Water pump is a kind of energy conversion machine, energy conversion process is bound to accompany the loss of energy, and efficiency is the measure of this conversion, how to improve the efficiency of the pump, reduce the loss of energy? You have to figure out the energy loss in the pump. The energy loss in the pump mainly includes the following three aspects:
1. Mechanical loss
The main reason is the friction loss between the liquid and the outer surface of the cover plate and the pump cavity (also called disk loss).
The loss of the disk is large, even up to 30% of the effective power. The test shows that the disc loss is proportional to the third power of the rotating speed and to the fifth power of the outer diameter of the impeller.
Therefore, the larger the impeller diameter, the greater the disc loss. Although the disc loss is proportional to the third power of the rotational speed, the external diameter of the impeller decreases with the increase of the rotational speed under a given head, disk loss is reduced to the fifth power, so, with the increase of speed, disk loss does not increase, but decreases, which is one of the reasons for the development of high-speed pumps.
2. Volume loss
A part of the liquid of the impeller is leaked back to the inlet of the impeller through the clearance of the impeller seal ring and can not be used effectively, resulting in loss. Therefore, the seal ring clearance should be as small as possible, but due to processing and assembly reasons, too small clearance may form partial wear or stuck, national standards for various types of pump clearance made special provisions.
3. Hydraulic loss
Pump flow part (from the import to the export) of the liquid flow rate is bound to change the size and direction of the loss, these two parts are hydraulic loss. To reduce the loss of this part, in addition to improving the cleanliness of the flow parts, try to choose an excellent hydraulic model.
