pay attention to the following factors:
- Water consumption.
- Weather conditions.
- Technical calculations.
- The amount of heat removed.
- Location on the site.
- The chemical composition of circulating and additional water.
Cooling towers can also be classified as dry, evaporative and hybrid, depending on the required temperature of the water, the purpose of the chilled liquid, as well as on the method of heat transfer. In accordance with the scope, there are the following types of cooling towers:
- Fan
- Open.
- Evaporative
- Tower.
- Hybrid.
- Natural draft air cooling towers.
- Dry.
It should also be remembered (in cases where a cooling tower is needed) that this equipment, in addition to advantages, also has disadvantages. Consider them in more detail for each species.
Tower cooling towers
Units are the most efficient equipment that is used for cooling water in systems with reverse water supply in industrial enterprises. Inside such an apparatus, air draft is formed naturally by means of an exhaust tower necessary for the circulation of chilled water. The volume of chilled water in such a tower is several times higher than that used by the enterprise. The height of the unit can be about 200 meters, and the total irrigated area is measured at 10,000 m 2 . To cool the water in the tower tower requires minimal costs. It is very easy to operate. The cooling tower can be placed in close proximity to an industrial facility. This unit has only three drawbacks. This, in particular, high inertia, the complexity of the structure and high construction costs.
Evaporative Units
The device of this type of cooling tower provides for the presence of an irrigator, two heat exchangers, a tank for collecting water, a fan, a droplet separator, and collectors of spraying devices. The evaporative cooling tower has several advantages. This includes energy saving, which reaches up to 80%, low material consumption, installation reliability, and minimal repair costs. The life of the evaporative cooling tower is about 30 years. Among the disadvantages, one can list the complexity of cleaning and washing, the growth of water stone on the surface of the pipes.
Fan units
Air supply in such systems is carried out using one or more fans. Due to the movement of the blades, warm air is absorbed through the inlet windows, thereby cooling the water. Fluid flows down the walls into a large tank; vapors of warm air are discharged into the atmosphere using a diffuser and take away the smallest drops. To avoid the loss of a large volume of circulating water, a droplet eliminator should be installed in the upper part of the fan cooling tower. The fan unit allows you to quickly and efficiently cool the water. Such a cooling tower can be used in various climatic and technical ranges. It is easy to operate and repair. The main disadvantage of a fan cooling tower is the high cost of electricity.
Open cooling tower
The principle of operation in such installations is based on natural convection and wind. On all sides, irrigation canals are fenced with blinds that do not allow the removal of water from the pool. Open cooling towers are heavily dependent on wind. Therefore, it is not recommended to build such structures near enterprises that need to maintain a constant temperature of the circulating water. Open cooling towers have a great cooling effect. Because of this, they can be placed on the roofs of buildings or as air conditioning systems. Open cooling towers operate with minimal energy consumption. But then they need high inertia and large areas.
Dry apparatus
In such installations, water is cooled by air using several heat exchangers, axial fans and drain valves. Air filters and pumps are used as auxiliary equipment . The walls of the radiator transfer heat through heat conduction and convection. The water inside the dry cooling tower is cooled using atmospheric air, which is supplied by a low-power fan, which implies energy savings. Dry aggregates are rarely used due to the shallow depth of chilled water. A radiator consisting of aluminum and steel tubes performs the task of a sprinkler. Water is completely isolated from atmospheric air, as it circulates only in a closed circuit. Dry cooling towers are several times more expensive than conventional ones. But they do not increase humidity in the atmosphere and do not pollute it with chemical waste.
Hybrid Aggregates
Such units are designed for dry and wet air cooling. For this, the technology of environmental heat removal to the atmosphere is used. The tower and fans, which are located around the perimeter, cool the water in a dry cooling tower. In such an installation, two or more heat exchange sections or various surfaces are combined. Water cooling in this type of cooling tower occurs between air through the wall and recycled water. Under hot climatic conditions, air intended for cooling water undergoes preliminary humidification in advance. And at low temperatures, dry air is supplied from the atmosphere.