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EP-4332201-B1 - HYDROGEN SUPPLY SYSTEM

EP4332201B1EP 4332201 B1EP4332201 B1EP 4332201B1EP-4332201-B1

Inventors

  • INAGAKI, Ryohei
  • IIZUKA, HIDEHIRO
  • KANI, YUUKO
  • SASAKI, TAKASHI
  • MIZUKAMI, TAKAAKI
  • ISHIDA, NAOYUKI
  • FUJITA, SHINJI
  • WATANABE, AYUMI

Dates

Publication Date
20260506
Application Date
20210428

Claims (7)

  1. A hydrogen supply system (100) comprising: a hydrogen production unit (101) configured to produce hydrogen; a hydrogen boosting unit (102) configured to boost a pressure of the hydrogen produced by the hydrogen production unit (101) to a pressure at which the hydrogen can be supplied to a gas grid (901); a grid gas lead-in unit (103) configured to lead grid gas from the gas grid (901); a hydrogen concentration adjustment unit (104) configured to adjust mixed gas to have a hydrogen concentration equal to or lower than an allowable hydrogen concentration specified in the gas grid (901); and a mixed gas return unit (105) configured to supply the mixed gas to the gas grid, characterised in that the hydrogen concentration adjustment unit (104) is configured to adjust the hydrogen concentration of the mixed gas by changing a grid gas flow rate.
  2. The hydrogen supply system (100) according to claim 1, wherein at least blend gas of natural gas and hydrogen flows through the gas grid (901).
  3. The hydrogen supply system (100) according to claim 1 or 2, wherein the hydrogen production unit (101) is configured to produce hydrogen by any one of a method of electrolysis of water using electric power generated by renewable energy, a method of reforming natural gas, and a method of producing hydrogen by gasifying coal and causing shift reaction.
  4. The hydrogen supply system (100) according to claim 1 or 2, wherein the grid gas lead-in unit (103) includes: a grid gas hydrogen concentration measurement unit (1031) configured to measure a hydrogen concentration in grid gas; a grid gas hydrogen concentration communication unit (1032) configured to transmit data of the hydrogen concentration in the grid gas to the hydrogen concentration adjustment unit (104); a grid gas flow rate reception unit (1033) configured to receive a grid gas flow rate calculated by the hydrogen concentration adjustment unit (104); a grid gas flow rate adjustment unit (1034) configured to adjust and leads the grid gas; and a grid gas supply unit (1035) configured to supply the grid gas to the hydrogen concentration adjustment unit (104).
  5. The hydrogen supply system (100) according to any one of claims 1 to 4, wherein the hydrogen concentration adjustment unit (104) includes: a grid gas hydrogen concentration reception unit (1041) configured to receive the hydrogen concentration in the grid gas from the grid gas lead-in unit (103); a produced hydrogen flow rate measurement unit (1042) configured to measure a flow rate of the hydrogen produced by the hydrogen production unit (101); a grid gas flow rate calculation unit (1043) configured to calculate a grid gas flow rate such that the mixed gas has a hydrogen concentration equal to or lower than the allowable hydrogen concentration specified in the gas grid (901) from the flow rate of the hydrogen produced by the hydrogen production unit (101); a grid gas flow rate command unit (1044) configured to command the grid gas flow rate calculated by the grid gas flow rate calculation unit (1043); a gas mixing unit (1045) configured to mix a designated amount of the grid gas supplied from the grid gas lead-in unit (103) and the hydrogen produced by the hydrogen production unit (101); and a mixed gas supply unit (1046) configured to supply the mixed gas mixed by the gas mixing unit (1045) to the mixed gas return unit (105).
  6. The hydrogen supply system (100) according to claim 5, wherein the mixed gas return unit (105) includes: a mixed gas flow rate measurement unit (1051) configured to measure a flow rate of the mixed gas; and a grid gas flow rate balance management unit (1052) configured to manage balance of the grid gas by comparing a grid gas flow rate in the mixed gas obtained by subtracting the produced hydrogen flow rate measured by the produced hydrogen flow rate measurement unit (1042) from the mixed gas flow rate measured by the mixed gas flow rate measurement unit (1051) with the grid gas flow rate commanded by the grid gas flow rate command unit (1044).
  7. The hydrogen supply system (100) according to claim 6, wherein the mixed gas return unit (105) further includes a return gas calorimetry unit (1054) configured to measure an amount of heat of hydrogen in the return gas.

Description

Technical Field The present invention relates to a hydrogen supply system capable of supplying hydrogen at equal to or lower than a hydrogen concentration specified in a gas grid when hydrogen is supplied to the gas grid in which mixing of hydrogen is allowed. Background Art Hydrogen as opposed to fossil fuels is clean energy that does not emit carbon dioxide during combustion. Thus, attention has been paid as one of clean energy for countermeasures against global warming, and technological development related to production, transportation, and utilization of hydrogen has been advanced. Under such circumstances, it has been proposed to supply hydrogen produced by electrolysis of water using renewable energy, or the like, reforming of natural gas, or the like, to a gas pipeline in which mixing of hydrogen is allowed. In this case, it is assumed that a hydrogen concentration becomes equal to or higher than a hydrogen concentration specified in a gas grid in the vicinity of a hydrogen supply point, and an amount of hydrogen desired to be supplied cannot be supplied. In addition, in order to supply hydrogen to a gas grid, PTL 1 below proposes a method of mixing hydrogen with fossil fuel gas such as LP gas or natural gas so as to satisfy city gas standards and supplying the mixture to the gas grid. PTL 2 discloses systems and methods for distributing hydrogen. A fuel is supplied in a pipe, and a stream comprising hydrogen is injected into the pipe. Hydrogen is extracted from the pipe downstream of the injection point. Citation List Patent Literature PTL 1: JP 2006-169357 APTL 2: US 2004/112427 A1 Summary of Invention Technical Problem In the invention described in PTL 1, fossil fuel gas is newly mixed in order to supply hydrogen. Thus, in the invention described in PTL 1, supply cost is greatly increased. It is therefore an object of the present invention to prevent increase in cost and prevent a hydrogen concentration from exceeding a hydrogen concentration specified value provided in a gas grid when supplying hydrogen produced as clean energy to the gas grid. Solution to Problem In order to solve the above problems, a hydrogen supply system of the present invention is set forth in claim 1. Other means will be described in description of embodiments. Advantageous Effects of Invention According to the present invention, it is possible to supply hydrogen while preventing increase in cost and preventing a hydrogen concentration from exceeding a hydrogen concentration specified value provided in a gas grid when supplying hydrogen produced as clean energy to the gas grid. Brief Description of Drawings [FIG. 1] FIG. 1 is an explanatory diagram of a hydrogen supply system for explaining a first embodiment.[FIG. 2] FIG. 2 is an explanatory diagram of a hydrogen supply system for explaining a second embodiment.[FIG. 3] FIG. 3 is an explanatory diagram of a hydrogen supply system for explaining a third embodiment.[FIG. 4] FIG. 4 is an explanatory diagram of a hydrogen supply system for explaining a fourth embodiment. Description of Embodiments Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that the same components are denoted by the same reference numerals, and in a case where description thereof overlaps, the description thereof may be omitted. In addition, the present invention is not limited to the following embodiments. <<First embodiment>> FIG. 1 is an explanatory diagram for explaining a hydrogen supply system 100 according to a first embodiment. The hydrogen supply system 100 described in the first embodiment includes a hydrogen production unit 101, a hydrogen boosting unit 102, a grid gas lead-in unit 103, a hydrogen concentration adjustment unit 104, and a mixed gas return unit 105. The hydrogen supply system 100 is connected to a gas grid 901 to supply hydrogen to the gas grid 901. At least blend gas of natural gas and hydrogen flows through the gas grid 901. The blend gas may be referred to as mixed gas. The hydrogen production unit 101 produces hydrogen. The hydrogen boosting unit 102 boosts a pressure of the hydrogen produced by the hydrogen production unit 101 to a pressure at which the hydrogen can be supplied to the gas grid 901 and supplies the hydrogen to the hydrogen concentration adjustment unit 104. The grid gas lead-in unit 103 leads grid gas from the gas grid 901 and supplies the grid gas to the hydrogen concentration adjustment unit 104. The hydrogen concentration adjustment unit 104 adjusts the mixed gas to have a hydrogen concentration equal to or lower than an allowable hydrogen concentration specified in the gas grid 901. The mixed gas return unit 105 supplies the mixed gas adjusted by the hydrogen concentration adjustment unit 104 to the gas grid 901. Here, the grid gas lead-in unit 103 and the mixed gas return unit 105 are connected to the gas grid 901. In the gas grid 901, for example, mixed gas (grid gas) of natural gas an