Water electrolysis system

Patent metadata

Field	Value
Publication number	US-2024240337-A1
Application number	US-202318515711-A
Country	US
Kind code	A1
Filing date	Nov 21, 2023
Priority date	Jan 12, 2023
Publication date	Jul 18, 2024
Grant date	—

Abstract

Provided is a water electrolysis system that obtains hydrogen by water electrolysis with a water electrolysis cell, the water electrolysis system including a water electrolysis stack having a plurality of the water electrolysis cells, a water supply side passage that supplies water to the water electrolysis stack, a hydrogen side passage that discharges the hydrogen obtained in the water electrolysis stack from the water electrolysis stack, a plurality of voltage sensors that measures voltages for the respective water electrolysis cells or for each group of the water electrolysis cells, and a control device configured to acquire a voltage from each of the voltage sensors, determine whether the voltage is lower than a predetermined value and notify the water electrolysis cell has a failure when it is determined that the voltage is lower than a predetermined value.

First claim

What is claimed is:

1 . A water electrolysis system that obtains hydrogen by water electrolysis with a water electrolysis cell, the water electrolysis system comprising:
a water electrolysis stack having a plurality of water electrolysis cells; a water supply side passage that supplies water to the water electrolysis stack; a hydrogen side passage that discharges the hydrogen obtained in the water electrolysis stack from the water electrolysis stack; a plurality of voltage sensors that measures voltages for the respective water electrolysis cells or for each group of the water electrolysis cells; and a control device, wherein the control device is configured to acquire a voltage from each of the voltage sensors, determine whether the voltage is lower than a predetermined value and notify that the water electrolysis cell has a failure when it is determined that the voltage is lower than the predetermined value.

2 . The water electrolysis system according to claim 1 , wherein the predetermined value is a voltage value obtained from an equivalent circuit of the water electrolysis cell.

3 . The water electrolysis system according to claim 1 , wherein:
the control device is configured to determine whether the voltage is lower than the predetermined value at a start of operation of the water electrolysis system; the predetermined value is a normal water electrolysis cell voltage corresponding to a current acquired in advance; and the control device compares the normal water electrolysis cell voltage with the voltage obtained from the voltage sensor, and determines that a short-circuit abnormality has occurred in the water electrolysis cell when the voltage is lower than an allowable voltage.

4 . The water electrolysis system according to claim 1 , wherein:
the control device is configured to determine whether the voltage is lower than the predetermined value during a steady operation of the water electrolysis system; the predetermined value is a lower limit of a width of an I-V characteristic of the water electrolysis cell that is acquired in advance; and the control device is configured to determine that a short-circuit abnormality has occurred in the water electrolysis cell when a voltage lower than the lower limit of the width of the I-V characteristic is detected.

5 . The water electrolysis system according to claim 4 , wherein:
the control device is configured to stop an operation of the water electrolysis system when a voltage higher than a predetermined threshold is detected; and the predetermined threshold is a value higher than an upper limit of the width of the I-V characteristic.

6 . The water electrolysis system according to claim 5 , wherein the control device is configured to continue the operation of the water electrolysis system when a voltage below the predetermined threshold and above the upper limit of the width of the I-V characteristic is detected.

7 . The water electrolysis system according to claim 3 , wherein the control device is configured to stop the operation of the water electrolysis system when it is determined that the short-circuit abnormality occurs in the water electrolysis cell.

Assignees

• Toyota Motor Co Ltd

Inventors

• Kitamura Nobuyuki

Classifications

• C25B9/23

  comprising ion-exchange membranes in or on which electrode material is embedded · CPC title

• C25B15/023 Primary

  Measuring, analysing or testing during electrolytic production · CPC title

• C25B1/04 Primary

  by electrolysis of water · CPC title

• C25B9/70 Primary

  Assemblies comprising two or more cells · CPC title

• Y02E60/36

  Hydrogen production from non-carbon containing sources, e.g. by water electrolysis · CPC title