# US 2024/0200214 A1 · Water electrolysis apparatus

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- Number: US 2024/0200214 A1
- Document ID: US20240200214A1
- Status: Published application
- Kind: A1
- Application number: 18/485,406
- Filed: 2023-10-12
- Published: 2024-06-20
- Earliest claimed: 2022-12-20
- Assignees: Toyota Jidosha Kabushiki Kaisha
- Applicants: Toyota Jidosha Kabushiki Kaisha
- Inventors: Makoto Mori; Nobuyuki Kitamura
- Web page: https://patentgrep.com/patent/US20240200214A1

## CPC

- C25B 15/033: Conductivity
- C25B 1/04: by electrolysis of water
- C25B 9/73: of the filter-press type
- C25B 9/77: having diaphragms
- C25B 15/02: Process control or regulation
- C25B 15/08: Supplying or removing reactants or electrolytes; Regeneration of electrolytes
- C25B 15/087: {Recycling of electrolyte to electrochemical cell}
- Y02E 60/36: Hydrogen production from non-carbon containing sources, e.g. by water electrolysis
- C25B: ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR (anodic or cathodic protection C23F13/00; single-crystal growth C30B)
- Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION

## Abstract

A device for supplying water to a water electrolysis cell and supplying a voltage to obtain hydrogen and oxygen, the device comprising: a water electrolysis stack in which a water electrolysis cell is laminated; a water supply side path having a pipe for supplying water to the water electrolysis stack; a hydrogen side path having a pipe for recovering hydrogen generated from the water electrolysis stack; and a water recirculation path having a pipe for returning water from the hydrogen side path to the water supply side path; and a conductivity meter for measuring conductivity of water flowing through the pipe, a valve for draining water from the pipe, and a controller for performing control for draining water from the valve based on a measured value of the conductivity meter, in the water supply side path and the water recirculation path.

## Claims

### Claim 1

A water electrolysis apparatus that supplies water to a water electrolysis cell and applies a voltage to obtain hydrogen and oxygen, the water electrolysis apparatus comprising:
a water electrolysis stack in which the water electrolysis cells are laminated;
a water supply side path including a pipe through which water is supplied to the water electrolysis stack;
a hydrogen side path including a pipe through which hydrogen generated from the water electrolysis stack is recovered; and
a water recirculation path including a pipe through which water from the hydrogen side path is returned to the water supply side path, wherein:
in each of the water supply side path and the water recirculation path, a conductivity meter that measures conductivity of water flowing through the pipe, a valve from which water from the pipe is drained, and a controller are provided; and
the controller performs control to drain water from the valve based on a measured value of the conductivity meter.

### Claim 2 (depends on 1)

The water electrolysis apparatus according to claim 1, wherein in the water electrolysis apparatus, the controller performs control using the conductivity meter and the valve provided in the water supply side path in an operation in which water electrolysis is not performed in the water electrolysis stack, and performs control using the conductivity meter and the valve provided in the water recirculation path in an operation in which water electrolysis is performed in the water electrolysis stack.

### Claim 3 (depends on 2)

The water electrolysis apparatus according to claim 2, wherein in the operation in which the water electrolysis is performed in the water electrolysis stack, the controller acquires a water consumption flow rate due to the water electrolysis, calculates an accompanying water amount to the hydrogen side path, and determines an amount of the drained water based on the accompanying water amount.