Supercharger turbine blade vibration monitoring method based on pressure pulsation

Abstract

The invention discloses a supercharger turbine blade vibration monitoring method based on pressure pulsation. The method comprises the steps that pressure information, pulse signals and rotating speed information of turbine blades are detected through a sensor unit; the maximum inherent frequency and the minimum inherent frequency of the blade at the normal temperature are collected; a corresponding inherent frequency under a thermal-state operation condition is obtained, and a resonance rotating speed range of the turbine blade is pre-estimated; a turbine is controlled to operate in a related blade resonance mode, and the blade inherent frequency is obtained by adopting a turbine resonance rotating speed traversing method: selecting a section of turbine blade resonance rotating speed range containing the actual resonance frequency multiplication of the blade, synchronously collecting pressure, rotating speed and phase discrimination signals under the condition of turbine blade speed increasing or speed reducing operation, and in combination with a pulse signal generated by a phase discrimination sensor, subdividing the signal of which the blade vibration inherent frequency is filtered out according to each rotation circle of the turbine so as to enable the signals to correspond to the turbine blades one by one, thereby determining the turbine blade with the maximum blade vibration.

Description

technical field [0001] The invention relates to the technical field of on-line detection of turbine blade vibration of an exhaust gas turbocharger, in particular to a method for monitoring the vibration of a turbocharger turbine blade based on pressure pulsation. Background technique [0002] The exhaust gas turbocharger uses the high-temperature, high-pressure and high-speed exhaust gas discharged from the engine to drive the turbine to rotate at high speed, thereby driving the coaxial compressor impeller to inhale and compress a large amount of fresh air and send it into the engine cylinder. The exhaust gas turbocharger is not only used to reduce the size of the engine under the same power output, but also can greatly improve the engine's power, fuel economy and reduce emissions. [0003] Turbines are usually designed to have identical blades, and ideally they should. In reality, however, actual turbine blades vary in material properties (mainly Young's modulus) and geome...

AI Technical Summary

Problems solved by technology

This method has the following disadvantages: because the turbine blades of the turbocharger are small in size, the strain gauges attached to the blades and the high-temperature protective layer will greatly increase the damping of the blades, so the measured strain is different from the real strain; the size is small The shaft of the turbine is very thin, and it is difficult for the lead wires of all strain gauges to be drawn out from the center hole of the shaft, so it is impossible to measure all the turbine blades at the same time, and multiple tests are required; making the test time-consuming and expensive

Its disadvantage is that the test and signal processing are complex and time-consuming, and the test equipment is expensive

Since there is currently no easy way to determine which blade vibrates the most strain due to detuning effects prior to testing, the targeted application of strain gauge measurements

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