RU2006042C1 - Electrochemical method of measurement of hydrodynamic parameters of flow of current conductive liquid and electrochemical device for its realization - Google Patents

Abstract

FIELD: hydrodynamic measurements. SUBSTANCE: method is based on measurement of current signals from both ends of cathode electrically insulated from current conductive liquid (with the exception of two sections) and on calculation by formulas of values of ultimate diffusion currents used to judge about value of investigated hydrodynamic parameters at points of location of uninsulated sections. This provides for expansion of functional capabilities thanks to measurement of hydrodynamic parameters of motion of current conductive liquid with one transducer simultaneously in two points of flow. Device for realization of the method includes transducer (cathode-anode), source of permanent voltage, two current-to-voltage converters, computation unit and register. EFFECT: expanded functional capabilities. 2 cl, 2 dwg

Description

 The invention relates to the field of hydrodynamic measurements and can be used to measure the hydrodynamic parameters of the motion of an electrically conductive fluid, for example, speed, viscous friction stress, etc.

 A known method of measuring the hydrodynamic parameters of the stream, which consists in measuring the limiting diffusion current flowing through the cathode placed in the stream and determining the desired parameters of the stream by the magnitude of the measured current.

 A device for implementing this method is known, comprising a cathode, an anode, a constant voltage source connected to the anode, a current-voltage converter connected to one of the ends of the cathode, and a recorder.

 A disadvantage of the known method and device for its implementation is the inability to measure the hydrodynamic parameters of the fluid motion by one sensor simultaneously at two points of the stream.

 The purpose of the invention is the expansion of functionality by measuring the hydrodynamic parameters of the motion of an electrically conductive fluid with one sensor at two flow points simultaneously.

и I

с двух концов катода, содержащего два неизолированных от электропроводящей жидкости участка, положения которых соответствуют исследуемым точкам потока, а токи I₁ и I₂, по которым судят об искомых гидродинамических параметрах, определяют по формулам:
I₁=

I $\genfrac{}{}{0ex}{}{\text{(}}{\text{Σ}}$ ¹⁾-

I $\genfrac{}{}{0ex}{}{\text{(}}{\text{Σ}}$ ²⁾ ;
I₂= -

I $\genfrac{}{}{0ex}{}{\text{(}}{\text{Σ}}$ ¹⁾+

I $\genfrac{}{}{0ex}{}{\text{(}}{\text{Σ}}$ ²⁾ , (1) где r₁, r₂, r₃ - сопротивления электрически изолированных участков катода;
r_вх1, r_вх2 - входные сопротивления токоснимающих устройств.This goal is achieved by measuring currents I

and I

from two ends of the cathode, containing two sections that are not isolated from the electrically conductive fluid, whose positions correspond to the studied flow points, and the currents I ₁ and I ₂ , by which the desired hydrodynamic parameters are judged, are determined by the formulas:
I ₁ =

I $\genfrac{}{}{0ex}{}{\text{(}}{\text{Σ}}$ ¹⁾ -

I $\genfrac{}{}{0ex}{}{\text{(}}{\text{Σ}}$ ²⁾ ;
I ₂ = -

I $\genfrac{}{}{0ex}{}{\text{(}}{\text{Σ}}$ ¹⁾ +

I $\genfrac{}{}{0ex}{}{\text{(}}{\text{Σ}}$ ²⁾ , (1) where r ₁ , r ₂ , r ₃ are the resistances of the electrically isolated sections of the cathode;
r _vh1 , r _vh2 - input resistances of current collectors.

 In the device, the goal is achieved by the fact that a second converter is introduced into it, the current is the voltage and the computing unit, and the cathode is made with an electrically insulated surface and sensitive elements in the form of two uninsulated sections of the cathode, the second current-voltage converter connected to the second end of the cathode, the outputs of the first and second converters are connected to the inputs of the computing unit, the output of which is connected to the input of the recorder.

 In FIG. 1 shows a block diagram of a device; in FIG. 2 is an equivalent circuit of an electrochemical sensor.

 The device contains an electrochemical sensor (cathode 1 - anode 2), a constant voltage source 3, two current-voltage converters 4 and 5, a computing unit 6 and a two-channel recorder 7.

 The method is implemented as follows.

 A wire cathode 1 mounted on a holder or a film cathode deposited on a streamlined surface electrically isolated from an electrically conductive liquid is placed in the stream, with the exception of two sections that are sensitive elements of the cathode. The anode 2 is placed on a streamlined surface and connected to a constant voltage source 3.

и I

с двух концов катода поступают на преобразователи ток-напряжение. Исходя из эквивалентной схемы (фиг. 2) можно составить систему двух линейных уравнений относительно токов I₁ и I₂, решив которую, получим формулы (1).In uninsulated sections of the cathode, the reaction of reduction of active ions of an electrolyte solution proceeds. This determines the limiting diffusion currents I ₁ and I ₂ , which depend on the hydrodynamic parameters of the flow of the electrically conductive liquid at the points where the uninsulated sections of the cathode are located. Current signals I

and I

from two ends of the cathode are fed to current-voltage converters. Based on the equivalent circuit (Fig. 2), we can compose a system of two linear equations with respect to currents I ₁ and I ₂ , solving which, we obtain formulas (1).

The calculation of the currents I ₁ and I ₂ occurs in the computing unit 6 according to formulas (1). The values of the limiting diffusion currents from the output of the computing unit go to recorder 7. (56) V. Nakoryakov et al. Electrodiffusion method for studying the local structure of turbulent flows. Novosibirsk Institute of Thermophysics.

Claims (2)

1. The electrochemical method for measuring the hydrodynamic parameters of the flow of an electrically conductive liquid, which consists in measuring the limiting diffusion current flowing through the cathode, placed in the stream and determining the desired flow parameters from the measured current, characterized in that the currents I are measured $\genfrac{}{}{0ex}{}{\text{(}}{\text{Σ}}$ ¹⁾ and I $\genfrac{}{}{0ex}{}{\text{(}}{\text{Σ}}$ ²⁾ from the two ends of the cathode containing two sections that are not isolated from the electrically conductive liquid, the positions of which correspond to the studied flow points, and the currents I ₁ and I ₂ , which are used to judge the desired hydrodynamic parameters, are determined by the formulas
I ₁ = I $\genfrac{}{}{0ex}{}{\text{(}}{\text{Σ}}$ ¹⁾ (r ₁ + r ₂ + r _in1 ) / r ₂ - I $\genfrac{}{}{0ex}{}{\text{(}}{\text{Σ}}$ ²⁾ (r ₃ + r _in2 ) / r ₂
I ₂ = -I $\genfrac{}{}{0ex}{}{\text{(}}{\text{Σ}}$ ¹⁾ (r ₁ + r _in1 ) / r ₂ + I $\genfrac{}{}{0ex}{}{\text{(}}{\text{Σ}}$ ²⁾ (r ₂ + r ₃ + r _in2 ) / r ₂
where r ₁ , r ₂ , r ₃ - resistance of electrically isolated sections of the cathode;
r _vh1 , r _vh2 - input resistances of current collectors.  2. An electrochemical device for measuring the hydrodynamic parameters of the flow of an electrically conductive liquid, comprising a cathode, an anode, a constant voltage source connected to the anode, a current-voltage converter connected to one of the ends of the cathode, and a recorder, characterized in that a second current converter is introduced into it -voltage and a computing unit, and the cathode is made with an electrically insulated surface and sensitive elements in the form of two uninsulated sections of the cathode, and the second converter to-voltage cathode coupled to a second end, the outputs of the first and second current-voltage converters are connected to inputs of a computing unit, whose output is connected to an input of the recorder.

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