JP2021051923A - Fuel cell system - Google Patents

Abstract

To provide a fuel cell system capable of efficiently supplying heat from a combustor to a reformer.SOLUTION: A combustor 7 included in a fuel cell system 1 burns off-fuel containing fuel gas which has not been consumed by a fuel cell stack 2 and off-air containing oxidant gas which has not been consumed by the fuel cell stack 2. A dividing member 33 equipped in the combustor 7 divides an internal space 50 of the combustor 7 into a first chamber 51 and a second chamber 52. A first off-air supply port 41 supplies off-air to the first chamber 51. A second off-air supply port 42 supplies off-air to the second chamber 52. An off-fuel supply port 43 supplies off-fuel to the second chamber 52. An off-air discharge port 44 discharges off-air from the first chamber 51 to a combustion region 53 of the second chamber 52. Structures 45, 47, and 333 are provided in the internal space 50 of the combustor 7, and are configured to supply the heat of the combustion gas burned by the off-fuel and the off-air to a reformer 4.SELECTED DRAWING: Figure 4

Description

The present invention relates to a fuel cell system.

Conventionally, a fuel cell system that generates electricity by an electrochemical reaction between a fuel gas and an oxidant gas is known. The fuel cell system burns off-fuel and off-air discharged without being consumed by the fuel cell stack in a combustor, and supplies the heat of the combustion gas to a reformer or the like. The reformer reacts raw fuel gas such as city gas with water vapor by a catalyst to reform the fuel gas to be supplied to the fuel cell.

The fuel cell system described in Patent Document 1 has a configuration in which off-fuel discharged from the fuel cell stack and raw fuel gas are merged by an ejector, supplied to the fuel cell stack again through a reformer, and used for power generation. ing.

JP-A-2018-206685

The inventors of the present invention have found the following problems in the fuel cell system. That is, in a fuel cell system, when the fuel gas is consumed for power generation in the fuel cell stack and the amount of off-fuel burned in the combustor decreases, the amount of heat supplied from the combustor to the reformer becomes insufficient or modified. There is a problem that a temperature distribution occurs in the pledge. Further, the same problem occurs when the amount of heat transferred from the housing of the combustor to the part other than the reformer (for example, the combustor for warming up) increases. In that case, the reforming reaction of the fuel by the catalyst of the reformer deteriorates, and the power generation efficiency may decrease.

In view of the above points, an object of the present invention is to provide a fuel cell system capable of efficiently supplying heat from a combustor to a reformer.

In order to achieve the above object, the fuel cell system according to claim 1 includes a fuel cell stack (2), a reformer (4) and a combustor (7). The fuel cell stack generates electricity by reacting the fuel gas with the oxidant gas. The reformer reforms the source fuel into fuel gas that supplies the fuel cell stack. The combustor burns off-fuel containing fuel gas not consumed in the fuel cell stack and off-air containing oxidant gas not consumed in the fuel cell stack.
The combustor includes a housing (32), a dividing member (33), a first off air supply port (41), a second off air supply port (42), an off fuel supply port (43), and an off air discharge port ( 44) and structures (45, 47, 333). The housing forms the internal space (50) of the combustor. The dividing member divides the internal space of the combustor into a first chamber (51) and a second chamber (52). The first off-air supply port supplies off-air to the first chamber. The second off-air supply port supplies off-air to the second chamber. The off-fuel supply port supplies off-fuel to the second chamber. The off-air outlet discharges off-air from the first chamber to the combustion region (53) where the off-fuel burns in the second chamber. The structure is provided in the internal space of the combustor, and is configured to supply the heat of the combustion gas burned by the off-fuel and the off-air to the reformer.

According to this, the combustor can efficiently supply the heat of the combustion gas to the reformer by the structure provided in the internal space. Therefore, even if the amount of off-fuel supplied to the combustor is reduced, the shortage of heat supply from the combustor to the reformer can be prevented. Therefore, in this fuel cell system, the combustion gas is satisfactorily generated by the reformer, so that the power generation efficiency can be improved.

The fuel cell system according to claim 10 includes a fuel cell stack (2), a reformer (4), a warm-up combustor (8), a combustor (7), and a heat recovery structure (60, 62). Be prepared. The fuel cell stack generates electricity by reacting the fuel gas with the oxidant gas. The reformer reforms the source fuel into fuel gas that supplies the fuel cell stack. The warm-up combustor burns the source fuel and air by igniting the spark plug (24). The combustor burns off-fuel containing fuel gas not consumed in the fuel cell stack and off-air containing oxidant gas not consumed in the fuel cell stack.
The combustor includes a housing (32), a dividing member (33), a first off air supply port (41), a second off air supply port (42), an off fuel supply port (43), and an off air discharge port ( 44). The housing forms the internal space (50) of the combustor. The dividing member divides the internal space of the combustor into a first chamber (51) and a second chamber (52). The first off-air supply port supplies off-air to the first chamber. The second off-air supply port supplies off-air to the second chamber. The off-fuel supply port supplies off-fuel to the second chamber. The off-air outlet discharges off-air from the first chamber to the combustion region (53) where the off-fuel burns in the second chamber.
The heat recovery structure is configured to recover the radiant heat radiated from the housing of the combustor to a portion other than the reformer and return it to the internal space of the combustor.

According to this, the radiant heat radiated from the housing of the combustor to the part other than the reformer is recovered by the heat recovery structure and returned to the internal space of the combustor, so that it is supplied from the combustor to the reformer. Increases the amount of heat generated. Therefore, even if the amount of off-fuel supplied to the combustor is reduced, the shortage of heat supply from the combustor to the reformer can be prevented. Therefore, in this fuel cell system, the combustion gas is satisfactorily generated by the reformer, so that the power generation efficiency can be improved.

The fuel cell system according to claim 13 includes a fuel cell stack (2), a reformer (4), a warm-up combustor (8), a combustor (7), and a heat supply structure (71, 72, 431). ) Is provided. The fuel cell stack generates electricity by reacting the fuel gas with the oxidant gas. The reformer reforms the source fuel into fuel gas that supplies the fuel cell stack. The warm-up combustor burns the source fuel and air by igniting the spark plug (24). The combustor burns off-fuel containing fuel gas not consumed in the fuel cell stack and off-air containing oxidant gas not consumed in the fuel cell stack.
The combustor includes a housing (32), a dividing member (33), a first off air supply port (41), a second off air supply port (42), an off fuel supply port (43), and an off air discharge port ( 44). The housing forms the internal space (50) of the combustor. The dividing member divides the internal space of the combustor into a first chamber (51) and a second chamber (52). The first off-air supply port supplies off-air to the first chamber. The second off-air supply port supplies off-air to the second chamber. The off-fuel supply port supplies off-fuel to the second chamber. The off-air outlet discharges off-air from the first chamber to the combustion region (53) where the off-fuel burns in the second chamber.
Then, the heat supply structure supplies a part of the heat of the combustion gas burned by the warm-up combustor to the combustor.

By the way, when the heat of the internal space of the combustor is concentrated on the reformer side as in the invention of claim 1, the temperature near the off-fuel supply port in the internal space drops, and the fuel The ignitability of the combustor may decrease when the battery system is started.
Therefore, in the invention according to claim 13, when the fuel cell system is started, a part of the heat of the combustion gas burned by the warm-up combustor is supplied to the combustor by the heat supply structure to raise the temperature of the combustor. As a result, the combustor can be ignited in a stable manner.
In the heat supply structure, it is possible to create a fire in the combustor by raising the temperature of a part of the internal space of the combustor. Therefore, the physique of the heat supply structure can be made relatively small. Therefore, when the warm-up combustor is stopped during power generation, it is possible to prevent heat from escaping from the combustor to the warm-up combustor side via the heat supply structure.

The fuel cell system of claim 17 includes a fuel cell stack (2), a reformer (4) and a combustor (7). The fuel cell stack generates electricity by reacting the fuel gas with the oxidant gas. The reformer reforms the source fuel into fuel gas that supplies the fuel cell stack. The combustor burns off-fuel containing fuel gas not consumed in the fuel cell stack and off-air containing oxidant gas not consumed in the fuel cell stack.
The combustor includes a housing (32), a dividing member (33), a first off air supply port (41), a second off air supply port (42), an off fuel supply port (43), and an off air discharge port ( It has 44) and an oxidation catalyst (73). The housing forms the internal space (50) of the combustor. The dividing member divides the internal space of the combustor into a first chamber (51) and a second chamber (52). The first off-air supply port supplies off-air to the first chamber. The second off-air supply port supplies off-air to the second chamber. The off-fuel supply port supplies off-fuel to the second chamber. The off-air outlet discharges off-air from the first chamber to the combustion region (53) where the off-fuel burns in the second chamber. The oxidation catalyst is provided in the vicinity of some of the off-fuel supply ports of the plurality of off-fuel supply ports.

According to this, it is possible to ignite the off-fuel blown out from the off-fuel supply port in the vicinity where the oxidation catalyst is provided at a relatively low temperature to produce a fire. By transferring the fire to the off-fuel blown out from the other off-fuel supply port, it is possible to burn the entire combustion region of the combustor. Therefore, this fuel cell system can stably ignite the combustor at startup.

The reference reference numerals in parentheses attached to each component or the like indicate an example of the correspondence between the component or the like and the specific component or the like described in the embodiment described later.

It is a block diagram of the fuel cell system which concerns on 1st Embodiment. It is sectional drawing which shows a part of the hot module provided in the fuel cell system. It is sectional drawing which shows the combustor which a fuel cell system has, and its vicinity. It is a perspective view which shows the combustor provided in the fuel cell system. It is a top view which shows only the combustor in the VV line of FIG. It is a simulation figure which shows the distribution of the excess air ratio in a combustor. It is a simulation figure which shows the distribution of the excess air ratio in a combustor. It is sectional drawing which shows the combustor provided in the fuel cell system which concerns on 2nd Embodiment, and the vicinity thereof. It is a simulation figure which shows the temperature distribution in a combustor. It is a graph comparing the temperature of the wall on the reformer side of the housing of the combustor with respect to the fuel cell system according to the second embodiment and the fuel cell stem of the first comparative example. It is sectional drawing which shows the combustor provided in the fuel cell system which concerns on 3rd Embodiment, and the vicinity thereof. It is a schematic diagram which showed the flow direction of off fuel and 1st off air in a combustor. It is sectional drawing which shows a part of the hot module included in the fuel cell system which concerns on 4th Embodiment. It is a graph which compared the wall surface temperature of the warm-up combustor with respect to the fuel cell system which concerns on 4th Embodiment, and the fuel cell stem of 2nd comparative example. It is sectional drawing which shows a part of the hot module included in the fuel cell system which concerns on 5th Embodiment. It is a graph comparing the wall surface temperature on the off-air passage side of the housing of the combustor with respect to the fuel cell system according to the fifth embodiment and the fuel cell stem of the third comparative example. It is sectional drawing which shows a part of the hot module included in the fuel cell system which concerns on 6th Embodiment. It is a graph comparing the wall surface temperature on the off-air passage side of the housing of the combustor with respect to the fuel cell system according to the sixth embodiment and the fuel cell stem of the fourth comparative example. It is sectional drawing which shows a part of the hot module included in the fuel cell system which concerns on 7th Embodiment. It is a simulation figure which shows the temperature distribution in a combustor. It is sectional drawing which shows the combustor provided in the fuel cell system which concerns on 8th Embodiment, and the vicinity thereof. FIG. 2 is a plan view showing only the combustor at the position of the line XXII-XXII in FIG. It is sectional drawing which shows the combustor provided in the fuel cell system which concerns on 9th Embodiment, and the vicinity thereof. It is a top view which shows only the combustor at the position of line XXIV-XXIV of FIG. 6 is a graph comparing the relationship between the off-fuel temperature and the combustion rate of the fuel cell system according to the ninth embodiment and the fuel cell stem of the fifth comparative example.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In each of the following embodiments, the same or equal parts are designated by the same reference numerals, and the description thereof will be omitted.

(First Embodiment)
The first embodiment will be described with reference to the drawings. As shown in FIG. 1, the fuel cell system 1 of the present embodiment includes a fuel cell stack 2, an ejector 3, a reformer 4, an evaporator 5, an air preheater 6, a combustor 7, a warm-up combustor 8, and the like. It has. The combustor 7 is sometimes called an off-gas burner, and the warm-up combustor 8 is sometimes called a warm-up burner.

The fuel cell stack 2 is supplied with a fuel gas generated by steam reforming a raw material gas such as city gas and air as an oxidant gas (specifically, oxygen in the air).

Natural gas such as city gas is a gas containing hydrocarbons (for example, methane). The raw fuel gas flows through the fuel supply path 10 by driving the fuel blower 9, and is introduced into the reformer 4 via the ejector 3. A steam path 11 extending from the evaporator 5 is connected between the fuel blower 9 and the ejector 3 in the fuel supply path 10. Water is supplied to the evaporator 5 by driving the pump 12. The water supplied to the evaporator 5 is heated by the heat of the combustion gas discharged from the combustor 7, becomes steam, and is mixed with the raw fuel gas flowing through the fuel supply path 10.

The ejector 3 has an inlet 13, a suction port 14, and a discharge port 15. A mixed gas of raw fuel gas and water vapor is supplied to the inlet 13 of the ejector 3. A recycling passage 16 is connected to the suction port 14 of the ejector 3. A part of off-fuel including fuel gas not consumed by the fuel cell stack 2 flows through the recycling passage 16. The reformer 4 is connected to the passage 17 on the discharge port 15 side of the ejector 3. The ejector 3 uses a mixed gas of raw fuel gas and water vapor supplied to the inlet 13 as a drive flow, sucks off fuel flowing through the recycling passage 16 from the suction port 14, and modifies the mixed gas from the discharge port 15. Discharge to the pawnbroker 4.

In the reformer 4, the mixed gas of the raw fuel gas, the off-fuel, and the steam and the catalyst are heated to a temperature at which the steam reforming reaction is possible by the heat of the combustion gas discharged from the combustor 7. Then, the raw material fuel gas and steam react in the presence of the catalyst contained in the reformer 4 and are reformed into a fuel gas containing hydrogen and carbon monoxide. The fuel gas is supplied to a fuel electrode (not shown) of the fuel cell stack 2.

The air used as the oxidant gas supplied to the fuel cell stack 2 is taken in from the outside air by driving the air blower 18. The air is heated by the heat of the combustion gas discharged from the combustor 7 when flowing through the air preheater 6 provided in the middle of the air supply path 19. The air heated by the air preheater 6 is supplied to an air electrode (not shown) of the fuel cell stack 2.

The fuel cell stack 2 is also called a cell stack, and is an aggregate of a plurality of fuel cell cells (not shown). The fuel cell is, for example, a solid oxide fuel cell (SOFC) in which a fuel electrode (that is, an anode) is formed on one side of an electrolyte and an air electrode is formed on the other surface. (That is, the cathode) is formed. The fuel cell stack 2 generates electricity by an electrochemical reaction between the fuel gas supplied to the fuel electrode and air (specifically, oxygen in the air) as an oxidant gas supplied to the air electrode.

The off-air containing the oxidant gas that has not been consumed in the fuel cell stack 2 is supplied to the combustor 7 via the off-air passage 20. Further, the off-fuel containing the fuel gas not consumed in the fuel cell stack 2 passes through the off-fuel passage 21, and a part of the off-fuel is supplied to the combustor 7.

The part in the middle of the off-fuel passage 21 and the suction port 14 of the ejector 3 are connected by the recycling passage 16 described above. Therefore, the other part of the off-fuel flowing through the off-fuel passage 21 is sucked into the ejector 3 via the recycling passage 16. That is, the fuel cell system 1 includes the ejector 3, recycles the off-fuel discharged from the fuel cell stack 2, mixes the raw fuel gas and the steam, and returns the off fuel to the fuel cell stack 2 through the reformer 4. By supplying it, it is configured to be used repeatedly for power generation.

The combustor 7 is configured to burn off fuel and off air supplied from the fuel cell stack 2 by self-ignition in a high temperature field. The combustion gas generated by combustion of off-fuel and off-air in the combustor 7 is discharged to the combustion gas passage 23 from the combustion gas outlet 22 of the combustor 7. The combustor 7 and the combustion gas passage 23 are provided so as to be able to supply the heat of the combustion gas to the reformer 4, the air preheater 6, and the evaporator 5. Therefore, the catalyst of the reformer 4, the source fuel gas and steam flowing through the catalyst, the air flowing through the air preheater 6, and the water supplied to the evaporator 5 flow through the combustor 7 and the combustion gas passage 23. It is heated by the heat of the combustion gas.

The warm-up combustor 8 operates when the fuel cell system 1 is started. City gas and air are supplied to the warm-up combustor 8. The warm-up combustor 8 ignites and burns a mixed gas of city gas and air by a spark plug 24, and heats the fuel cell stack 2 by the heat of the combustion gas. The warm-up combustor 8 stops operating during power generation that continues when the fuel cell system 1 is started.

In the present embodiment, the fuel cell stack 2, the reformer 4, the evaporator 5, the ejector 3, the air preheater 6, the combustor 7, and the warm-up combustor 8 described above are configured as the hot module 25.

Next, a specific configuration of the hot module 25 included in the fuel cell system 1 of the present embodiment will be described with reference to FIGS. 2 to 5. In the following description, the terms "upper" and "lower" are used for convenience of explanation, and do not limit the direction in which each member is installed.

As shown in FIG. 2, a warm-up combustor 8 formed in a bottomed tubular shape is provided in the central portion of the hot module 25. In the warm-up combustor 8, city gas is supplied to the fuel supply unit 26, and air is supplied to the mixing chamber 28. The city gas and air are mixed in the mixing chamber 28 and then supplied from the mixing chamber to the warm-up combustion chamber 29. In the warm-up combustion chamber 29, the mixed gas is burned by the ignition of the spark plug 24. The combustion gas burned in the warm-up combustion chamber 29 flows around the fuel cell stack 2 through the warm-up combustion gas passage 30, and is used for warming up the fuel cell stack 2.

A combustor 7 is provided on the radial outer side of the warm-up combustor 8. Specifically, the combustor 7 is provided on the outer side in the radial direction with respect to a virtual cylindrical surface (not shown) extending the outer edge of the warm-up combustor 8 in the axial direction. The combustor 7 is provided in an annular shape on the radial outer side of the warm-up combustor 8.

An off-air passage 20 through which the off-air discharged from the air electrode of the fuel cell stack 2 flows is provided below the warm-up combustor 8 and inside the combustor 7 in the radial direction. Further, on the lower side of the combustor 7, an off-fuel passage 21 through which the off-fuel discharged from the fuel electrode of the fuel cell stack 2 flows is provided.

The off-fuel supplied from the off-fuel passage 21 to the combustor 7 and the off-air supplied from the off-air passage 20 to the combustor 7 are combusted in the internal space 50 of the combustor 7 by self-ignition. Above the combustor 7, a tubular combustion gas passage 23 communicating with the combustion gas outlet 22 of the combustor 7 is provided.

A reformer 4 is provided on the radial outer side of the combustor 7 and the combustion gas passage 23. The reformer 4 is provided with a catalyst. The reformer 4 is configured such that the fuel gas supplied from the ejector 3 and water vapor flow through the catalyst from top to bottom. A heat insulating material 31 is provided above the combustor 7 and inside the combustion gas passage 23 in the radial direction.

An evaporator 5 is provided above the combustion gas passage 23 and the reformer 4. The hot module 25 is configured such that the combustion gas flowing through the combustion gas passage 23 flows through the flow path 27 below the evaporator 5 and then is discharged to the outside air.

As shown in FIGS. 3 to 5, the combustor 7 includes a housing 32, a dividing member 33, a first off air supply port 41, a second off air supply port 42, an off fuel supply port 43, and an off air discharge port 44. , And a plurality of guide plates 45 as a structure and the like.

The housing 32 constitutes the outer shell of the combustor 7. An internal space 50 is formed inside the housing 32. The housing 32 is formed in an annular shape. Therefore, the internal space 50 of the housing 32 is also formed in an annular shape. The reformer 4 is provided on the outside (diameter outside) of the radial outer wall of the housing 32. On the other hand, an off-air passage 20 is provided on the outside (diametrically inside) of the radial inner wall of the housing 32. Further, an off-fuel passage 21 is provided on the outside (lower side) of the lower wall of the combustor 7.

In the following description, the radial outer wall of the housing 32 is the “wall 34 on the reformer 4 side of the housing 32”, and the radial inner wall of the housing 32 is “the off-air passage 20 side of the housing 32”. Wall 35 ". Further, the lower wall of the housing 32 is referred to as "lower wall 36 of the housing 32", and the upper wall of the housing 32 is referred to as "upper wall 37 of the housing 32".

The internal space 50 is provided with a dividing member 33 that divides the internal space 50 into a first chamber 51 and a second chamber 52. The dividing member 33 is composed of an upper dividing member 38 and a lower dividing member 39. The upper dividing member 38 has an annular plate 381 formed in an annular shape and an upper tubular portion 382 extending in a tubular shape from the outer outer edge of the annular plate 381 in the radial direction toward the lower wall 36 of the housing 32. There is. The radial inner portion of the annular plate 381 is connected to the wall 35 on the off-air passage 20 side of the housing 32.

The lower dividing member 39 has a connecting portion 391 connected to the lower wall 36 of the housing 32, and a lower tubular portion 392 extending in a tubular shape from the connecting portion 391 toward the annular plate 381 side. A predetermined gap is provided between the upper cylinder portion 382 of the upper division member 38 and the lower cylinder portion 392 of the lower division member 39. This gap is called an off-air outlet 44.

In the internal space 50, the first chamber 51 is one of the radial inner surfaces of the upper cylinder portion 382 and the lower cylinder portion 392, the lower surface of the annular plate 381, and the wall 35 on the off-air passage 20 side of the housing 32. It is a space partitioned by a portion and a part of the lower wall 36 of the housing 32. On the other hand, in the internal space 50, the second room 52 is a space other than the first room 51. Specifically, the second chamber 52 includes a radial outer surface of the upper cylinder portion 382 and the lower cylinder portion 392, an upper surface of the annular plate 381, a wall 34 on the reformer 4 side of the housing 32, and a housing. It is a space partitioned by an upper wall 37 of the body 32, a part of the wall 35 on the off-air passage 20 side of the housing 32, and a part of the lower wall 36 of the housing 32.

A plurality of first off-air supply ports 41 and a plurality of second off-air supply ports 42 are provided on the wall 35 on the off-air passage 20 side of the housing 32. The plurality of first off-air supply ports 41 are provided on the wall 35 on the off-air passage 20 side of the housing 32 below the position where the annular plate 381 is connected. The plurality of first off-air supply ports 41 are provided side by side in the circumferential direction of the combustor 7. The first off-air supply port 41 communicates the off-air passage 20 with the first chamber 51. Therefore, the first off-air supply port 41 can supply off-air from the off-air passage 20 to the first chamber 51. In the following description, the off air supplied from the first off air supply port 41 to the first chamber 51 is referred to as "first off air".

The plurality of second off-air supply ports 42 are provided above the position where the annular plate 381 is connected to the wall 35 on the off-air passage 20 side of the housing 32. The plurality of second off-air supply ports 42 are provided side by side in the circumferential direction of the combustor 7. The second off-air supply port 42 communicates the off-air passage 20 with the second chamber 52. Therefore, the second off-air supply port 42 can supply off-air from the off-air passage 20 to the second chamber 52. The opening area of the second off-air supply port 42 is formed to be larger than the opening area of the first off-air supply port 41. In the following description, the off air supplied from the second off air supply port 42 to the second chamber 52 is referred to as "second off air".

A plurality of off-fuel supply ports 43 are provided on the lower wall 36 of the housing 32. The plurality of off-fuel supply ports 43 are radially outside of the lower wall 36 of the housing 32 with respect to the connecting portion 391 of the lower dividing member 39 (that is, the housing 32 is modified from the connecting portion 391 of the lower dividing member 39). It is provided on the wall 34 side on the pawnbroker 4 side). The plurality of off-fuel supply ports 43 are provided side by side in the circumferential direction of the combustor 7. The off-fuel supply port 43 communicates the off-fuel passage 21 with the second chamber 52. As a result, the off-fuel supply port 43 can supply off-air from the off-fuel passage 21 to the second chamber 52.

The off-fuel supplied from the off-fuel supply port 43 to the second chamber 52 has an air-fuel ratio (mass of off-air / off) in which the temperature of the combustion region 53 of the internal space 50 of the combustor 7 is equal to or higher than the self-ignition temperature. If the fuel mass) is within the combustible range, it will burn by self-ignition. The combustion region 53 refers to a region where off-fuel burns in the second chamber 52. In FIG. 3, the combustion region 53 is schematically shown by a broken line.

The first off-air supplied from the first off-air supply port 41 to the first chamber 51 is discharged from the first chamber 51 toward the combustion region 53 via the off-air discharge port 44. Therefore, by appropriately controlling the amount of air of the first off-air discharged from the off-air discharge port 44 to the combustion region 53, the air-fuel ratio of the combustion region 53 becomes a combustible range, and the off-fuel supply port 43 to the first The off-fuel supplied to the two chambers 52 burns.

A plurality of guide plates 45 as a structure are provided in the second chamber 52 of the internal space 50 of the combustor 7. The plurality of guide plates 45 have a shape cut up from an annular plate member 46. The plurality of guide plates 45 are provided so as to be arranged in the circumferential direction on the annular plate 381 included in the upper dividing member 38. Further, the plurality of guide plates 45 are provided so as to be inclined in the circumferential direction with respect to the radial direction of the internal space 50. As a result, the second off-air supplied from the plurality of second off-air supply ports 42 to the second chamber 52 is guided by the plurality of guide plates 45 so that the flow direction is directed in the circumferential direction. Then, as shown by the arrow SW1 in FIG. 5, the second off-air guided by the plurality of guide plates 45 is mixed with the combustion gas and is second along the wall 34 on the reformer 4 side of the housing 32. It flows so as to circulate in the chamber 52. Therefore, the heat of the combustion gas is efficiently supplied to the reformer 4, and the temperature distribution in the circumferential direction of the reformer 4 is reduced.

6 and 7 are simulation diagrams showing the distribution of the excess air ratio in the second chamber 52 of the combustor 7.
As shown in FIGS. 6 and 7, the region above the upper dividing member 38 in the second chamber 52 of the combustor 7 is a region having a large excess air ratio λ (that is, fuel lean). That is, the second off air is flowing in this region.
Further, in the second chamber 52, the region directly above the off fuel supply port 43 (that is, the combustion region 53) is a region where the excess air ratio λ is small (that is, fuel rich). That is, the combustion gas that burns in the combustion region 53 flows in this region.
Then, as shown by the arrows SW2 in FIGS. 6 and 7, in the region outside the combustion region 53 in the second chamber 52 in the radial direction, the second off-air flows in the circumferential direction, and the second off air flows along with the flow. The combustion gas is flowing in the circumferential direction while being mixed with the second off air.

The fuel cell system 1 of the first embodiment described above has the following effects.
(1) In the first embodiment, the plurality of guide plates 45 as a structure provided in the internal space 50 of the combustor 7 supply the heat of the combustion gas burned in the combustor 7 to the reformer 4. It is configured.
As a result, even if the fuel gas is repeatedly used for power generation in the fuel cell stack 2 and the off-fuel supplied to the combustor 7 is reduced, the heat of the combustion gas is efficiently supplied from the combustor 7 to the reformer 4. Will be done. Therefore, it is possible to prevent a shortage of the amount of heat supplied from the combustor 7 to the reformer 4. Therefore, in this fuel cell system 1, the combustion gas is satisfactorily generated by the reformer 4, so that the power generation efficiency can be improved.

(2) In the first embodiment, the plurality of guide plates 45 are the reformer 4 of the housing 32 in which the second off air supplied from the second off air supply port 42 to the second chamber 52 is mixed with the combustion gas. The second off-air is guided so as to circulate in the second chamber 52 along the side wall 34.
As a result, the combustion gas burned in the combustion region 53 does not flow directly to the combustion gas outlet 22, but circulates in the second chamber 52 along the wall 34 on the reformer 4 side of the housing 32. Therefore, the heat of the combustion gas can be efficiently and uniformly supplied from the combustor 7 to the reformer 4. Therefore, it is possible to prevent a shortage of the amount of heat supplied from the combustor 7 to the reformer 4 and reduce the temperature distribution of the reformer 4.
The second off-air supplied from the second off-air supply port 42 to the second chamber 52 does not contribute to the combustion of the first off-air discharged from the off-air discharge port 44 to the combustion region 53 and the off-fuel. .. Therefore, by using the second off-air for the flow of air guided by the plurality of guide plates 45, the heat of the combustion gas of the combustor 7 is modified without destabilizing the combustion of the combustion gas in the combustion region 53. It is possible to efficiently and uniformly supply the pawnbroker 4.

(3) In the first embodiment, the plurality of guide plates 45 are provided so as to be inclined in the circumferential direction with respect to the radial direction of the internal space 50. As a result, the plurality of guide plates 45 swirl the second off air blown from the second off air supply port 42 into the internal space 50 in the circumferential direction of the internal space 50, and the combustion gas is encapsulated along with the flow. It can be swiveled along the wall 34 on the reformer 4 side of the body 32. Therefore, the heat of the combustion gas can be efficiently and uniformly supplied to the reformer 4 provided on the outer side of the radial outer wall of the housing 32.

(Second Embodiment)
The second embodiment will be described. The second embodiment is a modification of the configuration of the structure provided in the combustor 7 with respect to the first embodiment, and the other configurations are the same as those of the first embodiment. Only the parts that differ from the above will be described.

As shown in FIG. 8, in the second embodiment, the wall member 47 as a structure is provided in the second chamber 52 of the internal space 50 of the combustor 7. The wall member 47 is formed in a tubular shape and is provided between the wall 34 on the reformer 4 side of the housing 32 and the combustion region 53. The material of the wall member 47 radiates more than the material of the wall 35 on the off-air passage 20 side of the housing 32 (that is, the wall 35 on the side opposite to the reformer 4 of the housing 32) or the material of the dividing member 33. It is made of high-rate material.

FIG. 9 is a simulation diagram showing the temperature distribution of the internal space 50 of the combustor 7.
As shown in FIG. 9, in the internal space 50 of the combustor 7, the wall member 47 is heated by the heat of the combustion gas burned in the combustion region 53. Then, the radiant heat radiated from the wall member 47 heats the wall 34 (particularly, the portion facing the wall member 47) on the reformer 4 side of the housing 32. Since the combustion gas burned in the combustion region 53 flows to the upper combustion gas outlet 22, the temperature of the space above the temperature of the space below is higher than the temperature of the space below in the vicinity of the wall 34 on the reformer 4 side of the housing 32. Is high.

FIG. 10 is a graph comparing the temperatures of the wall 34 on the reformer 4 side of the housing 32 of the combustor 7 with respect to the fuel cell system 1 according to the second embodiment and the fuel cell system of the first comparative example. is there.
In the fuel cell system of the first comparative example, the emissivity of the wall member 47 is the same as the emissivity of the wall 35 on the off-air passage 20 side of the housing 32 and is divided with respect to the configuration of the second embodiment described above. It uses the same material as the emissivity of the member 33.
In the graph of the first comparative example, A indicates the average temperature of the wall 34 on the reformer 4 side of the housing 32 of the combustor 7, B indicates the temperature of the upper portion of the wall 34, and C. Indicates the temperature of the lower part of the wall 34.
In the graph of the second embodiment, D indicates the average temperature of the wall 34 on the reformer 4 side of the housing 32 of the combustor 7, E indicates the temperature of the upper portion of the wall 34, and F. Indicates the temperature of the lower part of the wall 34.

As described above, in the second embodiment, the average temperature of the wall 34 on the reformer 4 side of the housing 32 of the combustor 7 is higher than that of the first comparative example, and the portion above the wall 34 is further increased. The temperature difference between the temperature of the lower part and the temperature of the lower part is small. From this, it can be said that the second embodiment can efficiently and uniformly supply the heat of the combustion gas from the combustor 7 to the reformer 4 as compared with the first comparative example.

The fuel cell system 1 of the second embodiment described above has the following effects.
In the second embodiment, the wall member 47 as a structure of the combustor 7 is provided between the wall 34 on the reformer 4 side of the housing 32 and the combustion region 53. The material of the wall member 47 is from the material of the wall 35 on the off-air passage 20 side of the housing 32 (that is, the wall 35 on the side opposite to the reformer 4 of the housing 32) or the material of the dividing member 33. Is also formed of high emissivity.
As a result, the wall member 47 is heated by the heat of the combustion gas, and the reformer 4 is heated by using the radiant heat of the wall member 47, so that the heat of the combustion gas burned by the combustor 7 is transferred to the reformer 4. It can be supplied efficiently and uniformly. Therefore, it is possible to prevent a shortage of the amount of heat supplied from the combustor 7 to the reformer 4 and reduce the temperature distribution of the reformer 4.
In addition, the fuel cell system 1 of the second embodiment can exhibit the same effects as those of the first embodiment.

(Third Embodiment)
The third embodiment will be described. The third embodiment is a modification of the configuration of the structure provided in the combustor 7 with respect to the first embodiment and the like, and the other configurations are the same as those of the first embodiment and the like. Only the part different from the embodiment and the like will be described.

As shown in FIG. 11, in the third embodiment, the dividing member 33 is composed of one member. The dividing member 33 has an annular plate 331 formed in an annular shape, and a tubular portion 332 connecting the outer outer edge of the annular plate 331 in the radial direction and the lower wall 36 of the housing 32. A plurality of off-air discharge ports 44 are provided in the vicinity of the lower wall 36 of the housing 32 in the tubular portion 332. The plurality of off-air outlets 44 are provided so as to be arranged in the circumferential direction. The plurality of off-air outlets 44 communicate the first chamber 51 and the second chamber 52.

As shown in FIG. 12, in the third embodiment, the structure for efficiently supplying the heat of the combustion gas burned in the combustor 7 to the reformer 4 is among the tubular portions 332 of the split member 33. It is composed of an end portion 333 on the off fuel supply port 43 side. The end portion 333 of the tubular portion 332 is provided so as to block a part of the off-fuel supply port 43 on the side opposite to the reformer 4. As a result, as shown by the arrows FF in FIGS. 11 and 12, the off-fuel blown out from the off-fuel supply port 43 to the second chamber 52 is on the lower side of the wall 34 on the reformer 4 side of the housing 32. It flows toward the part of. In other words, the lower portion of the wall 34 on the reformer 4 side of the housing 32 can be said to be the wall of the housing 32 corresponding to the portion of the reformer 4 far from the combustion gas outlet 22. Therefore, the structure of the third embodiment guides the off-fuel blown out from the off-fuel supply port 43 toward the wall of the housing 32 corresponding to the portion of the reformer 4 far from the combustion gas outlet 22. It is possible.

The fuel cell system 1 of the third embodiment described above has the following effects.
(1) In the third embodiment, the structure of the combustor 7 is a housing 32 in which the off fuel blown out from the off fuel supply port 43 corresponds to a portion of the reformer 4 far from the combustion gas outlet 22. It guides you toward the wall of.
As a result, the combustion gas burned by the off-fuel blown out from the off-fuel supply port 43 to the second chamber 52 flows toward the wall of the housing 32 corresponding to the portion of the reformer 4 far from the combustion gas outlet 22. After that, it flows to the combustion gas outlet 22. Therefore, the heat of the combustion gas can be efficiently and uniformly supplied from the portion of the reformer 4 far from the combustion gas outlet 22 to the portion near the combustion gas outlet 22.

(2) In the third embodiment, the structure of the combustor 7 is composed of the end portion 333 of the split member 33 on the off fuel supply port 43 side, and is the reformer 4 of the off fuel supply port 43. It is provided so as to block a part on the opposite side.
As a result, the structure can guide the off-fuel blown from the off-fuel supply port 43 to the second chamber 52 toward the reformer 4.
Further, the structure for efficiently supplying the heat of the combustion gas burned by the combustor 7 to the reformer 4 is formed by the end portion 333 of the split member 33 on the off fuel supply port 43 side. The manufacturing cost can be reduced without increasing the number of parts.

(Fourth and fifth embodiments)
The fuel cell system 1 described in the fourth and fifth embodiments recovers heat transferred from the combustor 7 to a portion other than the combustor 4 (particularly, the warm-up combustor 8 side) and moves to the combustor 7. It has a configuration for returning. Since other configurations are the same as those of the first embodiment and the like, only the parts different from the first embodiment and the like will be described.

(Fourth Embodiment)
As shown in FIG. 13, the fuel cell system 1 of the fourth embodiment recovers radiant heat radiated from the housing 32 of the combustor 7 to a portion other than the reformer 4, and enters the internal space 50 of the combustor 7. It has a heat recovery structure configured to return. Specifically, the heat recovery structure is a flow path wall 60 provided radially inside the combustor 7 so as to surround the outer walls of the warm-up combustor 8 and the warm-up combustion gas passage 30. The flow path wall 60 forms an air flow path 61 together with the outer wall of the warm-up combustor 8 and the warm-up combustion gas passage 30. The air flow path 61 constitutes a part of an air supply path 19 for supplying air from the outside air to the fuel cell stack 2.

As described above, the warm-up combustor 8 operates when the fuel cell system 1 is started, and stops operating when the fuel cell system 1 generates electricity. Therefore, it is conceivable that the temperature of the warm-up combustor 8 drops during power generation of the fuel cell system 1 and heat escapes from the combustor 7 to the warm-up combustor 8 side. Even in that case, in the fourth embodiment, the radiant heat radiated from the housing 32 of the combustor 7 to the warm-up combustor 8 side is recovered by the air flowing through the air flow path 61. Then, the air flowing through the air flow path 61 recovers the radiant heat and is then supplied to the fuel cell stack 2. After that, the air not consumed for power generation in the fuel cell stack 2 becomes off air and is supplied to the combustor 7 via the off air passage 20. As a result, the radiant heat radiated from the housing 32 of the combustor 7 to the warm-up combustor 8 side is recovered by the air flowing through the air flow path 61, passes through the fuel cell stack 2, and then passes through the off-air again. Is returned to the combustor 7.

FIG. 14 is a graph comparing the wall surface temperature of the bottom wall 81 of the warm-up combustor 8 with respect to the fuel cell system 1 according to the fourth embodiment and the fuel cell system of the second comparative example.
The fuel cell system of the second comparative example has a configuration that does not include the flow path wall 60 as a heat recovery structure, as opposed to the configuration of the fourth embodiment described above.

The solid line H in FIG. 14 shows the wall surface temperature of the warm-up combustor 8 included in the fuel cell system 1 of the fourth embodiment. On the other hand, the solid line I shows the wall surface temperature of the warm-up combustor 8 included in the fuel cell system of the second comparative example.
As shown in the graph of FIG. 14, in the fourth embodiment, the wall surface temperature of the warm-up combustor 8 is lower from the start-up to the power generation than in the second comparative example. As shown by hatching in the graph of FIG. 14, the temperature difference between the solid line H and the solid line I during power generation is the heat recovery structure of the radiant heat radiated from the housing 32 of the combustor 7 to the warm-up combustor 8 side. Corresponds to the amount of heat recovered by. As described above, the amount of heat is returned to the combustor 7 via the off-air.

The fuel cell system 1 of the fourth embodiment described above has the following effects.
(1) The fuel cell system 1 of the fourth embodiment is configured to recover radiant heat radiated from the housing 32 of the combustor 7 to a portion other than the reformer 4 and return it to the internal space 50 of the combustor 7. It has a heat recovery structure. As a result, the radiant heat radiated from the housing 32 of the combustor 7 to the portion other than the reformer 4 is recovered by the heat recovery structure and returned to the internal space 50 of the combustor 7 again, so that the combustor 7 reforms. The amount of heat supplied to the vessel 4 increases. Therefore, even if the fuel gas is repeatedly used for power generation in the fuel cell stack 2 and the off-fuel supplied to the combustor 7 is reduced, the shortage of the heat supply amount from the combustor 7 to the reformer 4 can be prevented. .. Therefore, in this fuel cell system 1, the combustion gas is satisfactorily generated by the reformer 4, so that the power generation efficiency can be improved.

(2) The heat recovery structure included in the fuel cell system 1 of the fourth embodiment is a flow path wall 60 provided radially inside the combustor 7 and surrounding the outer wall of the warm-up combustor 8. The flow path wall 60 forms an air flow path 61 together with the outer wall of the warm-up combustor 8.
As a result, the radiant heat radiated from the housing 32 of the combustor 7 to the warm-up combustor 8 side is recovered by the air flowing through the air flow path 61, and the heat is supplied to the combustor 7 again via the off-air. It is possible to do.
Further, since the flow path wall 60 as the heat recovery structure is provided so as to surround the outer wall of the warm-up combustor 8, the cross-sectional area of the air flow path 61 can be reduced and the air flow velocity can be increased. It is possible. As a result, the recovery rate of radiant heat radiated from the housing 32 of the combustor 7 to the warm-up combustor 8 side can be increased.

(Fifth Embodiment)
As shown in FIG. 15, the heat recovery structure included in the fuel cell system 1 of the fifth embodiment is an off-air flow path wall 62 provided so as to surround the radial inside of the housing 32 of the combustor 7. The off-air flow path wall 62 includes a tubular inner cylinder portion 63 and a flange portion 64 extending from the end of the inner cylinder portion 63 on the warm-up combustor 8 side to the housing 32 side of the combustor 7. And have. The flange portion 64 is connected to the housing 32 of the combustor 7. As a result, the off-air flow path wall 62 forms the off-air flow path 65 through which the off-air flows together with the housing 32 of the combustor 7. The off-air flow path 65 is a flow path that forms a part of the off-air passage 20, and is a flow path formed with a relatively small cross-sectional area of the flow path. The off air flowing through the off air flow path 65 is supplied to the internal space 50 of the combustor 7 from the first off air supply port 41 and the second off air supply port 42.

As described above, if the temperature of the warm-up combustor 8 drops during power generation of the fuel cell system 1, it is conceivable that heat escape occurs from the combustor 7 to the warm-up combustor 8 side. In that case, in the fifth embodiment, the radiant heat radiated from the housing 32 of the combustor 7 to the warm-up combustor 8 side is the off-air flowing through the off-air flow path 65 formed by the off-air flow path wall 62. Will be recovered by. Then, after recovering the radiant heat, the off-air is supplied to the internal space 50 of the combustor 7 from the first off-air supply port 41 and the second off-air supply port 42. As a result, the radiant heat radiated from the housing 32 of the combustor 7 to the warm-up combustor 8 side is recovered by the off-air flowing through the off-air flow path 65 and returned to the combustor 7 again.

As shown by the broken line 66 in FIG. 15, a tubular wall may be further provided between the off-air flow path wall 62 and the housing 32 of the combustor 7. As a result, by increasing the distance of the off-air flow path 65, the amount of radiant heat radiated from the housing 32 of the combustor 7 to the warm-up combustor 8 side can be increased.

FIG. 16 is a graph comparing the wall surface temperature on the off-air passage 20 side of the housing 32 of the combustor 7 with respect to the fuel cell system 1 according to the fifth embodiment and the fuel cell system of the third comparative example.
The fuel cell system of the third comparative example has a configuration that does not include the off-air flow path wall 62 as a heat recovery structure, as compared with the configuration of the fifth embodiment described above.

The solid line J in FIG. 16 shows the wall surface temperature of the wall 35 on the off-air passage 20 side of the housing 32 included in the combustor 7 of the fuel cell system 1 of the fifth embodiment. On the other hand, the solid line K indicates the wall surface temperature of the wall 35 on the off-air passage 20 side of the housing 32 of the combustor 7 of the fuel cell system of the third comparative example.

As shown in the graph of FIG. 16, in the fifth embodiment, the wall surface temperature of the wall 35 on the off-air passage 20 side of the housing 32 of the combustor 7 from the start to the power generation is different from that of the third comparative example. Is low. As shown by hatching in the graph of FIG. 16, the temperature difference between the solid line J and the solid line K during power generation is the heat recovery structure of the radiant heat radiated from the housing 32 of the combustor 7 to the warm-up combustor 8 side. Corresponds to the amount of heat recovered by. As described above, the amount of heat is returned to the combustor 7 again via the off-air flowing through the off-air flow path 65.

The fuel cell system 1 of the fifth embodiment described above has the following effects.
The heat recovery structure included in the fuel cell system 1 of the fifth embodiment is an off-air flow path wall 62 provided so as to surround the inside of the housing 32 of the combustor 7 in the radial direction. The off-air flow path wall 62 forms an off-air flow path 65 through which off-air flows together with the housing 32 of the combustor 7.
As a result, the radiant heat radiated from the housing 32 of the combustor 7 to the warm-up combustor 8 side can be recovered by the off-air flowing through the off-air flow path 65, and the heat can be supplied to the combustor 7 again. It is possible.
Further, since the off-air flow path wall 62 as the heat recovery structure surrounds the inside of the housing 32 of the combustor 7 in the radial direction, the cross-sectional area of the off-air flow path 65 is reduced to reduce the flow velocity of the off-air. It can be made faster. As a result, the recovery rate of radiant heat radiated from the housing 32 of the combustor 7 to the warm-up combustor 8 side can be increased.

As shown by the broken line 66 in FIG. 15, a tubular wall is further provided between the off-air flow path wall 62 and the housing 32 of the combustor 7, so that the housing 32 of the combustor 7 is warmed up. The recovery rate of radiant heat radiated to the machine combustor 8 side can be further increased.

(6th to 9th embodiments)
In the first to third embodiments described above, a structure including a structure for efficiently supplying the heat of the combustor 7 to the reformer 4 has been described. By the way, when heat is efficiently supplied from the internal space 50 of the combustor 7 to the reformer 4, the vicinity of the off-fuel supply port 43 located in the internal space 50 of the combustor 7 away from the reformer 4 The temperature of the combustor 7 may decrease, and the ignitability of the combustor 7 may decrease when the fuel cell system 1 is started.
Therefore, the sixth to ninth embodiments described below are provided with a configuration for stabilizing and improving the ignitability of the combustor 7 when the fuel cell system 1 is started. Since other configurations are the same as those of the first embodiment and the like, only the parts different from the first embodiment and the like will be described.

(Sixth Embodiment)
As shown in FIG. 17, the fuel cell system 1 of the sixth embodiment has a heat supply structure configured to supply a part of the heat of the combustion gas burned by the warm-up combustor 8 to the combustor 7. I have. Specifically, the heat supply structure is a heat conductive member 71 that connects the warm-up combustor 8 and the combustor 7. More specifically, the heat conductive member 71 connects the bottom wall 81 of the warm-up combustor 8 and the wall 35 on the off-air passage 20 side of the housing 32 of the combustor 7. The material of the heat conductive member 71 is formed of a material having a higher thermal conductivity than the material of the housing 32 of the combustor 7 or the material of the bottom wall 81 of the warm-up combustor 8. Further, the heat conductive member 71 is considered to have a relatively small physique, and is provided at at least one place.

FIG. 18 is a graph comparing the temperatures of the internal space 50 of the combustor 7 with respect to the fuel cell system 1 according to the sixth embodiment and the fuel cell system of the fourth comparative example.
The fuel cell system of the fourth comparative example has a configuration that does not include the heat conductive member 71 as a heat supply structure, as opposed to the configuration of the sixth embodiment described above.

The solid line L in FIG. 18 shows the temperature of the internal space 50 of the combustor 7 included in the fuel cell system 1 of the sixth embodiment. On the other hand, the solid line M indicates the temperature of the internal space 50 of the combustor 7 included in the fuel cell system of the fourth comparative example.
As shown in the graph of FIG. 18, in the sixth embodiment, the temperature of the internal space 50 of the combustor 7 is shorter than that from the start of the fuel cell system 1, and the off-fuel is removed as compared with the fourth comparative example. It is higher than the self-igniting temperature. Therefore, in the sixth embodiment, the combustion of the combustor 7 can be started in a short time from the start of the fuel cell system 1 as compared with the fourth comparative example.

The fuel cell system 1 of the sixth embodiment described above has the following effects.
(1) The fuel cell system 1 of the sixth embodiment includes a heat supply structure that supplies a part of the heat of the combustion gas burned by the warm-up combustor 8 to the combustor 7. As a result, the temperature of the internal space 50 of the combustor 7 rises in a short time when the fuel cell system 1 is started. Therefore, the combustor 7 can be stably ignited when the fuel cell system 1 is started.

In the heat supply structure, the temperature of a part of the internal space 50 of the combustor 7 is raised to create a fire in the combustor 7, and the fire is transferred from the fire to transfer the entire combustion region 53 of the combustor 7. It is possible to burn with. Therefore, it is possible to reduce the size of the heat supply structure and to reduce the number to at least one. Therefore, when the warm-up combustor 8 is stopped during power generation, it is possible to prevent heat from escaping from the combustor 7 to the warm-up combustor 8 via the heat supply structure.

(2) In the sixth embodiment, the heat supply structure is composed of a heat conductive member 71 that connects the combustor 7 and the warm-up combustor 8. The material of the heat conductive member 71 is formed of a material having a higher thermal conductivity than the material of the housing 32 of the combustor 7 or the material of the outer wall of the warm-up combustor 8.
As a result, when the fuel cell system 1 is started, the heat of the combustion gas burned in the warm-up combustor 8 is transferred to the combustor 7 via the heat conductive member 71, so that the temperature of the internal space 50 of the combustor 7 rises. It rises in a short time. Therefore, the combustor 7 can be stably ignited when the fuel cell system 1 is started.

(7th Embodiment)
As shown in FIG. 19, the heat supply structure included in the fuel cell system 1 of the seventh embodiment communicates the warm-up combustion chamber 29 inside the warm-up combustor 8 with the first chamber 51 of the combustor 7. It is a combustion gas supply path 72. The combustion gas supply path 72 is formed of a pipe or the like, and the combustion gas burned in the warm-up combustion chamber 29 of the warm-up combustor 8 can be supplied to the first chamber 51 of the combustor 7. Further, the combustion gas supply path 72 is considered to have a relatively small physique, and is provided at at least one place. As a result, when the fuel cell system 1 is started, a part of the combustion gas burned in the warm-up combustion chamber 29 of the warm-up combustor 8 passes through the combustion gas supply path 72 to the first chamber of the combustor 7. It is supplied to 51. Therefore, since the temperature of the first off-air rises, the combustor 7 can be stably ignited.

FIG. 20 is a simulation diagram showing the temperature distribution of the internal space 50 of the combustor 7.
As shown in FIG. 20, in the internal space 50 of the combustor 7, the temperature of the first chamber 51 is higher than the temperature of the second chamber 52. The off-air in the first chamber 51 is discharged from the off-air discharge port 44 to the combustion region 53, which contributes to combustion.

The fuel cell system 1 of the seventh embodiment described above has the following effects.
In the seventh embodiment, the combustion gas supply path 72 as a heat supply structure supplies a part of the combustion gas burned by the warm-up combustor 8 to the first chamber 51 of the combustor 7. As a result, when the fuel cell system 1 is started, a part of the combustion gas burned in the warm-up combustor 8 is supplied to the first chamber 51 of the combustor 7 via the combustion gas supply path 72. Therefore, the temperature of the first off-air supplied from the first chamber 51 to the combustion region 53 becomes high, so that the combustor 7 can be ignited stably.

The combustion gas supply path 72 creates a fire in the combustion region 53 of the combustor 7 by raising the temperature of a part of the first chamber 51 of the combustor 7, and transfers the fire from the fire to the combustor. It is possible to burn the entire combustion region 53 of 7. Therefore, it is possible to reduce the size of the combustion gas supply path 72 and to reduce the number of the combustion gas supply path 72 to at least one. Therefore, when the warm-up combustor 8 is stopped during power generation, it is possible to prevent heat from escaping from the combustor 7 to the warm-up combustor 8 via the combustion gas supply path 72. ..

(8th Embodiment)
As shown in FIGS. 21 and 22, the heat supply structure included in the fuel cell system 1 of the eighth embodiment is a predetermined off-fuel supply port 431 among a plurality of off-fuel supply ports 43. The predetermined off-fuel supply port 431 is a wall on the warm-up combustor 8 side of the housing 32 of the housing 7 (that is, the off-air passage 20 of the housing 32) as compared with the other off-fuel supply ports 43. It is provided at a position close to the side wall 35).

Then, as shown by an arrow N in FIG. 21, the predetermined off-fuel supply port 431 is a wall 35 on the warm-up combustor 8 side of the housing 32 of the housing 7 (that is, off air of the housing 32). It is configured to blow off fuel toward the wall 35) on the side of the passage 20. In FIG. 21, the direction in which the off-fuel is blown out from the predetermined off-fuel supply port 431 is indicated by an arrow N. When the fuel cell system 1 is started, the wall 35 on the warm-up combustor 8 side of the housing 32 of the combustor 7 (that is, the housing 32 is turned off) due to radiant heat radiated from the warm-up combustor 8 or the like. The temperature of the wall 35) on the air passage 20 side becomes high. Therefore, it is possible to create a fire in the combustor 7 by blowing off fuel from a predetermined off-fuel supply port 431 toward the wall 35. In FIG. 21, the fire type is schematically shown and the reference numeral FP is attached.

The combustion gas that has become the source of the fire moves from the first chamber 51 to the combustion region 53 of the second chamber 52 through the off-air discharge port 44. Therefore, it is possible to transfer the fire to the other off-fuel blown out from the off-fuel supply port 43 and burn the entire combustion region 53 of the combustor 7. In FIG. 21, the flame transferred from the fire type is schematically shown and is designated by the symbol FL.

In the eighth embodiment described above, by configuring the predetermined off-fuel supply port 431 of the combustor 7 as described above, the combustor 7 can be stably ignited when the fuel cell system 1 is started. ..

(9th Embodiment)
As shown in FIGS. 23 and 24, in the fuel cell system 1 of the ninth embodiment, the oxidation catalyst 73 is installed in the vicinity of some of the off-fuel supply ports 43 among the plurality of off-fuel supply ports 43. The oxidation catalyst 73 can ignite the off-fuel blown out from the off-fuel supply port 43 in the vicinity where the oxidation catalyst 73 is provided at a relatively low temperature, and serves as an ignition source for the off-fuel. is there. That is, it is possible to burn the entire combustion region 53 of the combustor 7 by using the combustion with the oxidation catalyst 73 as the ignition source as the ignition source and transferring the combustion to the off-fuel blown out from the other off-fuel supply port 43. Is. Therefore, the fuel cell system 1 can stably ignite the combustor 7 at the time of starting.

The oxidation catalyst 74 provided in the middle of the combustion gas passage 23 communicating with the combustion gas outlet 22 of the combustor 7 oxidizes off fuel such as carbon monoxide unburned in the combustor 7.

FIG. 25 is a graph comparing the relationship between the off-fuel temperature and the combustion rate of the fuel cell system 1 according to the ninth embodiment and the fuel cell system of the fifth comparative example.
The fuel cell system of the fifth comparative example has a configuration in which the oxidation catalyst 73 is not installed in the vicinity of the off-fuel supply port 43, as compared with the configuration of the ninth embodiment described above.

As shown by the solid line P in FIG. 25, in the fifth comparative example, the combustion rate increases when the temperature of the off-fuel supplied to the combustor 7 becomes equal to or higher than a predetermined temperature. On the other hand, as shown by the solid line Q in FIG. 25, in the ninth embodiment, the combustion rate increases when the temperature of the off-fuel supplied to the combustor 7 is lower than that in the fifth comparative example. Therefore, in the fuel cell system 1 of the ninth embodiment, it is possible to burn off fuel from a state where the temperature of the combustor 7 is relatively low at the time of startup, so that the combustor 7 can be ignited stably. ..

(Other embodiments)
The present invention is not limited to the above-described embodiment, and can be appropriately modified within the scope of the claims. Further, the above-described embodiments are not unrelated to each other, and can be appropriately combined unless the combination is clearly impossible. Further, in each of the above embodiments, it goes without saying that the elements constituting the embodiment are not necessarily essential except when it is clearly stated that they are essential and when they are clearly considered to be essential in principle. No. Further, in each of the above embodiments, when numerical values such as the number, numerical values, amounts, and ranges of the constituent elements of the embodiment are mentioned, when it is clearly stated that they are particularly essential, and in principle, the number is clearly limited to a specific number. It is not limited to the specific number except when it is done. Further, in each of the above embodiments, when referring to the shape, positional relationship, etc. of a component or the like, the shape, unless otherwise specified or limited in principle to a specific shape, positional relationship, etc. It is not limited to the positional relationship.

(1) In each of the above embodiments, the fuel cell stack 2 included in the fuel cell system 1 has been described as being composed of a solid oxide fuel cell (SOFC), but the present invention is not limited to this. .. As the fuel cell stack 2, various fuel cells such as a polymer electrolyte fuel cell (PEFC) can be adopted.

(2) In each of the above embodiments, the combustor 7 provided in the fuel cell system 1 has been described as being formed in an annular shape, but the present invention is not limited to this. As the shape of the combustor 7, various shapes such as a rectangular parallelepiped and a cube can be adopted.

(3) In each of the above embodiments, the fuel cell system 1 is described as being provided with an ejector 3 to recycle off-fuel for repeated use, but the present invention is not limited to this. The present invention can also be applied to a fuel cell system 1 that does not include an ejector 3.

(4) In the first embodiment, the guide plate 45 as a structure has been described as being provided on the dividing member 33, but the present invention is not limited to this. The guide plate 45 may be provided so as to project radially outward from the wall 35 on the off-air passage 20 side of the housing 32, or the upper wall 37 of the housing 32 to the lower wall 36 of the housing 32. It may be provided so as to protrude to the side.

(5) In the second embodiment, the wall member 47 as a structure has been described as being provided in a tubular shape, but the present invention is not limited to this, and the shape thereof is, for example, intermittently in the circumferential direction of the internal space 50. It may be provided.

(6) In the third embodiment, the structure that closes a part of the off fuel supply port 43 is composed of the end portion 333 of the tubular portion 332 of the split member 33 on the off fuel supply port 43 side. I explained, but it is not limited to this. The structure that closes a part of the off fuel supply port 43 may be formed of a member different from the split member 33. Alternatively, by configuring the hole of the off-fuel supply port 43 itself to face the wall 34 side of the reformer 4 side of the housing 32, the off-fuel blown out from the off-fuel supply port 43 is the wall 34. It may flow toward the lower part of the.

(7) In the sixth and seventh embodiments, the heat conductive member 71 and the combustion gas supply path 72 as the heat supply structure for supplying heat from the warm-up combustor 8 to the combustor 7 are located at least in one place. Although it has been explained as being provided, it is not limited to this. The heat conductive member 71 and the combustion gas supply path 72 may be provided at a plurality of locations. Further, the position of the housing 32 of the combustor 7 to which the heat conductive member 71 is connected is not limited. Further, the location of the internal space 50 of the combustor 7 through which the combustion gas supply path 72 communicates is not limited to the first chamber 51, but may be, for example, the second chamber 52.

(8) In the eighth embodiment, the predetermined off-fuel supply port 431 out of the plurality of off-fuel supply ports 43 has been described as at least one, but the number may be plural.

(9) In the ninth embodiment, the number of oxidation catalysts 73 has been described as at least one, but the number may be plural.

(Summary)
According to the first aspect shown in part or all of the above embodiments, the fuel cell system comprises a fuel cell stack, a reformer and a combustor. The fuel cell stack generates electricity by reacting the fuel gas with the oxidant gas. The reformer reforms the source fuel into fuel gas that supplies the fuel cell stack. The combustor burns off-fuel containing fuel gas not consumed in the fuel cell stack and off-air containing oxidant gas not consumed in the fuel cell stack.
The combustor has a housing, a split member, a first off-air supply port, a second off-air supply port, an off-fuel supply port, an off-air discharge port, and a structure. The housing forms the internal space of the combustor. The dividing member divides the internal space of the combustor into a first chamber and a second chamber. The first off-air supply port supplies off-air to the first chamber. The second off-air supply port supplies off-air to the second chamber. The off-fuel supply port supplies off-fuel to the second chamber. The off-air outlet discharges off-air from the first chamber to the combustion region where the off-fuel burns in the second chamber. The structure is provided in the internal space of the combustor, and is configured to supply the heat of the combustion gas burned by the off-fuel and the off-air to the reformer.
According to this, even if the fuel gas is used for power generation in the fuel cell stack and the off-fuel supplied to the combustor is reduced, the heat of the combustion gas is efficiently supplied from the combustor to the reformer. , The shortage of heat supply from the combustor to the reformer can be prevented. Therefore, in this fuel cell system, the combustion gas is satisfactorily generated by the reformer, so that the power generation efficiency can be improved.

According to the second aspect, the structure is a guide plate that guides the off-air supplied from the second off-air supply port to the second chamber. The off-air supplied from the second off-air supply port to the second chamber is guided by the guide plate and circulates together with the combustion gas in the second chamber along the wall on the reformer side of the housing.
According to this, the combustion gas burned in the combustion region does not flow directly to the combustion gas outlet, but circulates in the second chamber along the wall on the reformer side of the housing. Therefore, it is possible to efficiently and uniformly supply the heat of the combustion gas from the combustor to the reformer. Therefore, it is possible to prevent a shortage of the heat supply amount from the combustor to the reformer and reduce the temperature distribution of the reformer.
The second off-air flowing out from the second off-air supply port to the second chamber does not contribute to the combustion of the first off-air discharged from the off-air discharge port and the off-fuel. Therefore, by using the second off-air for the air flow guided by the guide plate, the heat of the combustion gas of the combustor can be efficiently transferred to the reformer without destabilizing the combustion of the combustion gas in the combustion region. Moreover, it is possible to supply uniformly.

According to the third viewpoint, the internal space of the combustor is formed in an annular shape. A second off-air supply port is provided on the radial inner wall of the housing, and a reformer is provided on the outer side of the radial outer wall of the housing. The guide plate is provided so as to be inclined in the circumferential direction with respect to the radial direction of the internal space.
According to this, the guide plate swirls the second off air blown out from the second off air supply port into the internal space in the circumferential direction of the internal space, and reforms the combustion gas with the flow of the second off air. It can be swiveled along the wall on the vessel side. Therefore, the heat of the combustion gas can be efficiently and uniformly supplied to the reformer provided on the outer side of the radial outer wall of the housing.

According to the fourth aspect, the structure is a wall member provided between the wall on the reformer side of the housing and the combustion region. The material of the wall member is formed of a material having a higher emissivity than the material of the wall on the opposite side of the reformer of the housing or the material of the dividing member.
According to this, the wall member is heated by the heat of the combustion gas, and the reformer is heated by using the radiant heat of the wall member, so that the heat of the combustion gas burned by the combustor is efficiently transferred to the reformer. Can be supplied. Furthermore, the temperature distribution of the reformer can be made uniform.

According to the fifth aspect, the second chamber of the combustor is provided with a combustion gas outlet for discharging the combustion gas. Then, the structure guides the off-fuel blown out from the off-fuel supply port to the second chamber toward the wall of the housing corresponding to the portion of the reformer far from the combustion gas outlet.
According to this, the combustion gas burned by the off-fuel blown out from the off-fuel supply port to the second chamber flowed toward the inner wall surface of the housing corresponding to the portion of the reformer far from the combustion gas discharge port. After that, it flows to the combustion gas outlet. Therefore, the heat of the combustion gas can be efficiently and uniformly supplied from the portion of the reformer far from the combustion gas discharge port to the portion close to the combustion gas discharge port.

According to the sixth aspect, the structure is composed of the end portion of the split member on the off fuel supply port side, and is provided so as to block a part of the off fuel supply port on the side opposite to the reformer. ing.
According to this, the structure can guide the off-fuel blown out from the off-fuel supply port to the second chamber toward the reformer side.
Further, by forming the structure by the end portion of the split member on the off-fuel supply port side, it is possible to reduce the manufacturing cost without increasing the number of parts.

According to a seventh aspect, the fuel cell system further comprises a warm-up combustor and a heat recovery structure. The warm-up combustor burns the source fuel and air by igniting the spark plug. The heat recovery structure is configured to recover the radiant heat radiated from the housing of the combustor to the parts other than the reformer and return it to the internal space of the combustor.
According to this, the radiant heat radiated from the housing of the combustor to the part other than the reformer is recovered by the heat recovery structure and returned to the internal space of the combustor, so that it is supplied from the combustor to the reformer. Increases the amount of heat generated. Therefore, even if the off-fuel supplied to the combustor is reduced when the fuel gas is used for power generation in the fuel cell stack, the shortage of the heat supply amount from the combustor to the reformer can be prevented. Therefore, in this fuel cell system, the combustion gas is satisfactorily generated by the reformer, so that the power generation efficiency can be improved.

According to the eighth aspect, the fuel cell system further comprises a warm-up combustor and a heat supply structure. The warm-up combustor burns the source fuel and air by igniting the spark plug. The heat supply structure supplies a part of the heat of the combustion gas burned by the warm-up combustor to the combustor.
According to this, the temperature of the internal space of the combustor rises in a short time when the fuel cell system is started. Therefore, the combustor can be stably ignited when the fuel cell system is started.
In the heat supply structure, by raising the temperature of a part of the internal space of the combustor, a fire type is created in the combustor, and by transferring the fire from the fire type, it is possible to burn the entire combustion region of the combustor. It is possible. Therefore, it is possible to reduce the size of the heat supply structure and to reduce the number to at least one. Therefore, when the warm-up combustor is stopped during power generation, it is possible to prevent heat from escaping from the combustor to the warm-up combustor via the heat supply structure.

According to the ninth aspect, the combustor further has an oxidation catalyst provided in the vicinity of some of the off-fuel supply ports among the plurality of off-fuel supply ports.
According to this, it is possible to ignite the off-fuel blown out from the off-fuel supply port in the vicinity where the oxidation catalyst is provided at a relatively low temperature to produce a fire. By transferring the fire to the off-fuel blown out from the other off-fuel supply port, it is possible to burn the entire combustion region of the combustor. Therefore, this fuel cell system can stably ignite the combustor at startup.

According to a tenth aspect, the fuel cell system comprises a fuel cell stack, a reformer, a warm-up combustor, a combustor, and a heat recovery structure. The fuel cell stack generates electricity by reacting the fuel gas with the oxidant gas. The reformer reforms the source fuel into fuel gas that supplies the fuel cell stack. The warm-up combustor burns the source fuel and air by igniting the spark plug. The combustor burns off-fuel containing fuel gas not consumed in the fuel cell stack and off-air containing oxidant gas not consumed in the fuel cell stack.
The combustor has a housing, a split member, a first off-air supply port, a second off-air supply port, an off-fuel supply port, and an off-air discharge port. The housing forms the internal space of the combustor. The dividing member divides the internal space of the combustor into a first chamber and a second chamber. The first off-air supply port supplies off-air to the first chamber. The second off-air supply port supplies off-air to the second chamber. The off-fuel supply port supplies off-fuel to the second chamber. The off-air outlet discharges off-air from the first chamber to the combustion region where the off-fuel burns in the second chamber.
The heat recovery structure is configured to recover the radiant heat radiated from the housing of the combustor to a portion other than the reformer and return it to the internal space of the combustor.
According to this, the ninth viewpoint can also exert the same action and effect as the seventh viewpoint.

According to the eleventh aspect, the combustor is formed in an annular shape, and the warm-up combustor is provided inside the combustor in the radial direction. The heat recovery structure is a flow path wall provided radially inside the combustor and surrounding the outer wall of the warm-up combustor. The flow path wall forms an air flow path together with the outer wall of the warm-up combustor. The fuel cell system is configured such that the air flowing through the air flow path passes through the fuel cell stack, becomes off-air, and is supplied to the internal space of the combustor.
According to this, the radiant heat radiated from the combustor housing to the warm-up combustor side can be recovered by the air flowing through the air flow path, and the heat can be supplied to the combustor again via the off-air. It is possible.
Further, since the flow path wall as the heat recovery structure is provided so as to surround the outer wall of the warm-up combustor, it is possible to reduce the cross-sectional area of the air flow path and increase the air flow velocity. .. As a result, the recovery rate of radiant heat radiated from the combustor housing to the warm-up combustor side can be increased.

According to the twelfth aspect, the combustor is formed in an annular shape, and the warm-up combustor is provided inside the combustor in the radial direction. The heat recovery structure is an off-air flow path wall provided so as to surround the inside in the radial direction of the housing of the combustor. The off-air flow path wall forms an off-air flow path through which off-air flows together with the housing of the combustor. The fuel cell system is configured so that the off-air flowing through the off-air flow path is supplied to the internal space of the combustor from the first off-air supply port and the second off-air supply port.
According to this, the radiant heat radiated from the combustor housing to the warm-up combustor side can be recovered by the off-air flowing through the off-air flow path, and the heat can be supplied to the combustor again. ..
Further, since the off-air flow path wall as the heat recovery structure is configured to surround the inside of the combustor housing in the radial direction, the cross-sectional area of the off-air flow path can be reduced and the off-air flow velocity can be increased. It is possible. As a result, the recovery rate of radiant heat radiated from the combustor housing to the warm-up combustor side can be increased.

According to a thirteenth aspect, the fuel cell system comprises a fuel cell stack, a reformer, a warm-up combustor, a combustor, and a heat supply structure. The fuel cell stack generates electricity by reacting the fuel gas with the oxidant gas. The reformer reforms the source fuel into fuel gas that supplies the fuel cell stack. The warm-up combustor burns the source fuel and air by igniting the spark plug. The combustor burns off-fuel containing fuel gas not consumed in the fuel cell stack and off-air containing oxidant gas not consumed in the fuel cell stack.
The combustor has a housing, a split member, a first off-air supply port, a second off-air supply port, an off-fuel supply port, and an off-air discharge port. The housing forms the internal space of the combustor. The dividing member divides the internal space of the combustor into a first chamber and a second chamber. The first off-air supply port supplies off-air to the first chamber. The second off-air supply port supplies off-air to the second chamber. The off-fuel supply port supplies off-fuel to the second chamber. The off-air outlet discharges off-air from the first chamber to the combustion region where the off-fuel burns in the second chamber.
Then, the heat supply structure supplies a part of the heat of the combustion gas burned by the warm-up combustor to the combustor.
According to this, the twelfth viewpoint can also exert the same action and effect as the eighth viewpoint.

According to the fourteenth aspect, the heat supply structure is a heat conductive member that connects the combustor and the warm-up combustor. The material of the heat conductive member is formed of a material having a higher thermal conductivity than the material of the housing of the combustor or the material of the outer wall of the combustor for warming up.
According to this, when the fuel cell system is started, the heat of the combustion gas burned in the warm-up combustor is transferred to the combustor via the heat conductive member, so that the temperature of the internal space of the combustor rises in a short time. To do. Therefore, the combustor can be stably ignited when the fuel cell system is started.

According to the fifteenth viewpoint, the heat supply structure is a combustion gas supply path for supplying a part of the combustion gas burned in the warm-up combustor to the first chamber of the combustor.
According to this, when the fuel cell system is started, a part of the combustion gas burned in the warm-up combustor is supplied to the first chamber of the combustor via the combustion gas supply path. Therefore, the temperature of the first off-air supplied from the first chamber to the combustion region becomes high, so that the combustor can be stably ignited.

According to the sixteenth aspect, the heat supply structure is a predetermined off-fuel supply port among the plurality of off-fuel supply ports. The predetermined off-fuel supply port is provided at a position closer to the wall on the warm-up combustor side of the housing of the combustor than the other off-fuel supply ports, and the housing of the combustor has. It is configured to blow off fuel toward the wall on the warm-up combustor side.
According to this, when the fuel cell system is started, the temperature of the wall on the warm-up combustor side of the housing of the combustor becomes high due to the radiant heat radiated from the warm-up combustor. Therefore, it is possible to create a fire in the combustor by blowing off fuel from a predetermined off-fuel supply port toward the inner wall surface. By transferring the fire to the off-fuel blown out from the other off-fuel supply port, it is possible to burn the entire combustion region of the combustor. Therefore, the combustor can be ignited stably.

According to a seventeenth aspect, the fuel cell system comprises a fuel cell stack, a reformer and a combustor. The fuel cell stack generates electricity by reacting the fuel gas with the oxidant gas. The reformer reforms the source fuel into fuel gas that supplies the fuel cell stack. The combustor burns off-fuel containing fuel gas not consumed in the fuel cell stack and off-air containing oxidant gas not consumed in the fuel cell stack.
The combustor has a housing, a split member, a first off-air supply port, a second off-air supply port, an off-fuel supply port, an off-air discharge port, and an oxidation catalyst. The housing forms the internal space of the combustor. The dividing member divides the internal space of the combustor into a first chamber and a second chamber. The first off-air supply port supplies off-air to the first chamber. The second off-air supply port supplies off-air to the second chamber. The off-fuel supply port supplies off-fuel to the second chamber. The off-air outlet discharges off-air from the first chamber to the combustion region where the off-fuel burns in the second chamber. The oxidation catalyst is provided in the vicinity of some of the off-fuel supply ports of the plurality of off-fuel supply ports.
According to this, the 17th viewpoint can also exert the same action and effect as the 9th viewpoint.

1: Fuel cell system, 2: Fuel cell stack,
4: Reformer, 7: Combustor,
32: Housing, 33: Dividing member,
41: 1st off air supply port, 42: 2nd off air supply port,
43: Off fuel supply port, 44: Off air outlet,
45, 47, 333: structure, 50: internal space,
51: Room 1, 52: Room 2,
53: Combustion area

Claims (17)

A fuel cell stack (2) that generates electricity by reacting fuel gas and oxidant gas, and
A reformer (4) that reforms the source fuel into the fuel gas supplied to the fuel cell stack, and
In a fuel cell system comprising an off-fuel containing fuel gas not consumed in the fuel cell stack and a combustor (7) for burning off-air containing oxidant gas not consumed in the fuel cell stack.
The combustor
A housing (32) forming the internal space (50) of the combustor and
A dividing member (33) that divides the internal space of the combustor into a first chamber (51) and a second chamber (52), and
A first off-air supply port (41) for supplying off-air to the first chamber,
A second off-air supply port (42) for supplying off-air to the second chamber,
An off-fuel supply port (43) for supplying off-fuel to the second chamber,
An off-air discharge port (44) for discharging off-air from the first chamber to a combustion region (53) where off-fuel burns in the second chamber,
It has a structure (45, 47, 333) provided in the internal space of the combustor and configured to supply heat of combustion gas burned by off-fuel and off-air to the reformer. The fuel cell system. In the structure, the off air supplied from the second off air supply port to the second chamber circulates together with the combustion gas in the second chamber along the wall (34) on the reformer side of the housing. The fuel cell system according to claim 1, wherein the guide plate (45) guides the off-air supplied from the second off-air supply port to the second chamber. The internal space of the combustor is formed in an annular shape.
The second off-air supply port is provided on the radial inner wall of the housing, and the reformer is provided on the outer side of the radial outer wall of the housing.
The fuel cell system according to claim 2, wherein the guide plate is provided so as to be inclined in the circumferential direction with respect to the radial direction of the internal space. The structure is a wall member (47) provided between the wall on the reformer side of the housing and the combustion region.
The material of the wall member according to claim 1, wherein the material of the wall member is formed of a material of the wall (35) opposite to the reformer of the housing or a material having a higher emissivity than the material of the dividing member. Fuel cell system. A combustion gas outlet (22) for discharging combustion gas is provided in the second chamber of the combustor.
The structure (333) guides the off-fuel blown from the off-fuel supply port to the second chamber toward the wall of the housing corresponding to the portion of the reformer far from the combustion gas outlet. The fuel cell system according to claim 1. The structure is composed of an end portion (333) of the split member on the off-fuel supply port side, and is provided so as to close a part of the off-fuel supply port on the side opposite to the reformer. The fuel cell system according to claim 5. A warm-up combustor (8) that burns the source fuel and air by ignition of the spark plug (24), and
Further, a heat recovery structure (60, 62) configured to recover radiant heat radiated from the housing of the combustor to a portion other than the reformer and return it to the internal space of the combustor. The fuel cell system according to any one of claims 1 to 6, further comprising. A warm-up combustor (8) that burns the source fuel and air by ignition of the spark plug (24), and
One of claims 1 to 7, further comprising a heat supply structure (71, 72, 431) for supplying a part of the heat of the combustion gas burned by the warm-up combustor to the combustor. The described fuel cell system. The combustor is any one of claims 1 to 8, further comprising an oxidation catalyst (73) provided in the vicinity of some of the off-fuel supply ports among the plurality of off-fuel supply ports. The fuel cell system described in. A fuel cell stack (2) that generates electricity by reacting fuel gas and oxidant gas, and
A reformer (4) that reforms the source fuel into the fuel gas supplied to the fuel cell stack, and
A warm-up combustor (8) that burns the source fuel and air by ignition of the spark plug (24), and
In a fuel cell system comprising an off-fuel containing fuel gas not consumed in the fuel cell stack and a combustor (7) for burning off-air containing oxidant gas not consumed in the fuel cell stack.
The combustor
A housing (32) forming the internal space (50) of the combustor and
A dividing member (33) that divides the internal space of the combustor into a first chamber (51) and a second chamber (52), and
A first off-air supply port (41) for supplying off-air to the first chamber,
A second off-air supply port (42) for supplying off-air to the second chamber,
An off-fuel supply port (43) for supplying off-fuel to the second chamber,
An off-air discharge port (44) for discharging off-air from the first chamber is provided in a combustion region (53) where off-fuel is burned in the second chamber.
A fuel cell further comprising a heat recovery structure (60, 62) configured to recover radiant heat radiated from the housing of the combustor to a portion other than the reformer and return it to the internal space of the combustor. system. The combustor is formed in an annular shape
The warm-up combustor is provided inside the combustor in the radial direction.
The heat recovery structure is provided so as to surround the outer wall of the warm-up combustor on the radial inside of the combustor, and forms an air flow path together with the outer wall of the warm-up combustor (60). ) And
The fuel cell system according to claim 10, wherein the air flowing through the air flow path is configured to be supplied to the internal space of the combustor as off-air via the fuel cell stack. The combustor is formed in an annular shape
The warm-up combustor is provided inside the combustor in the radial direction.
The heat recovery structure is provided so as to surround the radial inside of the housing of the combustor, and forms an off-air flow path through which off-air flows together with the housing of the combustor (62). ) And
The tenth aspect of the present invention, wherein the off-air flowing through the off-air flow path is configured to be supplied to the internal space of the combustor from the first off-air supply port and the second off-air supply port. Fuel cell system. A fuel cell stack (2) that generates electricity by reacting fuel gas and oxidant gas, and
A reformer (4) that reforms the source fuel into the fuel gas supplied to the fuel cell stack, and
A warm-up combustor (8) that burns the source fuel and air by ignition of the spark plug (24), and
In a fuel cell system comprising an off-fuel containing fuel gas not consumed in the fuel cell stack and a combustor (7) for burning off-air containing oxidant gas not consumed in the fuel cell stack.
The combustor
A housing (32) forming the internal space (50) of the combustor and
A dividing member (33) that divides the internal space of the combustor into a first chamber (51) and a second chamber (52), and
A first off-air supply port (41) for supplying off-air to the first chamber,
A second off-air supply port (42) for supplying off-air to the second chamber,
An off-fuel supply port (43) for supplying off-fuel to the second chamber,
An off-air discharge port (44) for discharging off-air from the first chamber is provided in a combustion region (53) where off-fuel is burned in the second chamber.
A fuel cell system further comprising a heat supply structure (71, 72, 431) for supplying a part of the heat of the combustion gas burned by the warm-up combustor to the combustor. The heat supply structure is a heat conductive member (71) that connects the combustor and the warm-up combustor.
The fuel cell according to claim 13, wherein the material of the heat conductive member is formed of a material having a higher thermal conductivity than the material of the housing of the combustor or the material of the outer wall of the warm-up combustor. system. The fuel according to claim 13, wherein the heat supply structure is a combustion gas supply path (72) for supplying a part of the combustion gas burned by the warm-up combustor to the first chamber of the combustor. Battery system. The heat supply structure is a predetermined off-fuel supply port (431) among the plurality of off-fuel supply ports.
The predetermined off-fuel supply port is provided at a position closer to the wall (35) on the warm-up combustor side of the housing of the combustor than the other off-fuel supply ports. The fuel cell system according to claim 13, wherein off-fuel is blown out toward the wall of the housing of the combustor on the side of the warm-up combustor. A fuel cell stack (2) that generates electricity by reacting fuel gas and oxidant gas, and
A reformer (4) that reforms the source fuel into the fuel gas supplied to the fuel cell stack, and
In a fuel cell system comprising an off-fuel containing fuel gas not consumed in the fuel cell stack and a combustor (7) for burning off-air containing oxidant gas not consumed in the fuel cell stack.
The combustor
A housing (32) forming the internal space (50) of the combustor and
A dividing member (33) that divides the internal space of the combustor into a first chamber (51) and a second chamber (52), and
A first off-air supply port (41) for supplying off-air to the first chamber,
A second off-air supply port (42) for supplying off-air to the second chamber,
A plurality of off-fuel supply ports (43) for supplying off-fuel to the second chamber, and
An off-air discharge port (44) for discharging off-air from the first chamber to a combustion region (53) where off-fuel burns in the second chamber,
A fuel cell system having an oxidation catalyst (73) provided in the vicinity of some of the off-fuel supply ports among the plurality of off-fuel supply ports.

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