JP2020042972A - Electromagnetic wave heating device and electromagnetic wave heating system - Google Patents

Abstract

To provide an electromagnetic wave heating device capable of improving utilization efficiency of energy.SOLUTION: An electromagnetic wave heating device 1 includes a cooler 20, a wave guide 30, and a heating apparatus 40. The cooler 20 has at least one radiation fin 21. The cooler 20 ejects heat, generated in an electromagnetic wave generator 10 outputting electromagnetic waves, by the radiation fin 21. The wave guide 30 has an opening 36 at a part, and propagates electromagnetic waves. The heating apparatus 40 is placed in the wave guide 30. The heating apparatus 40 has an electromagnetic wave absorber 41 heated by the electromagnetic waves. The heating apparatus 40 heats gas V passing through the internal space 31 of the wave guide 30. The radiation fin 21 is exposed from the opening 36 to the internal space 31 of the wave guide 30.SELECTED DRAWING: Figure 2

Description

  The present disclosure relates generally to an electromagnetic wave heating device and an electromagnetic wave heating system, and more particularly to an electromagnetic wave heating device and an electromagnetic wave heating system provided with an electromagnetic wave absorber.

  Patent Document 1 discloses a heating chamber outer body, a door provided on an outer wall for closing the heating chamber outer body, a heating element, a micro tube connected to the heating chamber by a waveguide, and connected to a cooling blower and an air duct leading to the front of the cooking device. A cooker having a wave oscillator is described.

JP-A-61-211984

  However, in the heating cooker (electromagnetic wave heating device) as disclosed in Patent Literature 1, some energy loss occurs, and therefore, improvement in energy use efficiency has been desired.

  The present disclosure has been made in view of the above circumstances, and it is an object of the present disclosure to provide an electromagnetic wave heating device and an electromagnetic wave heating system capable of improving energy use efficiency.

  An electromagnetic wave heating device according to an aspect of the present disclosure includes a cooling device, a waveguide, and a heating device. The cooling device has at least one heat radiation fin, and emits heat generated by an electromagnetic wave generator that outputs an electromagnetic wave through the heat radiation fin. The waveguide has an opening in a part and propagates the electromagnetic wave. The heating device includes an electromagnetic wave absorber that is disposed inside the waveguide and is heated by the electromagnetic wave, and heats a gas that passes through an internal space of the waveguide. The radiation fin is exposed to the internal space of the waveguide from the opening.

  An electromagnetic wave heating system according to an aspect of the present disclosure includes the electromagnetic wave heating device and the electromagnetic wave generator.

  According to the present disclosure, there is an advantage that energy use efficiency can be improved.

FIG. 1 is a perspective view illustrating the electromagnetic wave heating system according to the first embodiment. FIG. 2 is a cross-sectional view illustrating the electromagnetic heating system according to the first embodiment. FIG. 3A is a cross-sectional view showing a waveguide used in the electromagnetic wave heating system of the above. FIG. 3B is a cross-sectional view showing a waveguide having a reflection characteristic equivalent to that of the waveguide of FIG. 3A. FIG. 3C is a graph showing the reflection characteristics of the waveguides of FIGS. 3A and 3B. FIG. 4 is a sectional view showing a transmission line used in the electromagnetic wave heating system of the above. FIG. 5 is a perspective view showing the electromagnetic wave heating system according to the second embodiment. FIG. 6 is a sectional view showing a transmission line used in the electromagnetic wave heating system of the above. FIG. 7 is a cross-sectional view illustrating the electromagnetic wave heating system according to the third embodiment.

(Embodiment 1)
The electromagnetic wave heating device 1 according to the present embodiment and the electromagnetic wave heating system 101 including the same will be described with reference to FIGS. The electromagnetic wave heating device 1 forms an electromagnetic wave heating system 101 together with the electromagnetic wave generator 10. In other words, the electromagnetic wave heating system 101 includes the electromagnetic wave heating device 1 and the electromagnetic wave generator 10. The direction of arrow X in the figure is the forward direction, and the direction opposite to arrow X is the backward direction. The direction of arrow Y in the figure is rightward, and the direction opposite to arrow Y is leftward. The direction of the arrow Z in the figure is the upward direction, and the direction opposite to the arrow Z is the downward direction.

(1) Outline Heating using an electromagnetic wave such as a microwave is different from a heating wire heater or a far-infrared ray or gas heater that indirectly heats an object to be heated from the surface, and directly heats the inside of the object to be heated that absorbs the electromagnetic wave. can do. Therefore, compared to the case of indirect heating, the object to be heated can be heated quickly and efficiently.

  Therefore, realization of an instantaneous heating device using heating using electromagnetic waves is desired. That is, there is a demand for a heating device capable of obtaining heat in a short time (instantaneous) when operated when it is desired to take warmth. Such heating devices are particularly useful during cold months (such as during winter) and are eagerly awaited in cold climates. When the above-described heating device is used for a vehicle such as an automobile, for example, the inside of the vehicle can be heated in a shorter time than an air conditioner (car air conditioner) using exhaust heat of an engine. In addition, the above-described heating device can be used in a field where it is desired to obtain heat in a short time, for example, a health field or an industrial field.

  By the way, heating using electromagnetic waves requires an electromagnetic wave generator to generate electromagnetic waves. The electromagnetic wave generator converts power from a power supply such as a DC (Direct Current) power supply into electromagnetic waves, but cannot convert it with 100% efficiency. That is, the electric power that is not converted into an electromagnetic wave changes into heat or the like. Then, it is desirable to radiate the heat so that the heat is not stored in the electromagnetic wave generator in order to reduce the performance deterioration or thermal damage of the electromagnetic wave generator.

  The electromagnetic wave heating system 101 according to the present embodiment intends to improve energy use efficiency by radiating heat generated by conversion loss or the like in the electromagnetic wave generator and using the radiated heat for heating.

  That is, the electromagnetic wave heating device 1 according to the present embodiment includes the cooling device 20, the waveguide 30, and the heating device 40. The cooling device 20 has at least one radiation fin 21. The cooling device 20 emits heat generated by the electromagnetic wave generator 10 that outputs an electromagnetic wave through the radiation fins 21. The waveguide 30 has an opening 36 in a part. The waveguide 30 propagates an electromagnetic wave. The heating device 40 has an electromagnetic wave absorber 41 disposed inside the waveguide 30. The electromagnetic wave absorber 41 is heated by the electromagnetic wave. The heating device 40 heats the gas V passing through the internal space 31 of the waveguide 30. The radiation fins 21 are exposed from the opening 36 to the internal space 31 of the waveguide 30.

  According to the present embodiment, the electromagnetic wave absorber 41 is instantaneously heated by the electromagnetic wave, and when the gas V comes into contact with the electromagnetic wave absorber 41, the gas V is heated to generate warm air in a short time. It can be used for heating, etc. Furthermore, the gas V can be heated by the heat radiation fins 21 by the heat radiation fins 21 exposed to the internal space 31 of the waveguide 30 being in contact with the gas V. That is, the heat generated by the electromagnetic wave generator 10 can also be used for heating the gas V. Therefore, in the present embodiment, it is possible to obtain heat such as hot air in a relatively short time and with relatively high energy efficiency. “Warm air” as referred to in the present disclosure means a gas whose temperature is higher than normal temperature, that is, a warm gas (air).

(2) Details Hereinafter, the electromagnetic wave heating device 1 and the electromagnetic wave heating system 101 according to the present embodiment will be described in more detail. The electromagnetic wave heating system 101 includes the electromagnetic wave generator 10 and the electromagnetic wave heating device 1 as described above. The electromagnetic wave heating device 1 includes a cooling device 20, a waveguide 30, and a heating device 40. That is, in the present embodiment, the electromagnetic wave generator 10 is not included in the components of the electromagnetic wave heating device 1.

(2.1) Electromagnetic Wave Generator In this embodiment, a case where the electromagnetic wave generator 10 generates a microwave will be described as an example. That is, the electromagnetic wave generator 10 includes a microwave power supply, and outputs a microwave that is a radio wave (electromagnetic wave) having a frequency of 300 MHz or more and 3 THz or less. In particular, the microwave power supply uses an amplifier circuit including a solid-state element (semiconductor element). In a microwave power supply using such a solid-state element, the oscillation frequency can be stabilized and the size can be reduced as compared with a microwave power supply using a magnetron.

  As shown in FIGS. 1 and 2, the electromagnetic wave generator 10 further includes a case 11, a transmission line 50, and an antenna 70 in addition to the microwave power supply.

  The case 11 houses an electric circuit such as a microwave power supply. Case 11 is formed of a material having thermal conductivity. The case 11 is preferably made of metal in order to enhance thermal conductivity, and is made of metal such as copper, iron or aluminum. The lower surface of the case 11 is a flat surface. In this case, as compared with the case where the lower surface of case 11 is an uneven surface, the contact area with cooling device 20 is increased, and the heat transfer from electromagnetic wave generator 10 to cooling device 20 is less likely to be impaired.

  The transmission line 50 transmits an electric signal generated by a microwave power supply. In the present embodiment, the transmission line 50 is constituted by the inner conductor 55 of the coaxial cable 53. That is, the electromagnetic wave generator 10 has the coaxial cable 53, and a part (the inner conductor 55) of the coaxial cable 53 functions as the transmission line 50. The coaxial cable 53 has an inner conductor 55, an outer conductor 51, and an insulator 52. That is, in the coaxial cable 53, the outer conductor 51 is coaxially arranged outside the inner conductor 55 which is a core wire. An insulator 52 is provided between the inner conductor 55 and the outer conductor 51. The insulator 52 electrically insulates the inner conductor 55 from the outer conductor 51. The coaxial cable 53 protrudes out of the case 11 (downward). Then, the internal conductor 55 transmits an electric signal generated by the microwave power supply to the antenna 70 as the transmission line 50. The inner conductor 55 is electrically connected to a microwave power supply in the case 11. The tip of the internal conductor 55 projects outside the case 11. Thus, the inner conductor 55 transmits an electric signal generated by the microwave power supply to the outside of the case 11. By using the coaxial cable 53, leakage of an electric signal from the transmission line 50 to the outside and superposition of electromagnetic waves from the outside to the transmission line 50 are less likely to occur, and a shielding effect is obtained. The antenna 70 is connected to the tip of the internal conductor 55. Thus, the antenna 70 and the microwave power supply are electrically connected via the internal conductor 55 (the transmission line 50). The antenna 70 is formed, for example, in a columnar shape. The antenna 70 is formed of a conductor, for example, copper, iron, or aluminum. An electric signal is input to the antenna 70 from a microwave power supply through the internal conductor 55, and the antenna 70 radiates an electromagnetic wave (microwave) into the air.

(2.2) Cooling device The cooling device 20 cools the electromagnetic wave generator 10. In the present embodiment, the cooling device 20 is an air-cooled type. In the present embodiment, the cooling device 20 includes a base portion 22 and a plurality of radiating fins 21. The cooling device 20 further includes a cooling wall 25 described below.

  In the present embodiment, the cooling device 20 includes a plurality of radiating fins 21, but the cooling device 20 may include at least one radiating fin 21. It is preferable that the number and intervals of the radiation fins 21 are set according to the frequency (wavelength) of the electromagnetic wave to be used. The base portion 22 and the plurality of radiating fins 21 are realized by, for example, a heat sink. The cooling device 20 is formed of a material having thermal conductivity. The cooling device 20 is preferably made of a metal in order to increase thermal conductivity, and is made of a metal such as copper, iron or aluminum.

  Each radiation fin 21 protrudes downward from the lower surface of the base portion 22. Each of the heat radiation fins 21 is arranged in a direction in which the thickness direction coincides with the left-right direction. The plurality of radiation fins 21 are arranged in the thickness direction. That is, the plurality of radiating fins 21 are arranged in the left-right direction at intervals. One surface 211 in the thickness direction of the adjacent heat radiation fins 21 faces each other. That is, the right surface (or left surface) of the heat radiation fin 21 faces the left surface (or right surface) of another adjacent heat radiation fin 21. Therefore, each radiation fin 21 is long in the front-back direction.

  The interval P between the adjacent heat radiation fins 21 is 1/16 or less of the wavelength of the electromagnetic wave used. That is, when the wavelength of the electromagnetic wave output from the electromagnetic wave generator 10 is λ, P is λ / 16 or less (P ≦ λ / 16). For example, when using a 2.4 GHz microwave, the interval P can be 7.6 mm or less. The lower limit of the interval P is not particularly set. From the viewpoint of forming (assuming) a virtual plane S for shielding electromagnetic waves, which will be described later, at a part of the inner surface of the waveguide 30 at the tips 213 of the radiation fins 21, the interval P is small. No problem. However, in the present embodiment, since the gas V is radiated between the adjacent radiating fins 21, heat is radiated from the viewpoint of the flow of the gas V and the number of the radiating fins 21 so that effective heat radiation conditions can be obtained. The lower limit of the interval P is set.

(2.3) Waveguide The waveguide 30 is, for example, a rectangular waveguide having a rectangular cross section. The waveguide 30 is a hollow tube having an internal space (cavity) 31. The waveguide 30 is formed of a conductive material, for example, a metal such as copper, iron, or aluminum.

  The waveguide 30 is a cylindrical body whose axial direction is long in the front-back direction. The waveguide 30 has a bottom surface 353, an upper surface 352, and a pair of side surfaces 351. The waveguide 30 has an intake port 32 at the rear end. The waveguide 30 has an exhaust port 34 at the front end. The intake port 32 and the exhaust port 34 face each other. The internal space 31 is connected to an intake port 32 and an exhaust port 34. Further, the waveguide 30 has an opening 36.

  The opening 36 is provided at a position near the rear end of the upper surface 352. The opening 36 is a through hole that penetrates a part of the upper surface 352 in the thickness direction (vertical direction). Therefore, even through the opening 36, the internal space 31 of the waveguide 30 and the space outside the waveguide 30 are connected. The cooling wall 25 is provided above the upper surface 352. The cooling wall 25 surrounds the opening 36 outside the waveguide 30. The cooling wall 25 is formed integrally with the upper surface 352. The cooling wall 25 has a front part 355, a rear part 356, and a pair of upper side parts 354. The front part 355 is located in front of the opening 36. The rear surface 356 is located behind the opening 36. The pair of upper side surfaces 354 are respectively located on the sides of the opening 36.

(2.4) Heating device The heating device 40 absorbs the electromagnetic waves generated by the electromagnetic wave generator 10 and generates heat. In other words, the heating device 40 is heated by the electromagnetic waves generated by the electromagnetic wave generator 10. The heating device 40 includes an electromagnetic wave absorber 41. The electromagnetic wave absorber 41 absorbs electromagnetic waves and generates heat.

  The electromagnetic wave absorber 41 converts the energy of the incident electromagnetic wave into heat energy inside. In other words, the electromagnetic wave absorber 41 generates heat by being heated by the vibration of the molecules by the electromagnetic wave. In the present embodiment, the electromagnetic wave absorber 41 includes silicon carbide (SiC). The electromagnetic wave absorber 41 containing silicon carbide has a large dielectric loss in a microwave region at room temperature, and easily generates heat. The shape of the electromagnetic wave absorber 41 is not particularly limited, and is a rectangular plate in the present embodiment, but may be a disk, an ellipse, a polygon, or the like.

(2.5) Electromagnetic Wave Heating Device The electromagnetic wave heating device 1 according to the present embodiment includes a cooling device 20, a waveguide 30, and a heating device 40. The cooling device 20 is attached to the waveguide 30. The cooling device 20 is attached to the waveguide 30 such that the distal end 213 of the radiation fin 21 is exposed from the opening 36 to the internal space 31. That is, the distal end (lower end) 213 of the radiation fin 21 faces the internal space 31 from the opening 36. In the present embodiment, the cooling device 20 is attached to the waveguide 30 such that the tip 213 of the radiation fin 21 is positioned at the same height as the opening 36. That is, the virtual plane S including the tips 213 of the plurality of radiation fins 21 is located in the opening 36. That is, the tip 213 of the radiation fin 21 is located between both surfaces (upper surface and lower surface) in the thickness direction of the upper surface 352 so as to be located in the opening 36 penetrating the upper surface 352 in the thickness direction. Here, it is preferable that the lower surface of the upper surface portion 352, that is, the inner side surface (the surface on the side of the internal space 31) of the waveguide 3, and the virtual plane S are substantially flush.

  The peripheral end of the lower surface of the base 22 of the cooling device 20 is placed on the upper end of the front part 355, the upper end of the rear part 356, and the upper end of the pair of upper side parts 354. Further, the cooling device 20 and the waveguide 30 are electrically connected.

  Further, the cooling device 20 is arranged so that the length direction of each heat radiation fin 21 extends in the front-back direction. That is, the plurality of radiating fins 21 are arranged in the left-right direction, but each radiating fin 21 has a length in the front-rear direction orthogonal to the left-right direction. The front end surface 212 of each heat radiation fin 21 is in contact with the front peripheral edge 361 of the opening 36. The rear end surface 214 of each radiating fin 21 is in contact with the rear peripheral edge 362 of the opening 36. Thereby, each radiation fin 21 and the waveguide 30 are electrically connected. Since the opening 36 is a through hole, the peripheral edges 361 and 362 are formed by the inner peripheral surface of the through hole. Therefore, the vertical dimension of the peripheral edges 361 and 362 is the same as the thickness of the upper surface 352.

  The radiation fins 21 form a flow path 215. Here, the space between the adjacent heat radiation fins 21 is used as the flow path 215. That is, the radiation fin 21 forms the flow path 215 that allows the gas V flowing out of the waveguide 3 from the opening 36 to pass along one surface in the thickness direction of the radiation fin 21. The plurality of radiation fins 21 form a plurality of flow paths 215. Each flow path 215 is open at the lower surface, and each flow path 215 is connected to the internal space 31 through the opening 36. A front surface 355 is located in front of each flow channel 215, and a rear surface 356 is located behind each flow channel 215.

  Heating device 40 is arranged in internal space 31. The heating device 40 is arranged between the inlet 32 and the outlet 34. Further, the heating device 40 is disposed downstream with respect to the channel 215. That is, the flow path 215 is disposed on the upstream side (rear side) of the heating device 40 when viewed in the entire path through which the gas V flows. In other words, the heating device 40 is arranged on the downstream side (front side) of the opening 36. That is, the heating device 40 is disposed between the opening 36 and the exhaust port 34 on the path through which the gas V flows.

(2.6) Electromagnetic Wave Heating System The electromagnetic wave heating system 101 according to the present embodiment includes an electromagnetic wave heating device 1 and an electromagnetic wave generator 10. The electromagnetic wave generator 10 has a case 11 mounted on a cooling device 20. That is, the lower surface of the case 11 is in contact with the upper surface of the base portion 22. Thereby, the case 11, the cooling device 20, and the waveguide 30 are electrically connected. Further, the case 11 and each of the radiation fins 21 are thermally and mechanically connected via the base portion 22.

  The coaxial cable 53 of the electromagnetic wave generator 10 is inserted into the cooling device 20. In this case, a through hole is provided at the center of the base portion 22 in plan view, and the coaxial cable 53 is inserted into the through hole. The through-hole is formed by cutting off a part of the base part 22 and a part of the radiation fin 21. The outer conductor 51 is in contact with and electrically connected to the base portion 22 and the radiation fins 21. The internal conductor 55 extends further below the flow path 215. That is, the internal conductor 55 extends from the flow path 215 to the internal space 31 through the opening 36. The antenna 70 of the electromagnetic wave generator 10 is connected to the tip of the internal conductor 55 and located in the internal space 31. The inner conductor 55 becomes a hot line, and the outer conductor 51 is electrically connected to the ground to become a cold line. The cooling device 20 and the waveguide 30 electrically connected to the external conductor 51 are also electrically connected to the ground. “Ground” in the present disclosure is a reference potential point in the microwave power supply of the electromagnetic wave generator 10.

(2.7) Operation The electromagnetic wave heating system 101 according to the present embodiment operates as follows.

  First, an electromagnetic wave is generated by the electromagnetic wave generator 10. An electric signal generated by a microwave power supply or the like of the electromagnetic wave generator 10 is supplied to the antenna 70 through the transmission line 50. The electric signal supplied to the antenna 70 is radiated from the antenna 70 to the internal space 31 as an electromagnetic wave. The electromagnetic wave radiated from the antenna 70 travels through the internal space 31 and is applied to the electromagnetic wave absorber 41. This electromagnetic wave is absorbed by the electromagnetic wave absorber 41, and the electromagnetic wave absorber 41 generates heat. In the present embodiment, for example, a frequency band of 2.4 GHz is used as the frequency band of the electromagnetic wave.

  Here, the electromagnetic wave traveling in the internal space 31 is a transverse electric field wave (TE wave) in which no magnetic field exists in the forward direction. That is, only the magnetic field has a component in the tube axis direction (front-back direction) of the waveguide 30, and the electric field is an electromagnetic wave having a component in the direction perpendicular to the tube axis direction. In addition, this electromagnetic wave has one peak of the change in which the electric field is distributed by a change of 波長 wavelength in the left-right direction, but has no change in the vertical direction and has no peak. Thus, the electromagnetic field distribution in the waveguide 30 becomes the TE-10 mode.

  In the present embodiment, the traveling direction of the electromagnetic wave and the length direction of each radiating fin 21 are substantially parallel. For this reason, as shown in FIG. 3A, a virtual plane S formed by the tips 213 of the plurality of radiation fins 21 exists in the opening 36 of the waveguide 30. The virtual plane S is a virtual plane to which the tips 213 of the radiation fins 21 belong. This virtual plane S acts as a shield surface through which electromagnetic waves do not pass. Therefore, despite the fact that the waveguide 30 has the opening 36, it has the same performance as the waveguide without the opening 36. That is, as shown in FIG. 3B, a waveguide 30a in which an inner space 31a surrounded by a bottom surface portion 353a, an upper surface portion 352a, and a pair of side surface portions 351a is a waveguide, and a waveguide of this embodiment. 30 has the same performance.

  FIG. 3C shows a simulation of the reflection characteristics of the waveguide 30 and the waveguide 30a of the present embodiment. In the present embodiment, for example, an electromagnetic wave having a frequency of not less than 2.4 GHz and not more than 2.5 GHz is used, and the reflection characteristics of the waveguide 30 and the waveguide 30a at this frequency can be considered to be equivalent. That is, the cross-sectional area of the internal space 31 of the waveguide 30 and the cross-sectional area of the internal space 31a of the waveguide 30a are substantially the same, and the cross-sectional shapes of both are substantially the same. Therefore, the impedance between the waveguide 30 and the waveguide 30a hardly changes, and the voltage standing wave ratio (VSWR) becomes substantially the same. For this reason, the waveguide 30 and the waveguide 30a can be regarded as equivalent with respect to the waveguide characteristics of electromagnetic waves.

  In order to configure (assume) such a virtual plane S, the length direction of each heat radiation fin 21 is oriented in the front-back direction. That is, each radiating fin 21 has a length along the traveling direction of the electromagnetic wave in the waveguide 30. For example, if the length direction of the radiation fins 21 is the left-right direction, it becomes difficult for high-frequency current to flow, and electromagnetic waves are lost.

  On the other hand, the gas V is supplied to the waveguide 30. In the present embodiment, the gas V is air, but may be another gas such as nitrogen. When the gas V is air, the gas V is blown from the intake port 32 of the waveguide 30 using a blower or the like. Part of the gas V supplied into the waveguide 30 from the intake port 32 flows out of the internal space 31 through the opening 36 and passes through the flow path 215 as the first gas V1. Another part of the gas V supplied into the waveguide 30 from the inlet 32 passes through the internal space 31 as the second gas V2.

  The first gas V <b> 1 contacts one surface 211 of each heat radiation fin 21 when passing through the flow path 215. Thereby, heat is transmitted from each radiation fin 21 to the first gas V1, and the first gas V1 is heated. Further, each heat radiation fin 21 is cooled by the heat taken by the first gas V1. Thereby, the heat generated by the electromagnetic wave generator 10 is transmitted to the first gas V1, and the electromagnetic wave generator 10 is cooled.

  The heated first gas V1 flows into the internal space 31 from the flow path 215 through the opening 36. Thus, the heated first gas V1 and the unheated second gas V2 are mixed. Therefore, the second gas V2 can be heated by the heated first gas V1. Thereafter, the first gas V1 and the second gas V2 flow into the electromagnetic wave absorber 41 in a mixed state. That is, before contacting the electromagnetic wave absorber 41, the gas V (the first gas V1 and the second gas V2) is heated. Then, the gas V (the first gas V <b> 1 and the second gas V <b> 2) contacts the heating electromagnetic wave absorber 41, and heat is transferred from the electromagnetic wave absorber 41 to the gas V. Thus, the gas V passing through the internal space 31 is heated. Thereafter, the heated gas V becomes, for example, hot air and is exhausted from the exhaust port 34 to the outside of the waveguide 30.

  In this manner, in the present embodiment, the electromagnetic wave absorber 41 is heated by the electromagnetic wave, and the heated electromagnetic wave absorber 41 can heat a gas such as air. Therefore, warm air or the like can be obtained in a short time, and can be suitably used for instant heating. In addition, heat generated by the electromagnetic wave generator 10 can be used, and the energy use efficiency can be improved.

(3) Modification Example Embodiment 1 is only one of various embodiments of the present disclosure. Various changes can be made to the first embodiment according to the design and the like as long as the object of the present disclosure can be achieved.

  In the above, the case where the case 11 of the electromagnetic wave generator 10 and the cooling device 20 are in contact with each other and the heat generated in the electromagnetic wave generator 10 is directly conducted from the case 11 to the cooling device 20 has been described. I can't. For example, the cooling device 20 may be a radiator. In this case, heat conduction from the electromagnetic wave generator 10 to the cooling device 20 is performed via a fluid such as water.

  In the above description, both the first gas V1 and the second gas V2 are separated from the gas V sucked into the internal space 31 from the suction port 32, but are not limited thereto. For example, the first gas V1 and the second gas V2 may be separately suctioned. The heated first gas V1 and the heated second gas V2 are exhausted from the exhaust port 34 in a mixed state, but are not limited thereto. For example, the heated first gas V1 and the heated second gas V2 may be separately exhausted. Also in this case, the heated first gas V1 and the heated second gas V2 can be combined outside the electromagnetic wave heating device 1 to obtain a heated gas. Alternatively, even when the first gas V1 and the second gas V2 do not merge, for example, heat exchange is performed between the heated first gas V1 and the second gas V2, and the first gas V1 Can be transferred to the second gas V2 and used for heating the second gas V2.

  In the above description, the case where a rectangular waveguide is used as the waveguide 30 has been described. However, the shape of the cross section is not limited to the waveguide 30 having a linear shape. Waveguide 30 may be used. Further, the waveguide 30 may have an asymmetric cross-sectional shape (asymmetry).

  In the above description, the heating device 40 is disposed downstream with respect to the flow channel 215, but is not limited thereto. The heating device 40 may be arranged upstream with respect to the flow channel 215. That is, the channel 215 may be located downstream of the heating device 40.

  In the above description, the tip 213 of each heat radiation fin 21 is located at the same height as the opening 36, but is not limited to this. For example, the tip 213 of each heat radiation fin 21 may be located above the opening 36, that is, outside the waveguide 30. In this case, the tip 213 of each radiating fin 21 is located in the space inside the cooling wall 25. Alternatively, the tip 213 of each radiation fin 21 may be located below the opening 36, that is, inside the waveguide 30. In this case, the tip 213 of each radiation fin 21 is located in the internal space 31.

(Embodiment 2)
The electromagnetic wave heating device 2 and the electromagnetic wave heating system 102 of the present embodiment will be described with reference to FIGS.

  The configuration of the transmission line 60 of the electromagnetic wave heating device 2 according to the present embodiment is different from that of the electromagnetic wave heating device 1 according to the first embodiment.

  The electromagnetic wave heating system 102 of the present embodiment includes the electromagnetic wave generator 10 and the electromagnetic wave heating device 2.

  Hereinafter, the same components as those of the first embodiment are denoted by the same reference numerals, and the description thereof will be appropriately omitted.

  The configuration described in the second embodiment can be applied in appropriate combination with the configuration (including the modification) described in the first embodiment.

  In the present embodiment, the transmission line 60 is a strip line having the radiation fins 29 as conductors of the reference potential. Specifically, the transmission line 60 is a plate-shaped conductor, protrudes from the lower surface of the case 11 of the electromagnetic wave generator 10, and is inserted into the channel 215 through the through hole 24 in the base portion 22 as shown in FIG. ing. The transmission line 60 reaches the internal space 31 through a space between a pair of adjacent radiation fins 29 located at the center in the left-right direction. An antenna 70 is electrically connected to the end of the transmission line 60.

  Since such a transmission line 60 is located between the pair of radiating fins 29 as conductors, it is arranged along a conductor (radiating fin 29) electrically connected to the reference potential. . Therefore, the transmission line 60 constitutes a microstrip line.

  As described above, in the present embodiment, the transmission line 60 can be a microstrip line using the radiation fins 21, and the supply of electromagnetic waves from the electromagnetic wave generator 10 to the antenna 70 can be performed stably.

(Embodiment 3)
The electromagnetic wave heating device 3 and the electromagnetic wave heating system 103 of the present embodiment will be described with reference to FIG.

  The electromagnetic wave heating device 3 according to the present embodiment includes a guide member 80 in addition to the electromagnetic wave heating device 1 or 2 (including modified examples) according to the first or second embodiment.

  The electromagnetic wave heating system 103 of the present embodiment includes the electromagnetic wave generator 10 and the electromagnetic wave heating device 3.

  Hereinafter, the same components as those of the first or second embodiment are denoted by the same reference numerals, and the description thereof will not be repeated.

  In the present embodiment, the front end surface 212 in the length direction of each heat radiation fin 21 is prevented from contacting the front peripheral edge 361 of the opening 36 and the inner surface 357 of the front surface 355. Also, the rear end surface 214 in the length direction of the heat radiation fin 21 is prevented from contacting the rear peripheral edge 362 of the opening 36 and the inner surface 357 of the rear surface portion 356. That is, the front end surface 212 of each heat radiation fin 21 has the gap 33 between the front peripheral edge 361 of the opening 36 and the inner surface 357 of the front portion 355. The rear end surface 214 of each heat radiation fin 21 also has a gap 33 between the rear peripheral edge 362 of the opening 36 and the inner surface 358 of the rear surface 356. It is preferable that the dimension t of the gap 33 in the front-rear direction is equal to or less than の of the wavelength of the electromagnetic wave. For example, when using a 2.4 GHz microwave, the interval P can be set to 15.2 mm or less. Thus, the electromagnetic wave characteristics of the waveguide 30 can be made substantially the same as those in the first and second embodiments. Note that the case where t is 0 is the case of the first and second embodiments, and the end surface 212 is in contact with the peripheral edge 361 and the inner surface 357, and the end surface 214 is in contact with the peripheral edge 362 and the inner surface 358.

  When the cooling device 20 is attached to the waveguide 30 as described above, when the cooling device 20 is attached to the waveguide 30, the longitudinal ends of the radiation fins 21 do not easily contact the peripheral edges 361 and 362, the front surface 355, and the rear surface 356. This makes it easier to attach the cooling device 20 to the waveguide 30. On the other hand, in the case of the first and second embodiments, since the end surface 212 and the inner surface 357 are in contact, the electrical connection between the cooling device 20 and the waveguide 30 can be improved.

  Further, in the present embodiment, the electromagnetic wave heating device 3 includes the guide member 80. The guide member 80 protrudes from the bottom surface 353 near the intake port 32 toward the opening 36, that is, upward. Further, the guide member 80 is inclined with respect to the bottom surface 353 so that the distance from the bottom surface 353 increases as the distance from the intake port 32 increases. This facilitates the flow of the gas V flowing from the intake port 32 toward the opening 36 by the guide member 80, that is, toward the flow path 215. Therefore, the amount of the first gas V1 that comes into contact with the radiation fins 21 can be increased. Therefore, more heat can be transmitted from the radiation fins 21 to the first gas V1, and the cooling effect of the radiation fins 21 can be improved. Further, the first gas V1 can increase the heat obtained from the radiation fins 21 and can further improve the energy use efficiency.

  In the present embodiment, another guide member 81 is provided in the channel 215. The guide member 81 protrudes from the base 22 toward the opening 36, that is, downward. Furthermore, the guide member 81 is inclined with respect to the base portion 22 so that the distance from the base portion 22 increases as the distance from the intake port 32 increases. Thereby, the first gas V <b> 1 that has flowed into the flow channel 215 easily flows toward the opening 36 by the guide member 81, that is, toward the internal space 31. Therefore, the first gas V1 heated in the flow path 215 and the second gas V2 flowing in the internal space 31 are easily merged, and the second gas V2 is efficiently heated. Can be. Further, all of the gas V that has flowed into the internal space 31 from the intake port 32 flows into the flow path 215 as the first gas V1, and after the first gas V1 is heated by the radiating fins 21, the first gas V1 is opened. You may make it flow into the internal space 31 from the part 36. In this case, after heating all of the gas V flowing into the internal space 31 from the intake port 32, the gas V can be heated by the heating device 40, and the heating efficiency of the gas V by the heating device 40 can be improved.

(Summary)
As described above, the electromagnetic wave heating device (1, 2, 3) according to the first aspect includes the cooling device (20), the waveguide (30), and the heating device (40). The cooling device (20) has at least one radiating fin (21), and radiates heat generated by the electromagnetic wave generator (10) that outputs an electromagnetic wave through the radiating fin (21). The waveguide (30) partially has an opening (36) and propagates electromagnetic waves. The heating device (40) is disposed inside the waveguide (30), has an electromagnetic wave absorber (41) heated by an electromagnetic wave, and has a gas (31) that passes through the internal space (31) of the waveguide (30). V) is heated. The radiation fin (21) is exposed from the opening (36) to the internal space (31) of the waveguide (30).

  According to this aspect, the gas passing through the internal space (31) of the waveguide (30) is heated by the heat radiated from the radiation fins (21) through the openings (36). Therefore, in addition to the heating of the gas (V) by the electromagnetic wave absorber (41), the gas (V) can be heated by utilizing the heat of the electromagnetic wave generator (10), thereby improving energy efficiency. There is an advantage that can be. In addition, since at least a part of the opening (36) provided in the waveguide (30) is closed by the radiation fin (21), the electromagnetic wave is less likely to leak from the internal space (31) through the opening (36). Become. Therefore, there is an advantage that the original function of the waveguide (30) for propagating electromagnetic waves is not easily impaired.

  An electromagnetic wave heating device (1, 2, 3) according to a second aspect is the first aspect, wherein there are a plurality of radiation fins (21). An imaginary plane (S) including the tips of the plurality of radiation fins (21) is located in the opening (36).

  According to this aspect, the opening (36) is closed by the virtual plane (S), the electromagnetic wave is less likely to leak from the internal space (31) through the opening (36), and the electromagnetic wave in the waveguide (30) is blocked. There is an advantage that the function of propagating is not easily impaired.

  In the electromagnetic wave heating device (1, 2, 3) according to a third aspect, in the first or second aspect, the radiation fin (21) is plate-shaped. The radiating fins (21) flow the gas (V) flowing out of the waveguide (30) through the openings (36) along one surface (211) in the thickness direction of the radiating fins (21). A path (215) is formed.

  According to this aspect, when the gas (V) flowing out of the waveguide (30) from the opening (36) passes through the flow path (215), one surface (in the thickness direction) of the heat radiation fin (21) is formed. 211), and the gas (V) can be easily heated.

  In the electromagnetic wave heating device (1, 2, 3) according to the fourth aspect, in the third aspect, the heating device (40) is arranged upstream or downstream with respect to the flow path (215).

  According to this aspect, when the heating device (40) is arranged downstream with respect to the flow path (215), the gas (V) heated by the radiation fins (21) and the heating device (40). And the heated gas (V). Therefore, there is an advantage that a large amount of heated gas (V) can be easily obtained. When the heating device (40) is disposed upstream of the flow path (215), the gas (V) heated by the radiation fins (21) is further heated by the heating device (40). Therefore, there is an advantage that the temperature of the gas (V) in the heating device (40) is easily increased.

  An electromagnetic wave heating device (3) according to a fifth aspect is the electromagnetic wave heating device (3) according to the third or fourth aspect, in which at least a part of the gas (V) passing through the internal space (31) of the waveguide (30) flows through the channel (215). And a guide member (80) that guides the guide member.

  According to this aspect, there is an advantage that the gas (V) easily flows through the flow path (215), and the utilization of heat from the radiation fins (21) is easily enhanced.

  An electromagnetic wave heating device (1, 2, 3) according to a sixth aspect is characterized in that, in any one of the first to fifth aspects, the number of the radiation fins (21) is plural. The electromagnetic wave generator (10) is disposed in a transmission line (50, 60) disposed between a plurality of radiation fins (21) and an internal space (31) of the waveguide (30). (50, 60) electrically connected to the antenna (70).

  According to this aspect, there is an advantage that electric energy can be stably supplied to the antenna (70) through the transmission line (50, 60).

  An electromagnetic wave heating device (1) according to a seventh aspect is the electromagnetic wave heating device (1) according to the sixth aspect, wherein the transmission line (50) is configured such that an inner conductor (55) of a coaxial cable (53) having an inner conductor (55) and an outer conductor (51). ).

  According to this aspect, there is an advantage that electric energy can be stably supplied to the antenna (70) through the transmission line (50) of the coaxial cable (53).

  An electromagnetic wave heating device (2) according to an eighth aspect is the electromagnetic wave heating device according to the sixth aspect, wherein the transmission line (60) is a strip line having the radiation fin (21) as a conductor of a reference potential.

  According to this aspect, there is an advantage that electric energy can be stably supplied to the antenna (70) through the strip line transmission line (60).

  An electromagnetic wave heating device (3) according to a ninth aspect is the electromagnetic wave heating device (3) according to any one of the first to eighth aspects, wherein the electromagnetic wave heating device is provided between the radiation fin (21) and the periphery (361, 362) of the opening (36). Has a gap (33) having a dimension (t) of one-eighth or less of the wavelength.

  According to this aspect, the radiation fin (21) hardly comes into contact with the peripheral edges (361, 362) of the opening (36), and the cooling device (20) including the radiation fin (21) in the waveguide (30). Has the advantage that it can be easily attached. In addition, there is an advantage that the electromagnetic wave is less likely to leak from the internal space (31) through the opening (36), and the original function of the waveguide (30) for transmitting the electromagnetic wave is not easily impaired.

  An electromagnetic wave heating system (101, 102, 103) according to a tenth aspect includes an electromagnetic wave heating device (1, 2, 3) and an electromagnetic wave generator (10).

  According to this aspect, in addition to the heating of the gas (V) by the electromagnetic wave absorber (41), the gas (V) can be heated by utilizing the heat of the electromagnetic wave generator (10), and energy efficiency can be improved. There is an advantage that improvement can be achieved.

1, 2, 3 electromagnetic wave heating device 10 electromagnetic wave generator 20 cooling device 21 radiating fin 215 flow path 30 waveguide 33 gap 36 opening 361, 362 peripheral edge 40 heating device 41 electromagnetic wave absorber 50 transmission line 51 outer conductor 53 coaxial cable 55 Internal conductor 60 Transmission line 70 Antenna 80 Guide member 101, 102, 103 Electromagnetic wave heating system V Gas

Claims (10)

A cooling device that has at least one heat radiation fin and emits heat generated by an electromagnetic wave generator that outputs an electromagnetic wave at the heat radiation fin,
A waveguide that has an opening in part and propagates the electromagnetic wave;
A heating device disposed inside the waveguide, having an electromagnetic wave absorber heated by the electromagnetic wave, and heating a gas passing through the internal space of the waveguide,
The radiation fin is exposed from the opening to the internal space of the waveguide,
Electromagnetic wave heating device. There are a plurality of the radiation fins,
A virtual plane including the tips of the plurality of radiation fins is located in the opening.
The electromagnetic wave heating device according to claim 1. The radiation fins are plate-shaped,
The radiating fins form a flow path that allows the gas flowing out of the waveguide from the opening to pass along one surface in the thickness direction of the radiating fins,
The electromagnetic wave heating device according to claim 1. The heating device is disposed upstream or downstream with respect to the flow path,
The electromagnetic wave heating device according to claim 3. Further comprising a guide member for guiding at least a part of the gas passing through the internal space of the waveguide to the flow path,
The electromagnetic wave heating device according to claim 3. There are a plurality of the radiation fins,
The electromagnetic wave generator,
A transmission line disposed between the plurality of radiation fins,
An antenna disposed in the internal space of the waveguide and electrically connected to the transmission line.
The electromagnetic wave heating device according to claim 1. The transmission line is the inner conductor of a coaxial cable having an inner conductor and an outer conductor,
The electromagnetic wave heating device according to claim 6. The transmission line is a strip line using the heat radiation fin as a conductor of a reference potential,
The electromagnetic wave heating device according to claim 7. A gap having a dimension of 1/8 or less of the wavelength of the electromagnetic wave is provided between the radiation fin and the periphery of the opening,
The electromagnetic wave heating device according to claim 1. An electromagnetic wave heating device according to any one of claims 1 to 9,
And the electromagnetic wave generator;
Electromagnetic heating system.

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