The efficiency of a machine is in its capability to convert energy from one form to another. For a centrifugal pump, two processes are involved: converting mechanical energy into hydraulic energy and converting electrical energy into mechanical energy. Many things could affect how well these processes take place, as discussed next.
Switching on/off frequently
Frequent on-and-off cycles increase power consumption in the pump because of the high surge created during the start. If you are using instant start-up, this can especially be very detrimental to efficiency.
Cavitation is the formation of bubbles in the centrifugal pump impeller. A strong shock wave forms when these bubbles collapse. This not only causes noise and consumes energy, but also damages the pump. Decreased pressure and flow are sure to affect pump efficiency significantly. How do you counter this issue? The best remedy is proactive action through preventative and predictive maintenance.
Design Point Change
Changing the design point is not a problem, but if not accompanied by respective modifications, the efficiency of the pump could be affected. When you first selected the pump, it must have been for certain parameters and specifications. When you decide to change the design point, do not ignore the pump because any alteration to the flow rate will affect cavitation, energy costs and so on.
Lack of Pump Indicators
If you want to understand your pump performance, power, pressure and flow are important parameters. You may not be able to compare pump performance to its Best Efficiency Point (BEP) if these gauges are unavailable. Operating the equipment blindly can lead to inefficient performance easily.
Poor Pump Repair
In the pursuit of low maintenance costs, some pump owners opt for non-OEM parts for repairs. This short-term cost-saving method can actually cost more in terms of lost efficiency. Such parts have been proven to affect pump performance negatively.
If you are seeking to enhance the efficiency of your pump, you know the areas to check. Restriction to passages within the pump, pump design and lack of indicators are just some of the reasons behind inefficiency.