Method and apparatus for converting heat from geothermal liquid and geothermal steam to electric power

• US 5,440,882 A
• Filed: 11/03/1993
• Issued: 08/15/1995
• Est. Priority Date: 11/03/1993
• Status: Expired due to Term

• Current Assignee: Global Geothermal Limited (Kalina Power Limited)
• Original Assignee: Exergy S.P.A.
• Inventors: Kalina, Alexander I.
• Primary Examiner(s): Lazarus, Ira S.
• Assistant Examiner(s): HEYMAN, LEONARD
• Application Number:
  US08/147,670
• Time in Patent Office: 650 Days
• Field of Search: 60/641.2, 60/641.5, 60/651, 60/671, 60/677, 60/655
• US Class Current: 60/641.2
• CPC Class Codes: F01K 23/04 condensation heat from one cycle heating the fluid in another cycle
• CPC Class Codes: F01K 25/06 using mixtures of different fluids plants using mixtures of steam and gas F01K21/04
• CPC Class Codes: F03G 7/04 using pressure differences or thermal differences occurring in nature F03G7/06 takes precedence
• CPC Class Codes: Y02E 10/10 Geothermal energy

Abstract

A method and apparatus for implementing a thermodynamic cycle that includes: (a) expanding a gaseous working stream, transforming its energy into usable form and producing a spent working stream; (b) heating a multicomponent oncoming liquid working stream by partially condensing the spent working stream; and (c) evaporating the heated working stream to form the gaseous working stream using heat produced by a combination of cooling geothermal liquid and condensing geothermal steam.

Claims

1. A method of implementing a thermodynamic cycle comprising the steps of:

expanding a gaseous working stream, transforming its energy into usable form and producing a spent working stream;

heating a multicomponent oncoming liquid working stream by partially condensing the spent working stream, thereby forming a preheated liquid working stream; and

further comprising the steps of;

dividing the preheated liquid working stream into first and second substreams;

partially evaporating the first substream using heat produced by partially condensing the spent working stream;

partially evaporating the second substream using heat produced by cooling geothermal liquid;

combining the partially evaporated first and second substreams; and

evaporating the partially evaporated first and second substreams to form the gaseous working stream using heat produced by a combination of cooling geothermal liquid and condensing geothermal steam.

2. The method of claim 1 wherein the initial boiling temperatures of the first and second substreams are the same, and the difference between the initial boiling temperature of the second substream and the temperature of the geothermal liquid is greater than the difference between the initial boiling temperature of the first substream and the temperature of the condensed spent working stream.

3. A method of implementing a thermodynamic cycle comprising the steps of:

expanding a gaseous working stream, transforming its energy into usable form and producing a spent working stream;

heating a multicomponent oncoming liquid working stream by partially condensing the spent working stream; and

evaporating the heated working stream to form the gaseous working stream using heat produced by a combination of cooling geothermal liquid and condensing geothermal steam,

further comprising the step of;

expanding geothermal steam, transforming its energy into usable form and producing a spent geothermal stream; and

wherein said evaporating includes;

condensing the spent geothermal stream to heat and partially evaporate the heated working stream; and

further comprising;

combining the spent geothermal stream with the cooled geothermal liquid.

4. A method of implementing a thermodynamic cycle comprising the steps of:

expanding a gaseous working stream, transforming its energy into usable form and producing a spent working stream;

heating a multicomponent oncoming liquid working stream by partially condensing the spent working stream; and

evaporating the heated working stream to form the gaseous working stream using heat produced by a combination of cooling geothermal liquid and condensing geothermal steam,

further comprising the steps of;

expanding geothermal steam, transforming its energy into usable form and producing a spent geothermal stream;

dividing the spent geothermal stream into first and second geothermal substreams; and

wherein said evaporating includes;

condensing the first geothermal substream to heat and partially evaporate the heated working stream; and

further comprising;

combining the first geothermal substream with the geothermal liquid;

expanding the second geothermal substream, transforming its energy into usable form and producing a further spent geothermal substream; and

wherein said evaporating includes;

condensing the further spent geothermal substream to heat and partially evaporate the heated working stream; and

further comprising;

combining the further spent geothermal substream with the geothermal liquid.

5. A method of implementing a thermodynamic cycle comprising the steps of:

expanding a gaseous working stream, transforming its energy into usable form and producing a spent working stream;

preheating an oncoming multicomponent liquid working stream by partially condensing the spent working stream;

dividing the preheated liquid working stream into first and second substreams;

partially evaporating the first substream using heat produced by partially condensing the spent working stream;

partially evaporating the second substream using heat produced by cooling geothermal liquid;

combining the partially evaporated first and second substreams;

evaporating the partially evaporated first and second substreams using heat produced by a combination of cooling geothermal liquid and condensing geothermal stream; and

superheating the evaporated liquid working stream using heat produced by cooling geothermal liquid to form the gaseous working stream.

6. The method of claim 5 wherein the initial boiling temperatures of the first and second substreams are the same, and the difference between the initial boiling temperature of the second substream and the temperature of the geothermal liquid is greater than the difference between the initial boiling temperature of the first substream and the temperature of the condensed spent working stream.

7. The method of claim 5 further comprising the step of:

expanding geothermal steam, transforming its energy into usable form and producing a spent geothermal stream; and

wherein said evaporating includes;

condensing the spent geothermal stream to heat and partially evaporate the liquid working stream; and

further comprising;

combining the spent geothermal stream with the geothermal liquid.

8. The method of claim 5 further comprising the steps of:

expanding geothermal steam, transforming its energy into usable form and producing a spent geothermal stream;

dividing the spent geothermal stream into first and second geothermal substreams; and

wherein said evaporating includes;

condensing the first geothermal substream to heat and partially evaporate the liquid working stream; and

further comprising;

combining the first geothermal substream with the geothermal liquid;

expanding the second geothermal substream, transforming its energy into usable form and producing a spent geothermal substream; and

wherein said evaporating further includes;

condensing the spent geothermal substream to heat and partially evaporate the liquid working stream; and

further comprising;

combining the spent geothermal substream with the geothermal liquid.

9. Apparatus for implementing a thermodynamic cycle comprising:

means for expanding a gaseous working stream, transferring its energy into usable form and producing a spent stream;

a first heat exchanger connected to receive said spent stream for partially condensing the spent stream and for transferring heat from the spent stream to an oncoming multicomponent liquid working stream, resulting in a heated liquid working stream;

a stream separator connected to receive said heated liquid working stream from said first heat exchanger for dividing the heated liquid working stream into first and second substreams;

a second heat exchanger connected to receive said first substream from said stream separator and to receive said spent stream from said means for expanding and to provide said spent stream to said first heat exchanger for partially condensing the spent working stream and transferring heat from the spent working stream to partially evaporate the first substream;

a third heat exchanger connected to receive said second substream from said stream separator and to receive a geothermal liquid for cooling the geothermal liquid and transferring heat from the geothermal liquid to partially evaporate the second substream; and

a stream mixer connected to receive and combine the partially evaporated first and second substreams from said second and third heat exchangers, resulting in a partially evaporated recombined working stream;

a geofluid separator for separating geofluid into geothermal liquid and geothermal steam; and

a multiplicity of heat exchangers connected to receive said geothermal liquid and said geothermal steam from said geofluid separator and said partially evaporated recombined working stream for cooling said geothermal liquid and condensing said geothermal steam, and for transferring heat from the geothermal liquid and geothermal steam to evaporate said partially evaporated working stream and form the gaseous working stream, said further heat exchangers being connected so that said gaseous working stream is provided to said means for expanding and said geothermal liquid is provided to said third heat exchanger.

10. Apparatus for implementing a thermodynamic cycle comprising:

means for expanding a gaseous working stream, transferring its energy into usable form and producing a spent stream;

a first heat exchanger connected to receive said spent stream for partially condensing the spent stream and for transferring heat from the spent stream to an oncoming multicomponent liquid working stream;

a geofluid separator for separating geofluid into geothermal liquid and geothermal steam;

first means for expanding geothermal steam from said geofluid separator, transforming its energy into usable form and producing a first spent geothermal stream;

a stream separator for dividing the first spent geothermal stream from said first means for expanding geothermal steam into first and second geothermal substreams;

a second heat exchanger connected to said stream separator for receiving the first geothermal substream and condensing the first geothermal substream into a condensed first geothermal substream and transferring heat from the first geothermal substream to partially evaporate the working stream;

a first stream mixer connected to combine the condensed first geothermal substream with the geothermal liquid;

second means for expanding the second geothermal substream, transforming its energy into usable form and producing a second spent geothermal substream;

a third heat exchanger connected to said second means for expanding the second geothermal substream for receiving the second geothermal substream and condensing the second spent geothermal substream and transferring heat from the second spent geothermal substream to partially evaporate the working stream;

a second stream mixer connected to combine the second spent geothermal substream with the geothermal liquid, and

a multiplicity of further heat exchangers connected to receive said geothermal liquid for cooling said geothermal liquid and for transferring heat from the geothermal liquid to the working stream to heat and evaporate the working stream and form the gaseous working stream, said further heat exchangers being connected so that said gaseous working stream is provided to said means for expansion.

11. Apparatus for implementing a thermodynamic cycle comprising:

means for expanding a gaseous working stream, transferring its energy into usable form and producing a spent stream;

a first heat exchanger connected to receive said spent stream for partially condensing the spent stream and for transferring heat from the spent stream to an oncoming multicomponent liquid working stream, resulting in a preheated liquid working stream;

a geofluid separator for separating geofluid into geothermal liquid and geothermal steam;

a stream separator connected to receive said preheated liquid working stream for dividing the heated liquid working stream into first and second substreams;

a second heat exchanger connected between said means for expanding and said first heat exchanger for partially condensing the spent working stream and also connected to said stream separator for transferring heat from the spent working stream to partially evaporate the first substream;

a third heat exchanger for cooling the geothermal liquid and connected to said stream separator for transferring heat from the cooled geothermal liquid to partially evaporate the second substream;

a stream mixer connected to said second and third heat exchangers for combining the partially evaporated first and second substreams;

a multiplicity of further heat exchangers connected to said geofluid separator to receive said geothermal liquid and said geothermal steam for cooling said geothermal liquid and condensing said geothermal steam, and for transferring heat from the geothermal liquid and geothermal steam to evaporate the working stream; and

a still further heat exchanger for cooling geothermal liquid and transferring heat from the geothermal liquid to superheat the working stream and form the gaseous working stream.

12. The apparatus of claim 11 further comprising:

means for expanding said geothermal steam from said geofluid separator, transforming its energy into usable form and producing a spent geothermal stream;

and where one of said further heat exchangers is connected to receive said spent geothermal stream and condense the spent geothermal stream and transfer heat from the spent geothermal stream to partially evaporate the working stream, resulting in a condensed geothermal stream; and

a stream mixer connected to receive said condensed geothermal stream from the last mentioned heat exchanger for combining the condensed geothermal stream with the geothermal liquid.

13. The apparatus of claim 11 comprising:

means for expanding said geothermal steam from said geofluid separator, transforming its energy into usable form and producing a first spent geothermal stream;

a spent geothermal stream separator for dividing the first spent geothermal stream from said means for expanding said geothermal steam into first and second geothermal substreams; and

wherein one of said multiplicity of further heat exchangers comprises;

a heat exchanger connected to said spent geothermal stream separator for receiving the first geothermal substream and condensing the first geothermal substream into a condensed first geothermal substream and transferring heat from the first geothermal substream to partially evaporate the working stream; and

further comprising;

a first geothermal stream mixer connected to combine the condensed first geothermal substream with the geothermal liquid;

means for expanding the second geothermal substream, transforming its energy into usable form and producing a second spent geothermal substream; and

wherein one of said multiplicity of further heat exchangers comprises;

a heat exchanger connected to said means for expanding the second geothermal substream for receiving the second spent geothermal substream and condensing the second spent geothermal substream and transferring heat from the second spent geothermal substream to partially evaporate the working stream; and

a second geothermal stream mixer for combining the second spent geothermal substream with the geothermal liquid.

14. A method of implementing a thermodynamic cycle comprising the steps of:

separating a geofluid into geothermal liquid and geothermal steam,

heating a working stream to its highest temperature in a working cycle by cooling said geothermal liquid, resulting in a cooled geothermal liquid and a gaseous working stream of highest temperature,

expanding said geothermal steam, transforming its energy into usable form, and producing a spent geothermal stream,

heating said working stream to a middle temperature by condensing said spent geothermal stream, resulting in a condensed geothermal stream having a temperature that is substantially equal to the temperature of said cooled geothermal liquid,

combining said cooled geothermal liquid and said condensed geothermal stream to provide a recombined geothermal stream,

heating said working stream from a lower temperature below said middle temperature by cooling said recombined geothermal stream,

expanding said gaseous working stream of highest temperature, transforming its energy into usable form, and producing a spent working stream, and

condensing said spent working stream to provide an oncoming liquid working stream.

15. The method of claim 14 wherein said working stream is a multicomponent fluid, and further comprising preheating said oncoming liquid working stream by partially condensing said spent working stream.

18. The method of claim 14 wherein said spent geothermal stream is split into a first substream and a second substream, and said condensing said spent geothermal stream is condensing of said first substream, and further comprising,

expanding said second substream, transforming its energy into usable form, and producing a spent second substream,

heating said working stream from a temperature below said lower temperature by condensing said spent second substream.

16. Apparatus for implementing a thermodynamic cycle comprising:

a geofluid separator for separating geofluid into geothermal liquid and geothermal steam,

a first heat exchanger connected to receive said geothermal liquid from said geofluid separator and to receive a working stream and to output a gaseous working stream of highest temperature and a cooled geothermal liquid,

means for expanding said geothermal steam from said geofluid separator, transforming its energy into usable form and producing a spent geothermal stream,

a second heat exchanger connected to receive said spent geothermal stream from said means for expanding and to receive said working stream at a lower temperature, said second heat exchanger condensing said spent geothermal stream and heating said working stream at said lower temperature, resulting in a condensed geothermal stream having a temperature that is substantially equal to the temperature of said cooled geothermal liquid and a working stream heated to a middle temperature that is lower than said highest temperature,

a stream mixer connected to receive and combine said condensed geothermal stream from said second heat exchanger and said cooled geothermal liquid from said first exchanger and provide a recombined geothermal stream,

a third heat exchanger connected to receive said recombined geothermal stream and connected to receive said working fluid and to heat said working fluid from a temperature below said lower temperature by cooling said recombined geothermal stream,

means for expanding said gaseous working stream received from said first heat exchanger, transferring its energy into usable form and producing a spent working stream, and

a condenser connected to receive said spent working stream and to condense said spent working stream and provide an oncoming liquid working stream.

17. The apparatus of claim 16 wherein said working stream is a multicomponent fluid, and further comprising:

a fourth heat exchanger connected to receive said oncoming liquid working stream from said condenser and said spent working stream and to preheat said oncoming liquid working stream, partially condensing said spent working stream.

19. The apparatus of claim 16 further comprising a stream splitter that splits said spent geothermal stream into a first substream and a second substream, and wherein said spent geothermal stream received by said second heat exchanger is said first substream, and further comprising,

means for expanding said second substream from said stream splitter, transforming its energy into usable form, and producing a spent second substream, and

a fourth heat exchanger connected to receive said spent second substream from said means for expanding said second substream and to receive said working stream at a temperature below said lower temperature, said fourth heat exchanger condensing said spent second substream and heating said working stream at a temperature below said lower temperature.