Rotary heat generator, electrothermal conversion device, and heat storage system

Abstract

To increase an efficiency of conversion into a thermal energy while downsizing a device.SOLUTION: An electrothermal conversion device (10) includes: a rotary heat generator (20); and an electric motor (11) that rotates a rotor (22) via a shaft (12). The rotary heat generator includes: a stator (21) configured by holding a stator winding (26) in a cylindrical stator core (25) along a rotation direction; the rotor (22) provided with a heating conductor (32) disposed inside the stator (21); and a flow path (36) formed between the stator and the rotor. A heat medium (M) flows through a flow path. The heating conductor is formed of a massive soft magnetic conductor.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a rotary heating machine having a stator and a rotor, an electrothermal converter, and a heat storage system. [Background technology]

[0002] Patent Document 1 discloses a heat generating device that includes an electric motor connected to a power grid and a heat generating machine that converts the rotational force of the electric motor into heat. In the heat generating machine, a magnetic flux generating part rotates together with a rotating part, and as the magnetic flux generating part moves relative to the heat generating part, the magnetic flux passing through the entire circumference of the heat generating part changes, and the magnetic field applied to the heat generating part changes periodically. This generates eddy currents in the heat generating part, which generates heat, and the heat medium is heated by the heat. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-097523 [Non-patent literature]

[0004] [Non-Patent Document 1] Hiroki Saito, Tomofumi Miura, Satoshi Imamori, and Toru Okazaki, "Verification of Heat Conversion Efficiency of a Rotary Heat Generator Using a Non-Seal Pump," 2023 National Convention of the Institute of Electrical Engineers of Japan, March 2023, 7-005 Summary of the Invention [Problem to be solved by the invention]

[0005] Although such heat generating devices can be made smaller than conventional electrothermal conversion devices that use resistance heaters, etc., there is a need to improve the conversion efficiency of converting the mechanical energy that rotates the rotor into thermal energy. Non-Patent Document 1 describes that in order to improve such conversion efficiency, the amount of heat generated by the stator should be relatively low, but does not disclose any technology for achieving this, and there is a need for technology to improve the efficiency of conversion into thermal energy.

[0006] The present invention has been made in consideration of the above-mentioned circumstances, and aims to provide a rotating heating machine, an electrothermal conversion device, and a heat storage system that can increase the efficiency of conversion to thermal energy while miniaturizing the device. [Means for solving the problem]

[0007] The rotary heating machine of the present invention comprises a stator formed by a cylindrical iron core along the direction of rotation and having windings held thereon, a rotor having a heating conductor disposed inside the stator, and a flow path formed between the stator and the rotor, through which a heat medium flows, and is characterized in that the heating conductor is formed from a block of soft magnetic conductor.

[0008] The electrothermal converter of the present invention is characterized by including the rotary heating machine and an electric motor that rotates the rotor via a shaft.

[0009] The heat storage system of the present invention is characterized by comprising the electrothermal conversion device, a heat storage device that stores the heat medium and supplies and recovers the heat medium to the rotating heating machine, and a heat utilization device that utilizes the heat of the heat medium supplied from the heat storage device. [Effects of the Invention]

[0010] According to the present invention, the rotor's heating conductor is a massive soft magnetic conductor, which increases eddy current loss while also generating hysteresis loss in the rotor. This allows the proportion of the rotor's heat generation to be increased and the proportion of the stator's heat generation to be reduced in the overall heat generation of the rotary heating machine. Therefore, since heat transfer to the heat medium in a rotary heating machine is mainly from the rotor, increasing the proportion of the rotor's heat generation can improve the efficiency of conversion to thermal energy. Furthermore, the rotation of the rotor can stir the heat medium, suppressing temperature increases in the rotor, etc., and enabling the rotary heating machine to be made smaller. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a schematic configuration diagram of an electrothermal conversion device according to an embodiment. [Figure 2] 1 is a cross-sectional view of a rotary heating machine according to an embodiment. [Figure 3] FIG. 3 is a schematic cross-sectional view taken along an arrow A in FIG. 2. [Figure 4] 1 is a schematic configuration diagram of a heat storage system according to an embodiment. [Figure 5] FIG. 3 is a cross-sectional view similar to FIG. 2 of a rotary heating machine according to a modified example. [Figure 6] FIG. 10 is a cross-sectional view similar to FIG. 2 of a rotary heating machine according to another modified example. [Figure 7] FIG. 2 is a model diagram for simulation of the rotating heating machine of the first embodiment. [Figure 8] FIG. 10 is a model diagram for simulation of the rotating heating machine of the second embodiment. [Figure 9] FIG. 10 is a model diagram for simulation of the rotating heating machine of the third embodiment. [Figure 10] 1 is a graph showing the simulation results of Examples 1 to 3 and a conventional example. [Figure 11] 10 is a graph showing the simulation results of Examples 4 to 14. DETAILED DESCRIPTION OF THE INVENTION

[0012] An electrothermal conversion device, a rotary heating machine, and a heat storage system according to an embodiment of the present invention will be described in detail below with reference to the accompanying drawings. The present invention is not limited to the following embodiment, and can be modified as appropriate without departing from the spirit and scope of the present invention. For ease of explanation, some components may be omitted from the following drawings. Furthermore, in this specification and claims, "inner," "inside," and "inward" refer to directions toward or toward the center of rotation of the rotary heating machine, and "outer," "outward," and "outward" refer to the opposite side. Furthermore, a "circumferential direction" refers to a direction parallel to the rotation direction of the rotary heating machine, and a "radial direction" refers to a direction in which the diameter of a circle aligned with the circumferential direction extends.

[0013] Fig. 1 is a schematic diagram of an electrothermal converter according to an embodiment. As shown in Fig. 1, the electrothermal converter 10 includes an electric motor 11 and a rotary heating machine 20 connected to the electric motor 11 via a shaft 12.

[0014] The electric motor 11 may be a permanent magnet type electric motor or an induction motor, or may be any other type of electric motor, and can be selected taking into consideration efficiency, controllability, and the like.

[0015] Fig. 2 is a cross-sectional view of a rotary heating machine according to an embodiment. Fig. 2 shows a cross section perpendicular to the central axis of rotation C of the rotary heating machine 20; in other words, the central axis of rotation C extends in a direction perpendicular to the plane of the paper on which Fig. 2 is drawn. Fig. 2 also shows the upper half of the rotary heating machine 20, omitting the lower half.

[0016] As shown in FIG. 2, the rotary heating machine 20 includes a stator 21, a rotor 22, and a frame .

[0017] The stator 21 is configured to include a cylindrical stator core (iron core) 25 centered on the central axis of rotation C, and a stator winding (winding) 26 held by the stator core 25.

[0018] The stator core 25 includes a yoke portion 28 formed in an annular shape centered on the central axis of rotation C, and a plurality of teeth 29 protruding from the inner peripheral surface of the yoke portion 28 toward the rotor 22. The plurality of teeth 29 are formed side by side at predetermined intervals in the circumferential direction of the yoke portion 28. Therefore, slots 30 are formed between adjacent teeth 29 in the circumferential direction of the yoke portion 28. The teeth 29 and slots 30 are formed in a shape that extends parallel to the central axis of rotation C.

[0019] The tooth portion 29 includes a tip portion 29a that forms the rotor 22 side, and a base portion 29b that connects the tip portion 29a to the inner circumferential surface of the yoke portion 28. The base portion 29b forms the area of ​​the tooth portion 29 other than the tip portion 29a. The base portion 29b has a shape that extends approximately parallel to the radial direction, and the circumferential width of the base portion 29b is constant at any radial position. Therefore, the forming surfaces on both circumferential sides of the base portion 29b are formed approximately parallel to the radial direction. On the other hand, the tip portion 29a is formed in a flange shape that protrudes on both circumferential sides from the base portion 29b. Note that the tip portion 29a forms an area that comes into contact with the heat medium M flowing through a flow path 36, which will be described later, and may include an area closer to the outer side than the flange-shaped area.

[0020] In the stator core 25, the tip portions 29a of the teeth 29 are made of a lump of soft magnetic conductor. Here, "lump" means that it is made of only the target material (here, the soft magnetic conductor), rather than a structure in which the material is laminated with an insulating coating, such as laminated steel sheets, or a structure in which the grain surfaces are coated with an insulating coating and then pressed, such as a powder core. The soft magnetic conductor can be, for example, ordinary iron, such as structural steel.

[0021] Furthermore, in stator core 25, bases 29b of teeth 29 are made of a laminated steel plate, such as electromagnetic steel plates, or a soft magnetic nonmetal. Here, the soft magnetic nonmetal is not limited to ceramic materials such as ferrite cores, but may be any soft magnetic material that has been processed to have lower conductivity than metal, such as a powder magnetic core made by insulating-coating soft magnetic metal powder and then press-molding it. Yoke 28 of stator core 25 may also be made of the same material as base 29b.

[0022] Stator winding 26 is wound around teeth 29, for example, in a distributed manner to form three phases (U phase, V phase, and W phase) around teeth 29. Stator winding 26 is not limited to distributed winding, and can also be concentrated winding.

[0023] The stator core 25 can be formed of a magnetic material such as silicon steel plate. Furthermore, since the stator winding 26 is placed in a high-temperature heat medium (described later) and used in a high-temperature environment, an example of the stator winding 26 that can be used is an ultra-heat-resistant winding having a ceramic insulating layer. When the operating temperature is low, the stator winding 26 can also be made of an enameled wire such as a polyamide-imide copper wire or a polyimide copper wire.

[0024] The rotor 22 includes a portion of the shaft 12 described above and a heating conductor 32 fixed to the outer periphery of the portion of the shaft 12 and disposed inside the stator 21. The rotor 22 is rotated by the electric motor 11 via the shaft 12. The heating conductor 32 is made of the above-described massive soft magnetic conductor, similar to the tip portion 29a.

[0025] The heating conductor 32 has a cylindrical outer peripheral surface on which an uneven portion 34 is formed. The uneven portion 34 includes a plurality of recesses 34b arranged at predetermined intervals in the circumferential direction of the heating conductor 32 and a plurality of protrusions 34a formed by the recesses 34b between two adjacent recesses 34b on both sides in the circumferential direction. Thus, the uneven portion 34 is formed such that the recesses 34b and the protrusions 34a are alternately arranged in the circumferential direction. The recesses 34b and the protrusions 34a are formed in a shape extending parallel to the central axis C of rotation. In FIG. 2, the number of recesses 34b formed in the rotor 22 is smaller than the number of slots 30 formed in the stator core 25, but this is not limited thereto. For example, the number of recesses 34b may be greater than or equal to the number of slots 30. The number of recesses 34b will also be compared in the examples described below.

[0026] The frame 23 is formed in a cylindrical shape, and the stator 21 is disposed on the inner periphery side.

[0027] The rotary heating machine 20 further includes a flow path 36 through which the heat transfer medium M flows. The flow path 36 is formed in the gap (space) between the inner circumferential side of the stator 21 and the outer circumferential side of the rotor 22. In this embodiment, a chemically inert nitrate-based molten salt is used as the heat transfer medium M. An example of a nitrate-based molten salt is a mixed salt of NaNO3 and KNO3. The heat transfer medium M receives heat generated by the heating conductor 32 and is heated, and a fluid other than molten salt may be used as long as it can be stably used in a high-temperature state after heating.

[0028] FIG. 3 is a schematic cross-sectional view taken along the arrow A in FIG. 2. As shown in FIG. 3, a bearing 38 that rotatably supports the shaft 12 is provided inside the frame 23. The frame 23 is provided with a cylindrical partition wall 40 (not shown in FIG. 2) that accommodates not only a portion of the shaft 12 and the heating conductor 32 but also the heat medium M. The partition wall 40 defines an accommodation space 39 therein, and the accommodation space 39 communicates with a flow path 36 that extends parallel to the central axis of rotation C between the partition wall 40 and the rotor 22, which is located inside the stator 21. The partition wall 40 prevents the heat medium M from contacting the stator 21. The frame 23 is provided with an inlet portion 23a that supplies the heat medium M to the accommodation space 39 from the lower left side in FIG. 3 and an outlet portion 23b that discharges the heat medium M from the upper right side in FIG. 3, and the heat medium M flows between the frame 23 and the heat storage device 3, which will be described later.

[0029] The electrothermal converter 10 can be used in a heat storage system 1 shown in Fig. 4. Fig. 4 is a schematic configuration diagram of a heat storage system according to an embodiment. As shown in Fig. 4, the heat storage system 1 includes a power generation device 2 and a heat storage device 3 in addition to the electrothermal converter 10.

[0030] The thermal storage system 1 is connected to an electric power grid L, and is supplied with electric power from a power source G via the electric power grid L. The electric power grid L is a facility that supplies electric power generated by the power source G to a consumer D. The power source G is made up of a group of generators connected to the electric power grid L. The power source G includes various types of power sources, such as general power sources such as thermal power generation, nuclear power generation, and hydroelectric power generation, as well as renewable energy power sources represented by solar power generation and wind power generation.

[0031] When surplus power occurs in the power grid L, a control unit (not shown) controls the electrothermal converter 10 to operate, and the electrothermal converter 10 heats the heat medium M to convert electrical energy into thermal energy. The heated high-temperature heat medium M is stored in the heat storage device 3. When no surplus power is occurring in the power grid L, the power generator 2 is controlled to generate power using the high-temperature heat medium M supplied from the heat storage device 3 in accordance with the power demand, and the power is supplied to the power grid L.

[0032] The power generation device 2 is a device that generates electricity by utilizing the heat of the heat medium M supplied from the heat storage device 3, and is connected to the power grid L. The power generation device 2 can be a known device, and is configured, for example, with a steam turbine and a generator. Note that in the heat storage system 1, the power generation device 2 may be changed to another heat utilization device that utilizes the heat of the heat medium M.

[0033] The heat storage device 3 can be exemplified by a configuration including a high-temperature tank 3a that stores a relatively high-temperature heat medium M and a low-temperature tank 3b that stores a relatively low-temperature heat medium M. In the heat storage device 3, the heat medium M in the low-temperature tank 3b is supplied to the electrothermal converter 10 (rotary heating machine 20), and the heat medium M that has been heated to a high temperature by the electrothermal converter 10 (rotary heating machine 20) is recovered (sent) to the high-temperature tank 3a and stored therein. In addition, the heat medium M in the high-temperature tank 3a is supplied to the power generator 2, and the heat medium M that has been cooled by heat utilization by the power generator 2 is supplied to the low-temperature tank 3b and stored therein.

[0034] Next, the conversion of electrical energy into thermal energy in the electrothermal converter 10 will be described.

[0035] In the electrothermal converter 10, power is supplied from a power grid L to the electric motor 11, which rotates the rotor 22 of the rotary heating machine 20 via the shaft 12, converting electrical energy into mechanical energy. At this time, the electric motor 11 is variably controlled via, for example, an inverter.

[0036] In the electrothermal converter 10, power is supplied from the power grid L to the stator winding 26 of the rotary heating machine 20, and a magnetic field is generated in the stator winding 26 by three-phase AC. At this time, the amount of power supplied to the rotary heating machine 20 is controlled, for example, via an inverter. The magnetic field generated by the stator winding 26 is applied to the heating conductor 32 of the rotor 22.

[0037] The heating conductor 32 rotates with the rotation of the shaft 12 while a magnetic field is applied from the stator winding 26. This changes the density of the magnetic flux passing through the heating conductor 32, which generates eddy current loss and hysteresis loss, causing the heating conductor 32 to heat up. As the heating conductor 32 generates heat, heat is transferred from the heating conductor 32 to the heat medium M flowing through the flow path 36, causing the heat medium M to heat up. As a result, the mechanical energy that rotates the rotor 22 is converted into thermal energy for the heat medium M.

[0038] In the above embodiment, the heating conductor 32 is a block conductor, which allows a larger amount of eddy current to flow than in a conductor with a laminated structure, thereby increasing the eddy current loss in the heating conductor 32 and increasing the amount of heat generated in the rotor 22. Moreover, since the heating conductor 32 has soft magnetic properties, the density of the magnetic flux passing through the heating conductor 32 is more likely to change, which increases the hysteresis loss in the heating conductor 32 and increases the amount of heat generated in the rotor 22.

[0039] Increasing the heat generation amount of the rotor 22 in this way makes it possible to increase the proportion of the heat generation amount of the rotor 22 relative to the total heat generation amount of the entire rotary heating machine 20, and to decrease the proportion of the heat generation amount of the stator 21. Therefore, in the rotary heating machine 20, heat transfer to the heat medium M is mainly performed from the rotor 22, and therefore increasing the proportion of the heat generation amount of the rotor 22 makes it possible to increase the efficiency of conversion to thermal energy.

[0040] Furthermore, the rotation of the rotor 22 can stir the heat medium M flowing through the flow path 36, preventing the heat medium M in the rotor 22 or flow path 36 from becoming locally hot. This prevents the heat medium M from becoming so hot that it vaporizes or decomposes, while increasing the amount of thermal energy received by the entire heat medium M, allowing for a more compact device compared to conventional devices using resistance heaters, etc. Furthermore, because the heating conductor 32 is a block conductor, the rotor 22 can be made from a single material and a single part. This prevents an increase in the number of parts and a complex structure, reducing the manufacturing burden.

[0041] Moreover, because the tip portions 29a of the teeth 29 in the stator 21 are made of a solid soft magnetic conductor, the eddy current loss and hysteresis loss can be increased at the tip portions 29a of the stator 21 that come close to the heat medium M, just like the heating conductors 32 of the rotor 22. This increases the amount of heat transferred from the tip portions 29a of the teeth 29 to the heat medium M, further improving the efficiency of conversion to thermal energy. Furthermore, the base portions 29b of the teeth 29 are made of laminated steel plate or a soft magnetic nonmetal; in other words, the majority of the teeth 29 can be made of a laminated steel plate or a soft magnetic nonmetal with low iron loss. This prevents an increase in the amount of thermal energy dissipated to the outside from the stator 21, thereby improving the efficiency of conversion to thermal energy.

[0042] Furthermore, the provision of the uneven portion 34 on the outer peripheral surface of the heating conductor 32 allows for more complex changes in the magnetic flux passing through the heating conductor 32, which is a soft magnetic conductor. This increases the eddy current loss and hysteresis loss generated by the heating conductor 32, thereby increasing the proportion of the heat generated by the rotor 22 and further improving the efficiency of conversion to thermal energy. Furthermore, the uneven portion 34 is formed by alternating protrusions 34a and recesses 34b in the circumferential direction of the heating conductor 32, allowing the magnetic flux to be changed satisfactorily at a predetermined cycle by the rotation of the heating conductor 32, contributing to increasing the proportion of the heat generated by the rotor 22.

[0043] Furthermore, since the electrothermal conversion device 10 is configured with the above-mentioned rotary heating machine 20, the electrical energy supplied to the electric motor 11 can be efficiently converted into thermal energy via mechanical energy that rotates the shaft 12.

[0044] Furthermore, since the heat storage system 1 is configured to include the above-described rotary heating machine 20, it is possible to store surplus power such as renewable energy and effectively utilize the stored surplus power during times of power shortage.

[0045] The present invention is not limited to the above-described embodiment, and can be modified in various ways. In the above-described embodiment, the size and shape shown in the accompanying drawings are not limited to these, and can be modified as appropriate within the scope of the effects of the present invention. In addition, the present invention can be modified as appropriate without departing from the scope of the object of the present invention.

[0046] In the above embodiment, the teeth 29 have a shape with flange-shaped tip portions 29a. However, this is not limiting and the configuration can be modified, for example, as shown in FIG. 5. FIG. 5 is a cross-sectional view similar to FIG. 2 of a rotary heating machine according to a modified example. As shown in FIG. 5, the teeth 29 of the modified example have a constant circumferential width at any radial position, and the tip portions 29a of the above embodiment are shaped so that they do not protrude on both circumferential sides. By providing the teeth 29 in this shape, the heating conductor 32 can be subjected to more rapid magnetic field changes than in a configuration with tip portions 29a. In other words, harmonic components are superimposed on the magnetic flux density waveform in the rotor 22, which increases the amount of heat generated by the rotor 22. This increases the proportion of heat generated by the rotor 22 and further improves the efficiency of conversion to thermal energy.

[0047] Furthermore, the uneven portion 34 in the above embodiment is not limited to the above-described convex portions 34a and concave portions 34b. For example, various modifications are possible, such as changing the circumferential width depending on the number of convex portions 34a and concave portions 34b formed, making the convex portions 34a and concave portions 34b curved, or forming the convex portions 34a in a protruding shape and distributing them evenly.

[0048] The heating conductor 32 may have a smooth cylindrical outer peripheral surface without forming the uneven portion 34. However, forming the uneven portion 34 is advantageous in that it makes the change in the magnetic flux passing through the heating conductor 32 a complex change, thereby increasing the amount of heat generated by the rotor 22.

[0049] Furthermore, the tip portions 29a of the teeth 29 may be made of the same material as the base portions 29b. However, using a lump-shaped soft magnetic conductor for the tip portions 29a of the teeth 29, as in the above embodiment, is advantageous in that it increases the amount of heat generated by the tip portions 29a.

[0050] Furthermore, the stator core 25 in the stator 21 is not limited to a cylindrical shape, and may have other cylindrical shapes along the direction of rotation, for example, the outer circumferential shape in a cross section perpendicular to the central axis of rotation C may be a polygonal shape such as a square.

[0051] Furthermore, the frame 23 may be omitted as long as the rotary heating machine 20 can function in the same manner as in the above embodiment.

[0052] Furthermore, in the above embodiment, the circumferential width of base 29b of teeth 29 is constant, but this is not limited to this and can be modified, for example, as shown in Figure 6. Figure 6 is a cross-sectional view similar to Figure 2 of a rotary heating machine according to another modified example.

[0053] 6, the circumferential width of bases 29b of teeth 29 increases outward, and the circumferential width is constant at any radial position in slot 30. By making the width of slot 30 constant in this way, square wire can be used for stator winding 26, which increases the density of stator winding 26 within slot 30 and allows for a relative reduction in loss in stator core 25. [Example]

[0054] Next, a simulation performed to confirm the heat generation amount of the rotating heating machine based on the structure of the above embodiment will be described with reference to Figs. 7 to 10. Fig. 7 is a model diagram for simulation of the rotating heating machine of Example 1. Fig. 8 is a model diagram for simulation of the rotating heating machine of Example 2. Fig. 9 is a model diagram for simulation of the rotating heating machine of Example 3. Fig. 10 is a graph showing the simulation results of Examples 1 to 3 and the conventional example. Like Fig. 2, the model diagrams of Figs. 7 to 9 show the upper half of a cross section perpendicular to the central axis of rotation C of the rotating heating machine 20, and the same reference numerals are used to designate components common to the above embodiment.

[0055] In Example 1, a model diagram of the rotary heating machine 20 shown in FIG. 7 was created. In Example 1, the stator 21 and the rotor 22 were configured in the same manner as in the above-described embodiment, but had the shape shown in FIG. 7. More specifically, in Example 1, the number of slots 30 in the stator 21 and the number of recesses 34b in the rotor 22 were both 24, the same number. Since FIG. 7 illustrates the upper half of the rotary heating machine 20, 12 slots 30 and 12 recesses 34b are shown. In Example 1, the tip portions 29a of the teeth 29 were made of the same material as the base portions 29b, and the partition wall 40 was omitted.

[0056] In Example 2, a model diagram of the rotary heating machine 20 shown in Fig. 8 was created, and in Example 3, a model diagram of the rotary heating machine 20 shown in Fig. 9 was created. In Examples 2 and 3, the stator 21 had the same configuration as Example 1, but the number of recesses 34b formed in the rotor 22 was increased and the width of the recesses 34b was reduced. Specifically, the number of recesses 34b formed in Example 2 was 34, and the number of recesses 34b formed in Example 3 was 30.

[0057] In the conventional example, the configuration of rotor 22 is changed from that of Example 2, and the rotor is configured similar to that of a squirrel-cage induction machine. More specifically, the rotor of the conventional example is configured using laminated steel plates made of laminated electromagnetic steel sheets, etc. Furthermore, the rotor of the conventional example is configured such that multiple rod-shaped conductors are arranged instead of the recesses 34b of Example 2, and both ends of each conductor are electrically connected by end rings.

[0058] In Examples 1 to 3 and the conventional example, a simulation was performed on the heat generation amounts of the stator 21 and the rotor 22 under the same conditions of the rotation speed of the rotor 22 and the voltage applied to the stator winding 26. The results of the simulation are shown in the graph of Fig. 10. Here, the graph of Fig. 10 shows the heat generation amounts divided into the eddy current loss of the stator 21, the hysteresis loss of the stator 21, the hysteresis loss of the rotor 22, and the joule loss of the rotor 22. The joule loss of the rotor 22 includes the eddy current loss described above as well as the joule loss that occurs when the rotor 22 functions as a winding.

[0059] As is clear from Fig. 10, the total amount of heat generated is greater in Examples 1 to 3 than in the conventional example. Furthermore, while the amount of heat generated by the stator 21 is roughly the same in Examples 1 to 3 and the conventional example, the amount of heat generated by the rotor 22 is greater in Examples 1 to 3 than in the conventional example. This shows that by forming the rotor 22 from a massive soft magnetic conductor, as in Examples 1 to 3, it is possible to increase Joule loss (eddy current loss) and hysteresis loss, thereby increasing the proportion of the heat generated by the rotor 22 compared to the stator 21 and improving the efficiency of conversion to thermal energy.

[0060] Furthermore, the joule loss of rotor 22 in Example 1 is greater than that of Examples 2 and 3. As a result, by making the number of slots 30 formed in stator 21 and the number of recesses 34b formed in rotor 22 the same as in Example 1, the efficiency of conversion to thermal energy can be improved compared to configurations in which the number of slots 30 and the number of recesses 34b are different.

[0061] Next, a simulation performed to confirm the heat generation amount of the rotary heating machine based on the structure of the modified example shown in Fig. 5 will be described with reference to Fig. 11. Fig. 11 is a graph showing the simulation results of Examples 4 to 14.

[0062] In the simulations of Examples 4 to 14, a model diagram of a rotary heating machine configured similarly to the modified example shown in FIG. 5 was created, except that the number of slots 30 in the stator 21 and the number of recesses 34b in the rotor 22 were changed. In Examples 4 to 14, the number of slots 30 in the stator 21 was set to 24. In Example 4, the number of recesses 34b in the rotor 22 was set to 20, and in Examples 5 and onward, the number of recesses 34b was increased by two compared to the immediately preceding Examples. Therefore, in Example 14, the number of recesses 34b was set to 40. In Examples 4 to 14, the stator core 25, including the entire teeth portion 29, was made of the same material, and the partition walls 40 were omitted.

[0063] In Examples 4 to 14, a simulation of the heat generation amount of the stator 21 and the rotor 22 was performed under the same conditions as in the simulations of Examples 1 to 3 and the conventional example, with respect to the rotation speed of the rotor 22 and the voltage applied to the stator winding 26. The results of the simulation are shown in the graph of Fig. 11. Here, in the graph of Fig. 11, as in the graph of Fig. 10, the heat generation amount is shown divided into the eddy current loss of the stator 21, the hysteresis loss of the stator 21, the hysteresis loss of the rotor 22, and the Joule loss of the rotor 22.

[0064] 10 and 11, the total amount of heat generated in Examples 4 to 14 is more than twice as much as that in Examples 1 to 3. This shows that by forming the circumferential width of the teeth 29 to be constant and making the heating conductor 32 subject to a steeper change in the magnetic field, as in the modified example of Fig. 5 adopted in Examples 4 to 11, the amount of heat generated by the rotor 22 is increased, and the proportion of the heat generated by the rotor 22 is increased, thereby improving the efficiency of conversion to thermal energy.

[0065] 11, the amount of heat generated by the rotor 22 is greater in Examples 8 to 11 than in Examples 4 to 7, and it can be seen that from Example 8 onwards, that is, when the number of recesses 34b is 28 or more, the amount of heat generated by the rotor 22 increases significantly. In all of Examples 4 to 11, the number of slots 30 formed in the stator 21 is 24, and the value obtained by dividing the number of recesses 34b formed in Example 8 (28) by this number (24) is 7 / 6. Therefore, when the value obtained by dividing the number of recesses 34b formed by the number of slots 30 is 7 / 6 or more, the amount of heat generated by the rotor 22 can be increased, and therefore the proportion of the heat generated by the rotor 22 can be increased, thereby improving the efficiency of conversion to thermal energy. [Explanation of symbols]

[0066] 1: Heat storage system 2: Power generation equipment 3: Heat storage device 3a: High temperature tank 3b: Low temperature tank 10: Electrothermal conversion device 11: Electric motor 12: Shaft 20: Rotating heating machine 21: Stator 22: Rotor 23: Frame 23a: Entrance section 23b:Exit part 25: Stator core (iron core) 26: Stator winding (winding) 28:Yoke 29: Teeth 29a:Tip 29b: base 30: Slot 32: Heat conductor 34: Uneven part 34a: Convex part 34b: recess 36: Flow path 38: Bearing 39: Containment space 40: Bulkhead C: Central axis of rotation D: Consumer G: Power supply L: Power system M : Hot Media

Claims

1. a stator configured by a cylindrical iron core along the direction of rotation and holding a winding; a rotor including a heating conductor disposed inside the stator; a flow path formed between the stator and the rotor, through which a heat medium flows; 10. A rotary heating machine, wherein the heating conductor is made of a lump of soft magnetic conductor.

2. 2. The rotary heating machine according to claim 1, wherein the outer peripheral surface of the heating conductor is formed with an uneven portion.

3. 3. The rotary heating machine according to claim 2, wherein the uneven portion is formed by alternately arranging recesses and protrusions in the circumferential direction.

4. the core includes a plurality of teeth arranged in a circumferential direction, 4. The rotary heating machine according to claim 1, wherein the teeth have a constant width in the circumferential direction.

5. the core includes a plurality of teeth formed side by side in a circumferential direction and slots formed between the teeth adjacent to each other in the circumferential direction, The tooth portion has a constant circumferential width, 4. The rotary heating machine according to claim 3, wherein the value obtained by dividing the number of recesses by the number of slots is 7 / 6 or more.

6. the core includes a plurality of teeth formed side by side in a circumferential direction and slots formed between the teeth adjacent to each other in the circumferential direction, 4. The rotary heating machine according to claim 1, wherein the slots have a constant width in the circumferential direction.

7. the core includes a plurality of teeth formed side by side in a circumferential direction and slots formed between the teeth adjacent to each other in the circumferential direction, each of the plurality of teeth includes a tip portion that forms a region that comes into contact with the heat transfer medium, and a base portion that extends substantially parallel to a radial direction and forms a region other than the tip portion; The tip portion is formed in a flange shape that protrudes from the base portion on both sides in the circumferential direction, 4. The rotary heating machine according to claim 3, wherein the number of the slots is the same as the number of the recesses.

8. the core includes a plurality of teeth arranged in a circumferential direction, The plurality of teeth have tip portions that form an area that comes into contact with the heat transfer medium; a base portion that forms an area other than the tip portion, The tip portion is made of a mass of soft magnetic conductor, 3. The rotary heating machine according to claim 1, wherein the base is made of a laminated steel plate or a soft magnetic nonmetal.

9. 4. An electrothermal converter comprising: the rotary heating machine according to claim 1; and an electric motor that rotates the rotor via a shaft.

10. The electrothermal converter according to claim 9 ; a heat storage device that stores the heat medium and supplies and recovers the heat medium to the rotary heating machine; a heat utilization device that utilizes the heat of the heat medium supplied from the heat storage device;

Images