Sea water desalination and thermal energy conversion

1. A system comprising:

a first sub-system to be disposed at or near a surface of an ocean, the first sub-system including an evaporation unit;

a second sub-system to be disposed at an ocean depth of at least 500 meters;

a turbine;

a pump disposed between the turbine and the second sub-system; and

a collection tank coupled to the second sub-system,

wherein:

the evaporation unit is configured to vaporize a working fluid comprising seawater by use of heat from fluid located at or near the surface of the ocean that is at a temperature sufficient to vaporize the working fluid,

the turbine is configured to turn in response to receipt of the vaporized working fluid,

the pump is configured to pump the vaporized working fluid from the turbine to the second sub-system at the ocean depth,

the second sub-system is configured to condense the working fluid with seawater located adjacent to the second sub-system at the ocean depth to produce desalinated water, and

the collection tank is configured to collect the desalinated water from the second sub-system.

2. The system of claim 1 wherein at least a portion of the turbine is incorporated in the first sub-system.

3. The system of claim 1 wherein the evaporation unit comprises an inlet and an outlet to flow seawater through a first heat exchange unit.

4. The system of claim 1 wherein:

the evaporation unit is configured to vaporize the seawater to produce water vapor; and

the second sub-system is configured to condense the water vapor to produce the desalinated water.

5. The system of claim 4 wherein the evaporation unit comprises an evaporator in thermal communication with seawater that flows through a first heat exchange unit.

6. The system of claim 4 wherein the second sub-system comprises a pipe configured to condense the vaporized working fluid.

7. The system of claim 5 wherein the evaporator comprises:

an evaporator input port to receive seawater; and

first and second evaporator output ports, the first evaporator output port is coupled to the turbine and the second evaporator output port is in communication with the ocean.

8. The system of claim 6 wherein water vapor passes to the turbine through the first evaporator output port and unvaporized seawater returns to the ocean through the second evaporator output port.

9. The system of claim 1 wherein the evaporation unit comprises an evaporator in thermal communication with seawater that flows through the evaporation unit.

10. The system of claim 1 wherein at least a portion of the pump is incorporated in the second sub-system.

11. The system of claim 1 wherein at least a portion of the pump is positioned between the first sub-system and the second sub-system.

12. A method to convert energy from an ocean comprising:

vaporizing a working fluid comprising seawater by a first heat exchange unit of a first sub-system located at or near a surface of the ocean by use of heat from fluid located at or near the surface of the ocean that is at a temperature sufficient to vaporize the working fluid;

using the vaporized working fluid to produce work;

directing the vaporized working fluid to a second sub-system located at an ocean depth of at least 500 meters, wherein a second heat exchanger condenses the vaporized working fluid with seawater located adjacent to the second sub-system to produce desalinated water; and

directing the desalinated water to a collection tank.

13. The method of claim 12 wherein using the vaporized working fluid to produce work comprises using the vaporized working fluid to turn a turbine to generate electricity.

14. A method to desalinate seawater comprising:

vaporizing seawater to form water vapor with an evaporation unit of a first sub-system located at or near a surface of the ocean by use of heat from fluid located at or near the surface of the ocean that is at a temperature sufficient to vaporize the seawater;

using the vaporized seawater to produce work;

directing the vaporized seawater to a second sub-system located at an ocean depth of at least 500 meters, wherein the second sub-system condenses the vaporized seawater with seawater located adjacent to the second sub-system to produce desalinated water; and

directing the desalinated water to a collection tank.

15. The method of claim 14 wherein vaporizing seawater with the evaporation unit includes flowing seawater through an inlet and an outlet of the evaporation unit.