JPS62192665A - Flow velocity measuring instrument for conductive fluid - Google Patents

Abstract

PURPOSE:To obtain a highly reliable measuring instrument capable of measuring the flow velocity of conductive fluid accurately by applying a magnetic field with constant intensity to the conductive fluid flowing in a tube and detecting the potential difference between two points in the fluid. CONSTITUTION:A magnet 3 is arranged at the outside of a flow passage constituent member 1 such as a tube and a duct constituting the flow passage of the conductive fluid whose flow velocity is to be measured to cover the whole with the magnetic field. The 1st and the 2nd electrodes 5 are inserted into the flow passage constituent member 1 at right angles to the magnetic field while separated in the insertion direction. The electrodes 5 have conductors 5a exposed only at tip parts and other parts insulated electrically by insulators 5b, and at least either of the electrode is allowed to move in the insertion direction. Then the potential difference between the 1st and the 2nd electrodes 5 is detected by a potentiometer 8 to measure the flow velocity.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a flow rate measuring device for a conductive current applied to, for example, a liquid metal experimental device.

[Prior Art] Conventionally, the flow velocity of a conductive fluid such as liquid metal sodium has been measured by using a duct or a pipe with a diameter of approximately 10 am, which constitutes a flow path of the conductive fluid to be measured.
This is done by inserting an eddy current current meter incorporating a differential coil into the required location.

[Problems to be Solved by the Invention] However, when measuring flow velocity using this type of conventional eddy current type anemometer, the diameter of the anemometer probe inserted into the inside of the flow path component is large, so the flow rate is There is a problem in that it is not possible to accurately measure the flow velocity in areas where the velocity gradient is steep, such as near the boundary layer in the channel or in the shear layer area of the jet section.

The present invention has been made to solve the above-mentioned problems, and its purpose is to provide a highly reliable flow rate measurement device for a conductive current that can accurately measure the flow rate of a conductive current. be.

[Means for Solving the Problems] In order to achieve the above object, the current velocity measuring device for a conductive current body according to the present invention has a flow path configuration such as a duct, a pipe, etc. that constitutes a flow path for a conductive current body whose flow velocity is to be measured. A magnet is placed on the outside of the member, the whole is covered with a magnetic field, and the first magnet is placed in the direction perpendicular to the magnetic field. the second electrode.

The first electrode is inserted into the flow path forming member while being spaced apart along the insertion direction, and at least one electrode is movable along the insertion direction. The present invention is characterized in that the flow velocity of the conductive current is measured by detecting the potential difference between the second electrodes.

[Function] According to the above-mentioned device for measuring the flow velocity of a conductive current according to the present invention, when a magnetic field is applied to a conductive current, an electromotive force is induced in the fluid due to the movement of the fluid (Faraday's right-hand rule), and this induced electromotive force is Since the amount of electric power is directly proportional to the strength of the magnetic field and the velocity of the fluid, it is possible to measure the flow velocity at that location by detecting the potential difference between two points in the fluid with a magnetic field of constant strength. .

[Example] Hereinafter, an example of a flow rate measuring device for a conductive current according to the present invention will be described with reference to the drawings.

FIGS. 1(a) to (C) show an example of the configuration of a current velocity measuring device for a conductive current according to the present invention, and FIG. b) is a cross-sectional view showing the details of the measuring section, and FIG. 1(C) is a cross-sectional view showing the details of the electrode required for potential difference measurement.

In the figure, a magnet 3 is placed on the outside of a channel forming member 1 of a duct or pipe that constitutes a flow path of a conducting current medium 2 such as liquid metal sodium whose flow velocity is to be measured so as to sandwich this channel forming member 1. The entire structure is covered with a magnetic field. Also,
As shown in the figure, the lengths of the magnets 3 inserted into the central portions of the magnets 3 in the longitudinal direction are different from each other in the direction perpendicular to the magnetic field (the vertical direction in the figure).

In other words, the first . The second two electrodes 5 are inserted into the channel forming member 1 while being spaced apart along the insertion direction, and each electrode 5 is secured in the insertion direction ( It is configured to be movable along the vertical direction. Furthermore, the above 1. Second
Each electrode 5 is electrically connected to a potentiometer 8 via a lead wire 7, and the potential difference between each electrode 5 is detected.

In addition, in the above, 1. Each of the second electrodes 5 is shown in FIG.
), the conductor 5a is exposed only at its tip,
Other parts are electrically insulated by an insulator 5b. Further, as the magnet 3, either a permanent magnet or an electromagnet may be used, but the dimensions are such that the magnetic flux density is uniform throughout the entire area of the flow path forming member 1. Furthermore, 4 is an electrode holder for holding each of the electrodes 5, respectively.

In the device for measuring the flow velocity of a conductive current configured as described above,
When the conductive current body 2 is flowing inside the channel forming member 1 from the back side to the front side of the paper in FIG. 1(b), if a magnetic field is applied to the conductive current body 2, as shown in FIG. 2, Due to the movement of the conductive current body 2, an electromotive force (E
) is induced (Faraday's law) and a current 1 flows.

In this case, the relationship between the induced electromotive force (E) and the flow velocity V of the conductive current body 2 is expressed as v=E/<8·1) (1). That is, since the magnitude of this current i is directly proportional to the strength of the magnetic flux B and the speed V of the conductive current body 2, the first. A potential difference corresponding to the separation distance 1 between the second electrodes 5 is obtained. And this first one. Since the potential difference between each of the second N poles 5 is introduced into the potentiometer 8 via the lead wire 7, a potential difference (E) corresponding to the flow velocity of the conductive current body 2 at that position is detected. That will happen. Therefore, by converting the indication scale (E) of the potentiometer 8 into a flow velocity from the relationship of equation (1) above, the flow velocity V of the conductive current body 2 at that position can be easily measured. In addition, the first
By traversing each second electrode 5 in a direction perpendicular to the magnetic field, that is, in the vertical direction in the drawing, it is possible to measure the flow velocity (2) of the conductive current body 2 at each position.

As mentioned above, the current velocity measuring device for a conducting current according to this embodiment can measure the precise flow velocity near the boundary layer in the flow channel, which could not be achieved with the conventional large eddy current type current meter probe mentioned above. In addition, the detailed flow velocity in the shear layer portion of the jet portion can be accurately measured and understood, which can greatly contribute to elucidating the structure of the flow in the conductive current body 2.

It should be noted that the present invention is not limited to the embodiments described above, but can also be implemented in the following manner.

First, FIGS. 3(a) to 3(C) show other configuration examples of the current velocity measuring device for a conductive current according to the present invention, and FIG. 1(a)
1(b) is a cross-sectional view showing the details of the measuring section, and FIG. 1(C) is a cross-sectional view showing the details of the potentiometric measurement electrode. In addition, Fig. 3<a>
-(C), the same elements as in FIGS. 1(a)-(C) are designated by the same reference numerals.

In the figure, a magnet 3 is placed on the outside of a channel forming member 1 of a duct or pipe that constitutes a flow path of a conducting current medium 2 such as liquid metal sodium whose flow velocity is to be measured so as to sandwich this channel forming member 1. The entire structure is covered with a magnetic field. Also,
At the center of the magnet 3 in the longitudinal direction, first electrodes 5 are arranged from the upper and lower sides along the direction perpendicular to the magnetic field as shown in the figure.
and the second electrodes 5 are inserted into the channel forming member 1 while being spaced apart from each other along the insertion direction, one electrode, the lower second electrode 5, is fixed, and the other electrode is The upper first electrode 5 is connected to a seal opening device 6 such as a screw type.
a and 6b, it is configured to be movable along the insertion direction (vertical direction). Furthermore, the above 1. Each second electrode 5 is a lead! ! It is electrically connected to a potentiometer 8 via 7 to detect the potential difference between each electrode 5.

In addition, in the above, 1. Each of the second electrodes 5 is shown in FIG.
), the conductor 5a is exposed only at its tip,
Other parts are electrically insulated by an insulator 5b. Further, as the magnet 3, either a permanent magnet or an electromagnet may be used, but the dimensions are such that the magnetic flux density is uniform throughout the entire area of the channel forming member 1, as described above. moreover,
Reference numeral 4 represents an electrode holder for holding each of the electrodes 5 described above.

In the device for measuring the flow velocity of a conductive current configured as described above,
In a state where the conductive current body 2 is flowing inside the channel forming member 1 from the back side to the front side of the paper in FIG. To,
The motion of the conductive current body 2 induces an electromotive force (E) in a direction perpendicular to the magnetic flux B (Faraday's law), and a current i flows.

In this case, the relationship between the induced electromotive force (E) and the flow velocity (2) of the conductive current body 2 is expressed as V-E/(B·Δh) (2). That is, since the magnitude of this current i is directly proportional to the strength of the magnetic flux B and the speed of the conductive current body 2, the first.
A potential difference is obtained between each of the second electrodes 5 according to the separation distance Δh. And this first one. By introducing the potential difference between each of the second electrodes 5 to the potentiometer 8 via the lead wire 7, a potential difference (E) corresponding to the flow velocity (2) of the conductive current body 2 at that position is detected. Therefore, (1) above
By converting the indicating scale (E)' of the potentiometer 8 into a flow velocity from the relationship of the equation, the flow velocity (2) of the conductive current body 2 at that position can be easily measured.

Further, by traversing the upper first electrode 5 in the direction perpendicular to the magnetic field, that is, in the vertical direction in the drawing, and changing the distance Δh between the first and second electrodes 5, the position Δh
It is possible to measure the flow velocity V of the conductive current body 2 at each time.

As mentioned above, the current velocity measuring device for a conductive current according to this embodiment can also accurately measure the precise flow velocity near the boundary layer in the flow path and the detailed flow velocity in the shear layer part of the jet section. This can greatly contribute to elucidating the structure of the flow in the conductive current body 2.

On the other hand, in each of the above embodiments, the case where the flow velocity of the conductive current body 2 is measured has been described, but when measuring the flow velocity distribution of the conductive current body 2, each of the embodiments may be configured as follows. .

First, FIG. 4(a) shows an example configuration for measuring the flow velocity distribution of a conductive current corresponding to FIGS. 1(a) to (c). ) are given the same reference numerals, and their explanation will be omitted, and only the different parts will be described here.

In FIG. 4(a), 9 is the first. A position detector consisting of a differential transformer or the like detects the position (y) of the second electrode 5;
-Y recorder. That is, the output signal (potential difference E) from the potentiometer 8 is input to the X-axis terminal of the X-Y recorder 10, and the output signal (position signal y) from the position detector 9 is input to the Y terminal of the X-Y recorder 10. It is configured to input to the shaft terminal.

In such a configuration, each output signal from the potentiometer 8 and the position detector 9 is transmitted as shown in FIG. As shown in (b), it is drawn on the X-Y recorder 10, and in this way, a flow velocity distribution diagram of the conductive current body 2 in the liquid depth direction of the channel forming member 1 is obtained.

Furthermore, FIG. 5(a) shows an example configuration for measuring the flow velocity distribution of a conductive current corresponding to the above-mentioned FIGS. 3(a) to (c). ) are given the same reference numerals, and their explanation will be omitted, and only the different parts will be described here.

In FIG. 5(a), 11 is the upper first electrode 5.
A position detector 12 is, for example, an X-Y recorder for drawing the flow velocity distribution of the conductive current body 2. That is, the output signal from the potentiometer 8 (potential difference E between the upper first electrode 5, which is a moving electrode, and the lower second electrode 5, which is a fixed electrode) is expressed as
The output signal is input to the X-axis terminal of the -Y recorder 12, and the output signal (position signal y) from the position detector 11 is input to the Y-axis terminal of the X-Y recorder 12.

In this configuration, by traversing the upper first electrode 5 in a direction perpendicular to the magnetic field, that is, in the vertical direction in the drawing, each output signal from the potentiometer 8 and the position detector 11 is changed as shown in FIG. 5(b). are drawn on the X-Y recorder 12. This FIG. 5 (1)) shows the relationship between the output signal from the potentiometer 8 and the output signal from the position detector 11, which is E = B f: v dv - -< The relationship 3 > is displayed. Therefore, dE/dy
That is, the gradient becomes proportional to the flow velocity V. In this way, a flow velocity distribution diagram of the conductive current body 2 in the liquid depth direction of the channel forming member 1 is obtained according to a change in the separation distance Δh.

In addition, the present invention can be modified and implemented in various ways without changing the gist thereof.

[Effects of the Invention] As described above, according to the present invention, there is provided a duct that constitutes a flow path for a conductive current whose flow velocity is to be measured.

A magnet is placed on the outside of a channel-constituting member such as a pipe, the whole is covered with a magnetic field, and a first and a second electrode are spaced apart along the insertion direction into the channel-constituting member from a direction perpendicular to the magnetic field. and at least one of the electrodes is movable along the insertion direction. Since the flow velocity of the conductive current is measured by detecting the potential difference between each of the second N electrodes, it is an extremely reliable flow velocity measurement device for a conductive current that can accurately measure the flow velocity of the conductive current. can be provided.

[Brief explanation of drawings]

FIGS. 1(a) to 1(C) are block diagrams showing one embodiment of the current velocity measuring device for a conductive fluid according to the present invention, and FIG. 1(a) is a front view of the current velocity measuring device for a conductive fluid; FIG. 1(b) is a sectional view showing details of the measurement unit, FIG. 1(C) is a sectional view showing details of the NFi for potential difference measurement, and FIG. 2 is a principle diagram for explaining the operation of the same embodiment. , FIGS. 3(a) to 3(C) are block diagrams showing other embodiments of the current measuring device for conductive current according to the present invention, and FIG. 3(C) is a sectional view showing details of the potentiometric electrode. , FIGS. 4(a) and (b) are a configuration diagram and a flow velocity distribution diagram showing another embodiment of the present invention, and FIGS. 5(a) and (b) are a configuration showing another embodiment of the present invention. FIG. 2 is a diagram and a flow velocity distribution diagram. DESCRIPTION OF SYMBOLS 1... Channel constituting member, 2... Conductive body, 3... Magnet, 4... Electrode holder, 5... Electrode, 6a, 6b.
... Seal sliding device, 7... Lead wire, 8... Potentiometer, 9... Position detector, 10... X-Y recorder, 11... Position detector, 12... X-Y recorder. Applicant Sub-Agent Patent Attorney Takehiko Suzue Figure 1 (a) Figure 1 (b) Figure 1 (c) Figure 211A Figure 3 (b) Figure 4 (a) Ichimyo (Lx 41m ( b) Figure 5 (a) One stroke speed-X Figure 5 (b)

Claims (1)

[Claims] A magnet is placed on the outside of a flow path component such as a duct or pipe that constitutes the flow path of a conductive current whose flow velocity is to be measured, and the whole is covered with a magnetic field. The electrodes are inserted into the channel forming member in a state where they are spaced apart along the insertion direction, and at least one electrode is movable along the insertion direction, and the potential difference between the first and second electrodes is reduced. 1. A flow velocity measuring device for a conductive current, characterized in that the flow velocity is measured by detection.