Water electrolysis system and water level error calculation apparatus

Patent metadata

Field	Value
Publication number	US-2021261446-A1
Application number	US-202117174294-A
Country	US
Kind code	A1
Filing date	Feb 11, 2021
Priority date	Feb 21, 2020
Publication date	Aug 26, 2021
Grant date	—

Abstract

A water electrolysis system includes: a water electrolyzer configured to electrolyze water to generate gas including oxygen and hydrogen; a gas-liquid separator configured to separate gas phase including hydrogen from liquid phase of the gas generated by the water electrolyzer; a water level detector configured to detect a water level in the gas-liquid separator; a pressure detector configured to detect a pressure of the gas phase in the gas-liquid separator; and a CPU and a memory coupled to the CPU. The CPU is configured to perform: calculating an error of the water level in the gas-liquid separator detected by the water level detector based on the pressure of the gas phase in the gas-liquid separator detected by the pressure detector.

First claim

What is claimed is:

1 . A water electrolysis system, comprising:
a water electrolyzer configured to electrolyze water to generate gas including oxygen and hydrogen; a gas-liquid separator configured to separate a gas phase including hydrogen from a liquid phase of the gas generated by the water electrolyzer; a water level detector configured to detect a water level in the gas-liquid separator; a pressure detector configured to detect a pressure of the gas phase in the gas-liquid separator; and a CPU and a memory coupled to the CPU, wherein the CPU is configured to perform:
calculating an error of the water level in the gas-liquid separator detected by the water level detector based on the pressure of the gas phase in the gas-liquid separator detected by the pressure detector.

2 . The water electrolysis system according to claim 1 , wherein
the CPU is configured to perform:
calculating the pressure of the gas phase in the gas-liquid separator based on an amount of hydrogen generated by the water electrolyzer and the water level in the gas-liquid separator detected by the water level detector; and
calculating the error of the water level in the gas-liquid separator detected by the water level detector based on the pressure of the gas phase calculated and the pressure of the gas phase detected by the pressure detector.

3 . The water electrolysis system according to claim 1 , further comprising:
a draining device configured to drain water in the gas-liquid separator, wherein the CPU is configured to perform:
correcting the water level in the gas-liquid separator detected by the water level detector based on the error of the water level calculated; and
controlling the draining device based on the water level corrected.

4 . The water electrolysis system according to claim 3 , wherein
the CPU is configured to perform:
controlling the draining device so as not to fill up nor empty out the gas-liquid separator.

5 . The water electrolysis system according to claim 1 , wherein
the water level detector is a weight sensor configured to detect the water level in the gas-liquid separator based on a weight of the gas-liquid separator.

6 . The water electrolysis system according to claim 5 , wherein
the gas-liquid separator includes a substantially cylindrical vessel, wherein the water level detector is configured to detect the water level in the vessel, wherein the pressure detector is configured to detect the pressure of the gas phase in the vessel, wherein the water level detector is disposed in contact with a bottom of the vessel.

7 . The water electrolysis system according to claim 1 , wherein
the gas-liquid separator is connected to a cathode side of the water electrolyzer and is connected to a back pressure valve set to a predetermined pressure, wherein the pressure of the gas phase in the gas-liquid separator increases in accordance with an amount of hydrogen generated on the cathode side of the water electrolyzer up to the predetermined pressure.

8 . The water electrolysis system according to claim 7 , wherein
the pressure detector is attached to a piping connecting the cathode side of the water electrolyzer and the gas-liquid separator.

9 . The water electrolysis system according to claim 1 , wherein
the water electrolyzer, the gas-liquid separator, the water level detector, and the pressure detector are housed in a single container.

10 . A water electrolysis system, comprising:
a water electrolyzer configured to electrolyze water to generate gas including oxygen and hydrogen; a gas-liquid separator configured to separate gas phase including hydrogen from liquid phase of the gas generated by the water electrolyzer; a water level detector configured to detect a water level in the gas-liquid separator; a pressure detector configured to detect a pressure of the gas phase in the gas-liquid separator; and a CPU and a memory coupled to the CPU, wherein the CPU is configured to function as:
an arithmetic unit configured to calculate an error of the water level in the gas-liquid separator detected by the water level detector based on the pressure of the gas phase in the gas-liquid separator detected by the pressure detector.

11 . The water electrolysis system according to claim 10 , wherein
the arithmetic unit is configured to calculate the pressure of the gas phase in the gas-liquid separator based on an amount of hydrogen generated by the water electrolyzer and the water level in the gas-liquid separator detected by the water level detector, and to calculate the error of the water level in the gas-liquid separator detected by the water level detector based on the pressure of the gas phase calculated and the pressure of the gas phase detected by the pressure detector.

12 . The water electrolysis system according to claim 10 , further comprising:
a draining device configured to drain water in the gas-liquid separator, wherein the CPU is configured to function as:
a drainage control unit configured to correct the water level in the gas-liquid separator detected by the water level detector based on the error of the water level calculated by the arithmetic unit, and to control the draining device based on the water level corrected.

13 . The water electrolysis system according to claim 12 , wherein
the drainage control unit is configured to control the draining device so as not to fill up nor empty out the gas-liquid separator.

14 . The water electrolysis system according to claim 10 , wherein
the water level detector is a weight sensor configured to detect the water level in the gas-liquid separator based on a weight of the gas-liquid separator.

15 . The water electrolysis system according to claim 14 , wherein
the gas-liquid separator includes a substantially cylindrical vessel, wherein the water level detector is configured to detect the water level in the vessel, wherein the pressure detector is configured to detect the pressure of the gas phase in the vessel, wherein the water level detector is disposed in contact with a bottom of the vessel.

16 . The water electrolysis system according to claim 10 , wherein
the gas-liquid separator is connected to a cathode side of the water electrolyzer and is connected to a back pressure valve set to a predetermined pressure, wherein the pressure of the gas phase in the gas-liquid separator increases in accordance with an amount of hydrogen generated on the cathode side of the water electrolyzer up to the predetermined pressure.

17 . The water electrolysis system according to claim 16 , wherein
the pressure detector is attached to a piping connecting the cathode side of the water electrolyzer and the gas-liquid separator.

18 . The water electrolysis system according to claim 10 , wherein
the water electrolyzer, the gas-liquid separator, the water level detector, and the pressure detector are housed in a single container.

19 . A water level error calculation apparatus configured to calculate a detection error of a water level in a gas-liquid separator, the water level error calculation apparatus comprising:
a water level detector configured to detect the water level in the gas-liquid separator; a pressure detector configured to detect a pressure of a gas phase in the gas-liquid separator; and a CPU and a memory coupled to the CPU, wherein the CPU is configured to perform:
calculating the detection error of the water level in the gas-liquid separator detected by the water level detector

Assignees

• Honda Motor Co Ltd

Inventors

• Asano Yuji
• Takeuchi Jun
• Aoki Kazuya

Classifications

• C25B9/77

  having diaphragms · CPC title

• C25B9/05

  Pressure cells · CPC title

• C25B1/04 Primary

  by electrolysis of water · CPC title

• Y02E60/36

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

• C25B15/02

  Process control or regulation · CPC title