What Is The Hydraulic Loss Of Centrifugal Pump?

Oct 29, 2021

The hydraulic loss of centrifugal pump includes impact loss, vortex loss and friction loss along the way.

centrifugal pump

1、 Impact loss

Each pump has its own design flow. When the consumption works under the design flow condition, the liquid flow at the inlet enters the impeller along the blade, so there is no impact with the blade. Similarly, the outlet liquid flow does not impact with the pump shell, so the efficiency is high. However, when the flow deviates from the design condition, the liquid flow direction will deviate from the blade direction and produce impact.

2、 Vortex loss

In the pump, the overflow section is a very complex spatial section. When the liquid passes here, the flow velocity is too small and the direction will change constantly, so vortex loss will inevitably occur. In addition, the vortex loss will also be increased when there are sharp corners, burrs and dead water areas on the overflow surface.

3、 Friction loss along the way

Due to the roughness of the overflow surface of the water pump and the viscosity of the liquid, the friction resistance loss will occur when the liquid swims. The loss is expressed by the following formula;

Hm=AQ2   Where a - coefficient.

Drawing on the coordinates is a parabola with the origin as the vertex.

Among the hydraulic losses of various parts, the hydraulic loss in the impeller is large, accounting for about half of the total loss; The second is the hydraulic loss at the turning of the guide vane, accounting for about 1 / 4 of the total hydraulic loss, while the remaining 1 / 4 hydraulic loss is from the impeller to the guide vane, the diffusion part of the guide vane, and the reverse guide vane to the impeller inlet.

In order to reduce the hydraulic loss of the pump, the change of each section of the liquid flow should be gentle and the speed should be reasonable. Appropriate impeller, guide vane type and inlet and outlet setting angle shall be selected. In addition, the surface finish of flow passage parts shall be improved.