Reasons for excessive power consumption of multistage centrifugal pumps
The reasons for excessive power consumption of multistage centrifugal pumps may involve multiple aspects, mainly including the design of the pump, the use environment and the maintenance status. The following is a detailed analysis of these reasons:
1. Design factors
Improper impeller specifications: If the inlet diameter of the impeller is too small or the outlet diameter is too large, the pump efficiency will be reduced, thereby increasing power consumption. Reasonable design of the inlet and outlet diameters of the impeller is the key to improving pump efficiency and reducing power consumption.
The gap between the impeller and the pump body is too large: If the gap between the impeller and the pump body is too large, it will increase the leakage inside the pump, reduce the efficiency of the pump, and increase power consumption. Therefore, when designing, ensure that the gap between the impeller and the pump body is appropriate.
The head and flow rate are not matched: The head and flow rate of the multistage centrifugal pump are interrelated. If the head is too low and the flow rate is too large, the pump will operate in the low efficiency area, thereby increasing power consumption.
2. Environmental factors
Transport liquid properties: If the viscosity of the transported liquid is large or the proportion exceeds the original set value, the resistance of the pump will increase, resulting in increased power consumption. In addition, if the transported liquid contains impurities or particulate matter, it will also increase the wear and power consumption of the pump.
Pipeline system resistance: If the resistance of the pipeline system exceeds or falls short of the preset value, it will affect the operating efficiency of the pump. When the resistance is too large, the pump needs to consume more energy to overcome the resistance, resulting in increased power consumption.
Pump speed is too high: If the pump speed is too high, it will increase the flow and head of the pump, but it will also increase the power consumption. Therefore, when using a multi-stage centrifugal pump, the appropriate speed should be selected according to actual needs.
3. Maintenance factors
Bearing wear or damage: Bearings are one of the important components of the pump. If the bearings are worn or damaged, the rotation resistance of the pump will increase, thereby increasing power consumption. Therefore, the bearings need to be checked and replaced regularly.
Impeller surface wear or fouling: Impeller surface wear or fouling will reduce the efficiency of the pump and increase power consumption. Therefore, the impeller needs to be cleaned and inspected regularly to ensure that its surface is smooth and free of dirt.
Mechanical seal failure: The failure of the mechanical seal will increase the leakage in the pump, reduce the efficiency of the pump and increase the power consumption. Therefore, it is necessary to regularly check the sealing effect of the mechanical seal and replace the damaged seals in time.
4. Other factors
Irrational matching of the pump and the motor: The matching between the modified pump or the replaced pump and the motor is unreasonable. For example, if the motor power is too small, the pump will consume too much power during operation.
The pump outlet valve is opened too wide: If the pump outlet valve is opened too wide, the pump pressure will be too low and the pump displacement will exceed the value specified on the nameplate too much, thereby increasing power consumption.
