NOISE-COMFORT FUNCTION FOR COOLING SYSTEMS WITH PROPORTIONAL VARIABLE SPEED FANS

• US 20080217080A1
• Filed: 03/09/2007
• Published: 09/11/2008
• Est. Priority Date: 03/09/2007
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations LLC (General Motors Company)
• Inventors: Maier, Oliver
• Granted Patent: US 7,793,746 B2
• Time in Patent Office: Days
• US Class Current: 180/65.3
• CPC Class Codes: B60K 11/02 with liquid cooling
• CPC Class Codes: B60K 2001/005 the electric storage means
• CPC Class Codes: H01M 8/04014 Heat exchange using gaseous fluids; Heat exchange by combustion of reactants
• CPC Class Codes: Y02E 60/50 Fuel cells
• CPC Class Codes: Y10S 903/908 Fuel cell

Abstract

A method for operating a cooling system for a fuel cell stack in a vehicle is provided. The method includes the steps of: determining a fan request for a variable speed fan disposed in the cooling system; employing a noise-comfort function to select a fan comfort request; and adjusting a speed of the variable speed fan in response to the fan request; wherein a noise emission by the variable speed fan is militated against. A cooling system for a fuel cell stack in a vehicle that employs the noise-comfort function is also provided.

Claims

1. A cooling system for a fuel cell stack in a vehicle, the cooling system comprising:

a coolant source in fluid communication with the fuel cell stack,

a variable speed fan adapted to reduce a temperature of a coolant; and

a controller having a noise comfort function, the controller adapted to receive at least one signal and provide a fan command to the variable speed fan, wherein a speed of the variable speed fan is controlled based on the fan command.

2. The cooling system of claim 1, further comprising:

at least one power sensor adapted to measure a power output of the fuel cell stack; and

at least one velocity sensor adapted to measure a speed of the vehicle;

wherein the controller is in communication with the at least one power sensor and the at least one velocity sensor.

3. The cooling system of claim 2, wherein the at least one signal includes a power output signal from the at least one power sensor and a vehicle speed signal from the at least one velocity sensor.

4. The cooling system of claim 1, further comprising:

a bypass conduit in communication with the fuel cell stack; and

a coolant valve adapted to provide the coolant to one of the coolant source and the bypass conduit as desired.

5. The cooling system of claim 1, wherein the variable speed fan is a high performance fan.

6. The cooling system of claim 1, wherein the at least one signal includes a fan request signal from at least one of the fuel cell stack, a power electronics controller, and a vehicle climate controller.

7. A method of operating a cooling system for a fuel cell stack in a vehicle comprising the steps of:

determining a fan request for a variable speed fan disposed in the cooling system;

employing a noise-comfort function to select a fan comfort request; and

adjusting a speed of the variable speed fan in response to the fan request and the fan comfort request, wherein a noise emission by the variable speed fan is militated against.

8. The method of claim 7, wherein the fan comfort request has a value lower than a value of the one or more fan requests.

9. The method of claim 7, wherein the fan command is selected to optimize a cooling of the fuel cell stack and the noise emission by the variable speed fan.

10. The method of claim 7, wherein the noise-comfort function correlates a power of the fuel cell stack, a speed of the vehicle, and a fan noise emission to select the fan comfort request.

11. The method of claim 7, wherein the noise-comfort function includes a look-up table having the fan comfort request as a function of one or more variables.

12. The method of claim 7, wherein the noise-comfort function includes a linear equation having the fan comfort request as a function of at least one variable.

13. The method of claim 7, wherein the employing of the noise-comfort function includes the step of measuring at least one variable including a stack power and a vehicle speed.

14. The method of claim 13, wherein the power of the fuel cell stack is determined by measuring by a current of the fuel cell stack and a voltage of the fuel cell stack.

15. The method of claim 14, wherein the step of measuring of the current and the voltage includes filtering a current measurement and a voltage measurement, wherein a signal noise is minimized.

16. The method of claim 13, wherein the employing of the noise-comfort function includes the steps of:

correlating the power of the fuel cell stack to a first fan comfort request, and

correlating the vehicle speed to a second fan comfort request, wherein the fan comfort request is the lesser of a value of the first fan comfort request and a value of the second fan comfort request.

17. The method of claim 7, wherein the fan comfort request is a minimum value when a vehicle speed is within a minimum range and a stack power is within a minimum range.

18. The method of claim 7, wherein the fan comfort request is a maximum value when a vehicle speed is within a minimum range and a stack power is within a maximum range.

19. A method of operating a cooling system for a fuel cell stack in a vehicle comprising the steps of:

determining a plurality of desired fan requests for a variable speed fan disposed in the cooling system;

selecting a maximum fan request from the plurality of desired fan requests;

employing a noise-comfort function to select a fan comfort request;

selecting a fan command from the maximum fan request and the fan comfort request; and

adjusting a speed of the variable speed fan in response to the fan command, wherein a noise emission by the variable speed fan is militated against.

20. The method of claim 19, wherein the step of determining the plurality of fan requests includes:

determining a fan request for a fuel cell stack;

determining a fan request for a power electronics controller; and

determining a fan request for a vehicle climate controller.