11.08.2020

Water cooling towers

Why and on what principle does the water cooling tower work

Photo and video

As it turned out, approaching the territory of the Chernobyl nuclear power plant, people very often confuse a special tower for cooling water from the reactor with the reactor itself. The first thing that our tourists meet on their way towards the Chernobyl nuclear power plant is the unfinished so-called third stage of the Chernobyl nuclear power plant, in simple human terms - the fifth and sixth unfinished reactors. Reactors and auxiliary elements for them. These auxiliary elements will be discussed in today's article.


Cooling tower. It is also a tower for cooling hot water from reactors. In order to tell you, our dear readers, about the origin of these towers on the territory of the station, you need to go back a little back in the history of the construction of the Chernobyl nuclear power plant itself. Surely many have heard that for cooling hot water from reactors, there was, as a rule, a huge reservoir near a nuclear power plant - a cooling pond. So it was with the Chernobyl nuclear power plant.
During the construction of the first stage (the first and second power units), the cooling pond occupied an area of ​​only 12 square kilometers. A little later, after the construction of the second stage (the third and fourth power units), the area of ​​the cooling pond increased to almost 23 square kilometers. But at the beginning of the construction of the third stage of the station, it was decided not to expand the pond anymore due to the fact that there was simply no such physical opportunity. This was hampered by the city of Chernobyl, located south of the pond. For this reason, the decision was made in favor of those same cooling towers.


What exactly is a cooling tower? The cooling tower is a special concrete structure in the form of a tower designed to cool huge amounts of hot water through a directed air flow.


The high tower creates the very air draft that is necessary for efficient cooling of the circulating hot water. Exhaust towers are used to create natural draft due to the difference in specific gravity of the air entering the cooling tower and the heated air leaving the cooling tower. Under the sprinkler, there is a drainage tank of the pool type. Water is supplied to the water distribution device through risers located in the center of the cooling tower. Thanks to the high tower, one part of the vapors returns to the cycle, and the other is already carried away by the wind in the form of steam (the same smoke). Because of this, dampness, fog and icing are not formed in the area in winter.


All nuclear power plants consume a huge amount of industrial water, primarily for cooling components and assemblies. Naturally, the water heats up. Since water often moves in a closed loop (that is, it does not drain into the river, but goes back to cool the units), it should be cooled. This is necessary, first of all, to increase the cooling efficiency - the colder the water, the better it will cool the equipment.

 

The principle of operation of a cooling tower is quite simple. The cooling process in cooling towers occurs due to the partial evaporation of water and heat exchange with air. The water in the cooling tower flows down the sprinkler, escapes in drops or a thin film. At this time, air flows along the sprinkler. There is such a regularity: in cooling towers, when 1% of water evaporates, the temperature of the remaining water drops by 6 C. The loss of liquid is replenished by an external source. Moreover, fresh water, if necessary, is processed (filtered).
The most complex element of a cooling tower is an exhaust tower, the design of which is mainly determined by the material from which it is built.
Hot water enters the cooling tower, where, depending on the type and design of the cooling tower, it is cooled to the required temperature.


In cooling towers, air convection is carried out by natural draft or wind. Concrete cooling towers can be over 100 meters high. In this case, the irrigated area will reach 3500 square meters. Basically, tower cooling towers are used to cool large volumes of water from thermal power plants or nuclear power plants.


It was planned to build two towers to cool the water from the fifth and sixth reactors. At the time of the accident in 86, the first tower was almost finished, while the second was just beginning to be built.