Pump energy savings of up to 11% – essential information for improving pump efficiency

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Protection plan for improving pump efficiency. Keywords: centrifugal pump, improvement of pump efficiency, energy saving in water pumps, protection of pump impellers, polymer materials, Fosun Blue Company. I. Abstract: This article first analyzes the reasons for the low efficiency of centrifugal pumps. Mechanical losses, volumetric losses, and flow losses, which arise from the structural design of centrifugal pumps, are the main factors contributing to their low efficiency； The operating point of the centrifugal pump deviating from the designed condition results in low operational efficiency ； Low pipeline efficiency is also a cause of energy waste, and methods to address the low actual operating efficiency of centrifugal pumps are proposed, including various measures to reduce the hydraulic losses of these pumps, adjusting their rotational speed, and improving their sealing. With the ongoing shortage of energy, energy-saving and energy development technologies have always been a focus of research. Pumps are widely used in people's lives and are one of the main energy-consuming devices. Due to the structural characteristics of centrifugal pumps themselves, the efficiency of this type of pump is generally low. Analyzing the reasons for the low efficiency of water pumps, as well as finding ways to improve their efficiency and reduce energy consumption, are topics that our company has been researching. Water pumps that operate efficiently can play a significant and positive role in saving energy and reducing costs in industrial production. II. Analysis of the reasons for the low efficiency of centrifugal pumps 1. Various losses within the centrifugal pump lead to a decrease in its operating efficiency. The losses associated with the flow of liquid through the impeller include mechanical losses, flow losses, and volumetric losses; correspondingly, there are mechanical efficiency, volumetric efficiency, and flow efficiency. These losses account for the largest proportion of the factors that affect the pump’s efficiency. The flow-passing surfaces of the pump, such as the volute, are typically made of castings and therefore not machined; as a result, their wall surfaces are rough, which leads to greater friction losses. How to improve the surface smoothness of the wall and reduce frictional resistance is key to minimizing hydraulic losses. 2. The operating condition point of the centrifugal pump deviates from the designed condition, resulting in low efficiency. The operating parameters of a centrifugal pump include speed n, head H, flow rate Qv, and efficiency η; when the head of the centrifugal pump changes, the other parameters also change accordingly. The centrifugal pump achieves its highest efficiency under the designed operating conditions. When a centrifugal pump is selected with too high a head or too large a flow rate, the operating condition deviates from the designed condition, resulting in low efficiency. 3. Low pipeline efficiency: When the flow rate or head of the liquid being transported changes, a common solution is to adjust the valves. Although this method is convenient, it results in high resistance losses in the pipelines, causing the centrifugal pump to operate at low efficiency. 4. Low inherent efficiency of centrifugal pumps: To ensure high operating efficiency of centrifugal pumps, it is necessary to choose high-efficiency models first. However, due to poor quality in maintenance and installation, mechanical losses, flow losses, and volumetric losses increase, preventing these high-efficiency pumps from performing as intended and resulting in them operating at lower efficiency levels. Furthermore, when selecting a centrifugal pump, it is often chosen based on the maximum flow rate and head, with a certain margin taken into account; as a result, there is an overpowered situation that prevents the achievement of minimizing energy consumption. III. Application of polymer material coating technology in pump energy conservation: Hydraulic loss accounts for the largest proportion among the factors affecting pump efficiency. The rougher the wall surface of the pump’s flow-through section, the greater the losses. How to improve the surface smoothness of the wall and reduce frictional resistance is key to minimizing hydraulic losses. Currently, the West **has adopted polymer composite materials for the direct manufacturing of pumps and their components in order to improve efficiency; such technology is not yet available in China. Through years of collaboration with industrial enterprises, the company has successfully applied polymer composite material coatings to pump bodies and impellers, which enhances the smoothness of the flow-through areas, reduces fluid resistance effectively, and significantly improves pump efficiency. These series of corrosion-resistant, abrasion-resistant, and cavitation-resistant polymer composites are also used to withstand wear, corrosion, and cavitation in fluid environments, as well as to cope with alternating deformations and temperature changes; they thus ensure that the materials possess excellent corrosion resistance, cavitation resistance, and wear resistance. The smoothness of its surface is several times that of a cast surface; such a smooth surface reduces fluid stratification within the pump, minimizes turbulence, lowers volumetric and hydraulic losses in the pump, reduces power consumption, and thus increases the overall efficiency of the pump by 5%-10%. Furthermore, polymer composite materials are essentially polymer substances that possess resistance to chemical corrosion; they can prevent media such as air and water from coming into contact with the pump and impeller materials, thereby minimizing rusting and electrochemical corrosion ； At the same time, the high elasticity and smooth surface provided by its unique molecular structure also help to enhance the pump’s resistance to cavitation, thereby improving the pump’s efficiency. IV. Application Example: This pump is used to apply a protective coating to the impeller and pump casing of a new energy power plant’s circulation pumps, in order to improve the efficiency of these pumps. The model of this pump is VP-200L; it has a power output of 30 KW and rotates at 2950 revolutions per minute. As can be seen from the areas marked with red circles in the operation charts, under the same conditions of frequency (48 Hz), pressure (0.35 MPa), and voltage (380 V), the current consumption decreased by 42.348 – 37.394 = 4.954 amps after the application of the polymer material. This resulted in an energy savings of 4.954 ÷ 42.348 = 11%. Based on production data analysis, the annual economic benefit resulting from this repair and protection measure is as follows: 30 KW (power of the motor) × 11% (percentage of energy savings) × 0.65 (cost per unit of electricity) × 24×365 (days per year the pump operates) = 18,790 yuan. V. Repair Steps: 1. First, dry the pump body, then perform sandblasting on the area to be repaired to meet the requirements of SSPC SP-5 (white metal surfaces) ； 2. Use compressed air (free of water and impurities) to blow away the dust, and then immediately clean the surface that has been sandblasted with acetone or anhydrous ethanol, ensuring thorough cleaning ； 3. Mix an appropriate amount of Fushilan polymer metal repair material to fill and level out the concave areas caused by cavitation and erosion wear; the first layer should be thin, and care must be taken to apply the material thoroughly into the pits to ensure they are fully filled ； 4. Wait until the metal repair material has fully cured, then sand the surface of the material to ensure a rough texture. Clean it with acetone or anhydrous ethanol. Prepare an appropriate amount of Fosil Blue, a material resistant to erosion and scouring, and apply it evenly to the protected surface, ensuring that the entire repaired area is covered ； 5. Once the material meets the curing requirements, it can be installed and used. During installation, the repaired area should be protected from impacts and knocks. VI. Case images VII. Conclusion The importance of energy conservation in pumps is recognized; both developed and developing countries strongly advocate for energy savings. As our country enters a stage of rapid industrial development, energy conservation is crucial for the construction and development of **. Pumps are major consumers of energy; according to calculations by the General Machinery Industry Association, pumps account for around 20% of China’s total electricity consumption. Increasing the power efficiency of pumps is crucial for saving energy and reducing consumption.