Thermoelectric conversion unit, thermoelectric power generation system, and heat sink used therein

Abstract

To provide a thermoelectric conversion unit suitable for a mobile body.SOLUTION: A thermoelectric conversion unit mounted on a curved surface 112 of a heat-generating element 110 of a mobile body 100 comprises: a thermoelectric circuit module 10 in which thermoelectric conversion elements 11 are implemented and which has a first principal surface 15 and a second principal surface 16 that are capable of being curved; and a radiator 20 that is made of a metal plate material, has a plurality of plate-like radiation fins 22 formed so as to be erected integrally with a base 21 on a front side 26, the base 21 being capable of being curved, and is laminated on the thermoelectric circuit module 10 so that a rear surface 25 is in tight contact with the second principal surface of the thermoelectric circuit module 10. The plurality of radiation fins 22 are arranged so that pitches at a base end 21 have predetermined values within a range of 1.0 mm to 2.5 mm.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a thermoelectric conversion unit, a thermoelectric power generation system, and a radiator used therein. [Background technology]

[0002] Efforts have been made to recover heat wasted from a heat generating element and reuse it as electrical energy (see, for example, Patent Documents 1 and 2). Patent Documents 1 and 2 describe a method in which a thermoelectric conversion unit is prepared by stacking a base plate or a flexible heat-conducting substrate above a thermoelectric circuit module on which a Seebeck element (thermoelectric conversion element) is mounted, and then joining a heat dissipation fin array onto the base plate or a flexible heat-conducting substrate, and then attaching the thermoelectric conversion unit to an exhaust heat pipe (heat generating body) of a plant factory or the like to generate thermoelectric power.

[0003] The thermoelectric conversion units described in Patent Documents 1 and 2 are flexible, and when attached to an exhaust heat pipe or the like, they can be tightly attached to the outer surface of the exhaust heat pipe or the like. This increases the contact area compared to when a non-flexible thermoelectric conversion unit (e.g., thermoelectric units 1, 11, and 21 in Patent Document 3) is used, allowing for efficient use of waste heat from the exhaust heat pipe or the like. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2020-10559 [Patent Document 2] Japanese Patent Application Publication No. 2019-198165 [Patent Document 3] JP 2014-49734 A Summary of the Invention [Problem to be solved by the invention]

[0005] In vehicles such as four-wheeled and two-wheeled vehicles, which are a type of mobile object, the temperature of the gases emitted from the engine in the exhaust system can reach several hundred degrees, so the installation of forced cooling systems for the exhaust system, such as exhaust pipes, is becoming more common.With the current trend toward creating a sustainable society, the recovery and effective use of thermal energy in mobile objects can also be said to be an important theme. However, for mobile vehicles, there is also a demand for improved energy efficiency during movement (for example, reducing air resistance and pressure loss) and lighter thermoelectric conversion units, and efforts to achieve both of these goals, along with the recovery and effective use of thermal energy, will become increasingly important in the future.

[0006] In the thermoelectric conversion units described in Patent Documents 1 and 2, although it is mentioned that a heat dissipation fin array (heat sink) is attached to a thermoelectric circuit module via a base plate, there is no consideration of thermoelectric conversion units or heat sinks suitable for mobile objects.

[0007] The present invention has been made in view of the above circumstances, and has an object to provide a thermoelectric conversion unit suitable for a mobile body, and a radiator and a thermoelectric power generation system suitable for such a thermoelectric conversion unit. [Means for solving the problem]

[0008] The inventors of the present invention conducted extensive research and discovered a thermoelectric conversion unit configuration that is optimal for mounting on a heat-generating body of a mobile object. One aspect of the present invention provides a thermoelectric conversion unit that can be mounted on a curved surface of a heat-generating body. The thermoelectric conversion unit includes: a thermoelectric circuit module on which thermoelectric conversion elements are mounted, the module having a first main surface and a second main surface opposite the first main surface that are bendable; and a heat sink made of a metal plate, the heat sink having a plurality of plate-shaped heat dissipation fins formed integrally with a base on the front side and extending upward, the base being bendable, and the heat sink being stacked on the thermoelectric circuit module so that the back surface is in close contact with the second main surface of the thermoelectric circuit module. The thermoelectric conversion unit is mounted on a heat-generating body associated with a mobile object, and the plurality of heat dissipation fins are arranged at a predetermined pitch at their base ends within a range of 1.0 mm to 2.5 mm.

[0009] According to another aspect, the thermoelectric conversion unit is configured such that, when attached to the curved surface of a given heat generating body, the tips of adjacent heat dissipation fins are spaced apart at a predetermined distance within the range of 1.1 mm to 1.8 mm.

[0010] In addition, the thermoelectric power generation system of the present invention is a thermoelectric power generation system that converts heat emitted from a heat generating element attached to a mobile object into electrical energy, and includes at least the above-mentioned thermoelectric conversion unit and a storage unit that stores the power output from the thermoelectric circuit module of the thermoelectric conversion unit.

[0011] Furthermore, the present invention provides a heat sink for use in a thermoelectric conversion unit mounted on a curved surface of a heat generating body attached to a mobile object, the heat sink being stacked in close contact with a thermoelectric circuit module having a thermoelectric conversion element mounted thereon to form a thermoelectric conversion unit together with the thermoelectric circuit module, the heat sink being made of a metal plate and having a plurality of plate-shaped heat dissipation fins formed upright integrally with a base on the front side, the base being bendable, and the plurality of heat dissipation fins being arranged at a predetermined pitch at the base end within a range of 1.0 mm to 2.5 mm.

[0012] According to another aspect, the heat sink is configured so that when the thermoelectric conversion unit is attached to the curved surface of a given heat generating body, the tips of adjacent heat sink fins are spaced apart at a predetermined distance within the range of 1.1 mm to 1.8 mm. [Effects of the Invention]

[0013] According to the present invention, it is possible to provide a thermoelectric conversion unit suitable for a mobile body, and also to provide a radiator and a thermoelectric power generation system suitable for such a thermoelectric conversion unit. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a perspective view showing a manufacturing example of a thermoelectric conversion unit 1 according to a first embodiment and an example of attachment to a heating element 110. FIG. [Figure 2] 1 is a side view of a thermoelectric conversion unit 1 according to a first embodiment. [Figure 3] 1(c) is a side view of the thermoelectric conversion unit 1 according to the first embodiment attached to the heat generating element 110, as viewed along the arrow B in FIG. [Figure 4] 10 is a table and graphs showing the results of thermal analysis in a simulation example. [Figure 5] FIG. 10 is a perspective view showing a main part of a thermoelectric conversion unit 2 according to a second embodiment. [Figure 6] FIG. 10 is a perspective view showing a main part of a thermoelectric conversion unit 3, 3' according to a third embodiment. [Figure 7] FIG. 10 is a schematic diagram illustrating a thermoelectric power generation system 50 according to a fourth embodiment. [Figure 8] 10 is a diagram showing an application example of a heat sink 20 according to a fifth embodiment. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0015] The thermoelectric conversion unit, thermoelectric power generation system, and radiator used therein according to the present invention will be described below with reference to the drawings. Note that the explanations already given for symbols common to all figures can be used in the explanations of the other figures, and therefore explanations in the other figures will be omitted. Each figure is a schematic diagram showing an example, and does not necessarily strictly reflect actual dimensions, proportions, etc. In this specification, "upper" and "lower" are provisionally defined as meaning one side of a given plane as upper and the other side as lower, and do not directly relate to the top and bottom of the actual thermoelectric conversion unit placement.

[0016] [Embodiment 1] 1. Configuration of thermoelectric conversion unit 1 according to embodiment 1 (1) Overview of Thermoelectric Conversion Unit 1 First, an overview of the thermoelectric conversion unit 1 will be described along with an example of its manufacture and an example of its attachment to the heating element 110. 1 is a perspective view showing a manufacturing example of a thermoelectric conversion unit 1 according to embodiment 1 and an example of attachment to a heating element 110. Fig. 1(a) shows a state before a heat sink 20 is stacked on a thermoelectric circuit module 10, Fig. 1(b) shows a state in which the heat sink 20 is stacked on the thermoelectric circuit module 10 to complete the thermoelectric conversion unit 1, and Fig. 1(c) shows a state in which the thermoelectric conversion unit 1 is assumed to be attached to an exhaust pipe 210 (heat sink 110).

[0017] As shown in Figures 1(a) and 1(b), the thermoelectric conversion unit 1 is broadly composed of a thermoelectric circuit module 10 and a heat sink 20, which are stacked so that the back surface 25 of the heat sink 20 is in close contact with the second main surface 16 of the thermoelectric circuit module 10 (see also Figure 2). The first main surface 15 of the thermoelectric circuit module 10 and a second main surface 16, which is the surface opposite to the first main surface 15, are bendable. The heat radiator 20 also has a bendable base 21 (described later). Therefore, the entire thermoelectric conversion unit 1 is bendable about an imaginary axis that is approximately parallel to the longitudinal direction LD of the heat radiating fins 22 (described later) of the heat radiator 20.

[0018] 1(c), the thermoelectric conversion unit 1 is a unit that is attached to a curved surface 112 of a heat generating element 110. In particular, the thermoelectric conversion unit 1 according to the first embodiment is configured to be attached to a heat generating element 110 that is attached to a moving object 100 (see FIG. 7). For example, it is configured to be attached to a curved surface (the outer surface of the pipe) of an exhaust pipe 210 of a four-wheeled vehicle driven by an engine.

[0019] The "mobile body 100" referred to here includes land-based mobile bodies such as four-wheeled vehicles, two-wheeled vehicles, and railroad cars, airborne mobile bodies such as drones, and water-based mobile bodies such as ships. The type of drive source (engine, motor, etc.) of these mobile bodies 100 is not particularly limited, and the first embodiment can be applied. The thermoelectric conversion unit 1 of the first embodiment is configured assuming that the standard travel speed of the mobile body 100 is approximately 30 km / h to 60 km / h. An example of the heating element 110 attached to the moving object 100 is an exhaust pipe 210 that circulates gas exhausted from the engine 205 inside (see FIG. 7). Other examples of the heating element 110 include a battery (which has a curved shape such as a cylindrical shape), a motor, etc.

[0020] (2) Thermoelectric circuit module 10 The thermoelectric circuit module 10 is a module configured with an electrical circuit for converting thermal energy into electrical energy. A thermoelectric conversion element 11 is mounted on the thermoelectric circuit module 10. The thermoelectric conversion element 11 may be any element that converts thermal energy into electrical energy, and for example, a Seebeck element that produces the Seebeck effect can be used.

[0021] The thermoelectric circuit module 10 can be configured, for example, from a flexible printed circuit board (not shown) on which a plurality of thermoelectric conversion elements 11 are mounted, and flexible protective boards that sandwich the flexible printed circuit board from above and below. The thermoelectric circuit module 10 has a flat plate shape with two main surfaces when placed on a plane. The first main surface 15 is used as a heat absorption surface that comes into close contact with the heat generating element 110, and the second main surface 16 is used as a heat dissipation surface that comes into close contact with the heat sink 20 (described later). The thermoelectric circuit module 10 is capable of elastic deformation (including bending) so that the first main surface 15 and the second main surface 16 have a predetermined radius of curvature. Even after being combined with the heat sink 20, the thermoelectric circuit module 10 is capable of some kind of elastic deformation at least about an imaginary axis that is approximately parallel to the longitudinal direction LD of the heat dissipation fins 22 of the heat sink 20.

[0022] (3) Heat sink 20 Next, the heat sink 20 will be described. Figure 2 is a side view of the thermoelectric conversion unit 1 according to embodiment 1. Figure 2(a) is a side view of the thermoelectric conversion unit 1 as viewed along arrow A in Figure 1(b), and Figure 2(b) is an enlarged side view of a main part of the area surrounded by dashed line C in Figure 2(a).

[0023] 2(a), the heat sink 20 has a plurality of plate-shaped heat dissipating fins 22 formed upright on the front side 26 and integrally with the base 21. The heat dissipating fins 22 being "integrally formed" with the base 21 means that the base 21 and the heat dissipating fins 22 are formed integrally and continuously. The base 21 conducts heat from the rear surface (the surface on which the thermoelectric circuit module 10 is arranged) and transfers it to the heat dissipation fins 22. The base 21 supports the plurality of heat dissipation fins 22 near the base ends 23 of the heat dissipation fins 22 (see FIG. 2(b)). The heat dissipation fins 22 dissipate the heat conducted from the base 21 to a refrigerant passing through the gaps between adjacent heat dissipation fins 22 (specifically, to wind W or the like accompanying the movement of the moving body 100 (see FIG. 7)).

[0024] Focusing on a single heat dissipation fin 22, the heat dissipation fin 22 of the first embodiment is flat. The base end 23 of the heat dissipation fin 22 is connected to the base 21, and the tip 24 of the heat dissipation fin 22 protrudes upward to form a long protrusion extending along the longitudinal direction LD (see FIG. 1) of the heat dissipation fin. The heat dissipation fins 22 are arranged parallel to one another along the longitudinal direction LD of the heat dissipation fins. The thermoelectric conversion unit 1 of the first embodiment is attached to a heat generating body 110 attached to a moving body 100, and is configured to be arranged so that the longitudinal direction LD of the heat dissipation fins is substantially aligned with the traveling direction MV of the moving body 100 (see FIG. 7). Therefore, for example, when the thermoelectric conversion unit 1 is attached to the curved surface 112 of the exhaust pipe 210, the heat dissipation fins 22 are arranged at predetermined intervals along a direction parallel to the pipe axis AX of the exhaust pipe 210.

[0025] As shown in FIG. 2(b), the plurality of heat dissipation fins 22 are arranged with a predetermined pitch of p at their base ends 23. When the thermoelectric conversion unit 1 is placed upright on a flat surface, the pitch of the heat dissipation fins 22 at their tips 24 is also approximately the same as p. The base 21 has a thickness T1. The heat dissipation fins 22 of embodiment 1 have a substantially uniform thickness t. A gap of g is formed between adjacent heat dissipation fins 22 near their base ends 23.

[0026] The heat sink 20 is made of a metal plate material, such as aluminum material such as pure aluminum (A1050), copper material, or the like.

[0027] The thickness T1 of the base 21 of the heat sink 20 is set to a value that allows elastic deformation to a degree that achieves the functions and effects of embodiment 1, and is also strong enough to maintain the shape and function of the heat sink 20.

[0028] Fig. 3 is a side view of the thermoelectric conversion unit 1 according to embodiment 1 when attached to the heating element 110, as viewed along the arrow B in Fig. 1(c). Fig. 3(a) is a side view of the thermoelectric conversion unit 1 and the heating element 110 when viewed along the arrow B in Fig. 1(c), and Fig. 3(b) is an enlarged side view of the main part of the area surrounded by the dashed line D in Fig. 3(a).

[0029] As shown in Figure 3, when the entire thermoelectric conversion unit 1 is curved and attached to the curved surface 112 of the heating element 110, the heat dissipation fins 22 expand radially in the radial direction, and the gap near the tip 24 of the heat dissipation fin 22 becomes larger than the gap g near the base end 23. When the thermoelectric conversion unit 1 is attached to the curved surface 112 of the heat generating element 110, the distance (opening width) between the tips of the adjacent heat dissipation fins 22 is designated as OP (see FIG. 3(b)).

[0030] In one example of the first embodiment, the heat sink 20 is formed by digging out the surface of a metal plate with the blade of a cutting tool, so that a plurality of plate-shaped heat sink fins 22 are formed upright integrally with the base 21. Regarding the method of configuring such a heat sink 20, for example, the description of the manufacturing technology for heat sink fins described in Japanese Patent Laid-Open Publication No. 2014-212290 by the same applicant can be directly incorporated into this specification.

[0031] As an example of the first embodiment, it is also possible to configure the system by setting p to 2.0 mm, t to 1.0 mm, g to 1.0 mm, T1 to 5.0 mm, and OP to 1.47 mm.

[0032] 2. Simulation example The inventors performed thermal analysis through simulation and obtained new knowledge about the optimum radiator for a thermoelectric conversion unit to be mounted on a moving object, which will be described below. FIG. 4 is a table and graphs showing the results of the thermal analysis in the simulation example.

[0033] (1) Simulation conditions (a) Sample As a sample, a thermoelectric conversion unit 1 according to embodiment 1 was prepared. However, the thermoelectric circuit module 10 was fixed, and for convenience, it was assumed that heat from the heating element 110 passes directly through the thermoelectric circuit module 10 and is transferred to the heat sink 20, and the simulator was set up under the assumption that a predetermined amount of heat is directly supplied from the rear surface 25 of the heat sink 20.

[0034] The specifications common to all samples (described below) were that the width of the heat sink 20 when placed upright on a flat surface was 400 mm (in the width direction of the paper in FIG. 1(b)) and the depth was 200 mm (the length of the heat sink fins 22 in the longitudinal direction LD was also equal to this). The thickness T1 of the base 21 was set to 5 mm, and the height from the base end 23 to the tip 24 of the heat sink fins 22 was set to 25 mm. The material of the heat sink 20 was pure aluminum (A1050).

[0035] (b) Heat generation and heat dissipation conditions In the simulation, the heatsink 20 was assumed to be curved, with a width of 400 mm and a circle that circled 360 degrees around the tube axis AX. Specifically, a cylindrical shape was formed as shown in Figure 1(c). For reference, the diameter of the circle formed by the back surface 25 of the heatsink 20 in this case was approximately 127.3 mm. A single heat source with a heat output of 2000 W was placed in contact with the entire back surface 25 (400 mm × 200 mm) of the heat sink 20, and heat was applied uniformly to the bottom surface of the back surface 25. Note that when the thermoelectric conversion unit 1 is implemented, the thermoelectric circuit module 10 is interposed between the heating element 110 and the heat sink 20, but as mentioned above, for convenience, the simulation was performed under the assumption that the first main surface 15 and the second main surface 16 of the thermoelectric circuit module 10 are at the same temperature as the surface temperature of the heating element 110. On the other hand, regarding the heat dissipation conditions, the cooling medium was air at 60°C, and the cooling medium was sent uniformly to the entire heat sink 20 from the side of the heat dissipation fin 22 at a speed of 60 km / h (see also the direction of the wind W arrow in Figure 1(c)).

[0036] (c) Simulation Under the common specifications of (a) and (b) above, the arrangement pitch p of the heat dissipation fins 22 near the base end 23 was used as an input variable, and thermal analysis was performed using six values ​​of p (p = 0.5 mm, 1.0 mm, 1.5 mm, 2.0 mm, 2.5 mm, 3.0 mm) (see the second row of the table in Figure 4). Note that the thickness t of the heat dissipation fins was set to 1 / 2 of the arrangement pitch p of the heat dissipation fins 22, and the gap g between adjacent heat dissipation fins near the base was also set to 1 / 2 of the arrangement pitch p (see the row marked "Reference" in the table in Figure 4). Furthermore, as described above, the premise is to form a cylinder that goes around 360 degrees across the entire width of the heat sink 20, so once the arrangement pitch p of the heat sink fins 22 near the base end 23 is determined, the spacing (opening) OP of the tips of the heat sink fins 22 is also determined (see the second row of the table in Figure 4).

[0037] While varying the above parameters, the output variables were obtained: maximum temperature Tw [°C] on the back surface 25 of the radiator 20, thermal resistance R [K / W] of the radiator 20, and pressure loss PL [Pa] when air passes near the radiator 20. The thermal resistance R was derived as R = (Tw - T∞) / Q (where R [°C / W] is thermal resistance, Q [W] is the amount of heat, Tw [°C] is the maximum temperature on the back surface 25 of the radiator fin, and T∞ [°C] is the temperature of the cooling medium). The software used for the simulation was "Thermo-Calc(R)".

[0038] (2) Simulation results 4, it was confirmed that as the arrangement pitch p of the heat dissipation fins 22 increases, the maximum temperature Tw also increases, the thermal resistance R also increases, and the heat dissipation characteristics deteriorate. Conversely, in areas where the arrangement pitch p is small, the heat dissipation characteristics were relatively good. On the other hand, the fluid dynamic characteristics were favorable, with the pressure loss PL decreasing as the arrangement pitch p of the heat dissipation fins 22 increased. Conversely, in the region where the arrangement pitch p of the heat dissipation fins 22 was small, the pressure loss PL deteriorated, especially at level 2 (p = 1.0 mm), and further deteriorated rapidly at level 1 (p = 0.5).

[0039] (3) Consideration When the arrangement pitch p of the heat dissipation fins 22 is increased, the number of fins is reduced and the spacing OP between the tips 24 is also increased. This means that even air with a certain degree of viscosity can easily enter the gaps between adjacent heat dissipation fins 22 (improving ventilation), making it easier to expel heated air. On the other hand, the reduced number of fins reduces the contact area with the air, which tends to reduce heat dissipation and worsen the heat dissipation characteristics. In addition, the thickness t of the heat dissipation fins 22 is set to be large, which is disadvantageous for reducing the weight of the thermoelectric conversion unit 1. Conversely, if the arrangement pitch p of the heat dissipation fins 22 is small, the gap between the adjacent heat dissipation fins 22 becomes small, the air resistance between the flowing air and the heat dissipation fins 22 increases, and the pressure loss PL also worsens as shown in the graph, which tends to be unfavorable in terms of fluid dynamics for the moving body 100. In addition, since the thickness t of the heat dissipation fins 22 is set to be small, the capacity for heat conducted from the base 21 decreases, which is unfavorable for heat dissipation. In this way, as the arrangement pitch p (the distance OP between the tips) is increased or decreased, a trade-off relationship arises between the heat dissipation characteristics and the fluid dynamic characteristics.

[0040] From the above simulation results, it was found that levels 3, 4, and 5 have a good balance between heat dissipation characteristics and fluid dynamic characteristics, and level 4 has an especially good balance. Therefore, when configuring the heat sink 20 of embodiment 1, it has been found that it is preferable that the plurality of heat dissipating fins are arranged at a pitch p at the base end of a predetermined value within the range of 1.0 mm to 2.5 mm (a desired value set as a constant value; the same applies below) (Levels 3 to 5). Furthermore, when the inventors conducted further experiments, it has been found that it is more preferable that the heat dissipating fins are arranged at a pitch p at the base end of a predetermined value within the range of 1.8 mm to 2.2 mm. Furthermore, it has been found that it is even more preferable that the heat dissipating fins are arranged at a pitch p of 2 mm at the base end.

[0041] Similarly, it was found that the spacing OP between the tips 24 of the heat dissipation fins 22 during use is preferably maintained at a predetermined spacing within the range of 1.1 mm to 1.8 mm between the tips 24 of adjacent heat dissipation fins 22. It was also found that it is more preferable to maintain the spacing between the tips 24 of the heat dissipation fins 22 at a predetermined spacing within the range of 1.2 mm to 1.6 mm, and even more preferably around 1.47 mm.

[0042] 3. Effects of the thermoelectric conversion unit 1 according to the first embodiment In the thermoelectric conversion unit 1 according to the first embodiment, the radiator 20 is made of a metal plate and has a plurality of plate-shaped heat dissipation fins 22 formed integrally with a base 21 on a front side 26 thereof, the base 21 being bendable, and the radiator 20 is stacked on the thermoelectric circuit module 10 such that the back side 25 is in close contact with the second main surface 16 of the thermoelectric circuit module 10. The plurality of heat dissipation fins 22 are arranged at a pitch p at their base ends 23 of a predetermined value within a range of 1.0 mm to 2.5 mm. Alternatively, the thermoelectric conversion unit 1 is configured such that, when attached to the curved surface of a given heating element 110, the tips 24 of the plurality of adjacent heat dissipation fins 22 are spaced apart at a predetermined value OP within a range of 1.1 mm to 1.8 mm.

[0043] Therefore, the thermoelectric conversion unit 1 according to embodiment 1 can achieve both the heat dissipation characteristics and the fluid dynamic characteristics required for a thermoelectric conversion unit used in a moving body, making it a thermoelectric conversion unit suitable for a moving body (moving at a speed of approximately 30 to 60 km / h). This allows for efficient reuse of heat that would otherwise be wasted in the exhaust cycle of a vehicle engine (internal combustion engine), while avoiding any fluid dynamic disadvantages.

[0044] It should be noted that the numerical values ​​of the above-mentioned parameters are included in the thermoelectric conversion unit 1 according to embodiment 1 even if there are differences such as slight design differences or processing errors, as long as they are within a range that does not impair the functions and effects of embodiment 1.

[0045] [Embodiment 2] FIG. 5 is a perspective view showing a main part of a thermoelectric conversion unit 2 according to the second embodiment. The thermoelectric conversion unit 2 according to the second embodiment basically has the same configuration as the thermoelectric conversion unit 1 according to the first embodiment, but differs from the thermoelectric conversion unit 1 according to the first embodiment in the configuration of the heat dissipation fins 22a.

[0046] As shown in FIG. 5, in the thermoelectric conversion unit 2, the heat dissipation fin 22a is divided into an upstream heat dissipation fin 27 and a downstream heat dissipation fin 28 in the longitudinal direction LD of the heat dissipation fin, and a gap 29 is provided between the upstream heat dissipation fin 27 and the downstream heat dissipation fin 28. With this configuration, the air flow can be reset once by stirring it at the position of the gap 29. This makes it easier to cool the air that has become hotter downstream.

[0047] Although the heat dissipating fin 22a is divided into two parts in this example, the present invention is not limited to this and the heat dissipating fin 22a may be divided into three or more parts. The thermoelectric conversion unit 2 according to embodiment 2 has basically the same configuration as the thermoelectric conversion unit 1 according to embodiment 1, except for the configuration of the heat dissipation fins 22a, and therefore has the same effects as those of the thermoelectric conversion unit 1 according to embodiment 1.

[0048] [Embodiment 3] 6A and 6B are perspective views showing a part of the thermoelectric conversion units 3, 3' according to embodiment 3. Fig. 6(a) is a perspective view showing a part of the thermoelectric conversion unit 3 according to embodiment 3. Fig. 6(b) is a perspective view showing a part of the thermoelectric conversion unit 3' according to embodiment 3.

[0049] The thermoelectric conversion units 3, 3' according to the second embodiment basically have the same configuration as the thermoelectric conversion unit 1 according to the first embodiment, but differ from the thermoelectric conversion unit 1 according to the first embodiment in the configuration of the heat dissipation fins 22b, 22c.

[0050] As shown in Fig. 5, the heat dissipation fins 22b, 22c are formed so that the frictional resistance of air passing between adjacent heat dissipation fins 22b, 22c is greater downstream than upstream. Specifically, as shown in Fig. 6(a), the surface roughness of the downstream portion of the heat dissipation fin 22b may be greater than that of the upstream portion. Alternatively, as shown in Fig. 6(b), the upstream portion of the heat dissipation fin may be flat, while the downstream portion may have a wavy outer diameter. Generally, the air temperature on the fin surface is higher downstream than upstream, but because the heat dissipation fins of embodiment 3 have the above-mentioned configuration, the downstream portion has more opportunities to come into contact with the cooling medium than the upstream portion, allowing for efficient heat dissipation downstream, where the temperature is relatively high.

[0051] The thermoelectric conversion units 3, 3' may be configured to be divided into upstream and downstream heat dissipation fins, like the thermoelectric conversion unit 2 according to the second embodiment. The thermoelectric conversion units 3, 3' according to embodiment 3 have basically the same configuration as the thermoelectric conversion unit 1 according to embodiment 1, except for the configuration of the heat dissipation fins 22b, 22c, and therefore have the same effects as those of the thermoelectric conversion unit 1 according to embodiment 1.

[0052] [Embodiment 4] FIG. 7 is a schematic diagram shown for explaining a thermoelectric power generation system 50 according to the fourth embodiment. The fourth embodiment provides a thermoelectric power generation system that converts heat emitted from a heat generating body attached to a moving object into electrical energy.

[0053] As shown in Fig. 7, a thermoelectric power generation system 50 according to the fourth embodiment is a system including at least the thermoelectric conversion unit 1 according to the first embodiment and a power storage unit 30 that stores power output from a thermoelectric circuit module (not shown) of the thermoelectric conversion unit 1. A capacitor, a battery, or the like can be used as the power storage unit 30. The thermoelectric circuit module (not shown) and the power storage unit 30 are electrically connected by an electrical connection line 32. Note that a boost circuit, a stabilization circuit, or the like may be provided between the thermoelectric circuit module (not shown) and the power storage unit 30.

[0054] 7, reference numeral 200 denotes a vehicle, 205 denotes an engine, 210 denotes an exhaust pipe, 220 denotes a vent, and 225 denotes an exhaust port. The thermoelectric conversion unit 1 is arranged so that the longitudinal direction LD of the heat dissipation fins is approximately aligned with the direction of travel MV of the moving object. As a result, wind W flows into the thermoelectric conversion unit 1 as the moving object moves. As described above, the thermoelectric power generation system 50 uses the thermoelectric conversion unit 1 suitable for a moving body, and therefore can efficiently generate thermoelectric power without reducing fluid dynamic characteristics such as pressure loss.

[0055] Although the thermoelectric conversion unit 1 according to the first embodiment has been described as an example in which it is applied as a thermoelectric conversion unit, the thermoelectric conversion units 2, 3, and 3' according to the second and third embodiments may also be applied.

[0056] [Embodiment 5] FIG. 8 is a diagram showing an application example of the heat sink 20 according to the fifth embodiment.

[0057] The heat sink 20 according to the fifth embodiment is a heat sink that is preferably used in the thermoelectric conversion unit 1 that is attached to the curved surface 112 of the heat generating body 110 attached to the moving body 100. The heat sink 20 is also preferably used in the thermoelectric power generation system 50 according to the fourth embodiment. The heat sink 20 is stacked in close contact with the thermoelectric circuit module 10 on which the thermoelectric conversion element 11 is mounted, and together with the thermoelectric circuit module 10, constitutes the thermoelectric conversion unit 1. The heat sink 20 is made of a metal plate and has a plurality of plate-shaped heat sink fins 22 formed upright on the front side 26 integrally with the base 21. The base 21 of the heat sink 20 is bendable. The plurality of heat sink fins 22 are arranged at a pitch at the base end 23 of the heat sink 20 that is a predetermined value within a range of 1.0 mm to 2.5 mm. Alternatively, the heat sink 20 is configured such that, when the thermoelectric conversion unit 1 is attached to the curved surface 112 of a given heating element 110, the tips of the plurality of adjacent heat sink fins 22 are spaced apart at a predetermined interval within a range of 1.1 mm to 1.8 mm.

[0058] As explained using Figure 1, the heat sink 20 may be used in a process in which the thermoelectric conversion unit 1 is first assembled by combining it with the thermoelectric circuit module 10, and then the thermoelectric conversion unit 1 is attached to the heating element 110.

[0059] On the other hand, the thermoelectric circuit module 10 may be attached to the heating element 110 in advance, and the heat sink 20 may be laminated on the outer peripheral surface (second main surface 16) of the thermoelectric circuit module 10 later. For example, first, split thermoelectric circuit modules 10a and 10b are attached to an exhaust pipe 210 (heat generating element 110) as shown in Fig. 8(a), and then a heat sink 20 is attached around the thermoelectric circuit modules 10a and 10b as shown in Fig. 8(b), thereby obtaining a thermoelectric conversion unit in which the heat sink 20 is attached around the thermoelectric circuit modules 10a and 10b as shown in Fig. 8(c). Such a heat sink used as an after-installation is also included in the heat sink 20 according to the fifth embodiment.

[0060] Although the heat sink 20 has been described in accordance with the first embodiment, the concept of the fourth embodiment can also be applied to the heat sinks of the aspects shown in the second and third embodiments.

[0061] Although the present invention has been described above based on the above embodiment, the present invention is not limited to the above embodiment and can be embodied in various forms without departing from the spirit of the present invention, and for example, the following modifications are also possible.

[0062] (1) In each embodiment, the thermoelectric conversion unit 1 is attached by wrapping it around the outer periphery of the exhaust pipe 210 so as to surround it 360 degrees around the pipe axis AX. However, the present invention is not limited to this. It is also possible to attach it to a portion (for example, 180 degrees) of the outer periphery of the exhaust pipe 210 (heat generating element 110), with the remaining portion of the exhaust pipe 210 exposed.

[0063] (2) In the example of manufacturing the thermoelectric conversion unit 1 described in the first embodiment, the thermoelectric circuit module 10 and the heat sink 20, which are flat (not curved) on a plane, are joined by adhering them to each other, and then the thermoelectric conversion unit 1 is attached to the heating element 110 (see FIG. 1 ). However, the present invention is not limited to this. For example, a manufacturing method can also be used in which the thermoelectric circuit module 10 is first wrapped around the heating element 110, and then the heat sink 20 is joined by being in close contact with the outer periphery (second main surface 16) of the thermoelectric circuit module 10. The case in which the thermoelectric conversion unit 1 is ultimately constructed through such a manufacturing process is also equivalent to the construction of the thermoelectric conversion unit 1 of the present invention.

[0064] (3) In each embodiment, the heat dissipation fins 22 have been described assuming a flat plate shape. However, the present invention is not limited to this. The heat dissipation fins 22 do not need to be strictly flat, and as long as they achieve the functions and effects of the present invention, slightly curled heat dissipation fins, tapered heat dissipation fins whose tip is slightly thinner than their base end, and stepped heat dissipation fins that have a slight step halfway up from the base end 23 to the tip end 24 are also included in the heat dissipation fins 22 of the present invention. [Explanation of symbols]

[0065] 1, 2, 3... thermoelectric conversion unit, 10, 10a, 10b... thermoelectric circuit module, 11... thermoelectric conversion element, 15... first main surface (of thermoelectric circuit module), 16... second main surface (of thermoelectric circuit module), 20... heat sink, 21... base, 22, 22a, 22b, 22c... heat dissipation fin, 23... base end (of heat dissipation fin), 24... tip (of heat dissipation fin), 25... back surface (of heat sink), 26... front side (of heat sink), 27... upstream heat dissipation fin, 28... downstream heat dissipation fin, 29... gap, 30... power storage section, 32... electrical connection wire, 50... thermoelectric power generation system, 100... mobile object, 110... heating element, 112... curved surface (of heating element), 200... vehicle, 205... engine, 210... exhaust pipe, 220... silencer, 225... exhaust port

Claims

1. A thermoelectric conversion unit attached to a curved surface of a heating element, a thermoelectric circuit module on which a thermoelectric conversion element is mounted, the thermoelectric circuit module having a first main surface and a second main surface opposite to the first main surface that are bendable; a heat sink made of a metal plate material, having a plurality of plate-shaped heat dissipation fins formed integrally with a base on a front side thereof, the base being bendable, and the heat sink being stacked on the thermoelectric circuit module such that the back side of the heat sink is in close contact with the second main surface of the thermoelectric circuit module, The thermoelectric conversion unit is attached to the heat generating body attached to the moving body, and is arranged so that the longitudinal direction of the heat dissipation fins is substantially aligned with the direction of travel of the moving body, and is configured so that wind acting as a refrigerant accompanying the movement of the moving body enters between adjacent heat dissipation fins, The heat sink is It is made of pure aluminum, The thickness of the base is 5 mm and the height of the heat dissipation fin is 25 mm. When a heat quantity of 2000 W is applied to the entire rear surface of the radiator having a width of 400 mm and a depth of 200 mm, the radiator is configured to be able to flow air at 60°C as the refrigerant at 60 km / h along the longitudinal direction of the radiating fins, The plurality of heat dissipation fins are arranged at a pitch at the base end of the fins that is a predetermined value within a range of 1.0 mm to 2.5 mm. A thermoelectric conversion unit characterized by:

2. A thermoelectric conversion unit attached to a curved surface of a heating element, a thermoelectric circuit module on which a thermoelectric conversion element is mounted, the thermoelectric circuit module having a first main surface and a second main surface opposite to the first main surface that are bendable; a heat sink made of a metal plate material, having a plurality of plate-shaped heat dissipation fins formed integrally with a base on a front side thereof, the base being bendable, and the heat sink being stacked on the thermoelectric circuit module such that the back side of the heat sink is in close contact with the second main surface of the thermoelectric circuit module, The thermoelectric conversion unit is attached to the heat generating body attached to the moving body, and is arranged so that the longitudinal direction of the heat dissipation fins is substantially aligned with the direction of travel of the moving body, and is configured so that wind acting as a refrigerant accompanying the movement of the moving body enters between adjacent heat dissipation fins, The heat sink is It is made of pure aluminum, The thickness of the base is 5 mm and the height of the heat dissipation fin is 25 mm. When a heat quantity of 2000 W is applied to the entire rear surface of the radiator having a width of 400 mm and a depth of 200 mm, the radiator is configured to be able to flow air at 60°C as the refrigerant at 60 km / h along the longitudinal direction of the radiating fins, The thermoelectric conversion unit is configured such that, when attached to the curved surface of a given heat generating body, the tips of the plurality of heat dissipation fins adjacent to each other are spaced apart at a predetermined distance within a range of 1.1 mm to 1.8 mm. A thermoelectric conversion unit characterized by:

3. In the thermoelectric conversion unit according to claim 1 or 2, A thermoelectric conversion unit characterized in that the heat dissipation fins are divided into upstream heat dissipation fins and downstream heat dissipation fins in the longitudinal direction of the heat dissipation fins, and a gap is provided between the upstream heat dissipation fins and the downstream heat dissipation fins.

4. The thermoelectric conversion unit according to any one of claims 1 to 3, The thermoelectric conversion unit is characterized in that the heat dissipation fins are formed so that frictional resistance of air passing between adjacent heat dissipation fins is greater downstream than upstream.

5. A thermoelectric power generation system that converts heat emitted from a heat generating body associated with a moving object into electrical energy, A thermoelectric conversion unit according to any one of claims 1 to 4; a power storage unit that stores the power output from the thermoelectric circuit module of the thermoelectric conversion unit.

6. A radiator used in a thermoelectric conversion unit attached to a curved surface of a heat generating body attached to a moving body, the heat sink is stacked in close contact with a thermoelectric circuit module on which a thermoelectric conversion element is mounted, and together with the thermoelectric circuit module constitutes a thermoelectric conversion unit; The heat sink is made of a metal plate and has a plurality of plate-shaped heat sink fins formed integrally with a base on the front side thereof, The base of the heat sink is bendable, When the thermoelectric conversion unit is attached to the heat generating body, the longitudinal direction of the heat dissipation fins is arranged to substantially coincide with the direction of movement of the moving body, and wind acting as a refrigerant accompanying the movement of the moving body enters between adjacent heat dissipation fins, The heat sink is It is made of pure aluminum, The thickness of the base is 5 mm and the height of the heat dissipation fin is 25 mm. When a heat quantity of 2000 W is applied to the entire rear surface of the radiator, which has a width of 400 mm and a depth of 200 mm, the radiator is configured so that air at 60°C as the refrigerant can flow at 60 km / h along the longitudinal direction of the radiating fins, The plurality of heat dissipation fins are arranged at a pitch at the base end of the fins that is a predetermined value within a range of 1.0 mm to 2.5 mm. A heat sink characterized by:

7. A radiator used in a thermoelectric conversion unit attached to a curved surface of a heat generating body attached to a moving body, the heat sink is stacked in close contact with a thermoelectric circuit module on which a thermoelectric conversion element is mounted, and together with the thermoelectric circuit module constitutes a thermoelectric conversion unit; The heat sink is made of a metal plate and has a plurality of plate-shaped heat sink fins formed integrally with a base on the front side thereof, The base of the heat sink is bendable, When the thermoelectric conversion unit is attached to the heat generating body, the longitudinal direction of the heat dissipation fins is arranged to substantially coincide with the direction of movement of the moving body, and wind acting as a refrigerant accompanying the movement of the moving body enters between adjacent heat dissipation fins, The heat sink is It is made of pure aluminum, The thickness of the base is 5 mm and the height of the heat dissipation fin is 25 mm. When a heat quantity of 2000 W is applied to the entire rear surface of the radiator, which has a width of 400 mm and a depth of 200 mm, the radiator is configured so that air at 60°C as the refrigerant can flow at 60 km / h along the longitudinal direction of the radiating fins, The heat sink is configured so that, when the thermoelectric conversion unit is attached to the curved surface of a given heat generating body, the tips of the plurality of heat dissipation fins adjacent to each other are spaced apart at a predetermined distance within a range of 1.1 mm to 1.8 mm. A heat sink characterized by:

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