JP6742782B2 - Solid oxide fuel cell device - Google Patents

Description

The present invention relates to a solid oxide fuel cell device, and more particularly to a solid oxide fuel cell including a plurality of fuel battery cells that generate electricity using a fuel gas and an oxidant gas.

A solid oxide fuel cell device (Solid Oxide Fuel Cell: hereinafter also referred to as "SOFC") uses an oxide ion conductive solid electrolyte as an electrolyte, and has electrodes on both sides of the solid electrolyte to supply fuel gas on one side. A fuel cell that operates at a relatively high temperature by supplying an oxidant gas (air, oxygen, etc.) to the other side.

In the solid oxide fuel cell device, off-gas from the fuel cell is burned in the combustion section to generate high-temperature exhaust gas, steam is generated in the evaporator by heat exchange with the exhaust gas, and steam and raw material gas are mixed in the mixer. Are mixed and the raw material gas is reformed by steam in the reformer to generate a fuel gas. Conventionally, for example, as described in Patent Document 1, an evaporator and a reformer are integrally configured and arranged in a module container.

However, the evaporator absorbs heat in order to vaporize the water, which causes the temperature inside the module container to drop. On the other hand, for example, Patent Document 2 discloses a fuel cell device in which an evaporator and a mixer are arranged outside a module container, and the module container and the evaporation chamber are surrounded by a heat insulating material. As a result, the thermal efficiency in the module container is increased and the module container can be downsized.

JP, 2013-73899, A JP2012-221659A

When the evaporation chamber and the mixing chamber are provided outside the module container, it is space-saving to configure the evaporation chamber and the mixing chamber by joining them. Further, the evaporator is configured to be thin in order to effectively use the heat quantity of the exhaust gas, and has a structure in which the exhaust gas supply pipe extending from the module container is connected to one end to allow the exhaust gas to flow to the other end. Further, the joined evaporation chamber and mixing chamber are supported by the connected exhaust gas supply pipe.

In order to configure the evaporation chamber and the mixing chamber in this manner, the evaporation chamber and the mixing chamber, which are separate members, are joined together, or a partition wall is joined to the inner wall of the evaporator, and the evaporation chamber and the mixing chamber are joined together. It can be separated into and. However, since the evaporator is thin and locally supported by the exhaust gas supply pipe, stress due to its own weight acts on the entire evaporator, and the evaporation chamber and the mixing chamber, which are separate members, are joined together. Even if the partition wall is joined to the inner wall of the evaporator, a long-term load is applied to the joint portion, which causes deterioration and damage.

The present invention has been made in view of the above problems, and an object thereof is to provide a solid oxide fuel cell device in which deterioration or damage due to its own weight does not easily occur even when used for a long period of time.

The present invention is a solid oxide fuel cell device including a fuel battery cell that generates electric power from a fuel gas and an oxidant gas, including a module container and a heat insulating material provided so as to cover the periphery of the module container. , Above the fuel cell, the combustion section that burns off-gas from the fuel cell to generate exhaust gas, and above the combustion section in the module container, is heated by the exhaust gas to reform the raw material gas with steam. An evaporation chamber that generates steam from the supplied water by heat exchange between the reformer that generates fuel gas and the exhaust gas discharged from the module container, and a mixing chamber that mixes the generated steam and the supplied source gas And an evaporator having a partition wall separating the evaporation chamber and the mixing chamber, the evaporator being arranged outside the module container and inside the heat insulating material, and the bottom and side surfaces of the evaporation chamber and the bottom surface of the mixing chamber. and a side surface, and the partition wall, integrally molded member der one continuous made of the same metal member is, the evaporator further has an exhaust chamber which exhaust gas is supplied to the lower part of the evaporation chamber, the partition wall is a metal member Is formed so as to project upward so as to form a space inside, and is configured so that the exhaust gas supplied to the exhaust chamber can enter the space .

According to the present invention having the above-mentioned configuration, since the bottom surface and the side surface of the evaporation chamber, the bottom surface and the side surface of the mixing chamber, and the partition wall are composed of a continuous integrally formed member made of the same metal member, The rigidity is increased and damage due to its own weight can be prevented. Further, by constituting the integrally formed member made of the same metal member in this way, the evaporation chamber and the mixing chamber can be formed from a single metal plate by press working, the number of members is reduced, and the work process is reduced. Can be reduced.

Moreover, when the partition wall is configured as a separate member, a gap may be formed between the partition wall and the inner wall of the evaporator. Then, when water enters the gap, bumping occurs, the internal pressure of the evaporation chamber instantaneously increases due to the bumping, and fuel exhaustion occurs in which fuel gas is not supplied to the evaporation chamber. However, according to the present invention having the above-mentioned configuration, such a gap does not occur, and the occurrence of bumping due to water entering the gap can be prevented.

According to the present invention having the above-described configuration, since the partition wall located between the evaporation chamber and the mixing chamber is formed so as to project upward so that a space is formed inside, the rigidity of the evaporator is further increased by forming the space. Can be increased. Further, since the exhaust gas enters the space inside the partition wall, the partition surface is also heated to a high temperature, and the partition surface can also function as the evaporation surface of the evaporation chamber. Therefore, even when the water level in the evaporation chamber rises or when the evaporator is installed so as to be inclined, the water can be evaporated in the partition walls.

In the present invention, preferably, the evaporation chamber is filled with a granular heat conducting member.
According to the present invention having the above-described structure, since the evaporator according to the present invention can sufficiently secure the strength, it is possible to suppress the deterioration of durability due to the filling of the heat conducting member having a predetermined mass. .. The filled heat-conducting member transfers the heat received from the partition wall to the water moving between the evaporating surfaces and the heat-conducting members, so that the water can be evaporated in the evaporation chamber more efficiently.

In the present invention, preferably, a recess is formed in a part of the upper part of the partition wall, and the other part is formed as a flat upper surface, and the upper surface of the partition wall is joined with a top member covering the upper part of the evaporator, A communication passage that connects the evaporation chamber and the mixing chamber is formed between the face member and the recess.

According to the present invention having the above structure, the strength of the evaporator can be further improved by joining the upper surface of the partition wall located between the evaporation chamber and the mixing chamber to the top member. Further, since the portion other than the concave portion of the partition wall is formed flat, the upper surface of the partition wall and the top surface member can be joined without a gap, and bumping due to water droplets entering the gap can be prevented. Further, since the communication passage is formed by the recess formed in the upper portion of the partition wall, the vapor and the raw material gas are mixed in the communication passage in which the gas in the evaporation chamber has a large pressure loss, and the mixing efficiency in the evaporator is improved. You can

In the present invention, preferably, the communication passage is provided at the center in the extending direction of the partition wall.
According to the present invention having the above-described configuration, the vaporized and rising water vapor can be efficiently mixed with the raw material gas diffused in the evaporation chamber.

In the present invention, preferably, the width of the communication passage on the mixing chamber side is narrower than the width on the evaporation chamber side.
According to the present invention having the above-described configuration, the width of the communication passage narrows toward the mixing chamber, so that the mixing efficiency of the steam and the raw material gas in the communication passage can be further improved.

In the present invention, preferably, the depth of the recess from the flat upper surface is smaller than the diameter of the granular heat conducting member.
According to the present invention having the above configuration, it is possible to prevent the heat conducting member from moving to the mixing chamber via the communication passage.

According to the present invention, there is provided a solid oxide fuel cell device which is unlikely to be deteriorated or damaged by its own weight even when used for a long period of time.

1 is an overall configuration diagram showing a solid oxide fuel cell device (SOFC) according to an embodiment of the present invention. FIG. 3 is a side sectional view showing a fuel cell module of a solid oxide fuel cell device according to an embodiment of the present invention. FIG. 3 is a sectional view taken along line III-III in FIG. 2. It is an exploded perspective view of a module case and an air passage cover. It is an expanded sectional view of the evaporator of the solid oxide fuel cell device shown in FIG. FIG. 3 is a perspective view of the solid oxide fuel cell device shown in FIG. 2, in which a top plate and a combustion catalyst of the evaporator are omitted. FIG. 4 is an enlarged view showing a part of a continuous groove formed in the bottom surface of the first container of the solid oxide fuel cell according to the embodiment of the present invention. (A) is a perspective view showing plate fins provided in the exhaust gas flow path, and (B) is an enlarged view showing the vicinity of the plate fins in the evaporator. FIG. 3 is an axial cross-sectional view of a combustion catalyst device of a solid oxide fuel cell according to an embodiment of the present invention. FIG. 1 is a diagram showing a structure of a combustion catalyst of a solid oxide fuel cell according to an embodiment of the present invention. FIG. 3 is a partial cross-sectional view showing a fuel cell unit of a solid oxide fuel cell according to an embodiment of the present invention. 1 is a perspective view showing a fuel cell stack of a solid oxide fuel cell according to an embodiment of the present invention. FIG. 3 is a side sectional view similar to FIG. 2, showing a fuel cell module of a solid oxide fuel cell device according to an embodiment of the present invention. FIG. 4 is a sectional view similar to FIG. 3, taken along line III-III in FIG. 2. FIG. 3 is a perspective view showing flows of water vapor and raw fuel gas in an evaporation chamber and a mixing chamber of a solid oxide fuel cell device according to an embodiment of the present invention. FIG. 4 is an enlarged cross-sectional view showing the vicinity of a first overlapping portion and a second overlapping portion of the solid oxide fuel cell device according to the embodiment of the present invention. It is a figure which shows the continuous groove|channel formed in the bottom face of the evaporation chamber by another embodiment.

Next, a solid oxide fuel cell device according to an embodiment of the present invention will be described with reference to the accompanying drawings.
FIG. 1 is an overall configuration diagram showing a solid oxide fuel cell device (SOFC) according to an embodiment of the present invention.
As shown in FIG. 1, a solid oxide fuel cell device (SOFC) 1 according to an embodiment of the present invention includes a fuel cell module 2 and an accessory unit 4.

The fuel cell module 2 includes a housing 6, and inside the housing 6, a metallic module container 8 (hereinafter appropriately referred to as a “module case”) is built in via a heat insulating material 7. In the power generation chamber 10, which is a lower portion of the module case 8 that is the closed space, a fuel cell that performs a power generation reaction with a fuel gas and an oxidant gas (hereinafter appropriately referred to as "power generating air" or "air"). The cell aggregate 12 is arranged. This fuel battery cell assembly 12 includes eight fuel battery cell stacks 14 (details will be described later with reference to FIG. 11), and each of the fuel battery cell stacks 14 includes 16 fuel battery cells. The cell unit 16 (details will be described later with reference to FIG. 12) is configured. In this example, the fuel battery cell assembly 12 has 128 fuel battery cell units 16. The housing 6 is not essential, and a frame that holds the heat insulating material 7 may be used. In the fuel cell assembly 12, all of the plurality of fuel cell units 16 are connected in series.

A combustion chamber 18 as a combustion unit is formed above the power generation chamber 10 of the module case 8 of the fuel cell module 2, and in this combustion chamber 18, the residual fuel gas (off gas) and the residual fuel gas not used for power generation reaction The air is combusted to generate exhaust gas (in other words, combustion gas). Further, the module case 8 is covered with the heat insulating material 7 to prevent the heat inside the fuel cell module 2 from radiating to the outside air. A reformer 120 that reforms the raw fuel gas (raw material gas) is arranged above the combustion chamber 18, and the reformer 120 has a temperature at which the reforming reaction can be performed by the combustion heat of the residual gas. Is heating up.

Further, an evaporator 140 is provided in the heat insulating material 7 above the module case 8 in the housing 6. The evaporator 140 evaporates water to generate water vapor by exchanging heat between the supplied water and exhaust gas, and a mixed gas of the water vapor and the raw fuel gas (hereinafter referred to as “fuel gas”). Is also referred to as “.” is supplied to the reformer 120 in the module case 8.

Next, the auxiliary device unit 4 adjusts the flow rate of water supplied from the pure water tank 26 that stores the water that has condensed the water contained in the exhaust gas from the fuel cell module 2 and uses it as pure water by the filter. A water flow rate adjusting unit 28 (such as a “water pump” driven by a motor) is provided. In addition, the accessory unit 4 adjusts the flow rate of the fuel gas, a gas shutoff valve 32 that shuts off the fuel supplied from the fuel supply source 30 such as city gas, a desulfurizer 36 that removes sulfur from the fuel gas. A fuel flow rate adjusting unit 38 (a "fuel pump" driven by a motor, etc.) and a valve 39 for shutting off the fuel gas flowing out of the fuel flow rate adjusting unit 38 when the power source is lost. Further, the accessory unit 4 includes a solenoid valve 42 that shuts off the air supplied from the air supply source 40, a reforming air flow rate adjusting unit 44 and a power generation air flow rate adjusting unit 45 that adjust the flow rate of the air. Driven "air blower"), a first heater 46 for heating the reforming air supplied to the reformer 120, and a second heater 48 for heating the power generating air supplied to the power generation chamber. I have it. The first heater 46 and the second heater 48 are provided in order to efficiently raise the temperature at the time of startup, but they may be omitted.
In the present embodiment, the partial oxidation reforming reaction (POX) and the steam reforming reaction (SR) start from the POX step in which only the partial oxidation reforming reaction (POX) occurs in the reformer 120 when the apparatus is started. The SR process in which only the steam reforming reaction occurs may be performed through the ATR process in which the mixed auto-thermal reforming reaction (ATR) occurs, or the POX process can be omitted to change from the ATR process to the SR process. It may be configured to be transferred, or the POX process and the ATR process may be omitted and only the SR process may be performed. It should be noted that the reforming air flow rate adjusting unit 44 is not necessary in the configuration in which only the SR process is performed.

Next, to the fuel cell module 2, a hot water producing device 50 to which exhaust gas is supplied is connected. Tap water is supplied from the water supply source 24 to the hot water producing apparatus 50, and the tap water becomes hot water due to the heat of the exhaust gas and is supplied to a hot water storage tank of an external water heater (not shown). Further, the fuel cell module 2 is provided with a control box 52 for controlling the supply amount of fuel gas and the like. Further, the fuel cell module 2 is connected to an inverter 54 which is an electric power extraction unit (electric power conversion unit) for supplying the electric power generated by the fuel cell module to the outside.

Next, the structure of the fuel cell module of the solid oxide fuel cell device according to one embodiment of the present invention will be described with reference to FIGS.
2 is a side sectional view showing a fuel cell module of a solid oxide fuel cell device according to an embodiment of the present invention, and FIG. 3 is a sectional view taken along line III-III of FIG. 4 is an exploded perspective view of the module case and the air passage cover. The housing is omitted in FIGS.

As shown in FIGS. 2 and 3, the fuel cell module 2 has a fuel cell assembly 12 and a reformer 120 provided inside a module case 8 covered with a heat insulating material 7, and also has a module case 8 And an evaporator 140 provided outside and inside the heat insulating material 7.

First, as shown in FIG. 4, the module case 8 is composed of a substantially rectangular top plate 8a, a bottom plate 8c, and a pair of side plates 8b facing each other that connect the sides extending in the longitudinal direction (the left-right direction in FIG. 2). A closed side plate that closes two opposing openings at both ends of the tubular body in the longitudinal direction of the tubular body and connects the sides of the top plate 8a and the bottom plate 8c extending in the width direction (left-right direction in FIG. 3). It consists of 8d and 8e.

In the module case 8, the top plate 8a and the side plates 8b are covered by the air passage cover 160. The air passage cover 160 has a top plate 160a and a pair of side plates 160b facing each other. An opening 167 for allowing the exhaust pipe 171 to pass therethrough is provided in a substantially central portion of the top plate 160a. Further, an opening 168 to which the power generation air introduction pipe 74 is connected is provided in a portion of the top plate 160a on the closed side plate 8d side. The top plate 160a and the top plate 8a are separated from each other and the side plate 160b and the side plate 8b are separated from each other by a predetermined distance. As a result, oxidation occurs between the outside of the module case 8 and the heat insulating material 7, specifically between the top plate 8a and the side plate 8b of the module case 8 and the top plate 160a and the side plate 160b of the air passage cover 160. Air passages 161a and 161b are formed as agent gas supply passages (see FIG. 3).

The lower portion of the side plate 8b of the module case 8 is provided with air outlets 8f which are a plurality of through holes (see FIG. 4). The power generation air is supplied into the air passage 161a from the power generation air introduction pipe 74 provided in the top plate 160a of the air passage cover 160 at a substantially central portion on the side of the closing side plate 8d of the module case 8 (FIG. 2). reference). Then, the power generation air is injected into the power generation chamber 10 from the outlet 8f toward the fuel cell assembly 12 through the air passages 161a and 161b (see FIGS. 3 and 4).

Further, plate fins 162 and 163 as heat exchange promoting members are provided inside the air passages 161a and 161b (see FIG. 3). The plate fins 162 are provided in the horizontal direction so as to extend in the longitudinal direction and the width direction between the top plate 8a of the module case 8 and the top plate 160a of the air passage cover 160, and the plate fins 163 are the side plates 8b of the module case 8. And a side plate 160b of the air passage cover 160 and above the fuel cell unit 16 so as to extend in the longitudinal direction and the vertical direction.

The power generation air flowing through the air passages 161a and 161b, especially when passing through the plate fins 162 and 163, is inside the module case 8 inside the plate fins 162 and 163 (specifically, along the top plate 8a and the side plate 8b). The heat is exchanged with the exhaust gas passing through the exhaust passage (provided) and heated. For this reason, the portions of the air passages 161a and 161b where the plate fins 162 and 163 are provided function as a heat exchanger (heat exchange section). The portion provided with the plate fin 162 constitutes the main heat exchanger portion, and the portion provided with the plate fin 163 constitutes the subordinate heat exchanger portion.

Next, the evaporator 140 is fixed on the top plate 8a of the module case 8 so as to extend in the horizontal direction. The evaporator 140 is connected to the exhaust pipe 171 and the mixed gas supply pipe 112 at one end in the longitudinal direction (the left-right direction in FIG. 2), and the exhaust gas exhaust pipe 82 at the other end in the longitudinal direction. Are connected and are supported by the exhaust pipe 171. A part of the heat insulating material 7 is arranged between the evaporator 140 and the module case 8 so as to fill these gaps (see FIGS. 2 and 3).

Specifically, the evaporator 140 includes a water supply pipe 62 for supplying water and raw fuel gas (which may include reforming air) to one end of the longitudinal direction (the left-right direction in FIG. 2). The raw material supply pipe 63 and the exhaust gas exhaust pipe 82 (see FIG. 2) for exhausting exhaust gas are connected, and the upper end of the exhaust pipe 171 is connected to the other side end in the longitudinal direction. The exhaust pipe 171 extends downward through an opening 167 formed in the top plate 160a of the air passage cover 160, and is connected to an exhaust port 111 formed on the top plate 8a of the module case 8. The exhaust port 111 is an opening through which the exhaust gas generated in the combustion chamber 18 in the module case 8 is discharged to the outside of the module case 8, and is located in the central portion of the top plate 8a of the module case 8 which is substantially rectangular in a top view. Has been formed.

FIG. 5 is an enlarged sectional view of an evaporator of the solid oxide fuel cell device shown in FIG. FIG. 6 is a perspective view of the solid oxide fuel cell device shown in FIG. 2 with the top plate and the combustion catalyst of the evaporator omitted. In addition, in FIG. 6, the flow of water (water vapor) and the flow of fuel (raw material gas) are shown with a solid line and a dashed-dotted line, respectively.
The evaporator 140 has a box-shaped evaporator case 141 (FIGS. 2 and 3) that is substantially rectangular in a top view. The evaporator case 141 is composed of a first container 143, a second container 144 stacked below the first container 143, and a top plate 142 that closes the upper part of the first container 143. There is.

The top plate 142 is made of a flat metal member. An opening for connecting the raw material supply pipe 63 is formed in the widthwise center of one end of the top plate 142, and a water supply pipe 62 is connected to one side in the widthwise direction of the one end. An opening is formed.

As shown in FIGS. 5 and 6, the first container 143 includes a bottom surface 143A1 and 143A2, a side wall 143B extending upward from the outer peripheral edge of the bottom surface 143A1 and 143A2, and a flange extending horizontally outward from the upper end of the side wall 143B. The portion 143C and the partition 147 are provided.

The bottom surfaces 143A1 and 143A2 of the first container 143 are divided by the partition wall 147 into a first bottom surface 143A1 on the water supply pipe 62 and raw material supply pipe 63 side and a second bottom surface 143A2 on the mixed gas supply pipe 112 side. There is. The first bottom surface 143A1 is the bottom surface of the evaporation chamber 150 as described later, and functions as an evaporation surface for exchanging heat between the exhaust gas and the water supplied from the water supply pipe 62. The upper surface of the bottom surface 143A1 of the first container 143 is formed as a rough surface having a surface roughness Ra of 1.5 μm or more. As a result, the bottom surface 143A1 of the first container 143 has high hydrophilicity, and the water supplied onto the bottom surface 143A1 spreads over a wide range. Further, a continuous groove 156 as a water diffusion means is formed on the upper surface of the bottom surface 143A1 of the first container 143.

FIG. 7: is a figure which expands and shows a part of continuous groove formed in the bottom face of a 1st container. The lower side in FIG. 7 is the water supply pipe 62 side. As shown in the figure, on the first bottom surface 143A1 of the first container 143, square-shaped protrusions 156C are provided at equal intervals in the front-rear direction. Further, a cross-shaped protrusion 156D is formed at the center of the four square-shaped protrusions 156C that are adjacent to each other in the front, rear, left and right directions. Accordingly, the continuous groove 156 has a configuration in which the square grooves 156A are arranged at equal intervals in the front, rear, left, and right, and the central portions of the opposing sides of the adjacent square grooves 156A are connected by the connecting groove 156B. Has become.

With such a configuration, for example, water that has entered the continuous groove 156 from below in the center of FIG. 7 is bent and split left and right at the portion A, and goes straight in the groove between the portion A and the portion B. Bends at. Then, the water bent in the B section goes straight in the groove between the B section and the C section, and is further bent and divided in the C section. In this way, the water supplied to the continuous groove 156 bends and splits in the A section, goes straight in the groove between the A section and the B section, bends in the B section, and between the B section and the C section. By flowing straight in the groove and bending and branching at the C portion, the flow spreads over a wide area.

An opening is formed in the center of the second bottom surface 143A2 as an outlet of the mixing chamber 151, and the upper end of the mixed gas supply pipe 112 is connected to this opening. The mixed gas supply pipe 112 is arranged so as to pass through the inside of the exhaust pipe 171, one end of which is connected to the opening formed in the first container 143, and the other end of which is the top surface of the reformer 120. It is connected to the mixed gas supply port 120a formed in. The mixed gas supply pipe 112 passes through the exhaust pipe 171 and extends vertically downward into the module case 8, where it is bent by approximately 90° and extends horizontally along the top plate 8a, and then by approximately 90° downward. It is bent and connected to the reformer 120.

The partition wall 147 extends in the lateral direction between the side walls 143B extending in the longitudinal direction of the first container 143, and is formed by the metal material protruding upward. The partition wall 147 includes a pair of side walls 147B extending in parallel upward from the edges of the first and second bottom surfaces 143A1 and 143A2, and an upper surface 147C connecting between upper ends of the pair of side walls 147B. A recess 147A is formed in the center of the upper part of the partition 147 in the lateral direction (direction in which the partition 147 extends).

As shown in FIGS. 5 and 6, the upper surface 147C of the partition wall 147 is formed as a flat surface and is flush with the collar portion 143C. Further, the width of the recess 147A is wider on the first bottom surface 143A1 side than on the second bottom surface 143A2 side, and gradually narrows toward the second bottom surface 143A2 side. The depth of the recess 147A from the upper surface 147C is smaller than the diameter of the alumina ball filled in the evaporation chamber 150 described later. A space 147D is formed inside the partition wall 147 by being surrounded by the pair of side walls 147B and the upper surface 147C, and the space 147D is opened downward.

The first container 143 is configured by press-molding a single metal member, and the bottom surfaces 143A1 and 143A2, the side wall 143B, the collar portion 143C, and the partition wall 147 are configured as a single continuous molding member. There is.

The first container 143 and the top plate 142 are joined in a state where the lower surface of the top plate 142, the upper surface of the flange 143C and the upper surface 147C of the partition wall 147 are in contact with each other. The evaporation chamber 150 is defined by the top plate 142, the first bottom surface 143A1 of the first container 143, the side wall 143B, and the partition wall 147. In addition, the mixing chamber 151 is partitioned by the top plate 142, the second bottom surface 143A2 of the first container 143, the side wall 143B, and the partition wall 147. The evaporation chamber 150 and the mixing chamber 151 communicate with each other through a communication passage that is defined by the recess 147A of the partition wall 147 and the top plate 142, and that is located above the center of the evaporator 140 in the width direction.

The evaporation chamber 150 is filled with a plurality of granular heat conductive members. As the heat conductive member, for example, spherical alumina balls or the like can be used. The alumina balls filled in the evaporation chamber 150 are in contact with the top plate 142.

A partition member 152 is arranged in the mixing chamber 151. The partition member 152 is a member formed of a heat-resistant metal material having the same cross section and extending in the width direction. The partition member 152 includes an upper surface 152A, a pair of side wall portions 152B extending in parallel downward from both sides of the upper surface 152A, and a pair of base portions 152C extending outward from the edges of the pair of side wall portions 152B. Horizontally long openings 152D are formed on both sides in the width direction of the side wall 152B on the side of the evaporation chamber 150.

The longitudinal length of the partition member 152 is substantially equal to the width of the mixing chamber 151. The partition member 152 is arranged in the evaporation chamber 150 so as to cover the opening (exhaust port) to which the mixed gas supply pipe 112 formed in the second bottom surface 143A2 of the first container 143 is connected. In the partition member 152, the base 152C and the second bottom surface 143A2 are spot-welded while the lower surface of the base 152C is in contact with the second bottom surface 143A2 of the first container 143, whereby the first container 143 is formed. It is fixed to. The side portions of the pair of side wall portions 152B of the partition member 152 and the inner wall of the first container 143 are not welded and a gap is formed. Further, the upper surface 152A of the partition member 152 has substantially the same height as the flange portion 143C of the first container 143.

By providing the partition member 152, the space in the evaporation chamber 150 is a first space 153A between the partition wall 147 and the partition member 152 and a second space between the pair of side wall portions 152B of the partition member 152. 153B and a third space 153C between the partition member 152 and the side wall 143B of the first container 143. The first space 153A and the second space 153B communicate with each other through an opening 152D formed in the side wall 152B. In addition, the third space 153C is connected to the first space 153A and the second space 153B via a gap between both side portions of the pair of side wall portions 152B of the partition member 152 and the inner wall of the first container 143. It is in communication. Since the area of this gap is much smaller than the area of the opening 152D formed in the side wall portion 152B, the pressure loss from the first space 153A to the third space 153C is from the first space 153A to the second space 153C. Is higher than the pressure loss up to the space 153B (particularly up to the opening formed in the bottom surface of the second bottom surface 143A2). As will be described later, the second space 153B functions as a mixing flow path that mixes the water vapor and the raw material gas, and the third space 153C functions as a bumping buffer space.

The second container 144 includes a bottom surface 144A, a side wall 144B extending upward from an outer peripheral edge of the bottom surface 144A, and a flange portion 144C extending horizontally outward from an upper end of the side wall 144B. On the bottom surface 144A of the second container 144, an opening to which the upper end of the exhaust pipe 171 is connected and an opening to which the exhaust gas exhaust pipe 82 is connected are formed.

The second container 144 is superposed on the first container 143 from below. In the overlapped state, the upper surface of the flange portion 144C of the second container 144 is in contact with the lower surface of the flange portion 143C of the first container 143. The upper portion of the side wall 144B of the second container 144 is in contact with the side wall 143B of the first container 143.

Between the bottom surfaces 143A1 and 143A2 of the first container 143 and the bottom surface 144A of the second container 144, an exhaust gas passage 154 extending from the exhaust pipe 171 to the exhaust gas exhaust pipe 82 in the longitudinal direction of the evaporator 140 is provided. Has been formed. The exhaust gas flow path 154 communicates with the space 147D in the partition wall 147.

Further, plate fins 155 as heat exchange promoting members are provided in the exhaust gas passage 154. FIG. 8(A) is a perspective view showing the plate fins provided in the exhaust gas flow path, and FIG. 8(B) is an enlarged view showing the vicinity of the plate fins in the evaporator.

The plate fin 155 is manufactured by processing a single metal plate. The plate fin 155 has a plate-shaped main body 155A, a first protrusion 155B protruding downward, and a second protrusion 155C protruding upward.

In addition, each of the first protruding portions 155B is configured by a pair of inclined portions 155B1 extending obliquely downward and a connecting portion 155B2 that connects between the lower end portions of the pair of inclined portions 155B1. Then, a first passage hole 155B3 is formed at a position of the main body portion 155A that is above the first protruding portion 155B. Further, a columnar protrusion 155B4 is formed on the lower surface of the connecting portion 155B2 of the first protrusion 155B. The area of the protrusion 155B4 is smaller than the area of the connecting portion 155B2, 155C2 of the first and second protrusions 155B, 155C.

The second projecting portions 155C are respectively configured by a pair of inclined portions 155C1 extending obliquely upward and a connecting portion 155C2 connecting between upper end portions of the pair of inclined portions 155C1. A second passage hole 155C3 is formed at a position of the main body portion 155A that is below the second protrusion 155C.

In the plate fin 155, the protrusion 155B4 of the first protrusion 155B abuts on the bottom surface 144A of the second container 144, and the connecting portion 155C2 of the second protrusion 155C abuts on the bottom surface 143A1 of the first container 143. ing. Thereby, the plate fin 155 is thermally connected to the bottom surface 143A1 of the first container 143, and the thermal resistance of the plate fin 155 to the bottom surface 144A of the second container 144 is the same as that of the bottom surface 143A1 of the first container 143. Is greater than the thermal resistance of.

By disposing the plate fins 155 in the exhaust gas flow passage 154 in this manner, the exhaust gas flow passage 154 is divided into an upper space 154A and a lower space 154B by the main body portion 155A of the plate fin 155. Then, the exhaust gas flowing through the exhaust gas passage 154 flows between the upper space 154A and the lower space 154B through the first passage hole 155B3 and the second passage hole 155C3 formed in the main body portion 155A of the plate fin 155. can do.

As shown in FIG. 5, the distance between the bottom surface 143A1, 143A2 of the first container 143 and the top plate 142 is between the bottom surface 144A of the second container 144 and the bottom surface 143A1, 143A2 of the first container 143. Is greater than the distance. As a result, the ratio of the height HA of the evaporation chamber 150 to the entire height H of the evaporator 140 is higher than the ratio of the height HB of the exhaust gas passage 154 to the entire height H of the evaporator 140. Has become.

Further, the evaporator 140 includes a heater 157. As shown in FIG. 6, the evaporator 140 is provided along the outer periphery of the three sides of the rectangular evaporator 140, and both ends thereof extend toward the evaporation chamber 150 side. As shown in FIG. 5, the heater 157 laterally contacts the first overlapping portion 158A where the side wall 143B of the first container 143 and the side wall 144B of the second container 144 overlap. Further, the heater 157 is in contact with the second overlapping portion 158B where the flange portion 143C of the first container 143, the flange portion 144C of the second container 144, and the top plate 142 overlap with each other from below. The heater 157 may be provided along the entire circumference of the evaporator 140.

As shown in FIG. 5, the water supply pipe 62 and the raw material supply pipe 63 extend horizontally from the right side of FIG. 5 and straddle the side edge of the evaporator 140 on the evaporation chamber 150 side. Then, the water supply pipe 62 and the raw material supply pipe 63 are bent downward, inserted through the openings formed in the top plate 142, and opened into the inside of the evaporation chamber 150. The water supply pipe 62 is opened in the widthwise center of the end on the evaporation chamber 150 side, and the raw material supply pipe 63 is opened on the widthwise one side of the evaporation chamber 150 at the end on the evaporation chamber 150 side. There is.

The evaporator 140 also includes a temperature sensor 69. Similarly to the water supply pipe 62 and the raw material supply pipe 63, the temperature sensor 69 also extends horizontally across the side edge of the evaporator 140 on the evaporation chamber 150 side. The temperature sensor 69 is attached so as to come into contact with the upper surface of the top plate 142. The temperature sensor 69 is arranged such that the sensor portion 69A that detects the temperature of the tip thereof is located on the downstream side of the middle of the evaporation chamber 150.

The exhaust gas discharge pipe 82 is connected to one side in the width direction of the downstream end portion of the exhaust gas passage 154. The exhaust gas exhaust pipe 82 connected to the evaporator 140 extends downward, and the lower end thereof is connected to the combustion catalyst 200. The combustion catalyst 200 is a cylindrical member extending in the lateral direction, and has a cylindrical space formed therein. The exhaust gas discharge pipe 82 is connected to one end of the combustion catalyst 200, and the exhaust gas discharge pipe 202 is connected to the other end of the combustion catalyst 200. The exhaust gas discharge pipe 202 extends horizontally in a direction away from the evaporator 140 in the horizontal direction. Like the evaporator 140, the combustion catalyst 200 is arranged inside the heat insulating material 7.

As shown in FIGS. 2 and 5, the end of the evaporator 140 on the side to which the exhaust gas exhaust pipe 82 is connected extends outward from the edge of the module case 8 in a top view. The combustion catalyst 200 is located immediately below the portion of the evaporator 140 that extends outward from the edge of the module case 8. Further, the combustion catalyst device 200 is located above the reformer 120. The exhaust gas outlet of the combustion catalyst device 200 is provided at a position higher than the reformer 120, and the exhaust gas discharge pipe 202 connected to the exhaust gas outlet has a position higher than the reformer 120 in the horizontal direction. It is extended.

FIG. 9 is an axial sectional view of the combustion catalyst device. As shown in the figure, the combustion catalyst device 200 includes a container main body 204, a combustion catalyst 206 arranged inside the container main body 204, and a pair of annular fixing members arranged before and after the combustion catalyst 206 inside the container main body 204. And 208.

The container body 204 has a cylindrical shape and extends horizontally along the downstream edge of the exhaust gas flow path 154 of the evaporator 140. Further, as shown in FIG. 2, the height of the lowermost portion of the container body 204 is higher than the height of the uppermost portion of the reformer 120.

The annular fixing member 208 has an annular shape, and the outer diameter of the annular fixing member 208 is larger than the diameter of the combustion catalyst 206. The annular fixing member 208 is fixed in a state of being fitted in the container body 204.

The combustion catalyst 206 has a columnar shape and is arranged inside the container body 204. The combustion catalyst 206 is fixed in the container body 204 by being sandwiched by a pair of annular fixing members 208 from the front and rear and the front and rear. FIG. 10 is a diagram showing the structure of the combustion catalyst. As shown in the figure, the combustion catalyst 206 is formed by winding up a sheet-shaped catalyst 210. The sheet catalyst 210 includes a pair of upper and lower surfaces 210A, and an intermediate material 210B extending in a zigzag pattern. A catalyst is applied to the surfaces of the upper and lower surfaces 210A and the intermediate material 210B. As a result, the sheet catalyst 210 has a configuration in which the triangular through holes 206A are continuously arranged between the upper and lower surfaces 210A. The combustion catalyst 206 formed by rolling up the sheet-like catalyst 210 having such a configuration has a configuration in which the through holes 206A having a triangular cross section in the longitudinal direction are continuously arranged in a spiral shape without a gap. In this specification, such a configuration in which a plurality of communication holes extend in parallel is called a honeycomb type.

In such an evaporator 140, the exhaust gas supplied from the exhaust pipe 171 flows through the exhaust gas flow path 154 and is discharged to the exhaust gas discharge pipe 82. Then, the water supplied from the water supply pipe 62 to the evaporation chamber 150 flows while spreading on the bottom surface 143A1. Then, heat exchange is performed between the exhaust gas and the water via the bottom surface 143A1, and the water is evaporated to generate water vapor. The steam generated in the evaporation chamber 150 flows into the mixing chamber 151 together with the raw material gas supplied from the raw material supply pipe 63, and the steam and the fuel gas are mixed and discharged to the mixed gas supply pipe 112.

Further, the exhaust gas discharged from the exhaust gas discharge pipe 82 is supplied to the combustion catalyst device 200. The exhaust gas supplied to the combustion catalyst device 200 passes through the internal flow path in the through hole 206A of the combustion catalyst 206, oxidizes harmful gas (unburned fuel) such as carbon monoxide, and is discharged to the exhaust gas discharge pipe 202. It

Next, as shown in FIGS. 2 and 3, the reformer 120 is arranged above the combustion chamber 18 so as to extend horizontally along the longitudinal direction of the module case 8, and the top plate 8 a of the module case 8 is arranged. Are fixed to the top plate 8a while being separated by a predetermined distance via the exhaust gas guide member 130. The reformer 120 has a substantially rectangular outer shape in a top view, but is an annular structure in which a through hole 120b is formed in the central portion, and has a housing in which an upper case 121 and a lower case 122 are joined. ing. The through hole 120b is positioned so as to overlap the exhaust port 111 formed in the top plate 8a in a top view, and preferably, the exhaust port 111 is formed at the center position of the through hole 120b.

At one end side in the longitudinal direction of the reformer 120 (close side plate 8e side of the module case 8), the mixed gas supply pipe 112 is connected to the mixed gas supply port 120a provided in the upper case 121, and the other end side ( On the closed side plate 8d side), the fuel gas supply pipe 64 is connected to the lower case 122, and the hydrodesulfurizer hydrogen extraction pipe 65 extending to the desulfurizer 36 is connected to the upper case 121. Therefore, the reformer 120 receives the mixed gas (that is, the raw fuel gas mixed with steam (which may include reforming air)) from the mixed gas supply pipe 112, and internally reforms the mixed gas, The reformed gas (that is, the fuel gas) is discharged from the fuel gas supply pipe 64 and the hydrogen desulfurizer hydrogen extraction pipe 65.

The internal space of the reformer 120 is divided into three spaces by the two partition plates 123a and 123b, so that the mixed gas receiving portion 120A that receives the mixed gas from the mixed gas supply pipe 112 into the reformer 120. And a reforming section 120B filled with a reforming catalyst (not shown) for reforming the mixed gas, and a gas discharging section 120C for discharging the gas passing through the reforming section 120B. (See Figure 2). The reforming section 120B is a space sandwiched between the partition plates 123a and 123b, and the reforming catalyst is held in this space. The mixed gas and the reformed fuel gas can be moved through a plurality of communication holes (slits) provided in the partition plates 123a and 123b. Further, as the reforming catalyst, one having nickel added to the surface of alumina spheres or one having ruthenium added to the surface of alumina spheres is appropriately used.

The mixed gas supplied from the evaporator 140 via the mixed gas supply pipe 112 is jetted into the mixed gas receiving portion 120A through the mixed gas supply port 120a. This mixed gas is expanded in the mixed gas receiving portion 120A, the ejection speed is reduced, and passes through the partition plate 123a to be supplied to the reforming portion 120B.
In the reforming unit 120B, the low-speed moving mixed gas is reformed into a fuel gas by the reforming catalyst, and this fuel gas passes through the partition plate 123b and is supplied to the gas discharge unit 120C.
In the gas discharge part 120C, the fuel gas is discharged to the fuel gas supply pipe 64 and the hydrogen desulfurizer hydrogen extraction pipe 65.

The fuel gas supply pipe 64 as a fuel gas supply passage extends downward in the module case 8 along the closing side plate 8d, is bent at about 90° in the vicinity of the bottom plate 8c, and extends in the horizontal direction. It enters into the manifold 66 formed below, and further extends horizontally in the manifold 66 to the vicinity of the closing side plate 8e on the opposite side. A plurality of fuel supply holes 64b are formed on the lower surface of the horizontal portion 64a of the fuel gas supply pipe 64, and the fuel gas is supplied into the manifold 66 from the fuel supply holes 64b. A lower support plate 68 having a through hole for supporting the fuel cell stack 14 is attached above the manifold 66, and the fuel gas in the manifold 66 is supplied into the fuel cell unit 16. It Further, an ignition device 83 for starting combustion of the fuel gas and air is provided in the combustion chamber 18.

The exhaust gas guide member 130 is arranged between the reformer 120 and the top plate 8a so as to extend horizontally along the longitudinal direction of the module case 8. The exhaust gas guide member 130 includes a lower guide plate 131 and an upper guide plate 132, which are vertically separated from each other by a predetermined distance, and connecting plates 133 and 134 to which both ends in the longitudinal direction are attached (FIG. 2). , See FIG. 3). Both ends in the width direction of the upper guide plate 132 are bent downward and are connected to the lower guide plate 131. The connecting plates 133 and 134 have upper ends connected to the top plate 8a and lower ends connected to the reformer 120, thereby fixing the exhaust gas guiding member 130 and the reformer 120 to the top plate 8a. ing.

The lower guide plate 131 is formed with a convex step portion 131a whose central portion in the width direction (left-right direction in FIG. 3) projects downward. On the other hand, similar to the lower guide plate 131, the upper guide plate 132 is formed with a recess 132a such that the center portion in the width direction is recessed downward. The convex step portion 131a and the concave portion 132a extend in the longitudinal direction in parallel in the vertical direction. The mixed gas supply pipe 112 extends horizontally in the recess 132a in the module case 8 and then bends downward near the closing side plate 8e to penetrate the upper guide plate 132 and the lower guide plate 131, It is connected to the reformer 120.

In the exhaust gas guide member 130, the upper guide plate 132, the lower guide plate 131, and the connecting plates 133 and 134 form a gas reservoir 135 that is an internal space that functions as a heat insulating layer. The gas reservoir 135 is in fluid communication with the combustion chamber 18. That is, the upper guide plate 132, the lower guide plate 131, and the connecting plates 133 and 134 are connected so as to form a predetermined gap, and are not airtightly connected. It is possible for exhaust gas to flow into the gas reservoir 135 from the combustion chamber 18 during operation, and to allow air to flow from the outside when the gas chamber 135 is stopped. Is loose.

The upper guide plate 132 is arranged with a predetermined vertical distance from the top plate 8a, and an exhaust gas extending horizontally along the longitudinal direction and the width direction between the upper guide plate 132 and the top plate 8a. A passage 172 is formed. The exhaust passage 172 is arranged in parallel with the air passage 161a with the top plate 8a of the module case 8 interposed therebetween. Inside the exhaust passage 172, plate fins 162, 163 similar to the plate fins 162, 163 in the air passages 161a, 161b are provided. 175 are arranged. The plate fins 175 are provided at substantially the same positions as the plate fins 162 in a top view, and face each other in the vertical direction with the top plate 8a interposed therebetween. In the portions of the air passage 161a and the exhaust passage 172 where the plate fins 162 and 175 are provided, efficient heat exchange is performed between the power generation air flowing in the air passage 161a and the exhaust gas flowing in the exhaust passage 172. Thus, the heat of the exhaust gas raises the temperature of the power generation air.

Further, the reformer 120 is arranged with a predetermined horizontal distance from the side plate 8b of the module case 8, and the exhaust gas is passed between the reformer 120 and the side plate 8b from the lower side to the upper side. An exhaust passage 173 is formed. The exhaust gas guide member 130 is also arranged at a predetermined horizontal distance from the side plate 8b, and the exhaust passage 173 extends to the top plate 8a including the passage between the exhaust gas guide member 130 and the side plate 8b. ing. The exhaust passage 173 communicates with the exhaust passage 172 through an exhaust gas introduction port 172a located at a corner between the top plate 8a and the side plate 8b. The exhaust gas introduction port 172a extends in the longitudinal direction inside the module case 8.

Further, the lower guide plate 131 is arranged at a predetermined vertical distance from the top surface of the upper case 121 of the reformer 120, and is disposed between the lower guide plate 131 and the upper case 121 and the reformer. The through hole 120b of 120 forms an exhaust passage 174 through which the exhaust gas passing through the through hole 120b from the lower side to the upper side passes. The exhaust passage 174 merges with the exhaust passage 173 above the reformer 120.

Next, the fuel cell unit 16 will be described with reference to FIG. 11.
FIG. 11 is a partial cross-sectional view showing a fuel cell unit of a solid oxide fuel cell according to an embodiment of the present invention.
As shown in FIG. 11, the fuel cell unit 16 includes a fuel cell 84 and inner electrode terminals 86, which are caps connected to both ends of the fuel cell 84, respectively.

The fuel cell 84 is a tubular structure extending in the vertical direction, and has a cylindrical inner electrode layer 90 that forms a fuel gas flow passage 88 therein, a cylindrical outer electrode layer 92, an inner electrode layer 90 and the outside. And an electrolyte layer 94 between the electrode layer 92 and the electrode layer 92. The inner electrode layer 90 is a fuel electrode through which the fuel gas passes and serves as a (−) pole, while the outer electrode layer 92 is an air electrode in contact with air and serves as a (+) pole.

Since the inner electrode terminals 86 attached to the upper end side and the lower end side of the fuel cell 84 have the same structure, the inner electrode terminal 86 attached to the upper end side will be specifically described here. The upper portion 90a of the inner electrode layer 90 includes an outer peripheral surface 90b exposed to the electrolyte layer 94 and the outer electrode layer 92, and an upper end surface 90c. The inner electrode terminal 86 is connected to the outer peripheral surface 90b of the inner electrode layer 90 via the conductive sealing material 96, and is further in direct contact with the upper end surface 90c of the inner electrode layer 90, so that the inner electrode layer 90 is It is electrically connected. At the center of the inner electrode terminal 86, a fuel gas passage thin tube 98 communicating with the fuel gas passage 88 of the inner electrode layer 90 is formed.

The fuel gas passage thin tube 98 is an elongated thin tube provided so as to extend in the axial direction of the fuel cell 84 from the center of the inner electrode terminal 86. Therefore, a predetermined pressure loss occurs in the flow of the fuel gas flowing from the manifold 66 (see FIG. 2) into the fuel gas flow passage 88 through the fuel gas flow passage narrow tube 98 of the lower inner electrode terminal 86. To do. Therefore, the fuel gas flow path thin tube 98 of the lower inner electrode terminal 86 acts as an inflow side flow path resistance portion, and the flow path resistance is set to a predetermined value. Further, a predetermined pressure loss is also generated in the flow of the fuel gas flowing from the fuel gas flow passage 88 to the combustion chamber 18 (see FIG. 2) through the fuel gas flow passage thin tube 98 of the upper inner electrode terminal 86. Therefore, the fuel gas passage thin tube 98 of the upper inner electrode terminal 86 acts as an outflow side passage resistance portion, and the passage resistance is set to a predetermined value.

The inner electrode layer 90 includes, for example, a mixture of Ni and zirconia doped with at least one selected from rare earth elements such as Ca, Y, and Sc, Ni, and ceria doped with at least one selected from rare earth elements. It is formed of at least one of a mixture, Ni, and a mixture of lanthanum garde doped with at least one selected from Sr, Mg, Co, Fe, and Cu.

The electrolyte layer 94 is, for example, zirconia doped with at least one selected from rare earth elements such as Y and Sc, ceria doped with at least one selected from rare earth elements, lanthanum gallate doped with at least one selected from Sr and Mg, Of at least one of

The outer electrode layer 92 includes, for example, lanthanum manganite doped with at least one selected from Sr and Ca, lanthanum ferrite doped with at least one selected from Sr, Co, Ni, and Cu, Sr, Fe, Ni, and Cu. At least one selected from the group consisting of lanthanum cobaltite, silver, and the like.

Next, the fuel cell stack 14 will be described with reference to FIG.
FIG. 12 is a perspective view showing a fuel cell stack of a solid oxide fuel cell according to an embodiment of the present invention.
As shown in FIG. 12, the fuel battery cell stack 14 includes 16 fuel battery cell units 16, and these fuel battery cell units 16 are arranged in two rows of eight fuel battery cell units 16.
Each fuel cell unit 16 is supported at its lower end by a rectangular lower support plate 68 (see FIG. 2) made of ceramic, and at the upper end, four fuel cell units 16 at both ends are formed into two substantially square pieces. It is supported by the upper support plate 100. Each of the lower support plate 68 and the upper support plate 100 has a through hole through which the inner electrode terminal 86 can pass.

Further, a current collector 102 and an external terminal 104 are attached to the fuel cell unit 16. The current collector 102 includes a fuel electrode connecting portion 102a electrically connected to the inner electrode terminal 86 attached to the inner electrode layer 90 serving as a fuel electrode, and an outer peripheral surface of the outer electrode layer 92 serving as an air electrode. It is integrally formed so as to connect to the air electrode connecting portion 102b that is electrically connected. Further, a thin film made of silver is formed as an electrode on the air electrode side over the entire outer surface of the outer electrode layer 92 (air electrode) of each fuel cell unit 16. The current collector 102 is electrically connected to the entire air electrode by the contact of the air electrode connecting portion 102b with the surface of the thin film.

Further, two external terminals 104 are connected to the air electrode of the fuel cell unit 16 located at the end of the fuel cell stack 14 (the inner side on the left side in FIG. 6). These external terminals 104 are connected to the inner electrode terminals 86 of the fuel cell units 16 at the ends of the adjacent fuel cell stacks 14, and as described above, all of the 128 fuel cell units 16 are connected in series. It is supposed to be done.

Next, the flow of gas in the fuel cell module of the solid oxide fuel cell device according to the embodiment of the present invention will be described with reference to FIGS. 13 and 14.
13 is a sectional side view showing a fuel cell module of a solid oxide fuel cell device according to an embodiment of the present invention, similar to FIG. 2, and FIG. 14 is similar to FIG. It is a sectional view taken along the line III. It should be noted that FIGS. 13 and 14 are diagrams in which arrows indicating the flow of gas are newly added to FIGS. 2 and 3, respectively. In the figure, the solid arrow indicates the flow of fuel gas, the broken arrow indicates the flow of air for power generation, and the alternate long and short dash arrow indicates the flow of exhaust gas.

As shown in FIGS. 13 and 14, water and raw fuel gas (raw material gas) flow from the water supply pipe 62 and the raw material supply pipe 63 connected to one end side of the evaporator 140 in the longitudinal direction to the upper layer of the evaporator 140. It is supplied into the evaporation chamber 150 provided. The water supplied to the evaporation chamber 150 spreads over a wide range because the upper surface of the bottom surface 143A1 of the first container 143 is formed as a rough surface. Moreover, since the continuous groove 156 is formed on the upper surface of the bottom surface 143A1 of the first container 143, the continuous groove 156 is spread over a wide range. The water thus spread over a wide range is heated by the exhaust gas flowing through the exhaust gas passage 154 provided in the lower layer of the evaporator 140 to become steam. At this time, since the evaporation chamber 150 is filled with alumina balls (heat conduction member), the heat from the exhaust gas passage 154 is transferred to the water through the alumina balls. The water vapor and the raw fuel gas supplied from the raw material supply pipe 63 flow in the evaporation chamber 150 in the downstream direction.

FIG. 15 is a perspective view showing flows of water vapor and raw fuel gas in the evaporation chamber and the mixing chamber. The water vapor and the raw fuel gas generated in the evaporation chamber 150 pass through the recess 147A formed in the center of the partition 147 and flow into the mixing chamber 151. At this time, since the width of the recess 147A is narrowed toward the mixing chamber 151, the steam and the raw fuel gas are mixed more uniformly when passing through the recess 147A. At this time, since the exhaust gas enters the space 147D inside the partition 147, the steam and the raw fuel gas are heated by the partition 147. Then, the water vapor and the raw fuel gas that have flowed into the first space 153A of the mixing chamber 151 from the recess 147A separately flow on both sides in the width direction. Here, as described above, the pressure loss from the first space 153A to the third space 153C via the partition member 152 and the inner wall of the mixing chamber 151 is caused by the first space 153A via the opening 152D. To the opening formed on the bottom surface of the second bottom surface 143A2, the water vapor and raw fuel gas flowing into the first space 153A are shown by the solid line in FIG. Thus, it flows into the second space 153B through the opening 152D of the partition member 152. The water vapor and the raw fuel gas are mixed while flowing in the first space 153A and the second space 153B in this way, and are discharged to the mixed gas supply pipe 112.

When the bumping phenomenon occurs in the evaporation chamber 150, water vapor is rapidly generated in the evaporation chamber 150 and flows into the first space 153A. When such a bumping phenomenon occurs, the atmospheric pressure in the first space 153A of the evaporation chamber 150 and the mixing chamber 151 temporarily increases. When the air pressure in the first space 153A rises in this way, the water vapor in the first space 153A passes through the gap between the side portion of the partition member 152 and the inner wall of the first container 143 to create the third space 153C. It flows into. Accordingly, even when the bumping phenomenon occurs, it is possible to suppress a rapid increase in the pressure inside the evaporation chamber 150 and the mixing chamber 151.

16 is an enlarged cross-sectional view showing the vicinity of the first overlapping portion 158A and the second overlapping portion 158B. As shown in the figure, the heater 157 is arranged so as to contact the first overlapping portion 158A and the second overlapping portion 158B of the evaporator 140. Therefore, the heat from the heater 157 is effectively supplied to the bottom surface 143A2 of the first container 143 and the second container 144 via the first overlapping portion 158A and the second overlapping portion 158B as shown by the arrow in the figure. The bottom surface 144A and the top plate 142 are heated. As a result, the steam and the raw material gas in the evaporation chamber 150 and the mixing chamber 151 are heated. Further, the exhaust gas in the exhaust gas passage 154 is also heated, and this heat is transferred to the steam and the raw material gas via the bottom surface 143A2 of the first container 143, so that the steam and the raw material gas can be heated more efficiently. You can

The mixed gas (fuel gas) discharged to the mixed gas supply pipe 112 is supplied to the reformer 120 in the module case 8 through the mixed gas supply pipe 112. Since the mixed gas supply pipe 112 passes in the vicinity of the exhaust gas flow path 154, the exhaust pipe 171, and the exhaust passage 172 in order, the mixed gas in the mixed gas supply pipe 112 is changed by the exhaust gas flowing through these passages. Further heated.

The mixed gas flows into the mixed gas receiving section 120A in the reformer 120, passes through the partition plate 123a, and then flows into the reforming section 120B. The mixed gas is reformed in the reforming unit 120B to become a fuel gas. The fuel gas thus generated passes through the partition plate 123b and flows into the gas discharge portion 120C.

Further, the fuel gas is branched from the gas discharge part 120C into a fuel gas supply pipe 64 and a hydrogen desulfurizer hydrogen extraction pipe 65. Then, the fuel gas flowing into the fuel gas supply pipe 64 is supplied into the manifold 66 from the fuel supply holes 64b provided in the horizontal portion 64a of the fuel gas supply pipe 64, and from the manifold 66 into each fuel cell unit 16. Supplied.

Further, as shown in FIGS. 13 and 14, the power generation air is supplied from the power generation air introduction pipe 74 to the air passage 161a. When the power generation air passes through the plate fins 162 and 163 in the air passages 161a and 161b, the exhaust air passes through exhaust passages 172 and 173 formed in the module case 8 below the plate fins 162 and 163. Efficient heat exchange is performed with the gas, and the gas is heated. In particular, since the plate fins 175 are provided in the exhaust passage 172 so as to correspond to the plate fins 162 of the air passage 161 a, the power generation air passes through the plate fins 162 and 175 to generate exhaust gas. Perform more efficient heat exchange. After that, the power generation air is injected into the power generation chamber 10 toward the fuel cell assembly 12 from the plurality of outlets 8f provided in the lower portion of the side plate 8b of the module case 8.

In the present embodiment, since the exhaust passage is not formed in the side portion of the fuel cell assembly 12, heat exchange between the power generation air and the exhaust gas is suppressed in this portion. Therefore, in the side portion of the fuel cell assembly 12, it is difficult for a temperature gradient in the vertical direction to occur in the power generation air in the air passage 161b.

Further, as shown in FIG. 13, the fuel gas that has not been used for power generation in the power generation chamber 10 is burned in the combustion chamber 18 to become exhaust gas (combustion gas), and rises in the module case 8. Specifically, the exhaust gas branches into an exhaust passage 173 and an exhaust passage 174, and is provided between the outer surface of the reformer 120 and the side plate 8b of the module case 8 and the through hole 120b of the reformer 120. To pass between the reformer 120 and the exhaust gas guide member 130. At this time, the exhaust gas passing through the exhaust passage 174 is divided into two in the width direction by the convex step portion 131 a arranged above the through hole 120 b of the reformer 120, and does not remain at the lower portion of the exhaust gas guide member 130. The exhaust gas is guided toward the exhaust passage 173 and quickly merges with the exhaust gas flowing through the exhaust passage 173.

After that, the exhaust gas flows into the exhaust passage 172 from the exhaust gas introduction port 172a. In the exhaust passage 172, the exhaust gas horizontally flows through the exhaust passage 172 and flows out from the exhaust port 111 formed in the center of the top plate 8a of the module case 8.

When the exhaust gas flows upward in the exhaust passage 173, heat exchange is performed between the power generation air and the exhaust gas via the plate fin 163 provided in the air passage 161b. Further, when the exhaust gas horizontally flows through the exhaust passage 172, a plate fin 175 provided in the exhaust passage 172 and a plate fin 162 provided in the air passage 161 a corresponding to the plate fin 175. Through the and, efficient heat exchange is performed between the power generation air and the exhaust gas. In this way, the heat of the exhaust gas raises the temperature of the power generation air.

Then, the exhaust gas flowing out from the exhaust port 111 passes through the exhaust pipe 171 provided outside the module case 8 and flows into the exhaust gas flow path 154 of the evaporator 140. The exhaust gas flowing into the exhaust gas flow passage 154 flows through the exhaust gas flow passage 154 toward the exhaust gas exhaust pipe 82. At this time, since the plate fins 155 are provided in the exhaust gas flow path 154, heat exchange between the exhaust gas and the water in the evaporation chamber 150 is performed more efficiently.

The exhaust gas passing through the exhaust gas flow path 154 is heated by the heater 157. The heat from the heater 157 is transferred to the combustion catalyst 200 via the evaporator 140 and the exhaust gas passage 154. Further, the exhaust gas is heated by the heater 157 in the exhaust gas flow path 154, and the heated exhaust gas flows into the combustion catalyst device 200. In this way, the heat of the heater 157 is indirectly transferred to the combustion catalyst device 200, and the combustion catalyst 206 can be heated.

Then, the exhaust gas that has passed through the exhaust gas flow path 154 is discharged to the exhaust gas discharge pipe 82 and flows into the combustion catalyst device 200. The exhaust gas flowing into the combustion catalyst device 200 passes through the through hole 206A of the combustion catalyst 206. As a result, unburned gas (toxic gas) such as carbon monoxide contained in the exhaust gas comes into contact with the catalyst and is oxidized. Then, the exhaust gas flowing through the combustion catalyst device 200 is discharged to the exhaust gas discharge pipe 202.

In the above embodiment, the case where the continuous groove 156 as shown in FIG. 7 is formed on the bottom surface 143A1 of the evaporation chamber 150 has been described, but the pattern of the continuous groove formed on the bottom surface 143A1 of the evaporation chamber 150 is not limited to this. Not limited.

FIG. 17 is a view showing a continuous groove 256 formed on the bottom surface 143A1 of the evaporation chamber 150 according to another embodiment. The lower side in FIG. 17 is the water supply pipe 62 side. As shown in the figure, in the liquid of the present embodiment, a regular hexagonal protrusion 256C is provided on the first bottom surface 143A1 of the first container 143. The protrusions 256C are arranged such that the sides of the adjacent protrusions 256C face each other in parallel, whereby regular hexagonal grooves are formed in a mesh shape between the protrusions 256C. .. With such a configuration, for example, water that has entered the groove 256 from the lower center of FIG. 17 is bent and divided left and right in the D portion, goes straight in the groove of the E portion, and is bent and divided again in the D portion. It As described above, the water supplied to the continuous groove 256 flows while spreading in a wide area by repeating the bending and division in the D portion and the straight movement in the groove in the E portion.

As described above, according to the above embodiment, the following effects can be obtained.
According to the above-described embodiment, the first container 143 is configured by press-molding a single metal member, and includes the bottom surfaces 143A1 and 143A2 of the evaporation chamber 150 and the mixing chamber 151, the side wall 143B, and the collar portion 143C. , And the partition wall 147 are configured as a series of integrally molded members. Therefore, the rigidity of the evaporator 140 is increased, and damage due to its own weight can be prevented. Further, by constituting the integrally formed member made of the same metal member in this way, the evaporation chamber 150 and the mixing chamber 151 can be formed from one metal plate by press working, the number of members is reduced, and the work can be performed. The number of steps can be reduced.

Also, if the partition wall is configured as a separate member, a gap is created between the partition wall and the inner wall of the evaporator, and when water enters this gap, bumping occurs, the internal pressure of the evaporation chamber increases instantaneously, and the fuel gas Will not be supplied to the evaporation chamber, and fuel will run out. However, according to the above-described embodiment, such a gap does not occur, and it is possible to prevent the occurrence of bumping due to the water entering the gap.

Further, in the above-described embodiment, the evaporator 140 further has an exhaust gas flow path 154 to which exhaust gas is supplied below the evaporation chamber 150, and the partition wall 147 is located above the partition member 147 so that a space 147D is formed inside the metal member. It is formed so as to project and the exhaust gas supplied to the exhaust gas passage 154 can enter the space 147D. In this way, since the partition wall 147 located between the evaporation chamber 150 and the mixing chamber 151 is formed to project upward so that a space is formed inside, the rigidity of the evaporator can be further increased by forming the space. You can Further, since the exhaust gas enters the space 147D inside the partition 147, the surface of the partition 147 is also heated to a high temperature, and the surface of the partition 147 can also function as the evaporation surface of the evaporation chamber 150. Therefore, when the water level in the evaporation chamber 140 rises or when the evaporator 140 is installed at an inclination, water can be evaporated in the partition walls.

Further, in the above embodiment, the evaporation chamber 150 is filled with a granular heat conducting member. As described above, according to the above-described embodiment, since the evaporator 140 is sufficiently secured in strength, it is possible to suppress deterioration in durability due to filling the heat conducting member having a predetermined mass. Further, since the filled heat conducting member transfers the heat received from the partition wall 147 to the water moving between the evaporation surfaces and the heat conducting members, the water can be evaporated in the evaporation chamber 150 more efficiently.

In addition, in the above-described embodiment, the recess 147A is formed in a part of the upper part of the partition 147, and the other part is formed as a flat upper surface 147C, and the upper surface 147C of the partition 147 covers the upper part of the evaporator 140. A communication passage is formed between the evaporation chamber 150 and the mixing chamber 151, which is joined to the top plate 142 and the recess 147A. By thus joining the upper surface of the partition wall 147 located between the evaporation chamber 150 and the mixing chamber 151 to the top plate 142, the strength of the evaporator 140 can be further improved. Further, since the partition wall 147 is formed to be flat except the recessed portion 147A, the upper surface 147C of the partition wall 147 and the top plate 142 can be joined without a gap, and water droplets may enter the gap to cause bumping. Can be prevented. Further, since the communication passage is formed by the recess 147A formed in the upper part of the partition wall 147, the gas in the evaporation chamber 150 is mixed with the steam and the raw material gas in the communication passage having a large pressure loss, and is mixed in the evaporator 140. The efficiency can be improved.

Further, in the above-described embodiment, the communication passage that communicates with the evaporation chamber 150 and the mixing chamber 151 is provided at the center of the partition 147 in the extending direction. As a result, the water vapor that vaporizes and rises in the evaporation chamber 150 and the source gas that diffuses in the evaporation chamber 150 can be efficiently mixed.

In addition, in the above-described embodiment, the width of the communication passage communicating with the evaporation chamber 150 and the mixing chamber 151 on the mixing chamber 151 side is narrower than the width on the evaporation chamber 150 side. In this way, the width of the communication passage narrows toward the mixing chamber 151, so that the mixing efficiency of the steam and the raw material gas in the communication passage can be further improved.

Further, in the above embodiment, the depth of the recess 147A of the partition wall 147 from the flat upper surface 147C is smaller than the diameter of the granular heat conducting member filled in the evaporation chamber 150. This can prevent the heat conducting member from moving to the mixing chamber 151 via the communication passage.

1 Solid Oxide Fuel Cell Device 2 Fuel Cell Module 4 Auxiliary Unit 6 Housing 7 Heat Insulating Material 8 Module Case 8 Closing Side Plate 8a Top Plate 8b Side Plate 8c Bottom Plate 8d Closing Side Plate 8e Closing Side Plate 8f Blowout Port 10 Power Generation Chamber 12 Fuel Cell Cell Assembly 13 Lower guide plate 14 Fuel cell stack 16 Fuel cell unit 18 Combustion chamber 24 Water supply source 26 Pure water tank 28 Water flow rate adjustment unit 30 Fuel supply source 32 Gas cutoff valve 36 Desulfurizer 38 Fuel flow rate adjustment unit 39 Valve 40 Air Supply Source 42 Solenoid Valve 44 Reforming Air Flow Rate Adjustment Unit 45 Power Generation Air Flow Rate Adjustment Unit 50 Hot Water Production Device 52 Control Box 54 Inverter 62 Water Supply Pipe 63 Raw Material Supply Pipe 64 Fuel Gas Supply Pipe 64a Horizontal Part 64b Fuel Supply Hole 65 Hydrodesulfurization pipe for hydrodesulfurizer 66 Manifold 68 Lower support plate 69 Temperature sensor 69A Sensor part 74 Air inlet pipe for power generation 82 Exhaust gas exhaust pipe 83 Ignition device 84 Fuel cell cell 86 Inner electrode terminal 88 Fuel gas flow passage 90 Inside Electrode layer 90a Upper part 90b Outer peripheral surface 90c Upper end surface 92 Outer electrode layer 94 Electrolyte layer 96 Sealing material 98 Fuel gas passage narrow tube 100 Upper support plate 102 Current collector 102a Fuel electrode connecting portion 102b Air electrode connecting portion 104 External terminal 111 Exhaust port 112 Mixed gas supply pipe 120 Reformer 120A Mixed gas receiving part 120B Reforming part 120C Gas discharge part 120a Mixed gas supply port 120b Through hole 121 Upper case 122 Lower case 123a Partition plate 123b Partition plate 130 Exhaust gas guide member 131 Lower Guide Plate 131a Convex Step 132 Upper Guide Plate 132a Recess 133 Connecting Plate 135 Gas Reservoir 140 Evaporator 141 Evaporator Case 142 Top Plate 143 First Container 143A1 Bottom 143A2 Bottom 143B Side Wall 143C Collar 144 Second Container 144A Bottom surface 144B Side wall 144C Collar portion 147 Partition wall 147A Recessed portion 147B Side wall 147C Upper surface 147D Space 150 Evaporation chamber 151 Mixing chamber 152 Partition member 152A Upper surface 152B Side wall portion 152C Base portion 152D Opening 153A First space 153B Second space 153C Third space Space 154 Exhaust gas flow path 154A Upper space 154B Lower space 155 Plate fin 155A Body part 155B Projection part 155B1 Inclined part 155B2 Connecting part 1 55B3 passing hole 155B4 protruding portion 155C protruding portion 155C1 inclined portion 155C2 connecting portion 155C3 passing hole 156 continuous groove 156A square groove 156B connecting groove 156C protruding portion 156D protruding portion 157 heater 158A first overlapping portion 158B second overlapping portion 160 Air passage cover 160a Top plate 160b Side plate 161a Air passage 161b Air passage 162 Plate fin 163 Plate fin 167 Opening 171 Exhaust pipe 172 Exhaust passage 172a Exhaust gas inlet 173 Exhaust passage 174 Exhaust passage 175 Plate fin 200 Combustion catalyst 202 Exhaust gas emission Tube 204 Container body 206 Combustion catalyst 206A Through hole 208 Annular fixing member 210 Sheet catalyst 210A Upper and lower surfaces 210B Intermediate material 256 Continuous groove 256C Projection

Claims (6)

A solid oxide fuel cell device comprising a fuel battery cell for generating power with a fuel gas and an oxidant gas,
Module container,
A heat insulating material provided so as to cover the periphery of the module container,
Above the fuel cell, a combustion unit that combusts off gas from the fuel cell to generate exhaust gas,
Above the combustion section in the module container, a reformer for heating the exhaust gas to reform the raw material gas with steam to generate the fuel gas,
An evaporation chamber that generates steam from the supplied water by heat exchange with the exhaust gas discharged from the module container, a mixing chamber that mixes the generated steam and the supplied source gas, and an evaporation chamber and the A partition wall separating the mixing chamber is provided, and an evaporator disposed outside the module container and inside the heat insulating material,
A bottom and side surfaces of the evaporation chamber, and the bottom and side surfaces of the mixing chamber, with the partition wall, Ri integrally molded member der one continuous made of the same metal member,
The evaporator further has an exhaust chamber to which the exhaust gas is supplied below the evaporation chamber,
The partition wall is formed so that the metal member projects upward so as to form a space inside, and is configured so that the exhaust gas supplied to the exhaust chamber can enter the space. A solid oxide fuel cell device characterized by: Wherein the evaporation chamber, the heat conducting member granular is filled, the solid oxide fuel cell device according to claim 1. A recess is formed in a part of the upper part of the partition wall, and the other part is formed as a flat upper surface,
An upper surface of the partition wall is joined to a top member that covers an upper portion of the evaporator,
Wherein between the top member and the recess, said an evaporation chamber, the communication passage and the mixing chamber is communicated is formed, the solid oxide fuel cell device according to claim 1. The solid oxide fuel cell device according to claim 3 , wherein the communication passage is provided at a center in the extending direction of the partition wall. The solid oxide fuel cell device according to claim 4 , wherein the width of the communication passage on the side of the mixing chamber is narrower than the width on the side of the evaporation chamber. The solid oxide fuel cell device according to claim 5 , wherein the depth of the recess from the flat upper surface is smaller than the diameter of the granular heat conducting member.

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