Swivel panels principle of operation.

Swivel panels principle of operation is semi-automatic, based on use of wind energy.
Totally, there are four modes of operation of swivel panels: two modes for the summer season and two modes for the winter season.
1.Summer mode of operation.
In summer time there is an insufficient draft inside of the cooling tower and air flow thru it. Therefore, the lower folding shields should be in the open position all the time.
Swivel panels operate in automatic mode.
1.1.Zero wind condition.
Owing to eccentricity of the axis of rotation of swivel panels and ease of their rotation, all panels turn simultaneously and take a completely open position to allow free access of air into the sprinklers.
1.2. Wind presence.
With an increase of the wind velocity up to a certain value i.e. when the wind velocity becomes greater than the draft force of the cooling tower and the room under the sprinklers becomes draughty, the following effect takes place.
Thanks to the same eccentricity of the axis of rotation, panels from the upwind side remain open, whereas panels from the downwind side get closed.  Thus, we have some kind of a trap for the wind which directs all the wind pressure inside of the cooling tower, increasing chilling degree of the water. So, the stronger the wind, the more intensive cooling of the water. In other words, strong wind, always being a negative factor for the chimney type cooling towers, suddenly turns into a positive one.

2. Winter mode of operation.
Changeover from summer to winter mode of operation is done gradually as the outside air temperature goes down and necessity to regulate the quantity of the air coming into the cooling tower.
2.1.First of all, the folding shields must be closed, to follow with the manual adjustment of the air access by rotation of the swivel panel blocks to a certain angle with afterfixing.
2.2.Ice forming prevention in the under-sprinklers’ space, prevention of water subcooling, prevention of overburning of fuel by 10÷15%.
In order to prevent ice formation in the under-sprinklers’ space during spells of severe frost, the swivel panels must be completely closed and fixed in closed position.  
In winter time the steer area of the panels must be free of snow drifts, ice crust and icicles.
2.3. Swivel panels must be visually inspected once a month.
2.4.Technical services are to be carried out as need be and by all means before and after the winter period of operation.

Conclusion: Installation of the swivel panels of new design (vertical) at the cooling tower No. 3 enabled us to increase the heat-extraction = 70 МW/hour at the air temperature minus 10 °С, at minus 20 °С the  heat-extraction doubles due to reduction of steam consumption in the turbine condensers, stage No. 10 and 11 .
In summer season the panels operate in automatic mode under the wind force, thermal capacity of the cooling tower goes up by 25÷30%. Revamping pays back in 2÷3 months.