JP6474217B2 - Magnetic fluid power generator - Google Patents

Description

  The present invention relates to a magnetic fluid power generation apparatus including a drive unit that applies a magnetic field to a magnetic fluid sealed in a circulation flow path and heats the magnetic fluid to drive circulation.

  Conventionally, MHD (Magneto-Hydro-Dynamics) power generation using Faraday's law of electromagnetic induction is known. In MHD power generation, a working fluid (plasma or liquid metal) having electrical conductivity is caused to flow through a generator flow path to which a magnetic field is applied from the outside, and voltage and current induced based on Faraday's law of electromagnetic induction The enthalpy of the working fluid is converted into electrical energy.

  However, in conventional MHD power generation, since plasma or liquid metal is used as a working fluid, a high operating environment (for example, about 2000 to 3000 ° C.) is unavoidable. Further, there is a problem that the generator becomes large in order to reduce the heat loss of the power generator. In addition, since liquid metals contain a lot of toxic substances such as mercury, there is a problem in terms of safety. Furthermore, in order to circulate the working fluid in the generator flow path, it is necessary to apply a driving force to the working fluid from the outside by a compressor, a compressor, or the like.

  On the other hand, a heating unit and a magnetic field application unit are provided in a circulation flow path in which a magnetic fluid is sealed, and the magnetization of the magnetic fluid heated by the heating unit is lowered to reduce the imbalance of the magnetic volume force acting on the magnetic fluid. A magnetic fluid driving device that uses a magnetic fluid to drive it is disclosed (see Patent Document 1).

JP, 2014-50140, A

  However, the apparatus disclosed in Patent Document 1 does not require an external power source to be applied to the electromagnet for driving the magnetic fluid, but does not specifically disclose the power generation method.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a magnetic fluid power generation apparatus capable of generating power with a simple configuration in a room temperature environment.

  A magnetic fluid power generation apparatus according to the present invention is configured to circulate a magnetic fluid and to apply a magnetic field to the magnetic fluid interposed in the circulation flow channel and enclosed in the circulation flow channel and to heat the magnetic fluid. A magnetic fluid power generation apparatus including a drive unit that circulates and drives, wherein the magnetic fluid has electrical conductivity and includes a power generation unit interposed in the circulation flow path. A magnetic field is applied in a substantially vertical direction to the power generation side circulation flow path having a rectangular cross-sectional shape, which is in communication with the road and surrounded by two sets of road walls facing each other over a predetermined length. A magnetic field application unit and an electrode plate provided on each of the other opposite road walls are provided, and power is output through the electrode plate.

  In the present invention, the drive unit applies a magnetic field to the magnetic fluid sealed in the circulation flow path and heats the magnetic fluid to drive the magnetic fluid in the circulation flow path. The drive unit reduces the magnetization of the heated magnetic fluid, and drives the magnetic fluid using an imbalance of the magnetic volume force acting on the magnetic fluid. The magnetic fluid has a relatively large magnetization in the normal temperature range, and the magnetization decreases when the temperature increases toward the Curie temperature (for example, about 200 ° C.). In addition, as a heat source in the drive unit, heat generated by a CPU or LSI of an electronic device or the like can be used (utilization of waste heat). Therefore, it is possible to circulate the magnetic fluid in the circulation flow path under a normal temperature environment.

The magnetic fluid has conductivity, and a power generation unit is interposed in the circulation channel. The power generation unit communicates with the circulation flow path and is surrounded by two sets of road walls facing each other over a predetermined length. One of the two sets of road walls and the power generation side circulation flow path having a rectangular cross-sectional shape A magnetic field application unit configured to apply a magnetic field in a direction substantially perpendicular to the wall; and an electrode plate provided on each of the other road walls. The rectangular cross-sectional shape is, for example, a square or a rectangle. For example, a permanent magnet (magnet) can be used for the magnetic field application unit. If the magnetic flux density of the magnetic field is B, the velocity of the magnetic fluid is u, and the dimension between the electrode plates is d, the voltage V ₀ generated between the electrode plates can be expressed as V ₀ = u · B · d. Thereby, it is possible to generate power with a simple configuration in a room temperature environment.

  In the magnetic fluid power generation device according to the present invention, the magnetic fluid has a conductivity of 1 S / m or more.

  In the present invention, the magnetic fluid has a conductivity of 1 S / m or more. For example, water, hydrocarbon oil, fluorine oil, or the like can be used as the mother fluid of the magnetic fluid. The conductivity of the water-based magnetic fluid is about 1-2 at 20 ° C., and the conductivity tends to increase with increasing temperature, for example, about 2-5 at 80 ° C. By setting the conductivity of the magnetic fluid to 1 S / m or more, a water-based magnetic fluid can be used.

  The magnetic fluid power generation device according to the present invention is characterized in that the total cross-sectional area of the power generation-side circulation flow path is smaller than the total cross-sectional area of the circulation flow path in which the drive unit is interposed.

  In the present invention, the total cross-sectional area of the power generation-side circulation channel is smaller than the total cross-sectional area of the circulation channel in which the drive unit is interposed. For example, a plurality of circulation channels provided with a drive unit are provided. In other words, the drive unit is provided with a plurality of circulation channels. Then, the circulation channels are joined at the junction so that the number of power generation-side circulation channels is smaller than the number of circulation channels. For example, when the drive unit is provided with four circulation channels, and the power generation unit is provided with two power generation side circulation channels, the junction unit has four channels on the upstream side of the power generation side circulation channel. Are merged into two flow paths. In addition, two flow paths branch into four flow paths on the downstream side of the power generation side circulation flow path. If the flow velocity of the magnetic fluid driven by the drive unit is u and the flow channel cross-sectional areas of the circulation channel and the power generation side circulation channel are the same, the flow rate (volume flow rate) Q is constant. The flow velocity of the magnetic fluid in the inside is approximately doubled. As a result, the voltage generated between the electrode plates can be doubled, and the power is proportional to the square of the voltage, so the power output from the electrode plates can be quadrupled and the output power can be increased. Can do.

  In addition, the number of circulation channels in which the drive unit is interposed is equal to the number of power generation side circulation channels, and the sectional area of each power generation side circulation channel is smaller than the sectional area of each circulation channel. It can also be done. Furthermore, the number of the power generation side circulation channels is made smaller than the number of the circulation channels in which the drive unit is interposed, and the cross sectional area of each power generation side circulation channel is made smaller than the cross sectional area of each circulation channel. It can also be configured.

  In the ferrofluid power generation device according to the present invention, the magnetic field application unit includes a pair of magnets provided on each of the one road walls and surrounded by a yoke, and one of the pair of magnets is A surface of the road wall that is magnetized in a direction substantially perpendicular to the road wall and directed toward the road wall, and is opposed to the first magnet having a width wider than the road wall and the first magnet therebetween. And a pair of second magnets magnetized in the direction of the first magnet, and the other of the pair of magnets is substantially perpendicular to the road wall and the road wall The third magnet is magnetized in the direction opposite to the direction toward the surface and is wider than the road wall. The third magnet is opposed to the third magnet, and is substantially parallel to the surface of the road wall. It has a set of 4th magnets magnetized in the direction opposite to the direction.

  In the present invention, the magnetic field application unit has a pair of magnets that are provided on each of the road walls and surrounded by a yoke. That is, the power generation side circulation channel is disposed between the pair of magnets. The pair of magnets applies a magnetic field in a direction substantially perpendicular to one road wall (that is, a direction substantially horizontal to the other road wall). The flow direction (magnetic fluid flow direction) of the power generation-side circulation flow path is the x axis, the direction substantially perpendicular to one road wall (ie, the magnetic field direction) is the y axis, and the other road wall is substantially the same. The vertical direction (that is, the direction substantially perpendicular to the electrode plate) is taken as the z-axis.

  One of the pair of magnets is magnetized in a direction substantially perpendicular to the one road wall and directed toward the road wall, and the first magnet wider than the road wall is interposed between the first magnet and the first magnet. And a pair of second magnets that are magnetized in the direction of the first magnet and are substantially parallel to the surface of the road wall. The other of the pair of magnets is magnetized in a direction substantially perpendicular to the one road wall and opposite to the direction toward the road wall, and has a third magnet wider than the road wall, and a third magnet. A pair of fourth magnets which are opposed to each other with a magnet therebetween and are magnetized in a direction substantially parallel to the surface of the road wall and opposite to the direction of the third magnet.

  That is, the first magnet is wider than the width (z-axis direction dimension) of the wall of the power generation-side circulation flow path, and the magnetization direction (direction from the S pole to the N pole) is the y-axis direction. Head to the power generation side circulation channel. The second magnet is a pair of magnets that are opposed to each other with the first magnet interposed therebetween, and the direction of magnetization (the direction from the S pole to the N pole) is the z-axis direction toward the first magnet. The third magnet is wider than the width of the road wall of the power generation side circulation passage (dimension in the z-axis direction), the direction of magnetization (direction from the S pole to the N pole) is the y axis direction, and the power generation side The direction is opposite to the direction of the circulation channel. The fourth magnet is a pair of magnets facing each other with the third magnet interposed therebetween, and the direction of magnetization (direction from the S pole to the N pole) is the z-axis direction and is opposite to the direction of the third magnet. Head in the direction.

  The lines of magnetic force that have emerged from the N pole of the first magnet to the gap side go to one of the S poles of the third magnet through one wall of the power generation side circulation channel. Since a pair of fourth magnets are arranged with the third magnet in between, the magnetic field lines coming out of the third magnets go to each fourth magnet, pass through the yoke, and go to the second magnet. Since a pair of second magnets are arranged with the first magnet in between, the lines of magnetic force emitted from the second magnet go to the first magnet. That is, the magnetic field lines form a closed loop in the order of the first magnet, the road wall of the power generation side circulation flow path, the third magnet, the fourth magnet, the yoke, the second magnet, and the first magnet. Leakage of magnetic lines of force toward the three magnets can be reduced, and the magnetic flux density of the magnetic flux passing through one road wall of the power generation side circulation flow path can be increased. As a result, a magnetic field in a substantially vertical direction can be strengthened with respect to one road wall of the power generation side circulation flow path, and the output power can be increased.

  In the magnetic fluid power generation device according to the present invention, the ratio of the width of the second magnet to the width of the first magnet and the ratio of the width of the fourth magnet to the width of the third magnet are 0.5 or more. It is characterized by.

  In the present invention, the ratio p (= wb / wa) of the width wb (dimension in the z-axis direction) of the second magnet to the width wa (dimension in the z-axis direction) of the first magnet is 0.5 or more. is there. The ratio p (= wb / wa) of the width wb (dimension in the z-axis direction) of the fourth magnet to the width wa (dimension in the z-axis direction) of the third magnet is 0.5 or more. When the width wa of the first magnet and the third magnet is increased, among the magnetic lines of force from the first magnet to the third magnet, the magnetic lines passing through one road wall of the power generation side circulation channel are relatively reduced. The magnetic flux density of the magnetic flux passing through one road wall of the side circulation channel is reduced. Further, when the width wa of the first magnet and the third magnet is increased, the end portions in the z-axis direction of the first magnet and the third magnet are separated from one road wall of the power generation side circulation flow path, and the first magnet and the first magnet Since the power generation-side circulation flow path is located at the center of the three magnets in the z-axis direction, the lines of magnetic force (from the N pole of the first magnet to the S pole of the third magnet in and around the power generation-side circulation flow path ( The range in which the distribution in the z-axis direction of the magnetic flux density in the y-axis direction becomes uniform becomes large.

  Conversely, when the width wa of the first magnet and the third magnet is reduced, among the lines of magnetic force from the first magnet to the third magnet, the lines of magnetic force passing through one road wall of the power generation-side circulation flow path are relatively Therefore, the magnetic flux density of the magnetic flux passing through one road wall of the power generation side circulation flow path increases. Further, when the width wa of the first magnet and the third magnet is reduced, the end portions in the z-axis direction of the first magnet and the third magnet approach one road wall of the power generation side circulation flow path, and the first magnet and the third magnet Since the power generation side circulation flow path is positioned near the end of the three magnets in the z-axis direction, the magnetic field lines from the N pole of the first magnet to the S pole of the third magnet in the power generation side circulation flow path and the vicinity thereof. The range in which the distribution in the z-axis direction of (magnetic flux density in the y-axis direction) is uniform is reduced.

  That is, when the ratio p (= wb / wa) is less than 0.5, the width wa is relatively increased, the magnetic flux density is decreased, and the output power is decreased. By setting the ratio p (= wb / wa) to 0.5 or more, the y-axis direction component (y-axis direction magnetic flux density) of the magnetic flux density of the magnetic flux passing through one road wall of the power generation side circulation channel The uniformity of the distribution in the z-axis direction can be improved, the magnetic flux density can be increased, and the output power can be increased.

  The magnetic fluid power generation device according to the present invention is characterized in that a ratio of a thickness dimension of the magnet to a separation dimension of the pair of magnets is 3 or more.

  In the present invention, the ratio q (= t / d) of the magnet thickness dimension t (dimension in the y-axis direction) to the separation dimension d (gap dimension in the y direction) between the pair of magnets is 3 or more. is there. When the ratio q (= t / d) is less than 3, the separation dimension d is relatively increased, the magnetic flux density is decreased, and the output power is decreased. By setting the ratio q (= t / d) to 3 or more, the magnetic flux density can be increased and the output power can be increased.

  In the magnetic fluid power generation device according to the present invention, the pair of magnets are neodymium magnets having a residual magnetic flux density of 1.33 T or more.

  In the present invention, the pair of magnets are neodymium magnets having a residual magnetic flux density of 1.33 T or more. By using a neodymium magnet having a residual magnetic flux density of 1.33 T or more, the magnetic flux density can be increased.

  In the magnetic fluid power generation device according to the present invention, the magnetic flux density of the magnetic field applied by the magnetic field application unit is 1.0 T or more.

  In the present invention, the magnetic flux density of the magnetic field applied by the magnetic field application unit is 1.0 T or more. Since the output power is proportional to the square of the magnetic flux density, the required power can be obtained by setting the magnetic flux density to 1.0 T or more.

  According to the present invention, power can be generated with a simple configuration in a room temperature environment.

It is a schematic diagram which shows an example of a structure of the magnetic fluid electric power generating apparatus of 1st Embodiment. It is a schematic diagram which shows an example of a structure of the drive part of 1st Embodiment. It is an external appearance perspective view which shows the 1st Example of a structure of the electric power generation part of 1st Embodiment. It is a front view which shows the 1st Example of a structure of the electric power generation part of 1st Embodiment. It is a schematic diagram which shows an example of the magnetic force line applied by the electric power generation part of 1st Example. It is an external appearance perspective view which shows the 2nd Example of a structure of the electric power generation part of 1st Embodiment. It is a front view which shows the 2nd Example of a structure of the electric power generation part of 1st Embodiment. It is a schematic diagram which shows the calculation model of the electric power which the electric power generation part of 1st Embodiment generate | occur | produces. It is explanatory drawing which shows an example of the magnetic field analysis result in case the ratio p by the electric power generation part of 1st Example of 1st Embodiment is 0.5. It is explanatory drawing which shows an example of the magnetic field analysis result in case the ratio p by the electric power generation part of 1st Example of 1st Embodiment is 1.0. It is explanatory drawing which shows an example of the magnetic field analysis result in case the ratio p by the electric power generation part of 1st Example of 1st Embodiment is 1.5. It is explanatory drawing which shows an example of the magnetic field analysis result in case the ratio p by the electric power generation part of 1st Example of 1st Embodiment is 2.0. It is explanatory drawing which shows an example of the magnetic field analysis result in case the ratio p by the electric power generation part of 1st Example of 1st Embodiment is 3.0. It is explanatory drawing which shows an example of the magnetic field analysis result in case the ratio p by the electric power generation part of 2nd Example of 1st Embodiment is 1.0. It is explanatory drawing which shows an example of the magnetic field analysis result at the time of changing the thickness of the magnet by the electric power generation part of 1st Embodiment. It is a schematic diagram which shows an example of a structure of the magnetic fluid electric power generating apparatus of 2nd Embodiment. It is explanatory drawing which shows the numerical example of the electric power which a electric power generation part generate | occur | produces.

(First embodiment)
Hereinafter, the present invention will be described with reference to the drawings illustrating embodiments thereof. FIG. 1 is a schematic diagram showing an example of the configuration of a ferrofluid power generation device 100 according to the first embodiment. The magnetic fluid power generation apparatus 100 is interposed in the circulation channel 10 with a closed loop circulation channel 10, a drive unit 20 interposed at a required position of the circulation channel 10, and an appropriate distance from the drive unit 20. A power generation unit 30 is provided. The drive unit 20 includes a magnet 21, a heating unit 22, and the like. A magnetic fluid having electrical conductivity is enclosed in the circulation channel 10, and the magnetic fluid is driven by the drive unit 20 so as to circulate in the circulation channel 10 in the direction indicated by the arrow in FIG. is there.

  The magnetic fluid sealed in the circulation channel 10 may be a mixture of at least one solvent having a lower boiling point than the mother liquor in the mother liquor in which the magnetic fine particles are dispersed.

As magnetic fine particles of the magnetic fluid, for example, iron oxide-based fine particles, spinel ferrite (MFe ₂ O ₄ : M = Fe, Mn, Ni, MnZn), γ-hematite (γ-Fe ₂ O ₃ ), etc. are used. it can. Also as magnetic fine particles. The most preferable is manganese zinc ferrite (Mn _x Zn _1-x Fe ₂ O ₄ ), which has the largest magnetization in the normal temperature region and the highest temperature dependence of the magnetization. By controlling the composition, the Curie temperature And is most suitable as a component of a temperature-sensitive magnetic fluid. In addition, as the mother fluid of the magnetic fluid, for example, water, hydrocarbon-based oil (such as kerosene or alkylnaphthalene), or fluorine-based oil (such as purple olopolyether) can be used.

  As the low boiling point solvent, a solvent having a lower boiling point than that of the mother liquid of the magnetic fluid can be used. The kind of the low boiling point solvent is not particularly limited, and can be appropriately selected in consideration of compatibility with the mother liquor. The mixing ratio may be appropriately determined in consideration of various thermomagnetic properties. By boiling the magnetic fluid, the driving speed of the magnetic fluid can be increased due to a decrease in spatial magnetic susceptibility, a liquid exclusion effect, and the like, and as a result, the output voltage can be increased.

  The cross-sectional inner diameter of the circulation channel 10 can be set to about 5 mm, for example. The Reynolds number of the circulation channel 10 is most preferably 10,000 or less. For example, if the cross-sectional inner diameter of the circulation channel 10 is 5 mm or less, the magnetic fluid power generation device 100 can be miniaturized, and if the laminar flow has a Reynolds number of 10,000 or less, the flow in the circulation channel 10 can be reduced. It is possible to drive the magnetic fluid with high efficiency and less turbulence, less stagnation in the circulation flow path 10, and bubbles generated by heat are less likely to stay. Further, the amount of heat applied to the magnetic fluid can be reduced, and for example, the magnetic fluid can be circulated with high efficiency by using a small amount of waste heat.

  FIG. 2 is a schematic diagram illustrating an example of the configuration of the drive unit 20 according to the first embodiment. FIG. 2 also illustrates the magnetic field distribution and magnetic volume force in the flow path direction in the circulation flow path 10. As shown in FIG. 2, the drive unit 20 includes a magnetic field generation unit 21, a heating unit 22, and the like disposed around the circulation flow path 10. The magnetic field generation unit 21 includes a permanent magnet 211, a yoke 212, and the like.

  The magnetic field generation unit 21 includes two permanent magnets 211 having a magnetization easy axis perpendicular to the flow path direction of the circulation flow path 10 (the direction indicated by x in FIG. 2). They are arranged differently (different polar parallel arrangement).

  As the permanent magnet 211, for example, a neodymium magnet, a samarium cobalt magnet, a ferrite magnet, or the like can be used, but a neodymium magnet that has the largest magnetic force and can generate a high magnetic field is preferable. The most preferable material is a neodymium magnet having a high residual magnetic flux density Br, and a magnet material having Br = 1.33 T (Tesla) or more is desirable. The shape of the permanent magnet 211 may be any shape, but normally a prism, cylinder, or elliptic cylinder can be used.

  The heating unit 22 is arranged on one end side of the magnetic field generation unit 21 (downstream side of the circulation channel 10) so as to overlap with one permanent magnet 211 of the magnetic field generation unit 21. The heating unit 22 may be a heating element such as a heater, or may be configured to use waste heat from a heating component such as a CPU or LSI.

  Next, the circulation driving of the magnetic fluid by the driving unit 20 will be described. When a magnetic field H is applied to a magnetic fluid, it behaves as a fluid having magnetization M. Iron oxide fine particles, which are constituents of magnetic fluid, behave superparamagnetically at room temperature. Although the magnetization of a superparamagnetic material follows a Langevin function with respect to a magnetic field, it can be approximated that the magnetization is proportional to the magnetic field in a relatively low magnetic field region. Further, since the Curie temperature of the iron oxide fine particles is 477 K (204 ° C.), the magnetic fluid has a temperature-sensitive characteristic in which magnetization decreases toward the Curie temperature as the temperature rises. From the above, the magnetization M of the local magnetic fluid can be expressed by the equation (1).

Here, μ ₀ is the vacuum permeability, χ is the magnetic susceptibility, α is the porosity (void ratio: ratio of gas phase), and T (x) is the temperature of the magnetic fluid in the heating unit 22. , T ₀ is the temperature of the magnetic fluid in the non-heated part, and T _c is the Curie temperature of the magnetic fine particles.

  In addition, the magnetic volume force F expressed by the equation (2) acts on the magnetic fluid having the magnetization M. Here, ∇H is a magnetic field gradient (magnetic field gradient). Assuming that the magnetic field (magnetic field distribution) in the y-axis direction and the z-axis direction with respect to the x-axis direction that is the flow path direction of the circulation flow path 10 is uniform, the x-axis direction (magnetic fluid) in the circulation flow path 10 The magnetic volume force Fx acting in the direction of the flow of (3) can be expressed by the equation (3). Here, Hx is a magnetic field in the x-axis direction.

  The magnetic field distribution in the channel direction (x-axis direction) by the magnetic field generation unit 21 shown in FIG. 2 is as shown in the middle diagram of FIG. 2, and the magnetic volume force in the channel direction is as shown in the lower diagram of FIG. become.

  In the stage before heating, the sign of the magnetic body force F is reversed every time the sign of the magnetic field H and the sign of the magnetic field gradient ∇H are changed, as indicated by the curve (i) in the lower part of FIG. F6 is balanced and the magnetic fluid does not move.

  When the magnetic fluid is heated to a temperature below the boiling point TL of the low boiling point solvent in the heating unit 22, the magnetization M of the heating unit 22 decreases with respect to the magnetization M0 of the non-heating unit as the temperature T increases. As shown in the curve (ii) in the lower part of FIG. 2, the magnetic volume forces F4, F5, and F6 of the heating unit 22 are smaller than the magnetic volume forces F1, F2, and F3 of the non-heated unit that is not heated. Of the magnetic body force of the heating unit 22, F2 is in a negative direction, but is canceled because it has the same magnitude as F1, and the magnetic body force of F3 in the positive direction is substantially dominant. Thereby, the magnetic fluid moves spontaneously in the x-axis direction.

  Further, as shown in the curve (iii) in the lower part of FIG. 2, when the magnetic fluid is heated to the boiling point TL of the low boiling point solvent or more and lower than the boiling point TH of the mother fluid of the magnetic fluid, the temperature T increases and the boiling point of the low boiling point solvent is increased. When air bubbles are generated by the above, the porosity α increases, so the magnetization M of the heating unit 22 further decreases, and the magnetic volume force F that drives the magnetic fluid in the x-axis direction increases. Thus, for example, the magnetic fluid can be continuously circulated at a flow rate of about 40 mm / s.

  As described above, the drive unit 20 applies a magnetic field to the magnetic fluid sealed in the circulation flow path 10 and heats the magnetic fluid to circulate and drive the magnetic fluid in the circulation flow path 10. The drive unit 20 reduces the magnetization of the heated magnetic fluid, and drives the magnetic fluid using an imbalance of the magnetic volume force acting on the magnetic fluid. The magnetic fluid has a relatively large magnetization in the normal temperature range, and the magnetization decreases when the temperature increases toward the Curie temperature (for example, about 200 ° C.). In addition, as a heat source in the drive unit 20, heat generated by a CPU or LSI of an electronic device or the like can be used (utilization of waste heat). Therefore, the magnetic fluid in the circulation channel 10 can be circulated in a normal temperature environment.

  FIG. 3 is an external perspective view showing a first example of the configuration of the power generation unit 30 of the first embodiment, and FIG. 4 is a front view showing a first example of the configuration of the power generation unit 30 of the first embodiment. . As shown in FIG. 4, the power generation unit 30 communicates with the circulation channel 10 and is surrounded by two sets of road walls (11, 12, 13, 14) facing each other over a predetermined length, and has a rectangular cross-sectional shape. The magnetic field application section (31) that applies a magnetic field in a substantially vertical direction to one of the road walls (11, 12) of the power generation side circulation flow path 10a and the two sets of road walls (11, 12, 13, 14). , 32, 33, 34, 35) and electrode plates (15, 16) provided on the other road walls (13, 14), respectively. The rectangular cross-sectional shape is, for example, a square or a rectangle. For example, a permanent magnet (magnet) can be used for the magnetic field application unit.

  Next, the magnetic field application unit will be described. The magnetic field application unit has a pair of magnets (31, 32, 33, 34) provided on each of the road walls (11, 12). That is, the power generation side circulation flow path 10a is arranged between the pair of magnets (31, 32, 33, 34). The pair of magnets (31, 32, 33, 34) is substantially perpendicular to one road wall (11, 12) (that is, substantially horizontal to the other road wall (13, 14)). ) To apply a magnetic field. Around the pair of magnets (31, 32, 33, 34), a box-shaped yoke 35 having both surfaces opened is disposed. That is, the pair of magnets (31, 32, 33, 34) is surrounded by the yoke 35.

  Further, the flow direction (the direction in which the magnetic fluid flows) of the power generation side circulation flow channel 10a is the x axis, the direction substantially perpendicular to the one road wall (11, 12) (ie, the magnetic field direction) is the y axis, and the other A direction substantially perpendicular to the road walls (13, 14), that is, the electrode plates 15 and 16, is defined as the z-axis.

  As shown in FIG. 4, one of the pair of magnets (31, 32) is magnetized in a direction substantially perpendicular to the one road wall (11, 12) and toward the road wall. A pair of second magnets 32 that are opposed to each other with the first magnet 31 wider than the wall, and are magnetized in the direction of the first magnet 31 and are substantially parallel to the surface of the road wall. , 32.

  Further, the other (33, 34) of the pair of magnets is magnetized in a direction substantially perpendicular to the one road wall (11, 12) and in a direction opposite to the direction toward the road wall. Also, a pair of fourth magnets, which are opposed to each other with the wide third magnet 33 interposed therebetween and are magnetized in a direction substantially parallel to the surface of the road wall and opposite to the direction of the third magnet 33. 34.

  That is, the first magnet 31 is wider than the width (z-axis direction dimension) of the road walls (11, 12) of the power generation-side circulation flow path 10a, and the magnetization direction (direction from the S pole to the N pole). Is in the y-axis direction toward the power generation-side circulation flow path 10a. The second magnet 32 is a pair of magnets that are opposed to each other with the first magnet 31 in between, and the direction of magnetization (direction from the S pole to the N pole) is the z-axis direction. Head.

  The third magnet 33 is wider than the width (dimension in the z-axis direction) of the road walls (11, 12) of the power generation-side circulation flow path 10a, and the magnetization direction (direction from the S pole to the N pole) is y. The axial direction is in the direction opposite to the direction of the power generation side circulation passage 10a. The fourth magnet 34 is a pair of magnets that are opposed to each other with the third magnet 33 interposed therebetween, and the magnetization direction (direction from the S pole to the N pole) is the z-axis direction. Head in the opposite direction.

  Let L be the length of each of the pair of magnets (31, 32, 33, 34). The width of the first magnet 31 and the third magnet 33 is wa, and the width of the second magnet 32 and the fourth magnet 34 is wb. The dimension of the gap 36 between the pair of magnets (31, 32, 33, 34) is d, and the thickness of the pair of magnets (31, 32, 33, 34) is t. That is, for convenience, the x-axis direction is the magnet length direction, the y-axis direction is the magnet thickness direction, and the z-axis direction is the magnet width direction. In addition, if the cross-sectional shape of the power generation side circulation channel 10a is a square, the width of the road wall is approximately d.

  As the pair of magnets (31, 32, 33), for example, a neodymium magnet, a samarium cobalt magnet, a ferrite magnet, or the like can be used. A neodymium magnet having the largest magnetic force and capable of generating a high magnetic field. Is preferred.

  FIG. 5 is a schematic diagram showing an example of the lines of magnetic force applied by the power generation unit 30 of the first embodiment. As shown in FIG. 5, the magnetic lines of force that have emerged from the north pole of the first magnet 31 toward the gap 36 pass through one road wall (11, 12) of the power generation side circulation channel 10 a and the south pole of the third magnet 33. Head to. Since a pair of fourth magnets 34, 34 are arranged with the third magnet 33 in between, the magnetic field lines coming out of the third magnet 33 go to the fourth magnets 34, 34 and pass through the yoke 35. To the second magnet 32, 32. Since the pair of second magnets 32, 32 are arranged with the first magnet 31 in between, the magnetic field lines coming out of the second magnet 32 go to the first magnet 31.

  That is, the lines of magnetic force are closed loop in the order of the first magnet 31, the road walls (11, 12) of the power generation side circulation passage 10 a, the third magnet 33, the fourth magnet 34, the yoke 35, the second magnet 32, and the first magnet 31. The magnetic flux of the magnetic flux passing through one of the road walls (11, 12) of the power generation side circulation passage 10a can be reduced by reducing the leakage of the magnetic lines of force from the first magnet 31 to the third magnet 33. The density can be increased. Thereby, the magnetic field in a substantially vertical direction can be strengthened with respect to one of the road walls (11, 12) of the power generation-side circulation flow path 10a, and the output power can be increased.

  The cross section of the circulation flow path 10 is circular, and the cross section of the power generation side circulation flow path 10a is rectangular. However, if the cross sectional shape is changed at a position where the circulation flow path 10 and the power generation side circulation flow path 10a are connected to each other. Good. Further, the power generation-side circulation flow path 10a only needs to have a rectangular cross-sectional shape in a range (length) in which the electrode plates (15, 16) are opposed to each other.

  In the first embodiment described above, the power generation unit 30 is configured to include one power generation side circulation channel 10a, but the power generation side circulation channel 10a is not limited to one, and includes a plurality. It may be a configuration. Next, the structure provided with the two power generation side circulation flow paths 10a will be described.

  FIG. 6 is an external perspective view showing a second example of the configuration of the power generation unit 30 of the first embodiment, and FIG. 7 is a front view showing a second example of the configuration of the power generation unit 30 of the first embodiment. . As shown in FIGS. 6 and 7, a pair of magnets (31, 32, 33, 34) respectively provided on one of the road walls (11, 12) with respect to the upper power generation side circulation channel 10 a. ). That is, the power generation side circulation flow path 10a is arranged between the pair of magnets (31, 32, 33, 34).

  One of the pair of magnets (31, 32) is magnetized in a direction substantially perpendicular to the one road wall (11, 12) and toward the road wall, and has a first width wider than the road wall. A magnet 31 and a pair of second magnets 32 and 32 that are opposed to each other with the first magnet 31 therebetween and are substantially parallel to the surface of the road wall and magnetized in the direction of the first magnet 31 are provided.

  Further, the other (33, 34) of the pair of magnets is magnetized in a direction substantially perpendicular to the one road wall (11, 12) and in a direction opposite to the direction toward the road wall. Also, a pair of fourth magnets, which are opposed to each other with the wide third magnet 33 interposed therebetween and are magnetized in a direction substantially parallel to the surface of the road wall and opposite to the direction of the third magnet 33. 34.

  That is, the first magnet 31 is wider than the width (z-axis direction dimension) of the road walls (11, 12) of the power generation-side circulation flow path 10a, and the magnetization direction (direction from the S pole to the N pole). Is in the y-axis direction toward the power generation-side circulation flow path 10a. The second magnet 32 is a pair of magnets that are opposed to each other with the first magnet 31 in between, and the direction of magnetization (direction from the S pole to the N pole) is the z-axis direction. Head.

  The third magnet 33 is wider than the width (dimension in the z-axis direction) of the road walls (11, 12) of the power generation-side circulation flow path 10a, and the magnetization direction (direction from the S pole to the N pole) is y. The axial direction is in the direction opposite to the direction of the power generation side circulation passage 10a. The fourth magnet 34 is a pair of magnets that are opposed to each other with the third magnet 33 interposed therebetween, and the magnetization direction (direction from the S pole to the N pole) is the z-axis direction. Head in the opposite direction.

  In addition, the lower power generation side circulation channel 10b has a pair of magnets (31, 32, 33, 34) provided on one of the road walls (11, 12). That is, the power generation side circulation flow path 10b is disposed between the pair of magnets (31, 32, 33, 34). Since the arrangement of the first magnet 31, the second magnet 32, the third magnet 33, and the fourth magnet 34 is the same as that for the power generation side circulation flow path 10a, the description thereof is omitted. In addition, the 4th magnet 34 with respect to the electric power generation side circulation flow path 10a and the 2nd magnet 32 with respect to the electric power generation side circulation flow path 10b are shared. Moreover, the 2nd magnet 32 with respect to the electric power generation side circulation flow path 10a and the 4th magnet 34 with respect to the electric power generation side circulation flow path 10b are shared.

  With the above-described configuration, a magnetic field in the direction from the right side to the left side in the figure is applied to the power generation side circulation channel 10a, and a magnetic field in the direction from the left side to the right side is applied to the power generation side circulation channel 10b.

  Next, electric power generated in the power generation unit 30 will be described. FIG. 8 is a schematic diagram illustrating a calculation model of power generated by the power generation unit 30 according to the first embodiment. In FIG. 8, the pipe having a rectangular cross section indicates the power generation side circulation passage 10a. In addition, a magnetic field having a magnetic flux density B is applied in a direction substantially perpendicular to one of the road walls (11, 12) of the power generation side circulation channel 10a, and the other road wall (13, 14) The electrode plates (15, 16) having substantially the same dimensions as the road walls (13, 14) are provided. The length of the power generation side circulation channel 10a (electrode plates 15 and 16) is L, the width is w, and the gap is d. The flow direction (the direction in which the magnetic fluid flows) of the power generation-side circulation flow channel 10a is defined as the x axis, the gap direction is defined as the y axis, and the width direction is defined as the z axis. The direction of the magnetic field is the y-axis direction.

According to Faraday's law of electromagnetic induction, the open-circuit voltage V ₀ generated between the electrode plates 15 and 16 can be expressed by Expression (4). Thereby, it is possible to generate power with a simple configuration in a room temperature environment.

  Here, u is the velocity of the magnetic fluid having conductivity. Further, the electric resistance (internal resistance) r of the magnetic fluid passing between the electrode plates 15 and 16 can be expressed by Expression (5). Here, σ is the conductivity [S / m] of the magnetic fluid.

Further, when the external resistor R is connected between the electrode plates 15 and 16, the maximum output power is obtained when the internal resistance r and the external resistance R are equal. In this case, the output voltage _Vopt is And can be represented by the formula (6).

The maximum output power P _max when the output voltage is V _opt can be expressed by Equation (7). Further, the flow rate (volume flow rate) Q of the magnetic fluid flowing through the power generation side circulation flow path 10a can be expressed by the equation (8), and from the equations (4), (5), (7), (8) The output power P _max can be expressed by Expression (9).

  That is, in order to optimize (maximum) the electric power generated in the power generation unit 30, for example, the power generation side circulation flow path 10a is made of a magnetic fluid having a high conductivity that reduces the cross-sectional area of the power generation side circulation flow path 10a. It is conceivable to increase the length, increase the volume flow rate of the magnetic fluid flowing through the power generation side circulation passage 10a, or increase the magnetic flux density. Thereby, it is possible to generate power with a simple configuration in a room temperature environment.

  In the present embodiment, the magnetic fluid has a conductivity of 1 S / m or more. For example, water, hydrocarbon oil, fluorine oil, or the like can be used as the mother fluid of the magnetic fluid. The conductivity of the water-based magnetic fluid is about 1-2 at 20 ° C., and the conductivity tends to increase with increasing temperature, for example, about 2-5 at 80 ° C. By setting the conductivity of the magnetic fluid to 1 S / m or more, a water-based magnetic fluid can be used.

  Further, in the present embodiment, the ratio p (= wb / wa) of the width wb (dimension in the z-axis direction) of the second magnet 32 to the width wa (dimension in the z-axis direction) of the first magnet 31 is 0. 5 or more. The ratio p (= wb / wa) of the width wb (dimension in the z-axis direction) of the fourth magnet 34 to the width wa (dimension in the z-axis direction) of the third magnet 33 is 0.5 or more. When the width wa of the first magnet 31 and the third magnet 33 is increased, among the lines of magnetic force directed from the first magnet 31 to the third magnet 33, one of the road walls (11, 12) of the power generation side circulation channels 10 a, 10 b is used. Since the lines of magnetic force that pass through are relatively reduced, the magnetic flux density of the magnetic flux that passes through one of the road walls (11, 12) of the power generation-side circulation flow paths 10a, 10b is reduced. Further, when the width wa of the first magnet 31 and the third magnet 33 is increased, the end portions in the z-axis direction of the first magnet 31 and the third magnet 33 are separated from one road wall of the power generation side circulation channels 10a and 10b. Since the power generation side circulation flow paths 10a and 10b are located at the center of the first magnet 31 and the third magnet 33 in the z-axis direction, the first power generation side circulation flow paths 10a and 10b and the vicinity thereof The range in which the distribution in the z-axis direction of the lines of magnetic force (magnetic flux density in the y-axis direction) from the N pole of the magnet 31 to the S pole of the third magnet 33 becomes larger.

  Conversely, if the width wa of the first magnet 31 and the third magnet 33 is reduced, of the lines of magnetic force going from the first magnet 31 to the third magnet 33, one of the road walls of the power generation side circulation channels 10 a, 10 b ( 11 and 12), the magnetic field lines passing through the power generation side circulation passages 10a and 10b are relatively increased, so that the magnetic flux density of the magnetic flux passing through one of the road walls (11 and 12) is increased. Further, when the width wa of the first magnet 31 and the third magnet 33 is reduced, the end portions in the z-axis direction of the first magnet 31 and the third magnet 33 become one of the road walls of the power generation side circulation channels 10a and 10b ( 11, 12), and the power generation side circulation passages 10 a, 10 b are positioned near the ends of the first magnet 31 and the third magnet 33 in the z-axis direction. In the vicinity thereof, the range in which the distribution in the z-axis direction of magnetic lines of force (magnetic flux density in the y-axis direction) from the N pole of the first magnet 31 to the S pole of the third magnet 33 becomes small.

  That is, when the ratio p (= wb / wa) is less than 0.5, the width wa is relatively increased, the magnetic flux density is decreased, and the output power is decreased. By setting the ratio p (= wb / wa) to 0.5 or more, the y-axis direction component of the magnetic flux density of the magnetic flux passing through one of the road walls (11, 12) of the power generation side circulation channels 10a, 10b ( The uniformity of the distribution in the z-axis direction) can be increased, and the output power can be increased.

  In the present embodiment, the ratio q of the magnet thickness dimension t (dimension in the y-axis direction) to the separation dimension d (gap dimension in the y-direction) between the pair of magnets (31, 32, 33, 34). = T / d) is 3 or more. When the ratio q (= t / d) is less than 3, the separation dimension d is relatively increased, the magnetic flux density is decreased, and the output power is decreased. By setting the ratio q (= t / d) to 3 or more, the magnetic flux density can be increased and the output power can be increased.

  In the present embodiment, the pair of magnets (31, 32, 33, 34) are neodymium magnets having a residual magnetic flux density of 1.33 T or more. By using a neodymium magnet having a residual magnetic flux density of 1.33 T or more, the magnetic flux density can be increased.

  Moreover, in this Embodiment, the magnetic flux density of the magnetic field which a magnetic field application part applies is 1.0 T or more. Since the output power is proportional to the square of the magnetic flux density, the required power can be obtained by setting the magnetic flux density to 1.0 T or more.

  Next, numerical examples of the first embodiment will be described. In the example of FIG. 4, for example, the length L of the first magnet 31, the second magnet 32, the third magnet 33, and the fourth magnet 34 (that is, the length of the electrode plates 15 and 16) L is 100 mm, and the first magnet The total width (wa + 2 × wb) of the width wb of 31 and the third magnets 33 and 33 arranged on both sides (wa + 2 × wb) is 52.5 mm, the width wa of the second magnet 32 and the fourth magnets 34 arranged on both sides, The total width (wa + 2 × wb) of 34 is 52.5 mm, the thickness t of the first magnet 31, the second magnet 32, the third magnet 33 and the fourth magnet 34 is 30 mm, the gap d is 5 mm, and the power generation side The width of each road wall of the circulation channel 10a is 5 mm, and the z-axis coordinate (height from the inner surface of the lower yoke 35) of the center position of the power generation side circulation channel 10a is 26.25 mm. The analysis result of the magnetic field applied by the power generation unit 30 based on such numerical examples will be described below. The first magnet 31, the second magnet 32, the third magnet 33, and the fourth magnet 34 are neodymium magnets having a high residual magnetic flux density Br of 1.38T. The numerical examples are not limited to the above examples.

  FIG. 9 is an explanatory diagram illustrating an example of a magnetic field analysis result when the ratio p by the power generation unit 30 of the first example of the first embodiment is 0.5. The magnetic flux density shown in FIG. 9 represents the magnetic flux density component By in the y direction. Since the ratio p is 0.5, the width wa is 26.25 mm and the width wb is 13.125 mm. The upper diagram in FIG. 9 shows the distribution of the magnetic flux density By in the x direction at z = 26.25 mm. In the range of x = 20 to 80 mm, the magnetic flux density By is about 1.3T, and the magnetic flux density By in the x direction is uniform.

  The middle diagram of FIG. 9 shows the distribution of the magnetic flux density By in the y direction at z = 26.25 mm. The magnetic flux density By in the y direction becomes a constant value, and the magnetic flux density By in the y direction in the flow path of the power generation side circulation flow path 10a can be made uniform.

  The lower diagram of FIG. 9 shows the distribution of the magnetic flux density By in the z direction at the center of the gap d, that is, at the center of the power generation side circulation passage 10a. In the range of z = 15 to 35 mm, the maximum value of the magnetic flux density By is substantially uniform.

  FIG. 10 is an explanatory diagram illustrating an example of a magnetic field analysis result when the ratio p by the power generation unit 30 of the first example of the first embodiment is 1.0. The magnetic flux density shown in FIG. 10 represents the magnetic flux density component By in the y direction. Since the ratio p is 1.0, the width wa and the width wb are 17.7 mm. The upper diagram in FIG. 10 shows the distribution of the magnetic flux density By in the x direction at z = 26.25 mm. In the range of x = 20 to 80 mm, the magnetic flux density By is about 1.5 T, and the magnetic flux density By in the x direction is uniform.

  The middle diagram of FIG. 10 shows the distribution of the magnetic flux density By in the y direction at z = 26.25 mm. The magnetic flux density By in the y direction becomes a constant value, and the magnetic flux density By in the y direction in the flow path of the power generation side circulation flow path 10a can be made uniform.

  The lower diagram of FIG. 10 shows the distribution of the magnetic flux density By in the z direction at the center of the gap d, that is, at the center of the power generation side circulation channel 10a. In a range of z = 20 to 33 mm, the maximum value of the magnetic flux density By is substantially uniform.

  FIG. 11 is an explanatory diagram showing an example of a magnetic field analysis result when the ratio p by the power generation unit 30 of the first example of the first embodiment is 1.5. The magnetic flux density shown in FIG. 11 represents a magnetic flux density component By in the y direction. Since the ratio p is 1.5, the width wa is 13.125 mm and the width wb is about 19.69 mm. The upper part of FIG. 11 shows the distribution of the magnetic flux density By in the x direction at z = 26.25 mm. In the range of x = 20 to 80 mm, the magnetic flux density By is about 1.65 T, and the magnetic flux density By in the x direction is uniform.

  The middle diagram of FIG. 11 shows the distribution of the magnetic flux density By in the y direction at z = 26.25 mm. The magnetic flux density By in the y direction becomes a constant value, and the magnetic flux density By in the y direction in the flow path of the power generation side circulation flow path 10a can be made uniform.

  The lower diagram of FIG. 11 shows the distribution of the magnetic flux density By in the z direction at the center of the gap d, that is, at the center of the power generation side circulation channel 10a. In the range of z = 23 to 30 mm, the maximum value of the magnetic flux density By is substantially uniform.

  FIG. 12 is an explanatory diagram illustrating an example of a magnetic field analysis result when the ratio p by the power generation unit 30 of the first example of the first embodiment is 2.0. The magnetic flux density shown in FIG. 12 represents a magnetic flux density component By in the y direction. Since the ratio p is 2.0, the width wa is 10.5 mm and the width wb is 21 mm. The upper part of FIG. 12 shows the distribution of the magnetic flux density By in the x direction at z = 26.25 mm. In the range of x = 20 to 80 mm, the magnetic flux density By is about 1.75 T, and the magnetic flux density By in the x direction is uniform.

  The middle diagram of FIG. 12 shows the distribution of the magnetic flux density By in the y direction at z = 26.25 mm. The magnetic flux density By in the y direction becomes a constant value, and the magnetic flux density By in the y direction in the flow path of the power generation side circulation flow path 10a can be made uniform.

  The lower diagram of FIG. 12 shows the distribution of the magnetic flux density By in the z direction at the center of the gap d, that is, at the center of the power generation side circulation channel 10a. In the range of z = 24 to 29 mm, the maximum value of the magnetic flux density By is substantially uniform.

  FIG. 13 is an explanatory diagram illustrating an example of a magnetic field analysis result when the ratio p by the power generation unit 30 of the first example of the first embodiment is 3.0. The magnetic flux density shown in FIG. 13 represents the magnetic flux density component By in the y direction. Since the ratio p is 3.0, the width wa is 7.5 mm and the width wb is 22.5 mm. The upper part of FIG. 13 shows the distribution of the magnetic flux density By in the x direction at z = 26.25 mm. In the range of x = 20 to 80 mm, the magnetic flux density By is about 1.8 T, and the magnetic flux density By in the x direction is uniform.

  The middle diagram of FIG. 13 shows the distribution of the magnetic flux density By in the y direction at z = 26.25 mm. The magnetic flux density By in the y direction becomes a constant value, and the magnetic flux density By in the y direction in the flow path of the power generation side circulation flow path 10a can be made uniform.

  The lower diagram of FIG. 13 shows the distribution of the magnetic flux density By in the z direction at the center of the gap d, that is, at the center of the power generation side circulation channel 10a. Near z = 25, the magnetic flux density By is maximized.

  As can be seen from the examples in FIGS. 9 to 13, when the ratio p (= wb / wa) is 0.5 or more, the magnetic flux density By is almost dependent on the x-axis direction, the y-axis direction, and the z-axis direction. (That is, the distribution of the y-direction component By of the magnetic flux density is uniform in the x-axis direction, the y-axis direction, and the z-axis direction), and the magnetic flux density By can be ensured to be 1.0 T or more.

  In addition, when the ratio p (= wb / wa) is greater than 0.5, the magnetic flux density By can be further increased.

  On the other hand, when the ratio p (= wb / wa) is about 2.0, the range in which the distribution of the magnetic flux density By in the z-axis direction is uniform becomes z = 24 to 29 mm. Therefore, by setting the ratio p (= wb / wa) to 2.0 or less, the magnetic flux density By in the z direction in the flow path can be increased even if the power generation side circulation flow path 10a having a width dimension of about 5 mm or more is disposed. It can be made uniform.

  That is, the ratio p may be 0.5 or more, but most preferably, the ratio p is about 2.0.

  Next, numerical examples of the second embodiment will be described. In the example of FIG. 7, for example, the length L of the first magnet 31, the second magnet 32, the third magnet 33, and the fourth magnet 34 (that is, the length of the electrode plates 15 and 16) L is 100 mm, and the first magnet 31 and the width w of the second magnet 32 and the width wb of the second magnet 32 and the fourth magnet 34 are 10 mm, respectively, and the thickness t of the first magnet 31, the second magnet 32, the third magnet 33 and the fourth magnet 34 is set to 10 mm. 30 mm, the gap d is 5 mm, the width of each wall of the power generation side circulation channels 10 a and 10 b is 5 mm, and the z-axis coordinates of the center position of the lower power generation side circulation channel 10 b (the inner surface of the lower yoke 35) Height) W1 is 15 mm, and the z-axis coordinate (height from the inner surface of the lower yoke 35) W2 of the center position of the upper power generation side circulation passage 10a is 35 mm. The analysis result of the magnetic field applied by the power generation unit 30 based on such numerical examples will be described below. The first magnet 31, the second magnet 32, the third magnet 33, and the fourth magnet 34 are neodymium magnets having a high residual magnetic flux density Br of 1.38T. The numerical examples are not limited to the above examples.

  FIG. 14 is an explanatory diagram illustrating an example of a magnetic field analysis result when the ratio p by the power generation unit 30 of the second example of the first embodiment is 1.0. The magnetic flux density shown in FIG. 14 represents a magnetic flux density component By in the y direction. 14 shows the distribution of the magnetic flux density By in the x direction at z = 15 mm. 14 shows the distribution of the magnetic flux density By in the x direction at z = 35 mm. In the range of x = 20 to 80 mm, the magnetic flux density By is about 1.35T or −1.35T, and the magnetic flux density By in the x direction is uniform.

  The lower left diagram in FIG. 14 shows the distribution of the magnetic flux density By in the y direction at z = 15 mm and z = 35 mm. The magnetic flux density By in the y direction becomes a constant value, and the magnetic flux density By in the y direction in the flow path of the power generation side circulation flow path 10a can be made uniform.

  14 shows the distribution of the magnetic flux density By in the z direction at the center of the gap d, that is, the center of the power generation side circulation channels 10a and 10b. In the range of z = 12 to 17 mm and the range of z = 34 to 39 mm, the maximum value of the magnetic flux density By is substantially uniform.

  FIG. 15 is an explanatory diagram illustrating an example of a magnetic field analysis result when the thickness of the magnet is changed by the power generation unit 30 of the first embodiment. The magnetic flux density shown in FIG. 15 represents the magnetic flux density component By in the y direction. The upper diagram in FIG. 15 shows the magnetic flux density component in the y direction when the thickness t of the first magnet 31, the second magnet 32, the third magnet 33, and the fourth magnet 34 is changed to 15 mm, 30 mm, 45 mm, and 90 mm. The distribution of By in the x direction is shown, and the lower diagram in FIG. 15 plots the maximum value of the magnetic flux density By when the thickness t is changed to 15 mm, 30 mm, 45 mm, and 90 mm. Since the gap d is 5 mm, the thickness t is 15 mm, 30 mm, 45 mm, and 90 mm, and the ratio q (= t / d) corresponds to 3, 6, 9, and 18, respectively. The magnetic flux density By increases as the magnet thickness t, that is, the ratio q increases. It can be seen that in order to make the magnetic flux density By approximately 1.0 T or more, the ratio q should be 3 or more.

  Note that when the width of the road walls of the power generation-side circulation channels 10a and 10b is determined in advance, the distance d between the pair of magnets is also determined, but the magnetic flux density By is increased as the magnet thickness t is increased. be able to. However, if the thickness t is increased, the size of the magnetic field application unit is increased and the entire apparatus is increased. However, the ratio q may be increased within the allowable range of the size of the apparatus. For example, if the ratio q is changed from 3 to 6, the magnetic flux density By can be increased by about 50%.

  A configuration using only the first magnet 31 and the third magnet 33 of the same size and the same material as the first embodiment or the second embodiment described above, that is, one of the magnets with the power generation side circulation passage 10a in between. When the N pole and the S pole of the other magnet are arranged to face each other, the magnetic flux density of the magnetic flux that can be applied to the power generation side circulation channels 10a and 10b is 0.8 T or less. Compared to the case where the N pole of one magnet and the S pole of the other magnet are arranged opposite to each other with the power generation side circulation passage 10a in between by adopting the configuration of the first embodiment or the second embodiment described above. Thus, the magnetic flux density of the magnetic flux that can be applied to the power generation side circulation channels 10a and 10b can be increased by 25% or more.

(Second Embodiment)
FIG. 16 is a schematic diagram showing an example of the configuration of the ferrofluid power generation device 100 of the second embodiment. As shown in FIG. 16, the second embodiment includes a plurality of circulation channels 10 in which the drive unit 20 is interposed. In other words, the drive unit 20 is provided with a plurality of circulation channels 10. In the example of FIG. 16, the drive unit 20 is provided with four circulation channels 10.

  The merging unit 50 merges the circulation channels 10 so that the number of the power generation-side circulation channels 10 a and 10 b is smaller than the number of the circulation channels 10. For example, as shown in FIG. 16, when the drive unit 20 is provided with four circulation channels 10 and the power generation unit 30 is provided with two power generation side circulation channels 10a and 10b, the merging unit 50 is The four flow paths are merged with the two flow paths on the upstream side of the power generation side circulation flow path. It should be noted that a branching portion 51 in which two flow paths are branched into four flow paths is arranged on the downstream side of the power generation side circulation flow path.

  That is, the total cross-sectional area of the power generation-side circulation flow paths 10a and 10b is smaller than the total cross-sectional area of the circulation flow path 10 in which the drive unit 20 is interposed.

  If the flow velocity of the magnetic fluid driven by the drive unit 20 is u, and the flow channel cross-sectional areas of the circulation flow channel 10 and the power generation side circulation flow channels 10a and 10b are the same, the flow rate (volume flow rate) Q is constant. The flow velocity of the magnetic fluid in the power generation side circulation channels 10a and 10b is about double. As a result, the voltage generated between the electrode plates 15 and 16 can be doubled, and since the power is proportional to the square of the voltage, the power output from the electrode plates 15 and 16 can be quadrupled. The output power can be increased.

  Further, the number of the circulation channels 10 in which the drive unit 20 is interposed and the number of the power generation side circulation channels 10 a and 10 b are set to be the same, and the power generation side circulation channels are more than the cross-sectional area of each circulation channel 10. The cross-sectional areas of 10a and 10b can be reduced. Furthermore, the number of power generation side circulation channels 10 a and 10 b is less than the number of circulation channels 10 in which the drive unit 20 is interposed, and each power generation side circulation channel 10 a is smaller than the cross-sectional area of each circulation channel 10. The cross-sectional area of 10b can be reduced.

  FIG. 17 is an explanatory diagram showing a numerical example of the power generated by the power generation unit 30. The upper part of FIG. 17 is a case corresponding to the first example of the first embodiment, where the number of the circulation channel 10 and the power generation side circulation channel 10a is one, and the channel length is 0.8 m. An example is shown. When the magnetic fluid is a water-based magnetic fluid, the conductivity is 5.25 [S / m], and the power generation amount is 0.075 [mW]. When the magnetic fluid is a phosphoric acid electrolyte magnetic fluid, the electrical conductivity is 50 [S / m], and the power generation amount is 0.71 [mW].

  The lower part of FIG. 17 is a case corresponding to the second embodiment, in which there are four circulation channels 10 on the drive unit 20 side and two power generation side circulation channels 10a and 10b. An example in which the channel length is 0.8 m is shown. When the magnetic fluid is a water-based magnetic fluid, the conductivity is 5.25 [S / m], and the power generation amount is 0.60 [mW]. When the magnetic fluid is a phosphoric acid electrolyte magnetic fluid, the electrical conductivity is 50 [S / m], and the power generation amount is 5.68 [mW].

  As described above, according to the first and second embodiments, the magnetic fluid can be circulated and driven only by the permanent magnet and the heat source, and power can be generated by the circulated and driven magnetic fluid. It is possible to realize a power generation device or a power supply device that can be miniaturized in a normal temperature environment and a safe environment using the waste heat of the region.

  In the above-described embodiment, the circulation channel has a configuration arranged in a substantially rectangular shape, but is not limited to such a configuration, and for example, the circulation channel may be arranged in a circular shape, or power generation It can also be arranged in other shapes depending on the space in the device in which the device is incorporated.

  It should be noted that at least a part of the above-described embodiments can be arbitrarily combined.

DESCRIPTION OF SYMBOLS 10 Circulation flow path 10a, 10b Power generation side circulation flow path 11, 12, 13, 14 Road wall 15, 16 Electrode plate 20 Drive part 21 Magnetic field production | generation part 211 Permanent magnet 212 Yoke 22 Heating part 30 Power generation part 31 1st magnet (magnetic field) Application section)
32 Second magnet (magnetic field application unit)
33 Third magnet (magnetic field application unit)
34 Fourth magnet (magnetic field application unit)
35 Yoke 36 Gap 50 Junction 51 Divergence

Claims (6)

A circulation flow path for circulating the magnetic fluid, and a drive unit that is interposed in the circulation flow path and applies a magnetic field to the magnetic fluid sealed in the circulation flow path and heats the magnetic fluid to drive circulation. A ferrofluid power generator,
The magnetic fluid has conductivity,
A power generation unit interposed in the circulation channel;
The power generation unit
A power generation-side circulation channel that communicates with the circulation channel and is surrounded by two sets of road walls facing each other over a predetermined length and having a rectangular cross-sectional shape;
A magnetic field application unit that applies a magnetic field in a direction substantially perpendicular to one of the facing road walls;
An electrode plate provided on each of the other opposite road walls,
Ri Citea to output power via the electrode plates,
The magnetic field application unit is
A pair of magnets, each paired on each one of the road walls, surrounded by a yoke;
One of the pair of magnets is
A first magnet that is magnetized in a direction substantially perpendicular to the road wall and toward the road wall, and is wider than the road wall;
A pair of second magnets that are opposed to each other with the first magnet interposed therebetween and are substantially parallel to the surface of the road wall and magnetized in the direction of the first magnet;
Have
The other of the pair of magnets is
A third magnet that is magnetized in a direction substantially perpendicular to the road wall and opposite to the direction toward the road wall, and wider than the road wall;
A pair of fourth magnets that are opposed to each other with the third magnet interposed therebetween and are magnetized in a direction that is substantially parallel to the surface of the road wall and opposite to the direction of the third magnet;
Have
The ratio of the width of the second magnet to the width of the first magnet, and the ratio of the width of the fourth magnet to the width of the third magnet, the magnetic fluid power generator according to claim der Rukoto 0.5 or more.   The magnetic fluid power generator according to claim 1, wherein the magnetic fluid has a conductivity of 1 S / m or more.   3. The magnetic fluid power generation device according to claim 1, wherein a total cross-sectional area of the power generation-side circulation flow path is smaller than a total cross-sectional area of the circulation flow path in which the driving unit is interposed. Ratio of thickness of the magnet relative separation distance of the magnet between the pair, the magnetic fluid power generator according to item 1 or to claims 1 to 3, characterized in that three or more. The ferrofluid power generation device according to any one of claims 1 to 4, wherein the pair of magnets are neodymium magnets having a residual magnetic flux density of 1.33 T or more. The magnetic fluid power generator according to any one of claims 1 to 5, wherein a magnetic flux density of a magnetic field applied by the magnetic field application unit is 1.0 T or more.

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