Hydrogen concentration sensor

Patent metadata

Field	Value
Publication number	US-2020158683-A1
Application number	US-201816198044-A
Country	US
Kind code	A1
Filing date	Nov 21, 2018
Priority date	Nov 21, 2018
Publication date	May 21, 2020
Grant date	—

Abstract

An illustrative example hydrogen concentration sensor includes a hydrogen chamber configured to isolate hydrogen within the hydrogen chamber from gas outside the hydrogen chamber. A hydrogen evolving electrode is configured to generate pure hydrogen within the hydrogen chamber. A reference electrode is situated to be exposed to pure hydrogen within the hydrogen chamber. A detection electrode associated with the reference electrode is situated to be exposed to gas outside the hydrogen chamber. The detection electrode is configured to provide an indication of a concentration of hydrogen in the gas outside the hydrogen chamber.

First claim

We claim:

1 . A hydrogen concentration sensor, comprising:
a hydrogen chamber configured to isolate hydrogen within the hydrogen chamber from gas outside the hydrogen chamber; a hydrogen evolving electrode configured to generate pure hydrogen within the hydrogen chamber; a reference electrode situated to be exposed to pure hydrogen within the hydrogen chamber; and a detection electrode associated with the reference electrode, the detection electrode being situated to be exposed to gas outside the hydrogen chamber, the detection electrode being configured to provide an indication of a concentration of hydrogen in the gas outside the hydrogen chamber.

2 . The hydrogen concentration sensor of claim 1 , wherein the hydrogen evolving electrode introduces a positive pressure within the hydrogen chamber.

3 . The hydrogen concentration sensor of claim 2 , wherein
the hydrogen chamber includes a vent; and the positive pressure within the hydrogen chamber prevents the gas outside the hydrogen chamber from entering the hydrogen chamber through the vent.

4 . The hydrogen concentration sensor of claim 1 , wherein
the hydrogen evolving electrode is part of a first electrochemical cell; and the reference electrode and the detection electrode are part of a second electrochemical cell.

5 . The hydrogen concentration sensor of claim 4 , wherein
the first electrochemical cell comprises a first matrix containing an electrolyte; the first electrochemical cell comprises a hydrogen oxidizing electrode; the first matrix is at least partially situated between the hydrogen oxidizing electrode and the hydrogen evolving electrode; and a voltage is applied across the hydrogen evolving electrode and the hydrogen oxidizing electrode.

6 . The hydrogen concentration sensor of claim 5 , wherein the electrolyte in the first matrix comprises phosphoric acid.

7 . The hydrogen concentration sensor of claim 4 , wherein the second electrochemical cell includes a second matrix at least partially situated between the reference electrode and the detection electrode; and
a voltage across the reference electrode and the detection electrode provides the indication of the concentration of hydrogen in the gas outside the hydrogen chamber.

8 . The hydrogen concentration sensor of claim 7 , wherein the second matrix contains phosphoric acid.

9 . The hydrogen concentration sensor of claim 1 , wherein positive pressure within the hydrogen chamber prevents the gas outside the hydrogen chamber from entering the hydrogen chamber.

10 . The hydrogen concentration sensor of claim 1 , wherein no current passes at the reference electrode.

11 . A method of determining a concentration of hydrogen in a gas, the method comprising:
evolving pure hydrogen from the gas using a hydrogen evolving electrode; at least temporarily containing the evolved pure hydrogen in a hydrogen chamber; exposing a reference electrode to the pure hydrogen in the hydrogen chamber; exposing a detection electrode to the gas; and determining a voltage across the reference electrode and the detection electrode as an indication of the concentration of hydrogen in the gas.

12 . The method of claim 11 , wherein the hydrogen evolving electrode is associated with a hydrogen oxidizing electrode and the method comprises
exposing a hydrogen oxidizing electrode to the gas; and applying a voltage across the hydrogen oxidizing electrode and the hydrogen evolving electrode.

13 . The method of claim 11 , comprising
introducing a positive pressure within the hydrogen chamber; and isolating the pure hydrogen in the hydrogen chamber from the gas using the positive pressure.

14 . The method of claim 13 , wherein the hydrogen evolving electrode introduces the positive pressure within the hydrogen chamber.

15 . The method of claim 13 , wherein
the hydrogen chamber includes a vent; and the positive pressure within the hydrogen chamber prevents the gas outside the hydrogen chamber from entering the hydrogen chamber through the vent.

16 . The method of claim 11 , wherein
the hydrogen evolving electrode is part of a first electrochemical cell; and the first electrochemical cell comprises a first matrix containing an electrolyte; the first electrochemical cell comprises a hydrogen oxidizing electrode; the first matrix is at least partially situated between the hydrogen oxidizing electrode and the hydrogen evolving electrode; and the method comprises applying a voltage across the hydrogen evolving electrode and the hydrogen oxidizing electrode.

17 . The method of claim 16 , wherein
the reference electrode and the detection electrode are part of a second electrochemical cell; the second electrochemical cell includes a second matrix at least partially situated between the reference electrode and the detection electrode; and the second matrix contains phosphoric acid.

18 . The method of claim 11 , wherein the gas is in a fuel cell power plant reformer and the method comprises
determining an operating condition of the reformer based on the determined concentration of hydrogen in the gas; and adjusting operation of the reformer based on the operating condition.

19 . The method of claim 18 , wherein determining the operating condition and adjusting the operation are performed independent of determining a temperature in the reformer.

Assignees

• Doosan Fuel Cell America Inc

Inventors

• Preston Joshua
• Patterson Jr Timothy William

Classifications

• G01N27/407 Primary

  for investigating or analysing gases {(G01N27/411 takes precedence)} · CPC title

• Y02E60/50

  Fuel cells · CPC title

• G01N27/417 Primary

  using cells {, i.e. more than one cell} and probes with solid electrolytes · CPC title

• G01N33/0059

  Avoiding interference of a gas with the gas to be measured · CPC title

• G01N27/4074

  for detection of gases other than oxygen · CPC title