At present, the main energy-saving technologies for water pumps in China include the following energy-saving technologies: cutting impeller, frequency conversion technology, ternary flow technology and special energy-saving pumps. Let us analyze the characteristics of these energy-saving technologies.
1. Cutting impeller saves energy
As we all know, in the structure of centrifugal pumps, an important part that determines the amount of water and the head is the impeller. Its working principle is that the impeller rotating at high speed drives the liquid inside it to rotate, thereby generating centrifugal force. We have learned in the junior high school physics class. An important factor that determines the magnitude of centrifugal force is the radius of rotation. From this we can see that once the impeller of a centrifugal pump is cut, that is, the diameter of the impeller is reduced, then the The centrifugal force of the internal liquid will definitely become smaller, and the consequence can only cause the parameters such as the flow rate and head of the pump to decrease, which may cause hidden dangers to safety in production.
2. Frequency conversion energy saving technology
The main working principle of frequency conversion is to change the frequency of the pump drive motor by frequency conversion and reduce the speed of the motor to achieve the energy saving effect. The main application range is: ① The load of the motor changes periodically with the needs of the production conditions. Under this working condition, when the production load is reduced, the load of the motor is also reduced. The frequency conversion technology can be used to reduce the speed of the motor at this time, thereby achieving the effect of energy saving, but if the operating conditions are relatively stable In the system, the energy saving rate of frequency conversion technology will be significantly reduced. ② It is applicable to pumps with large margins due to design parameters in some circulating water systems, that is, so-called "big horse-drawn carts". In this case, the frequency of the pump motor is changed by frequency conversion. Reduce the speed of the pump, adjust the Q and H value of the pump, make the actual flow value of the pump lower than the rated flow value of the pump, so as to achieve the purpose of energy saving.
Centrifugal pumps are designed with specific speeds under the best hydraulic characteristics as similar criteria. The geometry of the hydraulic model of the flow channel of each pump must be related to its design parameters Q (flow), H (lift), r / One-to-one correspondence of min (speed) can produce the final efficiency of the pump. Therefore, the hydraulic model and geometric dimensions of the pump impeller cannot be changed correspondingly with the change of the rotation speed. Therefore, the frequency conversion speed regulation reduces the rated speed of the pump, and as a result, the output flow of the pump decreases, the head of the pump decreases, and the actual efficiency of the pump decreases. Lower than the original efficiency value of the pump.
When the performance parameters Q and H of the circulating water pump used in the industrial circulating water system are not large enough, if the actual parameters Q and H of the pump are reduced by using variable frequency speed regulation, the pump flow rate may be reduced too much. Insufficient cooling water in the system causes the water temperature of the cooling water system to rise.
3. Ternary Stream Technology
The ternary flow technology is to divide the ternary three-dimensional space inside the impeller infinitely. By analyzing the working points in the impeller flow path, a complete and realistic mathematical model of the flow in the impeller is established.
Through this method, the analysis of the impeller flow channel can be done most accurately, reflecting the flow field and pressure distribution of the fluid are the closest to reality. The impeller exit is characterized by jet and wake (vortex) flow, which is reflected in the design calculation. Therefore, the designed impeller can better meet the requirements of working conditions, and the efficiency is significantly improved. However, if the impeller of a common water pump is simply replaced with a ternary flow impeller, the energy saving effect may not be as expected, because the ternary flow impeller alone cannot change the entire interior of the pump when the pump casing and other components have been shaped. Water resistance and water loss for all flow components.
4. Energy-saving water pump
Energy-saving special pumps are tailor-made for various types of circulating water systems. Its comprehensive use of various technologies integrates the siphon principle, ternary flow technology and technology patents perfectly. The energy-saving special pumps are designed, opened, and cast. The whole process of processing is controlled to make the design reasonable and the mold opening meets the design requirements. Then the advanced casting process is applied to reduce casting errors. Finally, through careful processing and grinding, the final product is consistent with the design concept and reaches the best state. .
When the fluid circulates inside the energy-saving special water pump, it can present a relatively regular flow state, reduce losses such as inlet shock and outlet wake, greatly avoid the occurrence of turbulence, and reduce the fluid in the design of a single-channel hydraulic model for ordinary pumps. The impact and deflow of water, and avoid the backflow of water between the blades, so that the flow of water between the impellers is closer to the design state, which increases the flow of the pump, reduces unnecessary work, reduces energy consumption, and improves the efficiency of the pump. The water pump using this technology can significantly reduce the effective shaft power of the water pump without any change in the flow rate, and fully meet the operating conditions of the industrial system at full load, without increasing the water temperature of the cooling water system. It has high efficiency, does not change the operating parameters of the system, and has no impact on normal production work.