JP5435357B2 - Power generation system - Google Patents

Description

  The present invention uses induction heating to convert rotational energy (mechanical energy) into heat energy and heat the heat medium, and a power generation unit that converts heat of the heat medium into electric energy. The present invention relates to a power generation system provided.

  As a device for heating water, a heating device using induction heating (eddy current) has been proposed (for example, see Patent Document 1). The eddy current heating device described in Patent Document 1 is a conductive rotor having a rotatable rotor having a permanent magnet arranged on the outer periphery and a fixed passage provided on the outer periphery of the rotor, and a flow passage through which water flows. A heating part for the material. As the rotor rotates, the magnetic lines of force generated by the permanent magnets on the outer periphery of the rotor move through the heating unit, so that an eddy current is generated in the heating unit and the heating unit itself generates heat. As a result, the heat generated in the heating unit is transmitted to the water flowing through the internal flow passage, and the water is heated.

  The above-mentioned technology is mainly intended to supply hot water using energy such as wind power, but in recent years, power generation systems using renewable energy such as wind power, hydraulic power, and wave power are also attracting attention. .

  For example, Non-Patent Documents 1 to 3 describe technologies relating to wind power generation. In wind power generation, a windmill is rotated by wind and a generator is driven to generate electric power. Wind energy is converted into rotational energy and extracted as electric energy. A wind power generation system generally has a structure in which a nacelle is installed at the top of a tower, and a horizontal axis wind turbine (a wind turbine whose rotation axis is substantially parallel to the wind direction) is attached to the nacelle. The nacelle stores a speed increaser that speeds up and outputs the rotational speed of the rotating shaft of the windmill, and a generator that is driven by the output of the speed increaser. The speed increaser increases the number of rotations of the wind turbine to the number of rotations of the generator (for example, 1: 100), and a gear box is incorporated.

  Recently, there is a tendency to increase the size of a windmill (wind power generation system) in order to reduce the power generation cost, and a wind power generation system with a wind turbine diameter of 120 m or more and an output per unit of 5 MW has been put into practical use. Such large-scale wind power generation systems are huge and heavy, and are often constructed offshore for construction reasons.

  In wind power generation, the power generation output (power generation amount) fluctuates with the fluctuation of wind power. Therefore, a power storage system is added to the wind power generation system, unstable power is stored in the storage battery, and the output is smoothed. It has been broken.

JP 2005-174801 A

“Wind Power Generation (01-05-01-05)”, [online], Atomic Encyclopedia ATOMICA, [Search February 8, 2010], Internet <URL: http://www.rist.or.jp/ atomica /> “2000kW large wind power generation system SUBARU80 / 2.0 PROTOTYPE”, [online], Fuji Heavy Industries Ltd., [searched on February 8, 2010], Internet <URL: http://www.subaru-windturbine.jp/home/ index.html> “Wind Wind Course”, [online], Mitsubishi Heavy Industries, Ltd., [Search February 8, 2010], Internet <URL: http://www.mhi.co.jp/products/expand/wind_kouza.html>

  However, in the conventional induction heating apparatus as described in Patent Document 1 described above, since a permanent magnet is used as a means for generating a magnetic field (lines of magnetic force), the following problems may occur.

  The induction heating energy is proportional to the square of the magnetic field strength (H). However, since a magnetic field that can generally be generated by a permanent magnet is weak, sufficient induction heating energy cannot be obtained, and a heat medium (for example, up to a desired temperature) , Liquid such as water) may not be heated.

  In addition, it is conceivable to use a neodymium magnet to obtain a strong magnetic field (see, in particular, paragraph 0037 of Patent Document 1), but the neodymium magnet is vulnerable to heat, and as the temperature rises, the magnetic properties deteriorate (this) The same applies to general ferrite magnets). Therefore, in the conventional induction heating apparatus in which the permanent magnet is arranged near the heating unit, the temperature of the permanent magnet is likely to rise, the magnetic characteristics are lowered, and as a result, the heating medium is heated to a desired temperature. There is a possibility that it cannot be done. Furthermore, since permanent magnets deteriorate in magnetic characteristics over time, there is a possibility that they cannot be used for a long time. By the way, in order to prevent the deterioration (deterioration) of the magnetic properties due to heat, it is conceivable to provide a heat insulating material around the permanent magnet. However, since the heat insulating material is usually a non-magnetic material, it is between the permanent magnet and the heating part. There is a possibility that the magnetic gap becomes larger than a predetermined value, resulting in a decrease in the magnetic field.

  On the other hand, in a generally well-known wind power generation system, a power storage system is installed for smoothing the output. However, since the power storage system requires components such as a converter to store power in the storage battery, This increases complexity and power loss. Further, in the case of a large-scale wind power generation system, a large-capacity storage battery corresponding to the amount of power generation is required, which increases the cost of the entire system.

  Moreover, many of the causes of failure of the wind power generation system are due to problems with the gearbox, more specifically, the gear box. When a gearbox breaks down, it is usually dealt with by exchanging the gearbox. However, if a nacelle is installed at the top of the tower, it takes a lot of time and labor to install and remove the gearbox. Therefore, recently, there is a gearless variable-speed wind generator that does not require a gear box.

  However, the gearless case can be dealt with by specifically increasing the number of poles of the generator (multipolar generator), but the generator becomes larger and heavier than when using a speed increaser. In particular, in a large-scale wind power generation system of 5 MW class, the weight of the generator is considered to exceed 300 tons (300000 kg), and it is difficult to arrange in the nacelle.

  The present invention has been made in view of the above circumstances, and one of its purposes is to have a performance suitable for heating a heat medium to a temperature necessary for power generation. It is to provide a power generation system that generates electricity by converting to energy.

  The power generation system of the present invention includes an induction heating device that heats a heat medium, and a power generation unit that converts heat of the heat medium into electric energy. This induction heating apparatus includes a rotating body, a coil, a heating unit, and piping. The rotating body is formed by combining both a first rotating body that is formed at least in part from a magnetic material and has a rotating shaft and a second rotating body that is connected to the first rotating body. The coil is disposed between the first rotating body and the second rotating body such that one magnetic pole and the other magnetic pole face the first rotating body and the second rotating body, and a magnetic field is provided in the axial direction of the rotating body. Is generated. At least a part of the heating unit is formed of a conductive material, and is disposed outside the rotating body and spaced from the rotating body. Piping is provided in a heating part and a heat carrier distribute | circulates. In addition, at least one convex portion protruding in the radial direction of the rotating body is formed on both the first rotating body and the second rotating body, and the both convex portions are displaced from each other in the circumferential direction. And extending toward the other side and spaced apart from each other.

  The power generation system of the present invention is a novel power generation system that does not have a conventional power generation system that uses heat of a heat medium heated by using an induction heating device for power generation. For example, if a windmill is connected to the rotating shaft of the induction heating device and wind power is used as the power of the rotating body, the wind energy can be converted from rotational energy to thermal energy and extracted as electrical energy. And according to the electric power generation system of this invention, it was set as the structure which converts heat into an electrical energy, By storing energy as heat using a thermal accumulator, an efficient and stable electric power generation system is realizable. In addition, a heat storage system that can store heat in the heat accumulator and simultaneously extract heat necessary for power generation from the heat accumulator is simpler than the power storage system, and the heat accumulator is less expensive than the storage battery. Further, it is not necessary to use a speed increaser as in the conventional power generation system, and it is possible to avoid a gearbox trouble.

  In addition, since the induction heating device in the power generation system of the present invention uses a coil as the magnetic field generation means, it can generate a stronger magnetic field as compared with a conventional device using a permanent magnet. Specifically, it is possible to generate a strong magnetic field by increasing the current applied to the coil, and it is also possible to adjust the strength of the magnetic field by controlling the applied current. In addition, in the case of a coil, compared to a permanent magnet, the magnetic characteristics are less likely to deteriorate due to a temperature rise, and the magnetic characteristics are less likely to deteriorate over time. Therefore, by using a coil as the magnetic field generating means, it is easy to maintain a sufficient magnetic field strength by increasing the energization current, and the temperature of the heat medium required for power generation (for example, 100 ° C. to 600 ° C., preferably 200 ° C. to 350 ° C. ) Sufficient performance (heat energy) can be obtained. Note that a direct current is passed through the coil to generate a direct magnetic field.

  In addition, the induction heating device is provided with a pipe in a fixed heating section that does not rotate, so that the pipe rotates to connect the supply and discharge pipe that communicates with the pipe and supplies and discharges the heat medium from the outside. Therefore, it is not necessary to use a rotary joint that allows for a strong connection with a simple configuration. Specifically, when the heat medium is heated, the pressure in the pipe increases. For example, when the heat medium is water (steam), the pressure reaches about 25 MPa (250 atm) at 600 ° C. When the heating part (pipe) rotates, a special rotary joint that can withstand the pressure is required. When it does not rotate, there is no need for a rotary joint. For example, a simple connection such as welding the supply / discharge pipe and the pipe By adopting this method, a sufficiently robust structure can be realized.

  The heating mechanism of the heat medium in this induction heating apparatus will be described. When the coil is energized, the first rotating body facing one magnetic pole of the coil is magnetized to the same polarity as the one magnetic pole, and the second rotating body facing the other magnetic pole of the coil is Magnetized to the same polarity. As a result, the convex portions of both the first rotating body and the second rotating body are magnetized to have different polarities, and in the cross section orthogonal to the axial direction of the rotating body, both convex portions are spaced apart in the circumferential direction of the rotating body. Since they are alternately arranged, the polarities of adjacent convex portions of the rotating body are different from each other. The magnetic flux that has flowed out of the convex portions of both the first rotating body and the second rotating body passes through the heating unit disposed outside the rotating body (convex portion). When the rotating body rotates, the magnetic flux passing through the heating unit changes, and an induction current is generated in the heating unit, whereby the heating unit is induction-heated and the heat medium is heated.

  It is preferable to provide a plurality of convex portions on each of the first rotating body and the second rotating body (for example, two or more, and a total of four or more in total). It is preferable to provide at equal intervals in the direction.

  In the present invention, examples of the magnetic material used for the rotating body of the induction heating apparatus include iron, nickel, cobalt, silicon steel, permalloy, and ferrite. Moreover, as a conductive material used for a heating part, metals, such as aluminum, copper, and iron, are mentioned, for example. In particular, by using aluminum for the heating unit, it is possible to reduce the weight of the heating unit, thereby reducing the weight of the induction heating device. Examples of the heat medium include water, oil, liquid metals (Na, Pb, etc.), liquids such as molten salts, and gases.

  As one form of the power generation system of the present invention, it further includes a stator portion that is disposed on the outer periphery of the heating portion and is made of a magnetic material. The stator portion has a cylindrical shape, and protrudes in a centripetal manner from the cylindrical portion. The heating part is attached to the inner peripheral surface of the stator part, and has a hole through which the protruding part is inserted.

  According to this structure, the circumference | surroundings of the projection part in the stator part of an induction heating apparatus can be enclosed with the electrically-conductive material which forms a heating part. When the distance between the convex portion of the rotating body and the protrusion of the stator portion becomes narrow → wide or wide → narrow due to the rotation of the rotating body, and the magnetic flux flowing through the protrusion changes, heating around the protrusion In the part, an induced electromotive force (counterelectromotive force) is generated and heated by a current flowing. Therefore, according to this configuration, the heat medium can be heated using the induced electromotive force in the heating portion around the protrusion, and the presence of the protrusion can be compared with the case where there is no protrusion. The amount of magnetic flux flowing from the protrusion to the protrusion increases when the distance between the rotating body (protrusion) and the stator (protrusion) is narrow. As a result, it is possible to increase the change in magnetic flux flowing through the protrusions of the stator portion, increase the induced electromotive force, and improve the heating efficiency.

  It is preferable to provide a plurality of projections (for example, four or more), and when providing a plurality of projections, it is preferable to provide them at equal intervals in the circumferential direction of the stator unit.

  Examples of the magnetic material used for the stator portion include iron, nickel, cobalt, silicon steel, permalloy, and ferrite.

  One form of the power generation system of the present invention is that the coil is a superconducting coil.

  Examples of the coil of the induction heating device include a normal conducting coil such as a copper wire and a superconducting coil using a superconducting wire. When a direct current is passed through the coil to generate a direct current magnetic field, if it is a superconducting coil, the electric resistance is zero, and even if a large current is passed through, no substantial heat (loss) is generated in the coil. Therefore, compared with a normal conducting coil, heat generation (loss) of the coil caused by flowing a large current can be suppressed, and an extremely strong magnetic field can be maintained without power loss even in a large space. In addition, the superconducting wire has a high current density, so that the coil can be reduced in size and weight, and the induction heating device can be reduced in size and weight. For example, when trying to obtain thermal energy suitable for large-scale power generation, the use of a superconducting coil can reduce power consumption and reduce the size and weight of the device compared to a normal conducting coil. It becomes easy to arrange in the nacelle.

  As one form of the electric power generation system of this invention, a rotating shaft is connected to a windmill and using wind power for the motive power which rotates a rotary body is mentioned.

In the power generation system of the present invention, it is preferable to use renewable energy such as wind power, hydraulic power, and wave power for the power of the rotating body (rotating shaft) of the induction heating device. If renewable energy is used, an increase in CO ₂ can be suppressed, and it is particularly preferable to use wind power.

  Since the power generation system of the present invention uses a coil as the magnetic field generating means of the induction heating device, it can generate a very strong magnetic field and can easily heat the heat medium to a temperature required for power generation. And the heat | fever of the heat medium heated using the induction heating apparatus can be converted into electric energy by the power generation part, and can be generated.

It is the schematic of the induction heating apparatus which concerns on Embodiment 1, (A) is a disassembled perspective view, (B) is a perspective view which shows an assembly state. 2 is a schematic exploded perspective view of a rotating body in the induction heating apparatus according to Embodiment 1. FIG. It is the schematic front sectional drawing which cut | disconnected the induction heating apparatus which concerns on Embodiment 1 in the orthogonal direction with the axial direction of a rotary body. It is a figure which shows typically the time change of the magnetic field in the point a of FIG. It is the schematic of the induction heating apparatus which concerns on Embodiment 2, (A) is a disassembled perspective view, (B) is front sectional drawing cut | disconnected in the direction orthogonal to the axial direction of a rotary body. It is the partial expansion schematic of the induction heating apparatus which concerns on Embodiment 2, (A) shows one state in which the rotary body is rotating, (B) shows another state in which the rotary body is rotating. FIG. 10 is a schematic perspective view showing a modification of the stator portion in the induction heating device according to the second embodiment. It is the schematic which shows the example of arrangement | positioning of the piping in an induction heating apparatus, (A) is an expansion | deployment top view in the case of comprising with one piping, (B) is an expansion | deployment top view in the case of comprising with two piping. (C) is a developed plan view in the case of comprising four pipes. (D) is an expanded plan view showing an attachment example of connection conductors for electrically connecting pipe portions in the arrangement example of FIG. It is a schematic side view which shows another example of arrangement | positioning of piping in an induction heating apparatus. It is the schematic which shows an example of the whole structure of the electric power generation system which concerns on this invention. It is a figure which shows typically the simulation model used for the trial calculation example 1. FIG. It is a figure which shows the trial calculation result of the total cost in a simulation model.

  Embodiments of the present invention will be described with reference to the drawings. In the drawings, the same reference numerals indicate the same or corresponding parts.

  The power generation system of the present invention includes an induction heating device that heats a heat medium, and a power generation unit that converts heat of the heat medium into electric energy. Here, the induction heating apparatus will be described first, and then the entire power generation system will be described.

<Induction heating device>
(Embodiment 1)
The induction heating device 101 according to the first embodiment shown in FIGS. 1 to 3 includes a rotating body 11, a coil 12, a heating unit 13, a pipe 14, and a stator unit 15. Hereinafter, the configuration of the induction heating apparatus 101 will be described in detail.

  The rotating body 11 is formed by combining both a first rotating body 11a having a rotating shaft 21 that is rotatably supported and a second rotating body 11b that is connected to the first rotating body 11a. Both the first rotating body 11a and the second rotating body 11b are formed with a plurality of convex portions 111a and 111b protruding in the radial direction of the rotating body 11, and the respective convex portions 111a and 111b are mutually connected. In a state shifted in the circumferential direction, they extend toward the other side and are separated from each other. That is, the first rotator 11a and the second rotator 11b are arranged to face each other so that the convex portions 111a and 111b are engaged with each other. Further, both the convex portions 111 a and 111 b are provided at equal intervals in the circumferential direction of the rotating body 11. In this example, eight convex portions are formed on each of the first rotating body 11a and the second rotating body 11b, and a total of 16 convex portions are provided on the rotating body 11 in total. The rotating body 11 (first rotating body 11a and second rotating body 11b) is made of a magnetic material such as iron. Here, it is assumed that the rotating body 11 rotates counterclockwise as viewed from the rotating shaft 21 side (the arrow in FIG. 3 indicates the rotating direction of the rotating body 11. FIGS. 5B and 6 also). the same).

  The coil 12 is disposed between the first rotating body 11a and the second rotating body 11b so that one magnetic pole and the other magnetic pole face the first rotating body 11a and the second rotating body 11b. A magnetic field is generated in the direction of 11 axes. That is, when the coil 12 disposed inside the rotating body 11 is excited by energization, the first rotating body 11a facing one magnetic pole is magnetized to the same polarity as one magnetic pole and facing the other magnetic pole. The second rotating body 11b is magnetized to the same polarity as the other magnetic pole. At this time, the convex portions 111a and 111b of the first rotating body 11a and the second rotating body 11b are also magnetized. A DC power source (not shown) is connected to the coil 12. In this example, the coil 12 is a superconducting coil, and the direction of the direct current flowing through the coil 12 is controlled to determine the direction of the magnetic field (magnetic flux) to be generated. Has become the S pole. Further, the superconducting coil 12 is covered with a cooling jacket (not shown) and is kept in a superconducting state by cooling.

  In this example, the first rotating body 11a and the second rotating body 11b are connected via a columnar connecting member 112 disposed inside the center, and the connecting member 112 is inserted inside the coil 12. In addition, the coil 12 is supported (see FIG. 2). The material for forming the connecting member 112 may be any material that has mechanical strength and can support the coil 12, regardless of whether it is a magnetic material or a non-magnetic material, and is preferably a material that is excellent in structural strength and long-term weather resistance. . Examples thereof include composite materials such as iron, steel, stainless steel, aluminum alloy, magnesium alloy, GFRP (glass fiber reinforced plastic) and CFRP (carbon fiber reinforced plastic) used for structural materials.

  Here, the connecting member 112 is made of a nonmagnetic material. For example, when the connecting member 112 is formed of a magnetic material, the magnetic field generated by the superconducting coil 12 may be limited due to saturation of the magnetic flux of the connecting member 112. Therefore, the connecting member 112 may be formed of a nonmagnetic material. It may be preferable. In addition, examples of the shape of the connecting member 112 include a columnar shape, a cylindrical columnar shape, a polygonal columnar shape, and a polygonal cylindrical columnar shape, and a preferable shape may be appropriately selected as necessary.

  The heating unit 13 is disposed outside the rotator 11 with a space from the rotator 11, and is formed in a cylindrical shape so as to cover the periphery of the rotator 11. As will be described later, the magnetic flux flowing out from the convex portions 111a and 111b of the rotating body 11 passes through the heating unit 13. The heating unit 13 is made of a conductive material such as aluminum.

  The heating unit 13 is provided with a pipe 14 through which a heat medium flows (see FIG. 3). In this example, a plurality of flow passages extending in the axial direction are formed inside the heating unit 13, and these are used for the piping 14 through which the heat medium flows. The heating unit 13 and the pipe 14 are thermally connected. For example, in this example, the heating medium is supplied from one end side of the pipe 14 and discharged from the other end side, or on one end side of the pipe 14, a connecting pipe that connects the pipe 14 and another pipe 14 is attached, For example, the heat medium may be supplied from the other end side of the pipe 14 and discharged from the other end side of another pipe 14 through a connecting pipe. That is, in the former case, the flow path is one-way, and in the latter case, the flow path is reciprocal. In the latter case, the heating distance of the heat medium can be increased as compared with the former case.

  Further, a heat insulating material (not shown) may be arranged around the heating unit 13 in order to keep the heating unit 13 warm. For example, in this example, it is possible to provide a heat insulating material in the inner and outer peripheral surfaces of the heating unit 13 and the end surface of the heating unit 13 except for the location where the pipe 14 is disposed. As the heat insulating material, for example, rock wool, glass wool, foamed plastic, brick, ceramics or the like can be used.

  When a heat insulating material is arranged around the heating unit 13, since the distance between the convex portions 111a and 111b of the magnetized rotating body 11 and the heating unit 13 is increased, the magnetic flux passing through the heating unit 13 is reduced. That is, the magnetic field applied to the heating unit 13 decreases. Since the induction heating device 101 uses the coil 12, the original magnetic field strength is high, and if necessary, the energizing current can be increased to increase the magnetic field strength. However, it is easy to obtain performance (heat energy) sufficient to heat the heat medium to a temperature necessary for power generation.

  The stator unit 15 is a cylindrical member disposed on the outer periphery of the heating unit 13, and the heating unit 13 is attached to the inner peripheral surface. The heating unit 13 and the stator unit 15 are fixed so as not to rotate.

  In this example, the stator portion 15 has a cylindrical shape and is made of a magnetic material. For the stator portion 15, for example, a laminated steel plate obtained by laminating silicon steel plates, or a powder magnetic core obtained by applying an insulating coating to the surface of a magnetic powder such as iron powder and press-molding this powder may be used.

  Next, the heating mechanism of the heat medium in the induction heating apparatus 101 will be described in detail.

  In the induction heating device 101, the coil 12 is excited by energizing the coil 12 to generate a magnetic field in the axial direction of the rotating body 11, and the first rotating body 11 a facing one magnetic pole (N pole) of the coil 12 is the N pole. And the second rotating body 11b facing the other magnetic pole (S pole) of the coil 12 is magnetized to the S pole. As a result, the convex portion 111a of the first rotating body 11a is magnetized to the N pole, and the convex portion 111b of the second rotating body 11b is magnetized to the S pole, and in the cross section orthogonal to the axial direction of the rotating body 11, both convex portions 111a 111b are alternately arranged in the circumferential direction of the rotating body 11 in a separated state, so that the polarities of adjacent convex portions of the rotating body 11 are different from each other (see particularly FIG. 3). The magnetic flux that has flowed out of the convex portions 111a and 111b of both the first rotating body 11a and the second rotating body 11b passes through the heating unit 13 disposed outside the rotating body 11 (convex portion). Then, when the rotating body 11 rotates, the magnetic flux passing through the heating unit 13 changes, and an induction current is generated in the heating unit 13, whereby the heating unit 13 is induction-heated and the heat medium in the pipe 14 is heated. Is done.

  Here, in the induction heating device 101, since the polarities of adjacent convex portions of the rotating body 11 are different from each other, the portion facing the convex portion 111a (N pole) of the heating unit 13 and the convex portion 111b (S of the heating unit 13) The direction of the magnetic flux (magnetic field) is different from the portion facing the pole. At a portion (for example, point a in FIG. 3) facing the N-pole convex portion 111a, the direction of the magnetic flux (magnetic field) changes from the inner peripheral side to the outer peripheral side (radial + direction) of the heating unit 13. On the other hand, in the portion facing the convex portion 111b of the S pole (for example, point b in FIG. 3), the direction of the magnetic flux (magnetic field) is from the outer peripheral side of the heating unit 13 to the inner peripheral side (the negative direction in the radial direction).

  FIG. 4 is a diagram schematically showing the temporal change of the magnetic field at point a in FIG. The magnetic field is opposite to the N-pole convex part, and when the distance between the N-pole convex part and the heating part is the narrowest, the strength is maximum in the + direction. On the other hand, when facing the convex portion of the S pole and the distance between the convex portion of the S pole and the heating portion is the narrowest, the strength is maximum in the − direction. That is, the direction and strength of the magnetic field change while periodically reversing as the convex portion rotates and moves due to the rotation of the rotating body 11.

  Further, the number of the convex portions 111a and 111b can be set as appropriate. Here, the period of the magnetic field can be shortened by increasing the number of the convex portions 111a and 111b to some extent. Since the induction heating energy (induction current) is proportional to the frequency of the magnetic field, the heating efficiency can be improved by shortening the period of the magnetic field.

  Furthermore, the coil 12 may be connected to an external power source by pulling out a leader line from an opening 113 formed at the center of the second rotating body 11b, for example. When the coil 12 rotates together with the rotating body 11, for example, a lead wire and an external power source may be connected via a slip ring. Further, a bearing (bearing) may be attached between the connecting member 112 and the coil 12 so that the coil 12 does not rotate even when the rotating body 11 rotates, and the lead wire and the external power source may be connected.

(Embodiment 2)
The induction heating device 102 according to the second embodiment shown in FIGS. 5 and 6 is different from the induction heating device 101 according to the first embodiment shown in FIGS. The explanation will be focused on.

  In the induction heating device 102 according to the second embodiment, the stator unit 15 has a plurality of projections 151 that project centripetally from the cylindrical portion, and each projection 151 is inserted into the heating unit 13. A hole 131 is provided. In this example, the stator portion 15 has 16 protrusions 151, and the protrusions 151 are provided at equal intervals in the circumferential direction. That is, the number of protrusions of the rotating body 11 including the protrusions 111a and 111b is equal to the number of protrusions 151 of the stator portion 15. Further, the protrusion 151 has a quadrangular prism shape that is parallel to the axial direction of the stator portion 15 and has a substantially rectangular cross section cut in a direction orthogonal to the protruding direction.

  The heating mechanism of the heat medium in the induction heating device 102 will be described. When the rotating body 11 rotates, the convex portions 111a and 111b rotate and thereby the magnetic flux passing through the heating portion 13 changes periodically, and heating is performed. Since the induction current is generated in the part 13, the heating part 13 is induction-heated, and the heat medium in the pipe 14 is heated, similar to the induction heating apparatus 101 of the first embodiment. Further, in the induction heating device 102, the rotation of the rotating body 11 causes the distance between the convex portion of the rotating body 11 and the protrusion 151 of the stator portion 15 to be narrow → wide or wide → narrow. The magnetic flux flowing through the magnetic flux changes (see FIGS. 6A and 6B). As a result, an induced electromotive force (counterelectromotive force) is generated in the heating portion around the protrusion and a current flows, whereby the heating portion 13 is heated and the heat medium in the pipe 14 is heated.

  As described above, in the induction heating device 102, when an induced electromotive force is generated, a loop-shaped current path is formed around the protrusion 151 due to the conductive material of the heating part 13 existing around the protrusion 151. For this reason, unlike the induction heating apparatus 101 of the first embodiment, the heat medium is heated using the induced electromotive force.

  Further, since the stator portion 15 (including the protruding portion 151) is made of a magnetic material, a magnetic flux flows through the stator portion 15. And when each convex part 111a, 111b and each projection part 151 oppose, the magnetic flux which flowed out from the convex part 111a of N pole flows into the projection part 151 which opposes this convex part 111a, and the cylindrical shape of the stator part 15 It flows through the portion to the protrusion 151 facing the convex portion 111b of the S pole (the dotted line arrow in FIG. 5B shows an image of the flow of magnetic flux). That is, since a magnetic path is formed from the N-pole convex portion 111a through the stator portion 15 to the S-pole convex portion 111b, the magnetic flux flowing through each protrusion 151 increases.

  In the induction heating device 102 of the second embodiment, the case where the shape of the protrusion 151 in the stator portion 15 is a quadrangular prism having a substantially rectangular cross section cut in a direction orthogonal to the protruding direction is described as an example. It is not limited to this. For example, as shown in FIG. 7, a skew structure in which the protrusions 151 of the stator portion 15 are inclined with respect to the axial direction of the stator portion 15 can be employed. By adopting the skew structure, the cogging torque can be reduced and the rotation of the rotating body 11 can be made smooth. Further, the convex portion of the rotating body 11 may have a skew structure.

  In the induction heating devices 101 and 102 according to the first and second embodiments described above, the flow path is formed inside the heating unit 13, and the case where the heating unit 13 and the pipe 14 are integrally formed has been described as an example. The part 13 and the pipe 14 may be formed separately. In that case, it is preferable that the pipe is also formed of a conductive material. By forming the pipe with a conductive material, the pipe can also be used as a heating unit. Moreover, a heating part and piping may be made into a different body, and piping may be provided in the surface of a heating part. Here, when the pipe is formed of a conductive material and the pipe is also used as a heating unit, for example, the pipe may be attached to the surface of the cylindrical support base in addition to the pipe. At this time, the cylindrical support base may be formed of a material other than the conductive material.

  FIG. 8 is a developed plan view showing an arrangement example of piping when the piping is formed of a conductive material and only the piping is arranged. Here, the case where the pipe 14 is wound around and attached to the inner peripheral surface of the cylindrical stator portion 15 will be described as an example, and FIG. 8 is a developed plan view of the pipe 14 viewed from the inner peripheral surface side of the stator portion 15. It is. In addition, black arrows in FIG. 8 indicate the supply and discharge directions of the heat medium.

  FIG. 8A shows a case where the pipe 14 is configured, and the pipe 14 is bent and disposed on the entire inner peripheral surface of the stator portion 15 so as to meander in the circumferential direction. By causing the pipe 14 to meander, the heating distance of the heat medium can be increased. In this case, the supply-side end portion and the discharge-side end portion of the pipe 14 are displaced by approximately 360 ° in the circumferential direction, that is, the supply-side end portion and the discharge-side end portion are located at substantially the same position in the circumferential direction. Therefore, there is a concern that the heated heat medium discharged from the discharge side end portion is cooled by the heat medium supplied from the supply side end portion, and the heating efficiency is lowered. Therefore, it is preferable that the supply side end portion and the discharge side end portion of the pipe 14 are shifted to some extent in the circumferential direction, for example, by 10 ° or more.

  FIG. 8B shows a case where two pipes 14 are configured. Like the case shown in FIG. 8A, the pipes 14 are arranged in a meandering manner on the entire inner peripheral surface of the stator portion 15. In this case, the supply-side end portion and the discharge-side end portion of the pipe 14 are shifted by approximately 180 ° in the circumferential direction. Further, in this example, the supply side end portions and the discharge side end portions of the adjacent pipes 14 are positioned at substantially the same position in the circumferential direction. Therefore, the heated heat medium discharged from the discharge side end of the pipe 14 is not cooled by the heat medium supplied from the supply side end of another pipe 14.

  FIG. 8 (C) shows a case where four pipes 14 are configured. Like FIG. 8 (B), the pipes 14 are arranged in a meandering manner on the entire inner peripheral surface of the stator portion 15, and adjacent to each other. The supply-side ends of the matching pipes 14 and the discharge-side ends are positioned at substantially the same position in the circumferential direction. In this case, the supply-side end and the discharge-side end of the pipe 14 are displaced by approximately 90 ° in the circumferential direction.

  Thus, when arrange | positioning piping in a meandering state, you may comprise using several piping. Further, in the example shown in FIGS. 8A to 8C, the supply side end and the discharge side end of the pipe 14 are provided on one side of the stator portion 15 in the axial direction. Can be provided on one side or the other side, and the discharge side end can be provided on the other side or one side.

  Further, as in the induction heating device 102 of the second embodiment described above, when the stator portion 15 has the protrusion 151, among the pipes meandering so as to sandwich the protrusion, the bent portion sandwiches the protrusion. A connecting conductor 141 for electrically connecting the pipe parts is separately attached to the side where the pipe parts on the opposite side are separated from each other (see FIG. 8D). You may make it surround the circumference | surroundings of the projection part 151. FIG. As a result, the current accompanying the induced electromotive force generated due to the change in the magnetic flux flowing through the protrusion 151 flows through a loop-shaped current path formed by the pipe 14 and the connection conductor 141. It is possible to prevent leaking outside through 14.

  In addition, when the stator portion has a protrusion, a pipe 14 made of a conductive material may be wound around and attached to the outer periphery of the protrusion 151 as illustrated in FIG. Even with this configuration, an induced electromotive force is generated in the pipe 14 due to a change in the magnetic flux flowing through the protrusion 151, and an electric current flows through the pipe 14 to heat the pipe 14 and heat the heat medium in the pipe 14. Is done. Furthermore, in order to prevent current from leaking to the outside through the pipe 14, the winding start and end ends of the pipe 14 may be electrically connected by a connecting conductor.

  Since the induction heating apparatus according to the embodiment of the present invention described above uses a coil as the magnetic field generating means, it can generate a stronger magnetic field as compared with a conventional apparatus using a permanent magnet. In particular, by adopting a superconducting coil, it is possible to suppress the heat generation of the coil caused by flowing a large current, and it is possible to generate a stronger magnetic field. In addition, since the heating part (pipe) does not rotate, for example, a rotary joint that allows rotation of the pipe to connect the pipe to the supply / discharge pipe that communicates with the pipe and supplies and discharges the heat medium from the outside. There is no need to use a simple connection, and a robust connection can be realized.

<Power generation system>
Next, an example of the overall configuration of the power generation system according to the present invention will be described with reference to FIG. A power generation system P shown in FIG. 10 includes an induction heating device 10, a windmill 20, a heat accumulator 50, and a power generation unit 60. The wind turbine 20 is attached to a nacelle 92 installed at the upper part of the tower 91, and the induction heating device 10 is stored in the nacelle 92. Further, the heat accumulator 50 and the power generation unit 60 are installed in a building 93 built at the lower part (base) of the tower 91. Hereinafter, the configuration of the power generation system P will be described in detail.

  For example, the induction heating apparatus 10 uses the induction heating apparatuses 101 and 102 according to the first and second embodiments. Further, the other end side of the rotating shaft 21 is directly connected to a windmill 20 described later, and wind power is used as power for rotating the rotating body. Here, a case where the heat medium is water will be described as an example.

  The windmill 20 has a structure in which three blades 201 are radially attached to the rotary shaft 21 around a rotary shaft 21 extending in the horizontal direction. In the case of a wind power generation system with an output exceeding 5 MW, the diameter is 120 m or more and the rotation speed is about 10 to 20 rpm.

  Connected to the piping of the induction heating apparatus 10 are a water supply pipe 73 that supplies water to the induction heating apparatus 10 and a transport pipe 51 that sends the water heated by the induction heating apparatus 10 to the regenerator 50. The induction heating device 10 is magnetized so that the convex portions provided on the outer periphery of the rotating body have different polarities alternately in the circumferential direction by energization of the coil, and on the outside of the rotating body by the rotation of the rotating body. When the magnetic flux passing through the arranged heating unit changes, the heating unit is induction-heated to heat the water in the pipe. Since the induction heating apparatus 10 uses a coil as the magnetic field generating means, it can generate a strong magnetic field and can heat water as a heat medium to a high temperature such as 100 ° C. to 600 ° C., for example. In addition, since the induction heating device 10 has a structure in which the heating unit (pipe) does not rotate, it is not necessary to use a rotary joint for connecting the pipe to the transport pipe 51 and the water supply pipe 73. With a simple configuration, a robust connection can be realized.

  In the power generation system P, water is heated to a temperature suitable for power generation (for example, 200 ° C. to 350 ° C.) by the induction heating device 10 to generate high-temperature and high-pressure water. The high-temperature high-pressure water is sent to the regenerator 50 through a transport pipe 51 that connects the induction heating device 10 and the regenerator 50. The heat accumulator 50 stores the heat of the high-temperature and high-pressure water sent through the transport pipe 51, and supplies steam necessary for power generation to the power generation unit 60 using a heat exchanger. Note that steam may be generated by the induction heating device 10.

  As the heat accumulator 50, for example, a steam accumulator, a sensible heat type using a molten salt or oil, or a latent heat type heat accumulator using a phase change of a molten salt having a high melting point can be used. Since the latent heat type heat storage method stores heat at the phase change temperature of the heat storage material, the heat storage temperature range is generally narrower than that of the sensible heat type heat storage method, and the heat storage density is high.

  The power generation unit 60 has a structure in which a steam turbine 61 and a generator 62 are combined. The steam turbine 61 is rotated by the steam supplied from the heat accumulator 50, and the generator 62 is driven to generate power.

  The high-temperature high-pressure water or steam sent to the regenerator 50 is cooled by the condenser 71 and returned to the water. After that, it is sent to the pump 72 and is circulated by being made into high-pressure water and sent to the induction heating device 10 through the water supply pipe 73.

  According to this power generation system P, it is possible to generate rotational energy by using renewable energy (eg, wind power) as power, generate heat, and store the heat in a heat accumulator to generate electricity, so that an expensive storage battery is not used. However, stable power generation according to demand can be realized. Further, it is not necessary to provide a speed increaser unlike the conventional wind power generation system, and it is possible to avoid a gearbox trouble. Furthermore, by supplying the heat of the heat medium to the power generation unit installed in the lower part (base) of the tower, for example, by a transport pipe, there is no need to store the power generation part in the nacelle, and the nacelle installed in the upper part of the tower is made small -It can be reduced in weight.

  In the power generation system described above, the case where water is used as the heat medium has been described as an example. However, a liquid metal having a higher thermal conductivity than water may be used as the heat medium. An example of such a liquid metal is liquid metal sodium. When using a liquid metal as the heat medium, for example, the liquid metal is used as the primary heat medium that receives heat from the heating unit, and the secondary heat is transmitted through the heat exchanger using the heat of the liquid metal sent through the transport pipe. It is conceivable that the medium (water) is heated to generate steam.

  In addition, when oil, liquid metal, molten salt, or the like having a boiling point of over 100 ° C. at normal pressure is used as the heating medium, the heating medium in the piping when heated to over 100 ° C. compared to water It is easy to suppress an increase in internal pressure due to vaporization.

(Example 1)
Using a simulation model 1000 as illustrated in FIG. 11, the total cost of the initial cost and the running cost when the superconducting coil is used as the coil 1200 and the copper coil is estimated.

  The simulation model 1000 has a structure in which a coil 1200 is mounted on a C-shaped iron core 1100 having a magnetic gap. The iron core 1100 has a cross section of 400 mm × 500 mm and a gap distance of 100 mm.

  The cost was estimated under the following conditions. The operation time was 4800 hours per year (200 days x 24 hours), and the electricity rate was calculated as 15 yen per kilowatt hour. In addition, considering the power consumption of the coil, when using a superconducting coil, also consider the operating power of the cooling system. When using a copper coil, the water cooling system and the air cooling system are used. Considering the operating power. A current that generates a 1T magnetic field in the magnetic gap was passed through the coil.

  The result of trial calculation of the total cost is shown in FIG. In FIG. 12, the total cost of the superconducting coil is indicated by a solid line, the total cost of a water-cooled copper coil (water-cooled copper coil) is indicated by a broken line, and the total cost of an air-cooled copper coil (air-cooled copper coil) is indicated by a dotted line. From this result, when a superconducting coil is used, the initial cost is higher than that of a water-cooled copper coil, but since the power consumption is small, the running cost is low and the total cost is about 3 years. It turns out that it reverses. That is, when the superconducting coil is used as the magnetic field generating means of the induction heating device in the power generation system of the present invention, the cost effectiveness is higher and the power generation cost can be suppressed.

Next, under the above conditions, the weight of the coil when the superconducting coil was used as the coil 1200 and the copper coil in the simulation model 1000 of FIG. 11 was estimated. However, for water-cooled copper coils, the current density is 10 A / mm ² , for air-cooled copper coils, the current density is 1 A / mm ^{2. For} superconducting coils, the weight of the cooling system is also calculated. In consideration of the water-cooled copper coil, the weight of the water-cooled system was also taken into consideration.

  As a result of calculating the coil weight, the weight of the superconducting coil was 200 kg, the weight of the water-cooled copper coil was 200 kg, and the weight of the air-cooled copper coil was 2000 kg. From this result, it can be seen that when a superconducting coil is used, it can be made smaller and lighter than an air-cooled copper coil. That is, when the superconducting coil is used as the magnetic field generating means of the induction heating device in the power generation system of the present invention, the induction heating device can be reduced in size and weight and can be easily placed in, for example, the nacelle. Become. Furthermore, when a copper coil is used as the magnetic field generating means of the induction heating device, an iron core is required to strengthen the magnetic field, and the iron core must be enlarged to suppress the magnetic flux saturation of the iron core. Compared to a coil, the induction heating device cannot be avoided in size and weight.

  Furthermore, recently, the influence on the human body due to the low frequency noise accompanying the rotation of the windmill has become a problem. Measures for reducing low-frequency noise generated from a windmill are being studied not only in Japan but also overseas, and it is known that low-frequency noise can be suppressed by rotating the windmill at a low speed. In the heating mechanism of the induction heating device in the power generation system of the present invention, the heat energy obtained when the rotating body is rotated at a low speed decreases, but a strong magnetic field is generated by adopting a superconducting coil as the magnetic field generating means of the induction heating device. Therefore, sufficient heat energy can be obtained even at a low speed.

  Note that the present invention is not limited to the above-described embodiment, and can be modified as appropriate without departing from the gist of the present invention. For example, it is possible to appropriately change the shapes of the rotating body and the stator part, and to appropriately change the material forming the rotating body and the stator part.

  The power generation system of the present invention can be suitably used in the field of power generation using renewable energy.

10, 101-102 Induction heating device P Power generation system
11 Rotating body
11a First rotating body 11b Second rotating body
111a, 111b Convex 112 Connecting member 113 Opening
12 coil (superconducting coil)
13 Heating part 131 Hole
14 Piping 141 Connecting conductor
15 Stator 151 Projection
21 Rotation axis
20 Windmill 201 Wings
50 Heat storage unit 51 Transport pipe
60 Power generation section 61 Steam turbine 62 Generator
71 Condenser 72 Pump 73 Water supply pipe
91 Tower 92 Nasser 93 Building
1000 simulation model 1100 iron core 1200 coils

Claims (5)

An induction heating device that heats the heat medium; and a power generation unit that converts heat of the heat medium into electric energy,
The induction heating device includes:
A rotating body formed by combining at least a part of a first rotating body formed of a magnetic material and having a rotating shaft and a second rotating body connected to the first rotating body;
The first rotating body and the second rotating body are arranged between the first rotating body and the second rotating body so that one magnetic pole and the other magnetic pole face each other, and in the axial direction of the rotating body A coil for generating a magnetic field;
A heating unit that is at least partially formed of a conductive material and is arranged outside the rotating body and spaced from the rotating body;
A pipe provided in the heating unit and through which the heat medium flows ;
A stator portion disposed on the outer periphery of the heating portion and made of a magnetic material ,
Both the first rotating body and the second rotating body are formed with at least one protrusion protruding in the radial direction of the rotating body, and the both protrusions are displaced in the circumferential direction. Extended toward the other side in a state and separated from each other ,
The stator portion has a cylindrical shape, and has a protruding portion that projects centripetally from the cylindrical portion,
The heating unit is attached to an inner peripheral surface of the stator unit, and has a hole through which the protrusion is inserted . The power generation system according to claim 1 , wherein the coil is a superconducting coil. The rotating shaft is connected to a windmill;
The power generation system according to claim 1 , wherein wind power is used as power for rotating the rotating body. The power generation system according to any one of claims 1 to 3, wherein aluminum is used for the heating unit. The power generation system according to any one of claims 1 to 4, further comprising a heat accumulator that stores heat of the heat medium heated by using the induction heating device.

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