In industry, devices for the manufacture of plastics or refrigeration apparatus need constant cooling. For these purposes, special equipment is used - the cooling tower. What it is? What is the mechanism of action of this unit? About this later in the article.
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 reduce the temperature with the help of heat exchangers located in various systems of circulating water supply. Cooling towers are widely used in the construction of civilian facilities. For example, as cooling for emergency power generators or condensers in refrigeration plants.
In the unit, the hot water coming from outside is cooled to the required temperature. It should be remembered, studying how the cooling tower works, that this equipment is of many kinds.
Therefore, before making a choice in favor of one of them, it is necessary to pay attention to the following factors:
Cooling towers can also be classified into dry, evaporation and hybrid, depending on the required water temperature, the intended use of the cooled liquid, and also the heat transfer method.
According to the application, the following types of cooling towers exist:
It should also be remembered (in cases where a cooling tower is needed) that this equipment, apart from its advantages, has drawbacks. Let us consider them in detail for each species.
Aggregates are the most efficient equipment that is used to cool water in systems with recycled water supply in industrial plants. Inside such an apparatus, the draft of air is formed naturally by means of an exhaust tower, which is necessary for the circulation of chilled water. The volume of chilled water in such a cooling 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 m2. To cool the water in the cooling tower, the minimum costs are required. 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, complexity of construction and large construction costs.
The structure of the cooling tower of this type provides for the presence of a sprinkler, two heat exchangers, a water collection tank, a fan, a drop separator, and collectors of sprinklers. The evaporative cooling tower has several advantages. This is energy saving, which reaches 80%, a small consumption of materials, reliability of installation, minimum costs for repairs. The operation life of the evaporative cooling tower is about 30 years. Of the shortcomings can be listed the complexity of cleaning and washing, the buildup of water stone on the surface of the pipes.
Air supply in such systems is carried out with the help of one or several fans. Due to the motion of the blades, warm air is sucked through the entrance windows, thereby cooling the water. The liquid flows down the walls into a large reservoir; A pair of warm air is discharged into the atmosphere by means of a diffuser and carries with it the tiniest drops. To avoid the loss of a large volume of circulating water, a drip trap must be installed at the top of the cooling tower. The fan allows quick and high-quality cooling of the water. Such a cooling tower can be used in various climatic and technical ranges. It is easy to operate and repair. The main drawback of a cooling tower is the high cost of electricity.
The principle of operation in such installations is based on natural convection and wind. On all sides irrigation canals are fenced with blinds, which do not allow the removal of water from the pool. Open cooling towers are heavily dependent on the wind. Therefore, it is not recommended to build such structures near enterprises that need to maintain a constant temperature of circulating water. Open cooling towers have a large cooling effect. Because of this, they can be placed on the roofs of buildings or as air conditioning systems. Open cooling towers work with minimal energy costs. But they need high inertia and large areas.
In such installations, the water is cooled by air using several heat exchangers, axial fans and drain valves. As an auxiliary equipment, air filters and pumps are used. The walls of the radiator transmit heat due to heat conduction and convection. The water inside the dry cooling tower is cooled by atmospheric air, which is supplied by a low-power fan, which involves saving energy. Dry aggregates are rarely used because of the shallow depth of chilled water. The radiator, consisting of aluminum and steel pipes, fulfills the task of the sprinkler. The water is completely isolated from the atmospheric air, as it circulates only through a closed circuit. Dry cooling towers are several times more expensive than conventional cooling towers. But they do not increase the humidity in the atmosphere and do not pollute it with chemical waste.
Such units are designed for dry and wet air cooling. For this, the technology of environmental heat removal into 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 different surfaces are combined. Cooling of water in this type of cooling tower occurs between air through the wall and recycled water. In hot climates, the air intended for cooling water pre-humidifies beforehand. And at low temperatures dry air is supplied from the atmosphere. -