JP2008140783A - Hydrogen dilution device of fuel cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hydrogen dilution device of a fuel cell which can dilute hydrogen into a sufficiently low concentration and has no fear of blocking a penetrating hole. <P>SOLUTION: The hydrogen diluting device of a fuel cell includes a stay room 2 where an anode offgas stays, an anode introducing passage 6 to introduce the anode offgas into the stay room 2, a cathode introducing passage 7 to introduce a cathode offgas into the stay room 2 and an offgas extracting passage 9 to extract the anode offgas and the cathode offgas. An opening 8 of the cathode introducing passage 7 and an opening 10 of the offgas extracting passage 9 are arranged almost facing each other and both of the openings 8, 10 are arranged close to each other with a space d. A bifurcating hole 11 can be arranged in the cathode introducing passage 7 to connect with the stay room 2. Furthermore, one of the opening end portions of the cathode introducing passage and the offgas extracting passage can be inserted into the other opening end portion with a space. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a hydrogen dilution device used for diluting hydrogen gas discharged from a fuel cell.

  When a fuel cell that generates power using hydrogen is installed in a vehicle or the like, the anode off-gas (hydrogen off-gas) that is discharged intermittently is diluted with the cathode off-gas so that the anode off-gas (hydrogen off-gas) is sufficiently low in the atmosphere. It is being released. For this reason, in a cathode offgas system such as a vehicle equipped with a fuel cell, a hydrogen diluter for mixing the anode offgas with the cathode offgas and discharging it to the outside of the vehicle has been provided.

For example, Patent Documents 1 and 2 include a cathode flow that has an anode flow path that opens into a container and guides the anode off gas into the container, and a communication hole that communicates with the inside of the container, and through which the cathode off gas flows. A hydrogen diluter for a fuel cell provided with a channel is disclosed. In such a hydrogen diluter, the anode off-gas or the anode off-gas mixed with a part of the cathode off-gas in the container is diluted by being gradually guided to the cathode flow path with the flow rate being limited by the communication hole, and eventually. It is designed to be discharged outside the vehicle. However, since the anode off-gas and cathode off-gas contain moisture and are led into the vessel, if the communication hole is formed to have a small diameter and the hydrogen concentration is diluted to a lower concentration, the small diameter communication hole is blocked by condensed water. There was a risk of causing it.
JP 2004-127666 A JP 2006-31998

  The present invention has been made in view of the above problems, and it is a main object of the present invention to provide a hydrogen diluter for a fuel cell that can dilute hydrogen to a sufficiently low concentration and has a low risk of blockage of communication holes. To do.

  In order to solve the above-mentioned problems, the invention according to claim 1 is characterized in that a residence chamber for retaining the anode off gas, an anode introduction passage for introducing the anode off gas to the residence chamber, and a cathode introduction passage for introducing the cathode off gas to the residence chamber. And a hydrogen diluter for a fuel cell comprising an anode off gas and an cathode off gas leading out path, and the opening of the cathode introducing path and the opening of the off gas leading path are substantially opposed to each other, and the openings are spaced from each other. A hydrogen diluter for a fuel cell, wherein the hydrogen diluter is disposed close to the fuel cell.

  According to a second aspect of the present invention, there is provided a residence chamber for retaining the anode off gas, an anode introduction passage for introducing the anode off gas to the residence chamber, a cathode introduction passage for introducing the cathode off gas to the residence chamber, and the anode off gas and the cathode off gas. A hydrogen diluter for a fuel cell having an off-gas lead-out path, wherein one open end of the cathode introduction path and the off-gas lead-out path is inserted with a gap at the other open end. It is a hydrogen diluter of a fuel cell.

  A third aspect of the present invention is the hydrogen diluter for a fuel cell according to the first or second aspect of the present invention, wherein the cathode introduction passage is provided with a diversion hole communicating with the staying chamber.

  According to the present invention, there is an effect that the risk of clogging due to freezing is reduced and hydrogen can be diluted to a sufficiently low concentration.

  The best mode for carrying out the present invention will be described based on the embodiment shown in FIGS.

  FIG. 1 is a longitudinal sectional view showing a hydrogen diluter 1 according to the first embodiment. The upper part of FIG. The container of the hydrogen diluter 1 is formed by joining the outer plates 4 and 5 so as to be substantially sealed at both open ends of the shell 3 that is a cylindrical body having an elliptical cross section, thereby forming a retention chamber 2. For the shell 3 and the outer plates 4, 5, any material and any shape such as a metal such as aluminum or a resin can be selected. Moreover, not only a shell and an outer plate but a residence chamber can be formed by arbitrary structures.

  An anode introduction path 6 that opens into the retention chamber 2 is provided through the outer plate 4. The anode introduction path 6 is connected to an anode system of a fuel cell system (not shown). The anode introduction path 6 can adopt any form capable of introducing the anode off gas into the residence chamber 2. Moreover, the retention chamber 2 can be provided in arbitrary places.

  A cathode introduction path 7 that opens into the residence chamber 2 passes through the outer plate 4 and is provided near the bottom of the residence chamber 2. An off-gas lead-out path 9 having an opening 10 that opens into the retention chamber 2 passes through the outer plate 5 so as to be close to and substantially opposed to each other so as to have a gap d between the opening 8 of the cathode introduction path 7. And provided near the bottom of the retention chamber 2. In this way, by arranging the openings 8 and 10 so as to be close to each other with a gap d so as to be substantially opposed to each other, the amount of off-gas guided from the residence chamber 2 to the off-gas outlet path 9 is limited. Can do. The gap d is appropriately adjusted in accordance with the anode off-gas discharge interval, pressure, hydrogen concentration, etc., but is at most equal to or less than the circle diameter equal to the cross-sectional area of the cathode introduction path 7 or off-gas lead-out path 8. It is desirable to be.

  The cathode introduction path 7 is provided with a flow dividing hole 11 which is a louvered hole protruding in the inner direction of the cathode introduction path 7. As a result, a part of the cathode off-gas is led into the container 2 and the rest passes through the opening 10 that is in close proximity to the opening 8 of the cathode introduction path 7, flows through the off-gas outlet path 9, and is eventually discharged outside the vehicle. In addition, separators 12 to 15 having communication portions (not shown) are provided in the retention chamber 2. As a result, a part of the cathode offgas introduced into the residence chamber 2 from the flow dividing hole 11 is sufficiently mixed with the anode offgas, so that the anode offgas is diluted.

  With the above configuration, the anode off-gas introduced into the residence chamber 2 is diluted with a part of the cathode off-gas in advance, and then the opening 8 of the cathode introduction path 7 and the opening 10 of the off-gas outlet path 9 Is gradually led from the gap d to the off gas lead-out path 9, and further diluted with the cathode off gas and discharged outside the vehicle. Accordingly, the hydrogen concentration can be made sufficiently low and discharged outside the vehicle. Further, the blockage due to freezing of the condensed water is less likely to occur than in the case where the gas flow rate is limited by the small diameter communication hole. Further, when condensed water is introduced into the retention chamber 2, it can be drained from the gap d. In this case, since the gap d is formed in a circumferential shape, it can be easily drained even when a large amount of condensed water is introduced. Moreover, the thermal expansion difference generated between the stay chamber 2 can be absorbed, and the durability can be improved.

  FIGS. 2A to 2D are diagrams schematically showing hydrogen diluters 1a to 1d according to modifications of the first embodiment. The same reference numerals are given to the same components as those in the first embodiment, and FIG. Description is omitted.

  As shown in FIG. 2 (a), the openings 8a and 10a may be provided so as to be inclined with respect to the flow direction of the cathode introduction path 7a and the off-gas outlet path 9a. Not only this example but an opening can be provided in arbitrary shapes. Further, as shown in FIG. 2 (b), the cathode introduction path 7b and the off-gas outlet path 9b may be disposed so as to be offset. Further, as shown in FIG. 2 (c), the cathode introduction path 7c and the offgas outlet path 9c may be disposed so as to be inclined with respect to each other. Moreover, you may provide so that a flow path may be curved. In the case of FIG. 2B and FIG. 2C, it is desirable to project the cathode introduction path in the direction of the flow path so that 50% or more of the projected area is projected to the opening of the off-gas outlet path. FIG. 2D shows an example in which a silencing function is added to the hydrogen diluter. A silencing chamber 16 formed by partitioning the inside of the container is filled with a sound absorbing material 16 such as glass wool, and a plurality of parts are disposed in a part of the off-gas outlet path. The small holes 17 are provided. An arbitrary silencing structure may be added as in this example, and for example, a gas-liquid separation function may be added.

  3 (a) to 3 (c) are diagrams schematically showing hydrogen diluters 1e to 1g according to modifications of the first embodiment. The same reference numerals are given to the same components as those in the first embodiment, and FIG. Description is omitted.

  FIG. 3 (a) shows the inside of the container partitioned by a separator 12e to form the cathode introduction path 7e and the staying chamber 2, and an off-gas outlet path by arranging a bowl-shaped member along a part of the container. 9e is formed. The cathode off gas is guided to the cathode introduction path 7e from the through hole 18 provided in the container, and the opening 8e is formed by a communicating portion provided in the separator 12e. Further, the opening 10e of the off-gas outlet path 9e is disposed so as to be close to the opening 8e so as to have a gap. FIG. 3 (b) shows that the interior of the container is partitioned by a separator 12f to form the retention chamber 2, and a bowl-shaped member is arranged along a part of the container to form the cathode introduction path 7f. is there. Further, the opening 10f of the off-gas outlet 9f is formed by a through hole provided in the container so as to be close to the opening 8f of the cathode introduction passage 7f so as to have a gap. FIG. 3C shows an off-gas lead-out path 9g divided into two. As shown in this example, a plurality of off-gas lead-out paths may be provided and provided close to each other so that each opening has a gap.

  As shown in FIGS. 3 (a) to 3 (c), the cathode introduction path and the off-gas lead-out path are not limited to a tubular one, for example, a bowl-shaped member disposed along a part of the container, The inside of the case can be arbitrarily formed such as a passage shape. These openings are not limited to pipe openings, and may be through holes provided in a case, a separator, or the like. In addition, although it is not necessary to provide a diversion hole like the modification shown in FIG. 2 and FIG. 3, you may provide similarly to Example 1. FIG. Moreover, the quantity and form of the flow dividing holes and separators can be arbitrarily set. Furthermore, a drainage hole may be provided in the offgas outlet path as appropriate.

  FIG. 4 is a longitudinal sectional view showing the hydrogen diluter 21 of the second embodiment, and the upper side of FIG. 4 is shown to be upward in the actual use state. Moreover, the same code | symbol is provided to the structure same as Example 1, and the description is abbreviate | omitted. A cathode introduction path 27 that opens into the retention chamber 2 passes through the outer plate 4 and is provided near the bottom of the retention chamber 2. Further, an off-gas outlet path 29 is provided in the vicinity of the bottom of the stay chamber 2 through the outer plate 5. The open end 28 of the cathode introduction path 27 is inserted into the open end 30 of the off-gas outlet path 29 so as to have a gap d. In addition, the opening end portion 28 is provided with a plurality of dot-like protrusions 31 for the purpose of preventing the opening end portions from interfering with each other to generate a hitting sound. The protrusion 31 does not need to be provided according to the insertion length 1, and a cushioning material such as a wire mesh may be provided instead of the protrusion 31. Further, the insertion length l can be appropriately adjusted according to the anode off-gas discharge interval, pressure, hydrogen concentration, and the like, as with the gap d. For the purpose of suppressing the pulsation of the anode off gas, a cylindrical cover 32 having a small hole 33 is provided so as to surround the opening end of the anode introduction path 6.

  With the configuration described above, the anode off-gas introduced into the residence chamber 2 is gradually turned off from the gap d between the opening end 28 of the cathode introduction path 27 and the opening end 30 of the off-gas outlet path 29. It is led to the lead-out path 29, and after being diluted with the cathode off gas, it is discharged outside the vehicle. Thereby, the same effect as Example 1 can be exhibited. 2 and 3 can also be applied to the second embodiment.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and design changes within a range that does not depart from the spirit of the present invention are included in the present invention.

1 is a longitudinal sectional view showing a hydrogen diluter according to Embodiment 1 of the present invention. FIG. 6 is a schematic diagram illustrating a modification of the first embodiment. FIG. 6 is a schematic diagram illustrating a modification of the first embodiment. The longitudinal cross-sectional view which shows the hydrogen diluter of Example 2 of this invention.

Explanation of symbols

1, 1a to 1g, 21 Hydrogen diluter 2 Residence chamber 6 Anode introduction path 7, 7a to 7g, 27 Cathode introduction path 8, 8a to 8g Open 28 Open end 9, 9a to 9g, 29 Off-gas lead-out path 10, 10a -10g Opening 30 Opening end 11 Dividing hole

Claims (3)

  A residence chamber for retaining the anode off-gas, an anode introduction passage for introducing the anode off-gas to the residence chamber, a cathode introduction passage for introducing the cathode off-gas to the residence chamber, and an off-gas outlet passage for deriving the anode off-gas and the cathode off-gas. In the hydrogen diluter of a fuel cell, the opening of the cathode introduction path and the opening of the off-gas outlet path are substantially opposed to each other, and the both openings are arranged close to each other so as to have a gap. Hydrogen diluter.   A residence chamber for retaining the anode off-gas, an anode introduction passage for introducing the anode off-gas to the residence chamber, a cathode introduction passage for introducing the cathode off-gas to the residence chamber, and an off-gas outlet passage for deriving the anode off-gas and the cathode off-gas. A hydrogen diluter for a fuel cell, wherein one open end of the cathode introduction path and the off-gas lead-out path is inserted with a gap at the other open end.   3. The hydrogen diluter for a fuel cell according to claim 1, wherein a diversion hole communicating with the staying chamber is provided in the cathode introduction path.

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