Analysis of frequency conversion pump working principle

As the name suggests, through the frequency of the motor to change the motor speed, so as to achieve the pump flow head and other technical parameters of the adjustment, play a role in control. Compared with the ordinary pump, it has the effect of energy-saving, then what is its specific working principle, Xiaobian following for you to answer. Analysis of variable frequency water pump works one: constant speed pump and variable speed pump: the traditional heating, air conditioning system, is based on the independent quality regulation mode of operation choose circulating pump, pump principle is the pump flow can not be less than the required flow outside the network, the general outside the network The theoretical flow of 1.1 to 1.2 times the head and the user by the total resistance of 1.05 to 1.10 times to choose, then the corresponding shaft power has more than 100%. Can be seen by the constant flow mode of operation, the pump running power consumption is great. Bring the adjustment effect is very good. The pump runs at a constant flow rate. When the load is partially loaded, the required flow rate of the system is reduced. In order to adapt to the change of the flow rate, the valve opening degree adjustment needs to be reduced to change the system characteristic curve, which consumes excessive pressure head and consumes a large amount of electric energy! Change the valve opening to complete the pump operating point adjustment, we can also change the pump speed method: It can be seen: When the pump speed changes, the pump performance curve will change at the same time, and the speed will change with the frequency [Hz] change. Analysis of the performance of the circulating pump shows that: the pump flow, lift and shaft power and pump impeller speed exists between a certain proportion: As can be seen from the pump head and the square of the motor speed is proportional to the pump shaft power and the motor speed cube Is proportional. That is, when the pump flow rate is reduced by 20%, the motor speed should be reduced by 20% and the pump power consumption will be reduced by 50%. When the pump flow rate is reduced by 50%, the motor speed will be reduced by 50% and the pump power consumption by 87.5%. When the system needs to reduce the flow rate, reduce the speed, the corresponding pump flow decreases, the pump shaft power is reduced, the power saving effect is significant. , The use of variable speed regulation, but also to avoid the use of valve adjustment valve head pressure loss unnecessary. Second: speed control principle: When the flow rate decreases, the controller will detect the pressure signal (sensor motor current or speed state). At this point, the controller will signal the frequency converter to lower the output (lower frequency) until the pressure returns to the desired level (set point). Conversely, when the flow rises again, the controller will detect the pressure drop. The controller signals the frequency converter to raise the output (higher frequency) until the pressure returns to the desired level (set point). Third, the overall efficiency of the variable speed pump Usually people refer to the pump efficiency, only the pump efficiency [hp], and in the strict sense, we should measure the total efficiency: Overall efficiency [ht] Evaluation to take into account the motor efficiency [hm] Pump efficiency [hp] and conversion efficiency [hd]. The overall efficiency refers to the P1 to P4 changes. Motor Efficiency Motor efficiency levels and motor loads vary. Technological progress, frequency conversion technology will be more and more recognized and applied by people, with the correct system design (such as the three pump system), and science election pump with pump, allowing users to feel more comfortable at the same time, to more obvious energy-saving effect. Industry Internet (Xiamen) Technology Co., Ltd. Asia Pump Network Editor: Zeng Fenfen (QQ / WeChat: 235592927) http://beng.liuti.cn/ (Service Hotline: 400-6030-811)