SU1523988A2 - Device for measuring average volumetric steam content of medium - Google Patents

Abstract

The invention relates to a measurement technique and, in particular, to determining the characteristics of a two-phase heat transfer fluid. The purpose of the invention is to improve the measurement accuracy by separating fluctuations in the signal from an acoustic transducer. The pulses from the generator 11 excite acoustic signals in the transducer 1, which propagate through the waveguide 2 and the sensitive element 3 located in the pipeline with the test medium. The signals reflected from the beginning and the end of the sensing element 3 are converted into electrical signals and are applied to the keys 4 and 5, which are opened at the required points in time. The signals are detected, and the steam content is judged by the magnitude of the pulsation in relation to them. 1 il.

Description

The invention relates to instrumentation for monitoring ~] the role of the parameters of the coolant in the energy sector, to apparatus for determining the characteristics of a two-phase coolant and is an improvement of the device according to ed. St. No. 1116332,

The aim of the invention is to increase the accuracy of the measurement / a due to the allocation of fluctuations in the signal from the acoustic transducer.

The drawing shows a diagram of the device.

The device contains a measuring acoustic channel, including an electro-acoustic transducer 1, mounted ... at one end of the waveguide 2, the other end of which is connected to the end of the waveguide sensing element 3, keys 4 and 5, the outputs of which are connected through the amplifier & to the inputs of the wild detectors 7 and 8 , voltage ratio meter 9, connected to the outputs of peak detectors 7 and 8, forms of 10 delayed strobe · soy, connected to control nkh .-. l ·: keys, and 11 pulse generator, connected to electroacoustic mu transducer 1, the amplifier and and the shaper 10 delayed strobe-uytulsov. Oyo is equipped with sequentially connected High-Pass Filters 12, an amplifier 13, an amplitude-detector RMS 14 and a low-pass filter 15, and the input of the high-pass filter 12 is connected to the output of the voltage-free voltage meter, Indicator 16 is connected to the low-pass filter 15.

The device operates as follows.

With relatively abundant volumes of vapor containing telnose-free (up to 3O-5OZ), the vapor phase is, as a rule, distributed in the form of bubbles and their conglomerates in the medium. Flowing around the element 3, the coolant ** bombards ”its surface with steam bubbles, which turns out to be wetter fluid to a greater or lesser extent *

As a result, the attenuation of ultrasound in it changes and the voltage at the output of the voltage ratio meter fluctuates. From zero to a certain value of the vapor content (10-152), the effective value of the voltage fluctuations varies linearly.

By isolating the relatively high-frequency component of the pulsations (more than 0.1 Hz), the influence of interference fluctuations and other slowly changing factors is completely excluded — the measurement results, including the departure of the bullets of secondary equipment blocks, aging of the transducers, and others.

This eliminates the influence of signals reflected from the walls of the pipeline with the coolant and internal structural elements.

The electrical pulses generated by the generator 11 are converted by the converter! in ultrasonic and ps waveguide 2 are supplied to the waveguide sensitive element 3. Part of the energy of the ultrasonic pulse is reflected from the junction of the waveguide waveguide sensitive element 3, the other from the free end of the waveguide sensitive element 3. Returning sequentially after each other along waveguide 2, the reflected pulses are converted into electrical and from the output of the converter I, after amplification, they go to the inputs of the keys 4 and 5. They open at the moment the first and second pulses arrive by the signals of the former 10 rye ci rob pulses and at the outputs of the picoelectric. detectors 7 and 8 are formed voltages nrolorznooyalim amplitude pulses reflected from both ends of the waveguide sensor 3.

The 9 measuring instrument will determine A determines the amplitude of their amplitudes, which depends only on the attenuation of ultrasound in the sensing element 3 and does not depend on the conditions at the input waveguide 2.

When a fluid flows around the waveguide, the voltage at the output of the meter 9 is constant.

When lar bubbles appear in the coolant flow, the attenuation of ultrasound in the 3-m sensitive element begins to fluctuate. The pulsation component, filtered by a high-pass filter 12, after amplification is detected by the amplitude detectors 14, smoothed by the low-pass filter 15, and an indicator 16 arrives.

With an increase in the number of vapor bubbles in the flow, the damping pulsations in the sensing element 3 increase, which increases the voltage 'supplied to the indicator 16.

Measurement of the effective value of the pulsations of the attenuation of ultrasound in the sensitive element eliminates the influence of signals reflected from the walls of the pipeline with the coolant and internal structural elements.

Claims (1)

The formula was invented by me. A device for measuring the average volumetric vapor content of a medium according to ed. R 1116382, with the exception of the fact that, in order to increase accuracy, it is equipped with a high-pass filter connected in series, the input of which is connected to output _{10 of} the voltage ratio meter, an additional amplifier, an amplitude detector, and low pass filter.