Geothermal energy system and method of producing power using same

Abstract

A geothermal energy system utilizes supercritical CO2 turbine and a radial outflow reaction turbine, a Catherine Wheel having wheel arms, that spins around an axle to produce power. A fin portion extends from the radial portion at an offset angle, to an exhaust end. A first working fluid, such as supercritical carbon dioxide flows through an arm conduit within the wheel arm and a second working fluid, such as a hydrocarbon mixes with the first working fluid and both flow through a turbine. The turbine may be configured within the wheel arm conduit or mounted prior to the Catherine Wheel or any other radial outflow reaction turbine, or variable phase turbines available, and it turns as the combined working fluids expand and vaporize. The second working fluid may be condensed and recirculated while the first working fluid is expelled back into a geothermal reservoir.

Claims

1. A geothermal energy system comprising: a) a Catherine Wheel that spins around an axle and comprising: i) a plurality of wheel arms configured around an axle, wherein each of the plurality of wheel arms comprises: a radial portion a fin portion, wherein the radial portion extends radially out from an axle end and wherein the fin portion extends from the radial portion at an offset angle to an exhaust end an arm conduit extending within the wheel arm to said exhaust end; a turbine positioned within the arm conduit; wherein a first working fluid flows through the arm conduit and into said turbine; wherein a second working fluid is introduced into said turbine, and wherein the first working fluid and second working fluid are mixed and are vaporized within the turbine to form a vaporized working fluid that is expelled from the exhaust end of the wheel arm to propel the wheel arm and the Catherine wheel about the axle; ii) wherein the first working fluid heats the second working fluid; b) an electrical power generator coupled with the Catherine Wheel that produces electrical power when the Catherine wheel spins about the axle; c) a condenser that receives the vaporized working fluid and separates the working fluid back into said first and second working fluid components.

2. The geothermal energy system of claim 1, wherein the first working fluid is heated before flowing into the turbine.

3. The geothermal energy system of claim 2, wherein the first working fluid is heated in the wheel arm.

4. The geothermal energy system of claim 2, wherein the first working fluid is heated to a supercritical state before being introduced into the turbine.

5. The geothermal energy system of claim 1, wherein the second working fluid is recirculated from the condenser back to the Catherine Wheel.

6. The geothermal energy system of claim 1, further comprising a) an extraction conduit extending from a geothermal reservoir that produces an inlet flow of the first working fluid component to the arm conduit of the Catherine Wheel.

7. The geothermal energy system of claim 6, further comprising an injection conduit extending into said geothermal reservoir to produce an outlet flow of said first working fluid component back into the geothermal reservoir.

8. The geothermal energy system of claim 1, wherein the second working fluid is recirculated from the condenser to a second fluid reservoir.

9. The geothermal energy system of claim 1, wherein the second working fluid component of the vaporized working fluid is condensed to a liquid and wherein said liquid is atomized and injected into a compressor to improve efficiency of said compressor.

10. The geothermal energy system of claim 1, wherein the first working fluid component comprises carbon dioxide.

11. The geothermal energy system of claim 1, wherein the first working fluid component is supercritical CO2 when introduced into the arm conduit.

12. The geothermal energy system of claim 1, wherein the second working fluid comprises a hydrocarbon having a vapor pressure of at least 0.75 MPa.

13. The geothermal energy system of claim 12, wherein the second working fluid is propane.

14. The geothermal energy system of claim 13, wherein the vaporized working fluid has a working fluid mix ratio of first working fluid to second working fluid of at least 4 to 1.

15. The geothermal energy system of claim 12, wherein the second working fluid is isobutane.

16. The geothermal energy system of claim 15, wherein the vaporized working fluid has a working fluid mix ratio of first working fluid to second working fluid of at least 3 to 1.

17. The geothermal energy system of claim 1, wherein the second working fluid flows through a second fluid delivery conduit and wherein the second fluid delivery conduit couples with the arm conduit at a second fluid inlet.

18. The geothermal energy system of claim 17, wherein the second fluid inlet is configured at least 50% of the wheel arm length from the axle end of the wheel arm.

19. The geothermal energy system of claim 1, wherein the Catherine Wheel has a diameter of at least 3 meters.

20. The geothermal energy system of claim 1, wherein the Catherine Wheel has a diameter of at least 10 meters.

Description

BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS

(1) The accompanying drawings are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention, and together with the description serve to explain the principles of the invention.

(2) FIG. 1 shows a perspective view of exemplary geothermal energy system comprising a Catherine Wheel that spins to produce electricity.

(3) FIG. 2 shows a bottom view of exemplary geothermal energy system comprising a Catherine Wheel that spins to produce electricity.

(4) FIG. 3 shows a bottom view of a Catherine wheel and exhaust ring.

(5) FIG. 4 shows a perspective view of a wheel arm having an arm conduit for a first working fluid comprising carbon dioxide extracted from the geothermal reservoir and a second fluid deliver conduit for injecting the second working fluid into the arm conduit for deliver to the turbine.

(6) FIG. 5 show a side view of a portion of an exemplary Catherine wheel having a heater configured to heat the first working fluid as it passes through the arm conduit.

(7) FIG. 6 show a schematic of an exemplary geothermal energy system comprising a Catherine wheel.

(8) FIG. 7 shows a cross sectional view of an exemplary turbine having a mixing chamber, diffuser and evaporator combined in a single unit for vaporizing the first and second working fluids.

(9) FIG. 8 shows an exemplary wheel arm having a De Laval Nozzle, or a convergent subsonic nozzle, in the radial portion.

(10) Corresponding reference characters indicate corresponding parts throughout the several views of the figures. The figures represent an illustration of some of the embodiments of the present invention and are not to be construed as limiting the scope of the invention in any manner. Further, the figures are not necessarily to scale, some features may be exaggerated to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present invention.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

(11) As used herein, the terms “comprises,” “comprising,” “includes,” “including,” “has,” “having” or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a process, method, article, or apparatus that comprises a list of elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Also, use of “a” or “an” are employed to describe elements and components described herein. This is done merely for convenience and to give a general sense of the scope of the invention. This description should be read to include one or at least one and the singular also includes the plural unless it is obvious that it is meant otherwise.

(12) Certain exemplary embodiments of the present invention are described herein and are illustrated in the accompanying figures. The embodiments described are only for purposes of illustrating the present invention and should not be interpreted as limiting the scope of the invention. Other embodiments of the invention, and certain modifications, combinations and improvements of the described embodiments, will occur to those skilled in the art and all such alternate embodiments, combinations, modifications, improvements are within the scope of the present invention.

(13) Referring FIGS. 1 and 2, an exemplary geothermal energy system 10 comprises a Catherine Wheel 50 that spins about a rotational axis 55 to produce power in a generator 53 coupled thereto. The Catherine wheel comprises a plurality of wheel arms 60 that comprise an arm conduit 66 for the flow of a first working fluid comprising carbon dioxide extracted from an extraction well 16 coupled with a geothermal reservoir 14 which may be below ground 12. A second working fluid, such as a hydrocarbon is introduced into the arm conduit 66 through a second fluid delivery conduit 38, and the two working fluids then pass through a turbine 90. The two fluids vaporize, expand and are accelerated from the turbine unit to produce propulsion of the wheel arm as the working fluids flow out from the exhaust end of the wheel arm. The wheel arms have a radial portion 61 that extends radially from the axle 52 of the Catherine wheel, and a fin portion 70 that is at an offset angle to the radial portion. The first working fluid flows from the geothermal reservoir 14 through the extraction well conduit 14, and may be compressed by compressor 42 before being delivered to the wheel arms of the Catherine wheel. Note that the first working fluid, such as super-critical CO2 may be heated prior to deliver to the wheel arms. The second working fluid, such as a hydrocarbon flow from the second fluid container into the second fluid deliver conduits 38, extending along each of the wheel arms. The force of the working fluids flowing out from the exhaust end turns the Catherine wheel and a generator 53 coupled to the Catherine wheel axle 52, such as by one or more gears produces power. The expelled gasses from the exhaust end of the Catherine wheel is captured in the exhaust ring 56 and fed through a separator 49 to a cooler/condenser. The second working fluid is returned to the second working fluid container 34 through a return conduit 36 and the first working fluid flows through the first working fluid exhaust conduit 28 to the injection tube 29. The first working fluid flow from the injection tube 29 back to the geothermal reservoir through a return well conduit 18. In a real geothermal power plant application, the return well conduit and fluid extraction conduit may be hundreds of meters apart.

(14) Referring to FIGS. 2 and 3, the wheel arms 60 have a radial portion 61 having a length 63 from an axle end 62 to the fin end 64, and a fin portion 70 having a length from the radial end to the exhaust end 74. The exhaust end may extend into the exhaust ring 56 and a dynamic seal 57 may seal around the wheel arm as it rotates within the exhaust ring. The radial portions 61 are designed in symmetry in order to cancel the centrifugal force, imparted on the embedded turbine units as shown in FIG. 7, by the spinning Catherine Wheel 50 and reduce the vibration. The increased plurality of wheel arms help to lower the vibration and stabilize the system. The Catherine wheel 50 has a diameter 51 that may be large as described herein. FIG. 3 shows a bottom view of a Catherine wheel 50 configured to exhaust into an exhaust ring 56. The wheel arm 60 has a radial portion that extends from an axel end 62 to an exhaust fin end 64. The wheel arm then turns to a fin portion 70 extending from the radial end 72 to the exhaust end 74. The exhaust end expels fluid into the exhaust ring 56. The wheel arm extends into the exhaust ring and stay strictly airtight with the space inside the ring slot. Thus, the tubes and nozzles very close to the ends of arms form a connecting vessel with the ring, from which there would be a successive pressure drops all the way from the mixing chamber to the exhaust ring.

(15) As shown in FIG. 4, an exemplary wheel arm 60 has an arm conduit 66 for a first working fluid 20 comprising carbon dioxide extracted from the geothermal reservoir and a second fluid deliver conduit 38 for injecting the second working fluid 30 into the arm conduit through the second fluid inlet 39, for deliver to the turbine 90. The two working fluids are vaporized in the turbine and are accelerated out from the exhaust end 74 of the fin portion 70 of the wheel arm. The turbine is located near the end of the radial portion 61 of the wheel arm, just before the radial end 72, or the curved portion 71 between the radial portion 61 and the fin portion 70. In an exemplary embodiment, supercritical carbon dioxide is mixed with the saturated liquid of the second working fluid. The second working fluid boils through contact with the supercritical carbon dioxide and both expand and vaporize. This step will be assisted by reheating, with the compression work generated by the gas turbine, or an electric heater powered by the electric motor embedded in the gas turbine. The combined vapor of the combined first and second working fluids drives the gas turbine to increase the enthalpy of the first working fluid, and thus the total enthalpy of the subsequent combined working fluid. The remaining high velocity expulsion of the combined working fluids from the exhaust end of the wheel arms, spins the Catherine wheel to produce electricity.

(16) As shown in FIG. 5, an exemplary Catherine wheel 50 has a heater 44 configured to heat the first working fluid 20 as it passes through the arm conduit 66.

(17) As shown in FIG. 6, an exemplary geothermal energy system 10 comprises a Catherine wheel 50 that spins or rotates about an axis to produce energy by a generator 40. A flow of a first working fluid 20 comprising carbon dioxide extracted through an extraction well 16 connected with a geothermal reservoir 14 and is compressed in a compressor 42. The compressed first working fluid is then mixed with a second working fluid 30 in a mixing chamber 41, which may comprise a heating device 43 to control the temperature of the mixed fluids. The second working fluid may also be heated with a heat exchanger. A valve 156 may regulate the flow of the second working fluid into the mixing chamber 41. The mixed second working fluid 30 and first working fluid 20 are vaporized or evaporated in an evaporation section 145 to produce a vaporized working fluid 15, which is then passed through a turbine 90 and out of the exhaust end of the wheel arm 60. The two fluids pass from the mixing chamber 41, through a diffuser 47 and an evaporator 80. Note that the mixing chamber, diffuser and evaporator maybe configured in a single unit or device. The mixed fluids then flow to a turbine and subsequently out of the exhaust end of a Catherine Wheel 50. As described herein, the turbine may be configured in the wheel arm of the Catherine Wheel. The rotating Catherine Wheel accelerates the vaporized working fluids and they are then compressed in a compressor 42 and then cooled and/or condensed in a condenser 48 and finally separated by a separator 49. The second working fluid 30′ is returned to a second working fluid reservoir 82 and recirculated through the system. The first working fluid 20′ flows back to the geothermal reservoir 14 through a return well conduit 18. Energy produced by the geothermal energy system 10 may be stored in an energy storage device 11, such as a Vanadium Redox Flow Cell or Battery. A power generator 40, such as a turbine, may also be coupled to the energy storage device to produce electrical power. The power may be generated by the rotation of the wheel.

(18) As shown in FIG. 7, an exemplary turbine 90 is configured to receive and vaporize the first working fluid 20 and second working fluid 30, The first working fluid 20 flows through the arm conduit 66 of the wheel arm 60 and into the inlet 92 of the turbine 90. The turbine is configured within the arm conduit 66. The second working fluid 30 flows through a second fluid delivery conduit 38 and into the turbine 90. The two working fluids mix and flow through the compression chamber 94 and are vaporized in the vaporization chamber 96 wherein the vaporized working fluids 25 accelerate out of the exhaust 98 of the turbine.

(19) As shown in FIG. 8, a De Laval Nozzle 120, or a convergent subsonic nozzle, is shown by the constriction in the pipe section. The nozzle of the arm conduit of Catherine Wheel can be a De Laval Nozzle, if the mass flow rate is sufficient. A very constricted section may be applied to the design if multi-stage expansion and cooling of the combined working fluid is considered as an important priority.

(20) It will be apparent to those skilled in the art that various modifications, combinations and variations can be made in the present invention without departing from the spirit or scope of the invention. Specific embodiments, features and elements described herein may be modified, and/or combined in any suitable manner. Thus, it is intended that the present invention cover the modifications, combinations and variations of this invention provided they come within the scope of the appended claims and their equivalents.