RU2611210C1 - Method of measuring amount of each component of multi-component medium in container - Google Patents

Abstract

FIELD: physics, measurement technology.

SUBSTANCE: invention relates to measurement technology and can be used to measure component by component amount (volume) of a multi-component medium in a container, arbitrarily distributed inside said container. In particular, the invention can be used to measure the amount of each component of a multi-component medium in a container in zero-gravity conditions. Disclosed is a method of measuring the amount of each component of a multi-component medium in a container, which is arbitrarily distributed inside said container and containing n+1 components, wherein a section of a double-wire long line with uniform electromagnetic field distribution along it is placed uniformly in the volume of the container, electromagnetic oscillations are excited therein and resonance frequency thereof is measured. The method is characterised by that it further comprises placing n sections of a double-wire long line uniformly in the volume of the container, wherein all sections of the double-wire long line have on their wires a homogeneous dielectric coating, different from others, exciting in said n sections of the double-wire long line electromagnetic oscillations and measuring resonance frequency of each of them, performing combined functional transformation of the measured resonance frequencies of all n+1 sections of the double-wire long line and determining the amount of each component according to the relationship

, where k=1, 2, …, n is the component number, D=det[a_ik] is the equation determinant; D_k is the determinant obtained from D after substituting elements of the k-th column with respective free terms b₁, b₂, …, b_n;

is effective dielectric constant of the k-th component of the i-th channel;

is the effective dielectric constant of the n+1-th component - the initial medium in the reservoir - i-th channnel; ƒ_i is the resonance frequency of the i-th section of the double-wire long line, i=1, 2, …, n;

is the value of ƒ_i in the absence of a multi-component medium in the container, wherein the amount V_n+1 of the n+1-th component is determined from the difference between the volume of the container and the total volume V₁, V₂, …, V_n of n components.

EFFECT: method enables to measure the amount of each component of a multi-component medium in a container.

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Description

The invention relates to measuring technique and can be used to measure the component-wise amount (volume) of a multicomponent medium in a container randomly distributed inside it. In particular, it can be used to measure the amount of each component of a multicomponent medium in a tank under zero gravity conditions.

Known methods for measuring the amount (volume, mass) of the medium contained in any metal container, and implementing their device, which consists in considering this capacity as a volume resonator and measuring its own (resonant) frequency of electromagnetic waves (V.A. Lunkin, B.V. and Sovlukov, A.S., Radio Wave Measurements of Technological Process Parameters, Moscow: Energoatomizdat, 1989, 208 pp. 26-29). These known methods and devices may not be applicable for arbitrary location of the controlled environment inside the tank. In addition, they are applicable only to control two-component media.

There are also known methods of measuring the amount of medium and measuring devices based on them. They are based on the use of long line segments as sensitive elements and the measurement with their use of the level of various media in tanks (Viktorov V.A., Lunkin B.V., Sovlukov A.S. Radio wave measurements of process parameters. M .: Energoatomizdat. 1989.208 p. 84-86). Knowing the level of the medium, determine its amount (volume) in the tank. These technical solutions have a limited scope, not allowing you to determine the amount (volume) of the medium, which is a multicomponent medium, occupying an arbitrary position in the volume of the tank.

There is also a method of measuring the amount of dielectric medium, randomly distributed in the tank (SU 690309, 10/05/1979). This method provides a measurement of the amount regardless of the dielectric constant of the medium. However, it does not make it possible to measure the amount of each component with more than one dielectric medium, the number of components of the controlled medium in the tank.

A technical solution is also known (Viktorov V.A., Lunkin B.V., Sovlukov A.S. Radio wave measurements of technological process parameters. M.: Energoatomizdat. 1989. 208 pp. 108-117), the closest in technical essence to the proposed device and adopted as a prototype. Here, a measurement method is described, characterized by the excitation of electromagnetic waves in a segment of a long line, the conductors of which are uniformly distributed inside a container with a controlled environment. An inductive reactance is connected at the end of a long line segment, at which the distribution of the electric field strength along a long line segment is almost uniform. Thus, taking into account the uniformity of the distribution of a segment of a long line inside the tank, they ensure with high accuracy the independence of the result of measuring the quantity (volume) from the location of the controlled medium inside the tank. By measuring the resonant frequency of electromagnetic waves of such a long line segment, it is possible to determine the amount of medium contained in the tank. However, this technical solution is not applicable if the controlled medium is multicomponent, representing more than one medium (component) with the corresponding electrophysical parameters.

The technical result of the present invention is the expansion of the scope.

, где k=1, 2, …, n - номер компоненты, D=det[a _ik] - определитель системы уравнений; D_k - определитель, полученный из D после замены элементов k-го столбца соответствующими свободными членами b₁, b₂, … b_n;

;

;

- эффективная диэлектрическая проницаемость k-й компоненты i-го канала;

- эффективная диэлектрическая проницаемость n+1-й компоненты - исходной среды в резервуаре - i-го канала;

- резонансная частота i-ого отрезка двухпроводной длинной линии, i=1, 2, …, n;

- значение

в отсутствие многокомпонентной среды в емкости, при этом количество V_n+1 n+1-й компоненты определяют по разности между объемом емкости и суммарным объемом V₁, V₂, …, V_n n компонент.The technical result is achieved by the fact that in the method for measuring the amount of each component of a multicomponent medium in a vessel arbitrarily distributed inside it and containing an n + 1 component, in which a segment of a two-wire long line with a uniform distribution of the electromagnetic field along it is placed uniformly over the volume of the vessel, it is excited in electromagnetic waves and measure their resonant frequency, additionally placed evenly over the volume of the capacitance n segments of a two-wire long line, and all the two-wire long line slices have a uniform dielectric coating on their conductors that is different from the others, excite electromagnetic waves in these n segments of the two-wire long line and measure their resonance frequency for each of them, and carry out a joint functional transformation of the measured resonant frequencies of all n + 1-st segments two-wire long line and determine the amount of each component according to the ratio

, where k = 1, 2, ..., n is the number of the component, D = det [ a _ik ] is the determinant of the system of equations; D _k is the determinant obtained from D after replacing the elements of the kth column with the corresponding free terms b ₁ , b ₂ , ... b _n ;

;

;

- effective dielectric constant of the k-th component of the i-th channel;

- effective dielectric constant of the n + 1st component - the initial medium in the tank - of the i-th channel;

is the resonant frequency of the i-th segment of a two-wire long line, i = 1, 2, ..., n;

- value

in the absence of a multicomponent medium in the tank, the amount of V _{n + 1} n + 1 components is determined by the difference between the tank volume and the total volume of V ₁ , V ₂ , ..., V _n n components.

The proposed method is illustrated in the drawing, which shows a functional diagram of a device for implementing the method.

Capacity 1 is shown here; components 2 ₁ , 2 ₂ , ..., 2 _i , ..., 2 _{n + 1 of a} multicomponent medium; a segment of a two-wire long line 3 _i , i = 1, 2, ..., n + 1; inductance 4; electronic unit 5.

The essence of the measurement method is as follows.

, тангенс угла диэлектрических потерь tgδ). Для проведения измерений предлагается использовать в качестве чувствительных элементов отрезки двухпроводной длинной линии, проводники которой покрыты по всей длине диэлектрическими оболочками. Такое покрытие проводников приводит к необходимости учитывать при рассмотрении электродинамических параметров такой линии не только электрофизические параметры (

и tgδ) контролируемой среды, но и, в целом, результирующую эффективную диэлектрическую проницаемость

двухслойной среды (контролируемой среды и оболочки), тангенс угла диэлектрических потерь tgδ_эфф такой среды, а также соотношение геометрических параметров как части сечения линии, занятого средой, так и оболочкой. При соответствующем выборе параметров оболочки (толщины, материала) проводников линии можно считать, что величина tgδ_эфф является пренебрежимо малой (Викторов В.А., Лункин Б.В., Совлуков А.С. Радиоволновые измерения параметров технологических процессов. М.: Энергоатомиздат. 1989. 208 с. С. 85-86).To measure the component-wise amount (volume), we consider the use of long line segments as sensitive elements (Viktorov V.A., Lunkin B.V., Sovlukov A.S. Radio wave measurements of process parameters. M .: Energoatomizdat. 1989. 208 p. ) We assume that the components of a multicomponent medium have arbitrary electrophysical parameters that are different from each other (dielectric constant

, dielectric loss tangent tanδ). For measurements, it is proposed to use segments of a two-wire long line, whose conductors are covered with dielectric shells along the entire length, as sensitive elements. Such a coating of conductors leads to the need to consider not only the electrophysical parameters when considering the electrodynamic parameters of such a line (

and tgδ) of the controlled medium, but also, as a whole, the resulting effective dielectric constant

a two-layer medium (a controlled medium and a shell), the dielectric loss tangent tanδ _{eff of} such a medium, and also the ratio of the geometric parameters of both the part of the cross section of the line occupied by the medium and the shell. With the appropriate choice of shell parameters (thickness, material) of the line conductors, it can be assumed that the value of tgδ _eff is negligible (Viktorov V.A., Lunkin B.V., Sovlukov A.S. Radio wave measurements of process parameters. M .: Energoatomizdat 1989. 208 pp. 85-86).

исходной многослойной среды (т.е. указанной многослойной среды в отсутствие в емкости контролируемой среды) можно определить для каждого конкретного случая формы проводников отрезка длинной линии и оболочек на них (Иоссель Ю.Я., Кочанов Э.С., Струнский М.Г. Расчет электрической емкости. Л.: Энергоиздат, Ленингр. отделение. 1981. 288 с. С. 259-260).To measure the amount of each component of an n + 1-component medium in a container randomly distributed in it, we consider the use of an n-channel resonance measuring system implemented on the basis of segments of the above long line — resonators, whose conductors are uniformly distributed inside the container. The sensitive elements of these channels - the segments of the two-wire long line under consideration - differ from each other by the transverse distribution of electromagnetic energy due to the difference in the corresponding effective permittivity ε _{eff of the} multilayer medium, characterized by the presence of dielectric shells on the conductors of the two-wire long line segment, and the controlled medium in the capacitance. This leads to a difference in the output characteristics of the measuring channels — the dependences of the resonant frequency of the electromagnetic waves of each segment of the long line on the measured parameters. The values of ε _eff multilayer medium (controlled environment and shells),

the initial multilayer medium (i.e., the specified multilayer medium in the absence of a controlled medium in the capacitance) can be determined for each specific case of the shape of the conductors of a long line segment and shells on them (Iossel Yu.Ya., Kochanov ES, Strunsky MG Calculation of electric capacity. Leningrad: Energoizdat, Leningrad Branch. 1981. 288 pp. 259-260).

One of the ends of each segment of a long line is connected to a generator of high-frequency electromagnetic waves, which is part of the electronic unit. Its opposite end has a terminal reactive load in the form of inductive resistance. The presence of such a load allows, when choosing its value, to ensure a uniform distribution of electric field strength along a length of a long line. This, in turn, with the indicated uniform distribution of the long line segment in the tank volume, ensures with high accuracy the independence of the resonant frequency of electromagnetic oscillations of the long line segment from the location of the controlled medium inside the tank (Viktorov V.A., Lunkin B.V., Sovlukov A. S. Radio wave measurements of technological process parameters, Moscow: Energoatomizdat. 1989. 208 pp. 108-117).

электромагнитных колебаний отрезка длинной линии от количества (объема) диэлектрической среды в емкости выражается следующей формулой (Петров Б.Н., Викторов В.А., Лункин Б.В., Совлуков А.С. Принцип инвариантности в измерительной технике. М.: Наука. 1976. 244 с. С. 68-79):Resonance frequency

electromagnetic oscillations of a segment of a long line on the quantity (volume) of the dielectric medium in the capacitance is expressed by the following formula (Petrov B.N., Viktorov V.A., Lunkin B.V., Sovlukov A.S. The principle of invariance in measuring technique. M: Science. 1976. 244 pp. 68-79):

- начальное (при z=0) значение резонансной частоты

; l - длина отрезка длинной линии; С(ξ) и С₀(ξ) - погонная (т.е. на единицу длины) электрическая емкость отрезка линии в сечении с координатой ξ, занятом и незанятом контролируемой средой соответственно.where z is the total part of the length of the length of the long line, filled with a controlled environment;

is the initial (at z = 0) value of the resonant frequency

; l is the length of a segment of a long line; C (ξ) and C ₀ (ξ) are the linear (i.e. per unit of length) electric capacitance of the line segment in the section with coordinate ξ occupied and unoccupied by the controlled medium, respectively.

To consider this problem, we write formula (1) in the form

- эффективные диэлектрические проницаемости в поперечном сечении отрезка линии с координатой ξ, занятом и незанятом контролируемой средой соответственно;

- погонная электрическая емкость отрезка линии в сечении с координатой ξ, незанятом контролируемой средой, в отсутствие диэлектрических оболочек на проводниках отрезка длинной линии.Here ε _eff (ξ),

- effective permittivities in the cross section of a line segment with coordinate ξ occupied and unoccupied by the controlled medium, respectively;

- linear electric capacitance of the line segment in the section with coordinate ξ unoccupied by the controlled medium in the absence of dielectric shells on the conductors of the long line segment.

и рассматривая равномерное распределение энергии электромагнитного поля по объему резервуара, для однородного отрезка длинной линии (в этом случае

) получимCounting

and considering the uniform distribution of electromagnetic field energy over the volume of the tank, for a homogeneous segment of a long line (in this case

) we get

Let z ₁ , z ₂ , ..., z _n be the parts of line segments immersed in the 1st, 2nd, ..., nth components of a multicomponent medium, respectively; then for the i-th channel we get

- эффективная диэлектрическая проницаемость n+1-й компоненты - исходной среды в резервуаре - i-го канала;

- эффективная диэлектрическая проницаемость k-го компоненты i-го канала.Where

- effective dielectric constant of the n + 1st component - the initial medium in the tank - of the i-th channel;

- effective dielectric constant of the k-th component of the i-th channel.

If the segments of the long line and, therefore, the electromagnetic fields excited in them are evenly distributed in the capacitance, then the linear quantities z ₁ / l, z ₂ / l, ..., z _n / l can be replaced by the corresponding volumetric quantities V ₁ / V ₀ , V ₂ / V ₀ , ..., V _n / V ₀ , where V ₀ is the volume of the tank, V _i (i = 1, 2, ..., n) is the amount (volume) of the i-th component.

After transformations, as is easy to show, formula (4) can be written as follows:

Where

,

,

After transformations (5) for all i = 1, 2, ..., n, we obtain a system of equations, the solution of which gives algorithms for converting the resonant frequencies of electromagnetic oscillations of long line segments in the electronic unit of the measuring device for implementing this measurement method:

where D = det [ a _ik ] is the determinant of the system of equations; D _k is the determinant obtained from D after replacing the elements of the kth column with the corresponding free terms b ₁ , b ₂ , ... b _n . The number of V _{n + 1} n + 1 components is equal to the difference between the volume of the tank and the total volume and the component V ₁ , V ₂ , ..., V _n .

Figure 1 shows a schematic illustration of a tank 1 with a controlled multicomponent (n + 1-component) medium with components 2 ₁ , 2 ₂ , ..., 2 _i , ..., 2 _{n + 1} , randomly distributed inside this tank. In segments of a two-wire long line 3 ₁ , 3 ₂ , ..., 3 _{n + 1} excite electromagnetic waves using generators in the electronic unit 5. Figure 1 shows a diagram of the distribution of one (for simplification) segment of a two-wire long line 3 _i , i = 1, 2, ..., n + 1. Other segments are distributed along the volume of the container in a similar way, have an arbitrary arrangement relative to each other. Their electromagnetic fields practically do not affect the resonance frequencies of other segments of the long line. All segments of the long line occupy a small space inside the capacitance, since their conductors have a small diameter (millimeters) relative to the characteristic size of the capacitance (tens of centimeters or more). At the end of each segment of the long line connected terminal reactive load in the form of inductive resistance 4.

In segments of a two-wire long line 3 ₁ , 3 ₂ , ..., 3 _{n + 1} excite electromagnetic waves using generators in the electronic unit 5. In the same electronic unit measure the values of their resonant frequencies of electromagnetic waves, carry out a joint functional transformation according to the relation (6 ) and thus determine the desired values of the quantity V ₁ , V ₂ , ..., V _n , V _{n + 1 of} all components of the medium.

It is also possible not simultaneous, but sequential excitation in segments of a long line 3 ₁ , 3 ₂ , ..., 3 _{n + 1} electromagnetic waves and measurement of their resonant frequencies. At the same time, their measured values are stored in the electronic unit 5 and, upon completion of the measurement cycle with obtaining data from all segments of the long line, the above functional transformation is performed according to relation (6) with the determination of the values of the quantities V ₁ , V ₂ , ..., V _n , V _{n + 1 of} all components of the medium. Since the measurement cycle is carried out for a very short time, the location of the medium components in the tank is almost invariable during the measurement cycle, which does not affect the measurement results.

Thus, this method allows for high-precision measurements of the component-wise amount (volume) of a multicomponent medium in a container arbitrarily distributed inside it. In particular, it can be used to measure the amount of each component of a multicomponent medium in a tank under zero gravity conditions.

Claims (1)

A method for measuring the amount of each component of a multicomponent medium in a container arbitrarily distributed inside it and containing an n + 1 component, in which a segment of a two-wire long line with a uniform distribution of the electromagnetic field along it is placed uniformly over the volume of the container, electromagnetic waves are excited in it and their resonance is measured frequency, characterized in that it is additionally placed evenly over the volume of the capacitance n of the segments of the two-wire long line, all segments of the two-wire for of the other line have a uniform dielectric coating on their conductors, different from one another, excite electromagnetic waves in these n segments of the two-wire long line and measure their resonant frequency for each of them, carry out a joint functional conversion of the measured resonant frequencies of all n + 1-st segments of the two-wire long lines and determine the amount of each component according to the ratio

, where k = 1, 2, ..., n is the number of the component, D = det [ a _ik ] is the determinant of the system of equations; D _k is the determinant obtained from D after replacing the elements of the kth column with the corresponding free terms b ₁ , b ₂ , ... b _n ;

;

;

- effective dielectric constant of the k-th component of the i-th channel;

- effective dielectric constant of the n + 1st component - the initial medium in the tank - of the i-th channel;

is the resonant frequency of the i-th segment of a two-wire long line, i = 1, 2, ..., n;

- value

in the absence of a multicomponent medium in the tank, the amount of V _{n + 1} n + 1 components is determined by the difference between the tank volume and the total volume of V ₁ , V ₂ , ..., V _n n components.

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