Phase change material thermal power generator

• US 7,987,674 B2
• Filed: 05/01/2008
• Issued: 08/02/2011
• Est. Priority Date: 05/09/2007
• Status: Active Grant

• Current Assignee: California Institute of Technology
• Original Assignee: California Institute of Technology
• Inventors: Valdez, Thomas I., Chao, Yi, Jones, Jack A.
• Primary Examiner(s): Nguyen; Hoang M
• Application Number:
  US12/113,882
• Publication Number:
  US 20090013691A1
• Time in Patent Office: 1,188 Days
• Field of Search: 60527-531
• US Class Current: 60/641.7
• CPC Class Codes: F03G 7/05 Ocean thermal energy conversion, i.e. OTEC
• CPC Class Codes: Y02E 10/30 Energy from the sea, e.g. using wave energy or salinity gradient

Abstract

An energy producing device, for example a submersible vehicle for descending or ascending to different depths within water or ocean, is disclosed. The vehicle comprises a temperature-responsive material to which a hydraulic fluid is associated. A pressurized storage compartment stores the fluid as soon as the temperature-responsive material changes density. The storage compartment is connected with a hydraulic motor, and a valve allows fluid passage from the storage compartment to the hydraulic motor. An energy storage component, e.g. a battery, is connected with the hydraulic motor and is charged by the hydraulic motor when the hydraulic fluid passes through the hydraulic motor. Upon passage in the hydraulic motor, the fluid is stored in a further storage compartment and is then sent back to the area of the temperature-responsive material.

Claims

1. A submersible vehicle adapted to descend or ascend to different depths within water or ocean, the submersible vehicle comprising an energy producing device, the energy product device comprising:

a temperature-responsive material adapted to undergo density changes in response to temperature changes;

a hydraulic fluid operatively associated with the temperature-responsive material, the hydraulic fluid adapted to be controlled within the energy producing device in accordance with the density changes of the temperature-responsive material;

a first pressurized storage compartment configured to store the hydraulic fluid upon the density change of the temperature-responsive material;

a hydraulic motor fluidically connected with the first pressurized storage compartment;

a first valve adapted to allow hydraulic fluid passage from the first pressurized storage compartment to the hydraulic motor;

an energy storage component connected with the hydraulic motor, the energy storage component being chargeable by the hydraulic motor upon passage of the hydraulic fluid through the hydraulic motor thus obtaining conversion of hydraulic energy to electrical energy; and

a second pressurized storage compartment configured to store the hydraulic fluid after passage of the hydraulic fluid in the hydraulic motor,

wherein the electrical energy is adapted to be used to power the submersible vehicle, the submersible vehicle further comprising a bladder external to the submersible vehicle, the bladder being connected to the second pressurized storage compartment, wherein the hydraulic fluid is adapted to be controllably fed to the bladder to control buoyancy of the submersible vehicle.

2. The submersible vehicle of claim 1, further comprising a second valve between the second pressurized storage compartment and the bladder, the second valve controlling feeding of the hydraulic fluid to the bladder and/or return of the hydraulic fluid from the second pressurized storage compartment to a region of the submersible vehicle under control of the temperature-responsive material.

3. The submersible vehicle of claim 1, wherein the density change corresponds to expansion or contraction of the temperature-responsive material.

4. The submersible vehicle of claim 1, wherein the density change corresponds to a phase change of the temperature-responsive material.

5. The submersible device of claim 1, adapted to undergo a first operative condition where the hydraulic fluid is fed to the bladder to cause the submersible device to rise, a second operative condition where the hydraulic fluid is fed from the bladder to the second pressurized storage compartment to cause the submersible device to descend, and a third operative condition where the hydraulic fluid is fed from the second pressurized storage compartment back to a region of the energy producing device under control of the temperature-responsive material.

6. The submersible device of claim 5, wherein the hydraulic fluid fed to the bladder passes through the hydraulic motor.

7. The submersible device of claim 5, wherein the hydraulic fluid fed to the bladder bypasses the hydraulic motor.

8. The submersible vehicle of claim 1, further comprising a third valve adapted to allow hydraulic fluid return from the second pressurized storage compartment to a region of the submersible vehicle under control of the temperature-responsive material.

9. The submersible vehicle of claim 1, further comprising a fourth valve adapted to prevent return of the hydraulic fluid from the first pressurized storage compartment to a region of the submersible vehicle under control of the temperature-responsive material.