Cathode inlet humidity sensing with oxygen sensor

Patent metadata

Field	Value
Publication number	US-2021242478-A1
Application number	US-202016777209-A
Country	US
Kind code	A1
Filing date	Jan 30, 2020
Priority date	Jan 30, 2020
Publication date	Aug 5, 2021
Grant date	—

Abstract

A fuel cell system includes a stack of proton exchange membrane (PEM) fuel cells defining a body, the body including a coolant inlet and coolant outlet, a cathode inlet and cathode outlet corresponding to a cathode, an anode inlet and an anode outlet corresponding to an anode. The fuel cell system also includes a cathode humidifier fluidly connected to the cathode inlet to provide a humidified inlet stream to the cathode inlet, an oxygen sensor positioned upstream of the cathode inlet and downstream of the cathode humidifier, and configured to measure oxygen content of the humidified inlet stream, and a controller connected to the cathode humidifier and the oxygen sensor and configured to operate the cathode humidifier based on the oxygen content of the humidified inlet stream.

First claim

What is claimed is:

1 . A fuel cell system comprising:
a stack of proton exchange membrane (PEM) fuel cells defining a body, the body including a coolant inlet and coolant outlet, a cathode inlet and cathode outlet corresponding to a cathode, an anode inlet and an anode outlet corresponding to an anode; a cathode humidifier fluidly connected to the cathode inlet to provide a humidified inlet stream to the cathode inlet; an oxygen sensor positioned upstream of the cathode inlet and downstream of the cathode humidifier, and configured to measure oxygen content of the humidified inlet stream; and a controller connected to the cathode humidifier and the oxygen sensor and configured to operate the cathode humidifier based on the oxygen content of the humidified inlet stream.

2 . The fuel cell system of claim 1 , further comprising an air compressor fluidly connected to the cathode humidifier to provide an inlet air stream to die cathode humidifier such that water vapor is added to the inlet air stream to form the humidified inlet stream exiting the cathode humidifier.

3 . The fuel cell system of claim 2 , wherein die cathode humidifier is fluidly connected to die cathode inlet via a valve upstream of the oxygen sensor to control a flow of the humidified inlet stream to the cathode.

4 . The fuel cell system of claim 1 , further comprising an air compressor fluidly connected to the cathode inlet and providing an inlet air stream upstream of die oxygen sensor and cathode humidifier such that a water vapor stream is added to the inlet air stream from the cathode humidifier to form the humidified inlet stream, and wherein the cathode humidifier is fluidly connected to the inlet air stream by a valve such that the water vapor stream is controlled.

5 . The fuel cell system of claim 1 , further comprising a temperature sensor and a pressure sensor, both of the temperature and pressure sensors located downstream of the cathode humidifier and upstream of the oxygen sensor.

6 . The fuel cell system of claim 1 , wherein the oxygen sensor is a universal exhaust gas oxygen (UEGO) sensor.

7 . A vehicle comprising:
a stack of proton exchange membrane (PEM) fuel cells arranged to provide power to the vehicle and defining a body, the body including a coolant inlet and coolant outlet, a cathode inlet and cathode outlet corresponding to a cathode, an anode inlet and an anode outlet corresponding to an anode; a cathode humidifier fluidly connected to the cathode inlet to provide a humidified inlet stream to the cathode via the cathode inlet; an oxygen sensor downstream of the cathode humidifier and upstream of the cathode inlet to measure an oxygen content of the humidified inlet stream; and a controller connected to the cathode humidifier and the oxygen sensor and configured to
determine a relative humidity of the humidified inlet stream based on the oxygen content provided from the oxygen sensor, and,
upon the relative humidity being less than a predefined threshold humidity, operate the cathode humidifier to increase the relative humidity.

8 . The vehicle of claim 7 , further comprising an air compressor fluidly connected to the cathode humidifier such that water vapor is added to an inlet air stream to form the humidified inlet stream, and wherein the cathode humidifier is fluidly connected to the cathode inlet via a valve upstream of the oxygen sensor such that the controller operates the valve to control a flow of the humidified inlet stream to the cathode.

9 . The vehicle of claim 7 , further comprising an air compressor fluidly connected to the cathode inlet and providing an inlet air stream upstream of the oxygen sensor and cathodic humidifier such that a water vapor stream is added to the inlet air stream from the cathode humidifier to form the humidified inlet stream.

10 . The vehicle of claim 9 , wherein the cathode humidifier is fluidly connected to the inlet air stream by a valve such that the controller operates the valve to control the water vapor stream.

11 . The vehicle of claim 7 , further comprising a temperature sensor and a pressure sensor, both sensors located downstream of the cathode humidifier and upstream of the oxygen sensor, the temperature and pressure sensors providing temperature and pressure data, respectively, to the controller for determining relative humidity.

12 . The vehicle of claim 7 , wherein the controller is further configured to, upon the relative humidity being more than or equal to the predefined threshold humidity and less than a maximum humidity, operate the cathode humidifier to maintain the relative humidity.

13 . The vehicle of claim 12 , wherein the controller is further configured to, upon the relative humidity being more than the maximum humidity, operate the cathode humidifier to reduce the relative humidity to below the maximum humidity.

14 . The vehicle of claim 7 , wherein the oxygen sensor is a universal exhaust gas oxygen (UEGO) sensor.

15 . A fuel cell system comprising:
a stack of proton exchange membrane (PEM) fuel cells defining a body, the body including a coolant inlet and coolant outlet, a cathode inlet and cathodic outlet corresponding to a cathode, an anode inlet and an anode outlet corresponding to an anode; a cathode humidifier fluidly connected to the cathode inlet to provide a humidified inlet stream to the cathode inlet; an oxygen sensor positioned upstream of the cathode inlet and downstream of the cathode humidifier, and configured to measure oxygen content of the humidified inlet stream; and a controller connected to the cathode humidifier and the oxygen sensor and configured to operate the cathode humidifier based on the oxygen content of the humidified inlet stream such that
upon a relative humidity being less than a predefined threshold humidity, the cathode humidifier increases the relative humidity, and
upon the relative humidity being more than or equal to the predefined threshold humidity and less than a maximum humidity, die cathode humidifier maintains the relative humidity.

16 . The fuel cell system of claim 15 , wherein die oxygen sensor is a universal exhaust gas oxygen (UEGO) sensor.

17 . The fuel cell system of claim 15 , wherein the controller is further configured to, upon the relative humidity being more than the maximum humidity, operate the cathode humidifier to reduce the relative humidity to below the maximum humidity.

18 . The fuel cell system of claim 15 , further comprising an air compressor fluidly connected to the cathode humidifier to provide an inlet air stream to the cathode humidifier such that water vapor is added to the inlet air stream to form the humidified inlet stream exiting the cathode humidifier, and the cathode humidifier is fluidly connected to the cathode inlet via a valve upstream of the oxygen sensor to control a flow of the humidified inlet stream to the cathode.

19 . The fuel cell system of claim 15 , further comprising an air compressor fluidly connected to the cathode inlet and providing an inlet air stream upstream of the oxygen sensor and cathode humidifier, wherein the cathode humidifier is fluidly connected to the inlet air stream by a valve that controls a water vapor stream added to the inlet air stream to form the humidified inlet stream.

20 . The fuel cell system of claim 15 , further comprising a temperature sensor and a pressure sensor, both of the temperature and pressure sensors located downstream of the cathode humidifier and upstream of the oxygen sensor.

Assignees

• Ford Global Tech Llc

Inventors

• Son Seha
• Soltis Richard E
• Hepburn Jeffrey Scott
• Sanderson William Frederick

Classifications

• H01M2250/20

  Fuel cells in motive systems, e.g. vehicle, ship, plane · CPC title

• H01M2008/1095

  Fuel cells with polymeric electrolytes · CPC title

• H01M8/04835

  of fuel cell reactants · CPC title

• H01M8/04507 Primary

  of cathode reactants at the inlet or inside the fuel cell · CPC title

• H01M8/04455

  of cathode reactants at the inlet or inside the fuel cell · CPC title