TWI748920B - Fuel cell module and fuel cell system - Google Patents

Abstract

The fuel cell module (22, 39) includes a plurality of fuel cell cells (1, 29, 40) and at least one distribution plate (13, 33, 44). Each fuel cell (1, 29, 40) has at least one power generation element (7). The power generation element (7) includes an electrolyte layer (5), and a first electrode (4) and a second electrode (6) sandwiching the electrolyte layer (5). The distribution plates (13, 33, 44) define a passage for at least one of fuel gas or oxidant gas supplied to the first electrode (4) and the second electrode (6). The distribution plate (13, 33, 44) has a first surface and a second surface, and has a first through hole (16) or a supply side flow channel (45) of the distribution plate penetrating from the first surface to the second surface. The first through hole (16) of the distribution plate or the supply side flow channel (45) divides the passage to the first surface and the second surface.

Description

Fuel cell module and fuel cell system

The present invention relates to a fuel cell module and a fuel cell system.

Patent Document 1 describes the use of a separator having grooves in a fuel cell. For example, in paragraph [0057] it is stated that "100 such cell plates are used. As shown in Figure 11, they are laminated with a plate thickness of 0.5mm and a groove depth of 0.2mm each sandwiched by a separator plate to produce When fuel cells are stacked, the height becomes 100.5mm.”

Patent Document 2 describes that fuel cells are stacked upside down. For example, in paragraph [0025], it is stated that "Other embodiments regarding the lamination of microelectromechanical systems (MEMS) fuel cells are shown in FIG. 8. In this embodiment, the substrate/main structure 211' has fuel cell electrodes/electrolytes The stack 213, single or plural openings, grooves or holes 220 are combined with the same substrate/main structure 211 at the interface 219, or mechanically sealed. These are arranged upside down to form the symmetrical structure shown in Fig. 8 , A single fuel introduction part 215 supplies fuel to an area twice the effective area of the fuel cell stack.". [Prior Technical Literature] [Patent Literature]

[Patent Document 1] JP 2004-206998 A [Patent Document 2] Japanese Special Publication No. 2005-532661

[The problem to be solved by the invention]

However, the problem of the previous technology is that it is difficult to improve the gas supply efficiency and to ensure the mechanical strength.

In Patent Document 1, since the grooves of the separator are straight, the gas flow becomes laminar, and there is a problem that the amount of gas flowing into the opening is reduced, or the removal of consumed gas is small. Therefore, it is necessary to increase the gas flow rate, but if the gas flow rate increases, the membrane electrolyte in the opening may be affected and damaged. In addition, a large amount of gas is circulated and it cannot be consumed efficiently, and a large amount of residual gas that does not contribute to power generation is discharged, which becomes an important cause of cost increase.

In Patent Document 2, when a plurality of fuel cell laminates are arranged on the surface of the substrate, it is necessary to provide a plurality of through holes from the surface of the substrate to the back surface, which increases the processing area of the back surface. Therefore, the mechanical strength of the substrate itself is reduced. In addition, flatness is impaired on the back side of the substrate. That is, when the back surfaces of the fuel cell cells are bonded, insufficient bonding may occur, and the bonded fuel cell cells may peel off, or there may be a problem of gas leakage.

The present invention is an invention made to solve such a problem, and its object is to provide a fuel cell module and a fuel cell system that can improve the efficiency of gas supply while ensuring mechanical strength. [Means for problem solving]

An example of the fuel cell module related to the present invention, Equipped with: multiple fuel cell cells, and at least one valve plate; Each of the foregoing fuel cell cells has at least one power generation element; The aforementioned power generating element includes: an electrolyte layer, and two electrode layers sandwiching the aforementioned electrolyte layer; The aforementioned valve plate defines a passage for at least one of the fuel gas or the oxidant gas supplied to the aforementioned electrode layer; The aforementioned distribution plate has a first side and a second side; The aforementioned valve plate has a through hole penetrating from the first surface to the second surface; The through hole diverges the passage to the first surface and the second surface.

In addition, an example of the fuel cell system related to the present invention includes: The aforementioned fuel cell module, and A housing for controlling the temperature of the aforementioned fuel cell module. [Effects of the invention]

According to the fuel cell module and the fuel cell system related to the present invention, the gas supply efficiency can be improved and the mechanical strength can be ensured.

The problems, configurations, and effects other than the foregoing can be clarified by the description of the modes for implementing the following invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. The embodiments are merely examples for explaining the present invention, and for clarification of the description, they are omitted and simplified as appropriate. The present invention can also be implemented in various other forms. As long as there is no particular limitation, each component may be singular or plural.

In order to make it easier to understand the invention, the positions, sizes, shapes, and ranges of each component shown in the drawings may not show the actual positions, sizes, shapes, and ranges. Therefore, the present invention is not necessarily limited to the position, size, shape, range, etc. disclosed in the drawings.

When there are multiple components with the same or equivalent functions, there are cases where different subscripts are assigned to the same symbol for explanation. In addition, when there is no need to distinguish between these plural components, the subscripts may be omitted and the description may be omitted.

The present invention relates to a fuel cell module and a fuel cell system. In recent years, fuel cells have attracted attention as a clean energy source that can perform high-energy conversion and does not emit pollutants such as carbon dioxide or nitrogen oxides. Among the fuel cells, a solid electrolyte fuel cell (Solid Oxide Fuel Cell, hereinafter referred to as SOFC) has high power generation efficiency and can use easy-to-handle gases such as hydrogen, methane, and carbon monoxide as fuel. In this way, SOFC has many advantages compared with other methods, and it is expected as a thermoelectric symbiosis system with excellent energy saving and environmental performance.

SOFC is a structure in which a solid electrolyte is sandwiched between a fuel electrode and an air electrode. The electrolyte is the partition wall, and fuel gas such as hydrogen is supplied to the fuel electrode side, and oxidant gas such as air is supplied to the air electrode. In particular, silicon SOFC has many advantages such as high-efficiency power generation, low-temperature operation, and light weight, so it is very promising.

In the following, air is used as a representative oxidant gas, but gases other than air may also be used as the oxidant gas.

In addition, in the following figures, in order to make it easier to understand, there are some cases where hatching is added to the non-cross-sectional part. <Implementation Type 1> Fig. 1 is a plan view of a fuel cell 1 related to Embodiment 1 of the present invention. Fig. 2 is a cross-sectional view taken along the line A-A in Fig. 1. For the convenience of description, the up and down direction on the paper in FIG. 2 is taken as the up and down direction of the fuel cell 1, but this direction has nothing to do with the direction in which the fuel cell is actually installed or used.

The fuel cell 1 includes a semiconductor substrate 2 made of single crystal silicon (Si), and a first insulating film 3 formed on the semiconductor substrate 2. A part of the upper surface of the first insulating film 3 is covered by the first electrode 4. The upper surface of the first electrode 4 is covered by the electrolyte layer 5, but a part of the first electrode 4 is exposed. A second electrode 6 is formed on the upper side of the first electrode 4 and the electrolyte membrane 5.

The fuel cell 1 has a plurality of first openings 8 and one second opening 9. These openings are provided through the semiconductor substrate 2 and the first insulating film 3. The first opening 8 is hidden from view by the first electrode 4 and the second electrode 6 when viewed from above. The plan view in Fig. 1 is indicated by a dashed line.

The first opening 8 is, for example, a rectangular shape in a plan view, and the length of one side is approximately 0.2 mm to 5 mm. A plurality of first openings 8 are arranged in the semiconductor substrate 2. The second opening 9 is, for example, a rectangular shape in a plan view, and the length of one side is approximately 0.5 μm to 1 mm. In addition, as a modified example, the second opening 9 may be formed with a plurality of small-area openings. In addition, the shapes of the first opening 8 and the second opening 9 are not limited to those shown in the drawings, and may be circular or polygonal, for example.

As shown in FIG. 2, a first insulating film 3 is formed on the semiconductor substrate 2. Part of the inner region of the semiconductor substrate 2 and the first insulating film 3 is removed, and the first opening 8 and the second opening 9 are formed. The first opening 8 is formed in plural.

The fuel cell 1 includes at least one power generation element 7. The film structure of the power generating element 7 is formed so as to cover the plurality of first openings 8. The membrane structure is a laminate in which the first electrode 4 (electrode layer), the electrolyte membrane 5, and the second electrode 6 (electrode layer) are sequentially formed from the bottom. In this way, the power generation element 7 includes an electrolyte layer 5 and two electrode layers sandwiching the electrolyte layer 5. These two electrode layers are electrode layers in contact with gas, and are also called gas electrode layers.

Moreover, this power generating element 7 partitions the space above and below the first opening 8 by covering the plurality of first openings 8. In this way, the upper and lower gases are shielded in a way that they do not mix.

In this regard, the second opening 9 is a through hole for passing gas. That is, the gas may flow from the upper surface side to the lower surface side of the second opening 9 or in the opposite direction.

The semiconductor substrate 2 is, for example, a silicon substrate composed of a crystal orientation of <100>, and has a thickness of 400 μm or more. The first opening 8 and the second opening 9 are patterned on the lower surface side by a photoetching method, and then a part is removed by dry etching or wet etching. Dry etching can be performed with a fluorine-based gas. Wet etching can be performed with KOH (potassium hydroxide) solution or TMAH (tetramethyl amide) solution.

That is, on the lower surface side of the first opening 8, the first electrode 4 is exposed. In addition, one of the first electrode 4 and the second electrode 6 of the power generating element 7 serves as an anode electrode and the other serves as a cathode electrode, and each is connected to the outside. Thereby, the fuel cell 1 generates electricity and supplies the electric power to the outside.

FIG. 3 is a plan view of the cushioning material 10 related to Embodiment 1 of the present invention. Fig. 4 is a cross-sectional view taken along the line A-A in Fig. 3. The outer dimensions of the buffer material 10 are the same as the fuel cell 1 or slightly larger.

The buffer material 10 has a plurality of first through holes 11 and one second through hole 12. When viewed from above, the opening area of the first through hole 11 is larger than the opening area of the second through hole 12. The fuel cell 1 and the buffer material 10 are arranged one above the other. One first through hole 11 communicates with a plurality of first openings 8. The first through hole 11 is arranged so as not to block even a part of the first opening 8. The second through hole 12 is provided in almost the same area as the second opening 9 of the fuel cell 1.

The first through hole 11 and the second through hole 12 define a passage for fuel gas or air supplied to the first electrode 4 or the second electrode 6.

The buffer material 10 preferably has heat resistance of 500°C or higher. In addition, when pressure is applied from the up and down direction, the cushioning material 10 is suitable to deform along the compressed shape. In this way, the pressure applied to the fuel cell 1 is alleviated.

Moreover, the thickness of the buffer material 10 is 1 mm or less, for example. In addition, in the present embodiment, a plurality of first through holes 11 are provided so as to avoid the central part of the buffer material 10, so the lower pillar (thick area) remains in the central part of the buffer material 10, and the mechanical strength can be maintained.

Fig. 5 is a plan view of the distribution plate 13 related to the first embodiment of the present invention. Fig. 6 is a cross-sectional view taken along the line A-A in Fig. 5. Fig. 7 is a cross-sectional view taken along the line B-B in Fig. 5. In Fig. 5, different shadows are given to surfaces with different heights (positions in the vertical direction).

Inside the distribution plate 13, an upper flow passage 14, a lower flow passage 15, and a first through hole 16 of the distribution plate are formed. The distribution plate 13 has an upper surface (first surface) and a lower surface (second surface), and the first through hole 16 of the distribution plate penetrates the distribution plate 13 from the upper surface to the lower surface.

In addition, the first through hole 16 of the valve plate is connected to communicate with a part of the upper flow passage 14 and a part of the lower flow passage 15. Here, the first through hole 16 of the distributor plate may be a flow channel composed of an upper flow channel 14, a lower flow channel 15, and a flow channel connecting the upper flow channel 14 and the lower flow channel 15.

The outer dimensions of the distribution plate 13 are almost the same as those of the fuel cell 1. In addition, the upper flow passage 14, the lower flow passage 15, and the first through hole 16 of the distributor plate are arranged so that the gas diffuses in the horizontal direction.

In the cross section shown in FIG. 6, both the upper flow passage 14 and the lower flow passage 15 are formed in a partial area, and these are connected as the first through hole 16 of the valve plate. On the other hand, in the cross section shown in FIG. 7, the area where only the upper flow passage 14 is formed and the area where only the lower flow passage 15 is formed are alternately arranged. In addition, in the cross section shown in FIG. 7, there are columns (thick areas) in which neither the upper flow passage 14 nor the lower flow passage 15 are arranged.

With such a configuration of the distribution plate 13, the gas reaching the distribution plate 13 circulates in the plane direction and the vertical direction in three dimensions within the distribution plate 13. At this time, the upper flow passage 14, the lower flow passage 15, and the first through hole 16 of the distributor plate are formed in a manner of gas dispersion or gathering (described later in detail with reference to FIG. 10, etc.).

In this way, the gas passage in the distribution plate 13 is configured as the first through-hole 16 of the distribution plate, so the distribution plate 13 itself becomes the peripheral wall of the through-hole, and the strength of the passage is high.

The distribution plate 13 is, for example, a silicon substrate composed of a crystal orientation of <100>, and has a thickness of about 400 μm. In addition, the upper flow channel 14 and the lower flow channel 15 and the first through hole 16 of the distribution plate are patterned by a photolithography method, and then a part is formed by removing a part by dry etching or wet etching. Dry etching can be performed with a fluorine-based gas. Wet etching can be performed with KOH (potassium hydroxide) solution or TMAH (tetramethyl amide) solution.

The silicon substrate has excellent heat conduction and is suitable for maintaining the temperature of the fuel cell module. In addition, ceramics can also be used for the distribution plate 13. That is, as shown in FIG. 5, the distribution plate 13 is made of silicon or ceramic.

When silicon is used for the distribution plate 13, the thermal expansion coefficient of the distribution plate 13 is the same as the thermal expansion coefficient of the semiconductor substrate 2, so that the strain of the fuel cell module accompanying temperature changes can be avoided. In addition, the thermal expansion coefficient of ceramics is close to that of silicon, so the same effect can be obtained when ceramics are used in the distribution plate 13.

FIG. 8 is a plan view of the supporting substrate 17 related to Embodiment 1 of the present invention. Fig. 9 is a cross-sectional view taken along the line A-A in Fig. 8. The supporting substrate 17 is formed with a groove 18 that becomes a flow path of fuel gas or air. In this embodiment, the groove 18 is a flow path for air. In the inside of the support substrate 17, a column 19 (thick area) which is in contact with the buffer material 10 is provided.

The supporting substrate 17 is provided with an air flow channel 20 and a fuel gas flow channel 21. The air flow passage 20 is open on the side surface, for example, and communicates with the groove 18. The fuel gas flow channel 21 is shielded from the groove 18 and opens on the side and upper surface of the support substrate 17. The outer dimension of the support substrate 17 may be larger than any of the fuel cell 1, the buffer material 10, and the distribution plate 13, for example.

The supporting substrate 17, which is related to FIG. 10 and is used in overlapping with the buffer material 10 as described later, supports the buffer material 10. At this time, if the buffer material 10 is reversed from the state shown in FIG. 3 (that is, rotated 180 degrees around the axis X in FIG. 3), the groove 18 of the substrate 17 and the first through hole of the buffer material 10 are supported 11 overlaps and communicates, and the fuel gas flow path 21 of the support substrate 17 and the second through hole 12 of the buffer material 10 overlap and communicate with each other.

FIG. 10 is a cross-sectional view of a fuel cell module 22 related to Embodiment 1 of the present invention. As shown in FIG. 10, the fuel cell module 22 includes a plurality of fuel cell cells 1 (1a, 1b) and at least one valve plate (in the example of FIG. 10, one valve plate 13). In addition, the fuel cell module 22 includes buffer materials 10 (10a, 10b, 10c, 10d) arranged between the fuel cell cells 1a, 1b and the distribution plate 13, respectively. In addition, the fuel cell module 22 includes support substrates 17 (17a, 17b) that support the cushioning materials 10a, 10d from the outside in the vertical direction, respectively. In addition, the buffer material and the supporting substrate are not essential, and some or all of these may be omitted.

The fuel cell module 22 is constituted by stacking the following components in order from the bottom, for example. ‐Support substrate 17(17b) -Buffer material 10 (10d) reversed left and right (that is, rotated 180 degrees around the axis X in Figure 3) -Fuel cell 1 (1b) reversed left and right (that is, rotated 180 degrees around the axis X in Figure 1) -Buffer material 10 (10c) reversed left and right (that is, rotated 180 degrees around the axis X in Figure 3) ‐Distribution plate 13 ‐Buffer material 10(10b) ‐Fuel cell cell 1 (1a) ‐Buffer material 10(10a) ‐Support base plate 17 (17a) that is reversed left and right (that is, rotated 180 degrees around the axis X in Figure 8)

In this way, in the fuel cell module 22, two fuel cell cells 1 are stacked.

In addition, a pressure 23 is applied to the supporting substrates 17a, 17b by a pressure mechanism not shown. Thereby, the buffer material 10 arranged between each layer is deformed, and the leakage of fuel gas and air is prevented. The air flow passage 20 and the fuel gas flow passage 21 of the supporting substrates 17a and 17b are connected to an external gas pipe, so that the fuel gas and air can be sent and exhausted.

Each buffer material 10 is in contact with at least one of the valve plate 13 and the fuel cell 1. With such a configuration, the influence on the pressure 23 of the valve plate 13 and the fuel cell 1 is alleviated. In addition, the buffer material 10 may have a structure that is not in contact with the distribution plate 13 and the fuel cell cell 1 (for example, another layer may be arranged between the buffer material 10, the distribution plate 13 and the fuel cell cell 1).

Next, the flow of fuel gas and air will be explained. The flow of each gas can be known from the arrow in Fig. 10 and the structure of each component shown in Figs. 1-9. It is only for reference and supplementary explanation as follows.

First, the fuel gas enters through the fuel gas flow channel 21 of the upper support substrate 17a, and sequentially passes through the second through hole 12 of the buffer material 10a, the second opening 9 of the fuel cell 1a, and the second through hole of the buffer material 10b. The hole 12 reaches the upper flow channel 14 of the distribution plate 13.

In this way, the fuel cell 1 defines a passage through which the fuel gas supplied to the first electrode 4 flows, and the distribution plate 13 defines a passage through which the fuel gas supplied to the first electrode 4 flows. The passage of the fuel cell 1 communicates with the passage of the valve plate 13 to form a common passage. In addition, as a modified example, this common passage may be a passage through which air circulates, or may be configured as a common passage for both fuel gas and air.

The fuel gas reaching the valve plate 13 is branched up and down through the upper flow passage 14 through the first through hole 16 of the valve plate. The fuel gas branched to the upper side passes through the first through hole 11 of the buffer material 10 b on the upper side of the distribution plate 13 and the plurality of first openings 8 of the upper fuel cell 1 a, and is supplied to the first electrode 4. Thereby, the power generating element 7 generates power.

The fuel gas branched to the lower side of the valve plate 13 passes through the first through hole 11 of the buffer material 10c on the lower side of the valve plate 13, and the plurality of first openings 8 of the lower fuel cell 1b, and is supplied to the first electrode 4. Thereby, the power generating element 7 generates power.

In this way, the valve plate 13 defines the passage of the fuel gas supplied to the first electrode 4. In addition, as a modified example, the valve plate 13 may define a passage for air, or may define a passage for both fuel gas and air.

The first through hole 16 of the valve plate divides the passage of the fuel gas upward and downward (that is, upper and lower sides). As a result, the fuel gas is dispersed up and down, and therefore it reaches the first opening 8 of the plurality of fuel cell cells 1 efficiently, and the power generation efficiency is improved.

The branched fuel gas passes through the buffer materials 10b and 10c and merges at the center of the distribution plate 13. The merged fuel gas is again branched up and down through the first through hole 16 of the valve plate 13 and supplied to the first electrode 4 of the other power generating element 7. Thereby, the other power generating element 7 generates power.

After that, the fuel gas passes through the first through hole 16 of the valve plate again and merges. The merged fuel gas sequentially passes through the second through hole 12 of the buffer material 10c, the second opening 9 of the fuel cell 1b, and the second through hole 12 of the buffer material 10d, and is exhausted from the lower support substrate 17b.

In this way, one distribution plate 13 defines a passage connected to the plurality of power generating elements 7. Thereby, the structure for forming the passage is simplified, and the space can be used efficiently.

Regarding the flow of air, the air entering from the air flow channel 20 of the upper supporting substrate 17a passes through the groove 18 of the supporting substrate 17a. The groove 18 is an opening that penetrates the first through hole 11 of the buffer material 10 a and opens toward the power generating element 7, so air is supplied to the second electrode 6 of the power generating element 7. In this way, air is efficiently supplied to the power generating element 7. In addition, as a modified example, the opening area of the groove 18 seen from above may be larger than the opening area of the first through hole 11 seen from above.

After that, the air passes through the groove 18 of the support substrate 17a, and is discharged to the outside from the other air flow channels 20 not shown in FIG. 10. The air in the groove 18 is branched at the column 19 and is efficiently supplied to the plurality of power generating elements 7.

The same applies to the support substrate 17b on the lower side. Moreover, in this embodiment, the shapes of the upper and lower support substrates 17a, 17b are the same, but these shapes may also be different. For example, the shape of the groove 18 may be different.

In this way, the fuel cell module 22 is provided with the distribution plate 13, so that the supply efficiency can be improved by dividing the gas while ensuring the mechanical strength.

In addition, since the passages formed in the distribution plate 13 are not linear, as in Patent Document 1, the flow of gas does not become laminar. Therefore, compared with the structure of Patent Document 1, the gas utilization efficiency becomes higher.

Furthermore, in the fuel cell 1, the number of the second openings 9 provided in the semiconductor substrate 2 is small (single one in the example of FIG. 1 ). Therefore, compared with the structure shown in FIG. 8 of Patent Document 2, the high mechanical strength of the substrate itself can be maintained.

FIG. 11 shows a schematic diagram of a fuel cell system related to Embodiment 1. FIG. The main components of the fuel cell system include: a blower 24 for sending out fuel gas and air, a reformer 25 with a fuel gas flow adjustment mechanism, a pressure regulator 26 for adjusting the pressure of the air, and a temperature control for the fuel cell module 22 The casing 27 for this and the combustor 28 that burns the exhausted fuel gas.

The casing 27 is controlled so as to maintain the temperature of the fuel cell module 22 at a constant temperature, for example. This certain temperature is, for example, in the range of 300°C to 600°C. Thereby, the fuel cell module 22 operates efficiently and stably.

For example, methane can be used as the fuel gas. The methane is blown by the blower 24, and the flow rate and pressure are adjusted in the reformer 25. In this way, a fuel gas of about 600° C. containing hydrogen is generated. The fuel gas is sent to the fuel cell module 22.

In addition, the air is also sent by the blower 24, the pressure and flow are adjusted by the pressure regulator 26, and then sent to the fuel cell module 22. In addition, the temperature of the air is about 600°C by using the heat of the reformer 25.

The flow rate of fuel gas and air must be increased to several liters per minute at the maximum output, for example.

The reformed fuel gas and heated air are sent to the fuel cell module 22 through the piping and held in the housing 27 at about 500° C., where they are consumed for power generation. The fuel gas and air discharged from the fuel cell module 22 are merged by the combustor 28 and burned at a high temperature, and then discharged.

In addition, the exhaust heat of the combustor 28 may be used to heat the gas piping before entering the fuel cell module 22.

Although not shown, it is also possible to perform feedback control of pressure and flow rate for fuel gas and air. For example, a pressure gauge and a flow meter can be installed in each gas piping, and the pressure and flow rate of the reformer 25 and the pressure and flow rate of the pressure regulator 26 can be compared, and feedback control can be performed at the same time to adjust the pressure and flow rate in each gas piping.

In Embodiment 1, methane is mentioned as the fuel gas, but it is not particularly limited as long as it is a gas that can be upgraded. For example, as the hydrocarbon fuel, natural gas, LP gas (liquefied petroleum gas), coal-modified gas, lower hydrocarbon gas (ethane, ethylene, propane, butane), biomass ethanol, etc. can be used. In addition, a vaporizer may be provided at the front stage of the reformer 25, and the vaporizer may vaporize the moisture from the raw material gas (or liquid) of the hydrocarbon fuel.

The fuel cell module 22 is an example in which the fuel cell 1 is overlapped up and down, but it may be arranged in a horizontal direction. In this case, the gas can be circulated from bottom to top.

In addition, as shown in FIG. 2, the fuel cell 1 may be provided with a sensor. The sensor can be configured in place of one of the power generating elements 7. The sensor detects at least one of the failure, temperature, humidity, and pressure of the fuel cell cell 1. According to such a configuration, the fuel cell 1 and the fuel cell module 22 can be operated more stably.

<Implementation Type 2> The second embodiment is related to the fuel cell module that makes the number of stacks of fuel cell and distribution plate more than that of the first embodiment, which can achieve a higher output power generation fuel cell module.

Fig. 12 is a plan view of a fuel cell 29 related to Embodiment 2 of the present invention. The configuration of the first insulating film 3, the power generation element 7, the plurality of first openings 8, and the second openings 9 of the fuel cell 29 is the same as that of the fuel cell 1 of the first embodiment.

The difference from the first embodiment is that the fuel cell 29 is provided with a third opening 30. The third opening 30 penetrates the semiconductor substrate 2 up and down like the second opening 9. The third opening 30 is, for example, rectangular, and the length of one side is approximately 0.5 μm to 1 mm. In addition, the third opening 30 may be a small-diameter opening, or may be formed in plural.

FIG. 13 is a plan view of the cushioning material 31 related to Embodiment 2 of the present invention. The first through hole 11 and the second through hole 12 of the buffer material 31 are the same as the buffer material 10 of the first embodiment.

The difference from the first embodiment is that the buffer material 31 is provided with a third through hole 32. When the buffer material 31 and the fuel cell 29 are overlapped, the third through hole 32 of the buffer material 31 and the third opening 30 of the fuel cell 29 overlap and communicate with each other.

The outer dimension of the buffer material 31 may be the same as that of the fuel cell 29, or may be a slightly larger size. In addition, as in the first embodiment, a plurality of first through holes 11 are provided so as to avoid the central part of the buffer material 31, so the lower pillar (thick area) remains in the central part of the buffer material 31, and the mechanical strength can be maintained.

14 is a plan view and a cross-sectional view of the distribution plate 33 related to the second embodiment of the present invention. The cross-sectional view is a cross-sectional view along the line C-C of the plan view. Similar to the first embodiment, the distribution plate 33 is provided with an upper flow passage 14, a lower flow passage 15, and a first through hole 16 of the distribution plate.

The difference from the first embodiment is that the second through hole 34 of the distribution plate, the gas discharge flow passage 35 and the gas flow passage 36 for rotation are provided. When the distribution plate 33 and the cushioning material 31 are overlapped in an appropriate direction and position, the distribution plate second through hole 34 of the distribution plate 33 and the third through hole 32 of the cushioning material 31 overlap and communicate with each other.

The gas discharge flow passage 35 has a through hole that penetrates the flow distribution plate 33 up and down, and communicates with the upper flow passage 14 and the lower flow passage 15. When the cushioning material 31 is overlapped on the lower side of the distribution plate 33, the second through hole 12 of the cushioning material 31 communicates with the gas discharge flow passage 35 of the distribution plate 33 to allow gas to be discharged.

The gas flow path is divided into the upper and lower directions on the paper in the plan view of Fig. 14. For example, in the plan view of FIG. 14, the gas enters from the left side of the paper surface, the gas flows on the upper side of the paper surface, and reaches the lower side of the paper surface through the gas flow channel 36 for rotation. Then, the gas flows on the lower side of the paper surface and flows into the gas discharge flow channel 35. The outer dimensions of the distribution plate 33 are almost the same as those of the fuel cell 29.

FIG. 15 is a plan view of the supporting substrate 37 related to the second embodiment of the present invention. As for the supporting substrate 37, the groove 18, the pillar 19, and the fuel gas flow channel 21 are the same as the supporting substrate 17 of the first embodiment.

The difference from the first embodiment lies in the configuration of the air flow channel 20. In addition, a runner groove 38 is provided on the side of the groove 18. When the support substrate 37 and the buffer material 31 are overlapped, the runner groove 38 of the support substrate 17 communicates with the second through hole 12 of the buffer material 31.

The outer dimensions of the support substrate 37 are larger than the fuel cell 29, the buffer material 31, and the distribution plate 33. In addition, in the example of FIG. 15, the air flow passage 20 is provided at only one place, but it may be provided at a plurality of places.

FIG. 16 is a cross-sectional view of a fuel cell module 39 related to Embodiment 2 of the present invention. The fuel cell module 39 is constructed by stacking one or more structural units on the supporting substrate 37 (37b), for example.

The support substrate 37b arranged on the lower side is formed into a shape in which the support substrate 37 of FIG. 15 is inverted left and right (mirror inversion). In addition, the constituent unit is formed by stacking the following components in order from the bottom. ‐ Buffer material 31 that reverses left and right (that is, rotates 180 degrees around the axis X in Figure 13) ‐The fuel cell 29 that is reversed left and right (that is, rotated 180 degrees around the axis X in Fig. 12) ‐ Buffer material 31 that reverses left and right (that is, rotates 180 degrees around the axis X in Figure 13) ‐Distribution plate 33 ‐Buffer material 31 ‐Fuel cell 29 ‐Buffer material 31 ‐Distribution plate 33 with left-right reversal (that is, 180 degrees around the axis X in Figure 14)

In the example of FIG. 16, it is the repetition of two constituent units, but the number of constituent units is one or more and can be changed arbitrarily. In addition, in the uppermost structural unit, a support substrate 37 (37a) is arranged in place of the uppermost distributor plate 33.

In addition, a pressure 23 is applied to the supporting substrates 37a, 37b by a pressure mechanism not shown. Thereby, the buffer material 31 arranged between each layer is deformed, and the leakage of fuel gas and air is prevented. The air flow passage 20 and the fuel gas flow passage 21 of the supporting substrates 37a and 37b are connected to an external gas pipe, so that the fuel gas and air can be blown and exhausted.

Next, the flow of fuel gas and air will be explained. In Fig. 16, solid arrows indicate the flow of fuel gas, and dotted arrows indicate the flow of air. The flow of each gas can be known from the arrow in Fig. 16 and the structure of each component shown in Fig. 12 to Fig. 15. It is only for reference and supplementary explanation as follows.

First, the fuel gas enters from the fuel gas flow channel 21 of the upper support substrate 37a, and sequentially passes through the second through hole 12 of the uppermost buffer material 31, the second opening 9 of the uppermost fuel cell 29, and the second opening 9 of the uppermost fuel cell 29. The second through hole 12 of the two-stage buffer material 31 reaches the upper flow passage 14 of the distribution plate 33.

The fuel gas branches up and down through the first through hole 16 of the valve plate from the upper flow channel 14 and reaches the first opening 8 of the fuel cell 29 in the uppermost and second stages, as in the first embodiment. In this way, the fuel gas is supplied to the first power generation element 7 in the fuel cell 29 in the uppermost stage and the second stage.

After that, the fuel gas merges at the center of the valve plate 33 in the same manner as in the first embodiment, and diverges again. In this way, the fuel gas is supplied to the second power generation element 7 of the fuel cell 29 in the uppermost stage and the second stage.

After that, the fuel gas passes through the gas flow passage 36 for turning of the valve plate 33 and merges. After that, the fuel gas is supplied to the third power generation element 7 of the fuel cell cell 29 in the uppermost stage and the second stage, and is further supplied to the fourth power generation element 7 of the fuel cell cell 29 in the uppermost stage and the second stage.

After that, the fuel gas sequentially passes through the gas discharge channel 35, the second through hole 12 of the buffer material 31, the second opening 9 of the second stage fuel cell 29, and the second through hole 12 of the buffer material 31, Go down and pass. In this way, the fuel gas is exhausted from the upper constituent unit.

After that, the fuel gas circulates in the constituent unit on the lower side. In this way, the fuel gas is supplied to the fuel cell 29 in the third and fourth stages. After that, the fuel gas is exhausted from the fuel gas flow passage 21 of the lower support substrate 37b.

As shown in FIG. 16, the air enters from the air flow passage 20 of the upper support substrate 37 a and reaches the second electrode 6 of the power generating element 7 of the fuel cell 29 at the uppermost stage. After that, the air in each stage passes through the third through hole 32 of the buffer material 31, the third opening 30 of the fuel cell 29, the second through hole 34 of the valve plate 33, etc., and is supplied to the second through hole 34 of the second stage. The second electrode 6 of the power generating element 7 of the fuel cell 29.

Thereafter, the air passes through the third through hole 32 of the buffer material 31, the third opening 30 of the fuel cell 29, the second through hole 34 of the valve plate 33, etc. in the same manner in each section, and is supported by the lower side The air flow channel 20 of the substrate 37b is discharged.

In this way, in the second embodiment, a plurality of gas passages are constituted inside the fuel cell module 39, especially the fuel gas passage, and the air passage are constituted separately. In addition, as the passage of each gas, the passage of the fuel cell 29 communicates with the passage of the distribution plate 13 to constitute a common passage. One of the common passages is a passage for fuel gas, and the other common passage is a passage for air. Thereby, the fuel gas and the air are separated and circulated. In this way, the mixing of fuel gas and air is avoided.

In addition, the fuel cell system can be configured similarly to Embodiment 1 (FIG. 11). In the fuel cell system, by keeping the fuel cell module 39 at a certain temperature (for example, 300°C to 600°C), high-efficiency and stable power generation can be achieved.

The fuel cell module 39 of Embodiment 2 can stack dozens of layers of fuel cell cells 29 to generate power with a large output.

In addition, the fuel cell 29 and the distribution plate 33 can be made using a silicon substrate, so the thickness of the entire fuel cell module 39 including the buffer material 31 can be reduced. Therefore, it is possible to reduce the volume of the housing in which the fuel cell module 39 is housed, and it is possible to provide a small-sized fuel cell system with good heat dissipation efficiency.

In addition, as in the modification of Embodiment 1 (FIG. 2 ), by providing a sensor in the fuel cell cell, for example, when the output of any fuel cell cell decreases, this situation can be detected and exchange can be easily performed. In addition, as the sensor, for example, a gas sensor may be provided in the fuel cell. In this way, even if a gas leak occurs due to a failure of the buffer material or the distribution plate, it can be detected and exchanged easily, so the maintainability is excellent. <Implementation Type 3> Fig. 17 is a plan view of a fuel cell 40 related to Embodiment 3 of the present invention. The configuration of the first insulating film 3 of the fuel cell 40, the power generating element 7 (first electrode, electrolyte layer, and second electrode), and the plurality of first openings 8 are the same as those of the fuel cell 1 of the first embodiment.

The difference from the first embodiment is that the fuel cell 40 is provided with a plurality of second openings 9 and third openings 30, respectively.

FIG. 18 is a plan view of the cushion material 41 related to Embodiment 3 of the present invention. Three first through holes 11 similar to the buffer material 10 of the first embodiment are provided. In addition, a fourth through hole 42 in which a runner groove 42a is provided as a protrusion is provided. Furthermore, a fifth through hole 43 smaller than the first through hole 11 and the fourth through hole 42 is formed. In addition, the fifth through-hole 43 may be formed in plural (two in the example of FIG. 18).

FIG. 19 is a plan view and a cross-sectional view of the distribution plate 44 related to Embodiment 3 of the present invention. The distribution plate 44 is formed with a supply-side flow passage 45 and a discharge-side flow passage 46. The supply-side flow passage 45 and the discharge-side flow passage 46 are separated from each other in the inside of the distribution plate 44 and communicate with the outside of the distribution plate 44 and the second through hole 47 of the distribution plate.

In addition, in the distribution plate 44, a plurality of third through holes 48 (two in the example of FIG. 19) that penetrate the distribution plate 44 up and down are provided. The third through hole 48 of the distribution plate is separated from the supply side flow passage 45 and the discharge side flow passage 46.

When the fuel cell 40 and the buffer material 41 are overlapped, one of the second openings 9 of the fuel cell 40 overlaps and communicates with the flow channel groove 42a of the buffer material 41 to supply fuel gas. In addition, the third opening 30 of the fuel cell 40 overlaps and communicates with the fifth through hole 43 of the buffer material 41, and supplies air.

Furthermore, the buffer material 41 overlaps with the valve plate 44. The fuel gas that has reached the fourth through hole 42 of the buffer material 41 flows into the supply side flow passage 45 of the distribution plate 44, and is supplied to the four power generating elements 7 through the second through hole 47 of the distribution plate. Furthermore, as shown in FIG. 17, the four power generating elements 7 are separately arranged, but as shown in FIGS. 18 and 19, the gas reaching the fourth through hole 42 is divided by the distribution plate 44 and distributed to all the power generating elements 7.

The consumed fuel gas merges in the discharge side flow passage 46 of the valve plate 44. On the lower side of the distribution plate 44, the buffer material 41 is reversed left and right (that is, rotated 180 degrees around the axis X in FIG. 18) and overlapped, whereby the flow channel groove 42a of the buffer material 41 discharges the fuel gas.

In the buffer material 41, four through-holes (three first through-holes 11 and one fourth through-hole 42) are provided separately. The four through holes respectively supply unconsumed fuel gas.

That is, even if the first opening 8 of the fuel cell cells arranged above and below it is supplied with unconsumed fuel gas, the power generation efficiency is improved. In addition, by stacking the layers in the aforementioned steps so that the fuel gas and air are not mixed, the fuel cell module can be constructed in the same manner as in the second embodiment.

Regarding the fuel cell module of the third embodiment, as described above, the distribution plate 44 separates the supply side flow passage 45 and the discharge side flow passage 46 to improve the fuel gas consumption efficiency. This improves the power generation output per fuel cell layer. Therefore, for example, the number of layers of fuel cell cells can be reduced, and the fuel cell module can be miniaturized. In addition, fuel gas can be used efficiently.

<Modifications of the present invention> The present invention is not limited to the aforementioned embodiments and modifications, but also includes various other modifications. For example, the foregoing embodiment has been described in detail in order to make the present invention easy to understand, but it is not limited to having all the configurations previously described. In addition, it is also possible to replace a part of the structure of a certain implementation type with the structure of another implementation type. In addition, it is also possible to add the structure of a certain implementation type to the structure of other implementation types. In addition, it is possible to perform addition, deletion, and replacement of other configurations for a part of the configuration of each embodiment.

1(1a, 1b), 29, 40: fuel cell 2: Semiconductor substrate 3: The first insulating film 4: The first electrode (electrode layer) 5: Electrolyte layer 6: The second electrode (electrode layer) 7: Power generation components 8: The first opening 9: The second opening 10(10a,10b,10c,10d),31,41: buffer material 11: 1st through hole 12: 2nd through hole 13,33,44: distribution plate 14: Upper runner 15: Lower runner 16: The first through hole of the valve plate 17 (17a, 17b), 37 (37a, 37b): support substrate 18: Groove 19: Column 20: Air flow path 21: Fuel gas flow path 22, 39: Fuel cell module 23: Stress 24: Blower 25: Modifier 26: Pressure regulator 27: Chassis 28: Burner 30: The third opening 32: 3rd through hole 34: The second through hole of the valve plate 35: Gas discharge channel 36: Gas flow path for rotation 38, 42a: runner trench 42: 4th through hole 43: 5th through hole 45: Supply side runner 46: discharge side runner 47: The second through hole of the valve plate 48: The third through hole of the valve plate

[Fig. 1] A plan view of a fuel cell related to Embodiment 1. [Fig. [Fig. 2] is a cross-sectional view taken along the line A-A in Fig. 1. [Fig. 3] It is a plan view of the cushioning material related to the first embodiment. [Fig. 4] is a cross-sectional view taken along the line A-A in Fig. 3. [Fig. [Fig. 5] It is a plan view of the distribution plate related to the first embodiment. [Fig. 6] is a cross-sectional view taken along the line A-A in Fig. 5. [Fig. [Fig. 7] is a cross-sectional view taken along the line B-B in Fig. 5. [Fig. [Fig. 8] A plan view of a supporting substrate related to Embodiment 1. [Fig. [Fig. 9] is a cross-sectional view taken along the line A-A in Fig. 8. [Fig. [Fig. 10] is a cross-sectional view of the fuel cell module related to Embodiment 1. [Fig. Fig. 11 is a schematic diagram of a fuel cell system related to Embodiment 1. [Fig. 12] A plan view of a fuel cell related to Embodiment Mode 2. [Fig. [Fig. 13] is a plan view of the cushioning material related to the second embodiment. [Fig. 14] A plan view and a cross-sectional view of the distribution plate related to the second embodiment. [Fig. 15] A plan view of a supporting substrate related to Embodiment Mode 2. [Fig. [Fig. 16] is a cross-sectional view of a fuel cell module related to Embodiment 2. [Fig. [Fig. 17] A plan view of a fuel cell related to Embodiment Mode 3. [Fig. [Fig. 18] is a plan view of the cushioning material related to the third embodiment. [Fig. 19] It is a plan view and a cross-sectional view of the distribution plate related to the third embodiment.

1a, 1b: fuel cell 10a, 10b, 10c, 10d: buffer material 13: distribution plate 17a, 17b: Support substrate 20: Air flow path 21: Fuel gas flow path 22: Fuel cell module 23: Stress

Claims (10)

A fuel cell module includes: a plurality of fuel cell cells and at least one distribution plate; each of the fuel cell cells includes at least one power generation element; the power generation element includes: an electrolyte layer, and 2 sandwiching the electrolyte layer The electrode layer; the valve plate, which defines a passage for at least one of the fuel gas or oxidant gas supplied to the electrode layer; the valve plate, has a first surface and a second surface; the valve plate has a plurality of A through hole that penetrates from one side to the second side; the through hole diverges the passage to the first and second sides, then merges, then diverges again, and then merges. The fuel cell module according to claim 1, wherein the fuel cell module further includes a buffer material arranged between the fuel cell cell and the valve plate; the buffer material has a through hole that defines the passage. A fuel cell module according to claim 2, wherein the fuel cell module further includes a support substrate for supporting the buffer material; the support substrate has an opening that opens toward the power generating element. Such as the fuel cell module of claim 1, wherein the aforementioned distribution plate is made of silicon or ceramic. Such as the fuel cell module of claim 1, in which one of the aforementioned distribution plates delimits a passage connecting a plurality of aforementioned power generating elements. The fuel cell module of claim 2, wherein the buffer material is connected to at least one of the valve plate or the fuel cell cell. The fuel cell module of claim 1, wherein the fuel cell cell has a sensor that detects at least one of the failure, temperature, humidity, and pressure of the fuel cell cell. The fuel cell module of claim 1, wherein the fuel cell cell defines a passage through which at least one of the fuel gas or the oxidant gas supplied to the electrode layer flows; the passage of the fuel cell cell is connected to the valve plate The aforementioned passages are connected to form a common passage. Such as the fuel cell module of claim 8, wherein the aforementioned common passages are constituted in plural, one of the aforementioned common passages is the passage of the aforementioned fuel gas, and the other aforementioned common passages are the passages of the aforementioned oxidant gas, whereby the aforementioned fuel The gas and the aforementioned oxidant gas are separated and circulated. A fuel cell system includes: the fuel cell module of claim 1, and a housing for controlling the temperature of the fuel cell module.

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