Summary of the influencing factors of the efficien

2022-09-22
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Summary of influencing factors on the efficiency of centrifugal pump

through the analysis of the factors affecting the efficiency of centrifugal pump unit, this paper puts forward improvement measures to improve the operating efficiency of centrifugal pump and reduce equipment energy consumption

I. several factors affecting the efficiency of centrifugal pump group

the efficiency of centrifugal pump is the product of mechanical, volumetric and hydraulic efficiency. The efficiency of the pump set is the product of pump efficiency and motor efficiency. The main factors causing the low efficiency of centrifugal pump set are as follows

1. The efficiency of the pump itself is the most fundamental influence. Under the same working conditions, the efficiency of the pump may differ by more than 15%

2. The operating condition of centrifugal pump is lower than the rated condition of pump, with low pump efficiency and high energy consumption

3. The efficiency of the motor remains basically unchanged in operation. Therefore, it is important to choose a high-efficiency motor

4. The influence of mechanical efficiency is mainly related to design and manufacturing quality. After the pump is selected, the later management has little impact

5. Hydraulic losses include hydraulic friction and local resistance losses. After the pump runs for a certain time, it will inevitably cause the surface wear of impeller, guide vane and other parts, increase the hydraulic loss and reduce the hydraulic efficiency

6. The volume loss of pump is also called leakage loss, including three kinds of leakage losses: impeller sealing ring, interstage and axial force balance mechanism. The volume efficiency is not only related to design and manufacturing, but also related to later management. After the pump operates continuously for a certain period of time, due to the friction between various components, the clearance increases and the volumetric efficiency decreases

7. The centrifugal pump is evacuated and idled due to the blockage of the filter cylinder and the air inlet of the pipeline

8. Before the pump is started, employees do not pay attention to the preparation work before the centrifugal pump is started, and the basic operating procedures such as warming up the pump, disc pump and filling pump are not fully implemented, which often leads to cavitation of the pump, causing high noise, vibration and low pump efficiency

II. Measures to reduce the energy consumption of centrifugal pump and improve the efficiency of pump set

1 Replace 14 inefficient centrifugal pumps. During replacement, centrifugal pumps that are close to the actual operating conditions of packaging waste treatment and resource recycling are selected to ensure that the replaced pumps always operate in an efficient state. We have done the efficiency comparison experiment before and after the replacement of the centrifugal pump. The experiment shows that after the replacement of the inefficient and high consumption centrifugal pump, the pump efficiency can be increased by about 10%

2. Application of frequency conversion energy saving technology. For centrifugal pumps whose design parameters are greater than the actual operating conditions, they will always operate in the high-efficiency area after installing frequency conversion and speed regulation devices

3. Promote and apply 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 pump. When selecting new pumps, pumps produced by large manufacturers should be selected to ensure the high efficiency of centrifugal pumps

5. Maintenance of centrifugal pump. (1) Check and adjust the shaft end seal of centrifugal pump frequently to reduce volume loss; (2) When the centrifugal pump has operated for 10000 hours, it should be overhauled to restore the pump efficiency; (3) The bellows sealing technology is popularized and applied in centrifugal pumps to completely eliminate the leakage of centrifugal pumps and improve the volumetric efficiency

6. Regularly clean the slow cylinder when the filter piston rises, and check the pipeline connection to ensure that the liquid inlet pipeline of the centrifugal pump is unblocked

7. Strictly follow the operating procedures of centrifugal pump. Before starting the pump, turn on the pump, open the inlet valve, close the outlet valve, exhaust and vent, and check whether the inlet pressure of the pump meets the requirements. Prevent cavitation of the pump caused by low liquid supply pressure and insufficient flow

8. Regularly test the pump efficiency of centrifugal pumps. For pump groups with low pump efficiency, find out the causes in time and take corresponding measures to solve them

when the centrifugal pump is used to pump the mud flow containing large, medium and small-sized materials in the liquid, the liquid is sprayed into the cylindrical chamber in the tangential direction, thereby forming a vortex, and a part of the liquid is discharged from the chamber in the tangential direction; The slurry is sprayed axially into the chamber, and the eddy current separates the large-size material from the rest of the slurry and liquid; Discharge the remaining mud and liquid from the chamber along the axial direction and spray it into the inlet of the centrifugal pump; The material from the centrifugal pump is used as the spray to form the vortex, which significantly enhances the rigidity and impact resistance of the liquid jet, so as to reduce the wear of the centrifugal pump impeller and improve the efficiency of the centrifugal pump

when the centrifugal pump is used to pump the mud flow with large to small materials in the liquid, the method to reduce the wear of the impeller of the centrifugal pump and improve the efficiency of the centrifugal pump is characterized by: a spraying the liquid into the vortex chamber tangentially to form a vortex, and discharging a part of the liquid from the chamber tangentially; B. the slurry is sprayed axially into the chamber, and the eddy current separates the large-size material from the rest of the slurry and liquid; C remove the remaining mud and liquid from the chamber along the axis of reducing the number of manual rotation, and spray it into the inlet of a centrifugal pump; D using the material from the centrifugal pump as the jet liquid forming the vortex; Therefore, the large-size materials move to the outer circle of the vortex and are discharged. As a result, medium, small and small-size materials and liquids are sprayed into the centrifugal pump. Therefore, the wear of the impeller is reduced and the pump is allowed to run at high speed, so the efficiency is improved

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