JP2010238622A - Fuel cell module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel cell module capable of preventing variations of temperatures of a fuel battery cell aggregate as well as realizing compactification. <P>SOLUTION: The fuel cell module 2 is equipped with the fuel battery cell assembly 12 having a plurality of fuel battery cells 16 operated by a fuel gas and an oxygen containing gas, and has a power generating chamber 10 in which the fuel battery cell assembly is arranged, an exhaust gas discharge passage 80 in order to discharge the fuel gas unused in operation of the fuel battery cells 16, and an exhaust gas formed by burning of the oxygen containing gas from the upward space of the power generating chamber, and an air layer 84 formed in a space between this exhaust gas discharge passage and the power generating chamber. An exhaust gas flow-in preventive part 90 is formed at a part in contact with the exhaust gas discharge passage of the air layer to prevent flow-in of the exhaust gas into the air layer. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a fuel cell module, and more particularly, to a fuel cell module including a fuel cell assembly composed of a plurality of fuel cells that operate with fuel gas and oxygen-containing gas.

  A solid oxide fuel cell (hereinafter also referred to as “SOFC”) uses an oxide ion conductive solid electrolyte as an electrolyte, has electrodes attached to both sides thereof, supplies fuel gas to one side, and supplies the other. This is a fuel cell that generates electricity by supplying air to the side and generating a power generation reaction at a relatively high temperature.

  In this type of fuel cell, the fuel gas that does not contribute to power generation and the oxidant-containing gas (air) burn in the power generation chamber that houses the fuel cell assembly, and the exhaust gas is exhausted from the upper portion of the power generation chamber. It is discharged through the discharge path.

Patent Document 1 discloses a power generation chamber that accommodates a cell stack in which fuel cells are arranged in a row, and an exhaust gas that is provided on both sides of the power generation chamber and in which an oxygen-containing gas and fuel gas that are not used for power generation are burned. A fuel cell module provided with an exhaust gas circulation space for discharging gas is disclosed. In the document 1, a heat insulating material is disposed between the power generation chamber and the exhaust gas circulation space.

  Similarly, Patent Document 2 discloses a fuel cell system (fuel cell module) including a power generation chamber that houses a fuel cell stack, and a heat insulating and heat insulating layer disposed around the power generation chamber. In the thing of this patent document 2, since the reaction heat generated with the power generation reaction in the power generation chamber is radiated to the outside through this heat insulating heat insulation layer, in order to prevent this heat loss and effectively use the reaction heat, Heat utilization means such as a jacket container containing water is provided in the heat insulation layer.

JP 2008-66127 A JP 2005-1000082 A

  As described in Patent Document 1 and Patent Document 2 described above, when a heat insulating material or a heat insulation layer is provided around the power generation chamber, the center portion of the fuel cell stack becomes relatively high temperature, while the periphery of the cell stack is Since the temperature is relatively low and there is a variation in temperature, the thickness of the heat insulating material or the heat insulating heat insulating layer must be a thickness corresponding to the temperature of the center portion of the cell stack, which is a relatively high temperature. Or in the fuel cell module in which the thickness of the heat insulation and heat insulation layer becomes large and the downsizing is required, it is a problem.

  Furthermore, although not explicitly disclosed in Patent Document 1 and Patent Document 2, temperature variations in the fuel cell stack and the fuel cell assembly are not preferable in order to perform a favorable battery reaction.

  Accordingly, the present invention has been made to solve the above-described problems of the prior art, and provides a fuel cell module that can be made compact and can prevent variations in temperature of the fuel cell assembly. The purpose is that.

In order to achieve the above object, the present invention provides a fuel cell module including a fuel cell assembly having a plurality of fuel cells operated by a fuel gas and an oxygen-containing gas. A power generation chamber, an exhaust gas exhaust passage for exhausting exhaust gas generated by combustion of fuel gas and oxygen-containing gas not used in the operation of the fuel cell from the space above the power generation chamber, and the exhaust gas An exhaust layer that has an air layer formed in a space between the exhaust passage and the power generation chamber, and that prevents the exhaust gas from flowing into the air layer at a portion of the air layer that contacts the exhaust gas exhaust passage It is characterized by having formed.
In the present invention configured as described above, an air layer is formed in the space between the exhaust gas discharge path and the power generation chamber, so that the air layer has a heat insulating function, and thus the power generation chamber discharges the exhaust gas. It is insulated from the road, and the temperature drop of the power generation chamber can be prevented. Next, when heat is transferred from the power generation chamber to the air layer, the air is thermally diffused from the high temperature region to the low temperature region in the air layer, so that the temperature of the air in the air layer is made uniform. Variations in body temperature can be suppressed. Further, since the exhaust gas inflow prevention portion is provided to prevent the exhaust gas from flowing into the air layer, the exhaust gas does not flow into the air layer and local temperature variation does not occur. Further, since the air layer is used, the thickness can be reduced and the size can be reduced.

In the present invention, preferably, the air layer is formed of a plate-like member, and the exhaust gas inflow prevention portion is a wall portion formed by bending the upper end of the plate-like member.
In the present invention configured as described above, the exhaust gas inflow prevention portion is formed by the wall portion formed by bending the upper end of the plate-like member. Therefore, the exhaust gas inflow prevention portion is formed with a simple structure. be able to.

In the present invention, the air layer is preferably formed on the side along the longitudinal direction of the fuel cell assembly.
In the present invention configured as described above, when the fuel cell assembly is long in the longitudinal direction, the temperature of the central portion becomes higher than the temperatures of both end portions. Since it is formed on the side along the longitudinal direction of the battery cell assembly, the temperature in the air layer is made uniform by heat diffusion of the high-temperature air in the central portion in the air layer to both end portions. Therefore, this makes it possible to suppress variations in the temperature of the fuel cell assembly.

In the present invention, the air layer is preferably formed on four sides of the fuel cell assembly.
In the present invention configured as described above, since the fuel cell assembly is formed on the four sides, almost the entire area of the fuel cell assembly is surrounded by the air layer, and further, the air layer is formed in the almost entire area. Since the inside temperature is made uniform, it is possible to more effectively suppress variations in temperature of the fuel cell assembly.

  According to the fuel cell module of the present invention, it is possible to reduce the size and prevent variations in temperature of the fuel cell assembly.

1 is an overall configuration diagram showing a solid oxide fuel cell (SOFC) including a fuel cell module according to an embodiment of the present invention. It is a perspective view which shows the fuel electromagnetic module by one Embodiment of this invention. It is front sectional drawing which shows the fuel cell module by one Embodiment of this invention. FIG. 4 is a sectional view taken along line IV-IV in FIG. 3. It is sectional drawing which expands and shows the A section of FIG. It is sectional drawing seen along the VI-VI line of FIG.

Next, a solid oxide fuel cell (SOFC) fuel cell module 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 (SOFC) equipped with a fuel cell module according to an embodiment of the present invention. As shown in FIG. 1, a solid oxide fuel cell (SOFC) 1 includes a fuel cell module 2 and an auxiliary unit 4.

  The fuel cell module 2 includes a housing 6, and a sealed space 8 is formed inside the housing 6. A fuel cell assembly 12 that performs a power generation reaction with fuel gas and oxygen-containing gas (air) is disposed in a power generation chamber 10 that is a lower portion of the sealed space 8. The fuel cell assembly 12 includes ten fuel cell stacks 14, and the fuel cell stack 14 includes 16 fuel cells 16. Thus, the fuel cell assembly 12 has 160 fuel cells 16, and all of these fuel cells 16 are connected in series.

A combustion chamber 18 is formed above the above-described power generation chamber 10 in the sealed space 8 of the fuel cell module 2. In this combustion chamber 18, the remaining fuel gas that has not been used for the power generation reaction and the remaining oxygen-containing gas ( Air) is combusted to generate exhaust gas.
Further, a reformer 20 for reforming the fuel gas is disposed above the combustion chamber 18, and the reformer 20 is heated to a temperature at which a reforming reaction can be performed by the fuel heat of the remaining fuel gas. is doing. Furthermore, an air heat exchanger 22 for receiving combustion heat and heating power generation air is disposed above the reformer 20.

  Next, the auxiliary unit 4 stores a pure water tank 26 that stores water from a water supply source 24 such as tap water and uses the filter to obtain pure water, and a water flow rate that adjusts the flow rate of the water supplied from the water storage tank. An adjustment unit 28 (such as a “water pump” driven by a motor) is provided. The auxiliary unit 4 also includes a gas shut-off valve 32 that shuts off the fuel gas supplied from a fuel supply source 30 such as city gas, a desulfurizer 36 for removing sulfur from the fuel gas, and a flow rate of the fuel gas. A fuel flow rate adjusting unit 38 (such as a “fuel pump” driven by a motor) is provided. Further, the auxiliary unit 4 includes an electromagnetic valve 42 that shuts off air that is an oxygen-containing gas supplied from an air supply source 40, and a reforming air flow rate adjustment unit 44 that adjusts the flow rate of air (driven by a motor). “Air blower” and the like, a power generation air flow rate adjustment unit 45 (such as an “air blower” driven by a motor), a first heater 46 for heating the reforming air supplied to the reformer 20, and power generation And a second heater 48 for heating the power generation air supplied to the chamber. The first heater 46 and the second heater 48 are provided in order to efficiently raise the temperature at startup, but may be omitted.

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

  Next, the internal structure of the fuel cell module according to the embodiment of the present invention will be described with reference to FIGS. 2 is a perspective view showing a fuel electromagnetic module according to an embodiment of the present invention, FIG. 3 is a front sectional view showing a fuel cell module according to an embodiment of the present invention, and FIG. FIG. 5 is an enlarged cross-sectional view showing a part A of FIG. 4, and FIG. 6 is a cross-sectional view taken along the line VI-VI of FIG. 3.

  As shown in FIGS. 2 to 4, in the sealed space 8 in the housing 6 of the fuel cell module 2, as described above, the fuel cell assembly 12, the reformer 20, and the air heat exchange are sequentially performed from below. A vessel 22 is arranged.

  The reformer 20 is provided with a pure water introduction pipe 60 for introducing pure water and a reformed gas introduction pipe 62 for introducing reformed fuel gas and reforming air to the upstream end side thereof. In addition, in the reformer 20, an evaporation unit 20a and a reforming unit 20b are formed in order from the upstream side, and the reforming unit 20b is filled with a reforming catalyst. The fuel gas and air mixed with the steam (pure water) introduced into the reformer 20 are reformed by the reforming catalyst filled in the reformer 20. As the reforming catalyst, a catalyst obtained by imparting nickel to the alumina sphere surface or a catalyst obtained by imparting ruthenium to the alumina sphere surface is appropriately used.

  A fuel gas supply pipe 64 is connected to the downstream end side of the reformer 20, and the fuel gas supply pipe 64 extends downward and further in an manifold 66 formed below the fuel cell assembly 12. It extends horizontally. A plurality of fuel supply holes 64 b are formed in the lower surface of the horizontal portion 64 a of the fuel gas supply pipe 64, and the reformed fuel gas is supplied into the manifold 66 from the fuel supply holes 64 b.

  A lower support plate 68 having a through hole for supporting the fuel cell stack 14 described above is attached above the manifold 66, and the fuel gas in the manifold 66 is supplied into the fuel cell 16. Is done.

  Next, an air heat exchanger 22 is provided above the reformer 20. The air heat exchanger 22 includes an air aggregation chamber 70 on the upstream side and two air distribution chambers 72 on the downstream side. The air aggregation chamber 70 and the air distribution chamber 72 include six air flow path tubes 74. Connected by. Here, as shown in FIG. 3, three air flow path pipes 74 form a set (74a, 74b, 74c, 74d, 74e, 74f), and the air in the air collecting chamber 70 is in each set. It flows into each air distribution chamber 72 from the air flow path pipe 74.

The air flowing through the six air flow path pipes 74 of the air heat exchanger 22 is preheated by exhaust gas that burns and rises in the combustion chamber 18.
An air introduction pipe 76 is connected to each of the air distribution chambers 72, the air introduction pipe 76 extends downward, and the lower end side communicates with the lower space of the power generation chamber 10, and the air that has been preheated in the power generation chamber 10. Is introduced.

Next, an exhaust gas chamber 78 is formed below the manifold 66. Further, as shown in FIG. 4, an exhaust gas discharge passage 80 extending in the vertical direction is formed inside the front surface 6 a and the rear surface 6 b which are surfaces along the longitudinal direction of the housing 6. The upper end side communicates with the space above the power generation chamber 10 in which the air heat exchanger 22 (air flow pipe 78) is disposed, and the lower end side communicates with the exhaust gas chamber 78. Further, an exhaust gas discharge pipe 82 is connected to substantially the center of the lower surface of the exhaust gas chamber 78, and the downstream end of the exhaust gas discharge pipe 82 is connected to the above-described hot water producing apparatus 50 shown in FIG.
As shown in FIG. 3, an ignition device 83 for starting combustion of fuel gas and air is provided in the combustion chamber 18.

  Further, as shown in FIG. 4, an air layer 84 is formed in the space between the exhaust gas discharge path 80 and the power generation chamber 8. Since the fuel cell assembly 12 has a rectangular shape in plan view, the air layer 84 is provided at two locations on the front side and the rear side along the longitudinal direction of the fuel cell assembly 12. (See FIG. 6).

As shown in FIG. 6, these air layers 84 include a first plate-like member 86 provided on the front side and the rear side of the power generation chamber 8 and along the longitudinal direction of the fuel cell assembly 12, and exhaust gas discharge. It is formed from the 2nd plate-shaped member 88 which functions as an internal side wall of the path | route 80. FIG.
Specifically, as shown in FIG. 5, the distal end portion of the first plate-like member 86 is bent outward, then the second plate-like member 88 is bent inward, and these two plate-like members 86 are bent. , 88 form a wall 90. The wall 90 prevents the exhaust gas from flowing into the air layer 84.

Next, the operation (operation) of the fuel cell module according to the above-described embodiment will be described.
First, in the present embodiment, since the air layer 84 is formed in the space between the exhaust gas discharge path 80 and the power generation chamber 10, the air layer 84 has a heat insulating function, whereby the power generation chamber 10 is exhausted. It is insulated from the gas discharge path 80, and the temperature fall of the power generation chamber 10 can be prevented.
Next, the fuel cell assembly 12 has a relatively high temperature at the center and a relatively low temperature at the end in the lateral direction, and there are variations in temperature. Therefore, when heat is transferred from the power generation chamber 10 to the air layer 84, the air in the air layer 84 is also relatively hot at the center and relatively cold at the end, but the air in FIG. As indicated by the arrow B, the temperature of the air in the air layer 84 is made uniform because the high temperature region 80a moves to the low temperature region 80b. Thereby, the variation in the temperature of the fuel cell assembly 12 can be suppressed. Furthermore, since the wall portion 90 which is an exhaust gas inflow prevention portion is provided, the exhaust gas is prevented from flowing into the air layer 84, so that the exhaust gas flows into the air layer 84 and the local temperature. This variation does not occur.
Further, since the air layer 84 is used instead of the heat insulating material, the thickness can be reduced, and the entire apparatus becomes compact.

  Next, the air layer 84 is formed by the first plate-like member 86 and the second plate-like member 88, and the wall portion 90 which is an exhaust gas inflow prevention portion is formed by bending the upper ends of these plate-like members 86, 88. Therefore, the exhaust gas inflow prevention portion can be formed with a simple structure.

  In the embodiment described above, the fuel cell assembly is rectangular, but when the fuel cell has a square shape or a shape close thereto, an exhaust gas discharge path is provided on all four sides, and this exhaust An air chamber may be formed on four sides between the gas discharge path and the power generation chamber. In this case, since the air chambers are formed on the four sides of the fuel cell assembly, almost the entire area of the fuel cell assembly is surrounded by the air layer. Since the temperature is made uniform, it is possible to more effectively suppress the temperature variation of the fuel cell assembly.

1 Solid oxide fuel cell (SOFC)
2 Fuel cell module 6 Housing 10 Power generation chamber 12 Fuel cell assembly 14 Fuel cell stack 16 Fuel cell 18 Combustion chamber 80 Exhaust gas discharge passage 84 Air layer 86 First plate member 88 Second plate member 90 Wall

Claims (4)

In a fuel cell module comprising a fuel cell assembly having a plurality of fuel cells operating with a fuel gas and an oxygen-containing gas,
A power generation chamber in which the fuel cell assembly is disposed;
An exhaust gas exhaust passage for exhausting exhaust gas generated by combustion of the fuel gas and oxygen-containing gas not used in the operation of the fuel cell from the upper space of the power generation chamber;
An air layer formed in a space between the exhaust gas discharge path and the power generation chamber,
A fuel cell module, wherein an exhaust gas inflow prevention portion for preventing inflow of exhaust gas into the air layer is formed at a portion of the air layer in contact with the exhaust gas discharge path.   2. The fuel cell module according to claim 1, wherein the air layer is formed of a plate-like member, and the exhaust gas inflow prevention portion is a wall portion formed by bending the upper end of the plate-like member.   The fuel cell module according to claim 1, wherein the air layer is formed on a side of the fuel cell assembly along the longitudinal direction.   The fuel cell module according to claim 1, wherein the air layer is formed on four sides of the fuel cell assembly.

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