JPH10281843A - Multi-phase flow meter - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To provide a multi-phase flow meter capable of obtaining a flow rate for each component of a mixed object having a non-uniform distribution. SOLUTION: In a multiphase flow meter for detecting a flow rate of a plurality of substances of a conductive measurement fluid for each component, a measurement pipe through which a measurement fluid flows, an electromagnetic flowmeter provided in the measurement pipe, A component ratio sensor provided in the measurement pipe line and calculating a volume ratio of the mixture of the measurement fluid; and a calculation circuit for calculating a flow rate of each mixture of the measurement fluid from the measurement signal of the component ratio sensor and the electromagnetic flow meter. It is a multi-phase flow meter characterized by comprising:

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-phase flow meter for a conductive fluid for measuring a flow rate of a conductive fluid containing air bubbles or impurities or a fluid containing a non-conductive fluid mixed with a conductive fluid. Things. More specifically, the present invention relates to a multi-phase flow meter capable of preventing a measurement error based on a non-uniform distribution of a mixed object and obtaining a flow rate for each component.

[0002]

2. Description of the Related Art FIG. 2 is an explanatory view of the structure of a conventional example generally used in the past. For example, the title is: Industrial Measurement Handbook P112-P120, the date of issue: June 1, 1967.
0, edited by Yokogawa Electric Corporation, published by Tokyo Denki University Press.

In FIG. 1, reference numeral 1 denotes a measurement pipe through which a measurement fluid 2 flows. Reference numeral 3 denotes an electromagnetic flow meter provided in the measurement pipe 1. Here, 4 is an air bubble mixed in the measurement fluid 2.

In the above configuration, the flow rate of the measurement fluid 2 is measured by the electromagnetic flow meter 3.

[0005]

The electromagnetic flowmeter 3 has high accuracy and high reliability in measuring a conductive fluid. However, when measuring the flow rate of the measurement fluid 2 in which bubbles or impurities are mixed in the measurement fluid 2 or the non-conductive fluid is mixed in the conductive fluid, the electromagnetic flow meter 3 determines that the entire measurement fluid 2 is conductive. Since it is output as a sexual fluid, it is overestimated by the flow rate of the contaminant, causing an error. The present invention
This is to solve this problem.

SUMMARY OF THE INVENTION An object of the present invention is to provide a multi-phase flow meter which can prevent a measurement error based on a non-uniform distribution of a mixed object and can determine a flow rate for each component.

[0007]

In order to achieve this object, the present invention provides: (1) a multi-phase flow meter for detecting the flow rates of a plurality of substances of a conductive measuring fluid for each component; A measuring pipe, an electromagnetic flow meter provided in the measuring pipe, a component ratio sensor provided in the measuring pipe, and calculating a volume ratio of the mixture of the measurement fluid; An arithmetic circuit for calculating the flow rate of each mixture of the measurement fluid from the measurement signal of the flow meter. (2) An absolute pressure gauge for measuring an absolute pressure of a measurement portion of a portion where the device is disposed, and a thermometer for measuring a temperature of a measurement portion of the portion where the device is disposed. The multi-phase flow meter according to claim 1 or 2. It is what constituted.

[0008]

In the above arrangement, the arithmetic circuit calculates the flow rate of each mixture of the measurement fluid from the measurement signals of the component ratio sensor and the electromagnetic flow meter. Hereinafter, a detailed description will be given based on embodiments.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an explanatory diagram of a main part configuration of an embodiment of the present invention. In the figure,

Reference numeral 11 denotes a measurement pipe through which the measurement fluid 12 flows. Reference numeral 13 denotes an electromagnetic flow meter provided in the measurement pipe 11. 14 is provided in the measurement pipe 11 and the measurement fluid 12
Is a component ratio sensor that calculates the volume ratio of the mixture.
As the component ratio sensor 14, for example, a density meter, a capacitance sensor, a microwave sensor, a conductivity sensor, or the like is used.

An arithmetic circuit 15 calculates the flow rate of each mixture of the measurement fluid 12 from the measurement signals of the component ratio sensor 14 and the electromagnetic flow meter 13. Here, 16 is the measurement fluid 1
2 are air bubbles mixed in.

In the above configuration, when bubbles or impurities are mixed in the measurement fluid 12, if the flow velocity is large to some extent, the bubbles and the like are dispersed in the measurement fluid 12 to form a flow called a bubble flow. In the case of a vertical pipe or the like, the flow is a so-called annular flow in which a gas flows through the center and a fluid flows around the center.

From the study of electromagnetic flowmeters, when the flow is symmetrical to the axis of the pipe such as a bubble flow or an annular flow, the output of the electromagnetic flowmeter is the output when the entire cross section is occupied by the conductive fluid. Is the same as This is thought to be because the electromagnetic flowmeter measures the flow velocity times the pipe cross-sectional area, and it can be seen that the electromagnetic flowmeter can be used as a flowmeter.

As a specific example, in the case of a mixture of water and gas, consider measuring the flow rate of the mixture of water and gas. What is measured by the electromagnetic flow meter is the product of the water flow rate and the pipe cross-sectional area as described above.

On the other hand, when a capacitance sensor is used as the component ratio sensor 14, the relative permittivity of water is 80 and the relative permittivity of gas is 1, so that the sectional The cross-sectional ratio of the water inside can be measured. By using those outputs, the flow rate of water = flow velocity × water sectional area ratio × pipe sectional area = electromagnetic flow meter output × water volume ratio output of the component ratio sensor. By performing this processing in the arithmetic circuit 15, the flow rate of water can be obtained.

In the case of a bubble flow, since the flow rate of the bubble is the same as the flow rate of the water, the flow rate of the bubble can be similarly obtained by the following procedure. Bubble flow rate = Velocity x (1-water cross section ratio) x piping cross section = electromagnetic flow meter output x (1-water volume ratio output of component ratio sensor)

As a result, by using a system in which the electromagnetic flow meter 13 and the component ratio sensor 14 are combined, the flow rate of the conductive fluid containing air bubbles and impurities can be accurately measured without being affected by the contaminants. be able to. Further, when the contaminant flows in a dispersed manner, a multiphase flow meter capable of measuring the flow rate of the contaminant is obtained.

In the above calculation, known values are used for the dielectric constant and density of each measurement component in advance, but these values change depending on temperature and pressure. The absolute pressure sensor and temperature sensor are used to measure the state of the measurement part, and the permittivity and density of each measurement component at that temperature and pressure are obtained using a calculation formula or table, and the values are used. By doing so, it is possible to obtain a multi-phase flow meter capable of performing accurate measurement even when conditions such as environmental conditions of the measurement fluid change.

In addition, using the output from the absolute pressure sensor and the temperature sensor, even if the measurement point is not in the standard state, the physical property value such as the density and capacitance of each component of the mixture can be obtained by using the physical property table. Can be corrected and converted to a flow rate in a standard state.

[0020]

As described above in detail, according to the first aspect of the present invention, by using a system in which an electromagnetic flow meter and a component ratio sensor are combined, a conductive fluid containing air bubbles and impurities can be removed. The flow rate can be accurately measured without being affected by contaminants. Further, when the contaminant flows in a dispersed manner, a multiphase flow meter capable of measuring the flow rate of the contaminant is obtained.

According to the second aspect of the present invention, there is provided a multi-phase flow meter capable of performing accurate measurement even when a condition such as an environmental condition of a measurement fluid changes. In addition, a multi-phase flow meter that can correct physical properties such as the density and capacitance of each component of the mixture and convert it to a standard flow rate can easily determine the standard flow rate. Is obtained.

Therefore, according to the present invention, it is possible to realize a multi-phase flow meter capable of preventing a measurement error based on a non-uniform distribution of a mixed object and obtaining a flow rate for each component.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a configuration of an embodiment of the present invention.

FIG. 2 is an explanatory diagram of a configuration of a conventional example generally used in the related art.

[Explanation of symbols]

 11 Measurement Pipeline 12 Measurement Fluid 13 Electromagnetic Flow Meter 14 Component Ratio Sensor 15 Operation Circuit

 ──────────────────────────────────────────────────続 き Continued on the front page (71) Applicant 000006507 Yokogawa Electric Corporation 2-93-2, Nakamachi, Musashino-shi, Tokyo (72) Inventor Manabu Fueki 2-9-132 Nakamachi, Musashino-shi, Tokyo Yokogawa Electric Inside (72) Inventor Daisuke Yamazaki 2-9-132 Nakamachi, Musashino-shi, Tokyo Inside Yokogawa Electric Corporation (72) Inventor Shuichi Haruyama 2-9-132 Nakamachi, Musashino-shi, Tokyo Yokogawa Electric Corporation (72) Inventor, Hitoshi Tanaka 2-9-32 Nakamachi, Musashino City, Tokyo Inside Yokogawa Electric Corporation

Claims (2)

[Claims] 1. A multi-phase flow meter for detecting a flow rate of a plurality of substances of a conductive measurement fluid for each component, comprising: a measurement pipe through which a measurement fluid flows; and an electromagnetic flow meter provided in the measurement pipe. A component ratio sensor that is provided in the measurement pipe line and calculates a volume ratio of the mixture of the measurement fluid; and a calculation circuit that calculates a flow rate of each mixture of the measurement fluid from the measurement signals of the component ratio sensor and the electromagnetic flow meter. A multi-phase flow meter comprising: 2. An apparatus according to claim 1, further comprising: an absolute pressure gauge for measuring an absolute pressure of a measurement portion of a portion where the device is disposed; and a thermometer for measuring a temperature of a measurement portion of the portion where the device is disposed. The multi-phase flow meter according to claim 1.