The efficiency of a self-priming centrifugal oil pump is the product of three efficiencies: mechanical, volume and hydraulic. The efficiency of the pump set is the product of pump efficiency and motor efficiency. The main factors that cause the self-priming centrifugal oil pump unit to be inefficient are the following.
1. The efficiency of the pump itself is the most fundamental impact. For pumps under the same working conditions, the efficiency may differ by more than 15%.
2. The operating condition of the self-priming centrifugal oil pump is lower than the rated working condition of the pump, the pump efficiency is low, and the energy consumption is high.
3. Motor efficiency remains essentially unchanged during operation. Therefore, it is important to choose a high-efficiency motor.
4. The impact of mechanical efficiency is primarily related to design and manufacturing quality. After the pump is selected, the post management impact is small.
5. Hydraulic losses include hydraulic friction and local resistance losses. After the pump is operated for a certain period of time, the surface of the impeller and the vane and the like are inevitably worn, the hydraulic loss is increased, and the hydraulic efficiency is lowered.
6. The volume loss of the pump is also called leakage loss, including three leakage losses of the impeller seal ring, the interstage, and the axial force balance mechanism. The volumetric efficiency is not only related to design and manufacturing, but also related to post management. After the pump is continuously operated for a certain period of time, the gap is increased due to friction between the components, and the volumetric efficiency is lowered.
7. The self-priming centrifugal oil pump is evacuated and idling due to blockage of the filter cylinder, intake of the pipeline, and the like.
8. Before the pump is started, the employees do not pay attention to the preparation work before the start of the self-priming centrifugal oil pump. The basic operating procedures such as the warm pump, the disc pump and the infusion pump are not completely performed, which often causes the cavitation phenomenon of the pump, causing the pump to have large noise and large vibration. Low pumping efficiency.