Calculation of the power for evaporative coolers
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Current operating conditions: 1 evaporative cooler, equipped with 3 7.5Kw axial flow fans with a rated current of 17.2A, and 1 5.5KW circulation water pump. During debugging, it was found that the water pump was not running while all 3 fans were operating; the current reached 16.5A. Will the current increase after the water pump starts running? The fan manufacturer recommends adjusting the angle of the blades; the question is, if the angle is reduced, will it affect the cooling efficiency?
Do evaporative cooling towers have strict requirements regarding humidity? Dew removal, energy saving, anti-icing.
Someone from the fan factory adjusted the angle of the fan blades, and the current dropped to 0.5A. Has anyone done calculations for evaporative cooling axial flow fans? When water is passed through them, a water film forms in the cooling coil, which affects the resistance at the inlet; it’s similar to when the inlet valve of a ventilator is closed, as this reduces the load. So why is it said that the current increases after water is introduced?
I want to find out whether the motor current of the fan will be overloaded, before and after water is introduced
Overload is generally not an issue, as the diameter of the fan and the angle of its blades are all properly adjusted. Too much water is related to temperature.
Once the spraying is activated, the current drawn by the fan should decrease slightly. Under normal conditions, for a 7.5KW, grade 8 motor fan, a current of 14–15 amps is considered normal; if the fan is running idle, the current may be a bit higher； It is reasonable for normal operation to reach 90% of the rated current
A change in current of 1-2A has very little impact on the heat transfer efficiency of evaporation cooling, so it can basically be ignored；
When you turn on this water pump, the current of the fan will experience a change beyond the limit. This change is due to the water droplets formed by the spray water affecting air flow. It’s hard to determine whether it’s too large or too small. Also, the power of your circulation pump is too high. Our circulation pump with a flow rate of 180 cubic meters only consumes 4 kilowatts. Take a look at yours.