Air Control System and Method for Fuel Cell Stack System

Patent metadata

Field	Value
Publication number	US-2017338500-A1
Application number	US-201615158650-A
Country	US
Kind code	A1
Filing date	May 19, 2016
Priority date	May 19, 2016
Publication date	Nov 23, 2017
Grant date	—

Abstract

An airflow control method of an air control system for a fuel cell stack (FCS) includes opening a recirculation valve by a controller to recirculate air through a compressor to increase a temperature of the air prior to entering the FCS to offset a FCS temperature below a predetermined threshold in response to identification to a cold-start event. The recirculation valve may be arranged with the compressor to recirculate air therethrough. The FCS may be arranged with the compressor and recirculation valve to selectively receive air therefrom. A sensor may measure thermal conditions of the FCS. The controller may be programmed to receive signals from the sensor indicating thermal conditions of the FCS, and to operate the recirculation valve based on the signals to recirculate air through the compressor to increase a temperature of the air prior to entering the FCS.

First claim

What is claimed is:

1 . An airflow control method of an air control system for a fuel cell stack (FCS) comprising:
responsive to identification of a cold-start event, opening a recirculation valve by a controller to recirculate air through a compressor to increase a temperature of the air prior to entering the FCS to offset a FCS temperature below a predetermined threshold.

2 . The method of claim 1 further comprising increasing a speed of the compressor during the recirculation of the air to further increase a temperature thereof.

3 . The method of claim 1 further comprising increasing a speed of the compressor to a constant speed and varying an operational position of the recirculation valve such that a constant mass flow rate of air to the FCS is achieved.

4 . The method of claim 1 further comprising basing an operational position of the recirculation valve on data from an accessible table corresponding to valve positions relative to FCS temperature settings and increasing compressor speed based on the data to increase the FCS temperature above the predetermined threshold.

5 . The method of claim 1 further comprising increasing a speed of the compressor corresponding to an additional power draw from the FCS to support the increased speed and to further increase the temperature of the FCS.

6 . The method of claim 1 further comprising increasing a speed of the compressor based on detection of a mass flow rate of the air traveling to the FCS being below a predetermined flow threshold.

7 . The method of claim 1 further comprising identifying the cold-start event as an event in which temperature conditions of the FCS are at or near freezing.

8 . A fuel cell stack (FCS) air control system comprising:
a compressor; a recirculation valve arranged with the compressor to recirculate air therethrough; a FCS arranged with the compressor and recirculation valve to selectively receive air therefrom; a sensor to measure thermal conditions of the FCS; and a controller programmed to receive signals from the sensor indicating thermal conditions of the FCS, and to operate the recirculation valve based on the signals to recirculate air through the compressor to increase a temperature of the air prior to entering the FCS.

9 . The system of claim 8 , wherein the controller is further programmed to open the recirculation valve based on detection of a compressor surge event.

10 . The system of claim 8 , wherein the controller is further programmed to open the recirculation valve in response to receiving a signal from the sensor indicating a temperature of the FCS is below a predetermined threshold.

11 . The system of claim 10 , wherein the predetermined threshold is a temperature corresponding to the FCS having an ice condition therein.

12 . The system of claim 10 , wherein the predetermined threshold is a temperature corresponding to a cold-start event.

13 . The system of claim 8 , wherein the controller is further programmed to close the recirculation valve in response to receiving a signal from the sensor indicating a temperature of the FCS is above a predetermined threshold.

14 . The system of claim 8 , wherein the controller is further programmed to open the recirculation valve in response to receiving a temperature reading from the sensor indicating air within the FCS is below eighty degrees Celsius.

15 . A fuel cell vehicle comprising:
a fuel cell stack (FCS); an air control system including a compressor and a recirculation valve in fluid communication with the FCS; and a controller to direct operation of the air control system, and programmed to, in response to detection of a cold-start event, open the recirculation valve to recirculate air through the compressor to increase a temperature of the air for delivery to the FCS.

16 . The vehicle of claim 15 further comprising a sensor in communication with the controller to monitor thermal conditions of the FCS, wherein the sensor sends a cold-start event detection signal to the controller in response to thermal conditions of the FCS being below a predetermined threshold.

17 . The vehicle of claim 16 , wherein the predetermined threshold is a temperature in which an ice condition occurs within a fuel cell of the FCS.

18 . The vehicle of claim 15 , wherein the controller is further programmed to increase a speed of the compressor in response to detection of the cold-start event to increase a load draw from the FCS.

19 . The vehicle of claim 15 , wherein the controller is further programmed to close the recirculation valve in response to detecting a temperature of the FCS being above a predetermined threshold.

20 . The vehicle of claim 19 , wherein the predetermined threshold includes temperatures at or above eighty degrees Celsius.

Assignees

• Ford Global Tech Llc

Inventors

• Pryor Martin

Classifications

• H01M8/04111

  using a compressor turbine assembly · CPC title

• H01M8/04225

  during start-up · CPC title

• H01M8/04619

  of fuel cell stacks · CPC title

• H01M8/04067

  Heat exchange or temperature measuring elements, thermal insulation, e.g. heat pipes, heat pumps, fins · CPC title

• H01M2300/0082

  Organic polymers · CPC title