Geothermal power generation equipment

Abstract

The present invention comprises a heat transfer body 2, a first heat exchange unit 3 for heat exchange between the heat transfer body and an underground area X provided to one end 2a side of the heat transfer body, and a second heat exchange unit 4 for heat exchange between the heat transfer body and outside air Z provided to the other end side of the heat transfer body. The first heat exchange unit comprises: a thermally conductive first square tube body surrounding the outer peripheral surface on one end side of the heat transfer body; a heat transfer / coupling structure that is disposed between the heat transfer body and the first square tube body, and couples the first square tube body to the heat transfer body in a manner where thermal conduction is possible; a thermally conductive second square tube body 7 surrounding the outside of the first square tube body; a thermoelectric conversion module that is disposed between the first and second square tube bodies, and that thermally contacts the first square tube body at one surface thereof, and thermally contacts the second square tube body at the other surface thereof; a first heat insulating member 10 that seals an opening positioned on one end side of the heat transfer body in the first and second square tube bodies; and a second heat insulating member 11 that seals an opening positioned on the other end side of the heat transfer body in the first and second square tube bodies in a state going through the heat transfer body.

Description

[Technical field]

[0001] The present invention relates to a geothermal power generation device that utilizes the temperature difference between the ground and the earth's surface layer or the outside air, or the temperature difference between the earth's surface layer and the outside air, to generate power through a thermoelectric conversion module. [Background technology]

[0002] In recent years, solving the problem of global warming caused by the increase in greenhouse gases has become a global issue, and from the perspective of preventing the generation of greenhouse gases, there has been a worldwide push to use natural energy sources such as solar, wind, hydroelectric and geothermal energy instead of fossil fuels.

[0003] For example, known power generation methods utilizing natural energy include solar power generation, wind power generation, hydroelectric power generation, geothermal power generation, and biomass power generation.

[0004] Of these, geothermal power generation is a power generation method that utilizes geothermal energy. In conventional geothermal power generation, wells are drilled to a geothermal reservoir (several kilometers underground) where steam or hot water that has been heated to high temperatures and pressures by the heat of magma is stored, and the steam or hot water is extracted from the geothermal reservoir through the well to the surface, and the extracted steam or hot water is used to rotate a turbine to generate electricity (see, for example, Patent Documents 1 and 2, etc.).

[0005] Conventional geothermal power generation has the advantage of being able to generate electricity stably regardless of weather or solar radiation, reducing the burden on the environment by reducing CO2 emissions during operation, and generating electricity using geothermal energy, which is an inexhaustible source of energy.

[0006] However, conventional geothermal power generation has the following drawbacks. (1) To reach a geothermal reservoir, it is necessary to drill several kilometers underground, and the cost of drilling a well alone can cost hundreds of millions of yen. In addition, geothermal power generation requires large-scale facilities, and building such facilities is extremely costly and takes a long time.

[0007] (2) Geothermal reservoirs are generally found in volcanic regions, which limits the locations where geothermal power generation facilities can be installed. Moreover, geothermal reservoirs are located in areas that overlap with national parks and hot spring areas. Therefore, prior to the installation of geothermal power generation facilities, an environmental assessment must be carried out to ensure that geothermal power generation does not have a negative impact on the local environment or tourism.

[0008] (3) Because it is very costly to dig a single well, drilling surveys must be carried out before drilling to identify possible locations of geothermal reservoirs, and these surveys also require cost and time.

[0009] In other words, construction of geothermal power generation facilities requires a long period of time and is extremely costly. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] JP 2010-270679 A [Patent Document 2] JP 2018-53738 A Summary of the Invention [Problem to be solved by the invention]

[0011] Therefore, an object of the present invention is to provide a small geothermal power generation device that is not subject to restrictions on installation location and can be easily installed at low cost. [Means for solving the problem]

[0012] In order to solve the above-mentioned problems, according to the present invention, there is provided a heat transfer device comprising: a heat transfer body formed in a rod shape; a first heat exchange section provided on one end side of the heat transfer body for heat exchange between the underground or the earth surface layer and the heat transfer body; and a second heat exchange section provided on the other end side of the heat transfer body for heat exchange between the earth surface layer or the outside air and the heat transfer body, wherein the first heat exchange section comprises: a first cylinder or square cylinder having thermal conductivity and surrounding an outer circumferential surface of the heat transfer body at the one end side of the heat transfer body; a heat transfer coupling structure arranged between the heat transfer body and the first cylinder or square cylinder and coupling the first cylinder or square cylinder to the heat transfer body in a thermally conductive manner; a second cylinder or square cylinder having thermal conductivity and surrounding the outside of the first cylinder or square cylinder at a certain interval; The present invention provides a geothermal power generation device comprising: at least one thermoelectric conversion module arranged between angular cylinders and in thermal contact with the first cylinder or angular cylinder on one side and in thermal contact with the second cylinder or angular cylinder on the other side; a first insulating member sealing an opening located on the one end side of the heat transfer body in the first and second cylinders or the first and second angular cylinders; and a second insulating member having a through hole to the heat transfer body and sealing an opening located on the other end side of the heat transfer body in the first and second cylinders or the first and second angular cylinders with the heat transfer body passing through the through hole, wherein electricity is extracted from the at least one thermoelectric conversion module in accordance with the temperature difference occurring between the first and second heat exchange sections.

[0013] According to a preferred embodiment of the present invention, the heat transfer and coupling structure of the first heat exchange section is composed of a plurality of heat transfer plates extending radially from the heat transfer body and in the axial direction of the heat transfer body and coupled to the first cylindrical or rectangular cylindrical body at their tip edges.

[0014] According to another preferred embodiment of the present invention, the heat transfer and coupling structure of the first heat exchange section comprises a plurality of heat transfer plates extending radially from the heat transfer body over the entire circumference of the heat transfer body at a plurality of positions spaced apart in the axial direction of the heat transfer body, and coupled at their tip edges to the first cylinder or rectangular cylinder.

[0015] According to yet another preferred embodiment of the present invention, the thermoelectric conversion module comprises a single thermoelectric conversion element formed in a plate or sheet shape, or a laminate in which a plurality of the thermoelectric conversion elements are stacked in the thickness direction so as to be thermally conductive to each other.

[0016] According to yet another preferred embodiment of the present invention, the geothermal power generation apparatus further includes a third insulating member covering a region of the heat transfer body between the first and second heat exchange portions.

[0017] According to yet another preferred embodiment of the present invention, the heat transfer body comprises at least one heat pipe. Effect of the Invention

[0018] The geothermal power generation device of the present invention is buried in the ground with an arrangement in which the first and second heat exchange units are located underground and above ground or in the surface layer, respectively (hereinafter referred to as the "first installation state"), or is buried in the surface layer with an arrangement in which the first and second heat exchange units are located in the surface layer and above ground, respectively (hereinafter referred to as the "second installation state").

[0019] In the first installation state, one end of the heat transfer body exchanges heat with the ground through the first heat exchange portion, and the other end of the heat transfer body exchanges heat with the outside air or the ground surface layer through the second heat exchange portion.

[0020] By the way, throughout the year and throughout the day, changes in the outside air temperature (air temperature), temperature changes at the earth's surface, and temperature changes underground each occur in different cycles and with different ranges of fluctuation. In particular, the annual change in underground temperature gradually decreases the deeper one goes underground, and at a depth of about 10 meters underground, the temperature is maintained at an almost constant level throughout the year (equivalent to the annual average temperature in that region).

[0021] As a result, throughout the year and throughout the day, there are alternating periods (hours) when the temperature underground is higher than the air or surface temperature, and periods (hours) when the opposite is true.

[0022] When the temperature underground is higher than the air temperature or the surface layer temperature, the heat from the underground is absorbed by one end of the heat transfer body through the first heat exchanger, moves to the other end of the heat transfer body, and is discharged to the outside air or the surface layer through the second heat exchanger. This heat transfer creates a temperature difference between the one side and the other side of each thermoelectric conversion module, and electricity is extracted from each thermoelectric conversion module.

[0023] On the other hand, when the temperature underground is lower than the air temperature or the surface layer temperature, the heat from the outside air or the surface layer is absorbed by the other end of the heat transfer body through the second heat exchanger, moves to one end of the heat transfer body, and is discharged into the ground through the first heat exchanger. This heat transfer creates a temperature difference between the one side and the other side of each thermoelectric conversion module, and electricity is extracted from each thermoelectric conversion module.

[0024] In the second installation state, one end of the heat transfer body exchanges heat with the ground surface through the first heat exchange portion, and the other end of the heat transfer body exchanges heat with the outside air through the second heat exchange portion.

[0025] When the temperature of the surface layer is higher than the air temperature, the heat of the surface layer is absorbed by one end of the heat transfer body through the first heat exchanger, moves to the other end of the heat transfer body, and is discharged into the outside air through the second heat exchanger. This heat transfer creates a temperature difference between the one side and the other side of each thermoelectric conversion module, and electricity is extracted from each thermoelectric conversion module.

[0026] On the other hand, when the temperature of the earth's surface is lower than the air temperature, heat in the outside air is absorbed by the other end of the heat transfer body through the second heat exchanger, moves to one end of the heat transfer body, and is discharged to the earth's surface layer through the first heat exchanger. This heat transfer creates a temperature difference between the one side and the other side of each thermoelectric conversion module, and electricity is extracted from each thermoelectric conversion module.

[0027] In this way, stable power generation is possible by effectively utilizing the temperature difference between the underground temperature and the air temperature or the temperature of the surface layer, or between the surface layer temperature and the air temperature, throughout the year and throughout the day.

[0028] Furthermore, in order to obtain the temperature difference necessary for practical levels of power generation using the geothermal power generation device of the present invention, it is sufficient for the geothermal power generation device of the present invention to have a length of 3 to 5 m, the length and width of the thermoelectric conversion module are on the order of a few centimeters to a few tens of centimeters, and the diameter of the heat transfer body is on the order of a few centimeters. That is, according to the present invention, a geothermal power generation device having a small size and simple structure can be provided.

[0029] Furthermore, the geothermal power generation device of the present invention can be installed anywhere there is a suitable temperature difference between the ground and the outside air or the surface layer, or between the surface layer and the outside air, and since it can be installed in a relatively small space, it is not subject to restrictions on installation location and can be easily installed at low cost. [Brief description of the drawings]

[0030] [Figure 1] FIG. 1A is a perspective view of a geothermal power generation apparatus according to one embodiment of the present invention, and FIGS. 1B and 1C are schematic views showing the installation state of the geothermal power generation apparatus. [Diagram 2] FIG. 2 is a vertical cross-sectional view of the geothermal power generation device of FIG. [Diagram 3] FIG. 2(A) is an exploded perspective view of a first heat exchanger of the geothermal power generation device of FIG. 1, and FIG. 2(B) is a cross-sectional view of the first heat exchanger. [Figure 4]FIG. 2(A) is a schematic perspective view showing a modified example of the first heat exchange section of the geothermal power generation apparatus in FIG. 1, and FIG. 2(B) is a vertical sectional view of the same modified example. [Diagram 5] FIG. 2A is a perspective view of a geothermal power generation apparatus according to another embodiment of the present invention, and FIG. 2B is a cross-sectional view of a first heat exchanger of the same geothermal power generation apparatus. [Figure 6] FIG. 6 is a vertical cross-sectional view of the geothermal power generation device of FIG. 5. [Figure 7] FIG. 6 is a perspective view of a third heat insulating member of the geothermal power generation apparatus of FIG. 5. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0031] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the configuration of the present invention will be described based on preferred embodiments with reference to the accompanying drawings. FIG. 1(A) is a perspective view of a geothermal power generation apparatus according to one embodiment of the present invention, and FIGS. 1(B) to (C) are schematic diagrams showing an installation state of the geothermal power generation apparatus.

[0032] 1(A) to 1(C), a geothermal power generation device 1 of the present invention includes a heat transfer body 2 formed in a rod shape, a first heat exchange section 3 provided on one end 2a of the heat transfer body 2 for heat exchange between the heat transfer body 2 and the underground X or a surface layer Y, and a second heat exchange section 4 provided on the other end 2b of the heat transfer body 2 for heat exchange between the heat transfer body 2 and the surface layer Y or outside air Z.

[0033] The heat conductor 2 is in this embodiment made of a metal or alloy having high thermal conductivity, preferably copper or aluminum.

[0034] Figure 2 is a longitudinal cross-sectional view of the geothermal power generation device of Figure 1, Figure 3(A) is an exploded oblique view of the first heat exchange section of the geothermal power generation device, and Figure 3(B) is a transverse cross-sectional view of the first heat exchange section.

[0035] As shown in Figures 2 and 3(A) to (B), in this embodiment, the first heat exchange section 3 comprises a first square cylinder 5 having thermal conductivity that surrounds the outer peripheral surface of the heat transfer body 2 on one end 2a side of the heat transfer body 2, a heat transfer coupling structure 6 that is arranged between the heat transfer body 2 and the first square cylinder 5 and thermally couples the first square cylinder 5 to the heat transfer body 2 in a manner that allows thermal conductivity, and a second square cylinder 7 having thermal conductivity that surrounds the outside of the first square cylinder 5 at a certain interval.

[0036] In this embodiment, the first and second rectangular cylinders 5, 7 both have a square cross section and the same length. However, the cross sections of the first and second rectangular cylinders 5, 7 are not limited to this shape and may be any polygonal shape as long as they are similar to each other.

[0037] The first and second rectangular cylinders 5, 7 are made of a metal or alloy having high thermal conductivity, preferably copper or aluminum.

[0038] In this embodiment, the heat transfer and coupling structure 6 is made up of a plurality of heat conductive plates 8 extending radially from the heat transfer body 2 in the axial direction of the heat transfer body 2 and coupled to the first rectangular cylinder 5 at their tip edges.

[0039] The heat-conducting plate 8, like the first and second rectangular cylinders 5, 7, is also made of a metal or alloy having high thermal conductivity, preferably copper or aluminum.

[0040] Preferably, the first and second rectangular tubular bodies 5, 7 and the heat conduction plate 8 are formed as thin as possible while maintaining a certain degree of rigidity, thereby improving the heat exchange and thermal conductivity of the first and second rectangular tubular bodies 5, 7 and the heat conduction plate 8.

[0041] The configuration of the heat transfer and bonding structure 6 is not limited to this embodiment, and may have any configuration that is arranged between the heat transfer body 2 and the first rectangular cylinder 5 and bonds the first rectangular cylinder 5 to the heat transfer body 2 in a thermally conductive manner.

[0042] 4(A) and (B) show another embodiment of the heat transfer and coupling structure 6. In FIG. As shown in Figures 4(A) to (B), in this embodiment, the heat transfer coupling structure 6' is composed of a plurality of heat transfer plates 8' which extend radially from the heat transfer body 2 over the entire circumference of the heat transfer body 2 at a plurality of positions spaced apart in the axial direction of the heat transfer body 2 and are coupled to the first rectangular cylinder 5 at their tip edges.

[0043] The heat conducting plate 8', like the heat conducting plate 8, is made of a metal or alloy having high thermal conductivity, preferably copper or aluminum.

[0044] The first heat exchange section 3 further includes at least one thermoelectric conversion module 9 having one surface 9a and the other surface 9b, arranged between the first and second rectangular cylinders 5, 7, and in thermal contact with the first rectangular cylinder 5 on one surface 9a and in thermal contact with the second rectangular cylinder 7 on the other surface 9b.

[0045] The thermoelectric conversion module 9 is made up of a single thermoelectric conversion element formed in a plate or sheet shape, or a laminate in which a plurality of such thermoelectric conversion elements are stacked in the thickness direction so as to be capable of thermally conducting between each other.

[0046] In the latter configuration, the thermoelectric conversion elements in the stack are electrically connected in series with each other, so that even if the temperature difference between one side and the other side of the thermoelectric conversion module 9 is the same, a larger output can be obtained than with a thermoelectric conversion module 9 formed from a single thermoelectric conversion element. In this embodiment, the thermoelectric conversion module 9 is made up of a laminate of a plurality of thermoelectric conversion elements.

[0047] As the thermoelectric conversion element, a known thermoelectric conversion element, for example, one utilizing the Seebeck effect or the spin Seebeck effect, is used.

[0048] In this embodiment, one thermoelectric conversion module 9 is disposed on each of the four side surfaces of the first rectangular cylinder 5, and the four thermoelectric conversion modules 9 are electrically connected in series to each other. The number of thermoelectric conversion modules 9 arranged per side surface of the first rectangular cylinder 5 is not limited to this embodiment, but may be any number.

[0049] Furthermore, the electrical connection method of each thermoelectric conversion module 9 is not limited, and all thermoelectric conversion modules 9 may be connected in series, or the thermoelectric conversion modules 9 may be divided into multiple groups, the thermoelectric conversion modules in the same group may be connected in series, and each group may be connected in parallel.

[0050] The first heat exchange section 3 further includes a first insulating member 10 that seals an opening located on one end 2a of the heat transfer body 2 in the first and second rectangular cylinders 5, 7, and a second insulating member 11 that has a through hole 11a for the heat transfer body 2 and seals an opening located on the other end 2b of the heat transfer body 2 in the first and second rectangular cylinders 5, 8 with the heat transfer body 2 passing through the through hole 11a.

[0051] In this embodiment, the second heat exchange section 4 is formed in a rectangular shape, each having a through hole in the center for the heat conductor 2, and is composed of a plurality of heat conduction plates 12 that are attached to the heat conductor 2 in a thermally conductive manner at a plurality of positions spaced apart in the axial direction on the other end 2b side of the heat conductor 2, with the heat conductor 2 passing through the through holes. The heat-conducting plate 12 is made of a metal or alloy having high thermal conductivity, preferably copper or aluminum.

[0052] Preferably, a third heat insulating member covering the area between the first and second heat exchange sections 3, 4 in the heat transfer body 2 is further provided.

[0053] Next, the operation of this geothermal power generation device 1 will be described. The geothermal power generation device 1 is buried in the ground X with the first and second heat exchange units 5, 7 located in the ground X and above ground (or in the ground surface layer Y), respectively (hereinafter referred to as the "first installation state"), or buried in the ground surface layer Y with the first and second heat exchange units 5, 7 located in the ground surface layer Y and above ground, respectively (hereinafter referred to as the "second installation state").

[0054] FIG. 1(B) is a schematic diagram showing the geothermal power generation apparatus 1 in a first installation state, and FIG. 1(C) is a schematic diagram showing the geothermal power generation apparatus 1 in a second installation state. As shown in Figure 1 (C), in the second installation state, if necessary, a suitable additional support means 13 is attached to the lower part of the first heat exchange section 5 of the geothermal power generation equipment 1 to prevent the geothermal power generation equipment 1 from tilting due to wind pressure, etc., and to keep the installation state of the geothermal power generation equipment 1 stable.

[0055] Referring to FIG. 1(B), in a first installation state, one end side 2a of the heat transfer body 2 exchanges heat with the ground X through a first heat exchange section 5, and the other end side 2b of the heat transfer body 2 exchanges heat with the outside air Z (or the ground surface layer Y) through a second heat exchange section 7.

[0056] By the way, throughout the year and throughout the day, the changes in the temperature (air temperature) of the outside air Z, the temperature changes in the surface layer Y, and the temperature changes underground X each occur in different cycles and with different fluctuation ranges. In particular, the annual change in temperature underground at X becomes gradually smaller the deeper one goes underground, and at a depth of about 10 m underground, the temperature is maintained at an almost constant level throughout the year (corresponding to the annual average temperature in that area).

[0057] Therefore, throughout the year and throughout the day, there are alternating periods (hours) when the temperature of underground X is higher than the air temperature or the temperature of surface layer Y, and periods (hours) when the opposite is true.

[0058] When the temperature of the underground X is higher than the air temperature (or the temperature of the earth's surface layer Y), the heat of the underground X is absorbed by one end 2a of the heat transfer body 2 through the first heat exchange section 3, moves to the other end 2b of the heat transfer body 2, and is discharged into the outside air Z (or the earth's surface layer Y) through the second heat exchange section 4. As a result of this heat transfer, a temperature difference occurs between the one surface 9a and the other surface 9b of each thermoelectric conversion module 9, and electricity is extracted from each thermoelectric conversion module 9.

[0059] On the other hand, when the temperature of the ground X is lower than the air temperature or the temperature of the ground surface layer Y, the heat in the outside air Z or the ground surface layer Y is absorbed by the other end 2b of the heat transfer body 2 through the second heat exchange section 4, moves to the one end 2a of the heat transfer body 2, and is discharged to the ground X through the first heat exchange section 3. As a result of this heat transfer, a temperature difference occurs between the one surface 9a and the other surface 9b of each thermoelectric conversion module 9, and electricity is extracted from each thermoelectric conversion module 9.

[0060] Referring to Figure 1 (C), in the second installation state, one end 2a of the heat transfer body 2 exchanges heat with the ground surface layer Y through the first heat exchange section 3, and the other end 2b of the heat transfer body 2 exchanges heat with the outside air Z through the second heat exchange section 4.

[0061] When the temperature of the ground surface layer Y is higher than the air temperature, the heat of the ground surface layer Y is absorbed by one end 2a of the heat transfer body 2 through the first heat exchange section 3, moves to the other end 2b of the heat transfer body 2, and is discharged into the outside air Z through the second heat exchange section 4. As a result of this heat transfer, a temperature difference occurs between the one surface 9a and the other surface 9b of each thermoelectric conversion module 9, and electricity is extracted from each thermoelectric conversion module 9.

[0062] On the other hand, when the temperature of the ground surface layer Y is lower than the air temperature, the heat in the outside air Z is absorbed from the second heat exchange section 4 to the other end 2b of the heat transfer body 2, moves to the one end 2a of the heat transfer body 2, and is discharged to the ground surface layer Y through the first heat exchange section 3. As a result of this heat transfer, a temperature difference occurs between the one surface 9a and the other surface 9b of each thermoelectric conversion module 9, and electricity is extracted from each thermoelectric conversion module 9.

[0063] When the temperature of the ground X and the air temperature (or the temperature of the surface layer Y), or the temperature of the surface layer Y and the air temperature, reverses, the polarity of the current output from the thermoelectric conversion module 9 is accordingly reversed, so that in actual operation of the geothermal power generation device 1, an appropriate polarity reversal circuit (not shown) is provided between the geothermal power generation device 1 and a device (electronic device, storage battery, etc.) that receives power from it. Also, if necessary, a step-up DC-DC converter or a power conditioner is provided downstream of the polarity reversal circuit.

[0064] In this way, by effectively utilizing the temperature difference between the underground temperature X and the air temperature or the temperature of the surface layer Y, or between the temperature of the surface layer Y and the air temperature throughout the year and throughout the day, stable power generation is possible.

[0065] In order to obtain the temperature difference necessary for practical level power generation using the geothermal power generation device 1 of the present invention, it is sufficient for the geothermal power generation device 1 to have a length of 3 to 5 m, and the size of the thermoelectric conversion module 9 is on the order of a few centimeters to a few tens of centimeters, and the diameter of the heat transfer body 2 is on the order of a few centimeters. That is, according to the present invention, it is possible to provide a geothermal power generation device 1 that is small in size and has a simple structure.

[0066] Furthermore, the geothermal power generation device 1 of the present invention can be installed anywhere where there is an appropriate temperature difference between the underground X and the outside air Z or the surface layer Y of the earth, or between the surface layer Y and the outside air Z, and since it can be installed in a relatively small space, it is not subject to restrictions on the installation location and can be easily installed at low cost.

[0067] In addition, since the geothermal power generation device 1 of the present invention does not require its own power source, it incurs no running costs and almost no maintenance costs, making it very economical.Furthermore, since it functions as an off-grid power generation device that is separated from the general power grid, it can be effectively used as an emergency power supply device in the event of a disaster.

[0068] Although a preferred embodiment of the present invention has been described above, it goes without saying that the configuration of the present invention is not limited to the above-described embodiment, and that a person skilled in the art can devise various modifications within the scope of the configuration described in the appended claims.

[0069] For example, in the above-described embodiment, the heat transfer body 2 is formed from a metal or alloy having high thermal conductivity, preferably copper or aluminum, but instead the heat transfer body 2 may be formed from a single heat pipe or a bundle of multiple heat pipes.

[0070] According to this configuration, when the geothermal power generation apparatus 1 is in the first arrangement state, mainly when the temperature of the underground X is higher than the air temperature or the temperature of the surface layer Y, and when the geothermal power generation apparatus 1 is in the second arrangement state, mainly when the temperature of the surface layer Y is higher than the air temperature, highly efficient heat transfer from the first heat exchange body 3 side to the second heat exchange body 4 side can be achieved (the thermal conductivity of the heat pipe is several to several tens of times that of copper), thereby realizing higher-output power generation.

[0071] In addition, in the above-described embodiment, the first heat exchange section 3 comprises first and second rectangular cylindrical bodies 5, 7, but the first heat exchange section 3 may comprise a small diameter cylindrical body and a large diameter cylindrical body instead of the first and second rectangular cylindrical bodies 5, 7.

[0072] Furthermore, the configuration of the second heat exchange section 4 is not limited to the above-mentioned embodiment, and the second heat exchange section 4 may have any configuration that achieves efficient heat exchange between the other end 2b side of the heat transfer body 2 and the outside air Z (or the ground surface layer Y).

[0073] Fig. 5(A) is a perspective view of a geothermal power generation device according to another embodiment of the present invention, and Fig. 5(B) is a cross-sectional view of a first heat exchanger of the geothermal power generation device. Fig. 6 is a vertical cross-sectional view of the geothermal power generation device shown in Fig. 5, and Fig. 7 is a perspective view of a third insulating member of the geothermal power generation device shown in Fig. 5. In FIG. 5, the same components as those shown in FIGS. 1 to 4 are denoted by the same reference numerals, and detailed description thereof will be omitted below.

[0074] Referring to Figures 5 to 6, in this embodiment, the geothermal power generation apparatus 1' has, in addition to the configuration of the geothermal power generation apparatus 1 shown in Figures 1 to 4, a third insulating member 14 having a rectangular tube shape extending from the first insulating member 10, through the gap between the first and second rectangular tubes 5, 7, to the boundary between the heat transfer body 2 and the second heat exchange section 4.

[0075] The third heat insulating member 14 is formed of four rectangular heat insulating plates 15 each having a thickness corresponding to the gap between the first and second rectangular cylinders 5, 7. The outer edge of the cross section of the inner space of the third heat insulating member 14 is a square corresponding to the outer edge of the square cross section of the first rectangular cylinder 5, and the outer edge of the cross section of the third heat insulating member 14 is a square corresponding to the inner edge of the square cross section of the second rectangular cylinder 7.

[0076] Furthermore, openings 15a having a shape corresponding to the shape of the thermoelectric conversion module 9 are formed in the lower part of each side wall of the third heat insulating member 14 at positions corresponding to the thermoelectric conversion module 9. The opening of the third heat insulating member 14 on the second heat exchange section 4 side is closed by the second heat insulating member 11.

[0077] It goes without saying that in this embodiment as well, the same effects as those in the embodiment shown in FIGS. 1 to 4 can be obtained. [Explanation of symbols]

[0078] 1, 1´ Geothermal power generation device 2. Heat Transfer Material 2a one end 2b other end 3. First heat exchange section 4 Second heat exchange section 5. First rectangular cylinder 6, 6´ Heat transfer and bonding structure 7 Second rectangular tube 8, 8´ heat conduction plate 9 Thermoelectric conversion module 9a one side 9b Other side 10 First heat insulating member 11 Second insulation member 11a Through hole 12 Heat conduction plate 13 Support means 14 Third insulation member 15 Insulation board 15a opening X underground Y surface layer Z Outside air

Claims

1. A rod-shaped heat transfer body; a first heat exchange section provided on one end side of the heat transfer body for heat exchange between the underground or the earth surface layer and the heat transfer body; a second heat exchange section provided on the other end side of the heat transfer body for exchanging heat between the ground surface layer or the outside air and the heat transfer body; The first heat exchange section includes: a first cylindrical body or a square cylindrical body having thermal conductivity surrounding an outer peripheral surface of the heat transfer body at the one end side of the heat transfer body; a heat transfer and coupling structure disposed between the heat transfer body and the first cylindrical body or the rectangular cylindrical body, the heat transfer and coupling structure coupling the first cylindrical body or the rectangular cylindrical body to the heat transfer body in a thermally conductive manner; a second cylindrical body or a rectangular cylindrical body having thermal conductivity and surrounding the outside of the first cylindrical body or the rectangular cylindrical body at a certain interval; at least one thermoelectric conversion module having one surface and another surface, disposed between the first and second cylindrical bodies or between the first and second rectangular cylindrical bodies, and in thermal contact with the first cylindrical body or the rectangular cylindrical body at the one surface and in thermal contact with the second cylindrical body or the rectangular cylindrical body at the other surface; a first heat insulating member that seals an opening located on the one end side of the heat transfer body in the first and second cylindrical bodies or the first and second rectangular cylindrical bodies; a second heat insulating member that has a through hole for the heat transfer body and seals an opening located on the other end side of the heat transfer body in the first and second cylinders or the first and second rectangular cylinders when the heat transfer body passes through the through hole; A geothermal power generation device, characterized in that electric power is extracted from the at least one thermoelectric conversion module in response to a temperature difference occurring between the first and second heat exchange sections.

2. The geothermal power generation device described in claim 1, characterized in that the heat transfer and connection structure of the first heat exchange section consists of a plurality of heat transfer plates extending radially from the heat transfer body and in the axial direction of the heat transfer body and connected to the first cylinder or rectangular cylinder at their tip edges.

3. The geothermal power generation device described in claim 1, characterized in that the heat transfer and connection structure of the first heat exchange section consists of a plurality of heat transfer plates extending radially from the heat transfer body along the entire circumference of the heat transfer body at a plurality of positions spaced apart in the axial direction of the heat transfer body, and connected to the first cylinder or rectangular cylinder at their tip edges.

4. The geothermal power generation device according to claim 1, characterized in that the thermoelectric conversion module is composed of a single thermoelectric conversion element formed in a plate or sheet shape, or a laminate in which a plurality of the thermoelectric conversion elements are stacked in the thickness direction so as to be capable of thermally conducting between each other.

5. 2. The geothermal power generation device according to claim 1, further comprising a third heat insulating member covering an area between the first and second heat exchange portions in the heat transfer body.

6. 6. The geothermal power generation device according to claim 1, wherein the heat transfer body is made of at least one heat pipe.

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