Claims
- 1. An aircraft power system for generating power form a reactant, comprising:
a fuel cell configured to generate power using a gaseous form of the reactant, the fuel cell being configured to operate at a power-generation rate requiring the gaseous reactant to be supplied at an operating-rate of flux; and a tank configured for containing a liquid form of the reactant, wherein the tank includes a heat source for increasing a boiling-rate of the reactant;
wherein the tank is configured to supply the reactant in gaseous form to the fuel cell at a rate determined by the boiling-rate of the reactant; and wherein the heat source is configured to increase the boiling rate of the reactant to a level appropriate to supply the gaseous reactant to the fuel cell at substantially the operating-rate of flux.
- 2. The aircraft power system of claim 1, wherein the power system is configured for use in predetermined ambient conditions having a higher temperature than the temperature of the liquid reactant, and wherein the tank in insulated such that the boiling rate of the liquid reactant due to heat flux through the insulation is lower than the boiling-rate necessary to supply the gaseous reactant to the fuel cell at substantially the operating-rate of flux.
- 3. The aircraft power system of claim 2, wherein the power system is configured for use in stratospheric flight conditions.
- 4. The aircraft power system of claim 1, wherein the tank is configured to contain cryogenic hydrogen, and where the fuel cell is configured for a reactant of gaseous hydrogen.
- 5. The aircraft power system of claim 1, wherein the heat source is an electrical heating element.
- 6. The aircraft power system of claim 1, wherein the tank comprises:
an inner aluminum tank liner having an outer carbon layer; an outer aluminum tank liner having an outer carbon layer; and connectors extending between the inner and outer aluminum tank liners to maintain their relative positions with respect to each other;
wherein the volume between the inner and outer tank liners is evacuated to minimize heat transfer between the contents of the tank and the outside environment; and wherein the connectors are configured with holes in their walls to minimize direct heat-conduction between the contents of the tank and the outside environment.
- 7. A stratospheric aircraft to be powered by a reactant, comprising:
an airframe configured for stratospheric flight; and a power system for generating power form the reactant, the power system including:
a fuel cell configured to generate power using a gaseous form of the reactant, the fuel cell being configured to operate at a power-generation rate requiring the gaseous reactant to be supplied at an operating-rate of flux; and a tank configured for containing a liquid form of the reactant, wherein the tank includes a heat source for increasing a boiling-rate of the reactant; wherein the tank is configured to supply reactant to the fuel cell at a rate determined by the boiling-rate of the reactant; and wherein the heat source is configured to increase the boiling rate of the reactant to a level appropriate to supply the gaseous reactant to the fuel cell at substantially the operating-rate of flux.
- 8. An aircraft, comprising:
a hydrogen source; an oxygen source; and a fuel cell configured to combine hydrogen from the hydrogen source and oxygen from the oxygen source to generate power, wherein the fuel cell is configured to combine the hydrogen and the oxygen at less than one atmosphere of pressure.
- 9. The aircraft of claim 8, and further comprising an aircraft engine configured to provide thrust from the power generated by the fuel cell.
- 10. The aircraft of claim 8, wherein the aircraft is configured to operate in conditions equivalent to an altitude of 55,000-70,000 feet.
- 11. The aircraft of claim 8, wherein the fuel cell is configured to internally operate at approximately 2-3 psia.
- 12. An aircraft as recited in any of claims 7-11, and further comprising wing-mounted solar cells configured to support the fuel cell or battery power of the aircraft when the sun is illuminating the plane.
Parent Case Info
[0001] The present application claims priority from two U.S. provisional patent applications, Serial No. 60/194,137, filed Apr. 3, 2000, and Serial No. 60/241,713, filed Oct. 18, 2000, which are both incorporated herein by reference for all purposes.
Provisional Applications (2)
|
Number |
Date |
Country |
|
60194137 |
Apr 2000 |
US |
|
60241713 |
Oct 2000 |
US |
Divisions (1)
|
Number |
Date |
Country |
Parent |
09826424 |
Apr 2001 |
US |
Child |
10073828 |
Feb 2002 |
US |