Fuel cell air system safe operating region

Patent metadata

Field	Value
Publication number	US-10714767-B2
Application number	US-201715835321-A
Country	US
Kind code	B2
Filing date	Dec 7, 2017
Priority date	Dec 7, 2017
Publication date	Jul 14, 2020
Grant date	Jul 14, 2020

Abstract

Methods, systems, and device for controlling air flow within a vehicle for electrical generation. The air control system includes at least one of an air compressor, a back pressure valve or a bypass valve that controls air flow. The air control system includes one or more components. The air control system includes an electronic control unit. The electronic control unit is configured to obtain an air flow target and an air pressure ratio target and determine that the one or more components will operate outside a safe operating region. The electronic control unit is configured to determine a mediated air flow target and a mediated air pressure ratio target that causes the one or more components to operate within the safe operating region. The electronic control unit is configured to adjust the at least one of the air compressor, the back pressure valve or the bypass valve.

First claim

What is claimed is:

1. An air control system for a vehicle, comprising:
an air compressor configured to control air flow of air;
at least one of a back pressure valve or a bypass valve configured to adjust the air flow;
an inter cooler configured to facilitate generation of electrical energy;
a fuel cell configured to generate the electrical energy; and
an electronic control unit configured to:
obtain an air flow target and an air pressure ratio target,
compare the air flow target and the air pressure ratio target to one or more respective threshold limits for each one of the air compressor and the inter cooler,
determine that the air flow target or the air pressure ratio target would cause the air compressor or the inter cooler to operate outside a safe operating region based on the comparison,
determine an acceptable air flow target and an acceptable air pressure ratio target that limits the air flow and an air pressure of the air to operate the air compressor, the inter cooler and the fuel cell within the safe operating region, and
adjust the air compressor, the back pressure valve or the bypass valve based on the acceptable air flow target and the acceptable air pressure ratio target.

2. The air control system of claim 1 , wherein the electronic control unit is configured to determine that an air temperature of air that exits or enters the air compressor, the inter cooler or the fuel cell is greater than a maximum threshold value for the air that exits or enters the air compressor, the inter cooler or the fuel cell, respectively.

3. The air control system of claim 1 , wherein to adjust the air compressor, the back pressure valve or the bypass valve the electronic control unit is configured to:
adjust the bypass valve to a partially opened position; and
adjust the back pressure valve to a closed position.

4. The air control system of claim 1 , wherein to adjust the air compressor the electronic control unit is configured to change a speed of a motor of the air compressor to increase or decrease the air flow.

5. The air control system of claim 4 , wherein outlet air out of the air compressor has a temperature that is less than a maximum allowable air temperature of air that enters and flows into the inter cooler.

6. An air control system for a vehicle, comprising:
an air compressor configured to control air flow of air;
an inter cooler configured to facilitate generation of electrical energy;
a fuel cell configured to generate the electrical energy;
one or more valves that control or adjust the air flow to the inter cooler or the fuel cell; and
an electronic control unit configured to:
obtain an air flow target and an air pressure ratio target,
compare the air flow target and the air pressure ratio target to one or more respective threshold limits for each one of the air compressor and the inter cooler,
determine that the air flow target or the air pressure ratio target would cause the air compressor or the inter cooler to operate outside a safe operating region based on the comparison,
determine an acceptable air flow target and an acceptable air pressure ratio target that causes the air compressor, the inter cooler and the fuel cell to operate within the safe operating region, and
adjust the one or more valves based on the acceptable air flow target and the acceptable air pressure ratio target.

7. The air control system of claim 6 , wherein to adjust the one or more valves the electronic control unit is configured to:
determine a position for the one or more valves including a back pressure valve or a bypass valve based on the acceptable air flow target and the acceptable air pressure ratio target; and
adjust the back pressure valve or the bypass valve based on the position.

8. The air control system of claim 6 , wherein to determine that the air flow target or the air pressure ratio target would cause the air compressor or the inter cooler to operate outside the safe operating region the electronic control unit is configured to determine that air that would enter and flow into the inter cooler would have an air temperature that is greater than a maximum threshold value.

9. The air control system of claim 6 , wherein to adjust the one or more valves the electronic control unit is configured to:
move a bypass valve to a partially open position; and
move a back pressure valve to a closed position.

10. The air control system of claim 6 , wherein the safe operating region of the inter cooler defines an air pressure ratio for air that enters the inter cooler that is greater than or equal to a minimum allowable pressure ratio and less than or equal to a maximum allowable pressure ratio.

11. The air control system of claim 10 , wherein the safe operating region provides for the air that enters the inter cooler to have a temperature that is less than a maximum allowable temperature.

12. An air control system, comprising:
an inter cooler that is configured to facilitate generation of electrical energy;
a fuel cell that is configured to generate the electrical energy;
an air compressor configured to control air flow of air that enters or exits the air compressor, the inter cooler or the fuel cell;
at least one of a back pressure valve or a bypass valve that is configured to adjust the air flow including an air flow rate or an air pressure ratio of the air; and
a processor configured to:
obtain an air flow rate target or an air pressure ratio target,
obtain one or more respective threshold limits for each of the air flow rate or the air pressure ratio of the air that enters or exits the air compressor and the inter cooler,
determine that the air flow rate target or the air pressure ratio target would cause the air compressor or the inter cooler to operate outside a safe operating region based on the comparison,
determine an acceptable air flow rate and an acceptable air pressure ratio that limits the air flow rate or the air pressure ratio of the air so that the air compressor, the inter cooler and the fuel cell operate within the safe operating region, and
adjust the air compressor, the back pressure valve or the bypass valve based on the acceptable air flow rate and the acceptable air pressure ratio.

13. The air control system of claim 12 , wherein to adjust the air compressor the processor is configured to change a speed of a motor of the air compressor to increase or decrease the air flow rate.

14. The air control system of claim 12 , wherein to adjust the back pressure valve or the bypass valve the processor is configured to:
adjust a position of the back pressure valve or the bypass valve to increase or decrease the air pressure ratio.

15. The air control system of claim 12 , wherein at least one of the air compressor, the back pressure valve or the bypass valve is further configured to control temperature of the air that enters or exits the air compressor, the inter cooler or the fuel cell.

16. The air control system of claim 12 , wherein to adjust the air compressor, the back pressure valve or the bypass valve the processor is configured to:
maintain the air pressure ratio and the air flow rate of the air that enters or exits the air compressor so that the air compressor does not operate within a surge region or a stall region, which are above a surge line and below a stall line, respectively.

Assignees

• Toyota Eng & Mfg North America

Inventors

• Farnsworth Jared

Classifications

• Y02E60/50

  Fuel cells · CPC title

• B60L1/003 Primary

  to auxiliary motors, e.g. for pumps, compressors · CPC title

• Y02T90/40

  Application of hydrogen technology to transportation, e.g. using fuel cells · CPC title

• B60L2240/36

  Temperature of vehicle components or parts · CPC title

• B60L1/02

  to electric heating circuits · CPC title