RU2008617C1 - Method for measuring of each-constituent rate of gas- fluid flow having three constituents and running over pipeline, and device for implementation of this method - Google Patents

Abstract

FIELD: measuring devices. SUBSTANCE: method involves preliminary mixing of flow by mixer which is rotated by motors, measuring moment at motor shaft and measuring dielectric permeability by means of radio wave transducer, determination of relative content of fluid by measured moment and determination of flow rate of each constituent according to corresponding equations. Device has mixer placed at pipeline, primary transducer, radio wave transducer and eddy flow meter. Mixer has drive and moment gauge. Radio wave transducer has tunable oscillator controlled by extremum regulator which is connected to detector and clock. Regulator control switch which is connected to first and second registers. Moment gauge, registers and output of flow meter are connected to computing unit. Computing unit has subtraction units, comparators, switch, divider, integration units, multipliers, setters and adders. EFFECT: increased functional capabilities. 3 cl, 5 dwg

Description

 The invention relates to measuring technique and can be used to measure the flow rate of a three-component flow, in particular to the oil industry in controlling the flow rate of oil wells.

 A known method of measuring the component flow rate of a three-component gas-liquid flow, including measuring its dielectric constant using a capacitive sensor and density using a γ-density meter [1].

 The disadvantage of this method is the large error in the measurement of flow due to the slip of the phases of the stream.

 Closest to the proposed technical solution are a method for measuring the component flow rate of a three-component gas-liquid stream passing through the pipeline, including preliminary preparation of the stream, sequential measurement of its density, phase and flow ratio and processing of the measurement results, and a device containing a flow preparation unit, installed in series with it a radio wave a liquid phase composition sensor, a flow meter and a density meter, and a computing unit [2].

 The disadvantages of this technical solution are the large dimensions of the device, necessary to ensure high-quality separation of the flow, and a large measurement error with the inevitable appearance of deposits on the walls of the primary transducers.

 The aim of the invention is to improve the measurement accuracy and reduce the size of the device.

, где M^*(t) - максимальный момент на валу двигателя;
M(t) - измеренный момент на валу двигателя;
M_o - момент холостого хода, и расход каждой из фаз по формулам:
Q_o= Q

Q_w= Q

Q_g = Q ˙ ( 1 - α ) , где Q - измеренное значение расхода потока;
ε - измеренное значение диэлектрической проницаемости потока;
Q_g, Q_o, Q_w - значения расхода потока каждого из компонентов;
ε_g , ε_o , ε_w- эффективные диэлектрические проницаемости соответственно газовой и жидких фаз, а в устройстве для измерения покомпонентного расхода трехкомпонентного газожидкостного потока, проходящего по трубопроводу, содержащем устанавливаемые на трубопроводе последовательно узел подготовки потока, радиоволновый датчик состава жидкой фазы и расходомер, и вычислительный блок, узел подготовки потока выполнен в виде активной мешалки с приводом и установленным на ее валу датчиком момента, соединенным с первым входом вычислительного блока, датчик состава жидкой фазы выполнен в виде первичного преобразователя, представляющего собой замкнутый зигзагообразный проводник, размещенный на диэлектрической полой трубе, внутренний диаметр которой равен диаметру трубопровода, и соединен через элементы связи с детектором и перестраиваемым генератором с двумя выходами, при этом первый выход перестраиваемого генератора подсоединен с элементу связи, второй - к входу ключа, выходы которого соединены соответственно с первым и вторым регистрами, выход которых подключен к второму и третьему входам вычислительного блока, первый вход перестраиваемого генератора соединен с выходом экстремального регулятора, вход которого подключен к выходу детектора, второй вход перестраиваемого генератора соединен к первым выходом тактового генератора, второй выход которого подключен к управляющему входу ключа, а расходомер подсоединен к четвертому входу вычислительного блока, при этом расходомер содержит корпус с проточной камерой, тело обтекания, нагревательный элемент, чувствительный элемент с двухплечевым передающим элементом, прижим, два вторичных преобразователя и блок вычитания, тело обтекания выполнено с внутренней полостью и установлено в камере поперек ее оси, нагревательный элемент размещен во внутренней полости тела обтекания, чувствительный элемент выполнен в виде пластины и консольно закреплен основанием к стенке проточной камеры параллельно телу обтекания в плоскости продольных осей тела обтекания и проточной камеры, передающий элемент выполнен в виде балки с балансиром на одном конце и разжимающейся цангой на другом, размещен вне проточной камеры соосно чувствительному элементу и сопряжен с вторичными преобразователями с помощью прижима, закрепленного в корпусе так, что вторичные преобразователи, установленные параллельно плоскости пластины и соединенные с блоком вычитания, взимодействующим с передающим элементом симметрично относительно его поперечной плоскости, проходящей через продольную ось прижима, при этом прижим контактирует с передающим элементом в местах, расположенных на продольной плоскости передающего элемента, проходящей через центр массы передающего элемента с закрепленными на нем цангой и балансиром, а разжимающаяся цанга размещена в основании чувствительного элемента с возможностью продольного перемещения.The goal is achieved by the fact that in the method of measuring the component flow rate of a three-component gas-liquid flow passing through the pipeline, including preliminary preparation of the flow, sequential measurement of the phase to flow ratio and processing of the measurement results, the flow is prepared by mixing it with a stirrer rotated by the motor, the moment on the shaft is successively measured engine and dielectric constant of the flow, and when processing the measurement results determine the relative content of liquid ty α in the stream from conditions
α =

where M ^* (t) is the maximum moment on the motor shaft;
M (t) is the measured moment on the motor shaft;
M _o - idle time, and the flow rate of each of the phases according to the formulas:
Q _o = Q

Q _w = Q

Q _g = Q ˙ (1 - α), where Q is the measured value of the flow rate;
ε is the measured value of the dielectric constant of the flow;
Q _g , Q _o , Q _w - flow rate values of each of the components;
ε _g , ε _o , ε _w are the effective dielectric constants of the gas and liquid phases, respectively, and in a device for measuring the component flow rate of a three-component gas-liquid flow passing through a pipeline containing a flow preparation unit, a radio wave liquid phase composition sensor, and a flowmeter and a computing unit, a flow preparation unit is made in the form of an active mixer with a drive and a torque sensor mounted on its shaft connected to the first input of the computing unit a, the liquid phase composition sensor is made in the form of a primary transducer, which is a closed zigzag conductor placed on a dielectric hollow pipe, the inner diameter of which is equal to the diameter of the pipeline, and connected through communication elements to the detector and a tunable generator with two outputs, while the first output of the tunable the generator is connected to the communication element, the second to the key input, the outputs of which are connected respectively to the first and second registers, the output of which is connected to the second and To the inputs of the computing unit, the first input of the tunable generator is connected to the output of the extreme controller, the input of which is connected to the output of the detector, the second input of the tunable generator is connected to the first output of the clock generator, the second output of which is connected to the control input of the key, and the flowmeter is connected to the fourth input of the computing unit wherein the flow meter comprises a housing with a flow chamber, a flow body, a heating element, a sensing element with a two-arm transmitting element m, clamp, two secondary transducers and a subtraction unit, the flow body is made with an internal cavity and is installed in the chamber across its axis, the heating element is placed in the internal cavity of the flow body, the sensitive element is made in the form of a plate and cantileverly fixed with the base to the wall of the flow chamber parallel to the body flow around the plane of the longitudinal axes of the body and the flow chamber, the transmitting element is made in the form of a beam with a balancer at one end and an expanding collet at the other, placed outside the flow channel measures coaxially with the sensitive element and is coupled to the secondary transducers by means of a clamp fixed in the housing so that the secondary transducers mounted parallel to the plane of the plate and connected to the subtraction unit interacting with the transmitting element symmetrically with respect to its transverse plane passing through the longitudinal axis of the clamp, the clip contacts the transmitting element in places located on the longitudinal plane of the transmitting element passing through the center of mass of the transmitting ele ment with a collet and a balancer fixed on it, and an expandable collet placed at the base of the sensing element with the possibility of longitudinal movement.

 In FIG. 1 shows a functional diagram of a device that implements the method; in FIG. 2 is a block diagram of a computing unit; in FIG. 3 - the primary Converter of the radio wave sensor of the composition of the liquid phase; in FIG. 4 is a block diagram of a flow meter; in FIG. 5 is a section AA in FIG. 4.

 A device for measuring the component flow rate of a three-component gas-liquid flow contains (Fig. 1) an agitator 1, a primary transducer 2 of a radio wave sensor and a vortex flowmeter 3. sequentially mounted on the pipeline. The mixer is equipped with a drive 4 and a torque sensor 5. The radio wave sensor also includes a tunable generator 6, controlled by an extreme controller 7 connected to the detector 8, and a clock generator 9, a control key 10 connected to the first register 11 and the second register 12. The computing unit 13 has its own frequency inputs 14-16 (Fig. .2) is connected respectively with registers 11,12 and flowmeter 3, and with the information input M (t) - with the moment sensor 5.

 Computing unit 13 contains (Fig. 2) subtraction blocks 17-19, comparators 20-22, keys 23-28, divider 29, integrators 30 and 31, multipliers 32-47, setpoints 48-50 and adders 51-54.

 The primary transducer 2 is a closed zigzag conductor 55 (Fig. 3), laid on a hollow dielectric pipe 56, connected via communication elements 57 to the generator 6 and detector 8.

 The flow meter 3 comprises a housing 58 (FIG. 4) with a flow chamber 59, a flow body 60, a heating element 61, a sensing element 62, a two-arm transmitting element 63, a clamp 64, two secondary transducers 65, a subtraction unit 66, a balancer 67 and an expandable collet 68 .

, (1) где M^*(t) - максимальный момент на валу двигателя;
M(t) - измеренный момент на валу двигателя;
M_o - момент холостого хода.To measure the component flow rate of a three-component gas-liquid flow, it is necessary to have information about the composition of the stream and the speed of each phase. In the proposed method, the phase velocities due to the use of the mixer are the same, which greatly simplifies the measurement procedure. The composition of the flow can be determined by the measured moment on the shaft of the mixer and the value of the dielectric constant of the flow. The moment on the shaft of the mixer is a measure of the gas content in the stream due to the fact that it depends on the viscosity and density of the mixed stream. The viscosities of liquid phases and their densities are close to each other and significantly higher than similar parameters of the gas phase. As a result of this, the moment on the mixer linearly decreases with increasing gas content. However, during operation due to the influence of adverse factors (bearing wear, deposits, etc.), the value of the maximum moment changes, and therefore the gas content must be determined taking into account the changed maximum moment. Thus, the relative liquid content in the stream α is determined by the formula
α =

, (1) where M ^* (t) is the maximum moment on the motor shaft;
M (t) is the measured moment on the motor shaft;
M _o - idle time.

 The dielectric constant of the flow depends on the ratio of its constituent substances and their dielectric constant.

где Q - измеренное значение расхода потока;
ε - измеренное значение диэлектрической проницаемости потока;
Q_o, Q_w, Q_g - значение расхода потока каждого из компонентов.The value of the dielectric constant of the flow ε can be measured using a radio wave sensor, and
ε _g V _g + ε _w V _w + ε _o V _o = ε, (2) where ε _g , ε _o , ε _w are the effective permittivities of the gas and liquid phases, respectively. Given that the relative contents of the components are related by the ratio
V _g + V _w + V _o = 1, (3) from the expressions (1), (2) and (3) it follows that the flow rate of each of the components can be determined by the formulas:

where Q is the measured value of the flow rate;
ε is the measured value of the dielectric constant of the flow;
Q _o , Q _w , Q _g - the value of the flow rate of each of the components.

 The method is implemented as follows. The controlled flow passes through the pipeline, where it is mixed with a mixer 1. As a result of this, all components are uniformly mixed and acquire the same speed, and the moment on the mixer is measured. Then, the obtained homogeneous stream passes sequentially through the radio wave sensor 2, where its dielectric constant ε and flow meter 3 are measured, where the total flow rate Q is determined. Using the measured moment on the mixer in accordance with formula (1), determine the relative liquid content in the stream α, after which by the formula (4) determine the flow rate of each of the components.

T

(t)+M_mg(t)= M(t) T₉=

T

(t)+M_mf(t)= 0,9·M(t) T_f=

где T_g1 = T_f1 = 1 c - постоянная времени фильтра;
T_g2 = 12 ч - постоянная времени фильтра, соответствующая скорости изменения рабочих характеристик привода мешалки;
T_f2 = 36 с - постоянная времени фильтра, соответствующая скорости изменения соотношения жидкостных компонентов в потоке.The estimate M ^* (t) changes over time with a change in the ratio of liquid components in the flow, as well as with a change in the characteristics of the drive. To increase the measurement accuracy α, the value of the estimate M ^* (t) is continuously refined. Moreover, if the current moment M (t) exceeds the estimate M ^* (t), the value of the latter is immediately equal to M (t). When M (t) <M ^* (t), the decrease in the estimate M ^* (t) occurs slowly, not faster than the rate of change of the operating characteristics of the agitator drive. In addition, the minimum value of the estimate M ^* (t) is limited to M _mf (t). The function M _mf (t) also monitors the change in the current moment M (t), but the rate of decrease of M _mf (t) does not exceed the rate of change in the ratio of liquid components in the stream. M ^* (t) =

T

(t) + M _mg (t) = M (t) T ₉ =

T

(t) + M _mf (t) = 0.9M (t) T _f =

where T _g1 = T _f1 = 1 c is the filter time constant;
T _g2 = 12 h - filter time constant corresponding to the rate of change of the operating characteristics of the stirrer drive;
T _f2 = 36 s is the filter time constant corresponding to the rate of change of the ratio of liquid components in the stream.

Based on this, the current value M ^* (t) is determined: the signal corresponding to the measured value moment M (t) is supplied to the first filter subtracting unit 17, through the multiplier 36 to the second filter subtracting unit and to the divider 29 as a dividend. The signal from the outputs of one of the filters is used as a divider. If the signal from the output of the first filter is greater than the signal from the output of the second, then the logical signals from the outputs of the comparator 21 open the key 25 and close the key 26, while allowing passage of the signal divider from the output of the first filter to the input. Otherwise, the signal from the output of the second filter is input to the divider. The filter time constants depend on the ratio of the signals at their inputs and outputs. If, for example, the input signal of the first filter exceeds its output signal, then the logic signals from the outputs of the comparator 20 open the key 24 and close the key 23, thereby ensuring the passage of the signal through the multiplier 35, which corresponds to the filter time constant T _g1 . Otherwise, the signal passes through the multiplier 32, as a result of which the filter time constant T _{g2 is set} . In the second filter, the comparator 18, the keys 28, 27 and the multipliers 33, 34 perform similar functions. The public key 28 corresponds to the time constant T _f1 , and the public key 27 corresponds to the time constant T _f2 . As a result of this, a signal α is generated at the output of the divider 29.

где f₁ и f₂ - соответственно частоты первого и второго типов колебаний резонатора;
K₁, K₂, K₃, K₄, K₅, K₆ - константы, определяемые при тарировке.When the flow passes through the primary transducer 2, the dielectric constant ε is measured as follows. A closed zigzag conductor 55, laid on a hollow dielectric tube 56, is a radio wave resonator, the frequencies of which depend on ε - the dielectric constant of the flow passing through the pipe. Moreover, studies have shown that when using the first and second types of oscillations of this resonator, it turns out that even in the presence of deposits on the walls, the dielectric constant of the flow and the value of deposits d can be determined by the formulas

where f ₁ and f ₂ - respectively, the frequencies of the first and second types of oscillations of the resonator;
K ₁ , K ₂ , K ₃ , K ₄ , K ₅ , K ₆ - constants determined during calibration.

The tunable generator 6 maintains the generation frequency equal to the resonance, since the signal taken from the detector 8 has an extremum at the resonant frequency, and the extremal regulator 7, controlling the operation of the generator 6, supports this frequency. The clock generator 9 generates a sequence of clock pulses that transfer the generator 6 in the region of the first and second resonant frequencies and simultaneously alternately connect the output of the generator 6 through the key 10 to the registers 11 and 12, where the values of the frequencies f ₁ and f ₂ are stored, which are fed to the computing unit 13. The multipliers 37, 39, the master 49 and the adder 51 calculate ε, and the multipliers 38,40, the master 49 and the adder 52 calculate d according to the relations (5).

 The flow meter 3 operates as follows. The measured flow is supplied to the flow chamber 59. The flow body 60 installed in the flow chamber transverse to its axis generates vortices, the frequency of which is directly proportional to the flow rate, which interact with the sensing element 62, made in the form of a plate and fixed by the base to the wall of the flow chamber in the plane the longitudinal axes of the body and flow chamber, causing bending deformation of the sensing element in a direction perpendicular to the specified plane. At the same time, the transmitting element 63, made in the form of a beam and mating with the secondary transducers 65 by means of the clamp 64, is deformed, since the expandable collet 68 fixed at its end is located at the base of the sensing element. Two identical secondary transducers, interacting with the transmitting element symmetrically with respect to its transverse plane passing through the longitudinal axis of the clamp, convert the frequency signals of deformation of the transmitting element, delivered to them in antiphase with equal amplitudes, into their corresponding signals of a different kind of energy, for example, electric, which are received the inputs of the block 66 subtraction, forming the output signal of the flow meter.

 The design of the flow meter allows you to increase the accuracy and reliability of measuring flow rates when exposed to adverse factors such as vibration of the pipeline, high levels of pressure and pressure pulsations of the measured medium, a wide range of temperature changes of the measured medium, the presence in the measured medium of low-melting substances that can stick to the elements of the flow meter.

 So, due to the fact that the transmitting element is made in the form of a beam with a balancer at one end and an expandable collet at the other and is coupled to two secondary transducers by means of a clamp fixed in the housing and fixing the position of the transmitting element so that the secondary transducers interact symmetrically with the transmitting element relative to its transverse plane passing through the longitudinal axis of the clip, while the clip is in contact with the transmitting element in places located on the longitudinal plane I transmit of an element passing through the center of mass of the transmitting element fixed on it and balance collet and secondary converters are connected to subtraction unit, increases the accuracy of the flowmeter due to reducing the influence of vibration noise on the output signal.

 Since the sensitive element is connected to the secondary transducers by means of a transmitting element with an expandable collet at the end, which is placed outside the flow chamber coaxially with the sensitive element, and the expandable collet is placed at the base of the sensitive element with the possibility of longitudinal movement, the accuracy and reliability of the flow meter when measuring the flow rate increases flows with high pressure levels, pressure pulsations in a wide range of temperature changes.

 The execution of the body of the flow around the internal cavity in which the heating element is located prevents the formation of deposits on the body of the flow when measuring flows with the presence of fusible substances that can stick to the elements of the flow meter, which increases the accuracy of the measurement.

The signal from the flow meter 3 is fed to a multiplier 47, from which signals are proportional to the value of Q. In turn, the multiplier 41 multiplies ε by 1 / (ε _w - ε _o ); a multiplier 42 multiplies α by (ε _w - ε _g ) / (ε _w - ε _o ); a multiplier 43 multiplies α by (ε _g - ε _o ) / (ε _w - ε _o ); the setter 50 generates a signal ε _g / (ε _w - ε _o ); adders 53 and 54 summarize the signals arriving at them, and the subtraction unit 19 generates a signal (1-α), which, after multiplying with the corresponding signals arriving at the multipliers 44-46, give a result corresponding to formula (4). (56) 1. KH Frantzen, E. Dykesteen. Field Experience Wiht the CM1 Multi-phose Fraction Weter Paper 3.3. North Sea Flow Measurement Work spop 1990. National Engineering Laboratory, East Kilbride, Glasgow, 1990.

 2. Underwater three-phase flow meter. Oil, gas and petrochemicals abroad. 1989, N 9, p. 44-45.

Claims (3)

1. The method of measuring the component flow rate of a three-component gas-liquid flow passing through the pipeline, including preliminary preparation of the flow, sequential measurement of the phase to flow ratio and processing of the measurement results, characterized in that, in order to improve the measurement accuracy, the flow is prepared by mixing it with a rotary motor stirrer , sequentially measure the moment on the motor shaft and the dielectric constant of the flow, and when processing the measurement results determine relative liquid content a in the stream from conditions
a =

where M ^* (t) is the maximum moment on the motor shaft;
M (t) is the measured moment on the motor shaft;
M _about - the moment of idling,
and the flow rate of each phase according to the formulas
Q _o = Q

Q _w = Q

Q _g = Q (1 - a),
where Q is the measured value of the flow rate;
ε is the measured value of the dielectric constant of the flow;
Q _g , Q _o , Q _w - the value of the flow rate of each of the components;
ε _g , ε _o , ε _w are the effective dielectric constant of the gas and liquid phases, respectively.  2. A device for measuring the component flow rate of a three-component gas-liquid flow passing through the pipeline, comprising a flow preparation unit, a radio wave liquid phase composition sensor and a flow meter, and a computing unit, which is characterized in that, in order to reduce the dimensions and improve the measurement accuracy, the flow preparation unit is made in the form of an active mixer with a drive and a torque sensor mounted on its shaft connected to the first input of the computing unit, a sensor the rest of the liquid phase is made in the form of a primary converter, which provides a closed zigzag conductor placed on a dielectric hollow pipe, the inner diameter of which is equal to the diameter of the pipeline, and communication elements are connected through the detector with a tunable generator with two outputs, the first output of the tunable generator connected to the element communication, the second - to the key input, the outputs of which are connected respectively to the first and second registers, the outputs of which are connected to the second and third in odes computing unit, a first input of the tunable oscillator coupled to the output extreme regulator having an input connected to the output of the detector, a second input of the tunable oscillator coupled to the first output clock, a second output of which is connected to the control input of the key, and the meter is connected to a fourth input of the computing unit.  3. The device according to claim 2, characterized in that, in order to improve the accuracy and reliability of measurement under the influence of adverse factors, the flow meter comprises a housing with a flow chamber, a flow body, a heating element, a sensing element with a two-arm transmitting element, a clamp, two secondary transducers and a subtraction unit, wherein the body of the flow around is made with an internal cavity and installed in the chamber transversely to its axis, the heating element is placed in the internal cavity of the body of the flow, the sensitive element is made lining and is cantileverly fixed by the base to the wall of the flow chamber in the plane of the longitudinal axes of the body of the flow and the flow chamber, the transmitting element is made in the form of a beam with a balancer at one end and an expandable collet at the other, placed outside the flow chamber coaxially with the sensing element and is coupled to the secondary transducers with by means of a clamp fixed in the housing so that the secondary converters mounted parallel to the plane of the plate and connected to the subtraction unit interact with the transmitting element symmetrically with respect to its transverse plane passing through the longitudinal axis of the clamp, while the clamp contacts the transmitting element in places located on the longitudinal plane of the transmitting element passing through the center of mass of the transmitting element with a collet and balancer fixed to it, and an expandable collet is located at the base of the sensitive element with the possibility of longitudinal movement.

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