1. Several factors affecting the efficiency of centrifugal pump units
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. The main factors causing low efficiency of centrifugal pump units are as follows:
1.The efficiency of the pump itself is the fundamental reason. Under the same working conditions, the efficiency of pumps may differ by more than 15%.
2. The operating conditions of acid and alkali resistant centrifugal pumps are lower than the rated conditions of the pump, 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, the pump inevitably causes surface wear on components such as impellers and guide vanes, increases hydraulic losses, and reduces hydraulic efficiency.
6. The volume loss of a pump, also known as leakage loss, includes three types of leakage losses: impeller sealing ring, inter stage, and axial force balancing 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 acid and alkali resistant 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.
2. Measures to reduce energy consumption of centrifugal pumps and improve pump efficiency
1. Replace the inefficient chemical centrifugal pump. When replacing, a centrifugal pump that is close to the actual operating parameters is selected to ensure that the replaced pump always operates at high efficiency.
2. Application of frequency conversion energy-saving technology. For centrifugal pumps with design parameters greater than the actual operating conditions, after installing a variable frequency speed regulation device, they always operate in the high-efficiency zone.
3. Promote the application of new energy-saving products such as high-efficiency and energy-saving permanent magnet speed regulating motors and dual power motors on major centrifugal pumps.
4. Selection of centrifugal pumps. When selecting a new pump, the pump produced by the brand manufacturer should be chosen to ensure high efficiency of the centrifugal pump.
5. Regularly clean the filter cylinder, check the pipeline connection, and ensure that the inlet pipeline of the centrifugal pump is unobstructed.
6. Strictly follow the operating procedures of the centrifugal pump. 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.
7. 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.
When a centrifugal pump is used to pump a slurry flow containing large, medium, and small-sized materials in a liquid, the liquid is sprayed into a cylindrical chamber along the tangential direction to form a vortex, and a portion of the liquid is discharged from the chamber along the tangential direction; Inject the mud axially into the chamber, and the vortex separates large-sized materials from the remaining mud and liquid; Remove the remaining mud and liquid from the chamber along the axial direction and spray them into the inlet of the centrifugal pump; Using the material extracted from the centrifugal pump as the jetting liquid to form the vortex, thereby reducing the wear of the centrifugal pump impeller and improving the efficiency of the centrifugal pump.
