Fuel cell system

Abstract

To provide a fuel cell system capable of suppressing deterioration of a fuel cell stack due to an evaporated material.SOLUTION: A fuel cell system 10 includes a fuel cell unit 11, a storage tank 20, and a reformer 30. The fuel cell unit 11 includes a fuel cell stack 12, and includes an oxidant gas supply part that supplies air sucked through an air cleaner 13a as an oxidant gas to the fuel cell stack 12. The storage tank 20 includes a tank main body 21 and a charging slot 22. A line for dividing the storage tank 20 into an upper half and a lower half of a vertical direction Z is a center line L of the fuel cell system 10. The charging slot 22 is positioned at an upper side of th center line L. The air cleaner 13a is positioned at a lower side of the center line L.SELECTED DRAWING: Figure 5

Description

Technical Field

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[0001] The present invention relates to a fuel cell system.

Background Art

[0002] A fuel cell stack as a power generation device generates electrical energy by the reaction of a fuel gas and an oxidant gas. When using a fuel cell stack as a power generation device, in addition to the fuel cell stack, a storage tank for storing the raw material of the fuel gas as a liquid and a reformer for generating a reformed substance produced by reforming the raw material stored in the storage tank are required. As an example of the layout of the fuel cell stack, the storage tank, and the reformer, for example, Patent Document 1 discloses a layout in which a tank is arranged above the fuel cell stack and the reformer.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, when charging a liquid raw material into the tank, a vaporized substance of the raw material is generated. This vaporized substance may deteriorate the fuel cell stack.

Means for Solving the Problems

[0005] A fuel cell system to solve the above problems comprises: a fuel cell unit having a fuel cell stack and an oxidant gas supply unit that supplies air inhaled through an air intake as an oxidant gas to the fuel cell stack; a storage tank arranged horizontally alongside the fuel cell unit and having a tank body for storing fuel gas raw materials as liquid, and an inlet for introducing the raw materials into the tank body; and a reformer that supplies a reformed substance produced by reforming the raw materials supplied from the storage tank as the fuel gas to the fuel cell stack. In this fuel cell system, if the line dividing the storage tank into an upper and lower half in the vertical direction is the centerline of the fuel cell system, the inlet is located above the centerline and the air intake is located below the centerline.

[0006] According to this, when liquid raw materials are introduced into the tank body through the inlet, some of the liquid raw materials vaporize, generating vaporized substances, which tend to remain around the inlet. However, the air intake is located below the inlet. Therefore, the amount of vaporized substances remaining around the air intake is less than the amount remaining around the inlet.

[0007] When the fuel cell system is activated and the oxidizer gas supply unit is activated, air is drawn into the oxidizer gas supply unit through the intake port and supplied to the fuel cell stack as oxidizer gas. At this time, the amount of vaporized material remaining around the intake port is less than the amount of vaporized material remaining around the inlet port. As a result, the amount of vaporized material drawn into the oxidizer gas supply unit through the intake port can be reduced, and therefore the amount of vaporized material drawn into the fuel cell stack can be reduced. This suppresses the deterioration of the fuel cell stack due to vaporized material.

[0008] A fuel cell system to solve the above problems comprises: a fuel cell unit having an oxidant gas supply unit that supplies air inhaled through an air intake as an oxidant gas to a fuel cell stack, a heat exchanger that exchanges heat between outside air and a heat exchange medium, and a fan that blows air toward the heat exchanger, thereby cooling the heat exchange medium and the fuel cell stack; a storage tank arranged horizontally alongside the fuel cell unit, having a tank body that stores the raw materials for the fuel gas as a liquid, and having an inlet for introducing the raw materials into the tank body; and a reformer that supplies a reformed substance produced by reforming the raw materials supplied from the storage tank to the fuel cell stack as the fuel gas. The gist of this fuel cell system is that the direction of airflow generated by the fan is from the inside to the outside of the fuel cell unit, and in the direction of airflow, the inlet is located downstream of the fan.

[0009] According to this, when liquid raw materials are introduced into the tank body through the inlet, some of the liquid raw materials vaporize, generating vaporized substances, and these vaporized substances tend to remain around the inlet.

[0010] When the fuel cell system is activated, a fan is driven to cool the fuel cell stack. The fan blows air towards the heat exchanger and also creates an airflow from inside the fuel cell unit outwards. At this time, the inlet is located downstream of the fan in the direction of airflow, so any vaporized material remaining around the inlet is blown downstream of the fan. As a result, the amount of vaporized material remaining around the fuel cell system can be reduced. Therefore, the amount of vaporized material drawn into the oxidizer gas supply section through the air intake can be reduced, and thus the amount of vaporized material drawn into the fuel cell stack can be reduced. This suppresses the deterioration of the fuel cell stack due to vaporized material.

[0011] In a fuel cell system, the fuel cell unit and the storage tank are arranged adjacent to each other in the horizontal direction, and the inlet and the air intake may be located on opposite sides of each other in the horizontal direction, with the fuel cell unit and the storage tank in between.

[0012] This makes it easier to increase the horizontal separation distance between the air intake and the air inlet. As a result, the amount of vaporized material drawn into the oxidizer gas supply unit and the fuel cell stack through the air intake can be further reduced.

[0013] In the fuel cell system, the storage tank, the fuel cell unit, and the reformer are housed in a container, and in the vertical direction, the reformer may be located above the fuel cell unit in the vertical direction, while the air intake may be located below the reformer in the vertical direction.

[0014] According to this, the reformer acts as a physical shield interposed between the inlet and the intake in the vertical direction. Therefore, the reformer makes it difficult for vaporized material to spread around the intake. As a result, the amount of vaporized material drawn into the fuel cell stack from the intake via the oxidizer gas supply unit can be reduced. [Effects of the Invention]

[0015] According to the present invention, it is possible to suppress the deterioration of the fuel cell stack due to vaporized raw materials. [Brief explanation of the drawing]

[0016] [Figure 1] This is a schematic perspective view showing the fuel cell system of the first embodiment. [Figure 2] This is a schematic partial fractured perspective view showing a fuel cell unit. [Figure 3] This is a schematic perspective view of a fuel cell system. [Figure 4] This is a conceptual diagram of a fuel cell system. [Figure 5]It is a front view showing a fuel cell system with the front surface of the container opened. [Figure 6] It is a perspective view schematically showing a fuel cell system of a second embodiment. [Figure 7] It is a partially cut-away plan view schematically showing a fuel cell system of a second embodiment. [Figure 8] It is a partially cut-away plan view schematically showing a fuel cell system of another example. [Figure 9] It is a front view schematically showing a fuel cell system of another other example.

Embodiments for Carrying out the Invention

[0017] [First Embodiment] Hereinafter, a first embodiment in which a fuel cell system is embodied will be described according to FIGS. 1 to 5.

[0018] As shown in FIG. 1, the fuel cell system 10 has a fuel cell unit 11, a storage tank 20, and a reformer 30. The fuel cell system 10 may have a container 40 that houses the fuel cell unit 11, the storage tank 20, and the reformer 30. The fuel cell system 10 is a stationary emergency power source.

[0019] <Fuel Cell Unit> As shown in FIG. 2, the fuel cell unit 11 has a fuel cell stack 12, an oxidant gas supply unit 13, a heat exchanger 14, and a fan 15. The fuel cell unit 11 may have a housing 16.

[0020] <Housing> The enclosure 16 has a bottom plate 16a, a top plate 16b, and a cylindrical peripheral wall 16c connecting the periphery of the bottom plate 16a and the periphery of the top plate 16b. Assuming the fuel cell system 10 is placed on a horizontal plane, the direction of gravity is indicated by the Z axis, and the directions along the horizontal plane are indicated by the X and Y axes. The X, Y, and Z axes are orthogonal to each other. In the following description, the direction parallel to the Z axis is also called the vertical direction Z, and the direction parallel to the X axis is also called the horizontal direction X. The direction parallel to the Y axis is also called the depth direction Y. Therefore, the depth direction Y is a direction that is orthogonal to both the horizontal direction X and the vertical direction Z.

[0021] In the housing 16, the bottom plate 16a and the top plate 16b face each other in the vertical direction Z. The peripheral wall 16c has a first side wall 16d and a second side wall 16e facing each other in the horizontal direction X, and a third side wall 16f and a fourth side wall 16g facing each other in the depth direction Y. The outer surface of the third side wall 16f is the front surface in the depth direction Y, and the outer surface of the fourth side wall 16g is the rear surface in the depth direction Y. Multiple ventilation openings 16h are arranged in the third side wall 16f of the housing 16. Each of the multiple ventilation openings 16h penetrates the third side wall 16f in the thickness direction. Therefore, the ventilation openings 16h open to the front surface of the fuel cell unit 11. The housing 16 houses the fuel cell stack 12, the oxidizer gas supply unit 13, the heat exchanger 14, and the fan 15.

[0022] <Fuel cell stack> The fuel cell stack 12 is a stack of multiple fuel cell cells. Each fuel cell is a solid molecular fuel cell. The fuel cell stack 12 generates electricity when supplied with hydrogen gas, which is the fuel gas, and an oxidizer gas. The oxidizer gas is oxygen from the air.

[0023] <Oxidizing gas supply unit> The oxidant gas supply unit 13 is an air compressor. The oxidant gas supply unit 13 is supported by a support member 17. The support member 17 is attached, for example, to the first side wall 16d. The fuel cell stack 12 is located below the support member 17. The oxidant gas supply unit 13 inhales and compresses air, and supplies the compressed air to the fuel cell stack 12. The oxidant gas supply unit 13 inhales air through an air cleaner 13a. The air cleaner 13a is the air intake of the oxidant gas supply unit 13. Therefore, it can be said that the oxidant gas supply unit 13 supplies the air inhaled through the air cleaner 13a as oxidant gas to the fuel cell stack 12. The air cleaner 13a of the oxidant gas supply unit 13 faces the third side wall 16f.

[0024] <Heat exchangers and fans> The heat exchanger 14 performs heat exchange between the outside air and the heat exchange medium. The heat exchanger 14 is located on the fourth side wall 16g of the housing 16. The heat exchanger 14 has a circulation channel (not shown) that circulates the heat exchange medium between itself and the fuel cell stack 12. An example of the heat exchange medium is cooling water, but other materials such as LLC may also be used. The circulation channel has a forward path, a return path, and a pump. The forward path is a channel for flowing the heat exchange medium from the heat exchanger 14 to the fuel cell stack 12. The return path is a channel for flowing the heat exchange medium from the fuel cell stack 12 to the heat exchanger 14. The pump circulates the heat exchange medium in the circulation channel.

[0025] The heat exchange medium, circulating through the circulation channel and flowing into the fuel cell stack 12 via the forward path, absorbs the heat generated in the fuel cell stack 12 and cools it. The heat exchange medium, flowing into the heat exchanger 14 via the return path, is cooled by heat exchange with the outside air.

[0026] The fan 15 is located on the fuel cell stack 12 side of the heat exchanger 14 in the depth direction Y. The fan 15 blows air toward the heat exchanger 14. The heat exchanger 14, the fan 15, and the vent 16h are aligned in the depth direction Y.

[0027] When the fuel cell stack 12 generates power, the fan 15 is driven, drawing air from outside the housing 16 into the housing 16 through the vent 16h. Inside the housing 16, an airflow is generated from the vent 16h toward the fan 15. The direction F of the airflow generated by the fan 15 is from the third side wall 16f toward the fourth side wall 16g. The direction F of the airflow generated by the fan 15 is from inside the fuel cell unit 11 toward the outside. Specifically, the direction F of the airflow generated by the fan 15 is from the vent 16h toward the heat exchanger 14. The heat exchange medium that flows into the heat exchanger 14 is then forcibly cooled by heat exchange with the outside air due to the airflow from the fan 15. Therefore, when the heat exchange medium is cooled by the airflow from the fan 15, the fuel cell stack 12 is cooled by the cooled heat exchange medium.

[0028] <Storage Tank> As shown in Figure 3, the storage tank 20 is aligned with the fuel cell unit 11 in the horizontal direction X. The storage tank 20 has a tank body 21 and an inlet 22.

[0029] The tank body 21 stores the fuel gas raw material in liquid form. An example of a raw material is methanol. Methanol is an organic solvent. Methanol is highly volatile. Furthermore, methanol has a low reforming temperature and a high energy density. In addition, methanol is liquid at room temperature. The tank body 21 is preferably made of a metal that does not leach out with methanol, but it may also be made of a resin that does not leach out with methanol.

[0030] The dimension of the tank body 21 in the vertical direction Z is greater than the dimension of the fuel cell unit 11 in the vertical direction Z. The tank body 21 has a first side surface 21a and a second side surface 21b. The first side surface 21a is located at one end of the tank body 21 in the horizontal direction X, and the second side surface 21b is located at the other end in the horizontal direction X. The tank body 21 has a third side surface 21c and a fourth side surface 21d. The third side surface 21c is located at one end of the tank body 21 in the depth direction Y, and the fourth side surface 21d is located at the other end in the depth direction Y. The third side surface 21c is the front of the tank body 21, and the fourth side surface 21d is the rear of the tank body 21. The tank body 21 has an upper end surface 21e. The upper end surface 21e is located above the top plate 16b of the housing 16, and consequently above the air cleaner 13a.

[0031] The inlet 22 is provided for introducing liquid methanol into the tank body 21. The inlet 22 is located on the upper end surface 21e of the tank body 21. Therefore, the inlet 22 is located above the air cleaner 13a. The inlet 22 is located closer to the first side surface 21a than the midpoint of the horizontal direction X on the upper end surface 21e. In detail, the inlet 22 is aligned with the first side surface 21a on the upper end surface 21e. Also, the inlet 22 is located midpoint of the depth direction Y on the upper end surface 21e. The inlet 22 is closed by a closing member 23.

[0032] <modifier> The reformer 30 reforms methanol by a steam reforming reaction, a partial oxidation reaction, or a combination of a steam reforming reaction and a partial oxidation reaction, generating hydrogen gas as the reformed substance. When hydrogen gas is generated by a steam reforming reaction, the fuel cell system 10 has a tank for storing water and a heat source to promote the reaction. Since the partial oxidation reaction is an exothermic reaction, the reforming proceeds naturally. In this embodiment, the reformer 30 reforms methanol by a partial oxidation reaction. The reformer 30 reforms methanol supplied from the storage tank 20 and supplies the hydrogen gas generated by the reforming as fuel gas to the fuel cell stack 12.

[0033] <Relationship between fuel cell stack, oxidant gas supply unit, and reformer> As shown in Figure 4, an air cleaner 13a is connected to the oxidant gas supply unit 13. The oxidant gas supply unit 13 draws in air through the air cleaner 13a. The oxidant gas supply unit 13 is connected to the fuel cell stack 12 by an oxidant gas supply pipe 31. The air compressed by the oxidant gas supply unit 13 is supplied to a cathode (not shown) of the fuel cell stack 12 through the oxidant gas supply pipe 31. The reformer 30 is connected to the storage tank 20 by a connecting pipe 32. Methanol stored in the storage tank 20 is supplied to the reformer 30 through the connecting pipe 32. The reformer 30 is connected to the fuel cell stack 12 by a fuel gas supply pipe 33. The hydrogen gas generated in the reformer 30 is supplied to a cathode (not shown) of the fuel cell stack 12 through the fuel gas supply pipe 33. The fuel cell stack 12 generates electricity through the reaction of hydrogen gas and air.

[0034] <Containment> As shown in Figures 1 and 5, the housing 40 houses the fuel cell unit 11, the storage tank 20, and the reformer 30. The housing 40 has a box-shaped housing body 41 that opens to the front in the depth direction Y, and a door 42 that opens and closes the front of the housing body 41. Inside the housing body 41 are a first partition wall 51 and a second partition wall 52. The first partition wall 51 extends over the entire vertical direction Z of the housing body 41 and is positioned at an intermediate position in the horizontal direction X. The second partition wall 52 divides one side of the internal space S separated by the first partition wall 51 into two spaces in the vertical direction Z.

[0035] The internal space S is divided into a tank housing space S1, a unit housing space S2, and a reformer housing space S3. The tank housing space S1 is one of two spaces separated horizontally X by the first partition wall 51. The unit housing space S2 is a space different from the tank housing space S1 and is located below the second partition wall 52. The reformer housing space S3 is a space different from the tank housing space S1 and is located above the second partition wall 52.

[0036] The tank housing space S1, the unit housing space S2, and the reformer housing space S3 are adjacent to each other in the horizontal direction X, separated by the first partition wall 51. The unit housing space S2 and the reformer housing space S3 are adjacent to each other in the vertical direction Z, separated by the second partition wall 52. The door 42 opens and closes the tank housing space S1, the unit housing space S2, and the reformer housing space S3.

[0037] The storage tank 20 is housed in the tank housing space S1. The fuel cell unit 11 is housed in the unit housing space S2. The ventilation opening 16h of the fuel cell unit 11 opens toward the front of the housing body 41. The reformer 30 is placed on the upper surface of the second partition wall 52 and is housed in the reformer housing space S3. Therefore, the storage tank 20, the fuel cell unit 11, and the reformer 30 are housed in the housing body 40. The fuel cell unit 11 and the storage tank 20 are arranged adjacent to each other in the horizontal direction X, with the first partition wall 51 in between. In other words, the fuel cell unit 11 and the storage tank 20 are arranged side by side in the horizontal direction X. Also, the fuel cell unit 11 and the reformer 30 are arranged adjacent to each other in the vertical direction Z, with the second partition wall 52 in between. In other words, the fuel cell unit 11 and the reformer 30 are arranged side by side in the vertical direction Z. Furthermore, the reformer 30 is located above the fuel cell unit 11 in the vertical direction Z, while the air cleaner 13a is located below the reformer 30 in the vertical direction Z.

[0038] <Positional relationship between the inlet and the air cleaner> The centerline L of the fuel cell system 10 is defined as the line that divides the storage tank 20 into an upper and lower half in the vertical direction Z. The fuel cell unit 11 is located below the centerline L. Furthermore, the fuel cell unit 11 has an air cleaner 13a of the oxidizer gas supply unit 13. Therefore, the air cleaner 13a is located below the centerline L. The reformer 30 is located above the centerline L.

[0039] The inlet 22 is located on the upper end surface 21e of the tank body 21. Therefore, the inlet 22 is located above the center line L. As described above, the air cleaner 13a is located below the center line L. Therefore, the air cleaner 13a is located below the inlet 22.

[0040] The inlet 22 is positioned on the upper end surface 21e so as to be aligned with the first side surface 21a of the tank body 21. Therefore, the inlet 22 is positioned on the upper end surface 21e at a location that maximizes its distance from the air cleaner 13a in the horizontal direction X.

[0041] [Operation of the first embodiment] Next, we will explain the operation of the fuel cell system 10. When liquid methanol is introduced into the tank body 21 from the inlet 22, some of the methanol vaporizes. More specifically, liquid methanol vaporizes at room temperature, so it can be said to volatilize. Hereafter, the volatilized methanol will be simply referred to as "volatile methanol." Volatilized methanol is an example of a vaporized substance. Volatilized methanol remains around the inlet 22. Here, the air cleaner 13a is located below the inlet 22. Therefore, the amount of volatile methanol remaining around the air cleaner 13a is less than the amount of volatile methanol remaining around the inlet 22.

[0042] Subsequently, when the fuel cell system 10 is driven and the oxidizer gas supply unit 13 is driven, the air surrounding the oxidizer gas supply unit 13 is drawn into the oxidizer gas supply unit 13 through the air cleaner 13a and is also supplied to the fuel cell stack 12 as oxidizer gas.

[0043] At this time, the amount of volatile methanol remaining around the air cleaner 13a is less than the amount of volatile methanol remaining around the inlet 22. Therefore, the amount of volatile methanol drawn into the oxidizer gas supply unit 13 through the air cleaner 13a can be suppressed. As a result, the amount of volatile methanol drawn into the fuel cell stack 12 can be suppressed.

[0044] [Effects of the first embodiment] According to the first embodiment described above, the following effects can be obtained. (1-1) The air cleaner 13a is located below the inlet 22. In other words, the inlet 22 is located above the air cleaner 13a. Therefore, the amount of volatile methanol remaining around the air cleaner 13a, and consequently around the fuel cell stack 12, is less than the amount of volatile methanol remaining around the inlet 22. As a result, the effect of volatile methanol on the fuel cell stack 12 can be suppressed.

[0045] Furthermore, since the amount of volatile methanol drawn into the oxidizer gas supply unit 13 through the air cleaner 13a can be reduced, the amount of volatile methanol drawn into the fuel cell stack 12 can be reduced. As a result, deterioration of the fuel cell stack 12 due to volatile methanol is suppressed.

[0046] (1-2) The inlet 22 is located on the upper end surface 21e along the first side surface 21a. In other words, the inlet 22 is located on the upper end surface 21e at a position that increases the distance from the air cleaner 13a in the horizontal direction X. Therefore, it is possible to make it difficult for volatile methanol to spread to the area around the air cleaner 13a. As a result, the amount of volatile methanol drawn into the oxidizer gas supply unit 13 through the air cleaner 13a can be reduced. Furthermore, the effect of volatile methanol on the fuel cell stack 12 can be further reduced.

[0047] (1-3) The inlet 22 is located on the upper end surface 21e of the tank body 21. In other words, the inlet 22 is located at a position along the outer surface of the tank body 21 that maximizes the distance from the air cleaner 13a in the vertical direction Z. Therefore, volatile methanol is less likely to spread to the area around the air cleaner 13a. As a result, the amount of volatile methanol drawn into the oxidizer gas supply unit 13 through the air cleaner 13a can be reduced. Furthermore, the effect of volatile methanol on the fuel cell stack 12 can be further reduced.

[0048] (1-4) In the vertical direction Z, the reformer 30 is located above the fuel cell unit 11. Therefore, the reformer 30 acts as a physical shield between the inlet 22 and the air cleaner 13a. As a result, the reformer 30 makes it difficult for volatile methanol to spread around the air cleaner 13a. Consequently, the amount of volatile methanol drawn into the oxidizer gas supply unit 13 through the air cleaner 13a can be reduced.

[0049] (1-5) The reformer 30 is placed on the upper surface of the second partition wall 52. The reformer 30 generates heat when reforming methanol. The heat generated in the reformer 30 is transferred to the second partition wall 52. As a result, the heat generated in the reformer 30 is less likely to be transferred to the fuel cell stack 12 of the fuel cell unit 11.

[0050] (1-6) A second partition wall 52 is interposed between the reformer 30 and the fuel cell unit 11. The second partition wall 52 acts as a physical barrier between the inlet 22 and the air cleaner 13a. As a result, the second partition wall 52 makes it difficult for volatile methanol to spread around the air cleaner 13a. Consequently, the amount of volatile methanol drawn into the oxidizer gas supply unit 13 through the air cleaner 13a can be reduced.

[0051] [Second Embodiment] Next, a second embodiment of the fuel cell system 10 will be described with reference to Figures 6 and 7. Since the second embodiment only differs in the position of the input port 22, a detailed explanation of the similar parts will be omitted.

[0052] As shown in Figures 6 and 7, the fourth side surface 21d of the tank body 21 is located behind the heat exchanger 14 of the fuel cell unit 11 in the depth direction Y. Furthermore, the fourth side surface 21d is located behind the outer surface of the fourth side wall 16g of the housing 16 in the depth direction Y. The inlet 22 is located on the fourth side surface 21d of the tank body 21. Therefore, the inlet 22 is located behind the fan 15 and the heat exchanger 14 in the depth direction Y.

[0053] As described above, the airflow direction F generated by the fan 15 is from the vent 16h toward the heat exchanger 14. Also, the airflow direction F is from the third side wall 16f toward the fourth side wall 16g in the depth direction Y.

[0054] Furthermore, the inlet 22 is located behind the outer surface of the fourth side wall 16g in the depth direction Y. Therefore, in the airflow direction F, the inlet 22 is located downstream of the air cleaner 13a and also downstream of the fan 15.

[0055] [Effects of the second embodiment] According to the second embodiment described above, in addition to the effects described in (1-4), (1-5), and (1-6) of the first embodiment, the following effects can be obtained.

[0056] (2-1) Since the inlet 22 is located downstream of the fan 15 in the airflow direction F, volatile methanol remaining around the inlet 22 is blown downstream of the fan 15. Therefore, the amount of volatile methanol remaining around the air cleaner 13a is less than the amount of volatile methanol remaining around the inlet 22. As a result, the effect of volatile methanol on the fuel cell stack 12 can be suppressed. Furthermore, since the amount of volatile methanol drawn into the oxidizer gas supply unit 13 through the air cleaner 13a can be suppressed, the amount of volatile methanol drawn into the fuel cell stack 12 can be suppressed. As a result, deterioration of the fuel cell stack 12 due to volatile methanol is suppressed.

[0057] This embodiment can be implemented with the following modifications. This embodiment and the following modifications can be combined with each other to the extent that they do not contradict each other technically. As shown in Figure 8, the inlet 22 and the air cleaner 13a may be located on opposite sides of each other in the horizontal direction X, with the fuel cell unit 11 and the storage tank 20 in between.

[0058] With this configuration, the horizontal distance X between the air cleaner 13a and the inlet 22 can be increased. As a result, the amount of volatile methanol drawn into the oxidizer gas supply unit 13 and the fuel cell stack 12 through the air cleaner 13a can be further reduced.

[0059] As shown in Figure 9, the inlet 22 may be connected to the outside of the housing 40 by a connecting pipe 43. This makes it difficult for volatile methanol to enter the inside of the housing 40. As a result, the amount of volatile methanol remaining around the air cleaner 13a is less than the amount of volatile methanol remaining around the inlet 22. Consequently, the effect of volatile methanol on the fuel cell stack 12 can be suppressed. Furthermore, since the amount of volatile methanol drawn into the oxidizer gas supply unit 13 through the air cleaner 13a can be suppressed, the amount of volatile methanol drawn into the inside of the fuel cell stack 12 can be suppressed. Thus, deterioration of the fuel cell stack 12 due to volatile methanol is suppressed.

[0060] ○The fuel cell unit 11 and the reformer 30 do not have to be aligned in the vertical direction Z. For example, the storage tank 20, the fuel cell unit 11, and the reformer 30 may be aligned in the horizontal direction X. In this case, the fuel cell unit 11 is positioned between the storage tank 20 and the reformer 30. Even in this case, the inlet 22 is located above the center line L, and the air cleaner 13a is located below the center line L. Alternatively, in the air flow direction F, the inlet 22 is located downstream of the air cleaner 13a.

[0061] ○The fuel cell unit 11, the storage tank 20, and the reformer 30 do not necessarily have to be housed in the containment body 40. ○In the first embodiment, as long as the inlet 22 is located above the center line L, the inlet 22 may be located on any of the first side surface 21a, the third side surface 21c, or the fourth side surface 21d of the tank body 21.

[0062] ○In the first embodiment, the position of the input opening 22 on the upper end surface 21e may be changed as desired. ○In the first embodiment, as long as the air cleaner 13a is located below the center line L, the air cleaner 13a may be located anywhere within the housing 16. For example, the air cleaner 13a may be located near the third side wall 16f and also near the second side wall 16e.

[0063] ○In the second embodiment, the position of the inlet 22 on the fourth side surface 21d can be arbitrarily changed as long as the inlet 22 is located downstream of the fan 15 in the airflow direction F, but it is preferable that it be above the center line L.

[0064] ○In the second embodiment, the unit housing space S2 and the reformer housing space S3 of the housing 40 may be swapped vertically. The reformer 30 may also be placed below the fuel cell unit 11.

[0065] ○In each embodiment, the air cleaner 13a may be omitted. In this case, the intake port of the oxidizer gas supply unit 13 becomes the intake port of the air compressor. ○The fuel cell system 10 of the first embodiment does not necessarily have a heat exchanger 14 and a fan 15. In this case, the fuel cell system 10 only has a fuel cell unit 11, a storage tank 20 and a reformer 30.

[0066] ○In each embodiment, the oxidant gas supply unit 13 does not have to be an air compressor that compresses and supplies air. In other words, the oxidant gas supply unit 13 may be a pump that simply transfers air without compressing it.

[0067] ○The stored material in storage tank 20 may be volatile organic compounds other than methanol, such as ethanol, butanol, or propanol, or it may be ammonia. The stored material in storage tank 20 may also be a liquid that vaporizes at atmospheric pressure.

[0068] ○The fuel cell system 10 may also be for use in vehicles. The technical concepts that can be understood from the above embodiments and modified examples are described below. The fuel cell system, wherein the input port is connected to the outside of the housing by a connecting pipe. [Explanation of Symbols]

[0069] L...centerline, 10...fuel cell system, 11...fuel cell unit, 12...fuel cell stack, 13a...air cleaner as air intake, 13...oxidizer gas supply unit, 14...heat exchanger, 15...fan, 20...storage tank, 21...tank body, 22...inlet, 30...reformer, 40...container.

Claims

1. A fuel cell unit having a fuel cell stack and an oxidant gas supply unit that supplies air drawn in through an air intake as an oxidant gas to the fuel cell stack, A storage tank is arranged horizontally alongside the fuel cell unit and has a tank body for storing fuel gas raw materials in liquid form, and has an inlet for introducing the raw materials into the tank body. A fuel cell system having a reformer that supplies a reformed substance, produced by reforming the raw material supplied from the storage tank, to the fuel cell stack as the fuel gas, If the line dividing the storage tank into an upper and lower half in the vertical direction is defined as the centerline of the fuel cell system, The aforementioned input opening is located above the center line, The aforementioned air intake is located below the center line. A fuel cell system characterized in that the fuel cell unit and the storage tank are arranged adjacent to each other in the horizontal direction, and the inlet and the air intake are located on opposite sides of each other in the horizontal direction, with the fuel cell unit and the storage tank in between.

2. A fuel cell unit having a fuel cell stack and an oxidant gas supply unit that supplies air drawn in through an air intake as an oxidant gas to the fuel cell stack, A storage tank is arranged horizontally alongside the fuel cell unit and has a tank body for storing fuel gas raw materials in liquid form, and has an inlet for introducing the raw materials into the tank body. A fuel cell system having a reformer that supplies a reformed substance, produced by reforming the raw material supplied from the storage tank, to the fuel cell stack as the fuel gas, If the line dividing the storage tank into an upper and lower half in the vertical direction is defined as the centerline of the fuel cell system, The aforementioned input opening is located above the center line, The aforementioned air intake is located below the center line. A fuel cell system characterized in that the storage tank, the fuel cell unit, and the reformer are housed in a housing, and in the vertical direction, the reformer is located above the fuel cell unit in the vertical direction, and the air intake is located below the reformer in the vertical direction.

3. A fuel cell unit having an oxidizer gas supply unit that supplies air drawn in through an air intake as an oxidizer gas to the fuel cell stack, a heat exchanger that exchanges heat between outside air and a heat exchange medium, and a fan that blows air toward the heat exchanger, and cooling the fuel cell stack by cooling the heat exchange medium with the air blown by the fan, A storage tank is arranged horizontally alongside the fuel cell unit and has a tank body for storing fuel gas raw materials in liquid form, and has an inlet for introducing the raw materials into the tank body. A fuel cell system having a reformer that supplies a reformed substance, produced by reforming the raw material supplied from the storage tank, to the fuel cell stack as the fuel gas, A fuel cell system characterized in that the direction of airflow generated by the fan is from the inside to the outside of the fuel cell unit, and the inlet is located downstream of the fan in the direction of airflow.

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