RU2451885C1 - Method to prevent icing of cooling tower - Google Patents

Abstract

FIELD: power engineering.

SUBSTANCE: method to prevent icing of a cooling tower consists in the fact that an additional flow of cold and dry ambient air is introduced along the perimetre of the upper part of the cooling tower at the angle from 5 to 45 degrees to its vertical axis with the help of fans, and such flow separates warm and moist air inside the cooling tower from a cold wall, which prevents its icing.

EFFECT: invention makes it possible to prevent icing of a cooling tower.

3 dwg

Description

The invention relates to heat engineering and can be used at thermal power plants and industrial enterprises.

A known method of preventing freezing of a cross-flow cooling tower, which serves to transfer heat from liquid to atmospheric air (UK patent GB 2267744, IPC F28C 1/12 of 05/21/1993), based on the use of heat of chilled water, which consists in its repeated flow in opposite directions with simultaneous mixing .

The disadvantage of this method is its low efficiency in the harsh winter conditions of Russia, in which the heat of the cooled water is insufficient to prevent icing of the cooling tower, especially its upper, coldest part.

German patent DE 4231813, IPC F28C 1/00 dated 03.24.1994 describes a cooling tower and its operation based on the use of air preliminarily heated in a special heat exchanger located at the inlet of the cooling tower in a dry ring part, which subsequently must move upwards separate the mixture of wet air and cleaned flue gas from the walls of the tower.

The disadvantage of this method is its low reliability and efficiency in winter conditions due to the mandatory presence of vortex flows inside the tower, which destroy the protective layer of dry air near the wall, and a small amount of dry air ejected from the atmosphere.

This drawback is eliminated by the claimed method due to the forced supply by fans of the required amount of cold (unheated, unlike the prototype) atmospheric air into the upper, most iced, part of the tower.

Figure 1 shows a tower cooling tower, with which the inventive method is carried out. Cooled water is supplied to the lower part of the tower through the water distribution system 1 and 2 and enters the water intake pool 6. The air stream coming in through the blower windows 4 moves vertically upward towards the water. The cooling process occurs due to the evaporation of part of the water when it drains with a thin film or drops of water to a special evaporator 3. When 1% of water is evaporated, the temperature of the remaining water drops by 6 ° С.

After interacting with water, the air is heated and saturated with water vapor. At negative ambient temperatures at the outlet of the tower, moist and warm air, interacting with cold walls, cools down, water vapor condenses and freezes onto the upper part of the walls of the tower. In spring, blocks of ice fall from a height and destroy all elements of the cooling tower.

Figure 2 shows that, to prevent icing of the tower, it is proposed to create an additional stream of cold and dry ambient air with the fans around the top of the tower at an angle of 5 to 45 degrees to its vertical axis, which separates warm and humid air inside the tower from cold wall, which eliminates its icing.

Claims (1)

A method of preventing icing of a cooling tower based on the use of atmospheric air, characterized in that along the perimeter of the upper part of the cooling tower at an angle of 5 to 45 ° to its vertical axis, an additional stream of cold and dry ambient air is introduced by fans, which separates warm and humid air inside the tower from the cold wall, which excludes its icing.

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