Ocean thermal energy conversion (OTEC) system

• US 5,582,691 A
• Filed: 12/14/1993
• Issued: 12/10/1996
• Est. Priority Date: 12/14/1993
• Status: Expired due to Fees

• Current Assignee: PTP, L.P.
• Original Assignee: OTEC Developments
• Inventors: Coony, Jonathan d'E., Flynn, Robert J., Cicchetti, George J.
• Primary Examiner(s): Manoharan, Virginia
• Application Number:
  US08/166,005
• Time in Patent Office: 1,092 Days
• Field of Search: 202/197, 202/186, 202/160, 202/235, 203/10, 203/11, 203/2, 203/40, 203/88, 203/87, 203/4, 203/90, 203/100, 203/DIG. 8, 203/21, 203/DIG. 16, 203/DIG. 17, 203/DIG. 20, 203/DIG. 9, 159/2.1, 159/3, 159/DIG. 16, 159/DIG. 31, 159/DIG. 32, 159/DIG. 38, 159/23, 159/902, 60/398, 60/641.7, 60/648, 60/651
• US Class Current: 203/11
• CPC Class Codes: B01D 1/305 Demister (vapour-liquid separation)
• CPC Class Codes: B01D 3/06 Flash distillation
• CPC Class Codes: C02F 1/04 by distillation or evaporation
• CPC Class Codes: F03G 7/05 Ocean thermal energy conversion, i.e. OTEC
• CPC Class Codes: Y02A 20/124 Water desalination
• CPC Class Codes: Y02E 10/30 Energy from the sea, e.g. using wave energy or salinity gradient
• CPC Class Codes: Y10S 159/31 Deaeration
• CPC Class Codes: Y10S 159/32 Indirect heat exchange
• CPC Class Codes: Y10S 159/38 Seed
• CPC Class Codes: Y10S 203/08 Waste heat
• CPC Class Codes: Y10S 203/09 Plural feed
• CPC Class Codes: Y10S 203/17 Saline water conversion
• CPC Class Codes: Y10S 203/18 Control
• CPC Class Codes: Y10S 203/21 Acrylic acid or ester

Abstract

An improved ocean thermal energy conversion (OTEC) system which includes a novel combined evaporator/condenser. The combined evaporator/condenser further includes a plurality of evaporator spouts and a mist eliminator, wherein the pressure is maintained across the plurality of evaporator spouts. The OTEC system also generates fresh water as a primary product and generates only enough electricity, as a secondary product, to operate the OTEC system itself.

Claims

1. An ocean thermal energy conversion (OTEC) system, comprising:

warm sea water receiving means for receiving a warm sea water supply from an ocean

cold sea water receiving means for receiving a cold sea water supply from the ocean,

warm sea water dividing means for dividing the warm sea water supply into a first and a second warm sea water stream,

cold sea water dividing mans for dividing the cold sea water supply into a first and a second cold sea water stream;

desalination means for receiving the first warm sea water stream, flash evaporating a portion of the first warm sea water stream, to produce steam, and condensing the steam by indirect contact with the first cold sea water stream to produce fresh water; and

energy generation means for receiving the second warm sea water stream, evaporating a working fluid, by indirect contact with the second warm sea water stream, to produce a working vapor, generating energy from the working vapor, and condensing the working vapor by indirect contact with the second cold sea water stream;

said desalination means further producing a cold sea water discharge and a warm sea water discharge which are not mixed with the second warm sea water stream and the second cold sea water stream received by said energy generation means;

said desalination means including,

flash evaporation means for receiving the first warm sea water stream and flash evaporating the portion of the first warm sea water stream to produce the steam,

a mist eliminator for removing mist from the steam, and

first condenser means for condensing the steam with the first cold sea water stream to produce the fresh water;

said energy generation means including,

evaporation means for receiving the second warm second water stream and evaporating the working fluid to produce the working vapor,

turbine means for generating the energy from the working vapor, and

second condenser means of condensing the working vapor with the second cold sea water stream.

2. The OTEC system of claim 1, wherein said desalination means is an open-cycle desalination system and wherein said energy generation means is a closed cycle energy system.

3. The OTEC system of claim 1, wherein a primary product of said OTEC system is the fresh water produced by said desalination means.

4. The OTEC system of claim 1, wherein said energy generation means generates enough energy to operate said OTEC system.

5. The OTEC system of claim 1, further comprising:

a single housing for housing said flash evaporation means, said mist eliminator, and said first condenser means.

6. The OTEC system of claim 1, further comprising:

a predeaeration chamber for removing non-condensible gases from the first warm sea water.

7. The OTEC system of claim 6, said predeaeration chamber including a baffle for indirectly routing the first warm sea water stream through said desalination means.

8. The OTEC system of claim 6, further comprising:

seed bubble injection means for injecting seed bubbles into said predeaeration chamber to facilitate evolution of the non-condensible gases.

9. The OTEC system of claim 8, said seed bubble injection means injecting the seed bubbles into said predeaeration chamber from the first warm sea water stream.

10. The OTEC system of claim 8, said seed bubble injection means injecting the seed bubbles into said predeaeration chamber from the atmosphere.

11. The OTEC system of claim 8, said seed bubble injection means injecting the seed bubbles into said predeaeration chamber from the warm sea water discharge.

12. The OTEC system of claim 11, said seed bubble injection means including horizontal piping for creating a region of zero vertical velocity.

13. The OTEC system of claim 11, said seed bubble injection means including stagnant means for creating a stagnant region in the warm sea water discharge.

14. The OTEC system of claim 13, wherein said stagnant means is a baffle.

15. The OTEC system of claim 13, wherein said stagnant means is a discharge pipe with a decreasing diameter.

16. The OTEC system of claim 1, said flash evaporation means including a plurality of evaporation spouts for flash evaporating the portion of the first warm sea water stream to produce the steam.

17. The OTEC system of claim 16, further comprising:

vertical static head pressure regulation means for controlling a pressure at each of said plurality of evaporation spouts.

18. The OTEC system of claim 1, wherein said mist eliminator is a chevron-style mist eliminator.

19. A method of generating fresh water, comprising the steps of:

(a) receiving a warm sea water supply from an ocean;

(b) receiving a cold sea water supply from the ocean;

(c) dividing the warm sea water supply into a first and a second warm sea water stream;

(d) dividing the cold sea water supply into a first and a second cold sea water stream;

(e) flash evaporating a portion of the first warm sea water stream to produce steam;

(f) removing mist from the steam;

(g) condensing the steam by indirect contact with the first cold sea water stream to produce fresh water;

(h) evaporating a working fluid by indirect contact with the second warm sea water stream to produce a working vapor;

(i) generating energy from the working vapor and condensing the working vapor by indirect contact with the second cold sea water stream;

wherein said steps (e) and (g) also produce a warm sea water discharge and a cold sea water discharge, respectively, which are not mixed with the second warm sea water stream of said step (h) and the second cold sea water stream of said step (i), respectively.

20. The method of claim 19, wherein a primary product of said method is the fresh water produced in said step (g).

21. The method of claim 19, wherein the energy generated in said step (i) is sufficient to operate an OTEC system which performs said method.