What is the hydraulic loss of centrifugal pump?

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

I. impact loss

Each water pump has its own design flow. When it is consumed to work 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, and the liquid flow at the outlet does not have impact with the pump shell, so the efficiency is high. However, when the flow deviates from the design condition, the direction of the liquid flow will deviate from the direction of the blade, resulting in impact.

Vortex loss

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

III. friction loss along the way

Because of the rough surface and viscosity of the water pump, the liquid will produce friction loss when it swims. The loss is expressed by the following formula;

HM = a - coefficient in aq2.

Drawn on a coordinate, it is a parabola with the origin as its vertex.

Among the hydraulic losses of all parts, the hydraulic loss in the impeller is the largest, accounting for about half of the total loss confusing black and white; the second is the hydraulic loss at the turning of guide vane, accounting for about 1 / 4 of the total hydraulic loss, and the remaining 1 / 4 of the hydraulic loss is from the impeller to the guide vane, the guide vane diffuser, the guide vane to the impeller inlet and other parts.

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