Coolant systems for electric and hybrid-electric vehicles

• US 8,393,551 B2
• Filed: 07/18/2008
• Issued: 03/12/2013
• 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 LLC (General Motors Company)
• Inventors: Nemesh, Mark D., Martinchick, Matthew J., Pleune, Jeffrey M., Ibri, Wissam
• Primary Examiner(s): McAllister, Steven B
• Assistant Examiner(s): DECKER, PHILLIP
• Application Number:
  US12/175,477
• Publication Number:
  US 20100012741A1
• Time in Patent Office: 1,698 Days
• Field of Search: 237/12.3 B, 237/2.A, 701/102
• US Class Current: 237/12.3B
• 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 fuel cell stack and a battery pack, the method comprising the steps of:

(a) detecting a fuel cell stack warm up condition, the warm up condition being when the fuel cell stack is below a predetermined temperature range and is warming up;

(b) if the fuel cell stack warm up condition is detected, activating a pump and a cabin coolant heater upstream from a heater core, which 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;

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

(d) detecting a mountain grade descent condition, the mountain grade descent condition including at least that the vehicle is traveling downhill;

(e) detecting a battery limit condition, the battery limit condition including the battery pack reaching an upper limit;

(f) 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; and

(g) 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.

2. The method of claim 1 wherein step (b) is further defined by:

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

3. 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, the warm up condition being when the fuel cell stack is below a predetermined temperature range and is warming up;

(b) if the fuel cell stack warm up condition is detected, activating a pump and a cabin coolant heater upstream from a heater core, which 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;

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

(d) detecting a mountain grade descent condition, the mountain grade descent condition including at least that the vehicle is traveling downhill;

(e) detecting a battery limit condition, the battery limit condition including the battery pack reaching an upper limit; and

(f) 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.

4. The method of claim 3 wherein step (f) 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.