JP7152204B2 - fuel cell device - Google Patents

Description

The present invention relates to fuel cell devices.

A fuel cell device includes a fuel cell module and a heat exchanger for recovering thermal energy of exhaust gas discharged from the fuel cell module in a housing such as an exterior case.

The heat exchanger, for example, as described in Patent Document 1, is arranged so as to hang down from the lower side of the fuel cell module surrounded by a heat insulating material. is connected and fixed to the exhaust port of the fuel cell module.

JP 2009-32652 A Japanese Patent No. 6216901

A fuel cell device according to the present disclosure includes a cell stack in which a plurality of fuel cells are arranged along a predetermined direction, a storage container that stores the cell stack,
It is housed in a storage container and is capable of steam reforming extending along the arrangement direction of the fuel cells, and has a vaporization section located on the first end side of one end in the cell arrangement direction and a second end at the other end in the cell arrangement direction. a fuel cell module comprising a reformer having a reformer located on the two end side ;
a heat insulating material covering the entire surface of the storage container;
a first member positioned over the insulation ;
a heat storage tank that stores a heat medium;
arranged side by side on the first surface and connected to the first member,
a first heat exchanger for exchanging heat between a high-temperature exhaust gas generated in the fuel cell module and a heat medium;
a second heat exchanger that exchanges heat between the heat medium stored in the heat storage tank and the fluid introduced from the outside,
The first heat exchanger is located on the first end side from the center in the cell arrangement direction on the first surface,
The second heat exchanger is located closer to the second end than the first heat exchanger on the first surface .

1 is a schematic configuration diagram of a fuel cell device according to an embodiment; FIG. FIG. 2 is an exploded view for explaining the internal configuration of the housing of the fuel cell device; FIG. 3 is a perspective view for explaining the internal configuration of the fuel cell module;

Hereinafter, the fuel cell device of the embodiment will be described with reference to the drawings.
FIG. 1 is a schematic configuration diagram of a fuel cell device 100 according to an embodiment, and FIG. 2 is an exploded view for explaining the arrangement of each device and piping within a housing 60 of the fuel cell device 100. As shown in FIG. 3 is a perspective view for explaining the internal configuration of the fuel cell module 1 covered with the heat insulating material 13. As shown in FIG. Of the three orthogonal XYZ directions shown in the drawing, the X direction indicates the arrangement direction of the fuel cells and the cell stack 11 in the module.

A fuel cell device 100 of the embodiment shown in FIG. , a first heat exchanger 4 for exchanging heat between a high-temperature exhaust gas and a low-temperature heat medium, a heat medium circulation pump P1, a low-temperature heat medium pipe 21 as a heat medium circulation flow path, a high-temperature heat medium pipe 22, etc. It is a cogeneration system that stores or supplies hot water using an exhaust heat recovery system.

The exhaust heat recovery system described above is hereinafter referred to as primary heat cycle HS1. The primary heat cycle HS1 is a range surrounded by a dashed line indicated by symbol HS1 in FIG. Water, for example, is used as a circulating heat medium in the primary heat cycle HS1. Since high-temperature exhaust gas flows through the first heat exchanger 4, the temperature is basically higher than normal temperature (for example, 23°C).

The fuel cell device 100 uses the high-temperature hot water (also referred to as hot water or hot water) stored in the heat storage tank 2 as a heat medium, and heat exchanges with water (low-temperature or cold water) supplied from the outside such as tap water. ) and used as a heat source for hot water supply and room heating (hereinafter referred to as a secondary heat cycle HS2).

As shown in FIG. 1, the secondary heat cycle HS2 includes a heat storage tank 2 shared with the primary heat cycle HS1, and a second heat exchanger that exchanges heat between high-temperature water and low-temperature tap water as a heat medium. 6, a heat medium circulation pump P2, a high temperature water pipe 23, a low temperature water pipe 24, etc. as a heat medium circulation flow path. In FIG. 1, the secondary heat cycle HS2 is a range surrounded by a chain double-dashed line indicated by symbol HS2. High-temperature water stored in the upper high-temperature portion of the heat storage tank 2 is used as a circulating heat medium in the secondary heat cycle HS2. Since the second heat exchanger 6 exchanges heat between high-temperature water having a temperature higher than normal temperature and tap water having a temperature close to normal temperature, the temperature is basically higher than normal temperature.

Heated tap water (hereinafter referred to as heated water) generated by the second heat exchanger 6 is used for supplying hot water to a water heater as shown in FIG. 1, for example. In the present embodiment, the low-temperature fluid inlet of the second heat exchanger 6 is connected to the water supply pipe 31 connected to the water supply, and the low-temperature fluid outlet is connected to the hot water supply pipe connected to the water heater. 32 are connected. A bypass pipe 33 for adjusting the temperature of hot water is connected between the clean water pipe 31 and the hot water pipe 32 via a flow control valve.

The high-temperature fluid inlet of the second heat exchanger 6 is connected to the high-temperature water pipe 23 that constitutes the upstream side of the heat medium circulation flow path described above, and the high-temperature fluid outlet is connected to the heat medium circulation flow path. A low-temperature water pipe 24 that constitutes the downstream side is connected.

In the fuel cell device 100, an exterior case 60, which is a housing shown in FIG. Auxiliary machines and the like are arranged. FIG. 2 depicts a state in which parts of the exterior strut 61 and the exterior (decorative) panel 62 of the exterior case 60 are removed.

In FIG. 1, on the downstream side of the exhaust gas flow path in the first heat exchanger 4, an exhaust gas (exhaust) flow path 41 for discharging the exhaust gas whose temperature has been reduced by heat exchange to the outside of the apparatus, and moisture in the exhaust gas and A condensed water flow path 42 is provided for allowing condensed water generated by condensation of water vapor or the like to flow through the reforming water tank 5 . A reforming water pump P3 for supplying the reforming water stored in the reforming water tank 5 to the reformer 12 in the fuel cell module 1, and a reforming water flow path 51 are provided.

In addition, the raw fuel pump B1 and the raw fuel gas flow path 52 that supply the raw fuel such as natural gas (13A) supplied from the outside to the reformer 12, and the air outside the device is reformed as an oxygen-containing gas. An air blower B2 for supplying to the vessel 12 and an oxygen-containing gas flow path 53 are provided. A power conditioner, a control device, a storage device, and the like, which are not shown, are also arranged in the outer case 60 as auxiliary devices.

The fuel cell module 1 in the exterior case 60 is provided with a heat insulating material 13 on the entire surface of the storage container 10, that is, on the outside of the six surfaces including the upper and lower surfaces in this example, for heat retention. As shown in 3, the entire surface other than the necessary openings for inserting pipes and the like is covered with a heat-insulating member.

Reference numeral 14 in the drawing denotes a member (hereinafter referred to as a first member) for fixing the heat insulating material 13 to the outer surface of the storage container 10 . The material constituting the first member 14 may be, for example, a metal, and generally a material having a higher thermal conductivity than the heat insulating material 13 is used. Therefore, the region where the first member 14 covering the heat insulating material 13 is provided tends to release the heat of the fuel cell module 1 in particular. As shown in FIG. 2, the first member 14 disposed on each outer surface of the storage container 10 has an opening that serves as a window through which the inner heat insulating material 13 can be checked in order to suppress heat release from the fuel cell module. may be provided.

By the way, in the conventional fuel cell device, in order to suppress the release of heat inside the fuel cell module 1, the heat (thermal energy) generated by the heat exchanger could not be used.

In contrast, in the fuel cell device 100 of the embodiment, the heat exchangers 4 and 6 are connected to the first member 14 as shown in FIG. With this configuration, the heat of the heat exchangers 4 and 6 can be used to heat the first member 14, which is the outer surface of the fuel cell module 1, and thus the heat inside the fuel cell module 1 can be efficiently released. can be well suppressed.

Here, “connection” as used in the present disclosure means that the first member 14 and the heat exchangers 4 and 6 are in direct or indirect contact, and the heat of the heat exchangers 4 and 6 is transferred to the first member 14 means that it is connected in such a way that it can communicate to

In this embodiment, a fixing member 15 for fixing the first heat exchanger 4 and the second heat exchanger 6 to the first member 14 is provided. The first heat exchanger 4 and the second heat exchanger 6 are connected via a fixing member 15 to a first member 14 covering a heat insulating material 13, and the heat of the heat exchangers 4 and 6 is transferred to the first member 14. is connected so that it can communicate to

The heat exchangers 4 and 6 themselves may be covered with another heat insulating material newly provided. , the heat of the heat exchangers 4 , 6 can be transferred to the first member 14 .

The fixing member 15 may be made of the same material as the first member 14 and may be provided integrally with the first member 14 , or may be made of a material different from that of the first member 14 . Furthermore, the fixing member 15 can also be provided integrally with the first heat exchanger 4 and the second heat exchanger 6 . The first heat exchanger 4 and the second heat exchanger 6 are fixed to the first member 14 by fastening or the like via the fixing member 15 . With this configuration, there is no need to separately provide a member for fixing the heat exchangers 4 and 6, so the entire fuel cell device can be configured compactly.

Here, first, the internal configuration of the fuel cell module 1 arranged inside the exterior case 60 will be described.

FIG. 3 is an external perspective view of the fuel cell module 1, omitting illustration of the first member 14 covering the heat insulating material 13 adhered to the outside of the storage container 10 (not shown). As described above, the fuel cell module 1 used in the embodiment is a rectangular parallelepiped whose outer surface is covered with the heat insulating material 13, and its heat exchanger mounting surface (the front surface visible in FIGS. 2 and 3; hereinafter referred to as the first surface) ) is provided with two openings 10a and 10b. A cell stack 11 and a reformer 12 housed in a storage container 10 (not shown) are arranged inside the heat insulating material 13 as shown in the perspective view thereof.

Although not shown in FIG. 3, an internal heat insulating material is filled between the cell stack 11 and reformer 12 and the storage container 10, and this internal heat insulating material allows reforming of the upper side of the cell stack 11. A combustion chamber is formed around the vessel 12 to burn excess reformed gas.

In addition, between the inner box and the outer box of the storage container 10, which is a double container, there is an air flow path (the oxygen-containing gas flow path 53 in FIG. inside the container 10), and an exhaust gas flow path in the upper part of the cell stack 11 that discharges the combustion exhaust gas burned in the combustion chamber to the outside of the container 10 (the part inside the container 10 of the exhaust gas flow channel 41 in FIG. 1). and is provided.

The cell stack 11 of this embodiment shown in FIG. 3 has a structure in which a plurality of columnar fuel cells are arranged in a row in the X direction. The reformer 12 disposed in the combustion chamber (not shown) on the upper side of the cell stack 11 has a straight shape or a straight tubular shape as shown in the figure, and is similar to the cell stack 11 in the arrangement direction of the fuel cells. are arranged along the illustrated X direction.

The reformer 12 inside the fuel cell module 1 divides the reforming water into an inner pipe and an outer pipe and supplies the reforming water through a double pipe provided with a reforming water flow channel 51 and a raw fuel gas flow channel 52 in the X direction. The raw fuel is vaporized in the vaporizing section 12A located on the negative side (right side in the figure) and reformed by steam reforming using the steam in the reforming section 12B located on the positive side in the X direction (left side in the figure). produce pollutant gas.

In the reformer 12, the fluid flows in one direction from the vaporizing section 12A side to the reforming section 12B side, that is, from the upstream side to the downstream side. In the reformer 12, the end on the upstream side (the right side in the drawing, the negative side in the X direction) where the vaporization section 12A is located is the first end, and the downstream side where the reforming section 12B is positioned (the left side in the drawing, the positive side in the X direction). is called the second end.

Then, of the two openings shown in FIG. The through-hole located below is an air introduction pipe insertion port 10a for introducing external air into the oxygen-containing gas flow path 53, and is located on the negative side in the X direction and above the vaporization section 12A side (right side in the drawing). The through-hole located at is a flue gas outlet 10b through which high-temperature flue gas flows toward the first heat exchanger 4 of the primary heat cycle HS1 for exhaust heat recovery.

Here, the positions corresponding to the arrangement positions of the auxiliary devices and the flow path pipes around the fuel cell module 1 in the exterior case 60 described in FIG. chain line), the first heat exchanger 4 of the primary heat cycle HS1 and the second heat exchanger 6 of the secondary heat cycle HS2 are fixed members 15 attached to a first member 14 (not shown in FIG. 3). is attached to the first member 14 (not shown) that covers at least a portion of the heat insulating material 13 via.

Since each heat exchanger 4, 6 is attached to the first member 14 via the fixing member 15, it is not directly connected to the first member 14, but each heat exchanger 4, 6 and the storage container (not shown), the first member 14 is arranged. With this configuration, the heat of the heat exchanger can be used to heat the first member 14 more efficiently, and the release of heat inside the fuel cell module 1 can be efficiently suppressed. Needless to say, the first member 14 located between each heat exchanger 4, 6 and the container 10 and each heat exchanger 4, 6 may be directly connected.

At least one of the first heat exchanger 4 and the second heat exchanger 6, in this case the first heat exchanger 4, which tends to be hotter, is located on the side of the container (not shown) The region on the first end side from the center in the cell arrangement direction (X direction) on the first surface (the front visible in FIGS. 2 and 3) along the cell arrangement direction (X direction), that is, the vaporization section 12A side in the drawing It is arranged in the right half area. With this configuration, it is possible to suppress the heat radiation from the region of the storage container 10 on the side of the vaporizing section 12A, which has a relatively low temperature, thereby contributing to the uniformity of the temperature distribution of the entire fuel cell module.

The first heat exchanger 4 is the projection surface of the first heat exchanger 4 described above in a projection view viewed from the positive direction in the Y direction, which is the direction outside the first surface (the front visible in FIG. 3). , and the projection plane of the vaporization section 12A positioned on the first end (the right end in the drawing and on the negative side in the X direction). With this configuration, it is possible to further suppress the heat radiation from the region of the storage container 10 on the side of the vaporization section 12A, which has a relatively low temperature, thereby contributing to the uniformity of the temperature distribution of the entire fuel cell module.

When two heat exchangers are arranged on the heat exchanger mounting surface (the first surface on which the fixing member 15 is provided) as in the present embodiment, as shown in FIG. The first heat exchanger 4 of the HS 1 is arranged on the first end (vaporization section 12A) side of the center in the cell arrangement direction (X direction) on the first surface. The second heat exchanger 6 of the secondary heat cycle HS2, which tends to have a lower temperature, is arranged closer to the second end (reforming section 12B) than the first heat exchanger 4 on the first surface.

In the fuel cell device 100 shown in FIGS. 1 and 2, the fuel cell module 1 has a through hole for inserting the air introduction pipe 53 (air introduction pipe insertion port 10a in FIG. It is provided on the second end (reforming section 12B) side from the center in the direction (X direction). Since air having a temperature lower than the temperature inside the storage container 10 flows through the air introduction pipe 53, the temperature around the through hole (air introduction pipe insertion port 10a) is relatively low.

Therefore, when viewed as a whole of the fuel cell module 1 as shown in FIGS. and the air introduction pipe 53 inserted through it extends from the first end (vaporization section 12A) to the second end (reformation section 12B) in the cell arrangement direction (X direction) on the first surface as shown in the figure. They are arranged in order. These configurations can further contribute to making the temperature distribution uniform throughout the fuel cell module.

In addition, when each of the heat exchangers 4 and 6 described above is a brazed plate type heat exchanger, in order to keep the fuel cell module 1 warm, the surface of the brazed plate type heat exchanger that becomes the highest temperature is the first It may be fixed to the fixing member 15 toward the member 14 side. That is, in each of the heat exchangers 4 and 6, by bringing the outer surface facing the high-temperature flow path through which the high-temperature heat medium flows closer to the first member 14, the fuel cell module 1 can be kept warmer. .

Further, for example, the second heat exchanger 6 is of a brazing plate type, and as shown in FIG. When the hot water supply pipe 32 connected to the water heater is connected to the outlet that is the outlet of the low temperature fluid, the water supply pipe 31 with the lowest temperature is the heat exchanger mounting surface (the first surface with the fixing member 15 ) so as to be farthest from the That is, the water supply pipe 31 is routed at a position away from the fuel cell module 1 with the second heat exchanger 6 interposed therebetween. As a result, it is possible to prevent the low-temperature tap water pipe 31 from taking heat from the fuel cell module 1 .

Although the embodiments of the present disclosure have been described in detail above, the present disclosure is not limited to the above-described embodiments, and various modifications, improvements, etc. are possible without departing from the gist of the present disclosure. .

REFERENCE SIGNS LIST 1 fuel cell module 2 heat storage tank 4 first heat exchanger 6 second heat exchanger 10 storage container 10a air introduction pipe insertion port (through hole)
10b flue gas outlet 11 cell stack 12 reformer 12A vaporizer 12B reformer 13 heat insulating material 14 first member 15 fixing member 31 tap water pipe 32 hot water supply pipe 53 oxygen-containing gas flow path (air introduction pipe)
100 fuel cell device

Claims (6)

a cell stack in which a plurality of fuel cells are arranged along a predetermined direction ; a storage container that stores the cell stack;
It is housed in a storage container and is capable of steam reforming extending along the arrangement direction of the fuel cells, and has a vaporization section located on the first end side of one end in the cell arrangement direction and a second end at the other end in the cell arrangement direction. a fuel cell module comprising a reformer having a reformer located on the two end side ;
a heat insulating material covering the entire surface of the storage container;
a first member positioned over the insulation ;
a heat storage tank that stores a heat medium;
arranged side by side on the first surface and connected to the first member,
a first heat exchanger for exchanging heat between high-temperature exhaust gas generated in the fuel cell module and a heat medium;
a second heat exchanger that exchanges heat between the heat medium stored in the heat storage tank and the fluid introduced from the outside,
The first heat exchanger is located on the first end side from the center in the cell arrangement direction on the first surface,
The second heat exchanger is located closer to the second end than the first heat exchanger on the first surface
fuel cell device. 2. The fuel cell apparatus according to claim 1, wherein said first member is positioned between said heat exchanger and said container. 3. The fuel cell device according to claim 1, wherein said heat exchanger has a high-temperature channel through which a high-temperature heat medium flows, the channel closest to the surface facing said first member. In a projection view seen from the outside of the first surface,
2. The fuel cell device according to claim 1, wherein a projected plane of said heat exchanger and a projected plane of said evaporating section, which are located facing said first end region, at least partially overlap. an air introduction pipe that supplies air as an oxygen-containing gas from the outside to the fuel cell module;
a through hole for inserting an air introduction pipe provided on the first surface,
5. The fuel cell device according to any one of claims 1 to 4, wherein the through-hole is located on the second end side of the center in the cell arrangement direction on the first surface. 6. The method according to claim 5, wherein the first heat exchanger, the second heat exchanger, and the through hole are arranged in this order from the first end to the second end in the cell arrangement direction on the first surface. A fuel cell device as described.

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