Method and system for detecting NPSH value of water pump

Abstract

The invention discloses a water pump cavitation residue value detecting method and system. Data collection of a whole detecting process is essentially controlled by an automatic collection mode. Whenapplication information of manual control collection is received, privilege of cavitation early stage data collection is endowed to a manual control mode, and cavitation value collection in an automatic collection process is suspended. When the cavitation early stage data collection is completed, the privilege of cavitation early stage data is countermanded. According to the cavitation early stagedata being compared with critical cavitation value, whether the cavitation occurs or not is judged. When the water pump caivtation reaches the critical cavitation value, the automatic collection modeis used for completing collection and calculation of water pump cavitation value, and accurate value of the water pump caivtation residue value is obtained.

Description

technical field [0001] The invention relates to a method and system for detecting the NPSH value of a water pump. Background technique [0002] NPS is an important technical index of water pumps, which involves the performance and service life of pump products, so accurate testing of this index is of great significance to manufacturers and users. The cavitation phenomenon of pumps of different types and structures is not regular when it reaches the critical cavitation value. Even for the same type of pumps, the NPSH value of each pump is not completely the same. Although the current test is generally used However, because the cavitation phenomenon of the water pump has a characteristic, that is, when the water pump is about to reach the critical NPSH value, the cavitation value changes suddenly from a slow change to a continuous and rapid change until the critical cavitation value (this value is the cavitation index value of the water pump), and the cavitation value continu...

AI Technical Summary

Problems solved by technology

[0005] The method of manual control of microcomputer acquisition can ensure the effective detection of the pre-cavitation process of the pump, because the operator can flexibly determine the data collection point in the process of cavitation according to the slow changes of the main basic parameters of the pump’s flow rate and head, but when the cavitation occurs There is no obvious change in the external characteristics of the water pump during erosion, and the cavitation value suddenly changes to a continuous and rapid change. Manual control of the collection cannot guarantee the collection of objective and real cavitation values;

[0006] The way of computer automatic collection can ensure the authenticity of cavitation value, but because of the different models of water pumps, the performance of cavitation varies widely, even if the pumps of the same model and batch are affected by factors such as raw materials, processing accuracy, and processing technology, cavitation There is also a big difference in performance, that is, the process of cavitation is irregular, and the computer automatic collection method can only collect data points in the early stage of cavitation at fixed intervals according to a fixed program, so it is impossible to obtain a scientific and comprehensive cavitation Process curve

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