Electric motors are crucial power devices in production, and their importance in daily life and work is self-evident. Energy conservation during motor use is also a common concern. Below, we will discuss some energy-saving methods for water pump motors.
1. A large horse pulling a small cart
When the motor load factor is less than 0.4, the motor power should be adjusted by replacing it with a motor of a lower power rating than the original one, and the motor load factor should be adjusted to around 0.6 to 0.7.
2. Replace the triangular rubber belt with a nylon flat belt.
It's simple and easy to implement, with no special technical requirements. Only basic calculations and replacing the pulley are needed. If conditions permit, replacing the indirect drive of the electric motor with a direct drive water pump can improve efficiency by 2-3%.
3. Replace with an energy-saving electric motor
① Application of Y-series (basic series) motors
It adopts a Y-type energy-saving motor, replacing the J2 and JO2 products from the 1960s. Adopting international standards, it improves efficiency and stall torque, reduces size, and enhances control over current noise and vibration. It also features a reasonable structure, aesthetically pleasing design, good versatility, and long service life.
②Uses YX (derived series) high-efficiency motors
This series of motors features low-loss, high-efficiency operation, with a frame center height of H100-H280 mm; power range of 1.5kW-90kW; and 2, 4, or 6 poles. Compared to the Y-series motors, it offers an average efficiency increase of 3% and an average loss decrease of 28.6%, comparable to current high-efficiency motors from abroad. However, these motors are 30% more expensive than the Y-series. This type of motor is suitable for applications with long annual operating times and high load rates, such as textiles, chemicals, fans, and water pumps.
4. Energy-saving retrofit of water pump motors
① Replacing the fan motor with an energy-saving one results in ventilation losses accounting for a large proportion of the total losses. Therefore, minimizing ventilation losses will have a significant effect on energy saving. Moreover, for the JO2, modifying the external fan and shroud does not require any changes to any internal components.
② Replacing ordinary slot wedges with magnetic slot filler (CC material or magnetic putty) smooths the stator core slot openings of the motor. After curing, it firmly bonds with the slot wall, thus forming a magnetic slot wedge. This improves the motor slot tooth effect, reduces copper, iron, mechanical, and stray losses, and provides a new energy-saving approach for the retrofitting of energy-consuming motors.
5. Use conductors with larger cross-sections.
Using larger cross-section conductors not only allows for light-load operation but also significantly extends lifespan and results in substantial energy savings (using copper core cables, etc.).
6. Pay attention to the cleaning and lubrication of bearings and windings.
Proper lubrication of bearings, clean windings, correct installation, and good maintenance can enable electric motors to save energy during operation.
Excessive or substandard grease will increase friction loss and reduce efficiency; it will also cause oil to splash onto the windings, damaging them. Therefore, during maintenance, grease should be added appropriately, and high-quality lithium-based grease should be used. At the same time, it is necessary to prevent moisture and harmful gases from entering the motor and to maintain the winding temperature above zero degrees Celsius.
7. Automatic reactive power compensation is adopted.
The load on a water pump motor is inductive, with its current vector lagging behind its voltage vector. This type of load consumes both active and reactive power, with the reactive power consumption exceeding the active power consumption. To increase cosφ, a capacitor with the opposite reactance characteristic to the inductive reactance is connected in parallel across the load. This uses capacitive reactive power (negative) to offset the inductive reactive power (positive). In reality, the reactive power fluctuations in the inductor and capacitor are exactly 180° apart. That is, when the inductor absorbs energy, the capacitor releases energy, and vice versa. Because of this characteristic, parallel capacitors are widely used in power transmission, transformation, and distribution equipment to improve power factor.
Compensation method: In the application of automatic reactive power compensation, an empirical formula is derived: the reactive operating current of the capacitor is 56% of the motor load operating current.
8. Uses S10 type energy-saving transformer
The improvement of motor power factor is directly related to the rational selection of power transformer capacity and model, and is constrained by factors such as reactive power compensation. Therefore, from the perspective of energy saving, it is important to replace the SL and SL1 series energy-consuming transformers with S7, SL7, SZ7, and SLZ7 series 10-35kV transformers as soon as possible. These transformers adopt 45° fully oblique joints, no punching, fiberglass tape binding, and high-quality grain-oriented cold-rolled silicon steel sheets for the core. The winding conductors use acetal enameled wire, and new materials, structures, and processes such as plate-shaped heat sinks are used. Compared with older models of the same level, these transformers have advantages such as lower losses, smaller size, lighter weight, energy saving, and reduced operating costs.
9. Water pump selection, commissioning and maintenance
The pump driven by an electric motor is a complete system. The efficiency of the pump directly affects the power consumption of the electric motor. The operating efficiency of the pump is interrelated with its size, flow rate, flow volume, and rotational speed. Appropriate selection should be made to determine operating conditions that meet production requirements while achieving optimal efficiency.
Regularly adjust the impeller's balance and improve its surface finish, adjust the axial clearance and replace the inlet ring, improve the inlet and outlet water pipes, reduce the number of bends, and remove unnecessary impellers. Clean and lubricate regularly; otherwise, increased frictional resistance will lead to increased power consumption.
10. Improve organizational measures for energy conservation.
Conserving electricity involves a wide range of issues, including mindset, methods, and technology, and requires cooperation from all sides. Therefore, management must be given high priority, including setting electricity consumption quotas, establishing reward and punishment mechanisms, and regularly maintaining and testing electrical equipment. This includes upgrading high-energy-consuming equipment, promoting the use of new energy-saving products, and establishing a sound energy equipment record management system. To this end, it is essential to establish and strengthen energy conservation management organizations, especially the energy departments of small urban and rural enterprises. These organizations should be thoroughly rectified and strengthened, and their responsibilities effectively implemented.
