JP7126395B2 - fuel cell module - Google Patents

Description

The present invention relates to fuel cell modules.

Conventionally, a solid oxide fuel cell stack, a reformer that reforms the raw fuel gas to produce the reformed gas supplied to the fuel cell stack, and a stack exhaust gas discharged from the fuel cell stack are burned. A fuel cell module is known that includes a combustion section that In this fuel cell module, the raw fuel gas is reformed inside to generate fuel gas, and the fuel gas is supplied to the fuel cell stack.

JP 2016-24871 A

Normally, the inside of the fuel cell module is maintained at a high temperature, and the water contained in the fuel gas is supplied to the fuel cell stack in the gas phase. However, depending on the operating conditions of the fuel cell module and other conditions, the water contained in the fuel gas may condense. If the condensed water flows into the fuel cell stack, it will cause problems in the fuel cell stack, which is undesirable. If the fuel cell stack is arranged below the reforming section, there is a particular concern that condensed water may flow into the fuel cell stack.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object thereof is to provide a fuel cell module capable of suppressing the inflow of liquid-phase water into a fuel cell stack.

In order to achieve the above object, a fuel cell module according to claims 1 to 3 provides a fuel cell stack that generates power through an electrochemical reaction between an oxidant gas and a fuel gas, and a fuel cell stack that houses the fuel cell stack. a storage unit; a combustion unit provided above the fuel cell stack for burning stack exhaust gas discharged from the fuel cell stack and discharging combustion exhaust gas; and a combustion unit provided above the fuel cell stack. a reforming section having a reforming passage provided with a reforming catalyst layer for generating the fuel gas by steam reforming the raw fuel gas using the heat of the combustion exhaust gas; a fuel gas supply path for supplying the fuel gas sent from the reforming path to the fuel cell stack; and water provided in the fuel gas supply path for separating liquid phase water from the fuel gas. and a separation section.

In the fuel cell module according to the invention of Claims 1 to 3 , a water separator is provided in the fuel gas supply passage for supplying the fuel gas sent from the reforming passage to the fuel cell stack. Since liquid-phase water is separated from the fuel gas in this water separator, it is possible to suppress the inflow of liquid-phase water into the fuel cell stack.

In the fuel cell module according to the invention of claims 1 to 3 , the fuel gas supply path is connected to the fuel cell stack at a connecting portion, and the water separation portion is arranged vertically lower than the connecting portion. It is

In the fuel cell module according to the invention of Claims 1 to 3 , since the water separator is arranged vertically below the connecting portion between the fuel gas supply passage and the fuel cell stack, the water is separated by the water separator. Therefore, it is possible to suppress the water that has been collected from flowing into the connecting portion.

In the fuel cell module according to the invention of claim 5 , the accommodating portion is cylindrical, and the flue gas passage through which the flue gas passes and the reforming passage are arranged coaxially with the accommodating portion and between each other. It is composed of at least three tubular walls with gaps between them.

According to the fuel cell module according to the invention of claim 5 , the entire fuel cell module can be made compact.

In the fuel cell module according to the first aspect of the invention, the water separator is arranged at a position that overlaps with the fuel cell stack when viewed horizontally from the outside of the fuel cell stack.

According to the fuel cell module according to the first aspect of the invention, by arranging the water separator in this way, the water separator can be arranged without widening the vertical space of the housing.

In the fuel cell module according to the invention of claim 2 , the water separator is disposed vertically below the fuel cell stack and at a position overlapping the fuel cell stack when viewed in the vertical direction.

According to the fuel cell module according to the invention of claim 2 , by arranging the water separation section in this way, the water separation section can be arranged without widening the horizontal space of the accommodation section.

The fuel cell module according to the invention of claim 3 comprises a discharge channel for discharging the water separated by the water separating section from the accommodating section.

According to the fuel cell module according to the invention of claim 3 , the water separated by the separation section can be discharged from the storage section by the discharge channel.

The fuel cell module according to the invention of claim 3 comprises a water storage section provided outside the storage section for storing water discharged from the discharge channel.

According to the fuel cell module according to the invention of claim 3 , the water discharged from the discharge channel can be recovered in the water reservoir. In addition, since the water storage part is provided outside the storage part, it is possible to suppress the temperature drop in the storage part.

In the fuel cell module according to the invention of claim 4 , the water stored in the water storage portion is supplied to the reforming channel as reforming water.

According to the fuel cell module according to the invention of claim 4 , the amount of new supply of reforming water can be suppressed by reusing the water discharged from the discharge channel as reforming water.

As described in detail above, according to the fuel cell module of the present invention, it is possible to suppress the inflow of liquid-phase water into the fuel cell stack.

1 is a longitudinal sectional view of a fuel cell module of a first embodiment; FIG. FIG. 2 is an enlarged view of a main portion of the fuel cell module of the first embodiment; FIG. 2 is an enlarged view of a main portion of the fuel cell module of the first embodiment; FIG. 2 is an enlarged view of a main portion of the fuel cell module of the first embodiment; FIG. 2 is an enlarged view of a main portion of the fuel cell module of the first embodiment; FIG. 6 is an enlarged view of a main portion of a fuel cell module of a second embodiment;

[First embodiment]
A first embodiment of the present invention will be described below. In the drawings, the arrow X indicates the horizontal direction, and the arrow Z indicates the vertical direction.

<Fuel cell module>
As shown in FIG. 1, the fuel cell module M1 according to the first embodiment includes a fuel cell stack 10, a container 20, a heat insulating layer 130, and a heat insulating material 140. As shown in FIG.

<Fuel cell stack>
A solid oxide fuel cell (SOFC) is applied to the fuel cell stack 10 as an example. This fuel cell stack 10 has a plurality of vertically stacked flat plate cells 12 and a manifold 14 . The shape of the cell 12 may be any shape other than the flat plate shape, such as a cylindrical shape, a cylindrical flat plate shape, or the like. Each cell 12 has a fuel electrode, an electrolyte layer, and a cathode.

A fuel gas (reformed gas) is supplied to the fuel electrode of each cell 12 , and an oxidant gas is supplied to the air electrode of each cell 12 . Each cell 12 generates power through an electrochemical reaction between the fuel gas and the oxidant gas, and generates heat along with the power generation.

<Container>
The container 20 is composed of a plurality (nine) of pipe members 21-29. Each of the plurality of pipe members 21 to 29 is formed in a cylindrical shape having a perfectly circular cross section, and is made of a highly heat-conductive metal. The plurality of pipe members 21 to 29 are arranged in order from the inside to the outside of the container 20 . In this embodiment, as an example, the container 20 is composed of nine pipe members 21 to 29, but the container may be composed of other numbers (eight or less, ten or more) of pipe members.

The first pipe member 21 from the inside of the container 20 is provided from above the fuel cell stack 10 to the upper end of the container 20 . The second pipe member 22 and the third pipe member 23 are formed with a length corresponding to the upper portion of the first pipe member 21, and the second pipe member 22 extends from the outside of the first pipe member 21 to the upper portion of the pipe member 21. is joined to A fourth pipe member 24 is provided in the center of the container 20 in the height direction, and a fifth pipe member 25 and a sixth pipe member 26 are provided from the lower end to the upper end of the container 20. . A seventh pipe member 27 , an eighth pipe member 28 , and a ninth pipe member 29 are provided from the center to the upper end in the height direction of the container 20 .

The sixth pipe member 26 and the seventh pipe member 27 are connected via a horizontally extending connecting portion 31, and the fifth pipe member 25 and the eighth pipe member 28 are connected via a horizontally extending connecting portion 32. are concatenated. The upper end portion of the ninth pipe member 29 is fixed to the upper side surface of the third pipe member 23 via a connecting portion 33 extending in the horizontal direction.

The lower end of the fifth pipe member 25 is fixed to the bottom wall portion 34 and the lower end portion of the sixth pipe member 26 is fixed to the bottom wall portion 35 . The fuel cell stack 10 is placed on the bottom wall portion 34 , and the bottom wall portions 34 and 35 are fixed by spacers 36 .

The container 20 configured by the plurality of pipe members 21 to 29 has a vaporization section 40, a reforming section 60, a combustion section 90, a preheating section 100, and a heat exchange section 110 by function.

<Vaporization section>
As shown in FIG. 2, the vaporizing section 40 is composed of four-fold cylindrical walls 41-44. The innermost tubular wall 41 among the four tubular walls 41 to 44 is composed of the upper portion of the first tubular member 21 and the second tubular member 22, and the four tubular walls 41 to 44 The second tubular wall 42 from the inner side is composed of the third tubular member 23 . In addition, the innermost cylindrical wall 43 of the four-fold cylindrical walls 41-44 is formed by the upper portion of the fifth pipe member 25, and the outermost cylindrical wall of the four-layered cylindrical walls 41-44 A shaped wall 44 is constituted by the upper portion of the sixth tube 26 .
In the present embodiment, as an example, the vaporization section 40 is configured by four-fold cylindrical walls 41 to 44, but the vaporization section is configured by another number (three or less, five or more) of cylindrical walls. You may

The vaporizing section 40 constituted by the four-fold cylindrical walls 41 to 44 is provided above and coaxially with the reforming section 60, which will be described later. The four-fold cylindrical walls 41 to 44 forming the vaporizing section 40 have gaps between them, and from the inner side to the outer side of the four-layered cylindrical walls 41 to 44, there are heat insulating spaces 45, A vaporization channel 46, a combustion exhaust gas channel 47, and an oxidant gas channel 48 are formed in this order.

That is, the space inside the first cylindrical wall 41 is formed as a heat insulation space 45, and the gap between the first cylindrical wall 41 and the second cylindrical wall 42 is formed as a vaporization flow path 46. formed. Further, a gap between the second tubular wall 42 and the third tubular wall 43 is formed as a combustion exhaust gas flow path 47, and the third tubular wall 43 and the fourth tubular wall 44 is formed as an oxidant gas flow path 48 . Although the heat insulating space 45 is hollow in FIG. 2, the heat insulating space 45 may be filled with a heat insulating material 49 .

The vaporization channel 46 is formed so that the upper side in the vertical direction is the upstream side, and the raw fuel 161 supplied from the raw fuel supply pipe 50 flows through the vaporization channel 46 from the upper side in the vertical direction to the lower side. As the raw fuel 161 supplied from the raw fuel supply pipe 50, a mixture of hydrocarbon fuel and reforming water is used. As the hydrocarbon fuel contained in the raw fuel 161, for example, town gas is preferably used, but a gas containing a hydrocarbon such as propane as a main component may also be used. may be used.

The vaporization passage 46 is provided with a spiral member 51 spirally formed around the axial direction of the vaporization section 40 . is formed in a spiral shape.

A lower end portion of the combustion exhaust gas channel 47 communicates with a combustion chamber 94 (see FIG. 4) formed in the combustion section 90 via a combustion exhaust gas channel 66 formed in the reforming section 60, which will be described later. The flue gas flow path 47 is formed so that the vertically lower side is the upstream side, and the flue gas is discharged from the combustion section 90 and supplied to the flue gas flow path 47 through the flue gas flow path 66 of the reforming section 60. Combustion exhaust gas 166 flows vertically from the lower side to the upper side.

At the upper end of the flue gas flow path 47, a straightening plate 52 is provided which is annularly formed along the circumferential direction of the flue gas flow path 47. As shown in FIG. A plurality of orifices 53 are formed in the current plate 52 at intervals in the circumferential direction. The plurality of orifices 53 penetrate through the current plate 52 in the plate thickness direction. Note that the straightening plate 52 may be omitted.

An upper end portion of the oxidant gas channel 48 communicates with an oxidant gas channel 117 formed in the heat exchange section 110, which will be described later. The oxidizing gas channel 48 is formed with the upper side in the vertical direction as the upstream side. flows vertically from top to bottom.

<Modifying Department>
The reforming section 60 is composed of four-fold cylindrical walls 61 to 64 provided below the vaporization section 40 described above. The innermost tubular wall 61 among the four tubular walls 61 to 64 is formed by the lower part of the first tubular member 21, and the second tubular wall from the inside among the four tubular walls 61 to 64 is formed. The shaped wall 62 is constituted by the fourth tube 24 . In addition, among the four-fold tubular walls 61-64, the third tubular wall 63 from the inner side is formed by the central portion in the height direction of the fifth pipe member 25, and the four-fold tubular walls 61-64 Among them, the outermost cylindrical wall 64 is constituted by the central portion in the height direction of the sixth pipe member 26 .

The reforming section 60 constituted by the four-fold cylindrical walls 61 to 64 is provided above the later-described combustion section 90 (see FIG. 4) coaxially with the combustion section 90 . The quadruple cylindrical walls 61 to 64 forming the reforming section 60 have gaps therebetween. A heat insulating space 65, a flue gas channel 66, a reforming channel 67, and an oxidizing gas channel 68 are formed in this order from the inside to the outside of the four-fold cylindrical walls 61-64.
In the present embodiment, as an example, the reforming section 60 is configured by four-fold cylindrical walls 61 to 64, but another number (three or less, five or more) of cylindrical walls constitutes the reforming section. may be configured.

That is, the space inside the first cylindrical wall 61 is formed as a heat insulating space 65, and the gap between the first cylindrical wall 61 and the second cylindrical wall 62 is a flue gas flow path 66. is formed as A gap between the second tubular wall 62 and the third tubular wall 63 is formed as a reforming channel 67, and the third tubular wall 63 and the fourth tubular wall 64 is formed as an oxidizing gas flow path 68 .

The heat insulating space 65 communicates with the heat insulating space 45 of the vaporizing section 40 described above. Although the heat insulating space 65 is hollow in FIG. 3, the heat insulating space 65 may be filled with a heat insulating material 69 . A lower end portion of the combustion exhaust gas flow path 66 communicates with a combustion chamber 94 (see FIG. 4) formed in a combustion section 90, which will be described later. The flue gas flow path 66 is formed so that the vertically lower side is the upstream side, and the flue gas 168 discharged from the combustion unit 90 described later flows through the flue gas flow path 66 from the vertically lower side to the upper side. .

<Mixing section and dispersing section>
A mixing section 80 extending vertically upward is formed at the upper end of the reforming section 60 . The mixing section 80 is positioned between the vaporization section 40 and the reforming section 60 , that is, more specifically, above the reforming section 60 and radially outside the lower end portion of the vaporization section 40 . A connecting pipe 81 extends radially outward from a portion of the lower end portion of the vaporizing portion 40 in the circumferential direction. The connecting pipe 81 constitutes a connecting portion of the mixing portion 80 with the vaporizing portion 40, and the inner side of the connecting pipe 81 is formed as an orifice 82 penetrating in the horizontal direction. The connecting pipe 81 (orifice 82 ) is located radially outside the vaporization flow path 46 and communicates with the lower end portion of the vaporization flow path 46 . The mixing section 80 has only one connecting pipe 81 (orifice 82). The mixing portion 80 is provided with a facing wall portion 86 that is located on the reforming flow path 67 side (outside in the radial direction) of the orifice 82 and faces the orifice 82 .

An inlet (upper end) of the reforming channel 67 communicates with the vaporization channel 46 via a mixing section 80 and a connecting pipe 81 . The reforming channel 67 is formed so that the upper side in the vertical direction is the upstream side, and the raw fuel gas 162 supplied from the vaporization channel 46 flows through the reforming channel 67 from the upper side in the vertical direction to the lower side.

A partition plate 83 formed in an annular shape along the circumferential direction of the reforming channel 67 is provided at the inlet of the reforming channel 67 . A plurality of orifices 84 are formed in the partition plate 83 at regular intervals in the circumferential direction. The plurality of orifices 84 pass through the partition plate 83 in the plate thickness direction (vertical direction), and the raw fuel gas 162 flows into the reforming channel 67 through the plurality of orifices 84 . A plurality of partition plates 83 may be provided at intervals in the vertical direction.

A reforming catalyst layer 70 for generating the fuel gas 163 from the raw fuel gas 162 is provided in the reforming channel 67 over the entire length of the reforming channel 67 in the circumferential and axial directions. For the reforming catalyst layer 70, for example, a granular catalyst or a honeycomb catalyst supporting metal such as nickel, ruthenium, platinum, rhodium, etc. as an active metal is used.

An upper end portion of the oxidizing gas channel 68 communicates with the oxidizing gas channel 48 formed in the vaporizing section 40 described above. The oxidant gas channel 68 is formed with the upper side in the vertical direction as the upstream side, and the oxidant gas 164 supplied from the oxidant gas channel 48 of the vaporization unit 40 is supplied to the oxidant gas channel 68 . It flows vertically from top to bottom.

<Combustion part>
As shown in FIG. 4 , the combustion section 90 is provided below the reforming section 60 and has a peripheral wall section 91 , an ignition electrode 92 and a partition wall section 93 . The peripheral wall portion 91 is formed integrally with the remaining cylindrical walls 62 to 64 excluding the innermost cylindrical wall 61 of the four-fold cylindrical walls 61 to 64 forming the reforming portion 60 described above.

That is, of the four tubular walls 61 to 64, the remaining tubular walls 62 to 64, excluding the innermost tubular wall 61, extend downward with respect to the inner tubular wall 61. As shown in FIG. The downward extending portions of the cylindrical walls 62 to 64 are formed as the peripheral wall portion 91 of the combustion portion 90 . In the triple cylindrical walls 62 to 64 forming the peripheral wall portion 91, a reforming passage 67 of the reforming section 60 is formed extending between the cylindrical wall 62 and the cylindrical wall 63. An oxidizing gas flow path 68 of the reforming section 60 is formed extending between the cylindrical wall 63 and the cylindrical wall 64 .

The peripheral wall portion 91 is located above the fuel cell stack 10 and is provided coaxially with a preheating portion 100 that surrounds the fuel cell stack 10 to be described later. The inside of the peripheral wall portion 91 is formed as a combustion chamber 94, and the combustion chamber 94 communicates with the inner space 104 of the preheating section 100, which will be described later, and the combustion exhaust gas flow path 66 of the reforming section 60 described above. ing.

A tapered portion 95 is provided inside the peripheral wall portion 91 . The tapered portion 95 is formed integrally with the lower end portion of the innermost cylindrical wall 61 of the four-fold cylindrical walls 61 to 64 forming the reforming portion 60 described above. The tapered portion 95 protrudes from the reforming section 60 side to the combustion section 90 side, and is formed in a tapered shape whose diameter increases from the combustion section 90 side toward the reforming section 60 side.

The ignition electrode 92 protrudes into the combustion chamber 94 from the tip (lower end) of the tapered portion 95 and is arranged in the center of the combustion chamber 94 . The ignition electrode 92 is provided above the fuel cell stack 10 so as to be spaced apart from the fuel cell stack 10 . A pipe 150 is accommodated inside the first pipe member 21 constituting the above-described vaporization section 40 and reforming section 60, and inside this pipe 150 is a conductive section connected to the ignition electrode 92 and insulated by an insulator. 151 is inserted.

The partition wall portion 93 is annularly formed along the inner peripheral surface of the peripheral wall portion 91 . The partition wall 93 has a throttle hole 96 that opens between the ignition electrode 92 and the fuel cell stack 10 . A stack exhaust gas 165 discharged from the fuel cell stack 10 passes through the throttle hole 96 . The stack exhaust gas 165 that has passed through the throttle hole 96 is combusted by sparks formed between the ignition electrode 92 and the pipe 150 and the like. The flue gas 166 generated in the combustion chamber 94 is discharged upward (on the side opposite to the fuel cell stack 10 ) and flows along the tapered portion 95 into the flue gas passage 66 of the reforming section 60 .

<Preheating section>
The preheating section 100 (accommodating section) is composed of double cylindrical walls 101 and 102 provided below the combustion section 90 . The inner cylindrical wall 101 of the double cylindrical walls 101, 102 is composed of the lower part of the fifth pipe member 25, and the outer cylindrical wall 102 of the double cylindrical walls 101, 102 is composed of six It is constituted by the lower part of the second tube member 26 .

The preheating section 100 is provided around the fuel cell stack 10 and accommodates the fuel cell stack 10 . An inner space 104 is formed inside the preheating section 100 , and a preheating flow path 105 is formed between the double cylindrical walls 101 and 102 forming the preheating section 100 .

The preheating passage 105 is provided with a helical member 106 spirally formed around the axial direction of the preheating section 100 . is formed in a spiral shape.

The upper end of the preheating channel 105 communicates with the oxidizing gas channel 68 of the reforming section 60 described above, and the lower end of the preheating channel 105 connects to the bottom walls 34 and 35 shown in FIG. is communicated with the oxidant gas intake port 15 of the fuel cell stack 10 through an introduction passage 37 formed between the . The preheating channel 105 is formed so that the upper side in the vertical direction is the upstream side, and the oxidizing gas 164 supplied through the oxidizing gas channel 68 of the reforming section 60 is supplied to the preheating channel 105 from the upper side in the vertical direction. flow downwards.

Inside the preheating section 100 (inside the cylindrical wall 102), there is a fuel gas pipe 107 that connects the reforming channel 67 and the fuel gas inlet 16 (see FIG. 1) of the fuel cell stack 10. is provided. The reforming channel 67 and the inside of the fuel gas pipe 107 communicate with each other through an orifice 98 provided at the lower end of the reforming channel 67 . A temperature sensor S2 is provided near the outlet of the reforming channel 67 .

The fuel gas pipe 107 extends downward from the upper end communicating with the orifice 98 . A water separator 17 is provided at the lowest portion of the fuel gas pipe 107 . The water separating section 17 has a space continuous with the fuel gas pipe 107 and is formed below the fuel gas intake 16 and inside the preheating section 100 . The water separator 17 is arranged radially outside the fuel cell stack 10 and at a position overlapping the fuel cell stack 10 when viewed from the horizontal direction. If the fuel gas 163 contains liquid-phase water, the water falls into the water separator 17 and is separated from the fuel gas 163 .

A discharge flow path 18 is connected to the bottom of the water separation section 17 so as to communicate with the outside of the preheating section 100 through the bottom walls 34 and 35 . The discharge channel 18 is connected to the water reservoir 19 . The water storage part 19 is arranged outside the preheating part 100 and the cylindrical body part 141 . Condensed water discharged from the discharge passage 18 is stored in the water storage portion 19 .

The water storage unit 19 is provided with a water level sensor S1 for detecting the level of the stored water. An exhaust pipe P<b>1 and a water discharge pipe P<b>2 are connected to the water reservoir 19 . An opening/closing valve V1 is provided on the exhaust pipe P1, and an opening/closing valve V2 is provided on the water discharge pipe P2. The exhaust pipe P<b>1 is formed above the water reservoir 19 and is capable of exhausting gas that has flowed into the water reservoir 19 . The water discharge pipe P2 is connected to the lower portion of the water reservoir 19, and the water in the water reservoir 19 is discharged to the water discharge pipe P2 and then supplied to the raw fuel supply pipe 50 via a line (not shown). It is possible.

The water level sensor S1, the temperature sensor S2, and the open/close valves V1 and V2 are connected to the controller SS. The control unit SS includes a CPU, ROM, RAM, memory, and the like. The memory stores data, procedures, and the like necessary for processing during operation. The water level sensor S1 outputs the detected water level to the controller SS. The temperature sensor S2 outputs the detected temperature to the controller SS. The opening/closing of the opening/closing valves V1 and V2 is controlled by the controller SS.

<Heat exchange section>
As shown in FIG. 1, the heat exchange section 110 is composed of triple cylindrical walls 111 to 113 provided around the reforming section 60 and the vaporizing section 40 described above. The inner tubular wall 111 of the triple tubular walls 111-113 is constituted by the seventh tubular member 27, and the central tubular wall 112 of the triple tubular walls 111-113 is constituted by the eighth tubular member 28. The outer tubular wall 113 of the triple tubular walls 111 to 113 is composed of the ninth tubular member 29 .
In the present embodiment, as an example, the heat exchange section 110 is configured by the triple cylindrical walls 111 to 113, but the heat exchange section is configured by another number (two or less, four or more) of cylindrical walls. may be configured.

The triple cylindrical walls 111 to 113 forming the heat exchange section 110 have gaps therebetween. Between the inner cylindrical wall 111 and the central cylindrical wall 112, an oxidizing gas flow path 118 is formed, and between the outer cylindrical wall 113 and the central cylindrical wall 112, A combustion exhaust gas flow path 117 is formed.

The oxidizing gas channel 118 is provided with a spiral member 121 spirally formed around the axial direction of the heat exchange section 110 . It is formed spirally around the axis of 110 . Similarly, the flue gas flow path 117 is provided with a spiral member 120 spirally formed around the axial direction of the heat exchanging section 110, and the flue gas flow path 117 is provided with a heat exchanging member 120 by the spiral member 120. It is formed spirally around the axial direction of the portion 110 .

An oxidant gas supply pipe 122 (see FIG. 1) extending radially outward of the container 20 is connected to the lower end of the oxidant gas channel 118 . A gap between the connecting portion 31 and the connecting portion 32 is formed as a connecting flow path 38 extending in the radial direction of the container 20 , and the upper end portion of the oxidizing gas flow path 118 is connected to the above-described connecting flow path 38 via the connecting flow path 38 . is communicated with the oxidant gas flow path 48 formed in the vaporization section 40 of the . The oxidant gas channel 118 is formed with the vertically lower side as the upstream side, and the oxidant gas 164 supplied from the oxidant gas supply pipe 122 (see FIG. 1) is supplied to the oxidant gas channel 118 . flows vertically from bottom to top.

In addition, the gap between the connecting portion 32 and the connecting portion 33 is formed as a connecting flow path 39 extending in the radial direction of the container 20, and the upper end portion of the flue gas flow path 117 is connected through the connecting flow path 39. It communicates with the combustion exhaust gas flow path 47 formed in the above-described vaporizing section 40 . A gas discharge pipe 123 (see FIG. 1) extending radially outward of the container 20 is connected to the lower end of the flue gas flow path 117 . The flue gas channel 117 is formed with the upper side in the vertical direction as the upstream side. flow to the side.

<Heat insulation layer>
As shown in FIG. 1 , the reforming section 60 and the vaporization section 40 and the heat exchange section 110 are separated from each other in the radial direction of the container 20 . A cylindrical heat insulating layer 130 is interposed between them. The heat insulating layer 130 covers the vaporizing section 40 and the reforming section 60 from the outside.

<Insulation material>
The heat insulating material 140 has a cylindrical body portion 141 and disk-shaped upper and lower portions 142 and 143 and covers the container 20 . That is, the body part 141 is provided around the container 20 and covers the container 20 from the outside. The upper portion 142 covers the main body portion 141 from above in the vertical direction and is provided around the upper portion of the container 20 . The upper portion 142 is fixed by a fixing member 144 from above in the vertical direction. The lower portion 143 covers the container 20 and the main body portion 141 from below in the vertical direction. The surface of this heat insulating material 140 is covered with a cover sheet 145 .

Next, operation of the fuel cell module M1 according to the first embodiment will be described.

When the raw fuel 161 in which the hydrocarbon fuel and the reforming water are mixed is supplied to the raw fuel supply pipe 50 shown in FIG. . Then, the raw fuel 161 flows from the upper side to the lower side in the vertical direction through the spirally formed vaporization flow path 46 . At this time, in the vaporizing section 40, the combustion exhaust gas 166 discharged from the combustion section 90 (see FIG. 4) flows through the combustion exhaust gas flow path 47 from the bottom to the top in the vertical direction. When the combustion exhaust gas 166 flows through the combustion exhaust gas channel 47 adjacent to the vaporization channel 46, heat is exchanged between the raw fuel 161 flowing through the vaporization channel 46 and the combustion exhaust gas 166 (from the combustion exhaust gas 166 to the raw fuel 161). heat of vaporization is given). In the vaporization passage 46, the raw fuel 161 is vaporized to generate raw fuel gas 162 (see FIG. 3).

As shown in FIG. 3, the raw fuel gas 162 vaporized in the vaporization passage 46 passes through an orifice 82 formed inside the connecting pipe 81 and passes through the mixing section 80 formed above the reforming section 60. It flows into the inner space 85 . At this time, the raw fuel gas 162 vaporized in the vaporization passage 46 is increased in flow velocity when passing through the orifice 82 inside the connecting pipe 81 and becomes a jet flow, and is formed into a jet flow, which is formed on the opposite wall portion 86 on the radially outer side of the mixing portion 80 . collide with When the raw fuel gas 162 collides with the opposing wall portion 86, a turbulent flow is generated, and the hydrocarbon-based gas and water vapor contained in the raw fuel gas 162 are mixed.

The raw fuel gas 162 mixed in this manner collides with the opposing wall portion 86 to change direction from the radially outer side to the vertically downward direction, and passes through a plurality of orifices 84 formed at the inlet of the reforming channel 67 . It flows into the reforming channel 67 through . Since the plurality of orifices 84 are arranged at regular intervals in the circumferential direction of the reforming passage 67 , the raw fuel gas 162 is supplied to the reforming passage 67 by passing through the plurality of orifices 84 . Inflow is dispersed in the circumferential direction.

At this time, in the reforming section 60, the combustion exhaust gas 166 discharged from the combustion section 90 (see FIG. 4) flows through the combustion exhaust gas flow path 66 from the bottom to the top in the vertical direction. When the flue gas 166 flows through the flue gas channel 66 adjacent to the reforming channel 67 , heat is exchanged between the raw fuel gas 162 flowing through the reforming channel 67 and the flue gas 166 . In the reforming passage 67 , the heat of the flue gas 166 is used to generate the fuel gas 163 (reformed gas) from the raw fuel gas 162 by the reforming catalyst layer 70 .

The fuel gas 163 generated in the reforming channel 67 passes through the orifice 98 formed in the partition plate 97 and flows into the fuel gas pipe 107, as shown in FIG. This fuel gas 163 is then supplied to the fuel gas inlet 16 (see FIG. 1) of the fuel cell stack 10 through the fuel gas pipe 107 .

Here, when the water contained in the fuel gas 163 is condensed, the condensed water falls into the water separating portion 17, is discharged from the discharge passage 18, and is stored in the water storing portion 19. FIG. The water level of the water reservoir 19 is detected by the water level sensor S1 and output to the controller SS. When the detected water level L is higher than the water level L1 at the attachment portion of the water discharge pipe P2, the controller SS opens the open/close valve V2. Further, when the detected water level becomes equal to or lower than the water level L1, the controller SS closes the open/close valve V2. When the opening/closing valve V2 is opened, water is discharged from the water reservoir 19 to the water discharge pipe P2, and the discharged water is supplied to the raw fuel supply pipe 50 while the flow rate is adjusted by a pump (not shown) or the like. .

Further, the control unit SS removes gas remaining in the water reservoir 19 when the fuel cell module M1 is activated. It is conceivable that the gas flows back from the water reservoir 19 through the discharge channel 18 during steady operation and flows into the fuel cell stack 10. If air is mixed in the residual gas, the fuel cell This is because the cell stack 10 may deteriorate. Specifically, when the predetermined reforming temperature (for example, about 600°) output from the temperature sensor S2 is exceeded, the open/close valve V1 is opened to allow the residual gas in the water reservoir 19 to flow into the reforming channel. 67, and then closes the on-off valve V1.

On the other hand, in the heat exchange section 110 shown in FIG. 1, the oxidizing gas 164 is supplied to the oxidizing gas flow path 117 through the oxidizing gas supply pipe 122 . The oxidizing gas 164 flows vertically upward through the spirally formed oxidizing gas flow path 117 . At this time, in the heat exchange section 110, the flue gas 166 discharged from the combustion section 90 flows through the flue gas passage 118 from the upper side to the lower side in the vertical direction. This combustion exhaust gas 166 is discharged outside the fuel cell module M1 through the gas discharge pipe 123 .

As shown in FIG. 3 , when the flue gas 166 flows through the flue gas channel 118 adjacent to the oxidizing gas channel 117 , the oxidizing gas 164 flowing through the oxidizing gas channel 117 and the flue gas 166 become heat is exchanged. Then, the temperature of the combustion exhaust gas 166 discharged to the outside of the fuel cell module M1 is lowered, and heat radiation to the outside of the fuel cell module M1 is suppressed. On the other hand, the oxidant gas 164 absorbs the heat of the flue gas 166 and is preheated. The oxidizing gas 164 preheated in the heat exchange section 110 flows into the oxidizing gas flow path 48 of the vaporizing section 40 through the connecting flow path 38, and then flows into the oxidizing gas flow path 48 of the vaporizing section 40 and the reforming gas. It flows vertically from the upper side to the lower side through the oxidant gas channel 68 of the portion 60 .

In the vaporization section 40 shown in FIG. 2, as described above, the combustion exhaust gas 166 discharged from the combustion section 90 flows through the combustion exhaust gas flow path 47 from the bottom to the top in the vertical direction. When the flue gas 166 flows through the flue gas channel 47 adjacent to the oxidizing gas channel 48 , heat is exchanged between the oxidizing gas 164 flowing through the oxidizing gas channel 48 and the flue gas 166 . is further preheated.

Similarly, in the reforming section 60, the flue gas 166 discharged from the combustion section 90 flows through the flue gas flow path 66 from the bottom to the top in the vertical direction. When the flue gas 166 flows into the flue gas channel 66 on the opposite side of the oxidizing gas channel 68 sandwiching the reforming channel 67, the oxidizing gas 164 and the flue gas 166 flowing through the oxidizing gas channel 68 are reformed. Heat is exchanged through the quality channel 67 (reforming catalyst layer 70), and the oxidant gas 164 is also preheated by this.

The oxidizing gas 164 preheated by flowing through the oxidizing gas flow paths 48 and 68 in this way flows into the preheating flow path 105 shown in FIG. Direction from top to bottom. The oxidant gas 164 flowing through this preheating flow path 105 is further preheated by the heat of the fuel cell stack 10 . The oxidizing gas 164 preheated in the preheating passage 105 is supplied to the oxidizing gas inlet 15 of the fuel cell stack 10 .

As described above, when the fuel gas is supplied to the fuel gas inlet 16 of the fuel cell stack 10 and the oxidant gas is supplied to the oxidant gas inlet 15 of the fuel cell stack 10, the fuel cell In the cell stack 10, each cell 12 generates power through an electrochemical reaction between the oxidant gas and the fuel gas. Each cell 12 also generates heat as it generates power.

A stack exhaust gas 165 including a fuel electrode exhaust gas and an air electrode exhaust gas is discharged from the fuel cell stack 10 . A stack exhaust gas 165 discharged from the fuel cell stack 10 flows into a combustion chamber 94 formed inside the combustion portion 90 through a throttle hole 96 formed in the partition wall portion 93 . At this time, the stack exhaust gas 165 including the anode exhaust gas and the cathode exhaust gas is mixed by passing through the throttle hole 96 .

The stack exhaust gas 165 that has flowed into the combustion chamber 94 contains unreacted hydrogen and oxygen in each cell 12, and this stack exhaust gas 165 containing hydrogen is formed between the ignition electrode 92 and the pipe 150 and the like. It is burned by the spark that is emitted. Since the ignition electrode 92 is separated from the fuel cell stack 10 in the vertical direction, the stack exhaust gas 165 is combusted at a position away from the fuel cell stack 10 .

When the stack exhaust gas 165 is combusted in the combustion chamber 94 in this manner, combustion exhaust gas 166 is generated in the combustion chamber 94 . The flue gas 166 generated in the combustion chamber 94 is discharged upward (on the side opposite to the fuel cell stack 10 ) and flows along the tapered portion 95 into the flue gas passage 66 of the reforming section 60 . Further, the flue gas 166 discharged from the combustion section 90 and flowing into the flue gas flow path 66 of the reforming section 60 passes through the flue gas flow path 66 of the reforming section 60 and the flue gas flow path of the vaporizing section 40 as described above. 47, the connecting channel 39, and the flue gas channel 118 of the heat exchanging part 110, the exhaust gas is discharged to the outside of the fuel cell module M1 through the gas discharge pipe 123. FIG.

Next, the action and effects of the first embodiment of the present invention will be described.

As detailed above, according to the fuel cell module M1 of the first embodiment, the water separator 17 is provided at the lowest portion of the fuel gas pipe 107 . When the water vapor contained in the fuel gas 163 condenses in the fuel gas pipe 107, or when the liquid-phase water supplied from the raw fuel supply pipe 50 is discharged from the reforming channel 67 without being vaporized, the fuel The gas 163 contains water in the liquid phase, which falls into the water separator 17 and is separated from the fuel gas 163 . Therefore, the inflow of liquid-phase water into the fuel cell stack 10 can be suppressed.

In addition, since the water separator 17 is arranged vertically below the fuel gas intake 16, which is the connecting portion with the fuel cell stack 10, the water separated by the water separator 17 is removed from the fuel gas. Flowing into the inlet 16 can be suppressed.

In addition, since the water separator 17 is arranged radially outside of the fuel cell stack 10 and at a position overlapping the fuel cell stack 10 when viewed from the horizontal direction, the water separator 17 can separate water without increasing the vertical space of the preheating unit 100 . A separating portion 17 can be arranged.

A discharge channel 18 communicating with the outside of the preheating unit 100 is connected to the bottom of the water separation unit 17, and the discharge channel 18 is connected to the water storage unit 19, so that the separated water can be discharged. The water can be discharged to the outside of the preheating section 100 and can be stored in the water storage section 19 .

Furthermore, since the water stored in the water storage part 19 is supplied to the raw fuel supply pipe 50, the water discharged from the discharge flow path 18 is reused as reformed water, thereby increasing the new supply amount of reformed water. can be suppressed.

Although the exhaust pipe P1 is provided in the water reservoir 19 in this embodiment, the exhaust pipe P1 is not an essential component. As a method for replacing the gas remaining in the water storage section 19 with fuel gas, the open/close valve V2 is closed to fill the water storage section 19 with water (state in which no gas is stored) at startup, and then the temperature sensor S2 outputs the When the temperature exceeds a predetermined reforming temperature (for example, about 600°), the opening/closing valve V2 may be opened to allow the fuel gas to flow into the water reservoir 19 .

Moreover, in the present embodiment, the water storage unit 19 is provided to store the water separated by the water separation unit 17, but the water storage unit 19 is not an essential component. The water from the discharge channel 18 may be discarded without providing the water reservoir 19 .

[Second embodiment]
Next, a second embodiment of the invention will be described. In addition, in this embodiment, the same code|symbol is attached|subjected about the part similar to 1st Embodiment, and the detailed description is abbreviate|omitted. In this embodiment, the position of the water separator is different from that in the first embodiment.

As shown in FIG. 6, the water separator 17-2 of the fuel cell module M2 of this embodiment is provided below the fuel cell stack 10. As shown in FIG. The water separator 17-2 has a space that is continuous with the fuel gas pipe 107, and constitutes the downstream end of the fuel gas pipe 107. As shown in FIG. The fuel gas intake 16 is provided above the water separator 17-2. The water separating section 17-2 is arranged at a position overlapping the fuel cell stack 10 when viewed from the axial direction of the preheating section 100. As shown in FIG. If the fuel gas 163 contains water in the liquid phase, the water falls into the water separating section 17-2 and is separated from the fuel gas 163. FIG.

A discharge channel 18 is connected to the bottom of the water separating section 17-2 to communicate with the outside of the preheating section 100 through the bottom wall sections 34 and 35. As shown in FIG. The configuration downstream of the discharge channel 18 is the same as in the first embodiment.

The raw fuel supply pipe 50-2 of this embodiment can also achieve the same effect as the first embodiment. In addition, since the water separator 17-2 is arranged below the fuel cell stack 10 and overlapping the fuel cell stack 10 when viewed from the axial direction of the preheating unit 100, the water separation unit 17-2 is arranged in the radial direction of the preheating unit 100. The water separator 17-2 can be arranged without increasing the space.

Although the first and second embodiments of the present invention have been described above, the present invention is not limited to the above, and can be modified in various ways without departing from the gist of the present invention. Of course there is.

M1, M2 fuel cell module 10 fuel cell stack 16 fuel gas intake (connection)
17 water separator 18 discharge channel 19 water reservoirs 21, 24, 25 tubular body (cylindrical wall)
100 preheating section (accommodating section)
90 combustion section 60 reforming section 67 reforming channel 66 flue gas channel 107 fuel gas pipe (fuel gas supply channel)

Claims (5)

a fuel cell stack that generates electricity through an electrochemical reaction between an oxidant gas and a fuel gas;
an accommodation unit that accommodates the fuel cell stack;
a combustion unit provided above the fuel cell stack for burning stack exhaust gas discharged from the fuel cell stack and discharging combustion exhaust gas;
a reforming channel provided above the fuel cell stack and provided with a reforming catalyst layer for generating the fuel gas by steam reforming the raw fuel gas using the heat of the combustion exhaust gas; a reforming unit having
a fuel gas supply passage connected to the fuel cell stack at a connection portion and provided in the accommodation portion for supplying the fuel gas delivered from the reforming passage to the fuel cell stack;
is provided in the fuel gas supply path, is positioned vertically below the connecting portion, is positioned outside the fuel cell stack in the horizontal direction and overlaps the fuel cell stack when viewed from the horizontal direction, and is liquid-phase water; from the fuel gas; and
A fuel cell module with a fuel cell stack that generates electricity through an electrochemical reaction between an oxidant gas and a fuel gas;
an accommodation unit that accommodates the fuel cell stack;
a combustion unit provided above the fuel cell stack for burning stack exhaust gas discharged from the fuel cell stack and discharging combustion exhaust gas;
a reforming channel provided above the fuel cell stack and provided with a reforming catalyst layer for generating the fuel gas by steam reforming the raw fuel gas using the heat of the combustion exhaust gas; a reforming unit having
a fuel gas supply passage connected to the fuel cell stack at a connection portion and provided in the accommodation portion for supplying the fuel gas delivered from the reforming passage to the fuel cell stack;
It is provided in the fuel gas supply path, is arranged vertically below the connecting portion, is arranged vertically below the fuel cell stack and overlaps with the fuel cell stack when viewed in the vertical direction, and has a liquid phase. a water separator that separates water from the fuel gas;
A fuel cell module with a fuel cell stack that generates electricity through an electrochemical reaction between an oxidant gas and a fuel gas;
an accommodation unit that accommodates the fuel cell stack;
a combustion unit provided above the fuel cell stack for burning stack exhaust gas discharged from the fuel cell stack and discharging combustion exhaust gas;
a reforming channel provided above the fuel cell stack and provided with a reforming catalyst layer for generating the fuel gas by steam reforming the raw fuel gas using the heat of the combustion exhaust gas; a reforming unit having
a fuel gas supply passage connected to the fuel cell stack at a connection portion and provided in the accommodation portion for supplying the fuel gas delivered from the reforming passage to the fuel cell stack;
a water separation section provided in the fuel gas supply passage , arranged vertically below the connection section, and separating liquid phase water from the fuel gas;
a discharge channel for discharging the water separated by the water separation unit from the storage unit;
a water storage portion provided outside the storage portion for storing water discharged from the discharge channel;
A fuel cell module with 4. The fuel cell module according to claim 3 , wherein water stored in said water storage portion is supplied to said reforming channel as reformed water. The storage section is cylindrical, and the flue gas flow path through which the combustion exhaust gas passes and the reforming flow path are arranged coaxially with the storage section and have at least three layers of cylindrical shapes with a gap therebetween. 5. The fuel cell module according to any one of claims 1 to 4 , which is constituted by a cylindrical wall.

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