SU1317229A1 - Device for automatic protection of heat-emitting surface having source of processing noises - Google Patents

Abstract

The invention relates to the field of power engineering and improves the reliability of the device. The device contains summing amplifiers 6, 11, acoustic sensors 1, 2, amplifiers 3, 4, level 5, 10 detectors, heat flow limiting circuit 9, band-pass filters 7, 12 and detectors 8, 13, converters 14, 15 eg reversive counter 16. Sensors 1, 2 convert acoustic signals into electrical ones. The signal, caused by both boiling noise and technological noise, is fed to the amplifiers. The transfer coefficients of coordinators 5, 10 are set such that they differ by an insignificant and subsequently strictly fixed value. The sign of the difference in the signal levels at the outputs of the detectors 8, 13 determines the direction of synchronous change of the transfer coefficients of coordinators 5, 10. When one of the transfer coefficients of the matching matches is exceeded, the signal level at one of the detectors will exceed the other. The state of the reversible counter will change, leading to a synchronous increase in transmission coefficients. This will happen before the alpha level of the signals at the output from the detectors 8, 13 is entered. The transmission coefficient of one of the coordinators is set so that it provides the best subtraction of the process noise recorded at the output of the steam generating channel, 1 sludge. from S SB to GhE: O

Description

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The invention relates to the power industry and can be used in heat and power plants for various purposes, in particular in the steam boilers of tenl power plants.

The purpose of the invention is to increase the reliability of the device.

The drawing shows the block diagram of the device.

The device contains acoustic sensors 1 and 2, amplifiers 3 and 4, the first level 5 coordinator, the first summing amplifier 6, the first band-pass filter 7, the first detector 8, the heat flow limiting circuit 9, the second level 10 adjuster, the second summing amplifier 11, the second band pass filter 12, second detector 13, voltage converters 14 and 15 - frequency, reversible counter 16.

Acoustic sensor 1 is mounted on a heat-shedding surface (installed at the outlet of the steam generating channel). Acoustic sensor 2 is installed on the source technology. noise (at the outlet of the circulation pump). The outputs of the acoustic sensors 1 and 2 are connected to the inputs of amplifiers 3 and 4, respectively. The output of amplifier 4 is connected to the inputs of matching 5 and 10, the outputs of which are connected to the inverting inputs of summing amplifiers 6 and 11, the output of amplifier 3 is connected to the non-inverting inputs of summing amplifiers 6 and 11, the outputs of which are connected to the inputs of bandpass filters 7 and 12, the outputs of connected with the inputs of the detectors 8 and 13, respectively, the output of the detector 8 is connected to the heat flux restriction circuit 9 and to the input of the converter 14, and the output of the detector 13 to the input of the converter 15, the outputs of the converters 14 and 15 are connected to the input of the re A counter 16 is connected to the control inputs of coordinators 5 and 10.

The device works in the following manner.

Acoustic sensors (piezoelectric) 1 and 2 convert acoustic signals into electrical ones. The electrical signal, caused by both boiling noise and masking process noise, is output from the acoustic sensor 1 to the input

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3. Electr 1c signal, due practically only to technological noise, comes from the output of acoustic sensor 2 to the input of amplifier 4. Amplifiers 3 and 4 amplify the weak output signals of acoustic sensors 1 and 2, respectively. Level 5 Matcher attenuates the signal from the amplifier output.

4 is exactly as much as the noise of the circulating pump decays when passing along the steam generating channel to the installation site of the acoustic sensor 1. From the output of the 5 level matcher, the electrical signal goes to the inverting input of the summing amplifier 6, to the non-inverting input of which the electrical signal from the output of the amplifier 3 .

summing amplifier 6 subtracts and amplifies the signals at its inputs. As a result, the electrical signal, caused only by boiling noise, is removed from the output of the summing amplifier 6 and fed to the input of the band-pass filter 7. The band-pass filter 7 passes only the electrical signal caused by the transition

from bubble boiling to film noise in a certain frequency band. The electrical signal passed the band-pass filter 7, is fed to the input of the detector 8. The latter converts

a variable-polar signal, arriving at 11SH.N at its input, into a unipolar signal taken from its output. Electrical signaling from the outputs of amplifiers 3 and 4 are also supplied to

non-inverting input, summing amplifier 11 and the input of the matcher 10 level, respectively. The order of operation of the 10-level adapter, the sum of its amplifier 11, the band pass

filter 12 and detector 13 are similar to the above described order of operation of a level 5 match, summing amplifier 6 ;, band pass filter 7, and a detector 8. voltage and frequency converters 14 and 15 convert the uniformly changing unipolar signals to their inputs in a sequence of pulses whose frequency is proportional

input level. Izhgulsy from the output of the converter 14 voltage frequency is fed to the input of the subtraction reversible counter 16, and the pulses

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voltage from the converter output 15 —frequency — to the summing input of the reversible counter 16. A parallel double code from the bit outputs of the reversible counter 16 is fed to the control inputs of the coordinators 5 and 10 of the level. The electrical signal from the output of the detector 8 is also fed to the input of the circuit 9 for limiting the heat flux, for example, containing a relay device and a thyristor switch, connected in series in the power supply circuit of the actuator.

Consider the process of finding an extremum. The transfer coefficients of coordinators 5 and 10 levels are set so that they differ by an insignificant and subsequently strictly fixed value. Due to this, the two signal processing channels analyze two points of the curve slightly apart from each other, expressing the dependence of the output signal level of any of the detectors 8 and 13 on the transmission coefficient of the corresponding level matcher. The sign of the difference in the signal levels at the outputs of the detectors 8 and 13 determines the direction of the synchronous change of the transmission coefficients of the level 5 and 10 coordinators. So, if you set the transfer coefficient of the matcher 10 level slightly pre-. the upward gain of the level matcher 5, and the signal level at the output of the detector 8 begins to exceed the signal level at the output of the detector 13, that the frequency of the pulses at the output of the voltage-frequency converter 15 is higher than the frequency of the pulses at the output of the converter 14 16 changes in a positive direction, which leads to a synchronous increase in the transfer coefficients of the level 5 and 10 converters. This continues until the signal levels at the outputs of the detectors 8 and 13 become equal, i.e. the transfer coefficient of the match level 5 will be set, with

VNIIPI Order 2407/33

Man-made games. pr-tie, Uzhgorod, st. Project, 4

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which provides the best subtraction of technological noise from the total acoustic noise recorded at the output of the steam generating channel.

Claims (1)

Invention Formula A device for the automatic protection of the heat-snapping surface, having a source of technological noise, containing its first summing amplifier, to the non-diverting input of which the first acoustic sensor and the first amplifier are connected in series, and the second acoustic sensor installed in the technological noise source, the second amplifier and the first level matching device to the inverting input wherein the output of the first summing amplifier is connected with the input of the heat flow limiting circuit through after a first bandpass filter and a first detector, which are characterized in that, in order to increase reliability, the device further comprises a second level matcher, a second circuit; a second amplifier, a second band filter, a second detector, two voltage-frequency converters and a reversible counter with the summing and counting inputs, the output of which is connected to the control inputs of the first and second level coordinators, the output of the first detector is connected via a second voltage converter - frequency to the input from summarizing the reversible counter, the output of the first amplifier is connected to the non-inverting input of the second summing amplifier, and the output of the second amplifier is connected through the second level matcher with the inverting input of the second summing amplifier, the output connected via a second band-pass filter connected in series, the second detector and the first voltage converter are the frequency to the subtracting input of the reversible counter. Circulation 387 Subscription