Coolant Systems For Electric And Hybrid-Electric Vehicles

• US 20100012741A1
• Filed: 07/18/2008
• Published: 01/21/2010
• Est. Priority Date: 07/18/2008
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations Incorporated (Motors Liquidation Co. GUC Trust)
• Inventors: Martinchick, Matthew J., Ibri, Wissam, Nemesh, Mark D., Pleune, Jeffrey M.
• Granted Patent: US 8,393,551 B2
• Time in Patent Office: Days
• US Class Current: 237/2.A
• CPC Class Codes: B60H 1/00392 for electric vehicles having only electric drive means
• CPC Class Codes: B60H 1/00764 the input being a vehicle driving condition, e.g. speed B60H1/00828, B60H1/00864 take precedence
• CPC Class Codes: B60H 1/02 the heat being derived from the propulsion plant B60H1/00492 takes precedence
• CPC Class Codes: B60K 2001/005 the electric storage means
• CPC Class Codes: B60K 6/48 Parallel type
• CPC Class Codes: B60W 2510/244 Charge state
• CPC Class Codes: B60W 2552/15 Road slope, i.e. the inclination of a road segment in the longitudinal direction
• CPC Class Codes: H01M 10/443 in response to temperature
• CPC Class Codes: H01M 10/486 for measuring temperature
• CPC Class Codes: H01M 10/613 Cooling or keeping cold
• CPC Class Codes: H01M 10/625 Vehicles
• CPC Class Codes: H01M 2250/20 Fuel cells in motive systems, e.g. vehicle, ship, plane
• CPC Class Codes: H01M 8/0432 Temperature; Ambient temperature
• CPC Class Codes: H01M 8/04701 Temperature
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02E 60/50 Fuel cells
• CPC Class Codes: Y02T 10/62 Hybrid vehicles
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 90/40 Application of hydrogen technology to transportation, e.g. using fuel cells

Abstract

A coolant system and method of operating the coolant system for a vehicle having a battery pack is disclosed. A method may include detecting a mountain grade descent condition; detecting a battery limit condition; and, if the mountain grade descent condition and the battery limit condition are detected, activating a coolant heater and a coolant pump to thereby accomplish an electric load shed. A method may include detecting a fuel cell stack warm up condition; and, if the fuel cell stack warm up condition is detected, activating a fuel cell coolant heater, a cabin coolant heater and a pump, and directing a coolant flowing through the cabin coolant heater through the fuel cell coolant heater and through a fuel cell stack to thereby warm the fuel cell stack.

Claims

1. A method of operating a coolant system for a vehicle having a battery pack, the method comprising the steps of:

(a) detecting a mountain grade descent condition;

(b) detecting a battery limit condition; and

(c) if the mountain grade descent condition and the battery limit condition are detected, activating a coolant heater and a coolant pump to thereby accomplish an electric load shed.

2. The method of claim 1 wherein step (b) is further defined by the battery limit condition being a predetermined battery thermal limit.

3. The method of claim 1 wherein step (b) is further defined by the battery limit condition being a battery state-of-charge that is approximately 100%.

4. The method of claim 1 wherein step (c) is further defined by:

if the mountain grade descent condition and the battery limit condition are detected, routing a coolant flowing through the coolant heater through a radiator to thereby dissipate heat from the coolant.

5. The method of claim 1 wherein step (c) is further defined by the coolant heater being a cabin coolant heater and the coolant pump being a cabin coolant pump, the cabin coolant heater and the cabin coolant pump being a part of a cabin heating branch that directs a coolant through a heater core in a HVAC module.

6. The method of claim 5 including the step of:

(d) if the mountain grade descent condition and the battery limit condition are detected, activating a fuel cell coolant heater and a fuel cell coolant pump to thereby increase the electric load shed.

7. The method of claim 1 wherein step (c) is further defined by the coolant heater being a fuel cell coolant heater and the coolant pump being a fuel cell coolant pump, the fuel cell coolant pump and the fuel cell coolant heater being part of a coolant circuit that directs a coolant through a fuel cell stack.

8. The method of claim 1 including the steps of:

(d) detecting a fuel cell stack warm up condition; and

(e) if the fuel cell stack warm up condition is detected, activating a fuel cell coolant heater, a cabin coolant heater and a pump, and directing a coolant flowing through the cabin coolant heater through the fuel cell coolant heater and through a fuel cell stack to thereby warm the fuel cell stack.

9. The method of claim 8 including the step of:

(f) if the fuel cell stack warm up condition is detected, adjusting a temperature blend door to redirect an air flow in a HVAC module around a heater core.

10. The method of claim 8 including the step of:

(f) if the fuel cell stack warm up condition is detected, adjusting a blower to minimize an air flow in a HVAC module.

11. A method of operating a coolant system for a vehicle having a fuel cell stack and a battery pack, the method comprising the steps of:

(a) detecting a fuel cell stack warm up condition; and

(b) if the fuel cell stack warm up condition is detected, activating a pump and a cabin coolant heater upstream from a heater core that is located in a HVAC module, and directing a coolant flowing through the cabin coolant heater, through the heater core and through a fuel cell stack to thereby warm the fuel cell stack.

12. The method of claim 11 including the step of:

(c) if the fuel cell stack warm up condition is detected, adjusting a blower to minimize an air flow in the HVAC module.

13. The method of claim 11 including the steps of:

(c) detecting a mountain grade descent condition;

(d) detecting a battery limit condition; and

(e) if the mountain grade descent condition and the battery limit condition are detected, activating the cabin coolant heater, which is a part of a cabin heating branch that directs a coolant through the heater core in the HVAC module, to thereby accomplish an electric load shed.

14. The method of claim 13 including the steps of:

(f) if the mountain grade descent condition and the battery limit condition are detected, activating a fuel cell coolant heater to thereby increase the electric load shed.

15. The method of claim 11 including the steps of:

(c) detecting a mountain grade descent condition;

(d) detecting a battery limit condition; and

(e) if the mountain grade descent condition and the battery limit condition are detected, activating a fuel cell coolant heater to thereby accomplish an electric load shed.

16. The method of claim 15 wherein step (e) is further defined by:

if the mountain grade descent condition and the battery limit condition are detected, routing the coolant flowing through the fuel cell coolant heater through a radiator to thereby dissipate heat from the coolant.

17. The method of claim 11 wherein step (b) is further defined by:

if the fuel cell stack warm up condition is detected, activating a fuel cell coolant heater and directing the coolant flow from the fuel cell coolant heater through the fuel cell stack.

18. A coolant system for a vehicle having a fuel cell stack comprising:

a cabin heating branch including a shut off valve configured to prevent a flow of a coolant through the cabin heating branch, a cabin coolant pump configured to selectively pump the coolant through the cabin heating branch, a cabin coolant heater having a first heating capacity and configured to selectively warm the coolant flowing through the cabin heating branch, and a heater core configured to mount in a HVAC module;

a radiator branch including a radiator configured to dissipate heat from the coolant flowing from the fuel cell through the radiator and a valve configured to control the coolant flow through the radiator;

a fuel cell pump configured to receive the coolant from the cabin heating branch and the radiator branch and pump the coolant through the fuel cell stack; and

a fuel cell coolant heater having a second heating capacity that is equal to the first heating capacity.

19. The system of claim 18 including a radiator bypass branch configured to selectively direct the coolant flow to bypass the radiator, the radiator bypass branch including a bypass shut-off valve configured to selectively block the flow of the coolant through the radiator bypass branch.