Diaphragm pump for a fuel cell system

• US 9,515,336 B2
• Filed: 08/13/2015
• Issued: 12/06/2016
• Est. Priority Date: 08/11/2005
• Status: Active Grant

• Current Assignee: Intelligent Energy Limited (Lb-shell Plc)
• Original Assignee: Intelligent Energy Limited (Lb-shell Plc)
• Inventors: Braithwaite, Daniel, Fabian, Tibor, Fisher, Tobin J., Glassmann, Jonathan Louis, Peterson, Andrew Gust, RODRIGUEZ, ADAM
• Primary Examiner(s): Alejandro, Raymond
• Application Number:
  US14/825,742
• Publication Number:
  US 20150349357A1
• Time in Patent Office: 481 Days
• US Class Current: 1/1
• CPC Class Codes: F04B 43/046 with piezoelectric drive
• CPC Class Codes: F04B 53/10 Valves; Arrangement of valves
• CPC Class Codes: F04B 53/14 Pistons, piston-rods or piston-rod connections
• CPC Class Codes: H01M 2008/1095 Fuel cells with polymeric electrolytes
• CPC Class Codes: H01M 2250/30 Fuel cells in portable systems, e.g. mobile phone, laptop
• CPC Class Codes: H01M 8/04089 of gaseous reactants
• CPC Class Codes: H01M 8/04201 Reactant storage and supply, e.g. means for feeding, pipes
• CPC Class Codes: H01M 8/04208 Cartridges, cryogenic media or cryogenic reservoirs
• CPC Class Codes: H01M 8/04216 characterised by the choice for a specific material, e.g. carbon, hydride, absorbent
• CPC Class Codes: H01M 8/0606 with means for production of gaseous reactants
• CPC Class Codes: H01M 8/065 by dissolution of metals or alloys; by dehydriding metallic substances
• CPC Class Codes: Y02B 90/10 Applications of fuel cells in buildings
• CPC Class Codes: Y02E 60/50 Fuel cells

Abstract

A method of supplying fuel to a fuel cell system wherein a flexible diaphragm controls ingress and egress of liquid reactant. The method utilizes a pump assembly including a first subassembly and a second subassembly. The first subassembly includes a fluid conduit; an inlet fluidly coupled to the liquid reactant dispenser and the fluid conduit; an outlet fluidly coupled to a reaction chamber and the fluid conduit; and a diaphragm, defining a portion of the fluid conduit, that flexes to pump the liquid reactant from the inlet to the outlet. The diaphragm preferably includes an actuation point coupled to the diaphragm, wherein the liquid reactant is substantially contained within the first subassembly during pumping. The second subassembly is couplable to the first subassembly, and is fluidly isolated from the liquid reactant wherein operation of the actuator causes diaphragm flexion.

Claims

1. A method of supplying fuel to operate a fuel cell system comprising:

a fuel cartridge including a liquid reactant dispenser containing a liquid reactant and a reaction chamber distinct from the liquid reactant dispenser, a pump assembly including;

a first subassembly including;

a fluid conduit, an inlet fluidly coupled to the liquid reactant dispenser and the fluid conduit, an outlet fluidly coupled to the reaction chamber and the fluid conduit, a diaphragm that defines a portion of the fluid conduit and that flexes to pump the liquid reactant from the inlet to the outlet, and an actuation point coupled to the diaphragm;

wherein the liquid reactant is substantially contained within the first subassembly during pumping; and

,

a second subassembly, couplable to the first subassembly and fluidly isolated from the liquid reactant, the second subassembly including an actuator that couples to the actuation point, wherein operation of the actuator causes diaphragm flexion;

flexing the diaphragm between a flexed and unflexed state; and

,

wherein the flexed state creates a positive pressure within the fluid conduit so as to facilitate the egress of the liquid reactant from the outlet, and the unflexed state creates a negative pressure within the fluid conduit the facilitate ingress of liquid reactant from the inlet.

2. The method of claim 1, the fluid conduit comprising substantially rigid prismatic pumping chamber, wherein the diaphragm forms a chamber wall proximal to an exterior wall of the first subassembly, the inlet being located on a wall adjacent to the diaphragm, and the outlet being located on a wall opposing the inlet.

3. The method of claim 2, wherein the inlet and outlet include a one-way inlet valve and outlet valve, respectively.

4. The method of claim 1, wherein the spring force of the diaphragm transitions the diaphragm from the flexed to the unflexed state.

5. The method of claim 1, the fluid conduit comprising a substantially flexible tube, wherein the diaphragm is a longitudinal portion of the tube and first and second ends of the tube form the inlet and outlet, respectively.

6. The method of claim 5, the first subassembly further including an auxiliary component that couples the actuation point to the diaphragm, the auxiliary component being a rotor, wherein the actuation point is substantially in the center of the rotor end face and the diaphragm is slidably disposed about a portion of the rotor circumference, such that the diaphragm substantially contacts the portion of the rotor circumference for a majority of the operating time,

said method comprising rotating the rotor.

7. The method of claim 2, wherein the auxiliary component comprises a concave groove disposed on the diaphragm most interior to the first subassembly, such that the auxiliary component is concave toward the center of the exterior of the first subassembly and the diaphragm is disposed between the auxiliary component and the exterior of the first subassembly,

said method comprising compressing a portion of the diaphragm to occlude the diaphragm against the concave groove.

8. The method of claim 1, the first subassembly further including an auxiliary component that couples the actuation point to the diaphragm, the auxiliary component being a reciprocating rod disposed between the exterior of the first assembly and the diaphragm, with a diaphragm end and a distal end, wherein the distal end is the actuation point, wherein the rod transfers a force from the actuator to the diaphragm.

9. The method of claim 1, wherein the actuator comprises a shape memory alloy.

10. The method of claim 1, wherein actuator comprises a rotatable cam, said cam having an axis of rotation offset from center.

11. The method of claim 1, wherein actuator comprises a piezoelectric driver.

12. The method of claim 1, wherein the diaphragm comprises silicone rubber, polyethylene, PVC, PEEK, PTFE, aluminum, copper, cobalt, nitinol, magnetite, or a combination thereof.

13. The method of claim 1, wherein the second subassembly further includes a translating member coupled to the actuator, wherein the actuator reciprocates the translating member between two states:

retracted mode wherein the translating member does not transfer substantial force from the actuator to the diaphragm, wherein the diaphragm is in the unflexed state; and

an extended mode wherein the translating member transfers substantial force from the actuator to the actuation point, wherein the diaphragm is in the flexed state;

said method comprising moving the translating member between the retracted mode and the extended mode.

14. The method of claim 13, wherein the translating member contacts the actuation point in retracted mode.

15. The method of claim 13, wherein the translating member is moved between the retracted mode and the extended mode by the application of a changing magnetic field between the second assembly and the diaphragm, said changing magnetic field resulting in a linear translation against the diaphragm, flexing the diaphragm.

16. The method of claim 14, wherein the translating member is a pump plunger.

17. The method of claim 13, wherein the actuator is a mechanical actuator.

18. The method of claim 17, wherein the actuator is a screw actuator, wherein the translating member is the screw.

19. The method of claim 1, wherein the pump assembly further includes a coupling mechanism that removably couples the first subassembly to the second subassembly.

20. The method of claim 19, wherein the coupling mechanism is a tongue and groove couple, wherein the first subassembly includes a tongue and the second subassembly includes a groove.