JP5157085B2 - Solid oxide fuel cell - Google Patents

Description

  The present invention relates to a solid oxide fuel cell such as a fuel cell or an oxygen enricher utilizing an electrochemical action of a solid electrolyte having hydrogen ion conductivity or oxygen ion conductivity.

  A fuel cell that generates electricity by supplying air and hydrogen to both electrodes of a hydrogen ion conductive or oxygen ion conductive solid electrolyte has recently attracted attention from the viewpoint of resource saving and environmental protection. These fuel cell systems are solid-electrolyte electrochemical devices that electrochemically react oxygen and hydrogen to convert their chemical energy into electrical energy. The power generation efficiency is improved by preheating and supplying the high-temperature fluid heated by the heat generating means. There are various examples of solid electrolyte type electrochemical devices in which a heat exchanger is mounted on a fuel cell using such an ion conductive solid electrolyte.

  FIG. 5 is a partially exploded perspective view of a fuel cell which is an example of the conventional solid electrolyte electrochemical device. The fuel cell system is equipped with a heat exchanger in which a plurality of flat plates are stacked, and has an advantage of a compact structure and a small installation area (see, for example, Patent Document 1). This apparatus includes an air heat exchanger 3 including four stacked heat exchange plates 1a, 1b, 1c, and 1d and a separator 2, and a combustion battery 4. The separator 2, the first heat exchange plate 1 a, the second heat exchange plate 1 b, the third heat exchange plate 1 c, and the fourth heat exchange plate 1 d have substantially the same shape and size, and oppose each arrangement. And two holes for communicating with each other, and two holes for communicating with each other. The holes include supply holes 5s, 5a, 5b, 5c and 5d through which low-temperature fuel gas before use passes, and exhaust holes 6s, 6a, 6b, 6c and 6d through which high-temperature fuel gas after use passes, The through holes 7s, 7a, 7b, 7c, 7d through which the low-temperature air before use passes, and the through holes (II) 8s, 8a, 8b, 8c, 8d through which the high-temperature air after use passes.

  The separator 2 includes a through hole 7s for introducing low-temperature air before use and a through-hole (II) 8s through which high-temperature air after use passes. In addition, the first heat exchange plate 1a allows through-holes 7a for introducing low-temperature air before use, through-holes (II) 8a through which high-temperature air after use passes, and low-temperature air flowing from the through-holes 7a. Is provided with a recess 9a provided on the surface. Further, the second heat exchange plate 1b has a through-hole 7b for introducing low-temperature air before use, a through-hole (II) 8b through which high-temperature air after use passes, and a recess 9b for allowing the flowing high-temperature air to pass through. I have. Hereinafter, the third heat exchange plate 1c and the fourth heat exchange plate 1d are similarly provided with through holes 7c, 7d, through holes (II) 8c, 8d, and recesses 9c, 9d.

  The through hole (II) 8s of the separator 2 is opened in opposition to the arrangement of the through hole (II) 8a of the first heat exchange plate 1a and the end of the upper recess 9b of the second heat exchange plate 2b. The high-temperature air after use forms an air flow through the through holes (II) 8s through 8a and further through the recesses 9b. And the flow of this high temperature air flows out from 8d via the through-holes (II) 8b, 8c, and the dent 9d. The through hole 7d of the fourth heat exchange plate 1d is opened against the through hole 7c located at the end of the recess 9c of the third heat exchange plate 1c, and low-temperature air before use passes through the through hole 7d. 7c and an air flow passing through the recess 9c are formed. And the flow of this low temperature air flows out from 7s via 7a and the dent 9a from the through-hole 7b. By this flow, for example, heat exchange between the low-temperature air flowing through the recess 9d and the high-temperature air flowing through the recess 9c is performed between the lower surface of the third heat exchange plate 1c.

  As another example, a heat exchanger is arranged in the air flow path to the air electrode of the fuel cell system, and heat generated in the combustor is transferred to room temperature air supplied to the air electrode to reduce stress. There is also an example of improving durability reliability. (For example, refer to Patent Document 2).

Next, a heat exchanger having a structure in which a plurality of plates is laminated will be described. For example, a primary-side channel partition plate having a channel groove and a through hole through which the primary fluid flows on one side, and a channel groove and a through-hole having substantially the same shape and through which the secondary side fluid flows on one side. A laminated heat exchanger in which a plurality of secondary flow path partition plates are stacked as one set has an advantage of low flow path pressure loss (see, for example, Patent Document 3). Furthermore, the laminated heat exchanger in which a plurality of heat exchange elements including one or more communication portions and a hollow portion are opposed to each other at a predetermined interval and the communication portions are joined is small and has excellent heat transfer performance. There is an advantage (see, for example, Patent Document 4).

Furthermore, there is a proposal of a solid electrolyte type electrochemical device that is an oxygen enriched device in which an oxygen concentration is increased using an oxygen ion conductive solid electrolyte (see, for example, Patent Document 5). In this apparatus, a voltage of several volts is applied to a first electrode and a second electrode formed on both surfaces of an oxygen ion conductive solid electrolyte by a DC power source, and oxygen molecules are transferred from the first electrode to the oxygen ion conductive solid electrolyte. An electrochemical element that generates 100% oxygen gas on the second electrode side by moving to the second electrode is formed. The electrochemical element is partitioned into a space on the first electrode side and a space on the second electrode side by partition means attached via an adhesive material. In addition, in order to effectively perform the electrochemical reaction of oxygen generation, a heater for heating the electrochemical element is disposed, and heat is generated by energization and the temperature is raised to about 600 ° C. Yes. The surroundings of the electrochemical element, partitioning means, and heater are encased with a breathable heat insulating material, and the circumference is encased with a casing provided with an opening to reduce heat dissipation, thereby reducing the power of the heater. . Since the electrochemical element and the heater are prevented from coming into direct contact with the atmosphere by a breathable heat insulating material, the thermal efficiency of the heater to the electrochemical element is improved, and the power consumption required for heating the electrochemical element is reduced. can do. In addition, since the partition means for simultaneously holding the electrochemical element is composed of an iron-chromium alloy metal foil having substantially the same thermal expansion coefficient, the electrochemical element is held elastically, and the heat insulating material In combination with the synergistic effect, a uniform temperature distribution can be obtained, and crack breakage due to a temperature difference can be prevented.
JP-A-7-176315 JP 2005-166439 A JP-A-9-292194 JP 2000-205768 A JP 2003-215094 A

  However, in the solid electrolyte type electrochemical device used as the fuel cell system of Conventional Example 1, the heat exchanger has a configuration in which a plurality of flat heat exchange plates each having a dent on the surface are stacked, so that a dent is formed on the surface. However, there was a problem that a heat exchanger had to be manufactured with a complicated manufacturing method and strict quality control. Moreover, since the solid electrolyte type electrochemical device used as the fuel cell system of Conventional Example 2 uses a heat exchanger having a general configuration, there is a problem that the device becomes large. Furthermore, since the heat exchanger of Conventional Example 3 has a configuration in which a plurality of flow channel partition plates having a flow channel groove and a through hole through which a fluid flows on one side are laminated, a complicated manufacturing method and a strict process are required for forming a groove on the surface. There was a problem that required quality control. Furthermore, the heat exchanger of Conventional Example 4 has a complicated structure because a plurality of thermal elements having one or more communicating portions and a hollow portion are opposed to each other at a predetermined interval and the communicating portions are joined. There was a problem that had to be manufactured by manufacturing method and strict quality control.

On the other hand, the conventional solid-electrolyte type electrochemical device as an oxygen-enriching device of conventional 5 radiates heat by enclosing the periphery of the electrochemical element, the partition means and the heater with a breathable heat insulating material in order to reduce the power required for heating. Since it is the structure which aims at reduction | restoration, when the oxygen generation capability enlarged, the subject that the power consumption of a heater was not reduced as expected had occurred. This is because when the oxygen generation capacity increases, a large amount of air supply needs to be replenished, and in order to make this large amount of air supply replenishment smooth, there is a need to actively increase the air permeability of the heat insulating material. However, as a result, the heat insulation performance is lowered and the temperature of the electrochemical element is lowered. To prevent this, the electric power of the heater is increased. This is because the electrochemical element is maintained at a predetermined temperature. In other words, the electrochemical element and the heater in the conventional solid electrolyte type electrochemical device are configured not to come into direct contact with the atmosphere by a breathable heat insulating material. This configuration can cope with the supply replenishment, but if the oxygen generation and concentration capacity is increased, a large amount of air supply replenishment is required, so that the heat insulating material prevents the air supply replenishment. For this reason, if the conventional heat insulation structure is used as it is to improve the oxygen generation capacity, it is necessary to positively increase the air permeability by reducing the thickness of the heat insulating material, which increases the power consumption of the heater. Was invited.

  The present invention solves the above-mentioned problems, and by using a small heat exchanger that can be manufactured with a simple manufacturing method and quality control, the structure is reduced to a compact structure, and the ion conductive solid electrolyte is reduced. An object of the present invention is to provide a solid oxide fuel cell that reduces power consumption such as a heating element that heats the heating element.

In order to solve the conventional problem, an electrochemical element having a cathode electrode and an anode electrode formed on both surfaces of an ion conductive solid electrolyte, a cathode side space in which inflow air contacting with the electrochemical element is retained, and Partitioning means for partitioning an anode side space in which an anode electrode in which oxygen contained in the inflowing air reaches oxygen ions via the ion conductive solid electrolyte is disposed, and an electric heater for heating the electrochemical element And a heat exchanger that heats the inflow air using exhaust gas discharged from the cathode side space and supplies the heated inflow air to the cathode side space, and the heat exchanger includes: A substantially flat first heat exchange plate having a first flow path through which inflow air passes; a substantially flat second heat exchange plate having a second flow path through which the exhaust gas passes; The first flow path and the second flow path are arranged so as to be stacked through a substantially flat third heat exchange plate and heat exchange is performed in the stacking direction. The solid oxide fuel cell is disposed in a cathode space between a vessel and the electrochemical element, and is disposed so as to face the cathode electrode of the electrochemical element and the heat exchange plate of the heat exchanger. .

  The heat exchanger has a structure in which a plurality of substantially flat heat exchange plates having at least two fluid passage gaps are stacked as constituent members, so that the inflowing air and the high-temperature fluid pass through the structure. Since two types of bent flow paths can be formed, it can be manufactured with a simple manufacturing method and quality control. Moreover, since the heat exchanger is a structure in which substantially flat heat exchange plates are stacked, the size is reduced, and a solid electrolyte type electrochemical device using the heat exchanger has a compact structure and a small volume. Further, the heat exchanger is disposed in the internal space of the cathode side space or in the joint space leading to the internal space, and the inflow air supplied to the cathode electrode of the electrochemical element is heated to the heat of the high-temperature fluid discharged from the outlet portion. Therefore, the power consumption of a heating body for heating an electrochemical element made of an ion conductive solid electrolyte can be reduced.

  INDUSTRIAL APPLICABILITY The present invention can provide a solid oxide fuel cell that is compact and has a small volume and reduced power consumption for heating by using a small-sized heat exchanger that can be manufactured by a simple manufacturing method and quality control. .

A solid oxide fuel cell according to a first aspect of the present invention is an electrochemical device having a cathode electrode and an anode electrode formed on both surfaces of an ion conductive solid electrolyte, and a cathode side space in which inflow air contacting with the electrochemical device stays. Partitioning means for partitioning an anode side space in which an anode electrode in which oxygen contained in the inflowing air reaches oxygen ions as oxygen ions via the ion conductive solid electrolyte , and heating the electrochemical element An electric heater and a heat exchanger that heats the inflow air using exhaust gas discharged from the cathode side space and supplies the heated inflow air to the cathode side space, A substantially flat first heat exchange plate having a first flow path through which the inflow air passes, and a substantially flat second heat exchange plate having a second flow path through which the exhaust gas passes. Are arranged via a substantially flat third heat exchange plate, and the first flow path and the second flow path are arranged so that heat exchange is performed in the stacking direction. A solid oxide fuel cell disposed in a cathode space between a heat exchanger and the electrochemical element, and disposed to face a cathode electrode of the electrochemical element and a heat exchange plate of the heat exchanger It was.

  Since the heat exchanger is a laminated structure of substantially flat plate-like heat exchange plates, the heat exchanger becomes small, and a solid electrolyte type electrochemical device using the heat exchanger has a compact structure and a small volume.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, this invention is not limited by the form of this invention.

(Embodiment 1)
FIG. 1 is a configuration diagram of a solid electrolyte electrochemical device according to Embodiment 1 of the present invention. It is a block diagram in the case of using an oxygen ion conductive solid electrolyte that conducts oxygen as oxygen ions as an ion conductive solid electrolyte and using it as an oxygen enrichment device that increases the oxygen concentration. When the cathode electrode 14 and the anode electrode 15 are formed on both surfaces of the ion conductive solid electrolyte 13, the ion conductive solid electrolyte 13 becomes an electrochemical element 16 in which oxygen molecules move as oxygen ions therein. The electrochemical element 16 is heated up to about 500 to 900 ° C. by a heating body 17 such as a heater arranged opposite to the electrode on one side, and a voltage of several volts is applied by a DC power source (not shown). Then, oxygen molecules in the air move from the cathode electrode 14 to the anode electrode 15 through the oxygen ion conductive solid electrolyte 13, and 100% oxygen gas is generated on the anode electrode 15 side. The electrochemical element 16 is divided into a space on the cathode electrode 14 side (hereinafter referred to as a cathode side space) 19 and a space on the anode electrode 15 side (hereinafter referred to as an anode side space) 20 by the partition means 18. It is partitioned so that the produced 100% oxygen gas can be obtained with high purity without being mixed with air.

  In the cathode side space 19 or the anode side space 20, the heating body 17 is arranged in one or both of the internal spaces or in a space jointly connected to these spaces, and the surroundings are surrounded by a heat insulating material 21. The partition means 18 is a member made of a metal or ceramic having substantially the same thermal expansion coefficient as that of the ion conductive solid electrolyte 13 (same within ± 20%), and an electrically insulating joint disposed in a part thereof. The ion conductive solid electrolyte 13 is held via the material 22.

  The heat exchanger 23 is disposed in the internal space of the cathode side space 19 or in a space jointly connected thereto, and has a substantially flat plate shape having at least a fluid passage space 24 (for inflowing air) and 25 (for high temperature fluid). The heat exchange plate 26 is laminated as a main component to form a bent flow path (inflow air side) 29 through which inflow air passes and a bent flow path (high temperature fluid side) 30 through which high temperature exhaust gas passes. It is a structure. The air flows from the inlet 27 of the heat exchanger 23, passes through the bent flow path (inflow air side) 29, flows into the cathode-side space 19, and heats the heated electrochemical element 16 and heating body 17. Then, it is discharged from the outlet portion 28 via the bent channel (high temperature fluid side) 30. At that time, in the bent flow path (inflow air side) 29 and the bent flow path (high temperature fluid side) 30, the exhaust gas heat is transferred to the inflow air from the inlet portion 27 to reduce the power consumption of the heating element 17. Reduce.

The materials and configuration used in the oxygen enrichment apparatus in which the oxygen concentration is increased using an oxygen ion conductive solid electrolyte will be described. The oxygen ion conductive solid electrolyte body 13 is a ceramic that conducts oxygen ions, and is a zirconia composite metal oxide in which ₃ to 15 mol% of Y ₂ O ₃ , CaO, or the like is dissolved in 97 to 85 mol% of ZrO _{2. things, (La 0.8 Sr0 .2) (} Ga 0.8 Mg 0.15 Co 0.05) O 3- δ and LaGaO lanthanum gallate de-based composite metal oxide such as _{3, (Ba, Sr, La} ) ₂ (In _1-x Yx) ₂ O _Y defect perovskite complex oxide is used. These are materials having a thermal expansion coefficient of 9 to 11 × 10 ⁻⁶ / ° C., but the lanthanum garade composite metal oxide is excellent in oxygen ion conductivity and has a black color. There is an advantage that it is excellent in the characteristic of absorbing infrared rays emitted from 17.

The cathode electrode 14 and the anode electrode 15 are a metal oxide-based electrode mainly composed of an oxygen-deficient structure or a perovskite structure or both metal oxides, a noble metal electrode mainly composed of a noble metal, or these metal oxide-based electrodes. Any of the laminated electrodes in which a noble metal electrode is further laminated on the substrate. An oxygen-deficient structure metal oxide is a metal oxide expressed by a chemical formula in which the number of oxygen molecules is insufficient in terms of stoichiometry, and a perovskite structure metal oxide is composed of an A metal, a B metal, and oxygen. It is a complex metal oxide whose chemical formula is expressed as ABO ₃ . Specifically, the metal oxide based electrodes are LaCo ₃ , SmSrCox, (La _0.6 Sr _0.4 ) (Co _0.2 Fe _0.8 ) O ₃ , (Sr _0.10 Ce _0.01 ). Zr _0.89 O ₂ , (La _0.6 Sr _0.4 ) MnO _{3 -δ} , (La _1-x Srx) CoO _{3 -δ} are used. The noble metal electrode is a single component of platinum, palladium, gold, silver, silver, rhodium, iridium, or ruthenium or a plurality of these components. If necessary, bismuth oxide may be further mixed in an amount of 1 to 6 wt%. The metal oxide-based electrode is a metal oxide having a good adsorption / desorption property of oxygen molecules, and improves the adhesion with the oxygen ion conductive solid electrolyte body 13 to increase the oxygen ion conductivity. In addition, when a laminated electrode in which a noble metal electrode is further laminated on a metal oxide electrode for the purpose of improving electric conductivity, there is an advantage that oxygen ion conductivity is further increased, and it is optimal for electrochemical applications.

  The heating element 17 is an electric heater using an iron-nickel alloy or a nickel-chromium alloy, and emits a lot of infrared rays. Although it is desirable that the heating element 17 is disposed close to the one-side electrode of the electrochemical element 16 so that the electrochemical element 16 can receive as much heat and infrared rays as possible, it ensures electrical insulation. For this reason, when the electrical insulating film is inevitably disposed between the two, the film thickness is made as thin as possible so that the electrochemical element 16 can receive a large amount of heat and infrared rays emitted from the heating body 17. When the heating element 17 is disposed in the cathode side space 19, it is exposed to a gas having an oxygen concentration equal to or lower than that of the atmosphere, so that the material deterioration due to oxygen is reduced and the durability reliability is improved. Therefore, there is an advantage that inexpensive general-purpose materials can be used sufficiently. On the other hand, when the heating element 17 is disposed in the anode side space 20, it is exposed to an environment having a higher oxygen concentration than the atmosphere, and therefore, it is necessary to use an expensive material having excellent oxidation resistance from the viewpoint of preventing material deterioration due to oxygen. Occurred.

  The heat insulating material 21 is a material mainly composed of silica or alumina alone or a composite. In the first embodiment, the cathode side space 19 that encloses the electrochemical element 16 and the heating body 17, and further the anode side space 20. Since it has the structure which encloses, it is trying to have heat dissipation suppression property.

The partitioning means 18 is a metal or ceramic that has no air permeability, and surrounds the cathode electrode 14 and the anode electrode 15 with these materials, thereby partitioning the cathode side space 19 and the anode side space 20. A part of the partition means 20 holds the oxygen ion conductive solid electrolyte 13 constituting the electrochemical element 16 via an electrically insulating bonding material 22 made of glass or ceramic. For this reason, the partition means 18 uses a plate or foil of a metal material having the same thermal expansion coefficient as that of the oxygen ion conductive solid electrolyte 13 (same within ± 20%). Specifically, since the thermal expansion coefficient of the oxygen ion conductive solid electrolyte 13 is 9 to 11 × 10 ⁻⁶ / ° C., the holding plate 22 is iron having a thermal expansion coefficient within ± 20%. A chromium-based alloy is a ferritic stainless steel and a nickel-based alloy mainly composed of nickel. In particular, the iron-chromium alloy is approximately the same as the oxygen ion conductive solid electrolyte 13 with a thermal expansion coefficient of 10.4 × 10 ⁻⁶ / ° C. when SUS430 containing iron as a main component and containing 18 wt% chromium is taken as an example. It was optimal because it had the advantage that the ultra-thin film of chromium oxide or iron oxide was formed on the surface by high-temperature firing and the infrared absorption was increased. The electrically insulating bonding material 22 is composed of the oxygen ion conductive solid electrolyte 13.
Therefore, glass, crystallized glass, and ceramic having the same thermal expansion coefficient as those (within ± 20%) are used. The electrically insulating bonding material 22 made of these materials is applied to the periphery of a through hole provided in advance in the partitioning means 18, and the periphery of the end of the electrochemical element 16 is laminated on the upper portion and fired at a high temperature to bond Ensure electrical properties and electrical insulation. Further, the electrochemical element 16 uses a large number of small elements having a small area, and is arranged and held in the partition means 18 made of a single large-area metal foil, thereby improving the ability to move oxygen molecules. The durability and reliability were improved.

  The heat exchanger 23 is mainly composed of a plurality of heat exchange plates 26 such as a ferritic stainless steel plate in which fluid passage gaps 24 (for inflowing air) and 25 (for high temperature fluid) are formed in advance. Then, a plurality of heat exchange plates 26 are laminated to form a bent flow path (inflow air side) 29 through which inflow air passes and a bent flow path (high temperature fluid side) 30 through which high temperature exhaust gas passes. As a component of things. It is arranged in parallel with the internal space of the cathode side space 19, and heat exchange is performed in the bent flow path (incoming air side) 29 and the bent flow path (high temperature fluid side) 30 provided in the middle of the inlet portion 27 and the outlet portion 28. Then, the high-temperature exhaust gas heat from the heated electrochemical element 16 and the heating body 17 is transferred to the inflow air.

This solid-electrolyte electrochemical device was prototyped and the effect was confirmed. Electrochemical device _{16, (La 0.8 Sr0 .2) (} Ga 0.8 Mg 0.15 Co 0.05) O 3- oxygen ion conductive solid electrolyte made of lanthanum gallate de-based composite metal oxide of _δ In this configuration, a cathode electrode 14 and an anode electrode 15 are formed on both surfaces of the body 13 by laminating a gold noble metal electrode on top of a (La _1-x Srx) CoO _{3 -δ} metal oxide electrode. The partition means 18 is a ferritic stainless steel foil and is provided with a large number of through holes. The peripheral part of the through hole provided in the partition means 18 is coated with an electrically insulating bonding material 22 made of glass by using a thick film printing method, and the periphery of the end part of the small-area electrochemical element 16 on the upper part. Each was laminated and baked at 900 ° C. to ensure the seal bonding property and electrical insulation between them. A heating body 17 of an electric heater is disposed in the vicinity of a partition means 18 that holds a large number of electrochemical elements 16. These parts are surrounded by a heat insulating material 21 mainly composed of a composite of silica and alumina.

  The heat exchanger 23 is mainly a member in which a plurality of substantially flat plate-shaped heat exchange plates 26 made of ferritic stainless steel having gaps 24 (for inflowing air) and 25 (for high temperature fluid) through which gas passes are laminated. This forms two bent flow paths through which the incoming air and the high temperature exhaust gas pass, that is, a bent flow path (inflow air side) 29 and a bent flow path (high temperature fluid side) 30. doing. Therefore, it could be manufactured with a simple manufacturing method and simple quality control. Further, since the heat exchanger 23 is a structure in which a substantially flat heat exchange plate 26 is laminated, the solid electrolyte type electrochemical device using the heat exchanger 23 has a compact structure and a small volume. Furthermore, since the high temperature exhaust gas heat from the heated electrochemical element 16 and the heating body 17 is transferred to the inflow air, the power consumption of the heating body 17 is lower than that of a conventional product without a heat exchanger. It was reduced by 1.5%.

  The two fluid passage gaps (for inflow air) 24 and the fluid passage gap (for high temperature fluid) 25 formed in the heat exchange plate 26 and the two bent flow paths (for inflow air) formed therein The number 29 and the bent flow path (for high temperature fluid) 30 need not be limited to two, and may be two or more depending on the application. Also, the number of heat exchange plates 26 is not limited depending on the application.

This solid electrolyte type electrochemical device can be used as a fuel cell using the oxygen ion conductive solid electrolyte 13 in addition to the use of the oxygen concentrator. In this case, since the cathode electrode 14 becomes an air electrode, a single electrode of a metal oxide based electrode mainly composed of an oxygen-deficient structure, a perovskite structure, or both metal oxides, or a noble metal laminated thereon is mainly used. It corresponded using the laminated electrode with the noble metal electrode as a component. Further, since the anode electrode 15 is a fuel electrode, nickel oxide or a mixed electrode of nickel was used. Moreover, the heating body 17 was arrange | positioned in the cathode side space 19 and the anode side space 20 as a structure body of the stainless steel metal cylinder which combustion exhaust gas passes the inner space. The heat exchanger 23 comprises a heat exchange plate 26 made of a metal such as stainless steel, and is used to heat room temperature air flowing into the cathode electrode 14 by exchanging heat with a high-temperature gas discharged from the cathode electrode 14, and flowing into the cathode electrode 14. The room temperature air used was used for heating by exchanging heat with the high-temperature gas discharged from the combustion exhaust gas.

  Moreover, it can also be used as a fuel cell using the ion conductive solid electrolyte 13 which conducts hydrogen ions. In that case, the ion conductive solid electrolyte 13 was handled using a sulfonated fluoropolymer. The cathode electrode 14 and the anode electrode 15 corresponded using a noble metal such as platinum. Moreover, the heating body 17 was arrange | positioned in the space which adjoined the cathode side space 19 and the anode side space 20, or these spaces as a structure of metal cylinders, such as stainless steel through which the hot water passes. The heat exchanger 23 comprises a heat exchange plate 26 made of a metal such as resin or stainless steel, and is used for heating or heating / humidifying the room temperature air flowing into the cathode electrode 14 by exchanging heat with a hot water fluid, and flowing into the cathode electrode 14. It was used as an application in which room temperature air was heated by heat exchange with a high-temperature gas discharged from combustion exhaust gas. For example, in the case of heating and humidifying the room temperature air flowing into the cathode electrode 14 by heat exchange with a hot water fluid, heat having four fluid passage gaps using a film-like thin film through which moisture passes as a heat transfer body. The exchange plate A and the heat exchange plate B having four fluid passage gaps were used as a structure that was appropriately laminated and fastened with a convex or flat outer peripheral sealing material interposed therebetween.

(Embodiment 2)
In the second embodiment, the configuration for arranging the heat exchanger 23 in the solid electrolyte type electrochemical device with high heat exchange efficiency is examined. As shown in FIG. 1, the heat exchanger 23 is provided on a heat exchange plate 26 at the outermost part thereof, and fluid passage gaps 24 (for inflowing air) and 25 through which air inflow and high temperature gas discharge respectively pass. (For high temperature fluid) is provided opposite to the cathode side space 19 of the solid electrolyte type electrochemical device. Therefore, the high-temperature exhaust gas heat flowing out from the cathode side space 19 can effectively transfer heat to the room temperature air flowing into the space 19, and the solid electrolyte type electrochemical device of this configuration has a high heat exchange with the heat exchanger 23. The advantage of having an efficiency arises and the effect of reducing the power consumption of the heating body 17 by 20% compared with the conventional product without a heat exchanger has arisen.

(Embodiment 3)
Embodiment 3 is the content of examining a configuration for arranging the heat exchanger 23 with high heat exchange efficiency in a solid electrolyte electrochemical device. As shown in FIG. 1, in the heat exchanger 23, two fluid passage gaps 24 (for inflow air) and 25 (for high temperature fluid) are arranged at substantially the end of the heat exchange plate 26 at the outermost part. In addition, if it is provided opposite to the cathode side space 19 of the solid electrolyte type electrochemical device, the high-temperature exhaust gas heat flowing out from the cathode side space 19 can transfer heat to the flowing room temperature air more effectively. Therefore, the solid electrolyte type electrochemical device configured as described above has an advantage that the heat exchanger 23 has higher heat exchange efficiency, and the power consumption of the heating element 17 is reduced as compared with the conventional product without the heat exchanger. The effect of reducing by 2.5% occurred.

(Embodiment 4)
In the fourth embodiment, the configuration for arranging the heat exchanger 23 with high heat exchange efficiency in the solid electrolyte type electrochemical device is examined. As shown in FIG. 1, a substantially end portion of the heating body 17 arranged in the cathode side space 19 is a fluid passage gap portion 24 (for inflowing air) provided in a heat exchange plate 26 on the outermost side of the heat exchanger 23. ) And 25 (for high-temperature fluid), the high-temperature exhaust gas heat flowing out from the heating body 17 can effectively transfer heat to the flowing room temperature air. For this reason, the heat exchanger 23 configured as described above has an advantage of further higher heat exchange efficiency. The solid electrolyte type electrochemical device having this configuration has the advantage that the heat exchanger 23 has high heat exchange efficiency, and the power consumption of the heating element 17 is reduced by 30% compared to the conventional product without the heat exchanger. The effect to do.

(Embodiment 5)
In the fifth embodiment, the structure of the heat exchanger 23 used in the solid electrolyte type electrochemical device of the present invention is further studied. The structure of the studied heat exchanger is shown in FIG.

  The heat exchanger 23a is a substantially flat ferritic stainless steel heat exchange plate 26a in which fluid passage gaps 24a to 24e (for inflowing air) and 25a to 25e (for high temperature fluid) are arranged at least at substantially ends. , 26b, 26c, 26d, and 26e are main structural members. Each of the heat exchange plates 26a to 26e is bonded with a brazing material, and fluid passage gaps (for inflowing air) 24a, 24b, 24c, 24d, 24e and fluid passage gaps (for high temperature fluid) 25a, 25b. , 25c, 25d, and 25e are disposed at least at substantially the end portions, respectively. And the bending flow path (inflow air side) 29 is formed by arrange | positioning the fluid passage space | gap part (for inflow air) 24a-24e in communication. Further, the bent flow passage (high temperature fluid side) 30 is formed by arranging the fluid passage gap portions (for high temperature fluid) 25a to 25e in communication with each other. The outermost heat exchange plate 26a has an inlet portion 27 and an outlet portion 28 arranged substantially perpendicular to the flat plate direction.

  Since the fluid passage gaps (for inflowing air) 24a to 24e and the fluid passage gaps (for high temperature fluid) 25a to 25e are arranged at at least substantially end portions of the respective heat exchange plates 26a to 26e, the bending flow The passage (for inflowing air) 29 and the bent passage (for high temperature fluid) 30 are effectively arranged for heat exchange, and high heat exchange efficiency can be obtained. In addition, since a structure in which a plurality of substantially flat heat exchange plates 26a to 26e are stacked is a main constituent member, a heat exchanger having a compact structure can be manufactured by a simple manufacturing method and quality control.

(Embodiment 6)
The sixth embodiment is the content of further study on the configuration of the heat exchanger 23, and the configuration of the studied heat exchanger is shown in FIG. The difference from FIG. 2 is that heat exchange plates 26b to 26e in which fluid passage gaps 24b to 24e (for inflowing air) and 25b to 25e (for high temperature fluid) are formed in the internal space 32 of the casing 31 in advance. This is the point of the arranged structure. Since the heat exchange plates 26b to 26e can be fixed by being press-fitted into the internal space 32 of the housing 31 or supported by a spring material, the fixing can be simplified.

(Embodiment 7)
In the seventh embodiment, the structure of the heat exchanger 23 used in the solid electrolyte electrochemical device of the present invention is further examined, and the structure is shown in FIG. The difference from the sixth embodiment is that an inlet portion 27 and an outlet portion 28 are arranged substantially perpendicular to the flat plate direction at the bottom of the housing 31. Since the inlet portion 27 and the outlet portion 28 are disposed substantially perpendicular to the bottom of the casing 31, the fluid passage gap portions (for inflowing air) 24b to 24e and the fluid passage gap portions (for high temperature fluid) 25b to 25e is an effective arrangement for heat exchange, and high heat exchange efficiency is obtained. Moreover, it becomes a heat exchanger with a compact structure and can be manufactured with simple manufacturing method and quality control.

(Embodiment 8)
In the eighth embodiment, the structure of the stacked heat exchanger is further studied, and the structure is shown in FIG. The difference from FIG. 2 and FIG. 3 is that a heat transfer plate provided with moisture permeable films 33o, 33p, 33q, and 33r in the central portion is a heat exchange plate that is non-moisture permeable and plays the role of a frame. 26i, 26j, 26k, 26l, and 26m. And, for example, a laminated type is used so that warm water is humidified from a bent flow path (for hot water of high-temperature fluid) 30 to a bent flow path (for inflow air) 29 of room temperature air via a moisture-permeable film 33o. A heat exchanger 23c is configured.

  For example, a fluid passage gap (for inflowing air) 24i is arranged in the heat exchange plate 26i to form a bent flow path (for inflowing air) 29, and a fluid passage gap 25j (for hot water of high-temperature fluid) is formed in the heat exchange plate 26j. ) To form a bent flow path (for hot water of high-temperature fluid) 30, each of the heat exchange plates 26 i to 26 m is provided with a fluid passage gap (not numbered) in each of these 2 A kind of bent channel is formed.

  Room temperature air flows in from the inlet 27x and contacts the moisture-permeable film 33o via, for example, a bent flow path (for inflowing air) 29. On the other hand, the hot water flows in from the inlet 27y, and contacts the moisture permeable film 33o via, for example, the bent flow path (for hot water of high-temperature fluid) 30. For example, heat transfer and moisture humidification are performed from the warm water toward the air through the moisture permeable film 33o, and the air becomes humidified warm air. This heat transfer and moisture humidification are also performed through the other moisture-permeable films 33p to 33r, and air that has become humidified warm air flows out from the outlet 28x and cooled water flows out from the outlet 28y.

  In order to perform this fluid flow smoothly, two fluid passages through which air flows at room temperature pass through a heat-transfer heat exchange plate provided with moisture-permeable films 33o to 33r and non-moisture-permeable heat exchange plates 26i to 26m. A gap (one is shown, the other is not shown) and two fluid passage gaps (one is shown, the other is not shown) through which hot water flows are formed on each plate. did. Each of these two fluid passage gaps is composed of an opening and a branch passage communicating with the opening. Furthermore, each heat exchange plate is laminated with a rubber and elastomer convex outer periphery sealing material 34 (a representative example is indicated by a number and the others are not indicated), and has an inlet portion 27x and an outlet portion 28y. A heat exchange plate 26h and a heat exchange plate 26n having an inlet portion 27y and an outlet portion 28x were arranged on both sides, and finally, the plate was fastened with a fastening material (not shown) and held under pressure. Thus, the bent flow path through which room temperature air flows is a flow path such as 29 that performs heat transfer and moisture humidification through the moisture permeable film, and the air flows in and out through various heat exchange plates. A 29x flow path is formed. Similarly, the bent flow path through which the hot water flows is a flow path such as 30 that performs heat transfer and moisture humidification through the moisture-permeable film, and 30x that flows in and out of the warm water through various heat exchange plates. A flow path like this is formed. With these things, the stacked heat exchanger 23c, which is small in size, can be manufactured by a simple manufacturing method and quality control. In addition, although the material composition which sulfonated the fluorine polymer was used for the moisture permeable films 33o-33r, since this material is also a hydrogen ion conductive solid electrolyte, such a hydrogen ion conductive solid electrolyte is used. You may do it.

(Embodiment 9)
In the ninth embodiment, in order to effectively use the stacked heat exchanger 23c of the eighth embodiment, application to a solid electrolyte type electrochemical device such as a fuel cell using a hydrogen ion conductive solid electrolyte is examined. The contents are shown in FIG. The stacked heat exchanger 23c is disposed on the upstream side of the cathode electrode 14 so that warmed air containing a lot of high-temperature moisture is supplied to the cathode electrode 14 of the hydrogen ion conductive solid electrolyte 35. This solid electrolyte type electrochemical device is obtained by reacting hydrogen moving from the anode electrode 15 to the cathode electrode 14 via the hydrogen ion conductive solid electrolyte 35 and oxygen in the air supplied to the cathode electrode 14. It is a device that uses chemical energy as electrical energy. Since the chemical reaction between hydrogen and oxygen performed at the cathode electrode 14 generates heat, the heat generation tends to deteriorate the cathode electrode 14 due to the heat generation. Since the air supplied to the cathode electrode 14 is humidified by the stacked heat exchanger 23c, the humidified air has an advantage of suppressing deterioration of the cathode electrode 14 and improving its durability reliability.

Note that the hot water flowing through the bent flow path (for hot water of high-temperature fluid) 30 of the stacked heat exchanger 23c is generated when the electrochemical element 16 including the cathode electrode 14, the hydrogen ion conductive solid electrolyte 35, and the anode electrode 15 generates power. This heat is stored in the heating body 17 which is a tank storing water.
In the heating element 17, the electrochemical element 16 is disposed by the partitioning means 18 in either the cathode 19 on the cathode electrode 14 side or the anode side space 20 on the anode electrode 15 side. Heat reception from the chemical element 16 and heating were made possible. And the heating body 17 which is a thermal storage layer, and the bending flow path (for hot water of high temperature fluid) 30 were connected, and it was set as the structure which warm water circulates with a pump (not shown).

  The solid oxide fuel cell of the present invention can be applied to uses such as a fuel cell system and an oxygen concentrator using a hydrogen ion conductive solid electrolyte.

Sectional drawing of the solid electrolyte type electrochemical apparatus of Embodiment 1-4 of this invention The disassembled perspective view of the heat exchanger used for the solid electrolyte type electrochemical apparatus of Embodiment 5 of this invention The exploded perspective view of the heat exchanger used for the solid electrolyte type electrochemical apparatus of Embodiment 6 and 7 of this invention Sectional drawing of the solid electrolyte type electrochemical apparatus of Embodiment 9 of this invention and the heat exchanger used for this shown in Embodiment 8 Exploded perspective view of a conventional solid electrolyte electrochemical device

13 Ion Conductive Solid Electrolyte 14 Cathode Electrode 15 Anode Electrode 16 Electrochemical Element 17 Heating Element 18 Partitioning Means 19 Cathode Side Space 20 Anode Side Space 21 Heat Insulating Materials 23, 23a, 23b, 23c, Heat Exchangers 24, 24a, 24b, 24c, 24d, 24e Fluid passage gap (for incoming air)
24i Fluid passage gap (for incoming air)
25, 25a, 25b, 25c, 25d, 25e Fluid passage gap (for high temperature fluid)
25j Fluid passage gap (for high temperature fluid)
26, 26a, 26b, 26c, 26d, 26e Heat exchange plate 26h, 26i, 26j, 26k, 26l, 26m, 26n Heat exchange plate 27, 27x Inlet part (for inflowing air)
27y inlet (for high temperature fluid)
28x outlet (for inflow air)
28, 28y Outlet (for high temperature fluid)
29, 29x Bent channel (for incoming air)
30, 30x bent channel (for high temperature fluid)
31 Housing 32 Internal space 33o, 33p, 33q, 33r Moisture permeable film 35 Hydrogen ion conductive solid electrolyte

Claims (1)

An electrochemical device having a cathode electrode and an anode electrode formed on both surfaces of an ion conductive solid electrolyte;
A cathode-side space in which the inflowing air in contact with the electrochemical element stays, and an anode-side space in which an anode electrode in which oxygen contained in the inflowing air reaches as oxygen ions via the ion conductive solid electrolyte is disposed Partitioning means for partitioning,
An electric heater for heating the electrochemical element;
A heat exchanger that heats the inflow air using exhaust gas discharged from the cathode side space, and supplies the heated inflow air to the cathode side space;
The heat exchanger includes a substantially flat first heat exchange plate that forms a first flow path through which the inflow air passes, and a substantially flat second heat that forms a second flow path through which the exhaust gas passes. An exchange plate and a substantially flat plate-like third heat exchange plate, and the first flow path and the second flow path are arranged so that heat exchange is performed in the lamination direction;
The electric heater is disposed in a cathode space between the heat exchanger and the electrochemical element, and is disposed so as to face a cathode electrode of the electrochemical element and a heat exchange plate of the heat exchanger. ,
Solid electrolyte fuel cell.