SU676891A1 - Turbomachine working blade oscillation indicator - Google Patents

Description

one

The invention relates to the field of power plant engineering, mainly to turbomachines with an axial compressor, and can be used for their strength adjustment.

A known indicator of oscillations of a working turbomachine arm, comprising an input scaling amplifier, level discriminators, memory triggers and an output driver. The indicator allows to record the excess of a certain level of the amplitude of oscillations of the input signal. It provides for the accumulation of a signal in the meter in order to eliminate false positives. However, the indicator, signaling an excess of the level of oscillations, does not allow for the computation of their physical nature, which precludes its use for the early diagnosis of synchronous self-oscillations of the turbomachine blade.

The aim of the present invention is to provide an early diagnosis of synchronous self-oscillations of turbomachine blades.

This goal is achieved by the fact that the indicator additionally contains three bandpass tunable filters connected by inputs to the output of a scaling amplifier, and outputs to the inputs of the corresponding level discriminators, two level ratio blocks, the outputs of which are connected through their discriminators to the inputs of the corresponding memory triggers, two circuits And, the input of the first of which is associated with the outputs of the level discriminators, and the output with the input, as well as an additional output driver, connected by an input through its a discriminator of the level with the output of the second filter and with the inputs of both blocks of the level ratio, wherein the outputs of the first and third filters are connected respectively to the inputs of the first and second blocks of the level ratio.

FIG. 1 shows a typical energy spectrum with synchronous self-oscillations; in fig. 2 is a block diagram of an oscillation indicator of turbomachine blades.

The oscillation indicator contains an input amplifier 1, discriminators 2-4 frequencies, such as narrow-band tunable filters, which are controlled by controlling effects 5-7 for scanning in frequency, discriminators of level 8-13, signal level ratios 14 and 15, triggers 16 and 17 memories, logic circuits And 18, 19, output drivers 20 and 21 signals.

The input signal is fed to the amplifier

1, in which a signal is scaled to a predetermined scale. After that, it enters discriminators 2-4 frequencies, made, for example, in the form of narrow-band filters tunable in frequency. From the output of filter 3, the signal arrives at discriminators 9 and 13 of the level and in the scheme for determining the relationship of signal levels 14 and 15. At the same time, signals with filter 2 and 4 are fed respectively to discriminators 8, 10 levels, and also at circuits 14 and 15. When the discriminators fire 8-10, the resolution signal is fed to the controlled inputs of the circuits 14, 15 and, when the predetermined ratio of voltages 14 and 15 is reached, outputs signals to the appropriate discriminators 11 and 12 levels. When they are triggered, the memory triggers 16 and 17 overturn and resolution signals arrive at the AND 19 circuit, as a result of which the shaper 20 is triggered, which signals the occurrence of characteristic three peaks in the oscillation energy spectrum of the blades, i.e. the occurrence of synchronous self-oscillations. When the actuation level of the discriminator 13 is exceeded, the shaper 21 is triggered, signaling that the level of vibration of the blades has exceeded the dangerous level.

Thus, the indicator allows, in the pace of the experiment, to detect synchronous auto-oscillations of the working blades at an early stage of their formation, as well as the presence of dangerous levels of oscillations regardless of their physical nature, and thereby significantly reduce the risk of product breakage. In addition, at the stage of strength adjustment of the turbomachine blades, the indicator allows to reliably diagnose synchronous self-oscillations of the blade crowns on the basis of single tests without additional experiments with

reproduction of the same revolutions. This saves the life of the test product, reduces the cost of the experiment and reduces the time of the experiment.

Claims (1)

Invention Formula Blade oscillation indicator 0 turbo masks containing input scaling amplifier, level discriminators, memory triggers and output driver, different By the fact that, in order to ensure early diagnosis of synchronous self-oscillations of turbo-blades working blades, it additionally contains three band-tunable filters connected by inputs to the output of a scaling amplifier, and outputs to the inputs of the corresponding level discriminators, two level ratio blocks, the outputs of which are connected through their discriminators The inputs of the corresponding memory triggers, the two AND circuits, the first of which is connected to the outputs of the level discriminators, and the output to the control inputs of the blocks and levels, wherein the inputs of the second AND circuit coupled to the outputs of flip-flops memory, and 0 output - with the input of the output shaper, as well as an additional output shaper connected by an input through its level discriminator with the output of the second filter and with 5 inputs of both level ratio blocks, with the output of the first and third filters connected, respectively, with the inputs of the first and second level ratio blocks. 0Sources of information taken into account during the examination 1. USSR Copyright Certificate No. 204633, cl. G 01M 9/00, 1967. HZ tpui.i