WO2011036854A1

WO2011036854A1 - Heat exchanger

Info

Publication number: WO2011036854A1
Application number: PCT/JP2010/005610
Authority: WO
Inventors: 寺木潤一
Original assignee: ダイキン工業株式会社
Priority date: 2009-09-25
Filing date: 2010-09-14
Publication date: 2011-03-31
Also published as: JP2011071338A; JP4770973B2

Abstract

A thermoelectric element (22) is provided with a first insulating substrate (A) and a second insulating substrate (B) which extend in the form of strips, one on top of the other. The thermoelectric element (22) is also provided with: a plurality of heat-absorbing side electrodes (2) formed on the upper surface of the first insulating substrate (A); a plurality of heat-emitting side electrodes (3) formed on both surfaces of the first insulating substrate (A) and connected by through-holes (7); and p-type thermoelectric material (5) and n-type thermoelectric material (6) formed as thin films so as to respectively contact the heat-absorbing side electrodes (2) and heat-emitting side electrodes (3). The thermoelectric element (22) is further provided with a plurality of heat-absorbing side electrodes (8) which are formed on both surfaces of the second insulating substrate (B) and which are connected by the through-holes (7) and have undersurfaces connected with the heat-absorbing side electrodes (2).

Description

Heat exchanger

The present invention relates to a heat exchanger.

Conventionally, a so-called thermoelectric element type heat exchanger in which heat is exchanged between fluids using a thermoelectric element is known. For example, PTL 1 discloses a Peltier heat pump that is a thermoelectric element type heat exchanger. Non-Patent Document 1 discloses a heat exchanger in which Peltier elements are arranged so as to sandwich both sides of a microchannel. In this heat exchanger, when the thermoelectric element is energized, for example, the microchannel side becomes the heat dissipation side and the fin group side becomes the heat absorption side. And the liquid which flows through a microchannel is heated, and the air which distribute | circulates a fin group is cooled.

JP 2008-106958 A

However, the above-described heat exchanger has a problem that it is difficult to produce a thermoelectric element having a size necessary for ensuring heat exchange performance. FIG. 10A is a longitudinal sectional view showing a configuration of a conventional thermoelectric element. As shown in FIG. 10A, the thermoelectric element (50) includes an electrode (51) between a first insulating substrate (A) and a second insulating substrate (B) made of ceramic or the like. The p-type and n-type thermoelectric materials (5, 6) are sandwiched. When a current is passed through the thermoelectric element (50), a temperature difference is generated between the first and second insulating substrates (A, B).

For example, when the first insulating substrate (A) is on the heat dissipation side and the second insulating substrate (B) is on the heat absorbing side, as shown in FIG. As the insulating substrate (A) expands, the second insulating substrate (B) deforms so as to contract. Therefore, thermal stress is generated at the end faces of the p-type thermoelectric material (5) and the n-type thermoelectric material (6), and the joint between the electrode (51) and the p-type and n-type thermoelectric material (5, 6) is destroyed. There is a risk that. In addition, since the thermal stress increases at the end in the longitudinal direction as the size of the thermoelectric element (50) increases, it becomes difficult to manufacture the thermoelectric element (50) extending in a strip shape.

In order to reduce the thermal stress, the first and second insulating substrates (A, B) may be changed to a flexible material such as polyimide, or the first and second insulating substrates (A, B). Although measures such as eliminating itself may be considered, it is not preferable because the planar accuracy and strength of the thermoelectric element (50) are reduced. Furthermore, when the thermoelectric element (50) is manufactured, the solder is melted in the furnace in order to join the electrode (51) and the p-type and n-type thermoelectric materials (5, 6) with the solder. There is a problem that a large-sized thermoelectric element (50) cannot be produced because the size in the furnace is limited.

The present invention has been made in view of such a point, and an object thereof is to make it possible to easily produce a thermoelectric element having a size necessary for ensuring heat exchange performance.

In order to achieve the above-described object, the present invention configures a heat exchanger using a thermoelectric element in which a strip electrode array extending in an in-plane direction of an insulating substrate is formed.

Specifically, the present invention provides a thermoelectric element (22) and a first fluid that is disposed so as to sandwich the thermoelectric element (22) and performs heat exchange between the thermoelectric element (22) and a target fluid. For the heat exchanger provided with the flow path member (21) and the second fluid flow path member (25), the following solution was taken.

That is, in the first invention, the thermoelectric element (22)
A first insulating substrate (A) and a second insulating substrate (B) that are stacked on each other and extend in a strip shape along the longitudinal direction of the first fluid channel member (21) and the second fluid channel member (25). )When,
A plurality of first electrodes formed on the surface of the first insulating substrate (A) on the second insulating substrate (B) side and spaced apart from each other in the longitudinal direction of the first insulating substrate (A). (2) and
The first insulating substrate (A) is formed on both surfaces of the first insulating substrate (A) so as to be adjacent to the first electrodes (2) and spaced apart from the first electrode (2). A plurality of second electrodes (3) whose both surfaces are connected by through holes (7) extending in the thickness direction of
Through-holes formed on both surfaces of the second insulating substrate (B) at intervals in the longitudinal direction of the second insulating substrate (B) and extending in the thickness direction of the second insulating substrate (B) A plurality of third electrodes (8) having both surfaces connected by holes (7) and having a surface on the first insulating substrate (A) side connected to the first electrode (2);
On the surface of the first insulating substrate (A) on the second insulating substrate (B) side, the first electrode (2) and the second electrode (3) adjacent to the first electrode (2) The first conductive thermoelectric material (5) and the second conductive thermoelectric material (6) formed in a thin film so as to be in contact with each other are provided.

In the first invention, when a current is passed in the in-plane direction of the first conductive type thermoelectric material (5) and the second conductive type thermoelectric material (6) formed into a thin film, the first electrode (2) and the first conductive type At the interface between the thermoelectric material (5) and the second conductivity type thermoelectric material (6) and at the interface between the second electrode (3) and the first conductivity type thermoelectric material (5) and the second conductivity type thermoelectric material (6) The Peltier effect generates heat and heat. That is, a temperature difference corresponding to both ends of the first conductivity type thermoelectric material (5) and the second conductivity type thermoelectric material (6). As a result, for example, the first electrode (2) becomes a heat absorption side electrode, and the second electrode (3) becomes a heat dissipation side electrode.

In the first insulating substrate (A), the surface on the second insulating substrate (B) side of the second electrode (3) and the opposite surface are connected by the through hole (7). Heat is radiated from the surface side of the first insulating substrate (A).

On the other hand, since the third electrode (8) formed on the surface of the second insulating substrate (B) on the first insulating substrate (A) side is connected to the first electrode (2), the third electrode (8) is the endothermic electrode. In the second insulating substrate (B), the surface on the first insulating substrate (A) side of the third electrode (8) and the surface opposite thereto are connected by the through hole (7). Heat is absorbed from the surface side of the second insulating substrate (B).

Thereby, a heat exchanger using a thermoelectric element (22) of a type that radiates heat from one surface of the first insulating substrate (A) and absorbs heat from one surface of the second insulating substrate (B) is realized. The That is, in the first insulating substrate (A) and the second insulating substrate (B), heat absorption and heat dissipation occur on the substrate surface side excluding the opposing surfaces.

When heat absorption and heat dissipation occur, a temperature difference occurs between the first insulating substrate (A) and the second insulating substrate (B), and thermal deformation occurs such that the heat absorption side contracts and the heat dissipation side expands. A neutral surface is formed between the first insulating substrate (A) and the second insulating substrate (B), and thermal deformation is minimized. In order to form a first conductive thermoelectric material (5) and a second conductive thermoelectric material (6) in a thin film only between the first insulating substrate (A) and the second insulating substrate (B), The thermal stress acting on the conductive thermoelectric material (5) and the second conductive thermoelectric material (6) is small, and even if the size of the thermoelectric element (22) is increased, the increase in thermal stress is suppressed.

Moreover, since a current is caused to flow in the in-plane direction of the first conductive type thermoelectric material (5) and the second conductive type thermoelectric material (6) formed into a thin film to cause a temperature difference, the distance from the low temperature side to the high temperature side is The temperature difference increases. In addition, since the first conductive thermoelectric material (5) and the second conductive thermoelectric material (6) are provided between the first insulating substrate (A) and the second insulating substrate (B), Compared with the case where the first conductive thermoelectric material (5) and the second conductive thermoelectric material (6) are provided on the surface, the first conductive thermoelectric material (5) and the second conductive thermoelectric material even when bending force is applied. The tensile stress or compressive stress acting on (6) is reduced, making it difficult to break.

In addition, for example, in a so-called roll-to-roll method, a circuit pattern is printed on a flexible substrate wound in a roll shape, and is bonded to a sealing film wound in another roll shape and then wound again in a roll shape. A thermoelectric element (22) can be produced and the manufacturing cost can be greatly reduced.

According to a second invention, in the first invention,
One of the first and second fluid flow paths (21, 25) is composed of a refrigerant pipe (21) through which a refrigerant as a target fluid flows, and the other is a group of fins that exchange heat with air as a target fluid ( 25).

In the second invention, one of the first and second fluid flow paths (21, 25) is constituted by a refrigerant pipe (21) through which a refrigerant as a target fluid flows. The other is composed of a fin group (25) that exchanges heat with air as the target fluid. With this configuration, for example, when the surface on the refrigerant tube (21) side becomes a heating surface (heat dissipating surface) and the surface on the fin group (25) side becomes a cooling surface (heat absorbing surface), the refrigerant tube (21) While the refrigerant flowing through is heated, the air flowing through the fin group (25) is cooled. And this cooled air is sent to the utilization side, and the heat exchanger using a thermoelectric element (22) is implement | achieved.

According to a third invention, in the second invention,
The thermoelectric element (22) is provided in a pair so as to sandwich the refrigerant pipe (21),
The fin group (25) is provided on the surface of each thermoelectric element (22) opposite to the refrigerant pipe (21) side.

In the third invention, the refrigerant pipe (21) is sandwiched between the pair of thermoelectric elements (22). A fin group (25) is provided on the surface of each thermoelectric element (22) opposite to the refrigerant pipe (21) side. With this configuration, since the refrigerant pipe (21) is sandwiched between the pair of thermoelectric elements (22), the refrigerant pipe (21) and the thermoelectric element (22) The contact area increases. Therefore, the heat radiation action and the heat absorption action of the refrigerant pipe (21) with respect to the refrigerant are increased. On the other hand, since the fin group (25) is provided in each thermoelectric element (22), the heat absorption effect and the heat radiation effect on the target fluid are increased.

According to a fourth invention, in the second invention,
The thermoelectric element (22) includes the first to third electrodes (2, 3, 8) and a strip electrode array (9) composed of the first and second conductivity type thermoelectric materials (5, 6). Are provided at intervals in the air flow direction,
Each of the strip electrode rows (9) is supplied with currents having different current values.

In the fourth invention, the thermoelectric element (22) is provided with a plurality of strip electrode rows (9) spaced apart from each other in the air flow direction. This strip electrode array (9) is composed of first to third electrodes (2, 3, 8) and first and second conductivity type thermoelectric materials (5, 6), and each strip electrode array (9) Are supplied with currents having different current values.

With such a configuration, the heat exchange efficiency (COP) in each strip electrode array (9) can be maximized. Specifically, in the thermoelectric element (22), the temperature difference between the air and the refrigerant is larger on the upstream side in the air flow direction than on the downstream side. Therefore, when the current value of the current supplied to the thermoelectric element (22) is constant, the heat exchange efficiency is lowered. Therefore, while increasing the current value supplied to the strip electrode array (9) arranged on the upstream side where the temperature difference is large, the current value supplied to the strip electrode array (9) arranged on the downstream side where the temperature difference is small By reducing the size, the heat exchange efficiency can be maximized in all the strip electrode arrays (9).

According to a fifth invention, in the second invention,
The thermoelectric element (22) includes the first to third electrodes (2, 3, 8) and a strip electrode array (9) composed of the first and second conductivity type thermoelectric materials (5, 6). Are provided at intervals in the air flow direction,
Each of the strip electrode rows (9) is electrically connected in series.

In the fifth invention, the thermoelectric element (22) is provided with a plurality of strip electrode arrays (9) spaced apart from each other in the air flow direction. This strip electrode array (9) is composed of first to third electrodes (2, 3, 8) and first and second conductivity type thermoelectric materials (5, 6). Each strip electrode array (9) , Electrically connected in series. With such a configuration, the strip electrode arrays (9) are electrically connected in series, and the surfaces of the first conductive thermoelectric material (5) and the second conductive thermoelectric material (6) formed into a thin film are formed. Current can flow inward.

A sixth invention is the second invention, wherein:
The thermoelectric element (22) includes the first to third electrodes (2, 3, 8) and a strip electrode array (9) composed of the first and second conductivity type thermoelectric materials (5, 6). Are provided at intervals in the air flow direction,
Each of the strip electrode rows (9) is electrically connected in parallel.

In the sixth invention, the thermoelectric element (22) is provided with a plurality of strip electrode rows (9) spaced apart from each other in the air flow direction. This strip electrode array (9) is composed of first to third electrodes (2, 3, 8) and first and second conductivity type thermoelectric materials (5, 6). Each strip electrode array (9) Electrically connected in parallel. With such a configuration, the strip electrode arrays (9) are electrically connected in parallel, and the surfaces of the first conductive thermoelectric material (5) and the second conductive thermoelectric material (6) formed into a thin film are formed. Current can flow inward.

In a seventh aspect based on any one of the fourth to sixth aspects,
Each strip electrode array (9) is characterized in that the widths of the first and second conductivity type thermoelectric materials (5, 6) are different between the upstream side and the downstream side in the air flow direction. .

In the seventh invention, the widths of the first and second conductivity type thermoelectric materials (5, 6) of each strip electrode array (9) are different between the upstream side and the downstream side in the air flow direction. With such a configuration, the heat exchange efficiency (COP) in each strip electrode array (9) can be maximized.

Specifically, in the thermoelectric element (22), the temperature difference between the air and the refrigerant is larger on the upstream side in the air flow direction than on the downstream side. Therefore, when the current value of the current supplied to the thermoelectric element (22) is constant, the heat exchange efficiency is lowered. Here, the first and second conductivity type thermoelectric materials (5, 6) are characterized in that the current that maximizes the heat exchange efficiency increases as the width decreases. Therefore, by utilizing this, the width of the first and second conductivity type thermoelectric materials (5, 6) of the strip electrode array (9) arranged on the upstream side where the temperature difference is large is widened while the temperature difference is small. Narrowing the width of the first and second conductivity type thermoelectric materials (5, 6) of the strip electrode array (9) arranged on the downstream side maximizes the heat exchange efficiency in all strip electrode arrays (9) can do.

According to an eighth invention, in any one of the fourth to sixth inventions,
Each of the strip electrode arrays (9) is characterized in that the thicknesses of the first and second conductivity type thermoelectric materials (5, 6) are different between the upstream side and the downstream side in the air flow direction. .

In the eighth invention, the thicknesses of the first and second conductivity type thermoelectric materials (5, 6) of each strip electrode array (9) are different between the upstream side and the downstream side in the air flow direction. With such a configuration, the heat exchange efficiency (COP) in each strip electrode array (9) can be maximized. Specifically, the first and second conductivity type thermoelectric materials (5, 6) are characterized by the fact that the current that maximizes the heat exchange efficiency increases as the thickness increases. The first and second conductivity type thermoelectric materials (5, 6) of the arranged strip electrode array (9) are made thin, while the first of the strip electrode array (9) arranged on the downstream side with a small temperature difference. Further, by increasing the thickness of the second conductivity type thermoelectric material (5, 6), the heat exchange efficiency can be maximized in all the strip electrode arrays (9).

According to a ninth invention, in any one of the fourth to sixth inventions,
Each of the strip electrode arrays (9) is characterized in that the number of the first and second conductivity type thermoelectric materials (5, 6) is different between the upstream side and the downstream side in the air flow direction. .

In the ninth invention, the number of the first and second conductivity type thermoelectric materials (5, 6) in each strip electrode array (9) is different between the upstream side and the downstream side in the air flow direction. With such a configuration, the heat exchange efficiency (COP) in each strip electrode array (9) can be maximized. Specifically, as the quantity of the first and second conductivity type thermoelectric materials (5, 6) is increased, the voltage at which the heat exchange efficiency is maximized increases. Therefore, the strip electrode array arranged on the upstream side having a large temperature difference. While reducing the quantity of the first and second conductivity type thermoelectric materials (5, 6) of (9), the first and second conductivity type thermoelectrics of the strip electrode array (9) arranged on the downstream side with a small temperature difference By increasing the quantity of the materials (5, 6), the heat exchange efficiency can be maximized in all the strip electrode arrays (9).

According to the present invention, a heat exchanger using a thermoelectric element (22) of a type that radiates heat from one surface of the first insulating substrate (A) and absorbs heat from one surface of the second insulating substrate (B). Is realized. That is, in the first insulating substrate (A) and the second insulating substrate (B), heat absorption and heat dissipation occur on the substrate surface side excluding the opposing surfaces.

Thus, in order to form the first conductive thermoelectric material (5) and the second conductive thermoelectric material (6) in a thin film only between the first insulating substrate (A) and the second insulating substrate (B). Even if the size of the thermoelectric element (22) is increased, an increase in thermal stress acting on the first conductivity type thermoelectric material (5) and the second conductivity type thermoelectric material (6) is suppressed. Moreover, since a current is caused to flow in the in-plane direction of the first conductive type thermoelectric material (5) and the second conductive type thermoelectric material (6) formed into a thin film to cause a temperature difference, the distance from the low temperature side to the high temperature side is The temperature difference increases. In addition, since the first conductive thermoelectric material (5) and the second conductive thermoelectric material (6) are provided between the first insulating substrate (A) and the second insulating substrate (B), Compared with the case where the first conductive thermoelectric material (5) and the second conductive thermoelectric material (6) are provided on the surface, the first conductive thermoelectric material (5) and the second conductive thermoelectric material even when bending force is applied. The tensile stress or compressive stress acting on (6) is reduced, making it difficult to break.

The first to third electrodes (2, 3, 8) and the strip electrode array (9) composed of the first and second conductivity type thermoelectric materials (5, 6) are spaced apart from each other in the air flow direction. And change the current value of the current supplied to each strip electrode row (9), the width and thickness of the first and second conductivity type thermoelectric materials (5, 6) of each strip electrode row (9), By changing the quantity and the like, the heat exchange efficiency (COP) in each strip electrode array (9) can be maximized.

FIG. 1 is a front view schematically showing a configuration of a heat exchanger according to Embodiment 1 of the present invention. 2A is a longitudinal sectional view of the heat exchanger, and FIG. 2B is a sectional view taken along line XX of FIG. 2A. FIG. 3 is a YY cross-sectional view of FIG. FIG. 4 is a cross-sectional view between the insulating substrates of the thermoelectric element. FIG. 5 is a plan view showing the configuration of the thermoelectric element. FIG. 6 is a longitudinal sectional view showing the configuration of the thermoelectric element. FIG. 7A is a graph showing the change in the maximum COP with respect to the current value and the temperature difference, and FIG. 7B is a plan view showing the configuration of the thermoelectric element according to the second embodiment. FIG. 8A is a graph showing a change in the maximum COP with respect to the shape of the thermoelectric material, and FIG. 8B is a diagram corresponding to FIG. 7B of the thermoelectric element according to the third embodiment. FIG. 9A is a graph showing the change in the maximum COP with respect to the number of thermoelectric materials, and FIG. 9B is a diagram corresponding to FIG. 7B of the thermoelectric element according to the fourth embodiment. FIG. 10 is a longitudinal sectional view showing a configuration of a conventional thermoelectric element.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The following embodiments are essentially preferable examples, and are not intended to limit the scope of the present invention, its application, or its use.

Embodiment 1
1 is a front view schematically showing the configuration of a heat exchanger according to Embodiment 1 of the present invention, FIG. 2 is a sectional view showing the configuration of a heat exchanger, and FIG. 3 is a YY sectional view of FIG. is there. As shown in FIGS. 1 to 3, the heat exchanger (10) is a gas cooler that cools air as a target fluid (hereinafter referred to as target air), and includes a plurality of heat exchange modules (20), an inlet, A side header (35) and an outlet side header (36) are provided.

The heat exchange module (20) includes a microchannel (21) as a refrigerant tube through which a refrigerant flows, a pair of thermoelectric elements (22) disposed so as to sandwich the microchannel (21), and a pair of fin groups (25 ). The microchannel (21) constitutes the first fluid flow path member according to the present invention. The fin group (25) constitutes a second fluid flow path member according to the present invention.

The microchannel (21) is composed of a porous flat tube having a plurality of microchannels (21a) inside. The microchannel (21) is formed in a rectangular body that is flat in the flow direction of the target air. The microchannel (21) is formed so that the microchannels (21a) are arranged in a line in the flow direction of the target air.

The thermoelectric element (22) is formed in a strip shape extending in the longitudinal direction of the microchannel (21) (that is, the vertical direction in FIG. 1 and FIG. 2 (a)). Each thermoelectric element (22) is arranged so as to sandwich the microchannel (21) from the flat surface side. The detailed configuration of the thermoelectric element (22) will be described later.

The thermoelectric elements (22) are shorter in length than the microchannel (21) and overlap at other than both ends of the microchannel (21). That is, the thermoelectric element (22) does not overlap at both ends of the microchannel (21). Furthermore, the width of each thermoelectric element (22) is substantially equal to the width of the microchannel (21) (the width of the microchannel (21) is slightly longer).

The fin group (25) is provided on a flat surface opposite to the microchannel (21) side of each thermoelectric element (22). Each fin group (25) includes a base plate (24) in contact with the thermoelectric element (22) and a plurality of heat dissipating fins (27) that exchange heat between the air provided in the base plate (24) and flowing therethrough. It is comprised by what is called a corrugated fin formed by. Note that corrugated fins generally have a small fin thickness, a low fin height, and a narrow fin pitch.

The fin group (25) has a surface opposite to the heat dissipating fin (27) side of the base plate (24) bonded to the flat surface of the thermoelectric element (22). The length of the base plate (24), that is, the length of the fin group (25) is shorter than the length of the microchannel (21) and slightly longer than the length of the thermoelectric element (22). The width of the base plate (24), that is, the width of the fin group (25) is longer than the width of the thermoelectric element (22).

The end plate in the air flow direction and the end plate in the longitudinal direction of the base plate (24) of the fin group (25) are respectively filled with the sealing material (26), and the microchannel (21) and the base plate The gap with (24) is blocked.

In the heat exchange module (20), the microchannel (21) and the thermoelectric element (22) are joined by an adhesive. Further, the thermoelectric element (22) and the base plate (24) of the fin group (25) are joined together by an adhesive. Here, a heat conductive type adhesive is used. Accordingly, the microchannel (21), the thermoelectric element (22), and the fin group (25) are integrally formed to constitute the heat exchange module (20). A plurality of heat exchange modules (20) are juxtaposed in a direction orthogonal to the flow direction of the target air.

The inlet-side header (35) and the outlet-side header (36) are both constituted by circular tubes extending in a direction orthogonal to the flow direction of the target air. The inlet side header (35) is connected to one end side (the upper side of FIG. 2A) which is the inlet end of the microchannel (21) of each heat exchange module (20). The outlet side header (36) is connected to the other end side (the lower side of FIG. 2A) which is the outlet end of the microchannel (21) of each heat exchange module (20). The inlet end and the outlet end of the microchannel (21) protrude and open into the inlet header (35) and the outlet header (36). That is, each heat exchange module (20) is connected in parallel to the inlet side header (35) and the outlet side header (36).

Although not shown, the inlet header (35) is provided with a refrigerant inlet through which refrigerant flows from the outside, and the outlet header (36) is provided with a refrigerant outlet through which refrigerant flows out.

The inlet-side header (35) is configured so that the refrigerant flowing from the outside is distributed and flows into the micro flow path (21a) of the micro channel (21) of each heat exchange module (20). The outlet header (36) is configured such that the refrigerant that has flowed out of the microchannels (21a) of the microchannels (21) merges and flows out.

And the lid | cover (35a, 36a) is attached to the both-ends opening of the said inlet side header (35) and the outlet side header (36). Further, the heat exchanger (10) includes a side plate (37) attached to the lids (35a, 36a) of the inlet side header (35) and the outlet side header (36). That is, the side plate (37) constitutes the right side piece and the left side piece of the heat exchanger (10) when viewed from the air flow direction. In the heat exchanger (10), the gap between the fin groups (25) constitutes the air circulation part (16).

The heat exchanger (10) is provided with a header heat insulating material (31), a side plate heat insulating material (32), and a pipe heat insulating material (33). Specifically, a header heat insulating material (31) is wound around the outer peripheral surfaces of the inlet header (35) and the outlet header (36). A side plate heat insulating material (32) is attached to the inner side surface of the side plate (37) (that is, the surface in contact with the air circulation part (16)). Moreover, the heat insulating material for pipes (33) is provided in the front side (lower side in FIG. 3) and the rear side (upper side in FIG. 3) of the thermoelectric element (22) in the distribution direction of the target air. That is, the front surface and the rear surface of the microchannel (21) and the thermoelectric element (22) are covered with the heat insulating material for pipe (33) so as not to touch the target air.

-Thermoelectric element configuration-
4 is a cross-sectional view between the insulating substrates of the thermoelectric element, FIG. 5 is a plan view, and FIG. 6 is a vertical cross-sectional view. As shown in FIGS. 4 to 6, the thermoelectric element (22) is formed by laminating a first insulating substrate (A) and a second insulating substrate (B).

A plurality of heat absorption side electrodes (2), heat radiation side electrodes (3), p-type thermoelectric materials (5) and n-type thermoelectric materials (6) are formed on the upper surface of the first insulative substrate (A) in a strip shape. Is formed. These are the heat dissipation side electrode (3), n-type thermoelectric material (6), heat absorption side electrode (2), p type thermoelectric material (5), heat dissipation side electrode (3), ..., p type thermoelectric material (5) The heat radiation side electrodes (3) are arranged in this order to form a strip electrode array (9). Electric wires (17, 18) are connected to the heat radiation side electrodes (3) at both ends of the strip electrode array (9). Each of the p-type thermoelectric material (5) and the n-type thermoelectric material (6) is formed into a thin film by a method such as vapor deposition so as to be in contact with the adjacent electrodes (2, 3).

Thus, the p-type thermoelectric material (5) and the n-type thermoelectric material (6) are provided between the first insulating substrate (A) and the second insulating substrate (B) (that is, the p-type thermoelectric material ( 5) and the n-type thermoelectric material (6) are sandwiched between the first insulating substrate (A) and the second insulating substrate (B)), so even if the size of the thermoelectric element (22) is increased, An increase in thermal stress acting on the p-type thermoelectric material (5) and the n-type thermoelectric material (6) is suppressed. Further, even when a bending force is applied, the tensile stress or compressive stress acting on the p-type thermoelectric material (5) and the n-type thermoelectric material (6) is reduced. Therefore, the p-type thermoelectric material (5) and the n-type thermoelectric material (6) can be prevented from being damaged, and a highly reliable thermoelectric element (22) can be provided.

A plurality of strip-shaped heat radiation side electrodes (3) are formed on both surfaces of the first insulating substrate (A) (see FIG. 5). Each of the heat dissipating side electrodes (3) formed on the upper surface of the first insulating substrate (A) is connected to the corresponding heat dissipating side electrode (3) on the lower surface of the first insulating substrate (A) by a through hole (7). It is connected to the. The through hole (7) is formed, for example, by filling a hole formed in the substrate (A) with a paste.

In addition, the said heat absorption side electrode (2) comprises the 1st electrode which concerns on this invention. The heat radiation side electrode (3) constitutes the second electrode according to the present invention. The p-type thermoelectric material (5) and the n-type thermoelectric material (6) constitute the first conductivity type thermoelectric material and the second conductivity type thermoelectric material according to the present invention, respectively.

On the other hand, a plurality of strip-like heat absorption side electrodes (8) are formed on both surfaces of the second insulating substrate (B) (see FIGS. 4 and 5). Each of the heat absorption side electrodes (8) formed on the upper surface of the second insulating substrate (B) is provided with a corresponding heat absorption side electrode (8) on the lower surface of the second insulating substrate (B) by a through hole (7). It is connected to the.

The heat absorption side electrode (8) formed on the lower surface of the second insulating substrate (B) is bonded to the heat absorption side electrode (2) formed on the upper surface of the first insulating substrate (A). Connected through. The bonding layer (12) needs to have heat conductivity, and may be a heat conductive adhesive or the like having no conductivity in addition to a conductive material such as solder. When a non-conductive material is used, no current flows through each heat absorption side electrode (8) and through hole (7) of the substrate (B), and only heat flows. In addition, the heat absorption side electrode (8) comprises the 3rd electrode which concerns on this invention.

The first insulating substrate (A) and the second insulating substrate (B) are preferably insulative and highly heat-insulating. This is to prevent heat leakage from the heat dissipation side (high temperature side) to the heat absorption side (low temperature side). For example, it is conceivable to use glass, resin, foamed resin, or the like.

The electrodes (2, 3, 8) are preferably formed of a material having low electrical resistance and high thermal conductivity (for example, copper, aluminum, etc.). Also, in order to improve the bonding with the p-type thermoelectric material (5) and n-type thermoelectric material (6) and to increase the durability, the electrodes (2, 3, 8) are plated with nickel or gold. It is desirable to apply.

Further, as shown in FIG. 6, the first insulating substrate (A) is provided with a heat radiation side heat transfer plate (13) through an insulating layer (11). On the other hand, a heat absorption side heat transfer plate (14) is provided on the second insulating substrate (B) via an insulating layer (11). Further, a groove is formed on the lower surface of the second insulating substrate (B) to avoid heat conduction between the p-type thermoelectric material (5), the n-type thermoelectric material (6), and the heat radiation side electrode (3). A shaped space (15) is formed. In order to reduce heat conduction, it is desirable to enclose a vacuum or a gas having low heat conductivity (such as chlorofluorocarbon or xenon) in the space (15).

The thermoelectric element (22) absorbs heat at the interface between each endothermic electrode (2) and each thermoelectric material (5,6) by passing a current through the electric wire (17,18) between the endothermic electrodes (3). Is generated, and heat is generated at the interface between each heat radiation side electrode (3) and each thermoelectric material (5, 6). As a result, a temperature difference corresponding to both ends of each thermoelectric material (5, 6) occurs.

In this way, current flows in the in-plane direction of the thermoelectric material (5, 6) formed into a thin film to generate a temperature difference, so the distance from the low temperature side to the high temperature side can be increased, and the temperature difference is increased. Can be taken. Specifically, the thickness of each thermoelectric material (5, 6) is t, the width is W (see FIG. 4), the length is L (see FIG. 6), and the length of the junction with each electrode (2, 3). As Lc (see FIG. 6), since the current flows in the in-plane direction of the thin film, the temperature difference is also applied in the in-plane direction. be able to. In addition, by making W significantly larger than t (for example, about 1000 times) and L being about 10 times t, for example, the element form factor (L / tW) can be made equivalent to that of a normal Peltier module. Can do. Therefore, characteristics (resistance, heat absorption, efficiency, etc.) similar to those of a normal Peltier module can be obtained. Furthermore, by making t a thin film of about 10 μm, W is extremely larger than t (for example, about 1000 times), and L is about 10 times t, for example, the volume of thermoelectric material (LtW) is reduced to a normal Peltier. The volume of the thermoelectric material used for the module can be reduced to about 1/100. As a result, resource saving and cost reduction and environmental compatibility are greatly improved.

It should be noted that the junction surface between each electrode (2, 3) and each thermoelectric material (5, 6) has a loss by reducing the electrical resistance and thermal resistance of the junction and reducing the current density and thermal density of the periphery. It is desirable to make it large (specifically, Lc> t). However, if it is too large, the material is wasted, so there is an optimum value. For the same reason, it is desirable that the thickness of each electrode (2, 3) is larger than the thickness of each thermoelectric material (5, 6).

In the thermoelectric element (22), the heat radiation side electrodes (3) formed on both surfaces of the first insulating substrate (A) are connected to each other by the through holes (7). And radiate heat from the heat-dissipation side heat transfer plate (13). Further, in the thermoelectric element (22), the heat absorption side electrodes (8) on both surfaces of the second insulating substrate (B) are connected to each other by the through holes (7) and the heat absorption side electrodes on the upper surface of the first insulating substrate (A). Since it is connected to (2) via the bonding layer (12), it absorbs heat from the heat absorption side electrode (8) and the heat absorption side heat transfer plate (14) on the upper surface of the second insulating substrate (B).

In the heat exchanger (10), the microchannel (21) is provided on the heat radiating side heat transfer plate (13) side to become a heating surface, and the fin group (25) is provided on the heat absorption side heat transfer plate (14) side. It is a cooling surface. Thereby, the microchannel (21) becomes the heat dissipation side, and the fin group (25) becomes the heat absorption side.

The refrigerant (liquid) that has flowed into the inlet header (35) flows into the microchannel (21) of each heat exchange module (20). On the other hand, the target air flows into the fin group (25) of each heat exchange module (20). The refrigerant flowing into the microchannel (21) is dissipated from the thermoelectric elements (22) on both sides and evaporates. The target air flowing through the fin group (25) is absorbed by the fins and cooled to a predetermined temperature. The cooled target air is supplied to the user side.

-Effect of Embodiment 1-
As described above, according to the heat exchanger (10) according to Embodiment 1, the p-type thermoelectric material (5) is provided only between the first insulating substrate (A) and the second insulating substrate (B). Since the n-type thermoelectric material (6) is formed into a thin film, the thermal stress acting on the p-type thermoelectric material (5) and the n-type thermoelectric material (6) increases even if the size of the thermoelectric element (22) is increased. It is suppressed. In addition, since a current is caused to flow in the in-plane direction of the thin-film formed p-type thermoelectric material (5) and n-type thermoelectric material (6), the distance from the low temperature side to the high temperature side increases, The difference increases. Further, since the p-type thermoelectric material (5) and the n-type thermoelectric material (6) are provided between the first insulating substrate (A) and the second insulating substrate (B), the p-type thermoelectric material ( Compared with the case where 5) and n-type thermoelectric material (6) are provided on the surface, the tensile stress or compressive stress acting on p-type thermoelectric material (5) and n-type thermoelectric material (6) even when bending force is applied. Smaller and less likely to break.

<< Embodiment 2 >>
FIG. 7A is a graph showing the change in the maximum COP with respect to the current value and the temperature difference, and FIG. 7B is a plan view showing the configuration of the thermoelectric element according to the second embodiment. Since the difference from the first embodiment is that currents having different current values are supplied to the respective strip electrode rows (9), the same parts as those in the first embodiment are denoted by the same reference numerals. Only the differences will be described.

As shown in FIG. 7B, the thermoelectric element (22) according to the second embodiment is provided with three strip electrode arrays (9) at intervals in the air circulation direction. The wires (17, 18) are independently connected to the heat radiation side electrodes (3) at both ends of each strip electrode array (9). As a result, currents having different current values can be supplied to the respective strip electrode rows (9).

Here, in the thermoelectric element (22), the temperature difference between the air and the refrigerant on the upstream side in the air flow direction is large, and the temperature difference is small on the downstream side. Therefore, when the current value of the current supplied to each strip electrode array (9) of the thermoelectric element (22) is constant, the maximum position of the heat exchange efficiency (COP) changes as shown in FIG. Therefore, the heat exchange efficiency cannot be maximized in each strip electrode array (9).

Therefore, in the present invention, the current value supplied to the strip electrode array (9) disposed on the upstream side where the temperature difference between the air and the refrigerant is large is increased, while the strip electrode array disposed on the downstream side where the temperature difference is small. The current value supplied to (9) was made smaller. Thereby, the heat exchange efficiency can be maximized in all the strip electrode arrays (9).

<< Embodiment 3 >>
FIG. 8A is a graph showing a change in the maximum COP with respect to the shape of the thermoelectric material, and FIG. 8B is a diagram corresponding to FIG. 7 of the thermoelectric element according to the third embodiment. The difference from Embodiment 1 is that the width and thickness of the p-type thermoelectric material (5) and the n-type thermoelectric material (6) in each strip electrode array (9) are changed.

As shown in FIG. 8 (b), the thermoelectric element (22) according to the third embodiment is provided with three strip electrode rows (9) spaced in the air flow direction. In FIG. 8 (b), the wire (17) is connected to the left heat dissipation side electrode (3) of the upper band electrode array (9), while the right end heat dissipation side electrode (3) is connected to the center band electrode array. The heat dissipation side electrode (3) at the right end of (9) is connected. In addition, the leftmost heat radiation side electrode (3) of the central beltlike electrode array (9) is connected to the leftmost heat radiation side electrode (3) of the lower beltlike electrode array (9), while the rightmost heat radiation side electrode Wire (18) is connected to (3). Thereby, each strip | belt-shaped electrode row | line | column (9) is electrically connected in series.

Here, as shown in FIG. 8A, it can be seen that the maximum position of the heat exchange efficiency varies depending on the shapes of the p-type thermoelectric material (5) and the n-type thermoelectric material (6). Specifically, as the widths of the p-type thermoelectric material (5) and the n-type thermoelectric material (6) are reduced or the thickness is increased, the current value at which the heat exchange efficiency is maximized is increased.

Therefore, in the present invention, the width of the p-type and n-type thermoelectric materials (5, 6) of the strip electrode array (9) arranged on the upstream side where the temperature difference between the air and the refrigerant is large is wide (or thin). On the other hand, the widths of the p-type and n-type thermoelectric materials (5, 6) of the strip electrode array (9) arranged on the downstream side where the temperature difference is small are made narrow (or thick). Thereby, the heat exchange efficiency can be maximized in all the strip electrode arrays (9).

<< Embodiment 4 >>
FIG. 9A is a graph showing the change in the maximum COP with respect to the number of thermoelectric materials, and FIG. 9B is a diagram corresponding to FIG. 7 of the thermoelectric element according to the fourth embodiment. The difference from Embodiment 1 is that the number of thermoelectric materials is changed between the strip electrode arrays (9).

As shown in FIG. 9B, the thermoelectric element (22) according to the fourth embodiment is provided with three strip electrode arrays (9) at intervals in the air circulation direction. Electric wires (17, 18) are connected to the heat radiation side electrodes (3) at both ends of each strip electrode row (9), and each strip electrode row (9) is electrically connected in parallel.

Here, as shown in FIG. 9A, it can be seen that the maximum position of the heat exchange efficiency changes according to the quantity of the p-type thermoelectric material (5) and the n-type thermoelectric material (6). Specifically, the voltage that maximizes the heat exchange efficiency increases as the number of p-type thermoelectric materials (5) and n-type thermoelectric materials (6) increases.

Therefore, in the present invention, the number of p-type and n-type thermoelectric materials (5, 6) in the strip electrode array (9) arranged on the upstream side where the temperature difference between air and refrigerant is large is reduced, while the temperature difference is reduced. The number of p-type and n-type thermoelectric materials (5, 6) in the strip electrode array (9) arranged on the small downstream side was increased. Thereby, the heat exchange efficiency can be maximized in all the strip electrode arrays (9).

<< Other Embodiments >>
The present invention may be configured as follows with respect to the embodiment.

For example, in the above-described embodiment, the heat exchanger (10) as a gas cooler for cooling the target air has been described, but the present invention can also be applied as a gas heater for heating the target air. In that case, by applying a reverse current to the thermoelectric element (22), the microchannel (21) side becomes the heat absorption side, and the fin group (25) side becomes the heat dissipation side. Thus, the target air is radiated and heated by the fin group (25).

In the embodiment, the gas (air) flowing through the fin group (25) is used. However, a liquid (refrigerant) flowing through the microchannel (21) may be used.

Also, the heat exchanger (10) configured by one heat exchange module (20) may be used by omitting the inlet side header (35) and the outlet side header (36).

In the above embodiment, a fin type other than the corrugated fin may be used for the fin group (25), or a pipe having one flow path instead of the microchannel (21) may be used as the refrigerant pipe.

In the above embodiment, the gas (air) flowing through the fin group (25) is used after being cooled or heated, but is not limited to this form. For example, in the heat exchanger (10) of the present invention, a load is connected in place of the power source of the thermoelectric element (22), and heat is input from the outside to the heat absorption side to dissipate the heat from the heat dissipation side. When the temperature is higher than the temperature on the heat dissipation side, a power generation module using the Seebeck effect can be obtained.

As described above, the present invention provides a highly practical effect that a thermoelectric element having a size necessary for ensuring heat exchange performance can be easily produced. The availability is high.

2 Endothermic electrode (first electrode)
3 Heat dissipation side electrode (second electrode)
5 p-type thermoelectric material (first conductivity type thermoelectric material)
6 n-type thermoelectric material (second conductivity type thermoelectric material)
7 Through hole 8 Heat absorption side electrode (3rd electrode)
10 Heat exchanger 21 Micro channel (first fluid flow path member, refrigerant pipe)
22 Thermoelectric element 25 Fin group (second fluid flow path member)
A 1st insulating substrate B 2nd insulating substrate

Claims

A thermoelectric element (22), a first fluid flow path member (21) and a first fluid channel member (21), which are arranged so as to sandwich the thermoelectric element (22) and perform heat exchange between the thermoelectric element (22) and a target fluid A heat exchanger comprising two fluid flow path members (25),
The thermoelectric element (22)
A first insulating substrate (A) and a second insulating substrate (B) that are stacked on each other and extend in a strip shape along the longitudinal direction of the first fluid channel member (21) and the second fluid channel member (25). )When,
A plurality of first electrodes formed on the surface of the first insulating substrate (A) on the second insulating substrate (B) side and spaced apart from each other in the longitudinal direction of the first insulating substrate (A). (2) and
The first insulating substrate (A) is formed on both surfaces of the first insulating substrate (A) so as to be adjacent to the first electrodes (2) and spaced apart from the first electrode (2). A plurality of second electrodes (3) whose both surfaces are connected by through holes (7) extending in the thickness direction of
Through-holes formed on both surfaces of the second insulating substrate (B) at intervals in the longitudinal direction of the second insulating substrate (B) and extending in the thickness direction of the second insulating substrate (B) A plurality of third electrodes (8) having both surfaces connected by holes (7) and having a surface on the first insulating substrate (A) side connected to the first electrode (2);
On the surface of the first insulating substrate (A) on the second insulating substrate (B) side, the first electrode (2) and the second electrode (3) adjacent to the first electrode (2) A heat exchanger comprising: a first conductivity type thermoelectric material (5) and a second conductivity type thermoelectric material (6) formed in a thin film so as to be in contact with each other.
In claim 1,
One of the first and second fluid flow paths (21, 25) is composed of a refrigerant pipe (21) through which a refrigerant as a target fluid flows, and the other is a group of fins that exchange heat with air as a target fluid ( A heat exchanger characterized by comprising 25).
In claim 2,
The thermoelectric element (22) is provided in a pair so as to sandwich the refrigerant pipe (21),
The heat exchanger, wherein the fin group (25) is provided on a surface of each thermoelectric element (22) opposite to the refrigerant pipe (21) side.
In claim 2,
The thermoelectric element (22) includes the first to third electrodes (2, 3, 8) and a strip electrode array (9) composed of the first and second conductivity type thermoelectric materials (5, 6). Are provided at intervals in the air flow direction,
Each of the strip electrode rows (9) is supplied with currents having different current values.
In claim 2,
The thermoelectric element (22) includes the first to third electrodes (2, 3, 8) and a strip electrode array (9) composed of the first and second conductivity type thermoelectric materials (5, 6). Are provided at intervals in the air flow direction,
Each said strip | belt-shaped electrode row | line | column (9) is electrically connected in series, The heat exchanger characterized by the above-mentioned.
In claim 2,
The thermoelectric element (22) includes the first to third electrodes (2, 3, 8) and a strip electrode array (9) composed of the first and second conductivity type thermoelectric materials (5, 6). Are provided at intervals in the air flow direction,
Each of the strip-shaped electrode arrays (9) is electrically connected in parallel.
In any one of claims 4 to 6,
Each of the strip electrode arrays (9) is characterized in that the widths of the first and second conductivity type thermoelectric materials (5, 6) are different between the upstream side and the downstream side in the air flow direction. .
In any one of claims 4 to 6,
Each of the strip electrode rows (9) is characterized in that the thicknesses of the first and second conductivity type thermoelectric materials (5, 6) are different between the upstream side and the downstream side in the air flow direction. .
In any one of claims 4 to 6,
Each of the strip electrode rows (9) is characterized in that the quantity of the first and second conductivity type thermoelectric materials (5, 6) is different between the upstream side and the downstream side in the air flow direction. .