JP2013098494A - Thermal power generation system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technique for improving power generation efficiency of a thermal power generation system.SOLUTION: A thermal power generation system 1 includes a thermoelectric conversion module 10 and a heat exchanging device 20. The thermoelectric conversion module 10 has first and second surfaces, and generates electric power by generating a temperature difference between the first and second surfaces. The heat exchanging device 20 includes a component adjoining the first surface. A plurality of through holes extending respectively in predetermined directions are formed in the component. The heat exchanging device 20 is so configured that a heating medium flows in the respective through holes in the same direction.

Description

  Embodiments described herein relate generally to a thermoelectric power generation system.

  As described in Patent Document 1, it is considered to use a thermoelectric conversion module in order to recover thermal energy generated in various devices and industrial plants. For example, thermal energy can be recovered as electrical energy by installing a plurality of thermoelectric conversion modules between a pair of pipes, flowing hot water through one pipe, and flowing cold water through the other pipe.

JP 2009-247049 A

  An object of the present invention is to provide a technique capable of improving the power generation efficiency of a thermoelectric power generation system.

  The thermoelectric generation system of the embodiment includes a thermoelectric conversion module and a heat exchange device. The thermoelectric conversion module has first and second surfaces, and generates power by generating a temperature difference between the first and second surfaces. The heat exchange device includes a component adjacent to the first surface. The component is provided with a plurality of through holes each extending in a specific direction. The heat exchange device is configured such that the heat medium flows through each of the through holes in the same direction.

1 is a cross-sectional view schematically showing a thermoelectric generation system according to a first embodiment. Sectional drawing which shows schematically the thermoelectric conversion module which the thermoelectric generation system of FIG. 1 contains. FIG. 2 is a cross-sectional view schematically showing a heat exchange device included in the thermoelectric generator system of FIG. 1. The other sectional view showing roughly the heat exchange device which the thermoelectric generator system of Drawing 1 contains. Sectional drawing which shows schematically the thermoelectric power generation system which concerns on one modification. Sectional drawing which shows schematically the thermoelectric power generation system which concerns on another modification. Furthermore, sectional drawing which shows schematically the thermoelectric power generation system which concerns on another modification. Furthermore, sectional drawing which shows schematically the thermoelectric power generation system which concerns on another modification. The one sectional view showing roughly the heat exchange device which the thermoelectric generator system concerning a 2nd embodiment contains. The other sectional view showing roughly the heat exchanging device which the thermoelectric generator system concerning a 2nd embodiment contains.

  Hereinafter, embodiments will be described in detail with reference to the drawings. In addition, the same referential mark is attached | subjected to the component which exhibits the same or similar function through all drawings, and the overlapping description is abbreviate | omitted.

First, the first embodiment will be described with reference to FIGS.
A thermoelectric generation system 1 shown in FIG. 1 includes a thermoelectric conversion module 10, a first heat exchange device 20, and a second heat exchange device 30. In the drawing, the X direction is a direction parallel to the main surface of the thermoelectric conversion module 10. The Y direction is a direction parallel to the main surface of the thermoelectric conversion module 10 and perpendicular to the X direction. The Z direction is a direction perpendicular to the X direction and the Y direction, and corresponds to the thickness direction of the thermoelectric conversion module 10.

  In the example shown in FIG. 1, a plurality of thermoelectric conversion modules 10 are arranged in the X direction between the first heat exchange device 20 and the second heat exchange device 30. Only one thermoelectric conversion module 10 may be installed between the first heat exchange device 20 and the second heat exchange device 30.

  As shown in FIG. 2, the thermoelectric conversion module 10 has a first surface F1 and a second surface F2. The thermoelectric conversion module 10 generates power by generating a temperature difference between the first surface F1 and the second surface F2. Specifically, when the thermoelectric conversion module 10 causes a temperature difference between the first surface F1 and the second surface F2, an electromotive force is generated by the Seebeck effect.

  As shown in FIG. 2, the thermoelectric conversion module 10 includes a first insulating layer 110a and a second insulating layer 110b. The insulating layers 110a and 110b are arranged in the Z direction so that their main surfaces are parallel to the X direction and the Y direction.

  The insulating layers 110a and 110b are made of an inorganic insulator such as alumina, for example. The insulating layers 110a and 110b may have a single layer structure or a multilayer structure. When a multilayer structure is employed for the insulating layer 110a, one or more of the other layers may be conductive as long as the layer closest to the insulating layer 110b is insulative. Similarly, when a multilayer structure is employed for the insulating layer 110b, one or more of the other layers may be conductive as long as the layer closest to the insulating layer 110a is insulating.

  A first portion 120a and a second portion 120b are interposed between the insulating layers 110a and 110b. Each of the first portion 120a and the second portion 120b has, for example, a shape extending in the Y direction. The first portion 120a and the second portion 120b are arranged apart from each other.

  In the example shown in FIG. 2, the first portion 120a and the second portion 120b are arranged in the X direction, but the arrangement direction may not be the X direction. For example, the first portion 120a and the second portion 120b may be alternately arranged in the Y direction. In the example shown in FIG. 2, each thermoelectric conversion module 10 includes a plurality of first portions 120a and second portions 120. However, each thermoelectric conversion module 10 includes the first portion 120a and the second portion 120b. Only one of each may be included.

  The first portion 120a and the second portion 120b are made of different materials. As a material of the first portion 120a and the second portion 120b, a metal or a semiconductor can be used. For example, one of the first portion 120a and the second portion 120b is made of a p-type semiconductor, and the other of the first portion 120a and the second portion 120b is made of an n-type semiconductor. In this case, as the material of the first portion 120a and the second portion 120b, for example, a material containing bismuth and tellurium such as bismuth telluride and impurities such as selenium and antimony can be used. . When such a material is used, particularly excellent power generation efficiency can be achieved, for example, in power generation using heat of 220 ° C. or lower, particularly 150 ° C. or lower.

  A first conductor layer 130a is interposed between the insulating layer 110a and the first portion 120a and the second portion 120b. Each of the conductor layers 130a has a band shape extending in the Y direction. These conductor layers 130a are arranged in the X direction corresponding to a set of one first portion 120a and one second portion 120b. Each conductor layer 130a electrically connects the first portion 120a and the second portion 120b included in the above set to each other.

  A second conductor layer 130b is interposed between the insulating layer 110b and the first portion 120a and the second portion 120b. Each of the conductor layers 130b has a band shape extending in the Y direction. These conductor layers 130b are arranged in the X direction corresponding to the above set. Each conductor layer 130b electrically connects a first portion 120a included in one of two adjacent sets and a second portion 120b included in the other set.

  The conductor layers 130a and 130b are made of, for example, a single metal or an alloy. As a material of the conductor layers 130a and 130b, for example, a metal material such as solder can be used. Each of the conductor layers 130a and 130b may have a single layer structure or a multilayer structure. When adopting a multilayer structure for the conductor layer 130a or 130b, for example, a layer made of copper, nickel, or an alloy containing at least one of them may be formed, and a layer made of solder may be provided thereon.

  In addition, when each thermoelectric conversion module 10 includes only one each of the first portion 120a and the second portion 120b, one of the conductor layers 130a and 130b can be omitted.

  An insulating layer 140 is interposed between the first portion 120a and the second portion 120b. The insulating layer 140 is made of, for example, an inorganic insulator or an organic insulator. The insulating layer 140 can be omitted.

  As shown in FIG. 1, the first heat exchange device 20 is adjacent to the thermoelectric conversion module 10. The first heat exchange device 20 mediates heat exchange between the first heat medium and the first surface F1 shown in FIG. Here, the first heat medium is a fluid flowing in the X direction, for example, a liquid or a gas.

  The heat exchange device 20 includes a first component 210 shown in FIGS. 3 and 4. The component 210 is adjacent to the first surface F1 shown in FIG.

  The component 210 constitutes, for example, a part of a flow path for flowing the first heat medium. The component 210 may be installed in a flow path (not shown) through which the first heat medium flows.

  The component 210 is made of, for example, a metal or a non-metallic material. As the metal material, for example, a single metal such as aluminum, copper and iron or an alloy containing at least one of them can be used. Stainless steel such as special purpose stainless steel (SUS) may be used as the alloy. As the non-metallic material, for example, silicon can be used.

  The component 210 is provided with a plurality of first through holes TH each extending in the first direction. The heat exchange device 20 is configured such that the first heat medium flows in the same direction through each of the through holes TH. Typically, the first direction is parallel to the flow direction of the first heat medium upstream and downstream of the component 210. Here, the first direction is a direction parallel to the X direction.

  The component 210 may be provided with through holes TH having the same diameter or through holes TH having different diameters. From the viewpoint of heat exchange efficiency, the component 210 is preferably provided with through holes TH having the same diameter.

  The diameter of the through hole TH is, for example, 10 mm or less, and preferably 5 mm or less. When the diameter of the through hole TH is increased, the efficiency of heat exchange decreases. Further, the diameter of the through hole TH is, for example, 1 mm or more, preferably 3 mm or more. When the diameter of the through hole TH is reduced, the pressure loss of the first heat medium is increased.

  The ratio of the length to the diameter of the through hole TH is, for example, 2 or more. Increasing this ratio increases the surface area available for heat exchange. Further, when this ratio is increased, the turbulent flow of the first heat medium can be suppressed, so that the pressure loss of the first heat medium can be reduced.

  In the cross section perpendicular to the length direction of the through hole TH, here, in the cross section perpendicular to the X direction, the ratio of the total area of the through holes TH to the area of the component 210 is, for example, 30% or more. Increasing this ratio increases the surface area available for heat exchange. Moreover, this ratio is 60% or less, for example. When this ratio is reduced, the strength of the component 210 is reduced.

  In the cross section perpendicular to the length direction of the through hole TH, each through hole TH is circular. The shape of the through hole TH in this cross section may not be circular. For example, in this cross section, the through hole TH may be a polygon such as a triangle, a quadrangle, and a hexagon.

  In the cross section perpendicular to the length direction of the through holes TH, the through holes TH may be arranged regularly or irregularly. In the former case, the through holes TH may be arranged in a lattice shape such as a triangular lattice and a square lattice.

  The component 210 is obtained, for example, by forming a plurality of through holes in the block. Alternatively, the component 210 is obtained by laminating a plurality of thin plates each provided with a plurality of through holes. A structure provided with a plurality of through holes can be obtained by using a chemical processing process such as photo etching and electroforming, or a machining process such as cutting, pressing, electric discharge, and laser processing using a drill. Can do.

  As shown in FIG. 1, the second heat exchange device 30 is adjacent to the thermoelectric conversion module 10. The second heat conversion device 30 mediates heat exchange between the second heat medium and the second surface F2 shown in FIG. Here, the second heat medium is, for example, a liquid or a gas, typically a gas. The temperature of the second heat medium is different from the temperature of the first heat medium. Here, as an example, the temperature of the second heat medium is lower than the temperature of the first heat medium.

  The second heat exchange device 30 includes a plurality of fins. The second heat exchange device 30 is made of, for example, a metal material. As the metal material, for example, a single metal or an alloy such as copper and aluminum can be used.

  This thermoelectric generator system 1 includes a plurality of thermoelectric conversion modules 10 as described above. These thermoelectric conversion modules 10 are connected in series or in parallel. The number and electrical connection of the thermoelectric conversion modules 10 are appropriately selected according to the use of power output from the thermoelectric generator system 1.

  The thermoelectric generator system 1 outputs a direct current. Therefore, typically, the thermoelectric generation system 1 is combined with an inverter, a controller, a power conditioner, a battery, a capacitor, and the like to convert a direct current into an alternating current. Of course, you may use the direct current which the thermoelectric power generation system 1 outputs, without converting into alternating current.

  As described above, the thermoelectric generator system 1 includes the first heat exchange device 20. The first heat exchange device 20 includes a component 210 provided with a plurality of through holes TH, and the first surface F1 of the thermoelectric conversion module 10 and the first heat medium that the component 210 circulates in the through holes TH. It mediates heat exchange with. Therefore, for example, high heat exchange efficiency can be achieved as compared with the case where one pipe is used instead of the first heat exchange device 20. Therefore, this thermoelectric generation system 1 can achieve high power generation efficiency. In particular, the thermoelectric generator system 1 is extremely useful when the temperature of the first heat medium is relatively low.

  Various modifications can be made to this thermoelectric generation system. A modification of the first embodiment will be described with reference to FIGS.

  In the modification shown in FIG. 5, the first heat exchange device 20 is configured by a plurality of components 210. These components 210 are arranged in series along the flow direction of the first heat medium, here the X direction, in the flow path through which the first heat medium flows. By adopting this structure, it is possible to minimize the pressure loss of the first heat medium resulting from clogging of part of the through hole TH.

  When the first heat exchanging device 20 is configured with a plurality of components 210, the plurality of components 210 can be arranged for one thermoelectric conversion module 10 as shown in FIG. 5. Alternatively, one component 210 may be installed for one thermoelectric conversion module 10.

  In the modification shown in FIG. 6, the first heat exchange device 20 is constituted by a component 210 and a heat insulating material 220. The heat insulating material 220 faces the first surface F1 with the component 210 interposed therebetween.

  The heat insulating material 220 is, for example, a coating containing an inorganic material. As the inorganic material, for example, silica or alumina powder can be used. The coating can further include other components such as an adhesive.

  When the heat insulating material 220 is provided, it is possible to suppress the thermal energy of the first heat medium from being dissipated to the outside of the thermoelectric generation system 1. Therefore, higher power generation efficiency can be achieved.

  In the modification shown in FIG. 7, the second heat exchange device 30 has the same structure as the first heat exchange device 20 described with reference to FIGS. 3 and 4. That is, the second heat exchange device 30 includes a second component adjacent to the second surface F2. The second component is provided with a plurality of second through holes each extending in the second direction. The second heat exchange device 30 is configured such that the second heat medium flows in the same direction through each of the second through holes. Here, the second direction is parallel to the first direction, but the second direction and the first direction may cross each other.

  When the structure of FIG. 7 is adopted, in addition to achieving high heat exchange efficiency in the first heat exchange device 20, high heat exchange efficiency can also be achieved in the second heat exchange device 20. Therefore, higher power generation efficiency can be achieved.

  In the modification shown in FIG. 8, the first heat conversion device 20 has the same structure as the second heat exchange device 20 described with reference to FIG. 1.

  In the modification shown in FIG. 8, the second heat exchange device 30 has the same structure as the first heat exchange device 20 described with reference to FIGS. 3 and 4. That is, the second heat exchange device 30 includes a second component adjacent to the second surface F2. The second component is provided with a plurality of second through holes each extending in the second direction. The second heat exchange device 30 is configured such that the second heat medium flows in the same direction through each of the second through holes.

  When the structure of FIG. 8 is adopted, high heat exchange efficiency can be achieved in the second heat exchange device 20. Therefore, also in this case, high power generation efficiency can be achieved.

  The structure described with reference to FIG. 5 and the structure described with reference to FIG. 6 can be combined with each other. That is, you may provide the heat insulating material 220 demonstrated referring FIG. 6 on each component 210 shown in FIG.

  The structure described with reference to FIG. 7 may be combined with at least one of the structure described with reference to FIG. 5 and the structure described with reference to FIG. In this case, at least one of the structure described with reference to FIG. 5 and the structure described with reference to FIG. 6 may be applied to one of the heat exchange devices 20 and 30. Alternatively, at least one of the structure described with reference to FIG. 5 and the structure described with reference to FIG. 6 may be applied to both of the heat exchange devices 20 and 30.

  The structure described with reference to FIG. 8 may be combined with at least one of the structure described with reference to FIG. 5 and the structure described with reference to FIG. That is, at least one of the structure described with reference to FIG. 5 and the structure described with reference to FIG. 6 may be applied to the heat exchange device 30.

Next, a second embodiment will be described with reference to FIGS. 9 and 10.
The thermoelectric generator system according to the second embodiment is the same as the thermoelectric generator system 1 according to the first embodiment except that the following configuration is adopted.

  That is, in the thermoelectric generator system according to the second embodiment, as shown in FIGS. 9 and 10, both ends of a part of the through holes TH are sealed with plugs 230a and 230b, and the heat storage material 240 is filled in them. Yes. The heat storage material 240 plays a role of suppressing a change in the power generation amount of the thermoelectric generation system 1 due to a temperature change of the first heat medium.

  As the heat storage material 240, for example, a sensible heat storage material having a larger specific heat than that of the component 210 can be used. As the sensible heat storage material, for example, mineral oil can be used.

  Alternatively, a latent heat storage material may be used as the heat storage material 240. It is preferable to use a material that causes a phase change from a liquid to a solid at a temperature lower than the average temperature of the first heat medium, for example, 10 ° C. to 20 ° C. lower than the average temperature of the first heat medium. As the latent heat storage material, for example, magnesium chloride hexahydrate or erythritol can be used. The latent heat storage material may be used in combination with the sensible heat storage material.

  When the latent heat storage material is used, if the temperature T1 of the first heat medium is equal to or higher than the transition temperature T2 of the latent heat storage material, the thermoelectric generator system 1 generates power using the heat energy of the first heat medium. When the temperature T1 of the first heat medium is lower than the transition temperature T2 of the latent heat storage material, the thermoelectric generation system 1 generates power using the thermal energy stored in the latent heat storage material. In this way, a change in the amount of power generated by the thermoelectric generator system 1 due to a temperature change in the first heat medium is suppressed.

  When this configuration is adopted, the heat stored in the heat storage material 240 is directly transmitted to the component 210. Therefore, the energy stored in the heat storage material 240 can be efficiently used for power generation.

  The technology described in the second embodiment may be applied to the thermoelectric generation system 1 according to the first embodiment. Moreover, you may apply the technique demonstrated in 2nd Embodiment to the thermoelectric power generation system which concerns on said modification.

  The above-described thermoelectric power generation system can be used, for example, for power generation from waste heat generated in a garbage incineration plant, a cleaning plant, or an oil refinery. Specifically, as one of the first and second heat media, water used for cooling the incinerator, water discharged by the steam turbine used for recovering exhaust heat from the incinerator, or crude oil refining. Use the water used to cool the fractionated refined oil. And as the other of said 1st and 2nd heat medium, cooler cooling water is used, or gas, such as air, is used. In this way, heat energy generated in various devices and industrial plants can be recovered as electric energy. In addition, the electric power generated in this way can be used for, for example, lighting in the field or a ventilation fan.

  DESCRIPTION OF SYMBOLS 1 ... Thermoelectric power generation system, 10 ... Thermoelectric conversion module, 20 ... 1st heat exchange apparatus, 30 ... 2nd heat exchange apparatus, 110a ... 1st insulating layer, 110b ... 2nd insulating layer, 120a ... 1st part, 120b ... Second part, 130a ... first conductor layer, 130b ... second conductor layer, 140 ... insulating layer, 210 ... first component, 220 ... heat insulating material, 230a ... plug, 230b ... plug, 240 ... heat storage material, F1 ... first 1st surface, F2 ... 2nd surface, TH ... 1st through-hole.

Claims (10)

A thermoelectric conversion module that has first and second surfaces and generates power by generating a temperature difference between the first and second surfaces;
The first part includes a first part adjacent to the first surface, and the first part is provided with a plurality of first through holes each extending in a first direction, and a first heat medium is provided in the first through holes. A thermoelectric generator system comprising: a first heat exchange device configured to flow in the same direction.   The thermoelectric power generation system according to claim 1, wherein each of the plurality of first through holes has a diameter of 10 mm or less.   The first heat exchange device further includes one or more holes each extending in the first direction and sealed at both ends, and each of the one or more holes is filled with a heat storage material. The thermoelectric power generation system according to claim 1 or 2.   The thermoelectric generator system according to claim 3, wherein the heat storage material is a latent heat storage material.   The thermoelectric power generation system according to any one of claims 1 to 4, wherein the first heat exchange device further includes a heat insulating material facing the first surface with the first component interposed therebetween.   The thermoelectric generation system according to claim 5, wherein the heat insulating material is a coating including an inorganic material provided on the first component.   The thermoelectric generation system according to any one of claims 1 to 6, wherein each of the plurality of first through holes has a ratio of a length to a diameter of 2 or more.   The thermoelectric conversion module includes: a first insulating layer adjacent to the first heat exchange device; a second insulating layer facing the first heat exchange device with the first insulating layer interposed therebetween; First and second portions spaced apart from each other between the second insulating layers, and a conductor layer interposed between the first and second portions and the first or second insulating layer, Each of the first and second portions includes bismuth and tellurium, one of the first and second portions is a p-type semiconductor, and one of the first and second portions is an n-type semiconductor. 8. The thermoelectric generator system according to any one of items 7.   The thermoelectric power generation system according to any one of claims 1 to 8, wherein the first component is made of a material selected from the group consisting of aluminum, copper, iron, and stainless steel.   A second part adjacent to the second surface, wherein the second part is provided with a plurality of second through holes each extending in a second direction, and a second heat medium is provided in the plurality of second through holes. The thermoelectric generator system according to any one of claims 1 to 9, further comprising a second heat exchange device configured to flow in the same direction.

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