When two different fans are connected in parallel, how should the air pressure be determined?
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There are two different fans, A and B, which are used to extract air from the same pipeline. Given the static pressure of B, the flow rate of A, and the total flow rate in the pipeline, with Qa < Qb, how should the static pressure of A be determined? Pa（,=）Pb?
The fans are connected in parallel, and the wind pressure at the node in front of the fans is the same. If the outlet of the fan is also at the same target point, then the outlet pressure of the fan is also the same. The static pressure of the fans should be the same. The flow rate of fans can vary. If the fan models are different, the operating point of one of the fans may not be at its optimal efficiency point.
1. In the case where the fan outlets are at the same target point, it is also necessary to consider the pressure loss between each fan outlet and the final collection point; therefore, the static pressure values selected for the two fans need not be identical. 2. How should we handle the situation where the fan outlets are not at the same target point? Should the static pressure of a fan with low flow rate be greater than that of a fan with high flow rate? Otherwise, could the low-flow fan fail to draw in air?
In parallel, the wind pressure must be the same; otherwise, the result will be less than 1+1
They must be consistent; otherwise, after connection in parallel, the fan with higher air pressure may draw air back from the fan with lower pressure. 1. If the fans have already been purchased, it is recommended to try them during testing at low temperatures. 2. If it is still in the design phase, it is advised not to use two different fans – instead, use one fan with two air ducts leading out from its outlet
Our company did this before, and as a result the small fans failed to produce sufficient power, reversed direction, and experienced vibration; eventually, by adjusting the inlet opening of those small fans, we managed to get them to operate