The efficiency of a centrifugal pump is the product of mechanical, volumetric, and hydraulic efficiencies. The efficiency of the pump unit is the product of the pump efficiency and the motor efficiency.
Ⅰ, The main factors causing low efficiency of centrifugal pump units are as follows.
The efficiency of the pump itself is the fundamental impact. Under the same working conditions, the efficiency of pumps may differ by more than 15%.
2. The operating conditions of centrifugal pumps are lower than their rated conditions, resulting in low pump efficiency and high energy consumption.
3. The efficiency of the motor remains basically unchanged during operation. Therefore, choosing a high-efficiency motor is crucial.
The impact of mechanical efficiency is mainly related to design and manufacturing quality. After the pump is selected, the impact on later management is relatively small.
5. Hydraulic losses include hydraulic friction and local resistance losses. After running for a certain period of time, chemical pumps inevitably cause surface wear on components such as impellers and guide vanes, increase hydraulic losses, and decrease hydraulic efficiency.
6. The volume loss, also known as leakage loss, of chemical centrifugal pumps includes three types of leakage losses: impeller sealing ring, inter stage, and axial force balance mechanism. The level of volumetric efficiency is not only related to design and manufacturing, but also to post production management. After running continuously for a certain period of time, due to friction between various components, the clearance increases and the volumetric efficiency decreases.
7. Due to blockage of the filter cylinder, pipeline intake, and other reasons, the centrifugal pump may experience vacuum pumping and idling.
8. Before starting the pump, employees do not pay attention to the preparation work before starting the centrifugal pump. The basic operating procedures such as warm-up pump, disc pump, and infusion pump are not thoroughly executed, which often causes cavitation of the pump, resulting in high pump noise, vibration, and low pump efficiency.
Ⅱ, Measures to reduce energy consumption of centrifugal pumps and improve pump efficiency
1. Regularly inspect and adjust the sealing of the centrifugal pump shaft end to reduce volume loss;
After the centrifugal pump has been running for 10000 hours, it should undergo major repairs to restore pump efficiency;
3. Promote the application of corrugated pipe sealing technology on centrifugal pumps to completely eliminate external leakage and improve volumetric efficiency.
4. Regularly clean the filter cylinder, check the pipeline connection, and ensure that the inlet pipeline of the centrifugal pump is unobstructed.
5. Strictly follow the operating procedures for chemical centrifugal pumps. Before starting the pump, the pump should be turned on, the inlet valve should be opened, the outlet valve should be closed, and exhaust should be carried out to check whether the inlet pressure of the pump meets the requirements. Prevent pump cavitation caused by low supply pressure and insufficient flow rate.
6. Regularly conduct pump efficiency testing on centrifugal pumps, and for pump units with low pump efficiency, promptly identify the cause and take corresponding measures to solve it.
