HUMID STREAM ORIFICE VIA GEOMETRY AND MATERIAL THAT IS ROBUST TO BECOMING BLOCKED

• US 20130295479A1
• Filed: 05/06/2013
• Published: 11/07/2013
• Est. Priority Date: 05/07/2012
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations LLC (General Motors Company)
• Inventors: Barter, Stuart D., Owejan, Jon P., Towner, Christopher J.
• Granted Patent: US 9,190,675 B2
• Time in Patent Office: Days
• US Class Current: 429/429
• CPC Class Codes: F16K 31/0672 the valve member being a diaphragm
• CPC Class Codes: H01M 2250/20 Fuel cells in motive systems, e.g. vehicle, ship, plane
• CPC Class Codes: H01M 8/04089 of gaseous reactants
• CPC Class Codes: H01M 8/04225 during start-up
• CPC Class Codes: H01M 8/04253 Means for solving freezing problems
• CPC Class Codes: H01M 8/04268 Heating of fuel cells during the start-up of the fuel cells
• CPC Class Codes: H01M 8/04302 applied during start-up
• CPC Class Codes: Y02E 60/50 Fuel cells
• CPC Class Codes: Y02T 90/40 Application of hydrogen technology to transportation, e.g. using fuel cells

Abstract

A component for reducing the likelihood of ice-related blockage in a fuel cell and methods for starting a fuel cell system. In one embodiment, the component is a separate insert configured with a sharp leading edge such that water droplets present in a reactant fluid that pass through an orifice in the component are conveyed away from an unstable formation at the edge to a more stable formation in an adjacent part of the component. In one form, the component is sized to fit within a valve inlet that in turn is placed in a humid reactant flowpath. In this way, when the fuel cell is operated in cold conditions—such as those associated with temperatures at or below the freezing point of water—the water droplets do not freeze in the area around the orifice such that ice-related blockage of the flowpath does not occur.

Claims

1. An ice-resistant valve for use in a fuel cell system, said valve comprising.

a fluid inlet configured to receive a fuel cell reactant;

a fluid outlet disposed fluidly downstream of said fluid inlet; and

a body defining a fluid reactant passageway therethrough that is cooperative with said fluid inlet and said fluid outlet, at least one of said fluid reactant passageway, said fluid inlet and said fluid outlet defining an orifice therein that is configured with at least one sharp edge such that at least a portion of moisture contained within said fuel cell reactant that deposits on said edge is conveyed from said orifice in environmental conditions where said deposited moisture may be prone to freezing in order to have such freezing take place away from said orifice to prevent ice blockage thereto.

2. The valve of claim 1, wherein said at least one sharp edge defines a leading edge of said orifice relative to a travel path defined by said fuel cell reactant.

3. The valve of claim 2, wherein said orifice defined in said fluid inlet further comprises a gutter formed around a periphery of said at least one sharp edge such that said deposits on said edge that are conveyed away from said orifice proceed toward said gutter.

4. The valve of claim 3, wherein said orifice defined in said fluid inlet is formed as part of a separate insert disposed within at least one of said fluid reactant passageway, said fluid inlet and said fluid outlet.

5. The valve of claim 4, wherein said separate insert is made from an aluminum-based material.

6. The valve of claim 4, wherein said valve is oriented in said fuel cell system such that during normal operation thereof, the portion of said fluid reactant passageway that contains said orifice is oriented in a substantially horizontal dimension such that moisture collecting on said at least one sharp edge drains away from said orifice along said gutter to a collection location within said insert.

7. The valve of claim 1, wherein said orifice defined in said fluid inlet is formed as part of a separate insert disposed within at least one of said fluid reactant passageway, said fluid inlet and said fluid outlet.

8. The valve of claim 1, wherein said valve avoids the use of a heating device or vibratory movement to facilitate such prevention of ice blockage.

9. The valve of claim 1, wherein said orifice defined in said fluid inlet is formed as part of a separate insert disposed within said fluid reactant passageway.

10. The valve of claim 1, wherein said orifice defines a substantially axisymmetric passage formed in said fluid inlet such that at least a portion of said deposited moisture that forms on said at least one edge is conveyed first toward a gutter formed outwardly adjacent said at least one edge and then to a corner formed outwardly adjacent said gutter.

11. A method of inhibiting freeze-related blockage of a reactant flowpath in an automotive fuel cell system, said method comprising:

configuring a valve to be fluidly cooperative with said reactant flowpath, said valve defining a fluid reactant passageway therethrough, at least a portion of said valve defining an orifice therein that is configured with at least one sharp edge;

passing at least one of a hydrogen-bearing reactant and an oxygen-bearing reactant through said valve in environmental conditions where moisture present in said at least one reactant may be prone to freezing such that at least a portion of said moisture forms unstable water droplets on said at least one sharp edge; and

conveying said formed water droplets away from said orifice in order to have such freezing take place in such a location as to not impede passage the flow of said at least one reactant through said orifice.

12. The method of claim 11, further comprising configuring said portion of said valve that defines said orifice therein to further comprise a gutter formed around a periphery of said at least one sharp edge such that at least a portion of said deposits on said edge that are conveyed away from said orifice proceed toward said gutter.

13. The method of claim 12, further comprising configuring said portion of said valve that defines said orifice therein to comprise a corner formed around a periphery of said gutter such that at least a portion of said deposits that are conveyed away from said gutter orifice proceed toward said corner.

14. The method of claim 13, wherein said orifice is formed as part of a separate insert disposed within said valve.

15. The method of claim 11, wherein said orifice is formed as part of a separate insert disposed within said valve.

16. A method of promoting cold catalytic heating during a fuel cell stack cold start in an environmental condition where moisture present in a reactant flowstream may be prone to freezing, said method comprising:

passing at least one of a hydrogen-bearing reactant and an oxygen-bearing reactant through a valve such that at least a portion of said moisture contained in said at least one reactant forms unstable water droplets on at least one sharp edge of an orifice that defines a fluid reactant passageway in said valve;

conveying said formed water droplets away from said orifice in order to have such freezing take place in such a location as to not impede passage the flow of said at least one reactant through said orifice;

combining said hydrogen-bearing reactant and said oxygen-bearing reactant in an electrochemical reaction such that a catalytic generation of heat takes place; and

using said catalytic generation of heat to increase the temperature of at least a portion of said stack.

17. The method of claim 16, wherein a region surrounding said orifice comprises a gutter formed around a periphery of said at least one sharp edge and a corner formed around a periphery of said gutter such that at least a portion of said conveyed water droplets proceed toward said corner past said gutter.

18. The method of claim 17, wherein said orifice is formed as part of a separate insert disposed within said valve, said separate insert configured to define a gap between an outer surface thereof and an adjacent inner surface of said valve such that at least a portion of said conveyed water droplets pass into said gap.

19. The method of claim 16, wherein said orifice and said at least one edge define a substantially axisymmetric profile with a diameter of about 2 millimeters.

20. The method of claim 19, wherein said orifice and said at least one edge define a substantially volcanic-shaped profile.