JP6463203B2 - Electrochemical element, electrochemical module including the same, electrochemical device and energy system - Google Patents

Description

  The present invention relates to an electrochemical device, an electrochemical module including the electrochemical device, an electrochemical device, and an energy system.

  The structure of the conventional electrode-supported solid oxide fuel cell is roughly divided into a flat plate type and a cylindrical type. In the cylindrical type, an electrode is first formed into a cylindrical shape, and an electrolyte and other electrodes are formed around it. Was. And the cylindrical electrode played the role as a support body which supports the structure of a fuel cell.

  Patent Document 1 discloses a fuel cell in which an inner electrode as a support is a three-dimensional network structure, and a solid electrolyte and an outer electrode are sequentially provided on the surface of the inner electrode (FIG. 1). Further, as a prior art of the fuel cell, a fuel cell (FIG. 5) is disclosed in which a solid electrolyte and an outer electrode are provided on the outer peripheral surface of a cylindrical inner electrode. The inner electrode is provided with a gas passage hole through which fuel gas or oxygen-containing gas flows. In addition, a fuel cell (FIG. 6) is disclosed in which a solid electrolyte and an outer electrode are provided on the outer peripheral surface of a flat inner electrode. The inner electrode is provided with a plurality of gas passage holes through which fuel gas or oxygen-containing gas flows.

JP 2003-282071 A

  When the inner electrode is used as a support in a solid oxide fuel cell, the support composed of the inner electrode and the like has gas permeability in order to supply fuel gas or oxygen-containing gas to the solid electrolyte disposed outside. It is necessary to have. At the same time, it is necessary to have sufficient strength as a support.

  For this purpose, in the examples of FIG. 5 and FIG. 6 of Patent Document 1, a porous support having passage holes for fuel gas or oxygen-containing gas composed of an inner electrode or the like is added to a binder, slurry adjustment, extrusion molding, drying, It is necessary to form by a temporary baking process or the like. Then, a solid electrolyte or a raw material of the outer electrode material is formed in a slurry or paste sequentially on a support composed of the inner electrode and the like which are pre-fired, and after passing through a drying and pre-baking step, etc., the temperature is about 1300 to 1500 ° C. It needs to be fired at a high temperature. The formed product before the high-temperature firing was very brittle and easily deformed and cracked. Further, the strength of the fuel cell obtained by the high-temperature firing was low and the brittle fracture phenomenon occurred. If the thickness of the inner electrode constituting the support is increased, the deformation and cracking of the fuel cell can be suppressed to some extent. However, the increase in the thickness of the inner electrode reduces the amount of gas supplied to the solid electrolyte, and the fuel cell. Cell performance is degraded.

In the example of FIG. 1 of Patent Document 1, the inner electrode is formed as a three-dimensional network structure to increase the strength, suppress deformation and cracks in the manufacturing process, and reduce the amount of gas supplied to the surface of the solid electrolyte. It can be increased. However, even in this configuration, the manufacturing process is complicated, the resulting fuel cell undergoes a brittle fracture phenomenon when stress is applied, and the thermal conductivity of the constituent material is about 1.5 to 3 Wm ⁻¹ K ^−1. Therefore, there is a problem in that the temperature distribution inside the cell becomes large and stress distribution occurs, leading to destruction, and further improvement in strength, durability and performance as a fuel cell (electrochemical element) has been demanded.

  This invention is made | formed in view of the above-mentioned subject, The objective is to implement | achieve the electrochemical element, electrochemical module, electrochemical apparatus, and energy system which were excellent in intensity | strength, durability, and performance.

  The characteristic configuration of the electrochemical device according to the present invention for achieving the above object is an electrochemical device having a cylindrical support having conductivity and an electrochemical reaction portion, and the electrochemical reaction portion includes: A membrane-like electrolyte layer; a membrane-like fuel electrode; and a membrane-like air electrode, wherein the electrolyte layer is disposed between the fuel electrode and the air electrode, and the cylindrical support is A gas flow allowing portion that allows gas flow between the inside and outside of the cylindrical support, and a gas flow prohibition that prohibits gas flow between the inside and outside of the cylindrical support. And the electrochemical reaction part is disposed outside or inside the cylindrical support so as to cover a part or all of the gas flow allowing part.

  According to the above-described characteristic configuration, the electrochemical reaction portion is arranged outside or inside the cylindrical support. Therefore, the cylindrical support bears the mechanical strength of the entire electrochemical element, so that the electrochemical reaction is performed. The element can be made robust and high in strength. The cylindrical support has a gas flow allowing portion and a gas flow prohibiting portion, and the electrochemical reaction portion is disposed so as to cover a part or all of the gas flow allowing portion. With this structure of the electrochemical element, it is possible to effectively suppress the flow of gas between the inside and the outside of the cylindrical support while allowing the gas to contact the electrochemical reaction part.

  In addition, when the electrochemical device is manufactured, an electrochemical reaction part having a membrane-like electrolyte layer, a membrane-like fuel electrode, and a membrane-like air electrode is formed on the cylindrical support. Moreover, the defect rate at the time of formation of an electrochemical reaction part can be reduced. Furthermore, since the function as an electrochemical element is realized by an electrochemical reaction part having a membrane-like electrolyte layer, fuel electrode, and air electrode, the necessity of using an expensive material for the support as in the conventional case is reduced. In addition, the cost of the electrochemical device can be reduced. That is, the above-described characteristic configuration can increase the strength, durability, performance, and manufacturability of the electrochemical element, and can reduce the manufacturing cost.

  Another characteristic configuration of the electrochemical device according to the present invention is that the cylindrical support is a metal or a metal oxide.

According to the above characteristic configuration, since the cylindrical support is a metal or metal oxide, the strength and conductivity of the cylindrical support are ensured, and the inner side and the outer side of the cylindrical support in the gas flow prohibition portion. It is possible to easily prevent gas flow. In addition, since the conventional support has a low thermal conductivity of about 1.5 to 3 Wm ⁻¹ K ^{−1, the} material inside the cell is transiently moved when subjected to a heat shock or when the electrochemical load fluctuates. The temperature distribution increased and stress distribution was generated, leading to failure. According to the above characteristic configuration, since the cylindrical support is a metal or metal oxide, the thermal conductivity of the cylindrical support can be increased, the temperature distribution inside the cell is reduced, and the stress distribution is generated. Destruction can be avoided. Therefore, an electrochemical element superior in strength, reliability, durability and performance can be realized.

  Another characteristic configuration of the electrochemical device according to the present invention is that the cylindrical support has a plane portion parallel to a central axis of the cylindrical support, and the electrochemical reaction portion is located on the plane portion. It is at the point where it is placed.

  According to the above characteristic configuration, the cylindrical support has a flat portion parallel to the central axis of the cylindrical support, and the electrochemical reaction portion is disposed on the flat portion. It becomes easier and the yield of manufacturing the electrochemical device can be further improved. In addition, the prevention of gas flow between the inside and outside, which is important as an electrochemical element, can be realized more easily and effectively.

  Another characteristic configuration of the electrochemical device according to the present invention is that a membranous intermediate layer is disposed between the air electrode and the electrolyte layer.

  According to the above characteristic configuration, since the membranous intermediate layer is disposed between the air electrode and the electrolyte layer, the reaction between the air electrode constituent material and the electrolyte layer constituent material is effectively suppressed, and the performance It is possible to realize an electrochemical device having excellent long-term stability.

  Another characteristic configuration of the electrochemical device according to the present invention is that a membranous intermediate layer is disposed between the fuel electrode and the electrolyte layer.

  According to said characteristic structure, since a film-like intermediate | middle layer is arrange | positioned between a fuel electrode and an electrolyte layer, the electrochemical element excellent in performance, reliability, and durability can be implement | achieved.

  Another characteristic configuration of the electrochemical device according to the present invention is that the electrolyte layer is disposed so as to cover the gas flow allowing portion.

  According to the above characteristic configuration, since the electrolyte layer is disposed so as to cover the gas flow allowing portion, the inner and outer airtightness of the cylindrical support is realized by installing the electrochemical reaction portion on the cylindrical support. Thus, an electrochemical device having excellent performance can be more easily manufactured.

  Another characteristic configuration of the electrochemical device according to the present invention is that a sealing material for preventing gas flow between the inside and the outside of the cylindrical support is provided at the end of the electrolyte layer.

  According to the above characteristic configuration, since the sealing material for preventing the gas flow between the inside and outside of the cylindrical support is provided at the end of the electrolyte layer, the inner and outer sides of the cylindrical support can be more easily sealed. An electrochemical device that can be realized and has excellent performance can be more easily manufactured.

  Another characteristic configuration of the electrochemical device according to the present invention is that the gas flow allowing portion is a perforated region provided with a plurality of through holes communicating with the inside and the outside of the cylindrical support. is there.

  According to the above characteristic configuration, the gas flow allowing portion is a perforated region in which a plurality of through holes communicating with the inside and the outside of the cylindrical support are provided. In addition to easily and selectively providing the allowance portion, the strength of the cylindrical support can be further increased. Therefore, an electrochemical element that is superior in strength and durability can be realized more easily.

  Another characteristic configuration of the electrochemical device according to the present invention is that the gas flow allowing portion includes an opening provided on a side surface of the cylindrical support with a gas permeable member made of a material having conductivity and gas permeability. It is in the point formed by fixing to.

  According to the above-described characteristic configuration, the gas flow allowing portion is configured such that the gas permeable member made of a material having conductivity and gas permeability is connected to the opening provided on the side surface of the cylindrical support body, such as fitting or welding. Since it is formed fixed by a legal method, the gas flow allowing portion can be formed more easily, and the surface of the gas permeable member can be easily formed flat, thereby forming the electrochemical reaction portion. It is possible to improve the yield. That is, the electrochemical element can be manufactured more easily.

  Another characteristic configuration of the electrochemical element according to the present invention is that when the electrochemical element is attached to another member, one end of the cylindrical support in the axial direction is the other member. It is fixed and the electrochemical element is cantilevered by the other member.

  Electrochemical elements are subject to various fluctuations such as temperature changes and electrochemical load fluctuations during use. For example, when used in a solid oxide fuel cell, the temperature cycle from room temperature to about 800 ° C. is repeatedly received by operation and shutdown. According to said characteristic structure, when an electrochemical element is attached to another member, one edge part is fixed to another member among the axial direction edge parts of a cylindrical support body, and an electrochemical element is other Since it is cantilevered by this member, the generation of stress due to expansion and contraction due to temperature change and vibration due to temperature change in combination with other features of the present invention is dramatically reduced compared to the prior art, and performance is improved. An electrochemical element with better long-term stability can be realized.

  Another characteristic configuration of the electrochemical element according to the present invention is that, of the axial ends of the cylindrical support, the side attached to the other member when the electrochemical element is attached to the other member. The non-arrangement region where the electrochemical reaction portion or the gas flow allowing portion is not provided is provided at the fixed end portion which is the end portion.

  Usually, the electrochemical reaction part is provided in as large an area as possible in order to promote the generation of the electrochemical reaction. According to the above characteristic configuration, among the axial ends of the cylindrical support, when the electrochemical element is attached to another member, the fixed end that is the end attached to the other member, Since the non-arrangement region where the electrochemical reaction part or the gas flow allowing part is not provided is provided, the area contributing to the electrochemical reaction is reduced. However, due to the presence of the non-arrangement region provided at the fixed end, the distance between the junction between the other member and the cylindrical support and the electrochemical reaction portion that becomes high temperature increases. Then, since the thermal influence which a junction part receives from a high temperature electrochemical reaction part becomes small, durability of a junction part improves. In addition, since the bonding portion is at a lower temperature than the electrochemical reaction portion, a bonding member having a relatively low heat-resistant temperature can be used as a bonding member used for bonding the other member and the cylindrical support. The electrochemical element can be easily and inexpensively attached to the battery. Furthermore, since a low-cost material can be used for the cylindrical support, a low-cost electrochemical element can be realized even if a non-arrangement region is provided.

  Another characteristic configuration of the electrochemical element according to the present invention is that, of the axial ends of the cylindrical support, the side attached to the other member when the electrochemical element is attached to the other member. A non-arrangement area where the electrochemical reaction part or the gas flow permissible part is not provided is provided at the fixed end part which is an end part, and the cylindrical support and the part are disposed in any part of the non-arrangement area An insulating member that electrically insulates other members is provided.

  According to said characteristic structure, when an electrochemical element is attached to another member, the insulating member which electrically insulates an electrochemical element and another member is a part of a low temperature area compared with an electrochemical reaction part. Therefore, an insulating member having a relatively low heat resistant temperature and a low cost can be used.

  In order to achieve the above object, the electrochemical module according to the present invention includes a plurality of the above-described electrochemical elements, and one electrochemical element on the side opposite to the cylindrical support in the electrochemical reaction portion. And a plurality of the electric electrodes in a form in which the cylindrical supports of the other electrochemical devices are electrically connected and the axes of the plurality of cylindrical supports are parallel to each other. The chemical element is arranged in parallel.

  According to said characteristic structure, the form on the opposite side to the cylindrical support body in the electrochemical reaction part of one electrochemical element, and the cylindrical support body of another electrochemical element are electrically connected In addition, since the electrochemical module is configured by arranging a plurality of electrochemical elements in parallel in such a manner that the axes of the plurality of cylindrical supports are parallel to each other, electrochemical having excellent strength, durability and performance By using the element, an electrochemical module having excellent durability and performance can be easily realized.

  Another characteristic configuration of the electrochemical module according to the present invention is that the electrochemical element has a gas supply space in which a reaction gas used for a reaction in the electrochemical reaction unit is supplied to a side of the electrochemical reaction unit. A plurality of the electrochemical elements adjacent to each other among the plurality of electrochemical elements arranged in parallel, wherein the electrochemical reaction portion is connected to the other electrochemical element; Regarding the second electrochemical element in which the cylindrical support is connected to the first electrochemical element, the gas supply space of the first electrochemical element and the gas supply space of the second electrochemical element are The second electrochemical element communicates with the side of the cylindrical support.

  When the gas supply space of the electrochemical element is not in communication with each other, a structure for supplying the reaction gas to each of the electrochemical reaction portions of the plurality of electrochemical elements is required, and the structure of the electrochemical module is complicated. become. According to said characteristic structure, an electrochemical element has the gas supply space to which the reaction gas used for the reaction in an electrochemical reaction part is supplied to the side of an electrochemical reaction part, and is arranged in parallel Two electrochemical elements adjacent to each other among the electrochemical elements, the first electrochemical element having the electrochemical reaction portion connected to the other electrochemical element, and the cylindrical support connected to the first electrochemical element. With respect to the second electrochemical element, the gas supply space of the first electrochemical element and the gas supply space of the second electrochemical element communicate with each other through the side of the cylindrical support of the second electrochemical element. Therefore, the supply of the reaction gas to the electrochemical reaction parts of the plurality of electrochemical elements can be realized with a simpler configuration. That is, the reaction gas can be supplied to the electrochemical reaction part through the gas flow allowing part from the inside of the cylindrical support and through the gas supply space communicating with each other from the outside of the cylindrical support. The structure of the electrochemical module can be simplified.

  In order to achieve the above object, the electrochemical device according to the present invention is characterized in that a fuel having the electrochemical module and the reformer described above and supplying a fuel gas containing a reducing component to the electrochemical module. There exists a supply part and the inverter which takes out electric power from the said electrochemical module.

  According to said characteristic structure, the fuel supply part which has an electrochemical module and a reformer, supplies the fuel gas which contains a reducing component with respect to an electrochemical module, and the inverter which takes out electric power from an electrochemical module. Therefore, electric power can be taken out from the electrochemical module excellent in durability and performance, and an electrochemical device excellent in durability and performance can be realized.

  The characteristic configuration of the energy system according to the present invention for achieving the above object is that it has the above-described electrochemical device and an exhaust heat utilization part for reusing heat exhausted from the electrochemical device.

  According to said characteristic structure, since it has the waste heat utilization part which reuses the heat | fever discharged | emitted from the electrochemical apparatus and the electrochemical apparatus, it is excellent in durability and performance, and also the energy system excellent in energy efficiency Can be realized.

  Another characteristic configuration of the electrochemical device according to the present invention is a first configuration in which the fuel electrode is disposed between the electrolyte layer and the cylindrical support, and a reducing component is contained inside the cylindrical support. The point is that gas is supplied.

  According to the above characteristic configuration, the fuel electrode is disposed between the electrolyte layer and the cylindrical support, and the first gas containing the reducing component is supplied into the cylindrical support, so that the cylindrical support is provided. The first gas containing the reducing component can be supplied to the fuel electrode through the gas flow allowing portion of the body, and a highly reliable electrochemical device can be realized with a simpler configuration.

  Another characteristic configuration of the electrochemical module according to the present invention includes a first gas supply unit that supplies the first gas containing a reducing component to the inside of a cylindrical support of a plurality of the electrochemical elements, One of the ends of the electrochemical element is that one end in the axial direction of the cylindrical support is connected to the first gas supply unit.

  According to said characteristic structure, it has the 1st gas supply part which supplies the 1st gas containing a reducing component in the inside of the cylindrical support body of a several electrochemical element, Out of the edge part of an electrochemical element Since one end of the cylindrical support in the axial direction is connected to the first gas supply unit, the first gas is supplied to the plurality of electrochemical elements while improving the reliability by simply configuring the electrochemical module. An electrochemical module that can be supplied and has high output and high reliability can be realized.

  Another characteristic configuration of the electrochemical module according to the present invention includes a second gas supply unit that supplies a second gas containing an oxidizing component to the electrochemical reaction unit from the outside of the cylindrical support. It is in.

  According to said characteristic structure, since it has a 2nd gas supply part which supplies the 2nd gas containing an oxidizing component with respect to an electrochemical reaction part from the exterior of a cylindrical support body, with respect to an electrochemical reaction part The second gas containing an oxidizing component can be supplied with a simple configuration, and a more simple and highly reliable electrochemical module can be realized.

  Another characteristic configuration of the electrochemical device according to the present invention is a third feature in which the air electrode is disposed between the electrolyte layer and the cylindrical support, and an oxidizing component is contained inside the cylindrical support. The point is that gas is supplied.

  According to said characteristic structure, since an air electrode is arrange | positioned between an electrolyte layer and a cylindrical support body, and the 3rd gas containing an oxidizing component is supplied inside a cylindrical support body, a cylindrical support The third gas containing an oxidizable component can be supplied to the air electrode through the gas flow allowing portion of the body, and a simpler and more reliable electrochemical device can be realized.

  Another characteristic configuration of the electrochemical device according to the present invention includes a third gas supply unit that supplies the third gas containing an oxidizing component to the inside of a cylindrical support of the plurality of electrochemical devices, One of the ends of the electrochemical element is that one end in the axial direction of the cylindrical support is connected to the third gas supply unit.

  According to said characteristic structure, it has the 3rd gas supply part which supplies the 3rd gas containing an oxidizing component in the inside of the cylindrical support body of a several electrochemical element, Out of the edge part of an electrochemical element Since one end of the cylindrical support in the axial direction is connected to the third gas supply unit, the second gas is supplied to the plurality of electrochemical elements while simply configuring the electrochemical module to improve reliability. An electrochemical module that can be supplied and has high output and high reliability can be realized.

  Another characteristic configuration of the electrochemical element according to the present invention includes a fourth gas supply unit that supplies the fourth gas containing the reducing component to the electrochemical reaction unit from the outside of the cylindrical support. In the point.

  According to said characteristic structure, since it has the 4th gas supply part which supplies 4th gas containing a reducing component with respect to an electrochemical reaction part from the exterior of a cylindrical support body, with respect to an electrochemical reaction part A fourth gas containing a reducing component can be supplied with a simple configuration, and an electrochemical module that performs an electrochemical reaction more efficiently can be realized.

Schematic which shows the whole structure of the energy system which concerns on 1st Embodiment. Explanatory drawing of the electrochemical module which concerns on 1st Embodiment Explanatory drawing of the electrochemical element which concerns on 1st Embodiment Sectional view in the direction of IV-IV in FIG. Sectional view in the VV direction of FIG. Sectional view of VI-VI direction of Fig.2 (a) Explanatory drawing of the manufacturing process of the electrochemical element which concerns on 1st Embodiment. Explanatory drawing of the electrochemical element which concerns on 2nd Embodiment Explanatory drawing of the electrochemical element which concerns on 3rd Embodiment Explanatory drawing of the electrochemical element which concerns on 4th Embodiment Explanatory drawing of the electrochemical element which concerns on 4th Embodiment Explanatory drawing of the electrochemical element which concerns on 5th Embodiment

<First Embodiment>
Hereinafter, an energy system, an electrochemical device, an electrochemical module, and an electrochemical element according to a first embodiment will be described with reference to the drawings.

<Energy system, electrochemical device>
FIG. 1 shows an overview of an energy system and an electrochemical device.
The energy system includes an electrochemical device and a heat exchanger 23 as a waste heat utilization unit that reuses heat discharged from the electrochemical device.
The electrochemical device has an electrochemical module M, a desulfurizer 1 and a reformer 4, a fuel supply unit that supplies a fuel gas containing a reducing component to the electrochemical module M, and an electrochemical module M And an inverter 8 for extracting power from the inverter 8.

  Specifically, the electrochemical device includes a desulfurizer 1, a reforming water tank 2, a vaporizer 3, a reformer 4, a blower 5, a combustion unit 6, an inverter 8, a control unit 9, a storage container 10, and an electrochemical module M. .

  The desulfurizer 1 removes (desulfurizes) sulfur compound components contained in hydrocarbon-based raw fuel such as city gas. In the case where a sulfur compound is contained in the raw fuel, by providing the desulfurizer 1, the influence of the sulfur compound on the reformer 4 or the electrochemical element E can be suppressed. The vaporizer 3 generates steam from the reformed water supplied from the reformed water tank 2. The reformer 4 steam-reforms the raw fuel desulfurized in the desulfurizer 1 using the steam generated in the vaporizer 3 to generate a reformed gas containing hydrogen.

  The electrochemical module M uses the reformed gas supplied from the reformer 4 and the air supplied from the blower 5 to cause an electrochemical reaction to generate power. The combustion unit 6 mixes the reaction exhaust gas discharged from the electrochemical module M and air, and combusts the combustible component in the reaction exhaust gas.

  The electrochemical module M includes a plurality of electrochemical elements E and a gas manifold 17. The plurality of electrochemical elements E are arranged in parallel while being electrically connected to each other, and one end (lower end) of the electrochemical element E is fixed to the gas manifold 17. The electrochemical element E generates electricity by causing an electrochemical reaction between the reformed gas supplied through the gas manifold 17 and the air supplied from the blower 5.

  The inverter 8 adjusts the output power of the electrochemical module M to the same voltage and the same frequency as the power received from the commercial system (not shown). The control unit 9 controls the operation of the electrochemical device and the energy system.

  The vaporizer 3, the reformer 4, the electrochemical module M, and the combustion unit 6 are stored in a storage container 10. The reformer 4 performs the raw fuel reforming process using the combustion heat generated by the combustion of the reaction exhaust gas in the combustion unit 6.

  The raw fuel is supplied to the desulfurizer 1 through the raw fuel supply path 12 by the operation of the booster pump 11. The reforming water in the reforming water tank 2 is supplied to the vaporizer 3 through the reforming water supply path 14 by the operation of the reforming water pump 13. The raw fuel supply path 12 is downstream of the desulfurizer 1 and is joined to the reformed water supply path 14, and the reformed water and raw fuel merged outside the storage container 10 are stored in the storage container. 10 is supplied to the vaporizer 3 provided in the inside.

  The reformed water is vaporized by the vaporizer 3 to become water vapor. The raw fuel containing steam generated by the vaporizer 3 is supplied to the reformer 4 through the steam-containing raw fuel supply path 15. The raw fuel is steam reformed in the reformer 4 to generate a reformed gas (first gas having a reducing component) containing hydrogen gas as a main component. The reformed gas generated in the reformer 4 is supplied to the gas manifold 17 of the electrochemical module M through the reformed gas supply path 16.

  The reformed gas supplied to the gas manifold 17 is distributed to the plurality of electrochemical elements E, and is supplied to the electrochemical elements E from the lower end, which is a connection portion between the electrochemical elements E and the gas manifold 17. Hydrogen (reducing component) in the reformed gas is mainly used for electrochemical reaction in the electrochemical element E. The reaction exhaust gas containing the remaining hydrogen gas that has not been used for the reaction is discharged from the upper end of the electrochemical element E to the combustion unit 6.

  The reaction exhaust gas is combusted in the combustion unit 6 and becomes combustion exhaust gas, and is discharged from the combustion exhaust gas outlet 20 to the outside of the storage container 10. A combustion catalyst section 21 (for example, a platinum-based catalyst) is disposed at the combustion exhaust gas outlet 20 to burn and remove reducing components such as carbon monoxide and hydrogen contained in the combustion exhaust gas. The combustion exhaust gas discharged from the combustion exhaust gas outlet 20 is sent to the heat exchanger 23 through the combustion exhaust gas discharge path 22.

  The heat exchanger 23 exchanges heat between the combustion exhaust gas generated by the combustion in the combustion unit 6 and the supplied cold water to generate hot water. That is, the heat exchanger 23 operates as an exhaust heat utilization unit that reuses the heat exhausted from the electrochemical device.

<Electrochemical module M>
Next, the electrochemical module M will be described with reference to FIG. The electrochemical module M has a plurality of electrochemical elements E, the surface of the electrochemical reaction part 43 of one electrochemical element E opposite to the cylindrical support 31, and the cylindrical shape of the other electrochemical elements E A plurality of electrochemical elements E are arranged in parallel so that the support 31 is electrically connected and the axes of the plurality of cylindrical supports 31 are parallel to each other.

  The electrochemical module M has a first gas supply unit (gas manifold 17) for supplying a first gas containing a reducing component into the cylindrical support 31 of the plurality of electrochemical elements E. One end of the cylindrical support 31 in the axial direction among the ends of the element E is connected to the first gas supply unit.

  And the electrochemical module M has the 2nd gas supply part (blower 5) which supplies the 2nd gas (air) containing an oxidizing component with respect to the electrochemical reaction part 43 from the exterior of the cylindrical support body 31. FIG.

  When the electrochemical element E is attached to another member (in this embodiment, the gas manifold 17), one end of the end portions in the axial direction of the cylindrical support 31 is fixed to the other member. Thus, the electrochemical element E is cantilevered by another member.

  Specifically, as shown in FIGS. 2A and 2B, the electrochemical module M includes an electrochemical element E, a gas manifold 17, a current collecting member 26, a termination member 27, and a current drawing portion 28.

  The electrochemical element E includes an electrochemical reaction portion 43 on the surface of a cylindrical support 31 that is a hollow cylinder, and takes the shape of a long flat plate or a flat bar as a whole. One end portion of the electrochemical element E in the longitudinal direction is fixed to the gas manifold 17 by an adhesive member such as a glass sealing material. The cylindrical support 31 and the gas manifold 17 are electrically insulated.

  Further, the connection between the cylindrical support 31 and the gas manifold 17 is such that the reformed gas supplied from the reformer 4 to the gas manifold 17 can be supplied from the gas manifold 17 to the cylindrical support 31. The inside of the cylindrical support 31 (reformed gas flow portion 36 described later) and the internal space (not shown) of the gas manifold 17 are communicated. The connecting portion between the cylindrical support 31 and the gas manifold 17 is kept airtight so that the reformed gas does not leak out and air does not flow into the cylindrical support 31.

  The electrochemical reaction part 43 of the electrochemical element E is configured as a film as a whole. Of the front and back surfaces of the electrochemical reaction unit 43, the current collecting member 26 is bonded to the surface opposite to the cylindrical support 31 with an adhesive 29. A plurality of electrochemical elements E are arranged in parallel in a state where the back surface 39 of another electrochemical element E and the current collecting member 26 are in contact with each other or are joined by welding or the like.

  As the current collecting member 26, a member having conductivity, gas permeability, and elasticity in the direction in which the electrochemical elements E are arranged in parallel is used. For example, the current collecting member 26 is an expanded metal using a metal foil, a metal mesh, or a felt-like member. For the adhesive 29, a material having conductivity and gas permeability is used. For example, a ceramic adhesive is used for the adhesive 29. As a result, the current collecting member 26 and the adhesive material 29 have gas permeability and gas flow properties, and the air supplied from the blower 5 permeates or flows through the current collecting member 26 and the adhesive material 29, and the electrochemical reaction unit 43. To be supplied.

  Further, since the current collecting member 26 has elasticity in the direction of parallel arrangement of the electrochemical elements E, the cylindrical support 31 cantilevered by the gas manifold 17 can be displaced in the direction of parallel arrangement, and vibration or The robustness of the electrochemical module M against disturbances such as temperature changes is enhanced.

  A plurality of electrochemical elements E arranged in parallel are sandwiched between a pair of termination members 27. The end member 27 is a member that is conductive and elastically deformable, and its lower end is fixed to the gas manifold 17. The termination member 27 is connected to a current drawing portion 28 that extends outward along the direction in which the electrochemical elements E are arranged in parallel. The current drawing unit 28 is connected to the inverter 8 and sends a current generated by the power generation of the electrochemical element E to the inverter 8.

  As shown in FIG. 2, the electrochemical elements E arranged in parallel have air (reaction gas, second gas containing an oxidative component) used for the reaction in the electrochemical reaction unit 43 on the side of the electrochemical reaction unit 43. ) Is supplied to the gas supply space S. And the gas supply space S which the some electrochemical element E has is mutually connected by the side of the cylindrical support body 31, and becomes a continuous space. Here, the side of the electrochemical reaction part 43 is a direction orthogonal to both the axial direction of the cylindrical support 31 and the direction of the parallel arrangement of the electrochemical reaction part 43.

  If it demonstrates in detail using FIG. 2, the electrochemical element E1 will have gas supply space S1, the electrochemical element E2 will have gas supply space S2, and the electrochemical element E3 will have gas supply space S3. And gas supply space S1 and gas supply space S2 are connected via the side of the cylindrical support body 31 of the electrochemical element E2. Moreover, gas supply space S2 and gas supply space S3 are connected via the side of the cylindrical support body 31 of the electrochemical element E3. In FIG. 2, the arrow of the gas supply space S indicates the upper side of the electrochemical reaction unit 43 in the drawing, but the gas supply space S also exists on the lower side of the electrochemical reaction unit 43 in the drawing. .

  That is, the first electrochemical in which two adjacent electrochemical elements (E1, E2) among the plurality of electrochemical elements E arranged in parallel are connected to the other electrochemical element E2. Regarding the element E1 and the second electrochemical element E2 in which the cylindrical support 31 is connected to the first electrochemical element E1, the gas supply space S1 of the first electrochemical element E1 and the gas supply space of the second electrochemical element E2 S2 communicates with the side of the cylindrical support 31 of the second electrochemical element E2.

  Since the gas supply spaces S communicate with each other in this way, the air supplied from the blower 5 to the inside of the storage container 10 reaches the gas supply space S and is supplied to the electrochemical reaction unit 43. Further, the reformed gas is supplied from the gas manifold 17 to the inside of the cylindrical support 31 (reformed gas flow part 36), and thus the reformed gas is supplied to the electrochemical reaction part 43. As a result, the reaction proceeds in the electrochemical reaction unit 43.

<Electrochemical element E>
The schematic structure of the electrochemical element E is shown by FIGS. The electrochemical element E includes a cylindrical support 31 having conductivity and an electrochemical reaction part 43. The electrochemical reaction part 43 includes a membrane-like electrolyte layer 46, a membrane-like fuel electrode 44, A membrane-like air electrode 48, the electrolyte layer 46 is disposed between the fuel electrode 44 and the air electrode 48, and the cylindrical support 31 is a gas between the inside and the outside of the cylindrical support 31. A gas flow permissible portion P2 that permits the flow of gas, and a gas flow prohibition portion P1 that prohibits the flow of gas between the inside and the outside of the cylindrical support 31, and the electrochemical reaction portion 43. Is disposed outside the cylindrical support 31 so as to cover part or all of the gas flow allowing portion P2.

<Cylindrical support 31>
The cylindrical support 31 includes a rectangular flat plate member 32, a U-shaped member 33 having a U-shaped cross section orthogonal to the longitudinal direction, and a lid portion 34. The long side of the flat plate member 32 and the long side of the U-shaped member 33 (sides corresponding to the two vertices of the U-shape) are joined, and one end is closed by the lid 34. Thereby, the cylindrical support body 31 which has a space inside and is flat or flat as a whole is configured. The flat plate member 32 is disposed in parallel to the central axis of the cylindrical support 31.

  The space inside the cylindrical support 31 functions as the reformed gas flow part 36. A reaction exhaust gas outlet 37 is formed in the lid 34. The opposite end facing the end where the lid 34 is provided is open and functions as the reformed gas inlet 35.

  As the material of the flat plate member 32, the U-shaped member 33, and the lid portion 34, a material having excellent conductivity, heat resistance, oxidation resistance, and corrosion resistance is used. For example, ferritic stainless steel, austenitic stainless steel, nickel base alloy or the like is used. That is, the cylindrical support 31 is configured to be robust. In particular, ferritic stainless steel is preferably used. In addition, in order to comprise the gas flow prohibition part P1 mentioned later, it is necessary to form the flat plate member 32, the U-shaped member 33, and the cover part 34 with the material which does not permeate | transmit gas.

  When ferritic stainless steel is used as the material of the cylindrical support 31, YSZ (yttrium stabilized zirconia), GDC (also referred to as gadolinium-doped ceria, CGO), etc. used for the material in the electrochemical reaction section 43 The thermal expansion coefficient is close. Therefore, even when the temperature cycle of low temperature and high temperature is repeated, the electrochemical element E is not easily damaged. Therefore, it is preferable because an electrochemical element E having excellent long-term durability can be realized.

Incidentally as the material of the cylindrical support member 31, it is preferable to use a material thermal conductivity greater than 3Wm ^-1 K ^-1, more preferably as long as the material above the 10Wm ^-1 K ^-1. For example, since stainless steel has a thermal conductivity of about 15 to 30 Wm ⁻¹ K ^−1, it is suitable as a material for the cylindrical support 31.

  Further, the material of the cylindrical support 31 is more preferably a high toughness material that does not cause brittle fracture. A metal material has high toughness as compared with a ceramic material or the like, and is suitable as the cylindrical support 31.

  The flat plate member 32 is provided with a plurality of through holes 38 that penetrate the front surface and the back surface of the flat plate member 32. Gas can flow between the inside and the outside of the cylindrical support 31 through the through-hole 38. That is, the region where the plurality of through holes 38 are provided (perforated region P2) functions as the gas flow allowing portion (P2). On the other hand, gas cannot flow between the inner side and the outer side of the cylindrical support 31 in a region where the through hole 38 in the flat plate member 32 and the U-shaped member 33 is not provided. Therefore, this region functions as a gas flow prohibition portion (P2).

<Electrochemical reaction part 43>
As shown in FIGS. 4 and 5, the electrochemical reaction unit 43 includes a fuel electrode 44, an intermediate layer 45, an electrolyte layer 46, an intermediate layer 47, and an air electrode 48. In this embodiment, in this order. And laminated on the flat plate member 32. In addition, in the electrochemical element E, the member which covers all or one part of the side of the electrochemical reaction part 43 is not provided, but the side of the electrochemical reaction part 43 is open | released.

  The fuel electrode 44 is provided in a membrane state in a region larger than the perforated region P2 (the gas flow allowing portion P2) where the through hole 38 of the flat plate member 32 is provided. Examples of the material of the fuel electrode 44 include NiO-cerium oxide (ceria) as a main component, Ni-cerium oxide (ceria) as a main component, NiO-zirconia as a main component, Ni-zirconia. A cermet material such as a material mainly composed of CuO-cerium oxide (ceria) or a material mainly composed of Cu-cerium oxide (ceria) can be used. Note that cerium oxide (ceria), zirconia, or the like or a solid solution doped with a different element is referred to as a cermet aggregate. The fuel electrode 44 is formed to have gas permeability. For example, the fuel electrode 44 is configured to have a plurality of fine pores on the surface and inside thereof.

  The fuel electrode 44 is a low temperature firing method (for example, a wet method using a firing treatment in a low temperature region of about 1100 ° C. or less without performing a firing treatment in a high temperature region such as 1400 ° C.), an aerosol deposition method, a thermal spraying method, It is preferably formed by a sputtering method, a pulse laser deposition method or the like. By these processes that can be used in the low temperature range, a good fuel electrode 44 can be obtained by processing in a low temperature range of about 1100 ° C. or less, for example, without using firing in a high temperature range of 1400 ° C. or the like. Therefore, the elemental interdiffusion between the metal flat plate member 32 and the fuel electrode 44 can be suppressed without damaging the metal flat plate member 32, and the electrochemical element E having excellent durability can be realized. preferable. Furthermore, it is more preferable to use a low-temperature firing method because handling of raw materials becomes easy.

  The intermediate layer 45 is provided in the form of a film between the fuel electrode 44 and the electrolyte layer 46. As a material of the intermediate layer 45, for example, a cerium oxide material, a zirconia material, or the like can be used. By introducing the intermediate layer 45 between the fuel electrode 44 and the electrolyte layer 46, the performance, reliability, and durability of the electrochemical reaction unit 43 can be improved.

  The electrolyte layer 46 is provided in the form of a film between the intermediate layer 45 and the intermediate layer 47. As the material of the electrolyte layer 46, solid electrolyte materials such as various zirconia materials, cerium oxide materials, and various perovskite complex oxides can be used. In particular, zirconia ceramics are preferably used. When the electrolyte layer 46 is made of zirconia-based ceramics, the temperature during operation of the electrochemical element E can be made higher than that of ceria-based ceramics, and an extremely efficient electrochemical device can be configured.

  The electrolyte layer 46 is a low-temperature firing method (for example, a wet method using a firing treatment in a low temperature region of about 1100 ° C. or less without performing a firing treatment in a high temperature region such as 1400 ° C.), an aerosol deposition method, a thermal spraying method, It is preferably formed by a sputtering method, a pulse laser deposition method or the like. By these film forming processes that can be used in a low temperature range, a dense and highly airtight electrolyte layer can be obtained by processing in a low temperature range of about 1100 ° C. or less, for example, without using baking in a high temperature range such as 1400 ° C. 46 is obtained. Therefore, elemental interdiffusion between the metal flat plate member 32 and the fuel electrode 44 can be suppressed, and an electrochemical element E having excellent durability can be realized.

  The electrolyte layer 46 is densely configured to maintain hermeticity. The electrolyte layer 46 preferably includes a layer having a relative density of 90% or more. Further, it is more preferable that a layer having a relative density of 95% or more is included, and it is more preferable that a layer having a relative density of 98% or more is included. Thus, it can be set as a precise | minute electrolyte layer by setting it as an electrolyte layer with a high relative density. Here, the relative density represents the ratio of the density of the electrolyte layer 46 actually formed to the theoretical density of the electrolyte material.

  The intermediate layer 47 is provided as a film between the electrolyte layer 46 and the air electrode 48. As a material of the intermediate layer 47, for example, a cerium oxide material, a zirconia material, or the like is used. By introducing the intermediate layer 47 between the air electrode 48 and the electrolyte layer 46, the reaction between the constituent material of the air electrode 48 and the constituent material of the electrolyte layer 46 is effectively suppressed, and the performance of the electrochemical reaction unit 43. Can improve long-term stability.

  The air electrode 48 is provided as a film on the intermediate layer 47. Examples of the material of the air electrode 48 include composites such as LSCF (La—Sr—Co—Fe oxide), LSC (La—Sr—Co oxide), and LSM (La—Sr—Mn oxide). An oxide can be used. Note that the air electrode 48 is formed by a low temperature baking method (for example, a wet method using a baking process in a low temperature region of about 1100 ° C. or less without performing a baking process in a high temperature region such as 1400 ° C.), an aerosol deposition method, or thermal spraying. Preferably, it is formed by a method, a sputtering method, a pulse laser deposition method or the like. By these processes that can be used in a low temperature range, a favorable air electrode 48 can be obtained by processing in a low temperature range of about 1100 ° C. or less, for example, without using baking in a high temperature range of 1400 ° C., for example. Therefore, it is preferable because the elemental interdiffusion between the flat plate member 32 and the fuel electrode 44 can be suppressed without damaging the metal flat plate member 32 and the electrochemical element E having excellent durability can be realized.

  The electrochemical reaction part 43 is disposed so as to cover a part or all of the perforated region P2 in the flat plate member 32 where the plurality of through holes 38 are provided, that is, the gas flow allowing part P2. In this embodiment, as shown in FIG. 4, the electrochemical reaction part 43 covers the entire perforated region P2. The electrolyte layer 46 of the electrochemical reaction unit 43 covers the entire perforated region P2, covers the entire fuel electrode 44, and covers the entire intermediate layer 45. The electrolyte layer 46 is provided across (crossing) the perforated region P2 (gas flow permitting portion P2) of the flat plate member 32 and the region where the through hole 38 is not provided in the flat plate member 32 (gas flow prohibiting portion P1). It is done. That is, the electrolyte layer 46 is provided in contact with the gas flow allowing portion P <b> 2 of the flat plate member 32. Thereby, the coupling | bonding of the electrochemical reaction part 43 and the cylindrical support body 31 is strengthened.

  The electrochemical device E configured as described above is configured as an electrochemical module M, and operates as follows to generate electric power.

  As shown in FIGS. 2 and 6, the electrochemical element E is arranged in parallel with the gas manifold 17 in a state where the plurality of electrochemical elements E are electrically connected via the current collecting member 26 and the adhesive 29. Is done. The end opposite to the end provided with the lid 34 and the reaction exhaust gas discharge port 37 (the end in the lower part of the drawing in FIG. 5) is fixed to the gas manifold 17. The gas manifold 17 supplies the reformed gas to the reformed gas inlet 35. The electrochemical element E is maintained at an operating temperature of about 700 ° C.

  The reformed gas supplied to the reformed gas inlet 35 flows toward the reaction exhaust gas outlet 37 through the reformed gas flow passage 36. On the way, a part of the reformed gas flows out from the inner side to the outer side of the cylindrical support 31 through the through hole 38 and reaches the fuel electrode 44 of the electrochemical reaction unit 43. On the other hand, the air supplied from the blower 5 to the storage container 10 reaches the gas supply space S of the electrochemical element E. Air from the gas supply space S reaches the air electrode 48 of the electrochemical reaction unit 43 through the current collecting member 26 and the adhesive 29 or directly from the side of the electrochemical reaction unit 43.

As a result, the oxygen O ₂ contained in the air reacts with the electrons e ^{− at} the air electrode 48 to generate oxygen ions O ²⁻ . The oxygen ions O ²⁻ move through the electrolyte layer 46 to the fuel electrode 44. In the fuel electrode 44, hydrogen H ₂ contained in the supplied reformed gas reacts with oxygen ions O ²⁻ to generate water H ₂ O and electrons e ⁻ . Also, carbon monoxide CO contained in the supplied reformed gas reacts with oxygen ions O ²⁻ to generate carbon dioxide CO ₂ and electrons e ⁻ . Due to the above reaction, an electromotive force is generated between the fuel electrode 44 and the air electrode 48.

  The current collecting member 26 is connected to the air electrode 48 of one electrochemical reaction unit 43 via the adhesive 29, and the current collecting member 26 contacts the back surface 39 of the other cylindrical support 31. Since the plurality of electrochemical elements E are connected in series in this way, a voltage obtained by adding the electromotive forces generated in the electrochemical elements E is generated in the current extraction unit 28.

  The reformed gas that has reached the end of the reformed gas flow section 36 is discharged as a reaction exhaust gas from the reaction exhaust gas outlet 37 to the outside of the electrochemical element E together with the remaining hydrogen gas that has not been consumed in the electrochemical reaction section 43. Is done. The reaction exhaust gas discharged from the reaction exhaust gas discharge port 37 is mixed with the air supplied to the storage container 10 from the blower 5 and burned in the combustion section 6 near the reaction exhaust gas discharge port 37 to heat the reformer 4. To do.

Next, with reference to FIG. 7, the manufacturing procedure of the electrochemical element E will be described.
First, a plurality of through holes 38 are formed in the flat plate member 32 (FIG. 7A). The through hole 38 can be formed by, for example, laser processing. As a result, the flat plate member 32 is selectively provided with the gas flow allowing portion P2 (perforated region P2) and the gas flow prohibiting portion P1.

  Next, an electrochemical reaction portion 43 is provided so as to cover the entire perforated region P <b> 2 of the flat plate member 32. The electrochemical reaction unit 43 is provided in the order of the fuel electrode 44, the intermediate layer 45, the electrolyte layer 46, the intermediate layer 47, and the air electrode 48. These are all formed on the flat plate member 32 in a film state. Formation of the electrochemical reaction part 43 can be appropriately performed using a wet method such as printing or spraying, an aerosol deposition method, a thermal spraying method, a sputtering method, a pulse laser deposition method, or the like.

  Finally, the U-shaped member 33 and the lid portion 34 in which the reaction exhaust gas discharge port 37 is previously formed are joined to the flat plate member 32. For joining each member, an appropriate method such as welding can be used.

Second Embodiment
In the first embodiment described above, the electrochemical reaction unit 43 is provided on the flat plate member 32 in the order of the fuel electrode 44, the intermediate layer 45, the electrolyte layer 46, the intermediate layer 47, and the air electrode 48. A reformed gas containing hydrogen gas is supplied from the gas manifold 17 to the inside of the cylindrical support 31, and air is supplied from the blower 5 to the outside of the cylindrical support 31, so that an electrochemical reaction proceeds.

  In the second embodiment, in the electrochemical reaction part 43 of the electrochemical element E, the air electrode 48 is disposed between the electrolyte layer 46 and the cylindrical support 31, and an oxidizing component is introduced into the cylindrical support 31. The contained third gas (air) is supplied. And the electrochemical module M has the 3rd gas supply part (gas manifold 17) which supplies the 3rd gas (air) containing an oxidizing component inside the cylindrical support body 31 of the several electrochemical element E. As shown in FIG. One end portion in the axial direction of the cylindrical support 31 among the end portions of the electrochemical element E is connected to the third gas supply portion. The electrochemical module M further includes a fourth gas supply unit (reformer 4) for supplying a fourth gas (reformed gas) containing a reducing component to the electrochemical reaction unit 43 from the outside of the cylindrical support 31. ).

  FIG. 8 shows a cross section of an electrochemical element E according to the second embodiment. The electrochemical reaction unit 43 is provided on the flat plate member 32 in the order of the air electrode 48, the intermediate layer 47, the electrolyte layer 46, the intermediate layer 45, and the fuel electrode 44. That is, they are provided in the reverse order to the first embodiment.

  Although not shown for the electrochemical module M according to the second embodiment, the current collecting member 26 is bonded to the fuel electrode 44 of the electrochemical reaction unit 43 by the adhesive 29. And the several electrochemical element E is arrange | positioned in parallel in the state which the back surface 39 of another electrochemical element E and the current collection member 26 are made to contact.

  Air is supplied from the gas manifold 17 to the inside of the cylindrical support 31 of the electrochemical element E. The air supplied from the gas manifold 17 is supplied to the air electrode 48 of the electrochemical reaction part 43 through the gas flow allowing part P2 (perforated region P2) of the cylindrical support 31.

  The reformed gas is supplied from the reformer 4 into the storage container 10 and reaches the gas supply space S of the electrochemical element E. Then, the reformed gas is supplied from the gas supply space S to the fuel electrode 44 of the electrochemical reaction section 43 through the current collecting member 26 and the adhesive 29 or directly from the side of the electrochemical reaction section 43. The Then, a power generation reaction (electrochemical reaction) proceeds in the electrochemical reaction unit 43 as in the first embodiment described above.

<Third Embodiment>
In the first embodiment described above, the reformed gas that has flowed from the reformed gas inlet 35 of the cylindrical support 31 flows through the reformed gas flow section 36, passes through the reaction exhaust gas discharge port 37, and the electrochemical element E. Was discharged outside. In the third embodiment, the reaction exhaust gas is guided to the gas manifold 17 and reused as fuel.

  FIG. 9 shows an electrochemical element E according to the third embodiment. A partition plate 51 is disposed in the reformed gas flow portion 36 of the cylindrical support 31. The reaction exhaust gas outlet 37 is not provided in the lid portion 34 but is provided at an end portion where the reformed gas inlet 35 is provided. The reformed gas supplied from the gas manifold 17 to the reformed gas inlet 35 flows through the reformed gas flow-through portion 36 and the end on the opposite side of the cylindrical support 31 (the end provided with the lid portion 34). ) And then flows back toward the gas manifold 17 and flows out from the reaction exhaust gas outlet 37 to the gas manifold 17. The reaction exhaust gas flowing into the gas manifold 17 is mixed with the reformed gas after a predetermined treatment, supplied to the electrochemical element E, and used for the reaction in the electrochemical reaction unit 43.

<Fourth embodiment>
In the first to third embodiments described above, the gas flow allowing portion P2 in the cylindrical support 31 is provided as the perforated region P2 by forming the through hole 38 in the flat plate member 32. And the electrolyte layer 46 was arrange | positioned covering the whole gas flow permission part P2, and the airtight inside and outside of the cylindrical support body 31 was ensured.

  In the fourth embodiment, the gas flow allowing portion P2 is formed by fixing a gas permeable member 61 made of a material having conductivity and gas permeability to an opening 62 provided on the side surface of the cylindrical support 31. The A sealing material 65 that prevents gas leakage from the inside of the cylindrical support 31 is provided at the end of the electrolyte layer 46.

  As shown in FIG. 10, in the cylindrical support 31 according to the fourth embodiment, the gas permeable member 61 is fitted into the opening 62 provided in the flat plate member 32. For the flat plate member 32, a metal or metal oxide having conductivity and gas impermeability, which is the same material as in the other embodiments described above, is used. A material having conductivity and gas permeability is used for the gas permeable member 61. For example, a porous metal or a metal oxide is used. A region where the gas permeable member 61 is fitted in the cylindrical support 31 is a gas flow allowing portion P2, and a region of the flat plate member 32 is a gas flow prohibiting portion P1.

  As shown in FIG. 11, the electrochemical reaction unit 43 according to the fourth embodiment is provided so as to cover a part of the gas permeable member 61. The electrolyte layer 46 of the electrochemical reaction unit 43 covers a part of the gas permeable member 61, covers the entire fuel electrode 44, and covers the entire intermediate layer 45.

  A sealing material 65 is provided at the end of the electrolyte layer 46. The sealing material 65 covers a region of the gas permeable member 61 that is not covered by the electrolyte layer 46, the end faces of the fuel electrode 44 and the intermediate layer 45, and a part of the end face and upper surface of the electrolyte layer 46. As the sealing material 65, a material having insulating properties, gas impermeability, and airtightness is used. For example, a glass sealing material or the like is used. Gas leakage from the inside of the cylindrical support 31 is prevented by the sealing material 65.

<Fifth Embodiment>
In the first to fourth embodiments described above, the electrochemical reaction unit 43 is configured to exhaust the reaction exhaust gas along the axial direction of the cylindrical support 31 so as to promote the electrochemical reaction by making the electrochemical reaction unit 43 as long as possible. It is formed from the end where the outlet 37 is provided to the end where the reformed gas inlet 35 is provided. On the other hand, in the fifth embodiment shown in FIG. 12, the electrochemical reaction unit 43 extends from the end portion where the reaction exhaust gas discharge port 37 is provided along the axial direction of the cylindrical support member 31. It is provided over a length of 4/5 to 5/6 of the axial length.

  Further, in the region from the end where the reformed gas inlet 35 is provided to the length of 1/5 to 1/6 of the axial length of the cylindrical support 31, the gas flow allowing portion P2 and the electric The chemical reaction part 43 is not provided, but the gas flow prohibition part P1 is provided. In other words, in the electrochemical element E according to the fifth embodiment, the length in the axial direction of the cylindrical support 31 is 1/5 to 1/6 from the end where the reformed gas inlet 35 is provided. A non-arrangement region P3 in which the electrochemical reaction part 43 is not provided is provided in the length region. The non-arrangement region P <b> 3 is a region provided on the flat portion of the cylindrical support 31, i.e., the flat plate member 32.

  When the electrochemical element E is attached to the gas manifold 17 (other member), the electrochemical element E and the gas manifold 17 are made of a glass sealing material or the like on the end side where the reformed gas inlet 35 is provided. They are joined by a joining member (also having an insulating member function). That is, among the axial ends of the cylindrical support 31, when the electrochemical element E is attached to another member (gas manifold 17), the fixed end that is the end on the side attached to the other member The non-arrangement region P3 where the electrochemical reaction part 43 is not provided is provided

  The size of the non-arrangement region P3 and the electrochemical reaction portion 43, that is, the length along the axial direction of the cylindrical support 31, considers the temperature when the electrochemical element E is used, the material of the cylindrical support 31, and the like. However, the length of the non-arrangement region P3 is set to 1/5 to 1/6 of the length of the cylindrical support 31, and the length of the electrochemical reaction unit 43 is set to the plane of the cylindrical support 31. Assuming that the length is 4/5 to 5/6, for example, when the electrochemical element E is used as a fuel cell, the tubular support 31 and the gas manifold 17 even if the temperature of the electrochemical reaction unit 43 is about 700 ° C. Therefore, since the heat effect received by the bonded portion from the high temperature electrochemical reaction portion 43 is reduced, the durability of the bonded portion is improved. In addition, since the joining portion has a lower temperature than the electrochemical reaction portion 43, a joining member used for joining the gas manifold 17 and the cylindrical support 31 can be made of a material having a relatively low heat resistance temperature. The attachment of the electrochemical element E to the manifold 17 can be easily performed at low cost.

<Another embodiment>
(1) In the above embodiment, the electrochemical element E operated as a fuel battery cell to generate power. The electrochemical element E may be operated as a solid oxide electrolytic cell (SOEC) that generates hydrogen by electrolyzing water.

(2) As a material of the cylindrical support 31, a conductive metal oxide can also be used. For example, a metal oxide typified by (La, Ca) CrO ₃ (calcium dope lanthanum chromite) can be used.

(3) In the above embodiment, the cylindrical support 31 is configured by bonding the flat plate member 32 and the U-shaped member 33, but may be configured by bonding three or more members. For example, the cylindrical support 31 may be configured as a hollow quadrangular prism by joining four flat plates. Moreover, you may comprise the cylindrical support body 31 from one member. For example, the cylindrical support 31 may be made from a pipe having a circular, quadrangular or elliptical cross section, or from a cylindrical flat plate whose cross section is an ellipse (a cross section formed by two parallel sides and an arc connecting them). It may be configured. Further, the cylindrical support 31 may be formed of an integral material by deep drawing pressing or the like regardless of the joining of the flat plate member 32 and the U-shaped member 33 separately.

(4) In the above embodiment, the electrochemical reaction unit 43 has the fuel electrode 44, the intermediate layer 45, the electrolyte layer 46, the intermediate layer 47, and the air electrode 48, but the intermediate layer 45 or the intermediate layer 47, or A configuration without both the intermediate layer 45 and the intermediate layer 47 is also possible.

  (5) In the above embodiment, the electrochemical reaction unit 43 is arranged outside the cylindrical support 31, but it can also be arranged inside the cylindrical support 31.

  Note that the configurations disclosed in the above-described embodiments (including other embodiments, the same applies hereinafter) can be applied in combination with the configurations disclosed in the other embodiments as long as no contradiction arises. The embodiment disclosed in this specification is an exemplification, and the embodiment of the present invention is not limited to this. The embodiment can be appropriately modified without departing from the object of the present invention.

1: Desulfurizer 4: Reformer 5: Blower (second gas supply unit)
8: Inverter 17: Gas manifold (first gas supply unit, third gas supply unit)
23: Heat exchanger (exhaust heat utilization part)
31: Cylindrical support 32: Flat plate member (plane part)
38: Through-hole 43: Electrochemical reaction part 44: Fuel electrode 45: Intermediate layer 46: Electrolyte layer 47: Intermediate layer 48: Air electrode 61: Gas permeable member 62: Opening part 65: Sealing material E: Electrochemical element E1: 1st electrochemical element E2: 2nd electrochemical element M: Electrochemical module P1: Gas flow prohibition part P2: Gas flow permission part (perforation area)
P3: Non-arrangement area S: Gas supply space

Claims (24)

An electrochemical element having a cylindrical support having conductivity and an electrochemical reaction part,
The electrochemical reaction unit includes a membrane electrolyte layer, a membrane fuel electrode, and a membrane air electrode, and the electrolyte layer is disposed between the fuel electrode and the air electrode,
The cylindrical support includes a gas flow allowing portion that allows gas to flow between the inside and the outside of the cylindrical support, and a gas flow between the inside and the outside of the cylindrical support. A gas flow prohibition section that prohibits flow,
An electrochemical element in which the electrochemical reaction part is disposed outside or inside the cylindrical support so as to cover a part or all of the gas flow allowing part.   The electrochemical device according to claim 1, wherein the cylindrical support is a metal or a metal oxide.   The electrochemical device according to claim 1, wherein the cylindrical support has a flat portion parallel to a central axis of the cylindrical support, and the electrochemical reaction portion is disposed on the flat portion. .   The electrochemical element according to any one of claims 1 to 3, wherein a film-like intermediate layer is disposed between the air electrode and the electrolyte layer.   The electrochemical element according to any one of claims 1 to 4, wherein a film-like intermediate layer is disposed between the fuel electrode and the electrolyte layer.   The electrochemical device according to claim 1, wherein the electrolyte layer is disposed so as to cover the gas flow allowing portion.   The electrochemical element according to any one of claims 1 to 6, wherein a sealing material for preventing gas flow between the inside and the outside of the cylindrical support is provided at an end of the electrolyte layer.   The electrochemical element according to any one of claims 1 to 7, wherein the gas flow allowing portion is a perforated region provided with a plurality of through holes communicating with the inside and the outside of the cylindrical support. .   The said gas flow permission part is formed by fixing the gas permeable member which consists of a material which has electroconductivity and gas permeability to the opening part provided in the side surface of the said cylindrical support body. The electrochemical element of Claim 1.   When the electrochemical element is attached to another member, one of the axial ends of the cylindrical support is fixed to the other member, and the electrochemical element is attached to the other member. The electrochemical device according to claim 1, which is cantilevered.   Among the axial ends of the cylindrical support, when the electrochemical element is attached to another member, the electrochemical reaction portion is fixed to the fixed end that is the end attached to the other member. Or the electrochemical element of any one of Claims 1-10 in which the non-arrangement area | region where the said gas flow permission part is not provided is provided. Among the axial ends of the cylindrical support, when the electrochemical element is attached to another member, the electrochemical reaction portion is fixed to the fixed end that is the end attached to the other member. Alternatively, a non-arrangement region where the gas flow allowing portion is not provided is provided, and an insulating member that electrically insulates the cylindrical support and the other member in any part of the non-arrangement region. The electrochemical device according to any one of claims 1 to 11, which is provided.
  It has two or more electrochemical elements of any one of Claims 1-12, The surface on the opposite side to the said cylindrical support body in the said electrochemical reaction part of one electrochemical element, and other electrochemical A plurality of the electrochemical elements are arranged in parallel in a form in which the cylindrical support bodies of the elements are electrically connected and the axes of the plurality of cylindrical support bodies are parallel to each other. Electrochemical module. The electrochemical element has a gas supply space in which a reaction gas used for a reaction in the electrochemical reaction unit is supplied to a side of the electrochemical reaction unit,
Two adjacent electrochemical elements among the plurality of electrochemical elements arranged in parallel, the first electrochemical element having the electrochemical reaction portion connected to the other electrochemical element, and the tubular shape A second electrochemical element having a support connected to the first electrochemical element;
The gas supply space of the first electrochemical element and the gas supply space of the second electrochemical element communicate with each other via a side of the cylindrical support of the second electrochemical element. 14. The electrochemical module according to 13.   15. A fuel supply unit that includes the electrochemical module according to claim 13 and a reformer and that supplies a fuel gas containing a reducing component to the electrochemical module, and an inverter that extracts electric power from the electrochemical module And an electrochemical device.   An energy system comprising: the electrochemical device according to claim 15; and an exhaust heat utilization unit that reuses heat exhausted from the electrochemical device.   The said fuel electrode is arrange | positioned between the said electrolyte layer and the said cylindrical support body, The 1st gas containing a reducing component is supplied to the inside of the said cylindrical support body. The electrochemical device according to Item.   A plurality of the electrochemical elements according to claim 17, a surface of the electrochemical reaction part of one electrochemical element opposite to the cylindrical support, and the cylindrical support of another electrochemical element And an electrically connected module, and a plurality of the electrochemical elements are arranged in parallel so that the axes of the plurality of cylindrical supports are parallel to each other.   It has a 1st gas supply part which supplies said 1st gas containing a reducing ingredient inside a cylindrical support of a plurality of said electrochemical elements, and said cylindrical support among the edge parts of said electrochemical elements The electrochemical module according to claim 18, wherein one end portion in the axial direction is connected to the first gas supply unit.   20. The electrochemical module according to claim 18, further comprising a second gas supply unit configured to supply a second gas containing an oxidizing component to the electrochemical reaction unit from the outside of the cylindrical support.   The said air electrode is arrange | positioned between the said electrolyte layer and the said cylindrical support body, The 3rd gas containing an oxidizing component is supplied to the inside of the said cylindrical support body. The electrochemical device according to Item.   A plurality of the electrochemical elements according to claim 21, a surface of the electrochemical reaction part of one electrochemical element opposite to the cylindrical support, and the cylindrical support of another electrochemical element; An electrochemical module in which a plurality of the electrochemical elements are arranged in parallel with each other in a form in which the axes of the plurality of cylindrical supports are parallel to each other.   A cylindrical support for supplying the third gas containing an oxidizing component inside the cylindrical support for the plurality of electrochemical elements; and the cylindrical support among the ends of the electrochemical elements. The electrochemical module according to claim 22, wherein one end in the axial direction is connected to the third gas supply unit.   The electrochemical module according to claim 22 or 23, further comprising a fourth gas supply unit configured to supply a fourth gas containing a reducing component to the electrochemical reaction unit from the outside of the cylindrical support.

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