HEAT TRANSFER DEVICE AND OVEN EQUIPPED WITH IT

Abstract

Heat transfer device (10, 50), comprising: a housing extending over a high-temperature heat source (28) and a low-temperature heat bath (30) which has a lower temperature than the high-temperature heat source (28); comprising a closed space in which non-condensing gas is enclosed, wherein a conduit (X) is formed in the housing and both end sections of the conduit (X) are sealed; a regenerator (18) which is arranged in the conduit (X) and provided with pores (34) which connect the two end sections of the regenerator (18) together and which is insulated from the outside of the casing; a first heat exchanger (14) which is arranged next to the end section of the regenerator (18) on the high-temperature heat source side in the conduit (X) and which allows the heat from the high-temperature heat source (28) to be directed towards the regenerator (18); and a second heat exchanger (16) which is arranged next to the end section of the regenerator (18) on the low-temperature heat bath side in the line (X) and which allows the heat from the regenerator (18) to be directed towards the low-temperature heat bath (30), wherein the center of the regenerator (18) is arranged along the extension direction of the line (X) at a position in the line (X) which is between 12.5% ​​and 25% of the line length from the end section of the line (X) on the high-temperature heat source side.

Description

Technical field

[0001] The present disclosure relates to a heat transfer device and an oven equipped therewith. State of the art

[0002] Conventionally, various heat transfer devices are used. Types of heat transfer devices include (A) phase-change heat transfer devices and (B) heat transfer devices that utilize convective heat transfer (forced cooling) resulting from the forced flow of a heat transfer fluid.

[0003] Representative examples of type (A) heat transfer devices include heat pipes. A heat pipe is a device containing a working fluid that absorbs heat from a heat source by changing from a liquid to a gaseous phase (boiling) in the high-temperature section of the heat pipe and releases heat to a heat bath by changing from a gaseous to a liquid phase (condensing) in the low-temperature section of the heat pipe (see, for example, JP 2014-47 979 A). Heat pipes have the advantage that they can be operated without an electrical supply (without any work being supplied).

[0004] In heat transfer devices of type (B), a liquid is usually used as the heat transfer medium, with cooling with water being particularly effective for cooling below the boiling point. JP 2009 - 74 722 A, JP 2005 - 201 623 A and EP 0 488 942 A2 each disclose heat transfer devices with features of claim 1. SUMMARY Technical Problem

[0005] Against this background, heat pipes, which are a representative example of heat transfer devices of type (A), have the problem that the heat pipe is not operated when there is a small temperature difference between the heat source (the high-temperature section) and the low-temperature section, and that it dries out when there is a large temperature difference.

[0006] Furthermore, if the heat source has a high temperature (e.g., 500 °C), it becomes difficult to choose a working fluid that remains liquid at that high temperature. This problem is solved by using a metal (e.g., sodium) as the working fluid; however, due to its physical properties, there is a risk of explosion.

[0007] Furthermore, if the temperature of the heat source decreases gradually due to heat transfer, it is difficult to use a heat pipe, since it is assumed that the heat transfer performance of a heat pipe designed to efficiently transfer heat at an initial temperature (e.g. 500 °C) decreases with decreasing temperature because the temperature that causes the phase change in the working fluid is fixed.

[0008] If a liquid is used as the heat transfer medium in heat transfer devices of type (B), there is a risk that the heat transfer medium will explode in the same way in a heat pipe if the heat source has a high temperature (e.g. 500 °C).

[0009] If a gas is chosen as the heat transfer medium, it can also be used when the heat source has a high temperature. However, it is necessary to ensure that the heat transfer medium (inert gas) circulates in the closed space, as there is no driving force resulting from a phase change. Furthermore, the heat transfer medium reaches a high temperature, consequently requiring an expensive pump that is pressure- and heat-resistant (resistant to high temperatures). Therefore, when a gas is chosen as the heat transfer medium, the problem arises that the commissioning costs are high, and the pump also incurs operating and maintenance costs, etc.

[0010] The present disclosure provides a heat transfer device that is very safe and can be manufactured and operated cost-effectively, and a furnace that is operated by it. Solution to the problem

[0011] A first aspect of the disclosure relates to a heat transfer device comprising (i) a housing extending over a high-temperature heat source and a low-temperature heat bath having a lower temperature than the high-temperature heat source; comprising a closed space in which non-condensing gas is enclosed, wherein a conduit is formed in the housing and both end sections of the conduit are sealed;(ii) a regenerator arranged in the conduit and provided with pores connecting the two end sections of the regenerator and insulated from the outside of the casing, (iii) a first heat exchanger arranged in the conduit next to the end section of the regenerator on the high-temperature heat source side and enabling the heat from the high-temperature heat source to be conducted towards the regenerator, and (iv) a second heat exchanger arranged in the conduit next to the end section of the regenerator on the low-temperature heat bath side and enabling the heat from the regenerator to be conducted towards the low-temperature heat bath, the center of the regenerator being located along the direction of extension of the conduit at a position in the conduit between 12.5% ​​and 25% of the conduit length from the end section of the conduit on the high-temperature heat source side.

[0012] According to the first aspect, the gas is enclosed in the housing, which extends over the high-temperature heat source side and the low-temperature heat bath and encompasses the enclosed space, with the conduit being formed in the housing, both end sections of which are sealed.Arranged in the conduit are the regenerator, which is insulated from the outside of the casing and in which the pores are formed that connect the two end sections of the regenerator, the first heat exchanger, which is arranged next to the end section of the regenerator on the high-temperature heat source side (hereinafter referred to as the "first end section") and allows the heat from the high-temperature heat source to be transferred to the regenerator, and the second heat exchanger, which is arranged next to the end section of the regenerator on the low-temperature heat bath side (hereinafter referred to as the "second end section") and allows the heat from the regenerator to be transferred to the low-temperature heat bath.

[0013] Therefore, if a temperature gradient is generated in the regenerator from the first end section to the second end section, and the temperature ratio between the first and second end sections exceeds a threshold value, the gas in the pores of the regenerator is subjected to self-excited thermoacoustic vibrations. Consequently, a standing wave is generated in the pipe.

[0014] Here, the center of the regenerator is arranged along the extension direction of the line at a position in the line that is between 12.5% ​​and 25% of the line length from the end section of the line on the high-temperature heat source side; consequently, the regenerator is arranged such that the pressure amplitude of the standing wave (in a 1 / 2-wavelength mode) of the self-excited thermoacoustic wave decreases monotonically from the first end section to the second end section.

[0015] Therefore, it is possible to transfer heat from the first end section to the second end section in the regenerator through heat exchange between the gas in the pores of the regenerator and the porous wall sections. Since the regenerator is located in the pipeline at the position described above, the product of the pressure amplitude and the velocity amplitude of the standing wave increases. Consequently, the heat transfer power achieved by the regenerator is further increased.

[0016] This means that the heat from the high-temperature heat source can be efficiently transferred to the low-temperature heat bath via the first heat exchanger, the regenerator, and the second heat exchanger.

[0017] It should be noted that this heat transfer device does not require a drive source, consequently there are no operating and maintenance costs, the device can be manufactured and operated cost-effectively and does not require a phase change from gaseous to liquid, making it very safe compared to heat transfer devices with a phase change.

[0018] A second aspect of the disclosure relates to a heat transfer device, wherein the conduit according to the first aspect comprises: (i) an inner tube, part of which connects the high-temperature heat source side to the low-temperature heat bath side in the casing, and (ii) an outer tube arranged on the outside of the inner tube, which is connected to the inner tube on the low-temperature heat bath side, wherein an end section on the high-temperature heat source side of the outer tube is closed and the first heat exchanger, the second heat exchanger and the regenerator are arranged in the outer tube.

[0019] According to the second aspect, part of the conduit has a double-pipe structure comprising the inner pipe and the outer pipe formed on the outside of the inner pipe, with the end section of the outer pipe being closed on the high-temperature heat source side. Furthermore, the regenerator, the first heat exchanger, and the second heat exchanger are arranged within the outer pipe, with the outer and inner pipes connected at the end section on the low-temperature heat bath side. That is, inside the casing, a conduit extends from the end section (the closed section) of the outer pipe on the high-temperature heat source side, through the outer pipe, the end section of the casing on the low-temperature heat bath side, and the inner pipe, to the end section of the casing on the high-temperature heat source side.

[0020] Therefore, if a temperature gradient is generated in the regenerator located in the outer pipe from the first end section to the second end section, and the temperature ratio between the first and second end sections exceeds the threshold value, the gas in the pores of the regenerator is subjected to self-excited thermoacoustic vibrations. Consequently, a standing wave is generated in the pipe.

[0021] Here, the center of the regenerator is arranged along the extension direction of the line at a position in the line that is between 12.5% ​​and 25% of the line length from the end section of the line on the high-temperature heat source side (the sealed section of the outer pipe), consequently the regenerator is arranged such that the pressure amplitude of the standing wave (in a 1 / 2-wavelength mode) of the self-excited thermoacoustic wave decreases monotonically from the first end section to the second end section.

[0022] Therefore, heat can be transferred from the first end section to the second end section within the regenerator through heat exchange between the gas in the regenerator's pores and the porous wall sections. Since the regenerator is positioned in the pipeline at the location described above, the product of the pressure amplitude and the velocity amplitude of the standing wave is increased. Consequently, the heat transfer efficiency is maximized.

[0023] This means that the heat from the high-temperature heat source can be efficiently transferred to the low-temperature heat bath via the first heat exchanger, the regenerator, and the second heat exchanger.

[0024] It should be noted that this heat transfer device does not require a drive source, consequently there are no operating and maintenance costs, the device can be manufactured and operated cost-effectively and does not require a phase change from gaseous to liquid, making it very safe compared to heat transfer devices with a phase change.

[0025] Since the conduit extends from the end section of the outer tube on the high-temperature heat source side, through the end section of the casing on the low-temperature heat bath side, and the inner tube to the end section of the casing on the high-temperature heat source side, the volume of the casing protruding on the low-temperature heat bath side can be reduced. That is, if this heat transfer device is used as a heat dissipation device, the volume of the section protruding from the high-temperature heat source, such as a furnace, can be reduced.

[0026] A third aspect of the disclosure relates to the first or second aspect, wherein the heat transfer device is provided with a control unit which is arranged at the end section of the housing on the low-temperature heat bath side, so that it is movable forwards and backwards inside the housing and converts the waveform of a standing wave generated by the self-excited thermoacoustic wave in the line by moving forwards inside the housing.

[0027] According to the third aspect, the waveform (wavelength and amplitude) of the standing wave, generated by the self-excited thermoacoustic wave in the conduit, is modified by the control device, which moves back and forth relative to the interior of the casing, in a 1 / 2-wavelength mode. For example, if the waveform of the standing wave is modified by inserting the control device so that the pressure amplitude (the product of the pressure amplitude and the velocity amplitude) of the standing wave changes at the regenerator position, the amount of heat transfer can be regulated. Alternatively, the generation of the self-excited thermoacoustic wave in the regenerator can be stopped when the pressure amplitude no longer decreases monotonically from the first end section to the second end section of the regenerator, thus stopping the heat transfer of the heat transfer device.

[0028] A fourth aspect of the disclosure relates to a furnace comprising: (i) a furnace wall consisting of insulation, (ii) a heating device arranged inside the furnace bounded by the furnace wall, which heats the interior of the furnace, and (iii) the heat transfer device according to the first to third aspects, wherein the regenerator is arranged on the furnace wall, the first heat exchanger is arranged inside the furnace, and the second heat exchanger is arranged outside the furnace, at least when the furnace is cooling.

[0029] According to the fourth aspect, a difference arises between the temperature inside the furnace, which has been raised by the heating device, and the temperature outside the furnace. At least when the furnace is being cooled, the regenerator of the heat transfer device with which the furnace is equipped is arranged on the furnace wall, with the first heat exchanger being located inside the furnace, which has a high temperature, and the second heat exchanger being located outside the furnace, which has a low temperature.Therefore, if the temperature ratio between the two end sections (the first end section (the end section on the side of the first heat exchanger) and the second end section (the end section on the side of the second heat exchanger)) of regenerator 18 exceeds the threshold value due to the temperature difference between the inside and outside of the furnace, self-excited thermoacoustic oscillations are generated in the regenerator. These self-excited thermoacoustic oscillations, in turn, generate a standing wave in the duct of the heat transfer device. Furthermore, since the center of the regenerator is located at a position in the duct between 12.5% ​​and 25% of the duct length from the end section on the high-temperature heat source side (inside the furnace), the pressure amplitude decreases monotonically from the first heat exchanger to the second heat exchanger.Consequently, the heat is efficiently transferred from the first heat exchanger to the second heat exchanger. That is, the heat inside the furnace is efficiently transferred to the outside by the heat transfer device.

[0030] Furthermore, since the heat transfer device intended for cooling the furnace does not require a drive source, there are no operating and maintenance costs; consequently, the device can be manufactured and operated cost-effectively in the furnace, and no phase change from gaseous to liquid is required, making the device very safe compared to heat transfer devices with a phase change.

[0031] A fifth aspect of the revelation concerns an oven, the oven also comprising, according to the fourth aspect, a reflector that reflects the radiation inside the oven so that it hits the heat transfer device provided inside the oven.

[0032] According to the fifth aspect, as the oven cools, the radiation inside is reflected by the reflector and strikes the heat transfer device, thus efficiently heating the first heat exchanger of the heat transfer device. This means that the heat inside the oven is transferred to the outside even more efficiently by the heat transfer device.

[0033] A sixth aspect of the revelation concerns an oven, with the oven, according to the fifth aspect, also comprising a wave body that supports the reflector inside the oven and extends from the inside of the oven outwards.

[0034] According to the sixth aspect, the wave body passing through the furnace wall supports the reflector, so that the reflector can be positioned at any location inside the furnace.

[0035] A seventh aspect of the revelation concerns a furnace, wherein, according to the sixth aspect, the reflector is integral with the wave body and rotatable about the axial direction of the wave body.

[0036] According to the seventh aspect, the reflector can be rotated on the wave body. Therefore, when the oven is heated, the reflector points, for example, in the direction where the reflected radiation from the heating device cannot reach the heat transfer device. Thus, as the temperature inside the oven rises, a situation is prevented in which the radiation from the heating device reaches the heat transfer device via the reflector and the heat inside the oven is transferred to the outside through thermal conduction via the heat transfer device, which extends from the inside of the oven to the outside. Consequently, heating the inside of the oven (increasing the temperature) can be carried out efficiently.

[0037] Alternatively, when the oven is heated, the reflector can be positioned so that the heating element's radiation is reflected and directed onto the workpiece. Consequently, the heating element's radiation reaches the workpiece efficiently, thus increasing the heating efficiency.

[0038] When the oven cools, the reflector points in the direction in which it reflects the radiation inside the oven so that it strikes the heat transfer device, thus concentrating the radiation inside the oven and allowing it to reach the heat transfer device. Consequently, the heat inside the oven can be efficiently transferred to the heat transfer device via radiation.

[0039] Furthermore, if the reflector is rotated around the axis of the wave body during the cooling of the oven, heat can be directed by radiation from a large area inside the oven to the heat transfer device, so that the inside of the oven is cooled evenly.

[0040] In this way, the heating power can be increased when heating the oven by preventing heat from being released from the oven via the heat transfer device, and when cooling the oven, it can be efficiently cooled by means of the standing wave of the self-excited thermoacoustic vibrations in the heat transfer device.

[0041] An eighth aspect of the disclosure relates to an oven, wherein an opening section is formed in the wave body according to the sixth or seventh aspect, which extends in the axial direction of the wave body, wherein the heat transfer device is arranged in the opening section and the end section of the heat transfer device on the side on which the first heat exchanger is arranged is exposed to a reflective surface of the reflector at least when cooling the oven.

[0042] If the end section of the heat transfer device, located in the opening of the wave body, is exposed to the reflecting surface of the reflector as described above, the radiation inside the furnace can be more easily reflected by the reflecting surface and strike the end section of the heat transfer device. This allows the radiation inside the furnace to be concentrated and directed onto the end section of the heat transfer device. Consequently, the side of the first heat exchanger of the heat transfer device is heated, and heat from inside the furnace can be efficiently transferred to the first heat exchanger. As a result, the furnace can be cooled efficiently.

[0043] A ninth aspect of the revelation relates to an oven, wherein, according to the eighth aspect, a part of the end section of the heat transfer device on the side on which the first heat exchanger is arranged is positioned in a focus of the reflecting surface of the reflector, at least when the oven is cooling.

[0044] According to the ninth aspect, part of the heat transfer device is located at the focal point of the reflector's reflective surface. Consequently, during cooling, the radiation inside the furnace is reflected by the reflector and strikes the part of the heat transfer device located at the focal point of the reflector's reflective surface. This means the reflected radiation inside the furnace is further concentrated and strikes the end section of the heat transfer device on the side of the first heat exchanger. As a result, the heat inside the furnace is transferred even more efficiently to the heat transfer device and released to the outside.

[0045] A tenth aspect of the revelation concerns a furnace, wherein the reflector, according to the eighth or ninth aspect, is integrally movable forwards and backwards with the wave body in relation to the furnace wall along the axial direction.

[0046] According to the tenth aspect, as the furnace heats up, the wave body is moved forward inside the furnace, i.e., in the direction in which the reflector is moved away from the furnace wall, thus accommodating the first heat exchanger of the heat transfer device inside (in the opening section) of the wave body. This prevents a rise in the temperature of the first heat exchanger of the heat transfer device located inside the furnace and keeps the temperature ratio between the two end sections of the regenerator at or below the threshold value. Consequently, this prevents the generation of self-excited thermoacoustic vibrations in the regenerator of the heat transfer device, which in turn prevents heat loss through self-excited thermoacoustic vibrations in the heat transfer device.This prevents heat loss during the heating of the oven, thus increasing the efficiency with which the oven is heated.

[0047] As the furnace cools, the wave body is removed (displaced) from the furnace in the same direction as the reflector moves towards the furnace wall. This exposes the end section of the heat transfer device housing, on the side of the first heat exchanger, to the reflector's reflective surface. Consequently, the radiation inside the furnace is reflected by the reflector's surface and strikes the end section of the heat transfer device housing on the side of the first heat exchanger. This means the heat inside the furnace is transferred even more efficiently to the heat transfer device and dissipated to the outside through self-excited thermoacoustic vibrations.

[0048] According to an eleventh aspect of the revelation - in the fourth to tenth aspects - the heat transfer device is movable forwards and backwards in relation to the furnace wall along the axial direction of the heat transfer device.

[0049] According to the eleventh aspect, the heat transfer device is moved out of the furnace during heating, so that it is located at least as far as the first heat exchanger in the furnace wall. Consequently, the first heat exchanger of the heat transfer device is prevented from being directly heated by radiation inside the furnace during heating. Thus, the temperature ratio between the two end sections of the regenerator of the heat transfer device is kept below the threshold, and the generation of self-excited thermoacoustic vibrations in the regenerator is prevented, which in turn prevents heat from being conducted out of the furnace via the heat transfer device. As a result, the furnace can be heated efficiently.

[0050] During the cooling of the furnace, the heat transfer device inside the furnace is moved so that the portion of the heat transfer device from the first heat exchanger to the end section is exposed to the reflector's reflective surface. Consequently, the radiation inside the furnace is reflected by the reflector and efficiently heats the end section of the heat transfer device exposed to the reflective surface. As a result, the first heat exchanger of the heat transfer device is efficiently heated, and the temperature ratio between the two end sections of the regenerator exceeds the threshold, allowing the heat inside the furnace to be efficiently dissipated to the outside.

[0051] A twelfth aspect of the revelation concerns a furnace wherein - according to the fourth to eleventh aspects - the plate thickness of the casing from the position where the radiation hits the interior of the furnace to the position where the first heat exchanger is located is locally greater than the plate thickness of the other areas of the casing.

[0052] According to the twelfth aspect, during cooling, the radiation inside the furnace is reflected by the reflector and strikes the portion of the heat transfer device housing from the first heat exchanger to the end section. The housing of the heat transfer device is heated by the incident radiation. The thickness of the housing plates is locally greater from the point where the radiation strikes inside the furnace to the point where the first heat exchanger is located, thus increasing the heat conduction capacity within the heat transfer device. The heat supplied to the heat transfer device can then be efficiently transferred by radiation to the first heat exchanger. Consequently, the heat inside the furnace can be efficiently dissipated to the outside.

[0053] A thirteenth aspect of the revelation concerns a furnace, wherein - according to the fourth to twelfth aspects - the section of the casing on the outer circumferential side of the first heat exchanger consists of a radiation-transmitting element.

[0054] According to the thirteenth aspect, during cooling, the radiation inside the furnace strikes the casing of the heat transfer device directly, or after being reflected by the reflector. The radiation then passes through the section of the casing containing the first heat exchanger, which is located at the point where the first heat exchanger is situated, and reaches the first heat exchanger. That is, because the radiation inside the furnace strikes the first heat exchanger directly or after reflection by the reflector, the heat inside the furnace is transferred to the first heat exchanger without thermal conduction within the heat transfer device. Consequently, the heat inside the furnace can be dissipated to the outside even more efficiently. BRIEF DESCRIPTION OF THE DRAWINGS Fig. Figure 1 is a general configuration diagram of a heat transfer device according to a first embodiment. Fig. Figure 2 is a graph illustrating a positional relationship between a regenerator and the pressure amplitude of a standing wave in a 1 / 2 wavelength mode, which has been generated inside the heat transfer device according to the first embodiment. Fig. Figure 3 is a general configuration diagram illustrating a state in which a control valve shuts off an inner tube of the heat transfer device according to the first embodiment. Fig. Figure 4 is a graph illustrating the positional relationship between the regenerator and the pressure amplitude of the standing wave in 1 / 2-wavelength mode, which is generated inside the heat transfer device when the inner tube is sealed. Fig. Figure 5 is a general configuration diagram illustrating a state in which the control valve regulates a length of pipe in the heat transfer device according to the first embodiment. Fig. Figure 6 is a graph illustrating the positional relationship between the regenerator and the pressure amplitude of the standing wave in 1 / 2-wavelength mode, which is generated inside the heat transfer device when the line length is regulated. Fig. Figure 7 is a general explanatory representation of an example in which an oven is provided with the heat transfer device according to the first embodiment. Fig. Figure 8A is a schematic representation illustrating heat transfer when the temperature is increased in the example where the oven is equipped with the heat transfer device according to the first embodiment. Fig. Figure 8B is a schematic representation illustrating heat transfer when the temperature is maintained in the example where the oven is equipped with the heat transfer device according to the first embodiment. Fig. Figure 8C is a schematic representation illustrating heat transfer when, in the example where the oven is equipped with the heat transfer device according to the first embodiment, the temperature is reduced. Fig. Figure 9A is a schematic diagram illustrating heat transfer when the temperature is increased in an oven according to a comparative example. Fig. Figure 9B is a schematic diagram illustrating heat transfer when the temperature is maintained in the oven according to a comparative example. Fig. Figure 9C is a schematic diagram illustrating heat transfer when the temperature in the oven is lowered according to a comparative example. Fig. Figure 10 is a general configuration diagram of a heat transfer device according to the second embodiment. Fig. Figure 11 is a general explanatory representation of an example in which an oven is provided with the heat transfer device according to the second embodiment. Fig. Figure 12 is a graph illustrating numerical calculation results and experimental results of the relationship between the position of the regenerator inside the heat transfer device according to the second embodiment, the thermal efficiency and the amount of heat transferred. Fig. Figure 13 is a general perspective drawing illustrating an oven according to the third embodiment in the state in which the oven is being heated. Fig. Figure 14 is an exploded perspective view of a reflector unit and the heat transfer device according to the third embodiment. Fig. Figure 15 is an enlarged sectional view illustrating the positional relationship between the reflector unit, the heat transfer device and a heating device in the state in which the furnace is heated according to the third embodiment. Fig. Figure 16 is a sectional view illustrating the oven according to the third embodiment in the state in which the oven is being heated. Fig. Figure 17 is a general perspective representation illustrating the furnace according to the third embodiment in the state in which the furnace is being cooled. Fig. Figure 18 is an enlarged sectional view illustrating the positional relationship between the reflector unit, the heat transfer device and the heating device in the state in which the furnace is cooled according to the third embodiment. Fig. Figure 19 is a sectional view illustrating the oven according to the third embodiment in the state in which the oven is being cooled. Fig. Figure 20 is an enlarged sectional view illustrating the positional relationship between the reflector unit, the heat transfer device and the heating device in the state in which the furnace is heated according to another example of the third embodiment. Fig. Figure 21 is a sectional view illustrating the oven in the state in which the oven is being heated, according to the further example of the third embodiment. Fig. Figure 22 is an enlarged sectional view illustrating the positional relationship between the reflector unit, the heat transfer device and the heating device in the state in which a furnace is heated according to a fourth embodiment. Fig. Figure 23 is an enlarged sectional view illustrating the positional relationship between the reflector unit, the heat transfer device and the heating device in the state in which the furnace is cooled according to the fourth embodiment. Fig. Figure 24 is an enlarged sectional view of relevant parts, illustrating the positional relationship between the reflector unit and the heat transfer device in the state in which the furnace is cooled according to another example of the fourth embodiment. Fig. Figure 25 is a general perspective representation illustrating an oven according to a fifth embodiment in the state in which the oven is being heated. Fig. Figure 26 is a sectional view illustrating the oven according to the fifth embodiment in the state in which the oven is being heated. Fig. Figure 27 is a sectional view illustrating the furnace according to the fifth embodiment in the state in which the furnace is being cooled. Fig. Figure 28 is a sectional view illustrating the oven in the state in which the oven is being heated, according to another example of the fifth embodiment. DESCRIPTION OF THE DESIGNS

[0055] The embodiments of the disclosure are described in detail below with reference to the drawings. First, a heat transfer device according to a first embodiment and an example in which a furnace is equipped with the heat transfer device are described. Then, a heat transfer device according to a second embodiment and an example in which a furnace is equipped with the heat transfer device are described. Furthermore, furnaces according to third to fifth embodiments, which are equipped with the heat transfer device according to the first embodiment, are described. First configuration (arrangement of the device)

[0056] First, a heat transfer device 10 according to the disclosure is described with reference to the Fig. 1 described. The heat transfer device 10 comprises a tubular body 12, i.e. a housing in the form of a hollow cylinder, a first heat exchanger 14 and a second heat exchanger 16 arranged inside the tubular body 12, a regenerator 18 arranged between the first heat exchanger 14 and the second heat exchanger 16 inside the tubular body 12, and a control valve 20 mounted so that it is movable forwards and backwards with respect to the interior of the tubular body 12. (Tubular body 12)

[0057] The tubular body 12 has the form of a hollow cylinder, the interior of which is designed as a closed space. The interior of the tubular body 12 is filled with a gas, such as nitrogen gas.

[0058] The tubular body 12 extends axially from a first end section 12A at one end to a second end section 12B at the other end, with an inner tube 22, which is coaxial with the tubular body 12 and has a smaller diameter than the tubular body 12, formed in an axial direction section. Both end sections of the inner tube 22 are open, with the inner tube 22 connecting the side of the first end section 12A and the side of the second end section 12B of the tubular body 12.

[0059] Furthermore, for the sake of simplicity, the section bounded by the inner tube 22 and the part of the tubular body 12 that is positioned on the radially outer side of the inner tube 22 are referred to as the outer tube 24.

[0060] The end section of the outer tube 24 on the side of the first end section 12A is closed by a closed surface 26, and the end section of the outer tube 24 on the side of the second end section 12B is open to the side of the second end section 12B of the tubular body 12. That is, the inner tube 22 and the outer tube 24 are connected to each other on the side of the second end section 12B of the tubular body 12. Consequently, a conduit X is formed in the tubular body 12, extending from the closed surface 26 of the outer tube 24, across the outer tube 24, the side of the second end section 12B of the tubular body 12, and the inner tube 22 to the first end section 12A of the tubular body 12, with both end sections of the conduit being closed. L0 denotes the length of the line X (line length) along the line X from the closed area 26 to the first end section 12A.

[0061] Furthermore, the first heat exchanger 14, the regenerator 18 and the second heat exchanger 16 are arranged in series inside the outer tube 24 from the side of the first end section 12A to the side of the second end section 12B.

[0062] The side of the first end section 12A of the tubular body 12 is located in a high-temperature heat source 28 up to the position of the first heat exchanger 14 in the axial direction. The side of the second end section 12B of the tubular body 12 is located in a low-temperature heat bath 30, which has a lower temperature than the high-temperature heat source 28, up to the position of the second heat exchanger 16 in the axial direction.

[0063] It should be noted that in the present embodiment, ‘high-temperature heat source’ refers to the external environment from which the heat transfer device 10 is supplied with heat, and ‘low-temperature heat bath’ refers to the external environment into which the heat transfer device 10 releases heat.

[0064] Furthermore, the section (the outer circumference) of the tubular body 12 where the regenerator 18 is located is provided with an insulating element 32. Consequently, the regenerator 18 is insulated from the outside of the tubular body 12.

[0065] Furthermore, the control valve 20 described below is arranged on the side of the second end section 12B of the tubular body 12. (First heat exchanger 14)

[0066] As in Fig. As shown in Figure 1, the first heat exchanger 14 has the shape of a ring, filling the cross-section of the outer tube 24, and is located on the side of the first end section 12A next to the regenerator 18 in the outer tube 24. Furthermore, the first heat exchanger 14 is located in the high-temperature heat source 28. The first heat exchanger 14 enables the heat from the high-temperature heat source 28 to be transferred to the regenerator 18; in one example, it enables heat transfer because a working fluid flows inside it, and in another example, it enables heat transfer by radiation or conduction without a fluid flow. (Second heat exchanger 16)

[0067] As in Fig. As shown in Figure 1, the second heat exchanger 16 has the shape of a ring, filling the cross-section of the outer tube 24, and is located on the side of the second end section 12A next to the regenerator 18 in the outer tube 24. Furthermore, the second heat exchanger 16 is located in the low-temperature heat bath 30. That is, the second heat exchanger 16 enables the heat from the regenerator 18 to be transferred to the low-temperature heat bath 30, either by means of a working fluid flowing within it or by radiation or conduction. (Regenerator 18)

[0068] As in Fig. As shown in Figure 1, the regenerator 18 is a structure 33 which has the shape of a ring, so that it fills the cross-section of the outer tube 24, wherein numerous pores 34 are formed in the structure 33 which run along the axial direction from the side of the first end section 12A to the side of the second end section 12B.

[0069] The diameter of the pores 34 is dimensioned such that the dimensionless channel diameter r = R / D is approximately 2. Here, R denotes the diameter of the pores 34 and D denotes the thickness of the thermal boundary layers formed inside the pores 34.

[0070] As in Fig. 1 and Fig. As shown in Figure 2, the regenerator 18 is also arranged in the outer tube 24, so that its center is positioned in the direction in which the line extends (the axial direction) at a position in the line which is 25% (0.25L0) of the line length L0 from the closed surface 26.

[0071] Although the structure 33 of the regenerator 18 in the present embodiment has numerous pores 34 extending along the axial direction from the side of the first end section 12A to the side of the second end section 12B, it can also have a configuration in which hole sections are formed extending from the side of the first end section 12A to the side of the second end section 12B along the axial direction by laminating a plurality of plate-like stacks, each containing a porous medium in which numerous hole sections are formed extending from the end surface on the side of the first end section 12A to the end surface on the side of the second end section 12B. These hole sections are also contained in the pores of the disclosure. (Control valve 20)

[0072] The control valve 20 has a valve body 36, which is arranged in the tubular body 12 and has the shape of a conical tip pointing towards the side of the first end section 12A, and a shaft body 38, which extends axially from the end section of the valve body 36 to the side of the second end section 12B. The valve body 36 is dimensioned such that, due to its diameter, it is able to close the end section of the inner tube 22. The shaft body 38 extends outside the tubular body 12 from a hole section 39 formed in the second end section 12B of the tubular body 12. Furthermore, the shaft body 38 can be moved forwards and backwards in the axial direction by means of a drive device (not shown in the drawings). That is, the valve body 36, which is attached to the distal end of the shaft body 38, can be moved forwards and backwards inside the tubular body 12. (Operation)

[0073] The operation of the heat transfer device 10 is described below.

[0074] In the heat transfer device 10, the regenerator 18, which - as in Fig. As shown in Figure 1, a temperature gradient is generated between the first heat exchanger 14, located in the high-temperature heat source 28, and the second heat exchanger 16, located in the low-temperature heat bath 30. When the ratio (temperature ratio) between the temperature of the end section of the regenerator 18 on the side of the first end section 12A (i.e., the high-temperature side) and the temperature of the end section of the regenerator 18 on the side of the second end section 12B (i.e., the low-temperature side) exceeds a threshold value, the gas in the pores 34 of the regenerator 18 is subjected to self-excited thermoacoustic vibrations.

[0075] The self-excited thermoacoustic vibrations generate a standing wave inside the tubular body 12, specifically in the line X, which extends from the closed surface 26 of the outer tube 24 to the side of the second end section 12B of the tubular body 12 and from the side of the second end section 12B via the inner tube 22 to the first end section 12A.

[0076] Fig. Figure 2 illustrates a case in which a standing wave is generated in a 1 / 2 wavelength mode in the duct of the tubular body 12. Fig. In Figure 2, the x-axis represents the distance from the closed surface 26 in the conduit. Here, L0 is the conduit length from the closed surface 26 to the first end section 12A of the tubular body 12.

[0077] In this context, the in Fig. 2 Regenerator 18 arranged below the x-axis represents the position of the regenerator in the line, in particular its positional relationship with the standing wave.

[0078] That is, if - as in Fig. 2 shown - inside the tubular body 12 the standing wave has been generated, the distance from the closed surface 26 to the center of the regenerator 18 in the extension direction of the line (the axial direction) is 0.25L0 with respect to the line length L0, consequently the regenerator 18 is arranged in the section where the product of the pressure amplitude and the velocity amplitude is greatest and the heat transfer quantity is maximized.

[0079] Therefore, if a temperature gradient is generated in the regenerator 18 of the heat transfer device 10 according to the present embodiment, and the temperature ratio between the two end sections of the regenerator 18 exceeds the threshold value, self-excited thermoacoustic oscillations are generated, and corresponding to these self-excited thermoacoustic oscillations, a standing wave is also generated in the tubular body 12. Since the center of the regenerator 18 is located in the direction of extension of the conduit at a position in the conduit that is 25% (0.25L0) of the conduit length L0 from the closed surface 26, the pressure amplitude of the standing wave decreases monotonically from the high-temperature side to the low-temperature side of the regenerator 18, so that heat can be transferred from the high-temperature side to the low-temperature side inside the regenerator 18.The heat from the high-temperature heat source 28 is transferred to the low-temperature heat bath 30 via the first heat exchanger 14, the regenerator 18 and the second heat exchanger 16.

[0080] Furthermore, since the center of the regenerator 18 is located in the direction of extension of the conduit at a position 0.25L0 from the closed surface 26, the center of the regenerator 18 is positioned where the product of the pressure amplitude and the velocity amplitude of the standing wave reaches its maximum value, and the amount of heat transfer through the regenerator 18 is maximized. Consequently, the heat transfer device 10 can efficiently transfer heat from the high-temperature heat source 28 to the low-temperature heat bath 30.

[0081] Furthermore, part of the tubular body 12 of the heat transfer device 10 has a double-tube structure with the inner tube 22 and the outer tube 24, wherein the conduit X extends from the end section of the outer tube 24 on the high-temperature heat source side (the closed surface 26) to the end section of the tubular body 12 on the high-temperature heat source side (the first end section 12A). Consequently, the portion of the total volume of the tubular body 12 occupied by the volume of the section of the tubular body 12 that projects on the side of the low-temperature heat bath 30 is reduced. That is, the volume of the section of the tubular body 12 that protrudes on the side of the high-temperature heat source 28 becomes larger, thereby increasing the area of ​​heat transfer from the high-temperature heat source 28 to the tubular body 12, thus further increasing the heat transfer performance of the heat transfer device 10.

[0082] If the temperature difference between the end section of regenerator 18 on the high-temperature side and the end section of regenerator 18 on the low-temperature side significantly exceeds the threshold, a standing wave in a 1-wavelength mode is sometimes generated in line X, caused by a self-excited acoustic wave. In this case, heat transfer in regenerator 18 also occurs due to the standing wave in the 1-wavelength mode, and the heat transfer performance of the heat transfer device 10 is further increased.

[0083] Since the heat transfer device 10 utilizes self-excited thermoacoustic vibrations, heat transfer occurs without a drive source (electrical supply), such as a pump. Consequently, the manufacturing and operating costs of the heat transfer device 10 can be reduced. Furthermore, the heat transfer device 10 is maintenance-free, as heat transfer does not require a drive source.

[0084] In the gaseous form of the heat transfer device 10, the nitrogen gas enclosed inside the tubular body 12 is also used. Thus, no phase change from liquid to gaseous state is required, and there is no risk of the working fluid (in this embodiment, the nitrogen gas) exploding, making the heat transfer device 10 very safe.

[0085] In the heat transfer device 10, the valve body 36 can also be moved towards and away from the end section side of the inner tube 22 when driven by a drive source (not shown) of the control valve 20. When the valve body 36 reaches the end section (the open section) of the inner tube 22 – as shown in Fig. As shown in Figure 3, when closed, the line X, in which the standing wave is generated, is shortened from the closed surface 26 to the valve body 36. That is, the line length is reduced from L0 to L1.

[0086] As in Fig. As shown in Figure 4, the waveform (wavelength) of the standing wave is shortened in half-wavelength mode, the relative position of the regenerator 18 with respect to the standing wave changes, and the relationship whereby the pressure amplitude decreases monotonically from the high-temperature side to the low-temperature side of the regenerator 18 no longer holds. That is, the self-excited thermoacoustic vibrations are no longer generated, even if a temperature gradient is created between the two end sections of the regenerator 18. Therefore, the heat transfer of the regenerator 18 is stopped.

[0087] As in Fig. As shown in Figure 5, the waveform (amplitude) of the standing wave can be changed by adjusting how far the control valve 20 is moved into the tubular body 12, i.e., how close it is to the end section of the inner tube 22, up to the point where the control valve 20 does not abut the end section of the inner tube 22. As shown in Fig. As shown in Figure 6, the overall pressure amplitude of the standing wave can be changed (e.g., reduced). Consequently, the product of the pressure amplitude and the velocity amplitude at the position where the regenerator 18 is located can be changed in order to regulate the amount of heat (thermal conductivity) transferred by the regenerator 18. (Applied example)

[0088] With reference to the Fig. 7 to Fig. Section 9C describes an example in which an industrial furnace 40 is equipped with the heat transfer device 10. The components of the heat transfer device 10, which do not differ from the embodiment described above, are assigned the same reference numerals, so they are not described in detail.

[0089] As in Fig. As shown in Figure 7, the furnace 40 has insulation 42 in the form of a rectangular body, forming an enclosed space, with parts of a heating device 44 and the heat transfer device 10 inserted into the interior of the furnace 40 from the upper wall. The heating device 44 is driven by a power source (not shown in the drawings) so that it heats a gas inside the insulation 42, raising the temperature inside the furnace 40 to a predetermined temperature and maintaining it at that temperature.

[0090] The heat transfer device 10 serves to transfer heat from the interior of the furnace to the outside in order to lower the temperature inside the furnace 40 after the heating process is complete. The side of the first end section 12A of the heat transfer device 10 is inserted into the interior of the furnace 40, and the side of the second end section 12B protrudes from the furnace 40. That is, in the axial direction of the heat transfer device 10 (the tubular body 12), the section from the first end section 12A of the tubular body 12 to the end section of the first heat exchanger 14 is inserted into the interior of the furnace 40, and the section from the end section of the second heat exchanger 16 to the second end section 12B is located outside the furnace 40. Furthermore, the regenerator 18 of the heat transfer device 10 is located at the position of the insulation 42 of the furnace 40.

[0091] The operation of the heat transfer device 10 arranged in the furnace 40 in this way is described by comparison with a furnace 46 of a comparative example which is not equipped with the heat transfer device 10.

[0092] The furnace 46 according to the comparative example is not equipped with a heat transfer device that releases heat, so that cooling inside the furnace, as in Fig. Figure 9C shows the temperature difference between the inside and outside of the oven due to natural heat radiation through the insulation 42. To increase the amount of heat Q23 due to natural heat radiation, it is conceivable to reduce the thickness of the insulation 42 and thus decrease its insulating properties. However, an increase in the amount of heat Q23 due to natural heat radiation leads to an increase in the amount of heat Q21 supplied to the oven by the heating device 44 when the temperature, as shown in Figure 9C, is increased. Fig. 9A is shown, and a quantity of heat Q22 is supplied to the furnace by the heating device 44 when the temperature, as shown in Fig. 9B, is maintained. Consequently, it is difficult to efficiently dissipate the heat inside the oven.

[0093] In contrast, in the case of oven 40, which is equipped with the heat transfer device 10, - as in Fig. As shown in Figure 8A, when the temperature inside the furnace 40 increases, the heating device 44 is activated and a quantity of heat Q11 is supplied to the furnace. Due to the temperature difference between the inside and outside of the furnace 40, a quantity of heat Q13 is drawn from the inside of the furnace. When the valve body 36 of the control valve 20 closes the end section of the inner tube 22 (see Figure 8A) Fig. 3) The self-excited thermoacoustic vibrations are not generated in the regenerator 18, so the heat transfer of the heat transfer device 10 is stopped. Consequently, the temperature inside the furnace 40 increases according to the difference between the amount of heat supplied Q11 and the amount of heat removed Q13.

[0094] If the temperature inside the oven is maintained at 40°C, as in Fig. As shown in Figure 8B, the heating device 44 is operated and a quantity of heat Q12 is supplied to the furnace, which is equal to the quantity of heat Q13 emitted by the furnace 40. In this case, the heat transfer of the heat transfer device 10 is therefore stopped. Consequently, the temperature inside the furnace 40 is kept constant.

[0095] Furthermore, the valve body 36 of the control valve 20 of the heat transfer device 10 is moved towards the second end section 12B of the tubular body 12 during the lowering of the temperature inside the furnace 40, thereby opening the end section of the inner tube 22 (see Fig. 1) As in Fig. As shown in Figure 8C, this generates self-excited thermoacoustic vibrations corresponding to the difference between the temperature inside and outside the oven 40, causing the heat transfer device 10 to transfer (release) a quantity of heat Q14 from the inside of the oven to the outside. In this way, the quantity of heat Q14 released by the heat transfer device 10 and the quantity of heat Q13 released by the insulation 42 through natural heat radiation are transported from the inside of the oven to the outside, thus efficiently reducing the temperature inside the oven.Moreover, the heat output is high compared to the case where only the natural heat radiation of the insulation 42 is present, as in the oven 46 of the comparison example; therefore, it is not necessary to reduce the thickness of the insulation 42 for heat radiation, so that the thermal efficiency remains high when raising the temperature and maintaining the temperature.

[0096] In the heat transfer device 10, a part of the tubular body 12 also has a double-tube structure with the inner tube 22 and the outer tube 24, wherein the regenerator 18, the first heat exchanger 14 and the second heat exchanger 16 are arranged in the outer tube 24, consequently the volume of the section of the tubular body 12 on the side of the second end section 12B, which is arranged outside the furnace 40, and its ratio in relation to the total volume is small, so that the heat transfer device 10 can be excellently attached to the existing furnace 40.

[0097] The volume of the section of the tubular body 10 of the heat transfer device 10 located inside the furnace is large, thus increasing the area of ​​heat transfer from the furnace 40 (the gas inside the furnace) in relation to the tubular body 12. Consequently, the efficiency with which the heat transfer device 10 transfers heat from the inside of the furnace to the outside is increased even further.

[0098] Moreover, the gas (nitrogen gas) that serves as the working fluid is enclosed inside the tubular body 12 of the heat transfer device 10, so that the gas inside the furnace and the gas in the heat transfer device 10 cannot mix and the environment inside the furnace is protected.

[0099] Furthermore, the nitrogen gas inside the heat transfer device 10 is used in its gaseous form, i.e., the heat transfer device 10 does not require a phase change from liquid to gaseous, so there is no risk of a gas explosion and the heat transfer device 10 is very safe, even when used in the industrial furnace 40, which has a high operating temperature (e.g. 500 °C). Second configuration (arrangement of the device)

[0100] With reference to the Fig. 10 describes a heat transfer device according to a second embodiment of the disclosure. The components that do not differ from those of the first embodiment are assigned the same reference numerals, without these components being described in detail; that is, only those points that differ from the first embodiment are described.

[0101] As in Fig. As shown in Figure 10, a heat transfer device 50 has a single-pipe structure, i.e., the double-pipe structure that partially formed the tubular body 12 of the heat transfer device 10 has been omitted. Consequently, in the heat transfer device 50, the line X extends from the first end section 12A to the second end section 12B of the tubular body 12. In the heat transfer device 50, the distance along the line (in the axial direction) from the first end section 12A to the control valve 20 on the side of the second end section 12B corresponds to the line length L0.

[0102] The first heat exchanger 14, the second heat exchanger 16, and the regenerator 18 are arranged throughout the entire cross-section of the tubular body 12. The regenerator 18 is positioned such that its center, in the direction in which the conduit extends (the axial direction), is located at a position X in the conduit that is 25% (0.25L0) of the conduit length L0 from the first end section 12A. Consequently, the axial length of the tubular body 12 located in the low-temperature heat bath 30 (the outer surface of the insulating element 32) is greater than the axial length of the tubular body 12 located in the high-temperature heat source 28.

[0103] In the heat transfer device 50, the control valve 20 is arranged at the second end section 12B of the tubular body 12. The valve body 52 of the control valve 20 has a disc shape that corresponds to the cross-sectional shape (e.g., circular shape) of the tubular body 12. Furthermore, the shaft body 38 of the control valve 20 can be moved forwards and backwards in the axial direction by means of a drive source (not shown in the drawings). That is, when the valve body 52 of the control valve 20 is moved forwards and backwards in the axial direction of the tubular body 12, the pipe length is regulated. (Operation)

[0104] The operation of the heat transfer device 50 is described below. It should be noted that the description regarding its operation, which does not differ from that of the heat transfer device 10, has been simplified or shortened.

[0105] In the heat transfer device 50, self-excited thermoelectric oscillations are generated inside the regenerator 18, and corresponding to the self-excited thermoacoustic oscillations, a standing wave is generated inside the tubular body 12. In the heat transfer device 50, the regenerator 18 is also arranged such that the pressure amplitude of the standing wave is directed from the high-temperature side to the low-temperature side (see Fig. 2) decreases monotonically, so that the heat can be transferred from the high-temperature heat source 28 to the low-temperature heat bath 30.

[0106] Furthermore, since the center of the regenerator 18 is located at a position in the line 0.25L0 from the first end section 12A, the center of the regenerator 18 is positioned where the product of the pressure amplitude and the velocity amplitude of the standing wave reaches its maximum value, thus maximizing the amount of heat transfer through the regenerator 18. Consequently, the heat transfer device 50 can efficiently transfer heat from the high-temperature heat source 28 to the low-temperature heat bath 30.

[0107] In the heat transfer device 50, the valve body 52 can also be moved towards and away from the side of the first end section 12A (of the second heat exchanger 16) of the tubular body 12 when driven by the actuator of the control valve 20 (not shown). This changes the length of the line X in which the standing wave is generated, thus changing the relative positional relationship between the standing wave and the regenerator 18. Consequently, the product of the pressure amplitude and the velocity amplitude at the position where the regenerator 18 is located can be changed to regulate the heat transfer rate of the heat transfer device 50 (of the regenerator 18).

[0108] Depending on the change in the relative positional relationship between the standing wave and the regenerator 18, the relationship whereby the pressure amplitude of the standing wave decreases monotonically from the high-temperature side to the low-temperature side of the regenerator 18 no longer holds. That is, the self-excited thermoacoustic vibrations are no longer generated, even if a temperature gradient is created in the regenerator 18. Therefore, the heat transfer of the heat transfer device 50 (of the regenerator 18) is stopped.

[0109] When the control valve 20 is moved forwards and backwards in the axial direction, the heat transfer in the heat transfer device 50 can be interrupted (the generation of the standing wave can be stopped), and the amount of heat transfer (thermal conductivity) can be regulated. (Applied example)

[0110] With reference to the Fig. Section 11 describes an example in which the industrial furnace 40 is equipped with the heat transfer device 50. The components of the heat transfer device 50 are assigned the same reference numerals as in the embodiment described above, without a detailed description of these components. Furthermore, the industrial furnace has the same construction as the furnace equipped with the heat transfer device 10; therefore, the same reference numerals are used without a detailed description.

[0111] In the heat transfer device 50 provided on the furnace 40, the side of the first end section 12A is inserted into the interior of the furnace 40, and the side of the second end section 12B protrudes from the furnace 40. That is, in the axial direction of the heat transfer device 50, the section from the first end section 12A to the end section of the first heat exchanger 14 is inserted into the interior of the furnace 40, and the section from the end section of the second heat exchanger 16 to the second end section 12B is located outside the furnace 40. Consequently, the regenerator 18 is located at the position of the insulation 42.

[0112] Since the heat transfer device 50 is arranged on the furnace 40 in this way, the self-excited thermoacoustic vibrations are generated in the regenerator 18 according to the temperature difference between the temperature inside the furnace 40 and the temperature outside the furnace 40, the standing wave is generated inside the tubular body 12, and the heat inside the furnace 40 is transferred from the first heat exchanger 14 via the regenerator 18 to the second heat exchanger 16 according to the gradient of the pressure amplitude of the standing wave.

[0113] In the heat transfer device 50, the first heat exchanger 14, the second heat exchanger 16 and the regenerator 18 are arranged inside the tubular body 12, which has a single-tube structure that is easy to manufacture.

[0114] Moreover, the heat transfer device 50 offers the advantage that the part of the tubular body 12 which is inserted into the interior of the furnace 40 can be reduced. [Experimental results and numerical calculation results]

[0115] In the heat transfer device with a single tube (the tubular body) according to the second embodiment, the thermal efficiencies (%) and heat transfer quantities (kW) were determined by numerical calculation based on a thermoacoustic theory with respect to heat transfer devices in which the position of the regenerator inside the tubular body was changed in the direction of extension of the line (see Fig. 12 and Kenta NAKAMURA and Yuki UEDA, "Design and Construction of a Standing-Wave Thermoacoustic Engine with Heat Sources Having a Given Temperature Ratio," Journal of Thermal Science and Technology, 2011, Vol. 6, No. 3, pp. 416-423).

[0116] Specifically, the diameter of the tubular body of the heat transfer device is 0.1 m, the total length is 3.5 m, and the axial length (the direction in which the conduit extends) of the regenerator inserted therein is 0.09 m. Furthermore, the temperature of the high-temperature heat source was set to 450 °C and the temperature of the low-temperature heat source to 60 °C.

[0117] Inside (the conduit) of the tubular body, a standing wave in 1 / 2-wavelength mode was generated, the pressure amplitude at the closed end (see the first end section 12A of the tubular body in Fig. 10) was set to 20 kPa, and the heat transfer quantity and the thermal efficiency were determined by numerical calculation, using as a parameter the distance from the closed end to the center of the regenerator in the axial direction.

[0118] Here, thermal efficiency is defined as work output / heat input. Furthermore, work output = heat input - heat output, i.e., thermal efficiency = (heat input - heat output) / heat input. Additionally, the amount of heat transferred equals the amount of heat input. That is, the amount of heat transferred is the amount of heat that reaches the regenerator from the high-temperature heat source via the first heat exchanger.

[0119] As in Fig. As shown in Figure 12, the thermal efficiency reaches a maximum value when the center of the regenerator is positioned at a 1 / 32 wavelength from the end section of the regenerator on the high-temperature side (the closed end), after which it gradually decreases.

[0120] The amount of heat transfer increases to the extent that the center of the regenerator is moved away from the end section on the high-temperature side, if the regenerator is arranged such that the center of the regenerator is positioned at a 1 / 48 wavelength from the end section of the regenerator on the high-temperature side.

[0121] Since it is desirable to increase the thermal efficiency of conventional thermoacoustic machines, the center of the regenerator is located in the Fig. The graphs shown in section 12 are positioned in a range from about 1 / 32 wavelength to about 3 / 64 wavelength from the end section of the line on the high-temperature side.

[0122] In contrast, the heat transfer device according to the present embodiment transfers heat, so it is desirable that the amount of heat transferred be as large as possible. The further the center of the regenerator is moved away from the end section of the line on the high-temperature side, the greater the amount of heat transferred; however, if the thermal efficiency is less than 1%, there is a risk that the self-excited thermoacoustic waves will no longer be generated due to heat radiation not taken into account in the numerical calculation. By positioning the center of the regenerator in the range of 1 / 16 wavelength to 1 / 8 wavelength (the range B in Fig. 12) was positioned on the high-temperature side of the end section of the line, and it was confirmed that it is a heat transfer device with a large heat transfer capacity suitable for heat transfer.

[0123] The white triangle in the drawing represents the thermal efficiency measured in an experimental heat transfer device of the same size as the one used in the numerical calculation, and the white square in the drawing represents the resulting heat transfer rate measured in the experimental heat transfer device. Consequently, it was confirmed that the numerical calculation result closely approximates the experimental result. Third configuration (arrangement of the device)

[0124] With reference to the Fig. 13 to Fig. Paragraph 19 describes a third embodiment of the disclosure, i.e., an industrial furnace equipped with the heat transfer device according to the first embodiment. The components that do not differ from those of the first embodiment are assigned the same reference numerals, without these components being described.

[0125] As in Fig. As shown in Figure 13, an oven 100 comprises a rectangular oven wall 102 with insulation, a worktable 104 onto which a workpiece W is placed (see Fig. 16), which is processed in the interior bounded by the furnace wall 102 (hereinafter referred to as "the interior of the furnace"), heating devices 106 which regulate the temperature inside the furnace (heat it to a predetermined temperature), the heat transfer device 10 (see Fig. 15 and Fig. 16) and reflector units 108.

[0126] As regards the heating devices 106, two are arranged parallel between opposite sides of the furnace wall 102 on the top of the work table 104 and two are arranged parallel between opposite sides of the furnace wall 102 on the underside of the work table 104.

[0127] As in Fig. As shown in Figure 14, the reflector units 108 each have a tube section 112 in the form of a hollow cylinder in which an opening section 110 is formed, extending axially through the tube section 112, and a reflector 114, which is arranged at the distal end of the tube section 112 and in which a reflecting surface 114A with a paraboloid is formed (see Figure 14). Fig. 15).

[0128] As in Fig. As shown in Figure 15, the reflector 114 is mounted at a predetermined angle with respect to the axial direction of the pipe section 112. Furthermore, one end of the opening section 110 of the pipe section 112 is open towards the reflector 114 (see Figure 15). Fig. 13).

[0129] The reflector unit 108, configured in this way, is arranged in the furnace 100 such that the pipe section 112 extends through the upper or lower furnace wall 102 and the reflector 114, attached to one end of the pipe section 112, is positioned inside the furnace. The other end of the pipe section 112 is located outside the furnace wall 102 (hereinafter referred to as "the exterior / outside the furnace").

[0130] The reflector unit 108 is configured such that when the other end of the pipe section 112 is rotated, the reflector 114 can be rotated about the axis of the pipe section 112. Furthermore, the reflector unit 108 is configured such that the reflector 114 can be moved towards and away from the furnace wall 102 when the pipe section 112 is moved forward and backward relative to the furnace wall 102.

[0131] As in Fig. As shown in Figure 15, the heat transfer device 10 is also arranged in the opening section 110 of the tube section 112 of the reflector unit 108. The side of the first end section 12A of the heat transfer device 10 is inserted into the interior of the furnace 100 (the furnace wall 102), and the side of the second end section 12B projects out of the furnace 100 (the furnace wall 102). That is, in the axial direction of the heat transfer device 10 (the tubular body 12), the section from the first end section 12A to the first heat exchanger 14 is inserted into the interior of the furnace, and the section from the second heat exchanger 16 to the second end section 12B is arranged outside the furnace. In addition, the regenerator 18 of the heat transfer device 10 is arranged in the furnace wall 102 of the furnace 100. Fig. 15 is the thickness of the furnace wall 102, shown thinly for a simple description in the drawing.

[0132] Furthermore, the heat transfer device 10 is attached to the furnace wall 102. As in Fig. 15 and Fig. As shown in Figure 16, the heat transfer device 10 can thus be received by the opening section 110 when the reflector unit 108 (the tube section 112) is moved forward inside the furnace. When the reflector unit 108 (the tube section 112) is moved backward out of the furnace, the side of the first end section 12A of the heat transfer device 10 on the side of the reflective surface 114A of the reflector 114 can protrude from the opening section 110 of the reflector unit 108, so that it is exposed to the interior of the furnace.

[0133] As in Fig. As shown in Figure 15, the section of the tubular body 12 of the heat transfer device 10 from the first end section 12A to the first heat exchanger 14 along the axial direction is designed as a thick plate section 12C, the plate thickness of which is thicker than that of the other section; the other section is called thin plate section 12D.

[0134] As in Fig. As shown in Figure 13, the reflector unit 108 and the heat transfer device 10 arranged in this way are arranged as a set (2 each) at a fixed distance from each other in two rows in the furnace wall 102 at the top of the furnace 100, and as a set (2 each) at a fixed distance from each other in two rows in the furnace wall 102 at the bottom of the furnace 100. That is, when the furnace 100 is viewed from above, the reflector units 108 and the heat transfer devices 10 are arranged on the outer sides of the heating devices 106. (Operation)

[0135] The following describes the operation of oven 100. First, a case in which oven 100 is heated is described.

[0136] As in Fig. 13, Fig. 15 and Fig. As shown in Figure 16, the pipe sections 112 of the reflector units 108 have in this case been moved forward inside the furnace in order to move the reflectors 114 away from the furnace wall 102.

[0137] Consequently, the heat transfer devices 10, as in Fig. Figure 15 shows that the heat transfer devices 10 are completely enclosed within the opening sections 110 of the pipe sections 112. That is, the side of the first end section 12A of the heat transfer devices 10 is not located inside the furnace (the sides of the reflective surface 114A of the reflectors 114). Furthermore, the end sections of the inner pipes 22 of the heat transfer devices 10 are closed by the control valves 20 (see Figure 15). Fig. 3).

[0138] As in Fig. As shown in Figure 16, the pipe sections 112 of the reflector units 108 are rotated about their axes so that the reflecting surfaces 114A of the reflectors 114 point in the direction of the adjacent heating devices 106 and the worktable 104 (of the workpiece W).

[0139] In this state, the workpiece W, which is the processing target, is placed on the worktable 104 inside the oven and the heating devices 106 are switched on, thereby heating the temperature inside the oven to the predetermined temperature.

[0140] As in Fig. As shown in Figure 16, even when the heating devices 106 are switched on and the temperature difference between the inside and outside of the furnace increases, the self-excited thermoacoustic vibrations are not generated in the regenerators 18 at that time, because the end sections of the inner tubes 22 of the heat transfer devices 10 are closed by the control valves 20. That is, a situation is prevented in which standing waves generated by the self-excited thermoacoustic vibrations occur in the pipes of the heat transfer devices 10 and heat is released from the inside of the furnace to the outside.

[0141] Furthermore, since the heat transfer devices 10 are completely housed within the opening sections 110 of the pipe sections 112, it is prevented that the radiation inside the furnace directly impacts the heat transfer devices 10 or after it has been reflected by the reflective surfaces 114A of the reflectors 114.

[0142] That is, by preventing the radiation inside the oven from striking the heat transfer devices 10, it is also prevented that the heat inside the oven is conducted outwards by thermal conduction via the tubular bodies 12 of the heat transfer devices 10 extending from the inside of the oven to the outside.

[0143] Because the heat inside the oven is prevented from being dissipated to the outside via the heat transfer devices 10, the temperature inside the oven 100 can be efficiently heated to the predetermined temperature.

[0144] As in Fig. 15 and Fig. As shown in Figure 16, the reflective surfaces 114A of the reflectors 114 also point in the direction of the adjacent heating devices 106 and the worktable 104. As a result, the radiation from the heating devices 106 is reflected by the reflective surfaces 114A of the reflectors 114 and strikes the workpiece W placed on the worktable 104. Consequently, the workpiece W placed on the worktable 104 is heated efficiently.

[0145] The following describes a case in which the oven is cooled to 100°C.

[0146] Once the heating of the workpiece W is complete, after the temperature inside the furnace has reached the predetermined temperature, the heating devices 106 are switched off first. Then, the control valves 20 of the heat transfer devices 10 are moved backward to open the end sections of the inner tubes 22.

[0147] As in Fig. 17 to Fig. As shown in Figure 19, the pipe sections 112 of the reflector units 108 are then moved backwards out of the furnace in order to move the reflectors 114 towards the furnace wall 102. As shown in Fig. As shown in Figure 18, the side of the first end section 12A (the side inside the furnace) of the heat transfer device 10, which is attached to the furnace wall 102, is thereby exposed to the opening sections 110 of the pipe sections 112 from inside the furnace (the sides of the reflective surface 114A of the reflectors 114). That is, the side of the first end section 12A of the heat transfer devices 10 is positioned at the positions of the focal points of the reflectors 114 (the reflective surfaces 114A).

[0148] As in Fig. In addition, as shown in Figure 19, the pipe sections 112 of the reflector units 108 are rotated so that the reflecting surfaces 114A of the reflectors 114 (see Figure 19) are rotated so that the reflecting surfaces 114A of the reflectors 114 are rotated. Fig. 18) in the direction of the workpiece W and the furnace wall 102. Consequently, the infrared radiation, as shown in Fig. 18 shown, (see the dashed lines in Fig. 18) from the furnace wall 102 and the workpiece W, which have reached a high temperature, is reflected by the reflective surfaces 114A of the reflectors 114 and strikes (in a focused manner) the side of the first end section 12A of the heat transfer devices 10, which project from the opening sections 110 into the reflectors 114. Consequently, the tubular bodies 12 near the striking positions of the heat transfer devices 10 are heated. The sections of the metallic tubular bodies 12 from the side of the first end section 12A to the first heat exchangers 14 are designed as thick plate sections 12C, whose plate thickness is locally greater compared to the other sections (the thin plate sections 12D), so that the heat can be efficiently conducted from the positions where the radiation strikes to the positions where the first heat exchangers 14 are located.

[0149] When the first heat exchangers 14 are heated by radiation incident on the side of the first end section 12A of the heat transfer devices 10 inside the furnace, the temperature ratio between the two end sections (the side of the first heat exchanger 14 and the side of the second heat exchanger 16) of the regenerators 18 exceeds the threshold. This generates self-excited thermoacoustic vibrations in the regenerators 18 and standing waves in the pipes of the heat transfer devices 10, where the end sections of the inner tubes 22 have been actuated by the control valves 20. The regenerators 18 are located in the pipes at positions 25% of the pipe length from the closed surfaces 26, ensuring efficient heat transfer from the first heat exchangers 14 inside the furnace to the second heat exchangers 16 outside the furnace.

[0150] As in Fig. As shown in Figure 19, at this time the reflectors 114 of the reflector units 108 rotate about the axes of the pipe sections 112. This allows the radiation to be reflected from a wide area, encompassing the workpiece W and the furnace wall 102, and to strike the heat transfer devices 10, so that the interior of the furnace is cooled uniformly.

[0151] In this way, the standing waves generated by the self-excited thermoacoustic vibrations in the heat transfer devices 10 are used in the furnace 100 to transfer the heat inside the furnace to the outside, thus it is not necessary to use a pump or actuator for heat dissipation, consequently the design of the device is simple and the heat can be dissipated efficiently.

[0152] During the cooling of the furnace, the radiation inside the furnace (from the furnace wall 102 and the workpiece W) is reflected by the reflectors 114, focused, and strikes the side of the first end section 12A of the heat transfer devices 10, which are arranged at the positions of the focal points of the reflectors 114, so that the heat transfer devices 10 can be heated efficiently. That is, the heat inside the furnace is efficiently transported to the heat transfer devices 10.

[0153] In the heat transfer devices 10, the sections of the tubular bodies 12 from the positions where the radiation hits the side of the first end section 12A, up to the first heat exchangers 14, are designed as thick plate sections 12C, the plate thickness of which is locally greater compared to the other sections (the thin plate sections 12D), so that the heat can be efficiently conducted from the positions where the radiation hits the tubular bodies 12, up to the first heat exchangers 14.

[0154] With the Oven 100, the heat inside the oven can therefore be released to the outside even more efficiently.

[0155] Although the positions of the foci of the reflectors 114 in the present embodiment correspond to positions on the side of the first end section 12A of the first heat exchangers 14 of the heat transfer devices 10, it is not necessary to conduct the heat along the axial direction of the tubular bodies 12 when the positions of the foci of the reflectors 114 are moved to the positions of the first heat exchanger 14 of the heat transfer devices 10, thereby making the thick plate sections 12C unnecessary and allowing the heat to be transported even more efficiently from the interior of the furnace via the heat transfer devices 10.

[0156] In the present embodiment, the reflective surfaces 114A of the reflectors 114 point towards the heating devices 106 and the worktable 104 when the oven 100 is heated. As in Fig. 20 and Fig. As shown in Figure 21, the pipe sections 112 of the reflector units 108 can also be rotated about their axes so that the back sides 114B of the reflectors 114 point in the direction of the adjacent heating devices 106.

[0157] As in Fig. 20 and Fig. As shown in Figure 21, in this case, the radiation from the adjacent heating devices 106 is prevented from reaching the heat transfer devices 10, since the rear surfaces 114B of the reflectors 114 point towards the adjacent heating devices 106. Because the heat transfer devices 10 are completely enclosed within the opening sections 110 of the tube sections 112, the radiation inside the furnace is prevented from reaching the heat transfer devices 10, even if it is reflected by the reflective surfaces 114A of the reflectors 114. Consequently, the radiation reaching the heat transfer devices 10 is further limited, and the transfer of heat from the interior of the furnace to the outside via the tubular bodies 12 of the heat transfer devices 10 is further prevented.

[0158] If the reflector units 108 are operated in this way, the oven 100 can be heated efficiently. Fourth configuration (arrangement of the device)

[0159] As a fourth form of the revelation, with reference to the Fig. 22 and the Fig. 23 describes an industrial furnace equipped with the heat transfer device 10 according to the first embodiment. The same reference numerals are assigned to the components that do not differ from those of the third embodiment, without describing these components. It should be noted that only the shape of the reflectors differs from the third embodiment; therefore, only this aspect is described.

[0160] As in Fig. 22 and Fig. Figure 23 shows that a reflector 202 used in the reflector unit 108 of an oven 200 has a radially asymmetric cross-section on both sides and is a defocused reflector. The side of the reflector 202 that is more axially directed upwards in the radial cross-section is a strongly curved section 204, and the opposite side is a weakly curved section 206.

[0161] The reflector 202 of the reflector unit 108 is rotated about its axis by turning the pipe section 112, but it does not move forwards and backwards in the axial direction. The heat transfer device 10 can be moved forwards and backwards along its axial direction in the opening section 110 of the pipe section 112.

[0162] Moreover, the heat transfer device 10 is not equipped with a control valve according to the present design. (Operation)

[0163] In the oven 200 constructed in this way, the heat transfer device 10 - as in Fig. Figure 22 shows that the heat transfer device 10 is moved backwards out of the oven during heating. This means that the part of the heat transfer device 10 up to the position of the first heat exchanger 14 is located outside the oven, and only the side of the first end section 12A is exposed to one side of the reflective surface 202A of the reflector 202.

[0164] Even though a temperature difference occurs between the inside and outside of the furnace due to heating by the heating device 106, the temperature ratio between the two end sections of the regenerator 18 in furnace 200 does not exceed the threshold value. Therefore, self-excited thermoacoustic oscillations are not generated in the regenerator 18 because the first heat exchanger 14, the second heat exchanger 16, and the regenerator 18 of the heat transfer device 10 are all located outside the furnace. That is, the heat transfer device 10 prevents a situation in which heat inside the furnace is transported to the outside by the standing wave generated by the self-excited thermoacoustic oscillations.

[0165] Moreover, the strongly curved section 204 of the reflector 202 points in the direction of the heating device 106, thus the radiation from the adjacent heating device 106 is blocked by the strongly curved section 204 and cannot reach the heat transfer device 10.

[0166] Accordingly, when heating the oven, a situation is prevented in which the side of the first end section 12A of the tubular body 12 of the heat transfer device 10 is heated by the radiation of the heating device 106 and the heat inside the oven is transported to the outside by thermal conduction via the tubular body 12.

[0167] During the cooling of the furnace 200, the heating device 106 is switched off. Subsequently, the heat transfer device 10 is moved forward inside the furnace. As in Fig. As shown in Figure 23, the section of the heat transfer device 10 from the first end section 12A to the first heat exchanger 14 is therefore arranged inside the furnace, the regenerator 18 is arranged in the furnace wall 102, and the section of the heat transfer device 10 from the second heat exchanger 16 to the second end section 12B is arranged outside the furnace.

[0168] The reflector 202 then points towards the workpiece W and the furnace wall 102, so that the radiation emitted by the workpiece W and the furnace wall 102 and the radiation reflected by the reflecting surface 202A of the reflector 202 (see the dashed lines in Fig. 23) strikes the side of the first end section 12A of the heat transfer device 10. The positions where the radiation strikes the tubular body 12 of the heat transfer device 10 are heated, and the heat is conducted via the thick plate section 22C to the first heat exchanger 14. This efficiently heats the first heat exchanger 14. Consequently, the temperature ratio between the two end sections of the regenerator 18 exceeds the threshold, so that self-excited thermoacoustic vibrations are generated in the regenerator 18 and a standing wave is generated in the duct of the heat transfer device 10. Thus, the heat inside the furnace can be efficiently dissipated to the outside. That is, the furnace 200 can be efficiently cooled.

[0169] In furnace 200, the section of the heat transfer device 10 up to the first heat exchanger 14 is located outside the furnace during heating. This prevents the temperature difference between the inside and outside of furnace 200 from generating self-excited thermoacoustic vibrations in the regenerator 18 of the heat transfer device 10; consequently, it prevents heat from being released from the furnace. That is, even in a design where the heat transfer device 10 is not equipped with the control valve 20, heat release through the heat transfer device 10 can be prevented during heating of furnace 200.

[0170] In the oven 200, during heating, a rear side 202B of the strongly curved section 204 of the reflector 202 of the reflector unit 108 points towards the adjacent heating device 106, so that the radiation of the heating device 106 can be prevented from hitting the heat transfer device 10, which in turn prevents heat from being released (heat transported) to the outside by the heat transfer device 10 due to heat conduction.

[0171] During the cooling of the furnace 200, the heat transfer device 10 inside the furnace is moved forward, so that the first heat exchanger 14 is located inside the furnace and the second heat exchanger 16 is located outside the furnace, whereby, according to the temperature ratio between the inside and the outside of the furnace 200, the self-excited thermoacoustic vibrations are generated in the regenerator 18 of the heat transfer device 10 and the standing wave is generated in the duct of the heat transfer device 10; consequently, the heat inside the furnace can be efficiently transferred to the outside.

[0172] Although the defocused reflector 202 is used in the reflector unit 108 of the furnace 200, the heat can be efficiently transported from the interior of the furnace to the heat transfer device 10 by means of the radiation reflected by the defocused reflector striking the heat transfer device 10.

[0173] Although, according to the present embodiment, the radiation from the heating device 106 is prevented from striking the heat transfer device 10 by having the rear side 202B of the strongly curved section 204 of the reflector 202 point towards the adjacent heating device 106 when the oven 200 is heated, the reflective surface 202A of the reflector 202 – as in the third embodiment – ​​can also point towards the heating device 106 and the worktable 104 (the workpiece W), so that the radiation from the heating device 106 is reflected by the reflective surface 202A of the reflector 202 and strikes the workpiece W. In this case, the efficiency with which the workpiece W is heated when the oven 200 is heated is increased.

[0174] The following describes another example of the oven 200. The only difference here is the heat transfer device 10, so only this is described. As in Fig. Figure 24 shows a heat transfer device 10 in which a radiation-transmitting section 210 consisting of a radiation-transmitting material, such as glass, is formed only on the metal section of the tubular body 12, which is arranged on the outer circumferential side of the first heat exchanger 14.

[0175] The first heat exchanger 14 has the form of a ring 212, which is made of metal and is mounted between the inner tube 22 and the outer tube 24 of the heat transfer device 10, and in which numerous opening sections 214 extending in the axial direction are formed.

[0176] When the heat transfer device 10 is designed in this way, during the cooling of the furnace 200, the radiation inside the furnace or the radiation reflected by the reflector 202 is guided through the radiation-transparent section 210 and directly impinges on the first heat exchanger 14. Consequently, the first heat exchanger 14 (the ring 212) is heated directly by the radiation, so that heat inside the furnace is transported even more efficiently to the first heat exchanger 14. Fifth design

[0177] As a fifth form of the revelation, with reference to the Fig. References 25 to 28 describe an industrial furnace equipped with the heat transfer device 10 according to the first embodiment. The same reference numerals are assigned to the components that do not differ from those of the third embodiment, without describing these components further. It should be noted that only the shape of the reflectors and the arrangement of the heating devices differ from the third embodiment, so only this aspect is described. (Arrangement of the device)

[0178] As in Fig. As shown in Figure 25, the reflectors 302, which represent the reflector units 108 of an oven 300, each have a parabolic section 304, which is similar to the reflector 114, which comprises a paraboloid according to the third embodiment, as well as a semicircular trough section 306, which extends continuously downwards from the lower end section of the parabolic section 304, and a semicircular conical section 308, which extends continuously from the lower end section of the trough section 306.

[0179] The heat transfer devices 10 are arranged in the opening sections 110 of the pipe sections 112 of the reflector units 108. As shown in Fig. As shown in Figure 26, each heat transfer device 10, as in the third embodiment, is attached to the furnace wall 102, wherein the section from the first end section 12A to the first heat exchanger 14 is arranged inside the furnace, the regenerator 18 is arranged in the furnace wall 102 and the section from the second heat exchanger 16 to the second end section 12B is arranged outside the furnace.

[0180] The tube sections 112 of the reflector units 108 can be rotated about their axes, and the reflectors 302 can be rotated together with the tube sections 112. However, the reflector units 108 do not move forward and backward relative to the furnace wall 102.

[0181] In addition, the furnace 300 has two heating devices 106 on one side, which extend horizontally from the furnace wall 102 on opposite sides under the work table 104, with a total of four heating devices and reflector units being provided on one side in two parallel rows (in plan view) on the top side, comprising two heating devices 106A and two reflector units 108 (heat transfer devices 10), which extend downwards from the furnace wall 102. (Operation)

[0182] The following describes the operation of the furnace 300 constructed in this manner. First, the heating of the furnace 300 is described.

[0183] When the furnace 300 is heated, the end sections of the inner tubes 22 are closed by the control valves 20 of the heat transfer devices 10 (see Fig. 3) The pipe sections 112 are then rotated about their axes so that the rear sides 302B of the trough sections 306 and the conical sections 308 of the reflectors 302 point in the direction of the adjacent heating devices 106A.

[0184] In this state, the workpiece W is placed on the worktable 104 and positioned inside the furnace, with the heating devices 106, 106A being switched on.

[0185] At this point, even when the heating devices 106, 106A in the furnace 300 are switched on and the temperature difference between the inside and outside of the furnace increases, the self-excited thermoacoustic vibrations are not generated in the regenerators 18 of the heat transfer devices 10, because the end sections of the inner tubes 22 are closed by the control valves 20. That is, a situation is prevented in which standing waves generated by the self-excited thermoacoustic vibrations occur in the pipes of the heat transfer devices 10 and heat is released from the inside of the furnace to the outside.

[0186] Furthermore, the heating devices 106A are arranged parallel to the adjacent heat transfer devices 10. However, when the furnace 300 is heated, the heat transfer devices 10 are blocked by the rear faces 302B of the trough sections 306 and the conical sections 308 of the reflectors 302, thus preventing the radiation from the heating devices 106A from striking the heat transfer devices 10 directly or after being reflected by the reflectors 302.

[0187] Consequently, the heat inside the oven can be prevented from being lost to the outside via heat conduction through the tubular bodies 12 of the heat transfer devices 10. That is, the efficiency with which the oven 300 is heated is increased.

[0188] The following describes the operation when the oven is cooled to 300°C.

[0189] First, the heating devices 106, 106A of the furnace 300 are switched off. Then, the tube sections 112 of the reflector units 108 are switched off, as shown in Fig. 27 shown, rotated so that the reflective surfaces 302A of the reflectors 302 point towards the workpiece W and the furnace wall 102.

[0190] In addition, the control valves 20 of the heat transfer devices 10 are moved, thereby opening the end sections of the inner tubes 22.

[0191] In this state, the radiation from the workpiece W and the furnace wall 102 is reflected by the trough sections 306 and the conical sections 308 of the reflectors 302 and strikes the side of the first end section 12A of the first heat exchangers 14 of the heat transfer devices 10, heating these areas. The sections of the tubular bodies 12 of the heat transfer devices 10 on the side of the first end section 12A of the first heat exchangers 14 are designed as thick plate sections 12C (see Fig. 15), so that heat can be conducted more easily through these than through the thin plate sections 12D (see Fig. 15). Therefore, the heat on the side of the first end section 12A of the first heat exchangers 14 of the heat transfer devices 10 can be efficiently transported to the first heat exchangers 14.

[0192] Furthermore, the radiation from the workpiece W and the furnace wall 102 strikes the parabolic sections 304 of the reflectors 302 directly, as does the radiation reflected from the trough sections 306 and the conical sections 308, which is reflected to the positions where the first heat exchangers 14 of the heat transfer devices 10 are located. That is, the radiation from the workpiece W and the furnace wall 102 is focused and strikes the first heat exchangers of the heat transfer devices 10, so that the first heat exchangers 14 are heated efficiently.

[0193] That is, the heat inside the oven is efficiently transported to the first heat exchangers 14.

[0194] Furthermore, if the temperature ratio between the two end sections (the end sections on the side of the first heat exchangers 14 and the end sections on the side of the second heat exchangers 16) of the regenerators 18 exceeds the threshold value, the self-excited thermoacoustic vibrations are generated in the regenerators 18 of the heat transfer devices 10 and the standing waves are generated in the lines of the heat transfer devices 10, so that the heat inside the furnace is efficiently transferred to the outside by the standing waves.

[0195] In oven 300, the back sides 302B of the reflectors 302 point towards the heating devices 106A during heating of the oven, thus preventing the radiation from the heating devices 106, 106A from striking the heat transfer devices 10, which in turn prevents heat from being released to the outside via the heat transfer devices 10 due to thermal conduction. That is, the heating power is increased.

[0196] Since the heating devices 106A extend upwards and downwards in the oven 300, the workpiece W placed at a certain height on the worktable 104 can be heated efficiently.

[0197] In furnace 300, the semicircular cross-section trough sections 306 and the conical sections 308 are arranged continuously with the undersides of the parabolic sections 304 of the reflectors 302, so that the radiation is reflected and focused by the furnace wall 102 and the workpiece W and strikes the heat transfer devices 10. By utilizing the radiation, the heat inside the furnace is therefore conducted even more efficiently to the heat transfer devices 10.

[0198] The heat inside the furnace 300 is efficiently conducted by radiation to the first heat exchangers 14 of the heat transfer devices 10, so that it is transported from the first heat exchangers 14 to the second heat exchangers 16 via the self-excited thermoacoustic vibrations in the heat transfer devices 10. That is, the heat inside the furnace 300 can be efficiently released to the outside.

[0199] As in Fig. As shown in Figure 28, by making the heat transfer devices 10 movable forwards and backwards with respect to the furnace wall 102 and being able to move up to the first heat exchangers 14 in the furnace wall 102 when the furnace 300 is heated, it is possible to prevent the first heat exchangers 14 from being heated, which in turn prevents the self-excited thermoacoustic vibrations from being generated in the regenerators 18.

[0200] Furthermore, when the furnace 300 is heated, the reflective surfaces 302A of the reflectors 302 can point in the direction of the adjacent heating devices 106A and the workpiece W, so that the radiation from the heating devices 106A is reflected by the reflective surfaces 302A and hits the workpiece W, thereby increasing the efficiency with which the workpiece W is heated. Miscellaneous (heat transfer device)

[0201] The heat transfer devices according to the first and second embodiments have been described above, but the disclosure is not limited to them.

[0202] In the heat transfer device 50 according to the second embodiment, for example, the control valve 20 is arranged on the side of the second end section 12B of the tubular body 12; however, the heat transfer device 50 can also have an arrangement in which the valve body is inserted from the radially outer side at a position that is the same distance as the axial distance from the center of the regenerator 18 to the first end section 12A of the tubular body 12, specifically on the side of the second end section 12B of the tubular body 12 from the center of the regenerator 18 in the axial direction. In this case, the center of the regenerator 18 is located at the position of a node of the standing wave in the axial direction, so that the heat transfer can be interrupted when the valve body is inserted.

[0203] Furthermore, the center of the regenerator 18 was arranged in the axial direction at a position that is 25% of the line length L0 relative to the end section on the high-temperature side (the closed surface 26 of the heat transfer device 10, the first end section 12A of the heat transfer device 50). However, if the center of the regenerator 18 is arranged in the axial direction in a range of 12.5% ​​to 25%, the heat transfer rate is sufficient for the device to be used as a heat transfer device.

[0204] Although the heat transfer devices 10 and 50 of the first and second embodiments are equipped with the control valve 20 as a control device, the heat transfer devices do not necessarily have to be equipped with the control valve. For example, if it is not necessary to interrupt the heat transfer, such as in a case where the heat is always obtained from waste heat, it is conceivable that the heat transfer device is not equipped with the control valve.

[0205] Furthermore, it is conceivable to equip the heat transfer device with a power generator, for example, a loudspeaker generator, which is attached to the second end section 12B of the heat transfer device 50 arranged on the furnace 40, instead of the control valve 20. The loudspeaker is set into vibration by a standing wave corresponding to the self-excited thermoacoustic wave, and electricity is generated. In this case, it is possible to interrupt the heat transfer if the control valve, as described above, is inserted from the radially outer side inside the tubular body 12. (Oven)

[0206] Furnaces 100, 200 and 300 were described according to the third to fifth configurations, but the revelation is not limited to these.

[0207] According to the third embodiment, the reflector 114 corresponds to a Newtonian paraboloid, with the heat transfer device 10 being arranged at the position of the focus; however, it is also possible to use a Cassegrain type, Gregorian or Martin type, which also use a reflector as a focus on the heat transfer device 10.

[0208] In the third embodiment, the reflector unit 108 moves forwards and backwards in relation to the furnace 100, and in the fourth embodiment, the heat transfer device 10 moves forwards and backwards in relation to the furnace 200 and the furnace 300; however, both devices can also be arranged to move forwards and backwards.

[0209] According to the third embodiment, the reflector 114 is mounted at an angle to the axial direction of the pipe section 112; however, the reflector 114 can also be mounted in such a way that its angle of inclination can be changed. In this case, if the reflector 114 is rotated while its angle of inclination is changed, the radiation from the furnace wall 102 and the workpiece W can strike the heat transfer device 10 over an even wider area. Consequently, the furnace can be cooled even more efficiently.

[0210] In the third and fifth embodiments, the control valve 20 has a configuration in which it closes the end section of the inner tube 22, so that the self-excited thermoacoustic vibrations are not generated in the regenerator 18 when the furnace is heated; in the fourth embodiment, however, the heat transfer device 10 can also have a configuration in which the self-excited thermoacoustic vibrations are not generated by ensuring that the temperature ratio between the two end sections (the end section on the side of the first heat exchanger 14 and the end section on the side of the second heat exchanger 16) of the regenerator 18 does not exceed the threshold value by moving the heat transfer device 10 rearward out of the furnace. In this case, the heat transfer device 10 does not require the control valve 20.

[0211] In the third to fifth embodiments, the case in which a predetermined oven temperature (within a predetermined temperature range) is maintained was not described, but in principle, the oven is heated by the heating devices so that an amount of heat is supplied that corresponds to the amount of heat naturally released from the oven. Depending on the type of oven, however, it is also conceivable that the heat is released by the standing wave according to the self-excited thermoacoustic oscillations in the heat transfer device 10, the heat transfer rate of which was regulated by the control valve 20 when the oven was heated by the heating device.

[0212] In the third to fifth embodiments, the heat transfer device 10 was arranged in the opening section 110 of the pipe section 112 of the reflector unit; however, the heat transfer device 10 can also be arranged at a position that does not correspond to the pipe section 112 in the furnace. In this case, the radiation reflected by the reflecting surface of the reflector strikes the other position where the heat transfer device 10 is located.

[0213] In the third to fifth embodiments, cases were described with regard to the focusing of the radiation incident on the heat transfer device 10 in which the reflectors have a focus, such as a paraboloid, but the reflecting surface of the reflector does not have to have a focus.

[0214] Moreover, it is also possible to use the thick plate section 12C of the heat transfer device 10 and the radiation-transmitting section 210 in a furnace that is not equipped with a reflector, and to apply the configuration in which the heat transfer device 10 is movable forwards and backwards with respect to the furnace wall.

[0215] In addition, in the third to fifth embodiments the heat transfer device 10 according to the first embodiment was used, but the heat transfer device 50 according to the second embodiment can also be used.

[0216] The disclosure of the Japanese patent application JP 2017-10379 A is incorporated in full into this patent specification by reference.

[0217] All documents, patent applications and technical standards cited in this patent specification are incorporated into the present patent specification by reference to the same extent as if each individual cited document, patent specification or technical standard were individually incorporated herein by reference.

Claims

[1] Heat transfer device (10, 50), comprising: a housing extending over a high-temperature heat source (28) and a low-temperature heat bath (30) which has a lower temperature than the high-temperature heat source (28); comprising a closed space in which non-condensing gas is enclosed, wherein a conduit (X) is formed in the housing and both end sections of the conduit (X) are sealed; a regenerator (18) which is arranged in the conduit (X) and provided with pores (34) which connect the two end sections of the regenerator (18) together and which is insulated from the outside of the casing; a first heat exchanger (14) which is arranged next to the end section of the regenerator (18) on the high-temperature heat source side in the conduit (X) and which allows the heat from the high-temperature heat source (28) to be directed towards the regenerator (18); and a second heat exchanger (16) which is arranged next to the end section of the regenerator (18) on the low-temperature heat bath side in the line (X) and which allows the heat from the regenerator (18) to be directed towards the low-temperature heat bath (30), wherein the center of the regenerator (18) is arranged along the extension direction of the line (X) at a position in the line (X) which is between 12.5% ​​and 25% of the line length from the end section of the line (X) on the high-temperature heat source side. [2] Heat transfer device (10, 50) according to claim 1, wherein the line (X) comprises: an inner tube (22), part of which connects the high-temperature heat source side with the low-temperature heat bath side in the housing, and an outer tube (24) formed on the outside of the inner tube (22) and connected to the inner tube (22) on the low-temperature heat bath side, wherein an end section on the high-temperature heat source side of the outer tube (24) is closed, wherein the first heat exchanger (14), the second heat exchanger (16) and the regenerator (18) are arranged in the outer tube (24). [3] Heat transfer device (10, 50) according to claim 1 or 2, wherein the heat transfer device (10, 50) comprises a control unit which is arranged in the end section of the housing on the low-temperature heat bath side and is movable forwards and backwards inside the housing and which converts the waveform of a standing wave generated in the line (X) by a self-excited thermoacoustic wave by moving forwards. [4] Oven (40, 100, 200, 300), comprising: a furnace wall consisting of insulation (102); a heating device arranged inside the furnace (40, 100, 200, 300) bounded by the furnace wall (102) and which heats the interior of the furnace (40, 100, 200, 300); and the heat transfer device (10, 50) according to one of claims 1 to 3, wherein the regenerator (18) is arranged on the furnace wall (102), the first heat exchanger (14) is arranged inside the furnace (40, 100, 200, 300) and the second heat exchanger (16) is arranged outside the furnace (40, 100, 200, 300), at least when cooling the furnace (40, 100, 200, 300). [5] Oven (40, 100, 200, 300) according to claim 4, further comprising a reflector (114, 202, 302) which reflects the radiation inside the oven (40, 100, 200, 300) so that the radiation strikes the heat transfer device (10, 50) arranged inside the oven (40, 100, 200, 300). [6] Oven (40, 100, 200, 300) according to claim 5, further comprising a wave body (38) which supports the reflector (114, 202, 302) inside the oven (40, 100, 200, 300) and extends outwards from the inside of the oven (40, 100, 200, 300). [7] Oven (40, 100, 200, 300) according to claim 6, wherein the reflector (114, 202, 302) is integrally formed with the shaft body (38) and rotatable about the axial direction of the shaft body (38). [8] Oven (40, 100, 200, 300) according to claim 6 or 7, wherein an opening section is formed in the shaft body (38) which extends in the axial direction of the shaft body (38), wherein the heat transfer device (10, 50) is housed in the opening section and the end section of the heat transfer device (10, 50) is exposed on the side on which the first heat exchanger (14) is arranged, at least during the cooling of the oven (40, 100, 200, 300), from the interior of the opening section to one side of the reflective surface of the reflector (114, 202, 302). [9] Oven (40, 100, 200, 300) according to claim 8, wherein a part of the end section of the heat transfer device (10, 50) on the side on which the first heat exchanger (14) is arranged is positioned in a focus of the reflective surface of the reflector (114, 202, 302) at least during the cooling of the oven (40, 100, 200, 300). [10] Oven (40, 100, 200, 300) according to claim 8 or 9, wherein the reflector (114, 202, 302) is integrally movable forwards and backwards with respect to the oven wall (102) along the axial direction with the shaft body (38). [11] Oven (40, 100, 200, 300) according to any one of claims 4 to 10, wherein the heat transfer device (10, 50) is movable forwards and backwards with respect to the oven wall (102) along the axial direction of the heat transfer device (10, 50). [12] Oven (40, 100, 200, 300) according to any one of claims 4 to 11, wherein the plate thickness of the casing, from the position where the radiation hits the interior of the oven (40, 100, 200, 300) to the position where the first heat exchanger (14) is arranged, is locally greater than the plate thickness of the other casing section. [13] Oven (40, 100, 200, 300) according to one of claims 4 to 12, wherein the section of the housing on the outer circumferential side of the first heat exchanger (14) is formed by a radiation-transmitting element.

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