JPS62160066A - Annular magnetic field type electromagnetic fluid apparatus - Google Patents

Abstract

PURPOSE:To simplify the structure and to enhance the efficiency of an annular magnetic field type electromagnetic fluid apparatus by forming a closed loop-like magnetic field in a conductive fluid, and employing the closed magnetic field as an external magnetic field generator of an electrode fluid apparatus. CONSTITUTION:A toroidal coil 24 is bundled at upper and lower ends of annular passage. The outside for connecting the annular passage of the inside for connecting with a generator side header 36 with a generator side passage 3 and a pump side header 35 is used as a pump side passage 2. An external magnetic field 20 exists circumferentially in the passages 2, 3 by the coil 24. Conductive fluid in the passage 2 undergoes a downward force to flow, and the conductive fluid in the passage 3 an upward force to flow.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to electromagnetic fluid equipment such as electromagnetic pumps and electromagnetic flow couplers that drive conductive fluids such as fluid metals.

[Conventional technology]

In an electromagnetic flow coupler, two adjacent channels are arranged perpendicularly to a parallel magnetic field, and a conductive fluid such as liquid sodium is forced to flow through one of the channels to generate an electric current. In other words, it functions as a generator. The other channel functions as a pump by driving the conductive fluid using this induced current and magnetic field. In the following description, the former will be referred to as a generator-side flow path, and the latter will be referred to as a pump-side flow path.

In the conventional device, as described in JP-A-59-10163 (see Fig. 3), the central part of a rectangular duct is divided into upper and lower parts by a partition wall 1 made of a good conductor, and the upper part is connected to a pump side flow path 2. , the lower part is used as the generator side flow path 3. Magnets 4.5 are arranged so as to sandwich the flow channel from the left and right sides, and a parallel magnetic field is created within the flow channel.

The outer periphery of the flow path is electrically shortened using an electrode 6,
The current (driving current) generated in the generator side flow path 3 passes through the pump side flow path and then returns to the generator side flow path 3 through an external circuit. An insulating material 7 is lined on the sides of both the upper and lower flow path valves to prevent leakage of drive current.

The operating principle of this rectangular channel type electromagnetic flow coupler will be explained with reference to FIGS. 3 and 4. The conductive fluid in the generator-side flow path 3 in FIG. 3 is forced to flow in a direction perpendicular to the page from the back to the front by an external force. In this way, when a conductor is moved perpendicular to the magnetic field, an electromotive force is induced in the conductor according to Fleming's right-hand rule, and a current is generated. The direction of the current is perpendicular to both the magnetic field and the direction of motion, as shown in FIG. In the case of the flow coupler shown in FIG. 3, the direction is from the bottom of the figure to the top. The current generated in the generator-side flow path 3 in this manner flows into the pump-side flow path 2 through the central partition wall 1. In the pump-side flow path 2, a current flows in a magnetic field, and a pumping force is generated. This phenomenon is known as Fleming's left hand rule. The direction of the force is perpendicular to both the magnetic field and the current; 1) as shown in FIG. In Figure 3,
The paper is oriented directly from the front to the back. The fluid is driven by this force6, that is, by simply flowing fluid from one side, the other fluid can be driven without using a mechanical drive mechanism such as a piston or impeller.

Consider using an electromagnetic flow coupler having the above-mentioned characteristics in a tank-type fast breeder reactor shown in FIG. Fifth
As shown in the figure, in a tank-type fast reactor, heat generated in a reactor core 8 is transported to an intermediate heat exchanger 9 by liquid sodium driven by a pump 10. The generated heat is transported to the secondary sodium system by the same heat exchanger 9. The sodium in the secondary system is driven by a pump 11 and flows into a steam generator 12.
Heat is exchanged with the water side of the steam generator 12. Steam generated by the steam generator 12 flows into the turbine and operates the generator. As shown in FIG. 6, an electromagnetic flow coupler 13 can be installed in the tank instead of the secondary pump 10, and sodium (conductive fluid) in the secondary system can be used as a driving source. As mentioned above, electromagnetic flow couplers have no moving parts such as impellers and are easy to maintain, and can improve the reliability and safety of tank-type fast reactors.

As a conventional device of a type different from the above-mentioned rectangular type, the document Nucl Energy, 198
1. Vol.

20, Feb,, Not p79-p90,
Some use circular ducts. In the case of this flow coupler, as shown in FIG. 7, the duct is divided into two in the circumferential direction by a partition wall 1 made of a good conductor. The upper channel in FIG. 7 is defined as the pump-side channel 2, and the lower channel is defined as the generator-side channel 3. The arrangement of magnetic poles is also completely different from the rectangular type. In this case, magnets 4 and 5 are provided at the center and outer periphery of the flow path in order to create a radial magnetic field. FIG. 7 shows the case from the inside to the outside of the flow path. The operating principle of this annular channel type flow coupler will be explained. Generator side flow path 3
The driving fluid is caused to flow perpendicularly to the paper plane of FIG. 7 in a direction from the back to the front by an external force. The magnetic field is radial but perpendicular to the direction of fluid motion. Therefore, an electromotive force is generated in the tangential direction on the circumference at each point on the flow path (Fleming's right-hand rule), and the current also points in the tangential direction on the circumference, so if all points on the flow path are connected, the electromotive force will be generated in the counterclockwise direction. It becomes a loop.

This current flows into the pump-side flow path 2 through the partition wall 1.

If the current remains in a loop, the current and magnetic field are perpendicular to each other, so a driving force is generated and the fluid is driven (Fleming's left-hand rule). The direction of the force is perpendicular to the plane of the paper in FIG. 7, and is from the front to the back. Although the principle is as described above, there is actually no factor on the pump side to keep the current in the loop. Therefore, the flow path is not divided into two parts as shown in FIG. 7, but is divided into several parts as shown in FIG. 8 to create a loop current.

Yet another type of device has been devised. This is as described in Japanese Patent Application No. 54-130723.

It uses fan-shaped permanent magnets. The structure of this device is shown in FIGS. 9 and 10. As shown in FIG. 9, a fan-shaped magnet 15 and a fan-shaped flow path 1 are placed in one large circular tube
6 are arranged alternately. Inside the fan-shaped flow path, circular tubes 17 with small diameters are arranged so as to be in contact with each other, and electrodes] 8 are attached to both ends of the circular tubes 17.

In the case of this device, the inside of the small circular tube 17 corresponds to the pump-side flow path, and the remaining portion serves as the generator-side flow path.

The operating principle of this fan-shaped flow path type electromagnetic flow coupler will be explained with reference to FIG. The driving fluid in the fan-shaped flow path 16 (on the generator side) is caused to flow from the back to the front perpendicular to the plane of the paper. The magnetic field is nearly parallel within the flow path and perpendicular to the direction of fluid motion. Therefore, an outward electromotive force is induced according to Fleming's right-hand rule, and current flows outward. When the current reaches the outer electrode, the current flows inward through the pump-side channel formed by the array of tubes 17. As a result, a driving force is generated in the fluid within the circular tube 17 according to Fleming's left-hand rule.

The direction of the force is perpendicular to the plane of the paper, from the back to the front. That is, the generator side fluid and the pump side fluid flow in the same direction.

[Problem that the invention seeks to solve]

In the development of fast breeder reactors, reducing construction costs is currently an urgent issue, and tank-type fast reactors require smaller tanks. For this reason, a promising idea is to provide an electrode flow coupler inside the tank that has not only a pump function but also a heat exchange function.

When considering installing an electromagnetic flow coupler around the reactor core in a tank, in the case of a rectangular channel type electromagnetic flow coupler, it is necessary to install a plurality of coupler units 13 as shown in FIG. 11. Therefore, compared to the case of the electromagnetic flow coupler 13 configured with an annular flow path shown in FIG. 12, there is a drawback that the tank is larger in order to secure the same flow path area.

One of the causes of reducing the efficiency of electromagnetic flow couplers is the braking effect of leakage magnetic flux. Consider the case where a magnetic field exists to the outside of the electromagnetic flow coupler 13 as shown in Fig. 136 Fig. 13 shows the pump side flow path 2 of a rectangular electromagnetic flow coupler in a plane parallel to the magnetic field and perpendicular to the drive current. A cut sectional view is shown. Since no driving current flows in the leakage magnetic flux portion outside the electromagnetic flow coupler 13, no driving force acts on the fluid in this portion. Since the conductive fluid flows under the driving force within the electromagnetic flow coupler 13, the leakage magnetic flux area at the entrance and exit functions as a generator according to Fleming's right-hand rule, and the fluid has a force in the opposite direction to the flow, that is, a braking force. will be working. Next, consider a case where the external magnetic field is ideally reduced to zero at both ends of the electromagnetic flow coupler 13, as shown in FIG. In reality, leakage magnetic flux always exists. FIG. 14 shows a cross-sectional view taken in a plane parallel to the drive current and perpendicular to the magnetic field.

As described above, an electromotive force is generated in the conductive fluid in the generator side flow path 3 according to Fleming's right-hand rule. On the other hand, a driving force is generated in the fluid in the pump side flow path 2 according to the left-hand rule, but the flow due to this driving force interacts with an orthogonal external magnetic field and generates a back electromotive force according to the right-hand rule. become. In reality, the electromotive force on the pump side, the back electromotive force on the generator side, and the sum of the ohmic loss (1! current x resistance) in the fluid of the drive current are balanced. If you look at it from another perspective, this back electromotive force acts as electrical resistance, and there is no magnetic field at both ends of the coupler, so there is no back electromotive force, and the drive current from the pump side flows through this part. This bypass current at both ends of the flow path 2 does not contribute to driving the fluid and becomes a loss because there is no magnetic field.

As described above, in order to increase the efficiency of an electromagnetic flow coupler, it is essential to devise a way to attenuate the magnetic flux density at both ends to offset the above-mentioned braking effect and current bypass effect (together referred to as the termination effect). be. When manufacturing electromagnetic flow couplers, it is one of the extremely difficult techniques to optimize the leakage magnetic flux distribution by adjusting the magnet shape or its configuration. On the other hand, in order to increase the driving flow rate and driving pressure (pump head) of the electromagnetic flow coupler, it is necessary to have a long uniform magnetic field in the direction of the flow path. Therefore, in order to improve the performance of an electromagnetic flow coupler, it is necessary to reduce the termination effect and to continue applying a magnetic field in the flow direction for a long time using a single stage of magnets instead of multiple stages.

The magnets (both permanent magnets and electromagnetic) of the annular channel type electromagnetic flow coupler described as the second conventional example are as follows.

A radial magnetic field is applied to the annular flow path in the arrangement shown in FIG. As can be seen from the figure, the magnets 4 and 5 and the ferromagnetic material 22
A magnetic circuit is constructed by forming a radial magnetic field in the pump-side flow path 2 and the generator-side flow path 3.

Therefore, the magnetic field is directed inward in the radial direction on the N pole 4 side and outward in the S pole 5 side. Therefore, the drive current 21 is A-
It flows counterclockwise at the A' cross section (see Figure 16) and clockwise at the B-B' cross section (see Figure 17). For this reason, in the annular type, not only the magnetic structure (separating the N and S poles), but also the
In order to make the generated drive currents independent, it is necessary to separate the north and south poles, and it is necessary to correct the termination effect at both ends of each magnetic pole. Furthermore, in order to increase the length over which the magnetic field acts in the flow direction in the annular type, a multi-stage magnet configuration is required as shown in FIG. 18, and it is necessary to correct the terminal effect at each stage.

The third conventional example has an annular structure, which allows compact arrangement around the core. However, since the magnet is placed inside the flow path, the flow path area of the conductive fluid is limited;
The major problems are expected to be that the structure is complicated.

An object of the present invention is to provide a magnetic fluidic device with a simple structure and high efficiency, and in particular, to provide a simple structure with an annular structure that can contribute to downsizing of tank-type fast reactors. It's about doing.

[Means for solving problems]

The above problem can be solved by creating a closed-loop magnetic field in a conductive fluid using a solenoid coil or toroidal coil, and employing this closed magnetic field as an external magnetic field generator for an electrode-fluid device. For example, consider extending the flow path of a rectangular flow path type electromagnetic flow coupler in the direction of the magnetic field 20 to form an annular shape, as shown in FIGS. 3, 19, and 20. The magnetic field 20 needs to be a circularly closed magnetic field as shown in FIG. A circularly closed magnetic field can be realized by a toroidal coil or a solenoid coil as shown in FIG. 21, FIG. 22, and FIG. 23.

[Effect]

FIG. 24 shows the magnetic field 2o generated by the circular flow 21.

As shown in FIG. 25, the solenoid coil that has a circular flow 21 generates a linear magnetic field within the coil.6 Therefore, if the solenoid coils are arranged on the circumference as shown in FIG. A closed magnetic field 20 can be created. Instead of a solenoid coil, a continuous toroidal coil can also be used to create a closed magnetic field. Furthermore, if we consider that the circular current shown in FIG. 26 is created in an elliptical shape in the vertical direction, it will be understood that the closed magnetic field 20 can easily secure the necessary length in the axial direction.

〔Example〕

A first embodiment of the present invention will be explained with reference to FIG. 27. Second
As shown in Figure 7, the toroidal coil 24 is connected to the annular flow path 23
Tie at the top and bottom edges. It serves as an inlet or an outlet 25 for conductive fluid. As shown in FIG. 1, the inner annular flow path that communicates with the generator side header 36 is called the generator side flow path 3, and the outer side that communicates with the rudder 35 toward the pump side is called the pump side flow path 2. Each head 35, 36 is also provided under each flow path 2, 3 and has a similar communication relationship. As shown in the AA' cross-sectional view (see FIG. 2), an external magnetic field 20 exists in the flow path in the circumferential direction due to the toroidal coil (winding 24). Therefore, when the conductive fluid in the generator side flow path 3 is caused to flow from bottom to top by an external force, an outward electromotive force is generated according to Fleming's right-hand rule. As shown in FIG. 2, the electric current 21 generated in the generator side flow path 3 passes through the good conductor partition wall 1, flows through the conductive fluid in the pump side flow path 2, and flows upward or downward at the outer flow path wall. It flows downward, passes through the upper and lower ends, and is returned to the conductive fluid in the generator-side flow path from the inner flow path wall. Therefore, the conductive fluid in the pump-side flow path 2 flows under a downward force according to Fleming's left-hand rule. Figure 21 or 2
As shown in FIG. 3, according to the present invention, it is possible to ensure the required length of the external magnetic field in the direction of the flow path by simply increasing the length of the winding, and a multi-stage configuration is not required. Also.

Although the present invention is not limited to annular flow paths, when applied to a tank-type fast reactor due to the annular flow path configuration, it greatly contributes to miniaturization of the tank.

Furthermore, it goes without saying that the configuration is simple.

A second embodiment of the present invention will be explained with reference to FIG. In this embodiment, the -heavy annular flow path is divided into two by an insulating material partition 26 to form a generator side flow path 3 and a pump side flow path 2. As shown in the AA' cross-sectional view of the figure (see FIG. 29), a circumferential clockwise magnetic field 20 is created by the toroidal coil 24. The conductive fluid in the generator side flow path 3 is moved from bottom to top.
Figure 9: The material is caused to flow in the direction from a vertical tool to the surface of the paper by an external force.

According to Fleming's right-hand rule, a radially outward current flows in the conductive fluid in the generator-side flow path 3, and the current flows back through the conductive fluid in the pump-side flow path 2 where no electromotive force is generated. A closed circuit passing through the annular flow channel outer tube wall is constructed. The conductive fluid flows in the pump-side flow path 2.

The current interacts with orthogonal circumferential magnetic fields and, according to Fleming's left-hand rule, creates an upward driving force on the conductive fluid, acting as an electromagnetic flow coupler. This embodiment can provide an annular electromagnetic flow coupler with a relatively simple flow path configuration.

A third embodiment of the present invention will be described with reference to FIGS. 30 and 31. This embodiment realizes a circumferential magnetic field by using a solenoid coil 24 instead of the toroidal coil of the first embodiment, and operates in the same manner. According to this embodiment, an annular electromagnetic flow coupler can be realized with a relatively simple coil configuration.

A fourth embodiment of the present invention will be described with reference to FIGS. 32 and 33. This embodiment uses a solenoid coil 24 instead of the toroidal coil of the second embodiment to realize a magnetic field in the shape of one circumference, and has the same function. According to this embodiment,
Both the flow path and the coil can be realized with a simple configuration.

A fifth embodiment of the present invention will be described with reference to FIGS. 34 and 35. In this embodiment, the present invention is applied to a DC type electromagnetic pump. The annular channel wall 29 is made of a good conductor, a DC power source is connected between the inner and outer tube walls, and a radially outward current is electrically applied to the conductive fluid in the annular channel from the outside. . Due to the circumferentially clockwise magnetic field 20 and the outward current 21 created by the solenoid coil 24, a downward driving force is generated in the conductive fluid according to Fleming's left-hand rule, and it operates as an electromagnetic pump. According to this embodiment, an annular electromagnetic pump with less termination effect can be provided.

A sixth embodiment of the present invention will be described with reference to FIGS. 36 and 37. This embodiment combines the second embodiment, which has a pump function, with a heat exchange function.

The annular flow path provided with a closed magnetic field in the circumferential direction by a solenoid or toroidal coil is divided into multiple parts as shown in FIG. 36 to increase the contact area of the conductive fluid on the pump side and the generator side through the partition wall.

If there is a temperature difference between the conductive fluid on the pump side and the generator side,
Heat is transported from the high temperature side to the low temperature side and functions as a heat exchanger. According to this embodiment, an annular electromagnetic flow coupler having a heat exchanger and a pump function can be realized.

A seventh embodiment of the present invention will be described with reference to FIG. The nuclear reactor core 8 of the tank-type fast breeder reactor is isolated from the tank side by a cylindrical container 32 and a fluid stop 34 during steady operation. The liquid sodium in the tank is kept at a low temperature.

The heat exchange type annular electromagnetic flow coupler 31 circulates the sodium on the core side and transports the heat generated in the core 8 to the secondary sodium system. When the flow of secondary sodium stops, the sodium in the tank flows through the fluid stop 34, removes heat from the core, and radiates the heat through the outer wall of the tank. According to this embodiment, there is an advantage that the magnet of the electromagnetic flow coupler can be maintained in a low-temperature environment, and the electromagnetic flow coupler that integrates the pump and the heat exchanger can realize miniaturization of the tank and cost reduction. FIG. 39 shows the results of trial calculations for reducing the size of the tank when a heat exchange type electromagnetic flow coupler is applied to the currently designed tank type blast furnace (tank diameter: approximately 20 m). From the viewpoint of securing the primary sodium flow rate, the size of the electromagnetic flow coupler depends on the flow velocity, and as can be seen from the figure, it is possible to downsize the tank to just under 14 m at a flow velocity of 4 m/s.

FIG. 40 shows the pump efficiency evaluation results of the electromagnetic flow coupler using the number of stages N of magnets as a parameter. The horizontal axis corresponds to the strength of the magnetic field in the analysis results when the total length of the excitation part is kept constant. From the figure, it can be seen that the smaller the number of stages, the smaller the influence of the terminal effect, and the better the efficiency.

〔Effect of the invention〕

According to the present invention, since the length of the magnetic field in the direction of the flow path can be set arbitrarily, the influence of the terminal effect is smaller than when using multi-stage magnets, and the electromagnetic flow coupler and electromagnetic pump, etc. We can provide fluid equipment. Furthermore, when considering application to a tank-type fast breeder reactor, the annular structure can be used, which greatly contributes to the miniaturization of the tank, resulting in a significant cost reduction.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram of an embodiment of the present invention, Fig. 2 is a sectional view taken along line AA' in Fig. 1, Fig. 3 is an explanatory diagram of conventional example 1, and Fig. 4 is a principle diagram of an electromagnetic flow coupler. , Fig. 5 is a system diagram of a conventional fast reactor, Fig. 6 is a system diagram when an electromagnetic flow coupler is applied to a fast reactor, Figs. 7 and 8 are explanatory diagrams of conventional example 2, and Figs. Fig. 10 is an explanatory diagram of conventional example 3, Figs. 11 and 12 are examples of application of electromagnetic flow couplers to fast reactors, and Fig. 13 is an explanatory diagram of conventional example 3.
Figures 14 and 14 are explanatory diagrams of the terminal effect, Figures 15 and 16.
17 and 18 are explanatory diagrams showing that the magnetic field of Conventional Example 2 becomes multistage, and FIGS. 19 and 20 are explanatory diagrams of how the magnetic field is deformed, and FIGS. 21 and 22. Figure 23, 2nd
4, 25 and 26 are explanatory diagrams of toroidal coils and solenoid coils, FIG. 27 is an explanatory diagram of Embodiment 1, FIG. 28 is an explanatory diagram of Embodiment 2, and FIG. 29 is an explanatory diagram of Embodiment 2. A-A' sectional view, Figure 30 is an explanatory diagram of Example 3, Figure 31
30 is an axial sectional view of FIG. 30, FIG. 32 is an explanatory view of Embodiment 4, FIG. 33 is a BB' sectional view of FIG. 32, FIG. 34 is an explanatory view of Embodiment 5, and 35 The figure is a radial cross-sectional view of FIG. 34, FIGS. 36 and 37 are explanatory diagrams of Example 6, and FIG.
FIG. 39 is a detailed explanatory graph of the present invention, and FIG. 40 is a graph of the relationship between the pump efficiency and magnetic flux density of the electromagnetic flow coupler for each number of magnet stages. DESCRIPTION OF SYMBOLS 1... Good conductor (electrically conductive) partition, 2... Pump side flow path, 3... Generator side flow path, 13... Electromagnetic flow coupler, 20... Magnetic field, 21... Current, 24... Winding wire,
26... Insulating material partition, 28... DC power supply circuit.

Claims (1)

[Scope of Claims] 1. In a magnetic fluid device that applies a magnetic field to a conductive fluid passed through a flow path having an annular cross section to apply a flow force to the conductive fluid, a closed loop is formed within the annular cross section of the flow path. An annular magnetic field type magnetic fluid device characterized by being equipped with a magnetic field generating device arranged to generate a magnetic field. 2. In claim 1, the coil of the magnetic field generator is wound around the outer periphery of the flow path so that the wire length direction is along the flow of the conductive fluid. Magnetic field type magnetic fluid equipment. 3. An annular magnetic field electromagnetic fluid device according to claim 1, wherein the flow path has a multi-cylindrical shape including conductive separation walls that divide the flow path in the radial direction. 4. An annular magnetic field type electromagnetic fluid device according to claim 1, wherein the flow path is provided with an insulating material separation wall that divides the flow path in an annular circumferential direction. 5. In claim 1 or 2, the electromagnetic fluid device is a magnet fluid device including a power supply circuit that applies a potential between one side wall and the other side wall of a flow path. An annular magnetic field type magnetic fluid device characterized by: