BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to the field of the generation of energy. More particularly, the invention relates to the generation of energy using heat, including energy generated using solar insulation directly or indirectly as a heat source.
2. Description of the Related Art
The generation of energy for purposes of power generation, including the direct conversion of energy to power such as through the use of an internal combustion engine to drive a shaft to rotate a tire for powering a vehicle, as well as the indirect use of using that rotating shaft to drive a generator for the generation of electricity has relied predominately on fossil fuel energy sources for nearly 100 years. Fuels such as oil, natural gas and coal have been readily available, relatively cheap, and easy to use for the generation of power. However, the side affects of nearly one hundred years of fossil fuel use for generating power has resulted in a diminishment of fossil fuel resources at the same time as world demand for energy and power is increasing, geopolitical instability as a result of real or perceived bias in favor of oil producing countries, and environmental impact ranging from ruination of land and other natural resources as coal is strip mined, to greenhouse gas emission based global warming. As a result, the true cost of fossil fuel based electrical generation is only now just being understood, and the immediate cost, based on the trade value of fossil fuel, is rapidly increasing as supply is outstripped by demand.
Therefore, there exists a need in the art for reliable, cost effective, energy and power generation using non-fossil fuel sources. One such source which has received considerable attention nearly three decades ago, and is again receiving considerable attention, is solar power generation.
One aspect of solar power generation is heat based solar power generation. This approach to power generation captures solar insulation to heat a working medium to generate electricity or provide energy for heating of homes and facilities. The methodology for solar generation of electricity typically includes a mechanism for heating a working fluid into a gas state, and expanding that heated gas state fluid through an expansion device which extracts energy from the fluid. For example, steam may be produced from solar heating water, and the steam is passed through a gas turbine or a steam turbine to cause the turbine to rotate about a shaft and enable the motion and momentum of the shaft to drive an electrical generator.
A common difficulty associated with the generation of steam for electrical generation using solar insulation is the inability to concentrate heat to generate steam in sufficient quantity at specific quality to effectively and economically generate electricity which can compete in price and reliability with fossil fuel based electrical generation.
SUMMARY OF THE INVENTION
The present invention provides a solar based generating system, alone or in conjunction with other solar generating systems and/or wind powered systems, geothermal powered systems and fossil fuel powered systems, wherein solar insulation is used to heat a working fluid to high temperatures and then transfer that heat to a generating mechanism, such as a gas turbine, a steam turbine or the like directly, or through a secondary exchange of energy in the form of heat between the working fluid and an additional fluid such as air, or water and steam which is useful for passing through such power generating devices.
In one aspect, a double walled tubular conveyance is provided, coupled to which are one or more solar insulation focusing devices. Fluid is passed through the annular tubular portion of the conveyance, thence through one or more of the focusing devices, and thence into the inner diameter of the conveyance device. Once the fluid is so heated by solar insulation, it is passed to a generation portion, wherein the energy is used to generate electricity.
In another aspect, the heated fluid is passed to a heat exchanger, and the heated fluid is caused to lose heat to a second fluid, which second fluid absorbs heat lost by the fluid. This second fluid is then converted to work. In one aspect, that work is the expansion of the gas through a gas turbine to cause the gas turbine to rotate a shaft and thereby ultimately drive a generator for the generation of electricity. In another aspect, the second fluid may be preheated before it exchanges heat with the heat exchanger. In still a further aspect, the second fluid may be used to drive a steam turbine to cause a shaft to ultimately drive a generator to generate electricity.
In yet another aspect, the heated fluid may be ported to a reservoir of hydrocarbons, such as oil shale, where the hydrocarbons cannot be immediately recovered without a secondary process, such as the introduction of heat to cause the hydrocarbons to exit the underlying matrix and be recoverable for use as a fuel. In this aspect, the heated water, in the form of steam, superheated steam or high pressure high temperature liquid water, are directed to a reservoir, such as a shale bed, where the liquid is circulated and returned to a generating facility. Typically, the liquid may be injected through a well bore which has been drilled to a subsurface formation, and a return bore is provided at a distance from the first, injection bore. The high temperature liquid is injected into the reservoir, and the high temperature liquid, and any hydrocarbon or other material released by the formation during injection of the high temperature liquid, are flowed to the surface through the return or second bore, where they may be separated for use as combustible fuel.
DESCRIPTION OF THE DRAWINGS
So that the manner in which the above recited features of the present invention can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.
FIG. 1 is a schematic perspective view of a dual walled conveyance useful for the present invention;
FIG. 2 is a sectional view of a prior art solar insulation capturing device useful for the present invention;
FIG. 3 is a schematic sectional view of the operation of the solar insulation capturing device of FIG. 2;
FIG. 4 is a schematic sectional view of the solar insulation capturing device of FIG. 2 coupled to the dual walled conveyance of FIG. 1;
FIG. 5 is a schematic sectional view of a plurality of the solar insulation capturing devices of FIG. 2 coupled to the dual walled conveyance of FIG. 1;
FIG. 6 is a schematic view of the solar insulation capturing device of FIG. 2 coupled to the dual walled conveyance of FIG. 1 positioned to receive solar insulation and convey the captured energy of solar insulation to a generating facility;
FIG. 7 is a schematic view of a generating facility coupled to the solar insulation capturing device of FIG. 2 coupled to the dual walled conveyance of Figure;
FIG. 8 is an additional schematic view of a generating facility coupled to the solar insulation capturing device of FIG. 2 coupled to the dual walled conveyance of FIG. 1;
FIG. 9 is a schematic vie of a solar insulation capturing device of FIG. 2 coupled to the dual walled conveyance of FIG. 1, wherein the captured solar insulation is used to release hydrocarbons from a trapped hydrocarbon reservoir; and
FIG. 10 is a schematic vie of the solar insulation capturing device of FIG. 2 coupled to the dual walled conveyance of FIG. 1, coupled with an additional solar facility for generation of electricity.
DESCRIPTION OF THE EMBODIMENTS
Reference is now made to FIG. 1 in which a dual walled conveyance forming a high-temperature energy transportation pipeline 20 is shown which comprises an outer tubing 22 and an inner tubing 24, having a gap therebetween forming a flow annulus 26. Within inner tubing 24 is provided a flow conduit 28. Both the outer tubing 22 and the inner tubing 24 may be constructed from materials such as carbon steel and others well known to one skilled in the art. Pipeline 20 enables the delivery of a fluid, or gas to a location, and passage of that fluid back to its origin through the pipeline 20. To accomplish this, and to minimize temperature change of the returning fluid, the flow annulus 26 is used to transport cooler fluids and the flow conduit 28 is used to transport hotter fluids. Such fluids include water/steam, air, helium, argon, and molten salts. To help increase the likelihood of a constant temperature differential between the flow volume 28 and the flow annulus 26 a high efficiency thermal insulator 32 surrounds and is contacted against the outer surface of the inner tubing 24 within flow annulus 26. The thermal insulator 32 may be made from materials such as low-density, high-purity silica at 99.8-percent amorphous fibers and made rigid by ceramic bonding and other methods that are known to one skilled in the art. In the preferred embodiment the pressure maintained in the outer flow annulus 26 is roughly equivalent to the pressure in the flow conduit 28 thereby circumventing the necessity of using higher pressure resistant materials for the inner tubing 24. Such pressure can be controlled by managing the flow rates of the fluids and gasses in conjunction with known information about their density/specific gravity at the range of temperatures they will exist at within the pipeline 20.
Referring now to FIG. 2, there is shown a solar insulation capturing device useful for practicing the inventions herein. In the specific device shown, a Karni collector 40, substantially as shown and described in U.S. Pat. No. 6,516,794, hereby incorporated by reference, is employed as the capturing device. Generally, the Karni collector includes a body 42, typically of a metal, having a front cover 44 through which extends an opening 46, with which is sealingly engaged a generally conically shaped window 48. This window 48 includes a front surface 50 which faces a source of concentrated solar insulation, and a back surface 52 against which fluid can be brought to bear. Fluid to be heated by solar insulation is flowed through an inlet 58 and into a solar receiving portion 60 formed between the window 48 and the body 42 and exits therefrom, after being heated by solar insolation, through exit 64. The operation and construction of a Karni collector is believed to be well know to one skilled in the art.
Referring now to FIG. 3, the mechanism for heating of the fluid in the Karni 40 collector is shown schematically. A focused beam 74 on solar radiation, typically formed by locating one or more mirrors to reflect and focus solar insolation, is directed at the window 48 of the collector 40. Fluid to be heated from the solar insulation is flowed into the collector as shown by arrows 70, enters the collector 40, contacts the window 48, and is heated wherein it is then flowed out of the collector 40 as shown by arrows 72. Thus, cooler fluid as shown by arrows 70 enters into the into the central solar receiving portion 60 adjacent to the window 48 and is heated by the focused beam of solar insulation 74 (as will be described further herein) and outputted as higher temperature fluid as shown by arrows 72 through exit 64 (FIG. 2).
Referring now to FIG. 4, a Karni style collector is configured to be directly coupled to a pipeline 20 in which cooler fluid is flowed from the flow annulus 26 to enter the central solar receiver 60, and the fluid, is heated to higher temperatures in the focused solar insulation (FIG. 2) which is directed to the receiver and is then flowed to the flow volume 28 as a heated fluid. Alternatively, a plurality of such collectors 40 as shown in FIG. 5 may be coupled to the pipeline 20 to receive fluid from the flow annulus 26 and after passing therethrough, flowed into flow volume 28. In one aspect, the fluid can be flowed in series such that the fluid is flowed from the outlet 64 of one Karni style collector to the inlet 58 of another, or in parallel, such that a plurality of Karni style collectors each receive fluid from the flow annulus of the pipeline 20, and each discharges the fluid to the flow volume 28 of the pipeline 20.
To operate, the pipeline 20 with the Karni collector 40 must be positioned in line with directed solar insolation. Referring now to FIG. 6, a solar tower 80 is provided to support pipeline 20 such that plurality of Karni collectors 40 (only one shown) are supported adjacent to the terminus 82 of the pipeline 20. Pipeline 20 is supported in a substantially vertical position. The pipeline 20 is connected to a power plant 100, such that a working fluid is pumped from the power plant 100 through flow annulus 26, and thence through the Karni collector(s) 40, and thence back to the power plant 100 through flow conduit 28. Thus, the heat from solar insulation input into the fluid passing through the Karni collector 40 is captured by that fluid, and thence flowed to power plant 100 to be used to produce electricity in the power plant 100. Such power generation, including electrical power generation, is known to those skilled in the art. The heat from solar insulation may be used as the sole heat source to turn a steam or gas turbine, or as a supplemental boost heat source in combination with other energy sources, including fossil fuel sources such as coal, oil or gas. The solar insulation is concentrated directly into the Karni collectors 40 by a plurality of ground-based reflectors such as heliostats 102 and/or curved mirrors 104 which are positioned to reflect light from the sun 110 and direct that light in a concentrated beam in the direction of the Karni collectors 40. Although only one heliostat 102 and one curved mirror 104 are shown, it is specifically contemplated that a plurality of such reflectors may be provided, and a plurality of such reflectors are configured to direct a concentrated beam of reflected solar insulation at a single Karni collector 40. These reflectors 102, 104 may be controlled to track the sun such that their focused reflection falls upon the window of a Karni collector 40.
Referring now to FIG. 7, one configuration of the power plant 100 of FIG. 6 is shown in schematic. As discussed with respect to FIG. 6, pipeline 40 is supported by solar tower 80, such that solar insulation is reflected off a plurality of reflectors 102, directly into a plurality of Karni collectors 40 (in FIG. 5). Energy from the focused insulation beam is transferred to the heat transporting fluid and is flowed through flow volume 28. In one aspect the working fluid may be steam/or superheated pressurized water, i.e. water remaining liquid above the one atmospheric boiling point of 212 degrees farenheit. Super-heated water at 270° C. under a pressure of, by way of example, 100 bars is introduced into the Karni collectors 40 and converted into super-heated steam at a temperature between 1000° C. and 1500° C. The steam travels down the flow conduit 28 to the power plant 100 where it is directed into a stream turbine 110 that drives an electricity generator 112 to produce electricity 114. During hours when sunlight is not available (night or cloudy) steam is provided via a boiler 116 heated by conventional energy source 118 such as natural gas. The expended steam exits the turbine 110 after the first stage 120 still as pressurized steam or after the second stage 122 as steam at low pressure (215° C. and 0.01 bar). In the latter case the steam is directed to a Steam Condenser 58 that condensates the steam back into water while increasing the pressure back up to pressures of 100 bar and temperatures of 200° C. The Steam Condenser 124 is cooled by a Cooling Tower 126. The steam exiting the Steam Condenser 124 is then mixed with the steam that exited the Steam Turbine 110 at the first stage 120. The water is then heated in a Pre-Heater 130 to 270° C. while maintaining a pressure of 100 bar and returned to the pipeline 20.
Referring now to FIG. 8, an alternative configuration of power plant 100 is shown in schematic. Again, as in the configuration shown in FIG. 7, the pipeline 20 is structured into a solar tower 80 (FIG. 6) in a manner described in FIG. 6. Solar light is reflected off a plurality of reflecting surfaces 102, 104 (FIG. 6) directly into a plurality of Karni collectors 40 as illustrated in FIG. 5. The energy from the focused light beam is transferred to the heat transporting fluid which is then flowed in the flow conduit 28 to the power plant 100. In this embodiment the fluid is steam/water. Super-heated water at 270° C. under a pressure of, by way of example, 100 bars is introduced into the Karni central solar receivers 40 and converted into super-heated steam at a temperature between 1000° C. and 1500° C. The steam travels down the flow conduit 28 to the power plant 34 where it is directed into a heat exchange unit 200. Compressed air 202 at 500° C. from a compressor 204 is heated in the heat exchange unit to temperatures between 1000° C. and 1500° C. This super heated air is then fed into a gas turbine 206 connected to an electricity generator 208 that produces an electrical output 210. The temperature of the super heated air is supplemented by means of air heated in a combustion chamber 212 by means of a non-solar fuel 214 such as natural gas. The cooled steam from the heat exchange unit 200 is passed to a steam condenser 216 that is cooled by cooling towers 218. The water from the steam condenser 216 is reheated in a pre-heater 220 that is heated by the exhaust gases from the gas turbine 206. The water exits the pre-heater 220 at a temperature between 150° C. and 400° C. at a pressure, by way of example, of 100 bar. The super-heated water then re-enters the flow annulus 26 of the pipeline 20. It is specifically contemplated that a steam turbine (FIG. 7) can be added to the cycle, driven by the steam exiting the heat exchange unit 200 for a combined cycle high efficiency turbine.
The heat energy captured from solar insulation by the pipeline 20 and collector 40 combination may be used for other than direct electrical energy production. Referring now to FIG. 9, one such use is shown and described, wherein the pipeline 20 is configured to inject hot working fluid into a subsurface formation 300, into which a well has been drilled and cased, such that a wellbore 304 extends from the formation 300 to the surface. Pipeline 20 and collector 40 are configured to provide heat energy to the subsurface formation containing fossil fuels entrained or trapped in a formation 300, whereby heat will release the fossil fuel from the formation. In this aspect, pipeline 20 and Karni collectors 40 are structured into a solar tower 80 as shown in FIG. 6. Solar light is reflected off a plurality of reflecting surfaces 102 and/or 104 (FIG. 6) directly into a plurality of Karni collectors 40 as illustrated in FIG. 5. The energy from the focused solar insolation beam is transferred to the heat transporting or working fluid flowing in the flow conduit 28. In this embodiment the fluid is steam/water. Super-heated water at 270° C. under a pressure of, by way of example, 100 bars is introduced into the Karni collectors 40 and converted into super-heated steam at a temperature between 1000° C. and 1500° C. The steam travels down the flow conduit 28 and is released into a mineral-rich geological formation 300 such as shale. The extracted materials 302 are taken up the wellbore 304 and directed to a processing plant 320. The processing plant 320 also prepares the super-heated water for the pipeline 20 in a similar manner described hereinabove (FIG. 6).
The pipeline 20 and Karni collector 40 may also be used to provide supplemental heat to a power generating facility. With reference to FIG. 10, the pipeline 20 is structured into a solar tower 80 in a manner described in FIG. 6 hereinabove. Solar light is reflected off a plurality of reflecting surfaces 102, 104 directly into a plurality of Karni collectors 40 as illustrated in FIG. 5. The energy from the focused light beam is transferred to the heat transporting or working fluid flowing in the flow conduit 28 of the pipeline 20. In this embodiment the fluid is steam/water. Super-heated water at 270° C. under a pressure of, by way of example, 100 bars is introduced into the Karni collector 40 and converted into super-heated steam at a temperature between 1000° C. and 1500. The steam travels down the flow conduit 40 where it is directed into a heat exchange unit 400. The heat exchange unit 400 is conjoined with piping from an energy producing source such as a Solar Energy Generating Station (SEGS) 402 in such a manner as to increase the temperature of the heat transfer liquid, for instance oil, from the SEGS 402 from a current maximum in the range of 450° C. to above 1000° C. The temperature boosted energy transfer fluid is directed from the heat exchange unit 400 to a power block 404. The increase in temperature of the energy transfer fluid will enable higher efficiency production of electricity. The cooled fluid from the solar tower 80 exits the heat exchange unit and returns through the flow annulus 26 of the pipeline 20 back to the Karni collectors 40. Thus, the solar insulation captured in the working fluid may be used to supplement or boost the heat energy used to generate electricity. Although the supplement and/or boosting feature is described in terms of a SEGS facility, the pipeline 20 may be used in combination with other generating facilities, including facilities solely based on fossil fuel, to boost or supplement the heat energy used to generate electricity therewith.
While the foregoing is directed to embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.
Patent Application
20070221208
