JP4604445B2 - Fuel cell system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a fuel cell humidifying device and an air humidifying method for humidifying air or fuel supplied to a fuel cell.
[0002]
[Prior art]
In general, in a fuel cell, water needs to be present in a solid polymer membrane when performing a power generation reaction by passing hydrogen ions through the solid polymer electrolyte membrane. There are various methods for supplying the moisture. For example, Patent Document 1 describes a configuration in which the reaction gas is humidified by the power generation water contained in the off-gas of the fuel cell.
[0003]
[Patent Document 1]
Japanese Patent No. 3111697 (page 3 [0010] and FIG. 1)
[0004]
[Problems to be solved by the invention]
In the method described in Patent Document 1, since the generated water and generated heat are proportional to the supply amount of the reaction gas, humidification and preheating are performed without stagnation, and the humidified reaction gas is supplied to the fuel cell in response to load fluctuations. can do. However, it is difficult to obtain a sufficient amount of humidification only by humidification of water vapor contained in the off-gas of the fuel cell. In addition, there is a method of performing humidification using cooling water that is cooled by warming the fuel cell, but for the humidification from the cooling water, pure water must be used as the cooling water, but to prevent freezing of the cooling water. Since it is desirable to use antifreeze liquid, humidification with cooling water is not suitable.
[0005]
The present invention has been made to solve such problems, and an object of the present invention is to provide a fuel cell capable of humidifying a supply air as a reaction gas in a saturated state.
[0006]
It is another object of the present invention to provide a fuel cell capable of humidifying supply air regardless of the quality of the cooling water of the fuel cell.
[0007]
[Means for Solving the Problems]
  A fuel cell system according to claim 1 of the present invention is a fuel cell having a fuel electrode and an oxidant electrode disposed on both surfaces of a solid polymer film, and a cooling section for flowing cooling water, and allows water vapor to pass therethrough. From a moisture permeable membrane, an air supply channel provided on the first main surface of the moisture permeable membrane and for supplying supply air, and the oxidant electrode of the fuel cell provided on the second main surface of the moisture permeable membrane An exhaust passage for allowing the exhaust gas to pass through, and hot water for heating the exhaust gas from the oxidant electrode of the fuel cell supplied to the exhaust passageFlowA humidifier equipped with a passage, a blower for supplying air to the air supply passage, a first cooling water passage connecting the cooling section and the hot water section, and a first connecting the hot water section and the cooling section. Cooling water is heated by the heat generated in the fuel cell in the cooling unit, and the cooling unit, the first cooling water channel, the hot water channel, the second water channel Circulating in order of cooling water passageThe exhaust flow path is formed so that the exhaust air flows directly under gravity or in a horizontal direction and does not include an upward flow direction, and the flow direction of the exhaust air flowing through the exhaust flow path is The direction of the flow of the hot water flowing through the hot water channel is opposite to the direction of the flow of the supply air flowing through the air flow path.It is characterized by that.
[0008]
  The invention described in claim 2 of the present invention is described in claim 1.Fuel cell systemInA water recovery means for recovering water contained in exhaust gas from the oxidant electrode of the fuel cell is provided, and the water recovered by the water recovery means is heated by the hot water channel.It is characterized by that.
[0009]
  The invention described in claim 3 of the present invention is described in claim 2.Fuel cell systemInThe moisture recovery means is a trapIt is characterized by that.
[0010]
  The invention described in claim 4 of the present invention is described in claim 2.Fuel cell systemInThe moisture recovery means has a steam / water separator, and a water retention part is provided at a lower portion of the steam / water separator.It is characterized by that.
[0011]
  According to claim 5 of the present inventionThe present invention provides the fuel cell system according to claim 1, wherein the humidifier comprises:
One or a plurality of units in which the moisture permeable membrane, the air supply channel, the exhaust channel, and the hot water channel are integrated are stacked.It is characterized by that.
[0013]
  Claims of the invention6The invention described in claim 2 is described in claim 2.Fuel cell systemInThe warm water channel is arranged adjacent to the water recovery meansIt is characterized by that.
[0014]
  Claims of the invention7The invention described in claim2Described inFuel cell systemInThe moisture recovery means is a trap provided in the exhaust passage connected to an exhaust passage, and the trap is formed in common for a plurality of units.It is characterized by that.
[0015]
  Claims of the invention8The invention described in claim2Described inFuel cell systemInThe moisture recovery means is one or a plurality of traps arranged in the exhaust passage, and the traps are formed in each of the plurality of units.It is characterized by that.
[0026]
DETAILED DESCRIPTION OF THE INVENTION
The humidifier for a fuel cell according to the present invention includes a moisture permeable membrane that transmits water vapor, an air passage that is provided on a first main surface of the moisture permeable membrane and flows air, and a second main surface of the moisture permeable membrane. A supply path for supplying pure water or water vapor, a fluid supply means for supplying at least one of exhaust gas of the fuel cell and pure water to the supply path, and a heating means for heating the fluid supplied to the supply path It is equipped with.
[0027]
According to the present invention, supply air that is a reaction gas can be saturated and humidified by a humidification system having a simple configuration. Further, the supply air can be humidified regardless of the quality of the cooling water of the fuel cell, and liquids other than pure water such as antifreeze can be used.
[0028]
In another embodiment, the fuel cell exhaust is supplied by the fluid supply means, and the water recovery means recovers the water contained in the supplied exhaust gas, and the water recovered by the water recovery means is collected. It is heated by a heating means. According to the present invention, in addition to humidification by the water vapor in the exhaust gas, the supply air can be humidified by the water vapor generated by collecting the water in the exhaust gas. Can be humidified.
[0029]
In another embodiment, the exhaust of the fuel cell is supplied to the replenishment path by the fluid supply means, and a trap that is a moisture recovery means is provided in the replenishment path. And according to this invention, the water | moisture content contained in exhaust air can be collect | recovered by a simple method.
[0030]
In another embodiment, the water recovery means includes a steam / water separator in a replenishment path for supplying exhaust gas, and a water retention part at a lower portion of the steam / water separator. And according to this invention, the water | moisture content contained in exhaust air can be collect | recovered by a simple method.
[0031]
In another embodiment, the moisture permeable membrane that transmits water vapor, the air flow path provided on the first main surface of the moisture permeable membrane, and the second main surface of the moisture permeable membrane are provided. 1 unit comprising a pure water or water vapor replenishment path, fluid supply means for supplying at least one of exhaust gas and pure water to the replenishment path, and heating means for heating the fluid flowing in the replenishment path. One or a plurality are stacked. And according to this invention, the humidification apparatus for fuel cells can be reduced in size by simple structure.
[0032]
In another embodiment, the heating means is cooling water that cools the fuel cell. According to the present invention, since the heat generated by the fuel cell is effectively used, no new heat source is required.
[0033]
In another embodiment, the moisture recovery means is provided in a supply path provided on the second main surface of the moisture permeable membrane, and the heating means is disposed adjacent to the moisture recovery means. . And according to this invention, the humidification apparatus for fuel cells can be reduced in size by simple structure.
[0034]
In another embodiment, the moisture recovery means is a trap provided in an exhaust passage connected to a supply path, and the trap is formed in common for a plurality of units. According to the present invention, since the humidifying mechanism using the recovered water can be attached externally, the humidifying mechanism can be easily added even to an existing apparatus that does not include this apparatus.
[0035]
In another embodiment, the moisture recovery means is one or a plurality of traps arranged in the replenishment path, and the traps are formed in each of the plurality of units. According to the present invention, the air humidification amount can be freely controlled by adjusting the number of air humidification units.
[0036]
In another embodiment, the area of the water retention portion that contacts the moisture permeable membrane is 10 to 50% of the area of the moisture permeable membrane. According to the present invention, saturation humidification can be reliably performed with a simple configuration.
[0037]
In another embodiment, the fluid flow direction in the replenishment path and the supply air flow direction in the air flow path are opposed to each other. And according to this invention, humidification of supply air can be performed efficiently.
[0038]
In another embodiment, the heating means is cooling water that has cooled the fuel cell, and includes a reduction means that reduces the temperature difference between the cooling water and the temperature of the humidified water flowing through the fluid flow path. And according to this invention, heat transfer from cooling water to humidification water is performed rapidly, and generation | occurrence | production of the water vapor | steam from humidification water is accelerated | stimulated. Therefore, it is possible to quickly humidify the supply air flowing through the supply air flow path.
[0039]
In another embodiment, the reducing means for reducing the temperature difference is a means for circulating the humidified water in the fluid passage in the replenishment path. And according to this invention, the heat transfer from cooling water to humidification water is performed rapidly.
[0040]
In another embodiment, the reducing means for reducing the temperature difference is a means for expanding the contact area between the fluid flow path and the heating means. And according to this invention, the heat transfer from cooling water to humidification water is performed rapidly.
[0041]
In another embodiment, the reducing means for reducing the temperature difference is a means for branching a part of the air supplied to the air flow path and supplying it into the replenishment path, and stirring the humidified water in the replenishment path It is intended to promote heat transfer. And according to this invention, the heat transfer from cooling water to humidification water is performed rapidly.
[0042]
In another embodiment, a vibration means for vibrating the heat transfer surface between the heating means and the replenishment path is provided. And according to this invention, the heat transfer from cooling water to humidification water is performed rapidly.
[0043]
In another embodiment, pulsation means for vibrating the heat transfer surface between the air flow path and the supply path is provided. And according to this invention, the heat transfer from cooling water to humidification water is performed rapidly.
[0044]
The fuel cell air humidification method according to the present invention includes a first step of recovering moisture from the exhaust of the fuel cell, a second step of heating the recovered moisture, and water vapor in the exhaust to the fuel cell. A third step of humidifying the supplied air and a fourth step of humidifying the air with water vapor generated in the second step are provided. According to the present invention, in addition to humidification by the water vapor in the exhaust gas, the supply air can be humidified by the water vapor generated by collecting the water in the exhaust gas. Can be humidified.
[0045]
In another embodiment, humidification is performed in the fourth step after the third step. According to the present invention, the humidification amount can be freely controlled according to the supplied air amount.
[0046]
Embodiments of the present invention will be described below with reference to the drawings.
[0047]
Example 1
FIG. 1 shows a conceptual diagram of the fuel cell and its air supply system in the first embodiment of the present invention. In the fuel cell 1, for example, as described in FIG. 2 of Patent Document 1, a fuel electrode and an oxidant electrode are arranged on both surfaces of a solid polymer film, and hydrogen as a fuel and oxygen (air) as an oxidant. To generate electricity. The heat generated when generating electricity is cooled by the cooling water supplied from the pump 2 to the cooling unit 4 of the fuel cell 1 through the cooling water passage A3. The cooling water is heated by the heat generated in the fuel cell 1 in the cooling unit 4 and supplied to the hot water passage 7 of the humidifier 6 through the cooling water passage B5. The cooling water passing through the hot water passage 7 is the cooling water. It circulates to the pump 2 through the passage C8.
[0048]
In the humidifier 6, an air supply passage 10 that allows air as an oxidant to pass therethrough and an exhaust passage 11 that passes exhaust from the fuel cell 1 are formed on one side of the moisture permeable membrane 9. Thus, a hot water flow path 7 through which the hot water from the cooling unit 4 passes is provided. Air as an oxidant is supplied from the blower 12 to the air supply passage 10 of the humidifier 6, and the air is further supplied to the fuel cell 1 through the air passage 13 and supplied from the hydrogen cylinder 14 through the fuel passage 15. Hydrogen reacts with oxygen in the air to generate electricity and produce water. This water is contained in the exhaust air and supplied to the exhaust passage 11 of the humidifier 6 through the exhaust passage 16. The exhaust gas on the fuel electrode side is exhausted through the exhaust gas passage 17.
[0049]
The structure of the humidifier 6 is shown in FIG. As shown in FIG. 2A, the humidifier 6 has a unit structure in which one or a plurality of single units 18a are stacked. In the single unit 18a, a flow path is formed so that the exhaust air and the supply air face each other as shown in FIG. 2 (b). The hot water channel is formed so as to flow in from the center and flow in a zigzag manner in the single unit 18a.
[0050]
Since the moisture permeable membrane 9 is extremely thin and soft, the entire surface of the moisture permeable membrane 9 is covered with a porous or mesh support 19 and fixed to the rib 20 as shown in FIGS. 3 (a) and 3 (b). . Since the support 19 serves as a heat transfer surface of the moisture permeable membrane 9, stainless steel, which is a material that has high heat transfer and corrosion resistance and does not allow metal ions to flow out, is suitable. As the porous or mesh-like lattice, a net, cloth, punching plate, non-woven cloth, etc. can be used. The rib 20 is made of a resin such as polypropylene, polyvinyl chloride, polyethylene, or polyimide.
[0051]
Returning to FIG. 2 (a), the air supply channel 10 is formed on one main surface side of the moisture permeable membrane 9, and is partitioned by a plurality of partition plates 22 formed on the wall surface 21 as shown in FIG. 2 (c). The air supply channel 10 is configured. When the stacked unit units 18a are installed vertically, the air supply passage 10 and the air inlet 23 and the air so that the supply air does not flow upward from below as shown in FIG. 4A. An outlet 24 is arranged.
[0052]
Each air supply channel 10 is formed in a region surrounded by the adjacent partition plates 22 and the wall surface 21 and the moisture permeable membrane 9, and has a unit structure so that the single unit 18a is in the vertical direction as shown in FIG. When arranged, it has a height of an interval h between the partition plates 22 (see FIG. 2C) and a width of an interval t between the wall surface 21 and the moisture permeable membrane 9 (see FIG. 2A). Is preferably about 5 mm or less.
[0053]
An exhaust passage 11 is formed on the main surface opposite to the moisture permeable membrane 9. As shown in FIG. 2C, the exhaust passage 11 is composed of a plurality of exhaust passages 11 partitioned by a partition plate A26 formed on the wall surface A25. As shown in FIG. 4A, the exhaust inlet 27 and the exhaust outlet 28 are arranged so that the exhaust air does not flow upward from below.
[0054]
The partition plate A26 is formed with one or a plurality of traps 29 for collecting moisture in the exhaust gas. When exhaust air containing moisture passes through the exhaust passage 11 between the partition plates A26, the moisture is trapped 29. And the water is separated from the exhaust air.
[0055]
As shown in FIG. 2 (b), the direction of the exhaust air flow 30 flowing through the exhaust flow path 11 is preferably a counter flow that is opposite to the direction of the supply air flow 31 flowing through the supply air flow path 10. . Further, since the exhaust air contains moisture, the exhaust passage 11 is arranged to flow directly under the gravity or in the horizontal direction, and is directed upward from below, from right to left, from left to right, or provided with a plurality of straight or folded portions. The flow direction is not included.
[0056]
Each exhaust passage 11 is formed in a region surrounded by the adjacent partition plates A26, the wall surface A25, and the moisture permeable membrane 9, and has a unit structure so that the single unit 18a is vertical as shown in FIG. When arrange | positioning, it has the width | variety of the space | interval T (refer Fig.2 (a)) between wall surface A25 and the moisture-permeable film 9. FIG. In the exhaust passage 11, the pressure of the exhaust air is lower than the pressure of the supply air, so that the moisture permeable membrane 9 sag toward the exhaust passage 11 due to this pressure difference and tends to be smaller than the actual interval T. Therefore, the interval T between the exhaust passages 11 is preferably larger than the interval t between the supply passages 10.
[0057]
By making the wall surface A25 of the exhaust passage 11 hydrophilic, water in the exhaust air is uniformly supplied to the wall surface, so that pressure loss can be reduced. On the other hand, if water repellency is used, water in the exhaust air hardly adheres to the wall surface A25, so that the condensed water can be easily dropped and collected by the trap 29. Which one is selected is arbitrary depending on the use conditions. Hydrophilic and water repellent processing is performed by coating the wall surface A25.
[0058]
A hot water flow path 7 is formed on the back side of the exhaust flow path 11. The hot water channel 7 is provided with a hot water channel 7 formed in a zigzag shape on the wall surface A25 on the opposite side of the exhaust channel 11, and the water trapped in the trap 29 of the exhaust channel 11 by the hot water flowing through the hot water channel 7 Warm up.
[0059]
As shown in FIG. 2 (b), the direction of the hot water flow 32 is a direction opposite to the direction of the supply air flow 31, and flows in a zigzag shape from the central portion of each single unit 18a to the center on the opposite side. Set to be discharged from the section.
[0060]
The role of the rib 20 described in FIG. 3 is played by the partition plate 22 and the partition plate A 26 described in FIG.
[0061]
Further, as shown in FIG. 4 (b), the air inlets 23a to 23c, the air outlets 24a to 24c, the exhaust inlets 27a to 27c, and the exhaust outlets 28a to 28c may be respectively provided to form a multi-header configuration. The supply air flow 31 flowing through the air flow path 10 and the exhaust air flow 30 flowing through the exhaust flow path 11 flow more evenly.
[0062]
Next, the operation will be described. Fuel hydrogen from the hydrogen cylinder 14 is humidified as necessary and supplied to the fuel electrode of the fuel cell 1 through the fuel passage 15. On the other hand, the air from the blower 12 is humidified by the air supply passage 10 of the humidifier 6 and supplied to the fuel cell 1 from the air passage 13. In the fuel cell 1, hydrogen fuel from the hydrogen cylinder 14 and oxygen in the air from the blower 12 react to generate power. At this time, water is produced as a by-product. Water is contained as moisture in the exhaust air from the fuel cell 1 and supplied to the exhaust passage 11 of the humidifier 6 through the exhaust passage 16. As shown in FIG. 2 (c), the exhaust air supplied to the exhaust passage 11 recovers moisture by a trap 29, and part of the water vapor passes through the moisture permeable membrane 9 and passes through the air supply passage 10. Humidify the air. At this time, the pressure loss of the exhaust air can be reduced by making the wall surface of the exhaust passage 11 hydrophilic. Unreacted hydrogen gas is circulated from the exhaust gas passage 17 to the hydrogen cylinder 14 or discharged out of the system.
[0063]
On the other hand, the fuel cell 1 generates heat during power generation. This heat is cooled by the cooling water from the pump 2 in the cooling section 4, and the heated cooling water passes through the cooling water passage B5 from the cooling section 4. It is supplied to the hot water flow path 7 of the humidifier 6. The warm water passing through the warm water channel 7 warms the moisture trapped in the exhaust channel 11 to generate water vapor. The heating temperature at this time is preferably 0 to + 10 ° C. with respect to the vapor dew point temperature of the supply air, and a cooling water temperature control device may be provided as necessary. This water vapor also humidifies the supply air passing through the air supply passage 10 through the moisture permeable membrane 9. As a result, the air supplied to the fuel cell 1 is humidified to a saturated state. As a result, the supply air from the blower 12 as the oxidant is humidified by the water vapor trapped in the exhaust passage 11 at the same time as being humidified by the water vapor in the exhaust air, and thus supplied without supplying water from the outside. Air can be humidified to saturation. The water vapor that humidifies the air passing through the air supply channel 10 is water generated in the fuel cell 1, and this water is supplied again to the fuel cell 1 as humidified water in the humidified air. There is almost no consumption, and there is no need to replenish pure water from the outside.
[0064]
Further, the cooling water of the fuel cell is used only for heating the moisture in the exhaust air, and is not used as the moisture for humidification. Therefore, it is not necessary to manage the quality of the cooling water, and a liquid other than pure water such as an antifreeze can be used. Furthermore, since the configuration of the humidification system is very simple, maintenance is easy.
[0065]
The stacked single units 18a may be arranged either in the horizontal direction or in the vertical direction, and when arranged so as to be in the horizontal direction, it is preferable to arrange so that the exhaust flow path 11 of the single unit 18a is downward. When the exhaust flow path 11 is positioned downward, the water collected by the trap 29 accumulates on the wall surface A25 side and is easily heated by the hot water flow path 7. In addition, since the moisture permeable film 9 is not easily covered with moisture, the water vapor component in the exhaust air easily passes through the moisture permeable film 9 including the vapor generated by heating.
[0066]
When the stacked single units 18a are arranged so as to be in the vertical direction, the water collected by the trap 29 accumulates below and is similarly heated by the exhaust passage 11, and the water vapor component in the exhaust air is generated by heating. It is easy to reliably pass through the moisture permeable membrane 9 including the vapor.
[0067]
In the above description, the case where one or a plurality of traps 29 is provided in each single unit 18a has been described. However, one or a plurality of traps 29 may be provided in the unit of the humidifier 6 as a whole.
[0068]
(Example 2)
FIG. 5 shows a conceptual diagram of the fuel cell and its air supply system in the second embodiment of the present invention. The same parts as those in FIG. The difference from FIG. 1 is the configuration of the air supply passage 10 and the exhaust passage 11. This difference will be described with reference to FIG. The humidifier 6 is the same in that the single unit 18b or a plurality of single units 18b are stacked. The moisture permeable membrane 9 of the single unit 18b and the supporting method thereof are the same as those in the first embodiment.
[0069]
A first air supply flow path 33A and a second air supply flow path 33B which are divided vertically are formed on one main surface of the moisture permeable membrane 9. Each of the first air supply flow path 33A and the second air supply flow path 33B is composed of a plurality of flow paths partitioned by a partition plate B36 formed on the wall surface B35 as shown in FIG. The first air supply channel 33A and the second air supply channel 33B are formed so that the directions are opposite to each other. When this is seen in FIG. 6B, the direction of the flow B37 of the supply air flows in the left direction from the inlet of the upper first air supply flow path 33A and is folded downward at the opposite end portion to be second supplied. The air enters the air flow path 33B, proceeds in the right direction, and is supplied to the fuel cell 1 through the air passage 13 from the outlet of the second air supply flow path 33B on the inlet side of the first air supply flow path 33A.
[0070]
On the opposite main surface of the moisture permeable membrane 9, an exhaust passage B38 and a water storage section 39 are formed in a portion facing the first air supply passage 33A. As shown in FIG. 6C, the exhaust passage B38 is composed of a plurality of exhaust passages B34 partitioned by a plurality of partition plates C41 formed on the wall surface C40, and the partition plate C41 collects moisture in the exhaust air. It has a function. When the exhaust air containing moisture passes through each exhaust passage B34, the moisture drops 42 and is captured as condensed water in the lower water reservoir 39. In this case, dripping condensed water is promoted by making the wall surface of the exhaust passage B34 water-repellent. As shown in FIGS. 6B and 6C, the direction of the exhaust air flow B43 is formed to be opposite to the direction of the supply air flow B37 flowing through the first air supply passage 29A. Further, the water reservoir 39 below the exhaust passage B38 is formed in a portion facing the second air supply passage 33B, and a hot water passage B44 is formed on the back side thereof. It is preferable that the ratio of the area of the water reservoir 39 to the area of the moisture permeable membrane 9 which is a humidified area is 10 to 50%. As shown in FIGS. 6B and 6C, the hot water flow path B44 has a hot water flow B45 formed in a zigzag shape, and this hot water flow B45 is opposed to the direction of the supply air flow B37. The water in the water reservoir 39 is heated by the hot water flowing in the direction.
[0071]
Next, the operation will be described. The power generation, water generation and exhaust generation processes in the fuel cell 1 are the same as in the first embodiment. The generated water is contained as moisture in the exhaust air from the fuel cell 1, and is supplied to the exhaust passage B 38 of the humidifier 6 through the exhaust passage 16. As shown in FIG. 6C, moisture is trapped in the exhaust air supplied to the exhaust flow path B38 and collected in the water reservoir 39, and part of the water vapor passes through the moisture permeable membrane 9 to the first supply. The supply air passing through the air flow path 33A is humidified.
[0072]
On the other hand, the heat generated by the fuel cell 1 is cooled by the cooling unit 4 by the cooling water from the pump 2, and the cooling water heated from the cooling unit 4 passes through the cooling water passage B <b> 5 and the hot water channel of the humidifier 6. To B44. The warm water passing through the warm water flow path B44 heats the water collected in the water storage unit 39 and generates water vapor. The water vapor humidifies the supply air that passes through the moisture permeable membrane 9 and passes through the first air supply passage 33A. As a result, the supply air from the blower 12 as the oxidant is first humidified by the water vapor in the exhaust air, and then humidified by the water accumulated in the water reservoir 39, so that water supply from the outside is not performed. The supply air can be humidified to saturation.
[0073]
In addition, fuel cell cooling water is used only for heating the moisture in the exhaust air, not as moisture for humidification, so there is no need to control the quality of the cooling water, and it is not necessary to use pure water such as antifreeze. Liquid can be used. Further, the configuration of the humidification system is very simple, and maintenance is easy.
[0074]
In the above description, the case where the single water storage unit 39 is provided in each single unit 18b has been described, but a plurality of water storage units 39 may be provided in each single unit 18b. Moreover, you may make it provide the water storage part 39 in the unit of the whole humidifier 6 one place or multiple places.
[0075]
(Reference example 1)
  FIG. 7 illustrates the present invention.Reference example 11 is a conceptual diagram showing a fuel cell and its air supply system in FIG. The same parts as those in FIG. The difference from FIG. 1 is that a portion for collecting water in the exhaust air is provided outside the humidifier 6.
[0076]
In FIG. 7, an exhaust passage C <b> 46 is formed on the main surface of the moisture permeable membrane 9 opposite to the air supply passage 10. The exhaust passage C46 allows exhaust air to pass therethrough but does not have a function of collecting water contained in the exhaust. Therefore, in the structure of a single unit, the structure from which the trap 29 of the partition plate A26 was removed in the exhaust flow path 11 in FIG. 2 may be sufficient.
[0077]
In order to collect the water contained in the exhaust, an exhaust passage D48 provided outside the humidifier 6 is used. The exhaust flow path D48 has the same configuration as the exhaust flow path 11 in FIG. 2 or the exhaust flow path B34 in FIG. 6, and has a trap or a water storage part B49 for collecting water. The exhaust air is supplied to the exhaust passage C46 through the exhaust passage D48 and the coupling passage 50 coupled to the exhaust passage C46 of the humidifier 6. The hot water flow path 7 is adjacent to the water storage part B49, and the water in the water storage part B49 is heated by the cooling water from the cooling part 4.
[0078]
The power generation, water generation and exhaust generation processes in the fuel cell 1 are the same as in the first and second embodiments. The generated water is contained as moisture in the exhaust air from the fuel cell 1 and supplied to the exhaust passage D48 through the exhaust passage 16. A part of the moisture of the exhaust air supplied to the exhaust flow path D48 is trapped and the condensed water is recovered in the water storage part B49, and a part of the water vapor passes through the exhaust flow path D48 and the coupling passage 50 together with the exhaust air. 6 to the exhaust passage C46. The water vapor supplied to the exhaust passage C46 humidifies the supply air passing through the air supply passage 10 through the moisture permeable membrane 9.
[0079]
On the other hand, the condensed water collected in the water reservoir B49 is heated by warm water passing through the warm water flow path 7 to generate water vapor. This water vapor is supplied to the exhaust passage C46 of the humidifier 6 through the exhaust passage D48 and the coupling passage 50, and humidifies the supply air passing through the air supply passage 10 through the moisture permeable membrane 9. As a result, the supply air from the blower 12 as the oxidant is first humidified by the water vapor in the exhaust air and then humidified by the water accumulated in the water reservoir B49, so that water supply from the outside is not performed. The supply air can be humidified to saturation.
[0080]
In addition, fuel cell cooling water is used only for heating the moisture in the exhaust air, not as moisture for humidification, so there is no need to control the quality of the cooling water, and it is not necessary to use pure water such as antifreeze. Liquid can be used. Further, the configuration of the humidification system is very simple, and maintenance is easy.
[0081]
In the above description, the case where the water stored in the water storage unit B49 is the water from which the moisture in the exhaust air has been recovered has been described. However, pure water may be supplied from the outside as necessary.
[0082]
(Reference example 2)
  FIG. 8 illustrates the present invention.Reference example 21 is a conceptual diagram showing a fuel cell and its air supply system in FIG. The same parts as those in FIG. The difference from FIG. 1 is that pure water supplied from the outside is used instead of water vapor and moisture in the exhaust air as humidified water for the supply air.
[0083]
In FIG. 8, a humidified water channel 51 is provided on the main surface of the moisture permeable membrane 9 opposite to the air supply channel 10 instead of the exhaust channel 11 in FIG. The humidified water channel 51 is supplied with humidified water from the replenishment source 52, and the humidified water that has passed through the humidified water channel 51 is circulated to the replenishment source 52. Therefore, the exhaust air does not pass through the humidified water channel 51. The configuration of the humidifying water channel 51 may be a single unit configuration in which the trap 29 of the partition plate A26 is removed from the exhaust channel 11 in FIG.
[0084]
The power generation, water generation and exhaust generation processes in the fuel cell 1 are the same as in the first embodiment. The generated water is discharged from the exhaust air passage 53 together with the exhaust air.
[0085]
The humidification of the supply air in the humidifier 6 is performed by steam generated by heating the humidified water flowing in the humidified water channel 51 with the cooling water from the cooling unit 4 flowing in the hot water channel 7. The mechanism of humidification with water vapor is the same as that of the first embodiment described with reference to FIG.
[0086]
The water generated in the fuel cell 1 is not normally contaminated when it circulates in the fuel cell system. However, if the circulation system fails or is partially contaminated, the circulating water is contaminated. There is nothing to do. In the present embodiment, since fresh pure water is always supplied from the replenishment source 52 as humidified moisture of the supply air, the supply air is humidified even if the circulation system of the fuel cell 1 is broken or partly contaminated. Water vapor is not contaminated.
[0087]
Further, since the cooling water of the fuel cell 1 is used only for heating pure water flowing through the humidifying water channel 51 and is not used as moisture for humidification, it is not necessary to manage the quality of the cooling water, such as antifreeze. Liquids other than pure water can be used.
[0088]
Also in this embodiment, the stacked units may be arranged in the horizontal direction or in the vertical direction. That is, in any arrangement, the humidified water flowing in the humidified water flow path 51 is in direct contact with the moisture permeable membrane 9, so that the humidified water flowing in the humidified water flow path 51 is generated by being heated by the hot water flowing in the hot water flow path 7. Water vapor can surely pass through the moisture permeable membrane 9. Further, the moisture permeable membrane 9 is not damaged by the flow of the humidified water. Therefore, since the functions of heating, hydration and humidification are integrated in a compact manner and the installation direction is not selected, it is only necessary to supply water regardless of the heating means in the system design, which gives a great degree of freedom. .
[0089]
The heat of the hot water flowing through the hot water flow path 7 can use the exhaust heat of the entire fuel cell system in addition to the exhaust heat of the fuel cell 1 itself.
[0090]
(Reference example 3)
  FIG. 9 shows the present invention.Reference example 31 is a conceptual diagram showing a fuel cell and its air supply system in FIG. The same parts as those in FIG. 8 is different from the pure water from the replenishment source 52 as the water flowing through the humidified water flow path 51 in that the water contained in the exhaust air is also used.
[0091]
In FIG. 9, moisture in the exhaust gas exhausted from the exhaust air passage 53 is condensed by the condenser 55 and supplied to the humidified water passage 51 through the moisture supply passage 54. Therefore, both the pure water from the replenishment source 52 and the water in the exhaust gas of the fuel cell 1 are supplied to the humidified water channel 51. According to the present embodiment, the moisture generated by the fuel cell 1 can also be recovered and used effectively. The condenser 55 can be omitted if necessary.
[0092]
(Reference example 4)
  FIG. 10 shows the present invention.Reference example 41 is a conceptual diagram showing a fuel cell and its air supply system in FIG. The same parts as those in FIG. 8 is different from FIG. 8 in that there is a means for promoting the heating of the water flowing through the humidifying water channel 51. In FIG. 10, in addition to the humidified water from the replenishment source 52, water is circulated through the humidified water channel 51 through a separate water circulation path 56. The water in the water circulation path 56 is circulated by the pump 57, and the temperature difference between the temperature of the humidified water and the temperature of the hot water flowing through the hot water path 7 is obtained by stirring the humidified water supplied from the replenishment source 52 to the humidified water path 51. Make it small in a short time. As a result, heat transfer to the humidified water is promptly performed, and generation of water vapor from the humidified water is promoted. Therefore, it is possible to quickly humidify the supply air flowing through the air supply passage 10. In this case, if the temperature of the water from the pump 57 is heated, the heat transfer to the humidified water is further promoted.
[0093]
In addition, when the cooling water from the cooling unit 4 of the fuel cell 1 is pure water or an equivalent water quality, the cooling water from the cooling unit 4 is branched without using the pump 57 and the humidified water channel 51 is used. It is also possible to supply
[0094]
(Reference Example 5)
  FIG. 11 shows the present invention.Reference Example 51 is a conceptual diagram showing a fuel cell and its air supply system in FIG. The same parts as those in FIG. The difference from FIG. 8 is that the area of the boundary surface between the hot water channel 7 and the humidified water channel 51 is increased.
[0095]
In FIG. 11, irregularities 58 are formed on the boundary surface between the hot water channel 7 and the humidified water channel 51. As a result, the contact area between the hot water channel 7 and the humidified water channel 51 is expanded, so that the temperature of the hot water flowing through the hot water channel 7 is efficiently transmitted to the humidified water flowing through the humidified water channel 51, and heat to the humidified water is obtained. Transmission is performed quickly, and the generation of water vapor from the humidified water is promoted. Therefore, it is possible to quickly humidify the supply air flowing through the air supply passage 10.
[0096]
(Reference Example 6)
  FIG. 12 shows the present invention.Reference Example 61 is a conceptual diagram showing a fuel cell and its air supply system in FIG. The same parts as those in FIG. The difference from FIG. 8 is that a part of the supply air from the blower 12 is branched and supplied to the humidified water channel 51.
[0097]
In FIG. 12, the supply air from the blower 12 is branched by an air branch path 59 and supplied to the humidified water path 51. The air supplied from the air branch path 59 to the humidified water channel 51 stirs the humidified water supplied from the replenishment source 52 to the humidified water channel 51, and the temperature of the humidified water and the temperature of the hot water flowing through the hot water channel 7 are Reduce the temperature difference in a short time. As a result, heat transfer to the humidified water is promptly performed, and generation of water vapor from the humidified water is promoted. Therefore, it is possible to quickly humidify the supply air flowing through the air supply passage 10.
[0098]
In addition, if the temperature of the supplied air is heated by providing an air heater in the air branch path 59, the heat transfer to the pure water is further promoted.
[0099]
(Reference Example 7)
  FIG. 13 shows the present invention.Reference Example 71 is a conceptual diagram showing a fuel cell and its air supply system in FIG. The same parts as those in FIG. The difference from FIG. 8 is that a plunger pump is used as the pump B60 for circulating the cooling water, and the interface between the hot water flow path 7 and the humidified water flow path 51 is flexible and has a high thermal conductivity such as a thin metal film. It is a point made up of materials.
[0100]
In FIG. 13, when the boundary surface of the hot water flow path 7 and the humidified water flow path 51 is configured by a thin vibration film 61 and the cooling water is circulated through the hot water flow path 7 by the pump B60, the hot water flowing through the hot water flow path 7 is pump B60. Causes pulsation. Therefore, the vibration film 61 at the boundary surface between the hot water flow path 7 and the humidified water flow path 51 vibrates with the pulsation of the hot water. As a result, the humidified water flowing through the humidified water channel 51 is agitated, and the temperature difference between the temperature of the humidified water and the temperature of the warm water flowing through the hot water channel 7 is reduced in a short time. As a result, heat transfer to the humidified water is promptly performed, and generation of water vapor from the humidified water is promoted. Therefore, it is possible to quickly humidify the supply air flowing through the air supply passage 10.
[0101]
(Reference Example 8)
  FIG. 14 shows the present invention.Reference Example 81 is a conceptual diagram showing a fuel cell and its air supply system in FIG. The same parts as those in FIG. A difference from FIG. 8 is that a diaphragm type blower is used as the blower B62.
[0102]
In FIG. 14, when air is supplied to the air supply passage 10 by the blower B62, the supplied air pulsates according to the characteristics of the diaphragm type blower B62. Therefore, the moisture permeable membrane 9 adjacent to the air supply channel 10 vibrates in response to the pulsating air, and this vibration is transmitted to the humidified water flowing through the humidified water channel 51 so that the humidified water also vibrates. As a result, the humidified water is stirred, and the temperature difference between the temperature of the humidified water and the temperature of the warm water flowing through the warm water flow path 7 can be reduced in a short time. As a result, heat transfer to the humidified water is promptly performed, and generation of water vapor from the humidified water is promoted. Therefore, it is possible to quickly humidify the supply air flowing through the air supply passage 10.
[0103]
【The invention's effect】
As is clear from the above embodiments, according to the present invention, it is possible to provide a fuel cell that can saturate and humidify the supply air, which is a reaction gas, with a humidification system having a simple configuration.
[0104]
Further, since the humidified water covering the moisture permeable membrane does not basically perform forced circulation, the durability of the membrane increases and the degree of freedom of the structure increases. Further, the supply air can be humidified regardless of the quality of the cooling water of the fuel cell, and a liquid other than pure water such as antifreeze can be used as the cooling water.
[Brief description of the drawings]
FIG. 1 is a conceptual diagram showing the overall configuration of a fuel cell humidifier in Embodiment 1 of the present invention.
2A is a cross-sectional view showing the internal structure of a humidifier of a fuel cell humidifier according to Embodiment 1 of the present invention. FIG.
  (B) Front view showing the internal structure
  (C) Exploded perspective view showing the internal structure
3A is a side sectional view showing a support structure for a moisture permeable membrane used in a humidifier of a fuel cell humidifier in Embodiment 1 of the present invention. FIG.
  (B) Perspective view showing the support structure
4A is a side view of an air supply unit used in a humidifier of a fuel cell humidifier in Embodiment 1 of the present invention. FIG.
  (B) Plan view of the air supply unit
FIG. 5 is a conceptual diagram showing the overall configuration of a fuel cell humidifier in Embodiment 2 of the present invention.
6A is a cross-sectional view showing the internal structure of a humidifier of a fuel cell humidifier in Embodiment 2 of the present invention. FIG.
  (B) Front view showing the internal structure
  (C) Exploded perspective view showing the internal structure
[Fig. 7] of the present invention.Reference example 1Schematic diagram showing the overall configuration of a fuel cell humidifier
[Fig. 8] of the present inventionReference example 2Schematic diagram showing the overall configuration of a fuel cell humidifier
FIG. 9 shows the present invention.Reference example 3Schematic diagram showing the overall configuration of a fuel cell humidifier
FIG. 10 shows the present invention.Reference example 4Schematic diagram showing the overall configuration of a fuel cell humidifier
FIG. 11 shows the present invention.Reference Example 5Schematic diagram showing the overall configuration of a fuel cell humidifier
FIG. 12 shows the present invention.Reference Example 6Schematic diagram showing the overall configuration of a fuel cell humidifier
FIG. 13 shows the present invention.Reference Example 7Schematic diagram showing the overall configuration of a fuel cell humidifier
FIG. 14 shows the present invention.Reference Example 8Schematic diagram showing the overall configuration of a fuel cell humidifier
[Explanation of symbols]
  1 Fuel cell
  2 Pump
  3 Cooling water passage A
  4 Cooling section
  5 Cooling water passage B
  6 Humidifier
  7 Hot water flow path
  8 Cooling water passage C
  9 Moisture permeable membrane
  10 Air supply flow path
  11 Exhaust flow path
  12 Blower
  13 Air passage
  14 Hydrogen cylinder
  15 Fuel passage
  16 Exhaust passage
  17 Exhaust gas passage
  18a, 18b Single unit
  19 Support
  20 Ribs
  21 Wall surface
  22 Partition plate
  23 Air inlet
  23a-23c Air inlet
  24 Air outlet
  24a-24c Air outlet
  25 Wall A
  26 Partition A
  27 Exhaust inlet
  27a-27c Exhaust inlet
  28 Exhaust outlet
  28a-28c Exhaust outlet
  29 traps
  30 Flow of exhaust air
  31 Flow of supply air
  32 Flow of hot water
  33A First air supply passage
  33B Second air supply passage
  34 Exhaust flow path B
  35 Wall B
  36 Partition B
  37 Supply Air Flow B
  38 Exhaust flow path B
  39 Water reservoir
  40 Wall C
  41 Partition C
  42 dripping
  43 Flow of exhaust air B
  44 Hot water flow path B
  45 Hot water flow B
  46 Exhaust flow path C
  48 Exhaust flow path D
  49 Water reservoir B
  50 connecting passage
  51 Humidified water flow path
  52 Supply Source
  53 Exhaust air passage
  54 Moisture supply channel
  55 Condenser
  56 Water circuit
  57 pump
  58 Unevenness
  59 Air branch
  60 Pump B
  61 Vibration membrane
  62 Blower B

Claims (8)

A fuel electrode and an oxidant electrode disposed on both sides of the solid polymer membrane;
A fuel cell having a cooling section for flowing cooling water;
A moisture permeable membrane that is permeable to water vapor;
An air supply channel that is provided on the first main surface of the moisture permeable membrane and flows supply air;
An exhaust passage for passing exhaust gas from the oxidant electrode of the fuel cell provided on the second main surface of the moisture permeable membrane;
A humidifier comprising: a hot water flow path for heating exhaust gas from the oxidant electrode of the fuel cell supplied to the exhaust flow path;
A blower for supplying air to the air supply passage;
A first cooling water channel connecting the cooling unit and the hot water unit;
A second cooling water channel connecting the warm water part and the cooling part,
The cooling water is heated by the heat generated in the fuel cell in the cooling unit, and circulates in the order of the cooling unit, the first cooling water passage, the hot water passage, the second cooling water passage ,
The exhaust flow path is formed so that the exhaust air flows under gravity or in a horizontal direction and does not include an upward flow direction,
The direction of the flow of exhaust air flowing through the exhaust flow path is opposite to the direction of the flow of supply air flowing through the supply air flow path,
The direction of the flow of warm water flowing through the warm water channel is a direction opposite to the direction of the flow of supply air, and flows in a zigzag shape in the vertical direction.
Fuel cell system.  2. The water recovery means for recovering water contained in the exhaust gas from the oxidant electrode of the fuel cell is provided, and the water recovered by the water recovery means is heated by the hot water channel. The fuel cell system described in 1.  The fuel cell system according to claim 2, wherein the moisture recovery means is a trap.  3. The fuel cell system according to claim 2, wherein the moisture recovery unit includes an air / water separator, and a water retention part is provided below the air / water separator. 4.  The humidifier has a configuration in which one or a plurality of units in which the moisture permeable membrane, the air supply channel, the exhaust channel, and the hot water channel are integrated are stacked. The fuel cell system according to claim 1.  The fuel cell system according to claim 2, wherein the hot water channel is disposed adjacent to the moisture recovery means.  The fuel cell system according to claim 2, wherein the moisture recovery means is a trap provided in the exhaust passage connected to an exhaust passage, and the trap is formed in common for a plurality of units.  The fuel cell system according to claim 2, wherein the moisture recovery means is one or a plurality of traps arranged in the exhaust flow path, and the traps are formed in each of the plurality of units.

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