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EP-4219792-B1 - COMPRESSION DEVICE

EP4219792B1EP 4219792 B1EP4219792 B1EP 4219792B1EP-4219792-B1

Inventors

  • KAKUWA, Takashi
  • KITA, HIROMI
  • SAKAI, OSAMU

Dates

Publication Date
20260506
Application Date
20210715

Claims (12)

  1. A compression apparatus (100) comprising: at least one compression unit (10) including an electrolyte membrane (21), an anode (AN) provided on a first principal surface of the electrolyte membrane (21), a cathode (CA) provided on a second principal surface of the electrolyte membrane (21), an anode separator (29B) stacked on the anode (AN), and a cathode separator (29A) stacked on the cathode (CA); a voltage applier (102) that applies a voltage between the anode (AN) and the cathode (CA); an anode end plate (16) provided on the anode separator (29B) located at a first end in a direction of stacking; a cathode end plate (15) provided on the cathode separator (29A) located at a second end in the direction of stacking; an insulating plate (13) provided between the cathode end plate (15) and the cathode separator (29A) located at the second end; and first and second plates (44A, 44B) provided between the insulating plate (13) and the cathode separator (29A) located at the second end, wherein the compression apparatus (100) causes, by using the voltage applier (102) to apply a voltage, protons taken out from an anode fluid that is supplied to the anode (AN) to move to the cathode (CA) via the electrolyte membrane (21) and produces compressed hydrogen, the first plate (44A) has formed therein a first space (SC) in which to store a cathode gas containing the compressed hydrogen, and the second plate (44B) is provided with a first manifold (136) through which the cathode gas flows and a first communicating path (138) through which to lead, to the first space (SC), the cathode gas having flowed in from the first manifold (136).
  2. The compression apparatus (100) according to claim 1, wherein the first plate (44A) and the second plate (44B) are integrated with each other by surface joining.
  3. The compression apparatus (100) according to claim 1 or 2, further comprising a third plate (46) provided between the anode end plate (16) and the anode separator (29B) located at the first end, wherein the third plate (46) has formed therein a second space (SA) in which to store a cathode gas containing the compressed hydrogen, and the anode separator (29B) located at the first end is provided with a second manifold (35) through which the cathode gas flows and a second communicating path (37) through which to lead, to the second space (SA), the cathode gas having flowed in from the second manifold (35).
  4. The compression apparatus (100) according to claim 3, wherein the third plate (46) and the anode separator (29B) located at the first end are integrated with each other by surface joining.
  5. The compression apparatus (100) according to claim 3 or 4, wherein the cathode separator (29A) has formed therein a third space (S) in which to store a cathode gas containing the compressed hydrogen, the anode separator (29B) is provided with a third manifold (36) through which the cathode gas flows and a third communicating path (38) through which to lead, to the third manifold (36), the cathode gas having flowed in from the third space (S), the first space (SC), the second space (SA), and the third space (S) are identical in shape to one another, and the first communicating path (138), the second communicating path (37), and the third communicating path (38) are identical in shape to one another.
  6. The compression apparatus (100) according to claim 5, wherein the anode separator (29B) and the cathode separator (29A) are integrated with each other by surface joining.
  7. The compression apparatus (100) according to claim 5 or 6, wherein the first plate (44A), the second plate (44B), the third plate (46), the anode separator (29B), and the cathode separator (29A) are each constituted by SUS316L.
  8. The compression apparatus (100) according to any one of claims 3 to 7, wherein at least one selected from the group consisting of the first plate (44A), the second plate (44B), the third plate (46), and the anode separator (29B) located at the first end is used also as a current collector.
  9. The compression apparatus according to claim 1 or 2, wherein an insulative elastic body or solid is provided in the first space (SC).
  10. The compression apparatus (100) according to claim 3 or 4, wherein an insulative elastic body or solid is provided in the second space (SA).
  11. The compression apparatus (100) according to claim 3 or 4, wherein an anode fluid flow channel (30) through which the anode fluid flows is provided in a surface of the anode separator (29B) located at the first end opposite to a surface of the anode separator (29B) located at the first end in which the second communicating path (37) is provided, and the anode fluid flow channel (30) is not provided in a surface of the second plate (44B) opposite to a surface of the second plate (44B) in which the first communicating path (138) is provided.
  12. The compression apparatus (100) according to claim 3 or 4, wherein a cooling flow channel (60) through which a cooling medium flows is provided in a surface of the anode separator (29B) located at the first end in which the second communicating path (37) is provided, and the cooling flow channel (60) is not provided in a surface of the second plate (44B) in which the first communicating path (138) is provided.

Description

Technical Field The present disclosure relates to a compression apparatus. Background Art In recent years, due to environmental problems such as global warming and energy problems such as depletion of oil resources, hydrogen has drawn attention as a clean alternative energy source that replaces fossil fuels. Hydrogen is expected to serve as clean energy, as it basically produces only water even at the time of combustion, does not discharge carbon dioxide, which is responsible for global warming, and hardly discharges nitrogen oxides or other substances. Further, as devices that utilize hydrogen as a fuel with high efficiency, fuel cells are being developed and becoming widespread for use in automotive power supplies and in-house power generation. For example, for use as a fuel in a fuel-cell vehicle, hydrogen is in general compressed into a high-pressure state of several tens of megapascals and stored in an in-vehicle hydrogen tank. Moreover, such high-pressure hydrogen is obtained, in general, by compressing low-pressure (normal pressure) hydrogen with a mechanical compression apparatus. Incidentally, in a hydrogen-based society to come, there is demand for technological development that makes it possible to, in addition to producing hydrogen, store hydrogen at high densities and transport or utilize hydrogen in small amounts and at low cost. In particular, hydrogen-supply infrastructures need to be built to expedite the widespread use of fuel cells, and for stable supply of hydrogen, various suggestions are made for the production, purification, and high-density storage of high-purity hydrogen. Under such circumstances, for example, NPL 1 proposes a high-differential-pressure water electrolysis apparatus (hereinafter referred to as "water electrolysis apparatus") in which water is separated into its hydrogen and oxygen components through electrolysis and high-pressure hydrogen is generated from low-pressure hydrogen via an electrolyte membrane. In order to generate hydrogen and oxygen through the electrolysis of water, the water electrolysis apparatus has disposed therein a solid polymer electrolyte membrane, an anode catalyst layer and a cathode catalyst layer that are provided on both surfaces of the solid polymer electrolyte membrane, and an anode feeder and a cathode feeder that are provided on both sides of these catalyst layers. It should be noted that a stack of a cathode including a cathode catalyst layer and a cathode feeder, an electrolyte membrane, and an anode including an anode catalyst layer and an anode feeder is referred to as "membrane-electrode assembly" (hereinafter abbreviated as "MEA"). Moreover, a water electrolysis cell of NPL 1 is constituted by an MEA, an anode separator and a resin frame that include a normal-pressure flow channel through which to supply water, discharge redundant water, and pass oxygen, and a cathode separator including a high-pressure gas flow channel through which to discharge high-pressure hydrogen. Further, in the water electrolysis apparatus, a plurality of the water electrolysis cells are stacked according to the amount of high-pressure hydrogen that is generated at a cathode, and terminals through which to apply a voltage are provided at both ends of the stack in a direction of stacking, whereby an electric current can be passed through the water electrolysis cell and water is supplied to the anode feeder. Then, on an anode side of the MEA, the water is electrolyzed, whereby protons are generated. The protons move toward the cathode by passing through the electrolyte membrane and recombine with electrons at the cathode feeder, whereby high-pressure hydrogen is generated. Then, the hydrogen is discharged from the water electrolysis apparatus via the high-pressure gas flow channel provided in the cathode separator. Meanwhile, oxygen generated at the anode and redundant water are discharged from the water electrolysis apparatus via the normal-pressure flow channel provided in the anode separator and in the resin frame. Note here that the water electrolysis apparatus, which compresses hydrogen obtained through water electrolysis, is high in hydrogen gas pressure at the cathode feeder. This causes the separators or other members to deform, whereby there is a possibility of an increase in contact resistance between members constituting the water electrolysis cell. To address this problem, NPL 1 proposes a structure in the water electrolysis apparatus in which a fastening member (bolt) is used to cause a stack including a plurality of the water electrolysis cells to be brought into close contact by end plates (both end plates). Further, an enclosed space is present between the upper end plate and a separator corresponding to an upper end of the stack, and this enclosed space has high-pressure hydrogen introduced thereinto. Furthermore, this enclosed space has an elastic body (spring) provided therein. The foregoing configuration makes it possible to, even if the