SU870931A1 - Correlation flowmeter of two-phase media - Google Patents

Description

one

The invention relates to the field of measurement technology and can be used in automatic control systems for measuring volumetric, flow rate, and two-phase media, for example gas / gas mixtures.

A device for correlational output of a two-phase medium is known, which contains two primary converters, an adjustable delay bpok, a multiplying device, an tetrameter and an extremal regulator, which is annular with an adjustable aperture unit.

A disadvantage of this device is the complexity of the circuit due to the need for rapid adjustment and high measurement error.

A two-phase open-flow correlator is known, containing two primary preo (%) azovatvp, two multipliers, an adjustable delay unit, combined with the first primary transducer, the second transceiver, and a constant delay through the first multiplier unit, and

the second inputs of the multipliers are connected to the second primary preamplifier, and their outputs are connected to the subtractor device, which is connected to the adjustable delay unit through the integrator {2 ..

A disadvantage of this device is the complexity of the c & ly and the high measurement error.

The purpose of the invention is to improve the measurement accuracy of the volumetric flow rate by simplifying the flow meter design.

This goal is achieved by the fact that in a correlation flow meter of two-phase media, containing two primary converters, an adjustable clamping unit, two multipliers connected to a subtractor device, which is connected via a integrator to a block regulator. the back leg, two interval formers are introduced, the output of the first primary converter is connected to the second time interval former, the first input of the multiplier and the input of the first time interrupt generator, the output of the clock through the adjustable delay block is connected to the second input of the multiplier, and the output, 1 interrupt 145 perzicheski transform and the output of the second shaper time intervals are connected respectively with the first and second inputs of the second multiplier. The drawing shows a functional diagram of a correlation flowmeter of two-phase media. The flow meter contains medium density primary transducers, which include in their composition radioactive sources I and 2, placed in safety callers 3 and 4, and detection units 5 and 6 of the measuring section of pipeline 7, gamma-ray fluxes 8 and 9, drivers time intervals to and 11, adjustable delay block 12, multipliers. 13 and 14, the subtracting device .15, integrator 16. The flow meter works as follows. The gamma-quanta streams 8 and 9 of radioactive sources 1 and 2, formed by devices 3 and 4, pass through a two-phase medium and enter detection units 5 and 6, where they are converted into a sequence of electrical pulses formed in amplitude and duration. The pulse frequency is associated with an exponential dependence with the average density of a substance in a controlled volume of a two-phase medium. The pulse sequence from the output of the detecting unit 5 is fed to the formers of the intervals U and 11, which are binary counters of the pulses with a given coefficient of succession. The duration of the formed interval is inversely proportional to the frequency of the signal of the first primary transducer. The pulse generated in this way is fed to the input of the adjustable delay unit 12, which includes the control of the 1st clock frequency generator and, delayed by the clock of the generator, enters the input of the multiplier 13, to the second input of which the pulses come from the output of the detecting unit 5. The signal at the output of the multiplier 13 is proportional to the ratio of the pulse frequency at the output of the detecting unit 5 in two adjacent cycles. The combined operation of the second detecting unit 6, the former 11 and 8 14 of the multiplier 14 is similar to the operation of amp. 5.10 and 13 with the only difference that the synchronization of the operation occurs with a clock generator with a fixed frequency, and at the output of the multiplier 14 receive a signal proportional to the ratio of the output frequencies of the detecting units 5 and 6. The ratio of the frequencies is proportional to the square of the average density of the two-phase medium. Since the mean square of the difference is uniquely related to the correlation function and differs from it by the presence of some constant component, the signals at the output of multipliers 13 and 14 correspond to the values of the autocorrelation function obtained by the first primary generator and the mutual correlation function of the signals of the first and second primary signals. converters. The pulses from the multipliers 13 and 14 are fed to the subtracting device 15, from the output of which the difference of the signals is fed to the input of the integrator. The integrated signal difference is fed to the input of the adjustable delay unit 12, changing the generator clock frequency until the signal difference between the multipliers 13 and 14 is zero. According to the value of the adjustable delay at the moment when the difference between the signals of the multipliers 13 and 14 is equal to zero, the value of the volume flow rate of the two-phase medium Radionuclides based on, -241 or Sb-137 can be used as sources of gamma-41 radiation depending on the diameter of the measuring section of the pipeline and the type of controlled two-phase medium. The detec- tive blocks are a spin-spin crystal, a photomultiplier and a pulse shape in amplitude and duration. Interval formers are binary pulse counters with a specified division factor. An adjustable delay unit is implemented in the form of a time of a 1 "-" pulse separating device that fills in the delayed spevieHHoro interval with pulses from the auxiliary generator of the ator, and a controlled clock frequency generator, which synchronizes the operation of the first multiplier 13. The economic effect of using the inventor is achieved by decrease as a result of more accurate

Claims (1)

Claim A correlation flowmeter of two-phase media containing two primary transducers, two multipliers connected to a subtractor, which is connected via an integrator to an adjustable delay unit, characterized in that, in order to increase the measurement accuracy by simplifying the circuit, two time interval shapers are introduced into it, with this output of the first primary Converter is connected to the input of the second shaper time intervals, the first input of the first multiplier I input the first shaper time intervals A signal whose output through the adjustable delay unit is connected to the second input of the first multiplier, and the output of the second primary converter and the output of the second shaper of time intervals are connected respectively to the first> 0 and second inputs of the second multiplier.