Dynamic stress testing method for runner of water turbine

Abstract

The invention relates to a dynamic stress testing method for a runner of a water turbine. The method is characterized by comprising the following steps of: 1) pasting strain gauges at each test point of a water turbine blade to be detected, and connecting each strain gauge with a strain gauge through a signal line, wherein the signal line penetrates into a cable protection pipe for protection, and the cable protection cover protects the signal line and the cable protection pipe; 2) before test, feedback signals of the strain gauges are levered to eliminate static stress; (3) during testing, an instruction is sent out through wireless remote control, after the strain gauge receives the control instruction, signals of the water turbine blade to be detected are detected through the strain gauges, and collected data are stored in a memory card of the strain gauge; and 4) the collected signal is processed to obtain a dynamic stress test result of the water turbine runner to be detected. The method can be widely applied to the field of water turbine runner dynamic stress testing.

Description

technical field [0001] The invention relates to a method for testing the dynamic stress of a water turbine runner, belonging to the field of stress testing of a water turbine runner. Background technique [0002] As the size and capacity of hydraulic units continue to increase, the problems of unit stability and runner cracks caused by hydraulic factors of hydraulic turbines are becoming more and more prominent. Runner cracks are a major problem in the safe and stable operation of hydropower units. They are the core of whether the hydropower units can operate normally. They have attracted widespread attention in the industry and are also a key issue to be solved in the construction of water conservancy and hydropower. [0003] There are many reasons for the vibration and cracks of the runner blades. It is not only affected by the design, manufacture, installation and maintenance quality of the unit, but also related to the operating conditions of the unit and the water flow ...

AI Technical Summary

Problems solved by technology

[0004] Stress testing of hydraulic turbine runner components is a very complicated subject. To study it, the first thing to do is to solve the testing technology of hydraulic turbine runner stress. The progress of hardware technology is relatively slow. This is mainly because the runner part is in the rotating state when the hydraulic unit is running. During the test, the output signal of the strain gauge is transmitted from the rotating part to the fixed test instrument. In the early 1990s, transmission devices such as non-contact capacitive or inductive transmitters and electromagnetic wave transmitters were used in some actual measurements, but the noise of these transmission devices limited the measurement accuracy of the entire measurement system and affected the reliability of the test data

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