US20080127648A1

US20080127648A1 - Energy-conversion apparatus and process

Info

Publication number: US20080127648A1
Application number: US11/930,616
Authority: US
Inventors: Craig Curtis Corcoran
Original assignee: Individual
Current assignee: Individual
Priority date: 2006-12-05
Filing date: 2007-10-31
Publication date: 2008-06-05
Also published as: WO2008070366A2; WO2008070366A3

Abstract

One embodiment of an energy-conversion apparatus includes a first container to contain working fluid under pressure, a first heat-transfer component in the first container, a second container to contain fluid under pressure, a second heat-transfer component in the second container, and an energy converter coupled to the first and second containers that performs work in response to a flow of fluid through the energy converter, wherein the flow is motivated by varying a pressure within the first container or within second container (or both) caused by the first heat-transfer component or the second heat-transfer component, respectively, without a need for heat conduction through an exterior surface of either container. An energy-conversion method includes, from within one or both of first or second containers, varying an internal temperature to cause a resultant pressure differential that motivates the fluid to flow between the first and second containers, and performing work as fluid flows through the energy converter between the containers.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This Application claims the benefit of U.S. Provisional Application No. 60/868,709, filed on Dec. 5, 2006.

INTRODUCTION

Non-renewable sources of energy generation, such as oil and coal, risk depletion. Other sources of energy, such as hydroelectric dams and nuclear facilities, present actual or potential environmental consequences. There is a continuing need to garner usable energy from renewable, environmentally sensitive sources that utilize, for example, solar radiation and geothermal technologies.

SUMMARY

The present invention is defined by the claims below. But in summary fashion, embodiments of the invention provide a way to convert renewable, environmentally sensitive sources of energy, such as solar radiation and geothermal technologies, as well as non-renewable sources of energy, such as natural gas, into more readily usable forms of energy, such as electricity. Pressure differentials between containers are used to motivate exchanges of a working fluid between the containers, which, in turn, are used to stimulate an energy converter and perform work. Work includes any kinetic response to a flow of working fluid, and also includes generating electricity. Heating and cooling of the working fluid takes place from within the containers rather than requiring heat conduction through the container shells, thus reducing parasitic heat losses and, therefore, enhances efficiencies.
In a first aspect, an energy-conversion apparatus includes a container to contain working fluid under pressure, a heat-transfer component in the first container; another container to contain working fluid under pressure; and an energy converter coupled to the containers that performs work in response to a flow of working fluid through the energy converter. The flow is motivated by varying a pressure within the first container caused by the first heat-transfer component.
In a second illustrative aspect, an energy-conversion apparatus includes a first container to contain working fluid under pressure, a first heat-transfer component in the first container that can manipulate an internal temperature of the first container (first internal temperature) from within the first container, a second container to contain working fluid under pressure, a second heat-transfer component in the second container that can manipulate an internal temperature of the second container (second internal temperature) from within the second container, and an energy converter coupled to the first and second containers that performs work in response to a flow of working fluid between the containers.
In a third illustrative aspect, an energy-conversion apparatus includes a first container of working fluid under pressure, a first heat-transfer component in the first container and that can manipulate an internal temperature within the first container without a need for heat conduction through an exterior surface of the first container, a second container of working fluid under pressure coupled to the first container, a second heat-transfer component in the second container that can manipulate an internal temperature within the second container without a need for heat conduction through an exterior surface of the second container; and an energy converter coupled to the containers and that can perform work in response to a flow of the working fluid between the containers.
In a fourth illustrative aspect, an energy-converting apparatus includes a first containment means for containing a first supply of working fluid under pressure, a first heat-varying means in the first containment means for changing a temperature within the first containment means, a second containment means for containing a second supply of working fluid under pressure, a second heat-varying means in the second containment means for changing a temperature within the second containment means, and a means for converting energy in response to a flow of working fluid between the first and second containment means, and vice versa, urged by a difference in pressure between the containments, which is induced by utilizing at least one of the first or second heating means to change the temperature within at least one of the first or second containments.
In a fifth illustrative aspect, an energy-conversion apparatus includes a first container to contain working fluid under pressure, a first inlet port that allows heat-transfer fluid to be introduced into an interior of the first container, a second container to contain working fluid under pressure, and an energy converter coupled to the first and second containers that performs work in response to a flow of working fluid through the energy converter. The flow is motivated by internally varying a pressure within the first container caused by direct heat transfer between the heat-transfer fluid and the working fluid.
In a sixth illustrative aspect, an energy-conversion apparatus includes: a first container of working fluid under pressure; a second container of working fluid under pressure coupled to the first container; a first heat-transfer component in the first container that, without a need for heat conduction through an exterior surface of the first container, can perform one or more of (1) internally increase a temperature within the first container above a temperature within the second container, and/or (2) internally decrease a temperature within the first container below a temperature within the second container; and an energy converter coupled to the first container and to the second container and adapted to perform work in response to a force exerted upon it. The force can be created as a result of a change in pressure in at least the first container caused by an internal manipulation of an internal temperature within at least the first container.
In a seventh illustrative aspect, an energy-conversion apparatus includes a first container to contain working fluid under pressure that has an inlet port, a second container to contain working fluid under pressure, an energy converter coupled to the containers that performs work in response to a flow of working fluid through the energy converter. The flow is motivated by internally varying a pressure within the first container caused by varying a temperature of the working fluid in at least the first container.
In an eighth illustrative aspect, a method for converting energy by utilizing a system comprising first and second containers to contain working fluid under pressure coupled to an energy converter is provided. One embodiment of the method includes from within one or both of the first and second containers, varying an internal pressure; and performing work as the energy converter is stimulated in response to a flow of working fluid motivated to pass through the energy converter by the varying internal pressure. The varying of the internal pressure includes effecting a temperature change from within the first container, thereby causing a resultant change in pressure.
In a ninth illustrative aspect, a method for converting energy includes, from within a first or second container, varying an internal temperature to cause a resultant pressure differential that motivates working fluid to flow between the containers, and performing work as working fluid flows through the energy converter between the containers in response to the pressure differential.
In a tenth illustrative aspect, a method for converting energy as working fluid flows between a first container that contains working fluid under pressure and a second container that contains working fluid under pressure includes stimulating an energy converter by inducing a fluid-exchange cycle through the energy converter by varying the pressure of at least one of the containers relative to the other by internally varying the temperature of the working fluid of at least one of the containers.
In an eleventh illustrative aspect, a method for converting energy includes providing a first a container to contain working fluid under pressure (the first container substantially surrounding a first heat-transfer component that can internally change an internal temperature within the first container), providing a second container to contain working fluid under pressure (it substantially surrounding a second heat-transfer component that can internally change an internal temperature within the second container), providing an energy converter coupled to the first container and to the second container, stimulating the energy converter with a flow of working fluid from the first container to the second container by internally varying a pressure within the first or second container by varying a temperature within the first or second container so that a first pressure differential between the two containers is sufficiently high that it motivates the flow until the differential pressure between the two containers reaches a desired low pressure differential, and increasing the desired low pressure differential to a second sufficiently high pressure differential so as to motivate a flow of the working fluid from the second container to the first container by varying a temperature within the first or second containers.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

Illustrative embodiments of the present invention are described in detail below with reference to the attached drawing figures. In the figures, hatching generally represents heat-transfer fluid. The drawings are incorporated by reference herein, and wherein:

FIGS. 1A-1B depict several phase diagrams of an embodiment of the present invention;

FIGS. 2A-2D depict a more detailed illustration of various stages that an embodiment of the present invention passes through to convert other forms of energy into electricity;

FIGS. 3A-3D are additional simplified diagrams depicting high-level aspects of the invention;

FIGS. 4A-4D are additional simplified diagrams depicting high-level aspects of the invention;

FIG. 5 depicts an illustrative method for practicing an embodiment of the present invention;

FIG. 6 depicts still a more detailed illustrative operating environment suitable for practicing an embodiment of the present invention;

FIG. 7 depicts another illustrative system utilizing direct heat-transfer techniques according to an embodiment of the present invention; and

FIG. 8 depicts an illustrative system utilizing a piston apparatus according to an embodiment of the present invention.

DETAILED DESCRIPTION

As briefly mentioned, embodiments of the present invention provide a way to convert renewable, environmentally sensitive sources of energy, such as solar radiation and geothermal technologies, as well as non-renewable sources of energy, such as natural gas, into more readily usable forms of energy, such as electricity. One or more heat transfer components are situated within the interior of two or more containers and are utilized to vary a temperature of at least a portion of an enclosed working medium to develop a pressure differential between portions of the medium. The pressure differential can be used to motivate a flow of the working medium that can, in turn, be used to motivate a motive power source/perform work/generate energy (such terms are used substantially interchangeably herein).
Turning now to FIGS. 1A and 1B, several phase or state diagrams are depicted that illustrate various aspects of an embodiment of the present invention. Turning first to FIG. 1A, and more specifically to the beginning of Phase I illustrated generally by reference numeral 110, a first container 112 is adapted to contain a quantity of working fluid 114 under pressure. First container 112 and second container 116 are depicted illustratively as spherical in shape, of equivalent volume, and as separate structures. However, such depiction should not be construed as limitations of the present invention. To the contrary, first container 112, as well as second container 116 may take on a variety of forms. For example, the shapes may be round, cylindrical, or other manmade design, or even take the form of natural caverns or caves to the extent they can be adapted to contain fluid under pressure. It is not necessary that the containers be of equivalent volume and may comprise portions of a single overall structure.
Relative quantities of working fluid in the containers are generally represented by dots (e.g., FIG. 1 through FIG. 4). These dots are provided to illustratively help understand various embodiments of the present invention, and should not be confused with indicating either an absolute mass or a relative pressure. Moreover, differences are exaggerated for illustrative purposes to indicate relative quantity differences. Indeed, under certain conditions, one container may contain a greater mass of working fluid than the other container, but because of temperature differences, they may be at the same pressure, or it may also be the case that the container with the relatively less working fluid is actually at a greater pressure than the other container. Not all drawings depict working fluid as dots (e.g., FIG. 6) so as to not obscure certain aspects of some embodiments of the present invention. Moreover, some drawings (e.g., FIG. 7 and FIG. 8) use dots to depict heat-transfer fluid rather than working fluid, which is identified, but not visible by markings.
Second container 116 contains an amount of working fluid 118 under pressure. As will be explained in greater detail below, the working fluid of each container will flow between the containers, but separate referenced numerals are provided so as to facilitate an easier explanation of an embodiment of the present invention. Working fluid 114 and working fluid 118 may be a gas, vapor, mixture of gases, and the like. As used herein, the term “fluid” used in connection with “working fluid” is not necessarily limited to mean a gas alone, but may be a combination of gas and liquid in certain situations.
Two sources of heat-transfer fluid are shown. A first source of heat-transfer fluid is referenced by numeral 120, and is relatively hotter than a second source of heat transfer fluid 122, which is relatively cooler than hotter heat-transfer fluid 120. Heat-transfer fluid 120 and heat-transfer fluid 122 may be a liquid, gas, vapor, and the like. As used herein, the term “fluid” used in connection with “heat-transfer fluid” is not necessarily limited to mean a gas alone or a liquid alone, but may be a combination of gas and liquid in certain situations. For ease of reading purposes, “heat-transfer fluid” will be abbreviated as “HTF.” HTF should not be construed as hot or cold per se. Rather, as the name suggests, it is a fluid that is used to communicate or transfer a level of heat. This can refer to a process of emitting or introducing heat or to a process of absorbing or withdrawing heat.
Several instruments, valves, gauges, control mechanisms etc., are not shown in the phase diagrams of FIGS. 1A and 1B because these diagrams are meant to provide a high-level overview of the way that an embodiment of the present invention functions. More detail surrounding these various omitted items will be provided below. But an illustrative valve 124 is shown coupled to an energy converter 126, which generates electricity itself or is coupled to a generator 128. In other embodiments it may be a piston. In Phase I, valve 124 depicts a closed position. That is, the working fluid contained in each of the containers is not allowed to flow between the containers. Conduit 130 provides a flow path through which either working fluid 114 could flow, if motivated, from first container 112 through valve 124, if open, energy converter 126, and into second container 116 or, alternatively, working fluid 118 could flow, if motivated, from second container 116 through energy converter 126 and valve 124, if open, and into first container 112. Also simplified in the diagrams of FIGS. 1A and 1B are the connections to a turbine or other energy converter 126. Energy converter 126 may be a turbine, but may also be other forms of energy-generation devices that can generate energy or perform work in response to a flow of fluid between the two containers (for example, a piston). In some embodiments, the energy converter is not a piston. An example of the simplification depicted in diagram 110 is that a single inlet and egress is shown regarding energy converter 126. But it is contemplated within the illustration that subchannels may actually exist within conduit 130. This would be the case if it is desired that energy converter 126 rotate in the same direction during each fluid-exchange cycle. In such a case, a specialized turbine, such as a warm-drive turbine, could be employed that utilizes a single flow path, or dual flow paths could be provided so that working fluid can flow through a first path and cause rotation in a first direction, but flow in a second path during a reverse cycle and still cause energy converter 126 to rotate in the same direction that it did as working fluid flowed through the first path.
Structure 132 indicates that hotter HTF 120 is introduced within first container 112 to warm working fluid 114. Structure 132 is depicted in an illustrative sense to indicate that working fluid 114 is exposed, directly or indirectly, to hotter HTF 120 from a disposition within the interior of first container 112. Structure 132 may take on a variety of forms, including conduit, or coils of conduit, made out of a heat-conducting material, such as copper or aluminum. In other embodiments, structure 132 may take the form of an inner wall of first container 112. In still other embodiments, the hotter HTF is allowed to come into direct contact with the working fluid and to transfer heat without being contained in a conduit or other component via the introduction of the hotter HTF through a port or other inlet in the wall of container. Although shown separately, another structure 134 can be used to allow working fluid 114 to be exposed to the effects of cooler HTF 122. In some embodiments, structures 132 and 134 are one and the same. They are shown separately merely to help facilitate an easier understanding of an embodiment of the present invention.
Similarly, structure 136 can be used to expose working fluid 118 to the effects of hotter HTF 120 in second container 116. And structure 138 can be used to introduce cooler HTF 122 into an interior of second container 116 so that it can withdraw heat from working fluid 118.
Four legends are shown in diagram 110: a first pressure legend 140, a first temperature legend 142, a second pressure legend 144, and a second temperature legend 146. These are referred to as legends because they are not necessarily actually gauges. This is why no lines are shown connecting the legends to the containers. Although in some embodiments, the respective containers are associated with gauges, such as pressure gauges and temperature gauges, the legends are shown to help the reader understand the happenings during the illustrative phases of an embodiment of the present invention. For example, first pressure legend 140 merely indicates a relatively moderate starting pressure associated with the interior of first container 112. Similarly, first temperature legend 142 indicates that a relatively low temperature is initially associated with working fluid 114 at the beginning of Phase I. Second pressure legend 144 indicates that a relatively moderate starting pressure is also associated with working fluid 118, and second temperature legend 146 indicates that a relatively high temperature is initially associated with working fluid 118 at the beginning of Phase I, 110. The various indications are not intended to represent actual quantified pressures and temperatures, but are merely provided to indicate relative variances as the various phases are progressed through.
At the beginning of Phase I, hotter HTF 120 begins to circulate through structure 132 in such a way that it introduces heat into working fluid 114. At the same time, cooler HTF 122 is introduced via structure 138 to the interior of second container 116 in such a way that it withdraws heat from working fluid 118. An explanation in greater detail will be provided below as to how hotter HTF 120 attains its heat and how cooler HTF 122 attains its relative coolness. But summarily, in one embodiment, a conglomeration of reflecting devices, such as parabolic mirrors, can be used to concentrate and direct sunlight to one or more reservoirs that contain a portion of hotter HTF 120 so that it is heated. This process has been used to substantially heat fluids, such as oil or oil related substances. In one embodiment, geothermal processes are utilized to cool HTF 122.
Arrow 148 reflects a transition to an ending stage associated with Phase I and referenced generally by the numeral 150. At the end of Phase I, the pressure inside first container 112 a is higher than what it was at the beginning of Phase I. This relatively higher pressure is indicated by first pressure legend 140 a. The relatively higher pressure was caused by virtue of introducing heat into working fluid 114 a by way of hotter HTF 120 a. This relative increase in temperature is represented by first temperature legend 142 a, depicting a relatively higher temperature than that of the beginning of Phase I. The pressure in second container 116 a has dropped below what it was at the beginning of Phase I, indicated by second pressure legend 144 a, and a temperature of working fluid 118 a is relatively lower than it was at the beginning of Phase I, which is indicated by second temperature legend 146 a. The relatively lower pressure and temperature was caused by virtue of withdrawing heat from working fluid 118 a by way of cooler HTF 122 a. Valve 124 a is still closed at the end of Phase I. At this point, working fluid has not been allowed to be exchanged between the two containers.
Arrow 152 reflects a transition from the end of Phase I to the beginning of Phase II, which is referenced generally by the numeral 154. At the beginning of Phase II, valve 124 b (which is the same as valve 124 a and valve 124, but is given a unique reference numeral to facilitate explanation) is depicted in an open position, thereby allowing working fluid 114 b to flow from first container 112 b into second container 116 b. This flow is indicated by arrow 155 b. This flow is motivated by a relatively higher pressure within first container 112 b at the beginning of Phase II, as indicated by first pressure legend 140 b, than the relatively lower pressure within second container 116 b, as indicated by second pressure legend 144 b. As working fluid 114 b flows through energy converter 126 b it causes energy converter 126 b to rotate and thereby generate useable energy. Energy converter 126 b could be a generator and generate electricity itself or could be another type of motive power device, such as a turbine, and be coupled to generator 128 b, or could supply motive power to any other applicable device to perform any other suitable type of work. Hotter HTF 120 b can be allowed to continue to be circulated within an interior of first container 112 b during Phase II so as to attempt to add additional heat energy to the working fluid 114 b within first container 112 b to prolong or accentuate a relative pressure differential between the two containers during the fluid exchange from first container 112 b to second container 116 b. Similarly, cooler HTF 122 b can be continued to be allowed to be exposed to working fluid 118 b during Phase II. The fluid-exchange cycle is allowed to continue until a desired minimum pressure differential between the two containers is reached. Transition arrow 156 indicates a transition from the beginning of Phase II to the ending of Phase II, which is referenced generally by the numeral 158. At the end of Phase II, the pressures in each of the containers are relatively near each other, which are indicated by first pressure legend 140 c and second pressure legend 144 c.
Turning now to FIG. 1B, the next state that is illustrated is the beginning of Phase III, which is referenced generally by the numeral 160. As shown, valve 124 d is in a closed position, prohibiting any working fluid to be exchanged between the two containers. With valve 124 d closed, hotter HTF 120 d is allowed to be circulated in such a way that it effects or translates to working fluid 118 d in second container 116 d. Similarly, cooler HTF 122 d is circulated within first container 112 d so that it cools the remaining working fluid 114 d in first container 112 d.
It is worth noting that relative variances can be attributed to a part of the success of the present invention. That is, absolute temperatures and pressures are not as relevant as relative temperatures and pressures; namely, temperatures and pressures of a given state relative to temperatures and pressures of a prior state; or the pressure within a given container relative to the pressure within another container. Recall that at the end of Phase II, a substantially equilibrium pressure state had been reached wherein working fluid no longer passed from the first container to the second container. With valve 124 d closed in Phase III, the pressure in second container 116 d is allowed to increase relative to the pressure at the end of Phase II, and the pressure associated with first container 112 d is allowed to decrease relative to the pressure at the end of Phase II. Such a state is reflected by numeral 162, denoting an ending of Phase III.
Transition arrow 164 depicts a transition from the beginning of Phase III to the ending of Phase III. At the end of Phase III, the pressure and temperature in first container 112 e is relatively lower than what it was at the beginning of Phase III. This state is indicated by first pressure legend 140 e and first temperature legend 142 e. Valve 124 e remains closed. By virtue of the continued circulation of hotter HTF 120 e, the pressure and temperature of working fluid 118 e in second container 116 e are both relatively higher than they were at the beginning of Phase III, or the end of Phase II. The relatively higher pressure is indicated by second pressure legend 144 e, and a relatively higher temperature is indicated by second temperature legend 146 e.
At the end of Phase III, a pressure differential exists between the working fluid in first container 112 e and the working fluid in second container 116 e. Whenever a sufficient pressure differential exists, the energy converter 126 e and generator 128 e can be stimulated to generate electrical energy. Thus, arrow 166 indicates a transition to the beginning of Phase IV, which is referenced generally by the numeral 167. At the beginning of Phase IV, valve 124 f is opened up so that working fluid 118 f is allowed to flow from second container 116 f through energy converter 126 f into first container 112 f. This flow is illustrated by arrow 155 f. In one embodiment, hotter HTF is allowed to continue to circulate within an interior of second container 116 f while cooler HTF 122 f is allowed to circulate within an interior of first container 112 f. The fluid-exchange cycle is allowed to continue until the two pressures between the two tanks become sufficiently relatively close to each other, which signals the ending of Phase IV.
Arrow 170 reflects a transition from the beginning of Phase IV to the ending of Phase IV, which is referenced generally by the numeral 172. The ending of Phase IV is substantially similar to the beginning of Phase I except that valve 124 g is shown open. Valve 124 g is shown open to allow any motivated fluid remaining in second container 116 g to flow into first container 112 g. At a desired point, valve 124 g is closed, which state is reflected as the beginning of Phase I, 110.
The cycle can then be repeated an indefinite number of times. FIGS. 1A and 1B have provided a high-level overview of an illustrative operating environment of the present invention. Renewable energy sources, such as heat from the sun or coolness of the earth, or other sources of heating and cooling, such as natural gas or heat pump technologies, are used in such a way as to alternatively heat and cool a working fluid between two containers from the inside of the containers so that relative pressure differentials between the two containers can be used to motivate exchanges of fluid between the two containers that stimulates a motive power source, such as a turbine to generate useable electricity or perform other work. Resulting electricity can be used immediately or stored at a later time using a technology such as batteries, water lifting, a capacitive bank, compressing gas, or the like.
Turning now to FIG. 2A, another operating environment suitable for practicing an embodiment of the present invention is provided and referenced generally by the numeral 200. As shown, this embodiment depicts in greater detail various valves, monitoring equipment, and other devices that can be employed to convert energy such as solar energy into useable electricity. A parabolic mirror 210 directs sunlight to a receiver tube 212 that contains hotter HTF 214. Although not shown, a series of parabolic mirrors could be used to concentrate additional sunlight at receiver tube 212 so as to provide additional heat energy to hotter HTF 214. A reservoir 216 may be used to store an amount of hotter HTF 214. A pump 218 can be used to circulate hotter HTF 214 through an interior of a first container 220. During circulation, valves 222 and 224 are positioned in such a way that fluid can circulate through the various conduit sections, as illustrated. As hotter HTF 214 circulates through an interior of first container 220, it warms working fluid 226. Although an inner conduit 228 is shown as disposed within first container 220, in some embodiments it may form an inner wall of first container 220.
Another reservoir 230 can be used to contain cooler HTF 232. In one embodiment, reservoir 230 is disposed sufficiently within the earth (ground or water) so that the earth acts as a heat path to maintain cooler HTF 232 at a substantially constant, relatively cooler temperature. In another embodiment, reservoir 230 is not so much a reservoir as it is a series of conduit tubing that runs deep underground or underwater so as to allow heat to be leaked off into the earth, which again helps maintain a relatively cooler temperature of cooler HTF 232.
A pump 234 motivates cooler HTF 232 to circulate within an interior of second container 236 to withdraw heat from a second supply of working fluid 238. Pump 234 motivates fluid flow when valves 240 and 242 are positioned in such a way as to direct cooler HTF 232 through the conduit shown and into the interior of second container 236 as represented by structure 244, which is shown as being within second container 236. Heat transfer fins 246 and 248 can be used to further facilitate the transfer of heat into or out of the respective working medians. During this stage, a main valve 250 is closed to prevent working fluids 226 and 238 from flowing between the containers.
A computerized controller 252 is coupled to a variety of sensing devices that are used to receive data that is used to control the various pumps and valves to help optimize an efficiency associated with the various phases, stages, and fluid-exchange cycles. For example, controller 252 is coupled to a first pressure gauge 254 associated with first container 220 as well as a first temperature gauge 256 also associated with first container 220. Similarly, controller 252 is coupled to a second pressure gauge 258 associated with second container 236, as well as a second temperature gauge 260 also associated with second container 236. These respective temperature and pressure gauges can be used to monitor the respective temperatures and pressures associated with the respective working fluids of the containers. Similarly, the attributes of the heat-transfer fluids can also be monitored. For example, a first HTF temperature gauge 262 and a second HTF temperature gauge 264 monitors temperature associated with the HTFs in this embodiment.
Armed with input from one or more of these devices, controller 252 can control the various pumps and valves and regulators. For example, controller 252 is coupled to a first HTF pressure regulator 266 as well as to a second HTF pressure regulator 268. The HTF pressure regulators can regulate the pressure associated with the heat-transfer fluids to reduce the difference in pressure between the interiors of the heat-transfer conduits and the interiors of the containers in order to reduce the risk that the conduits may collapse or erupt (this may also enhance overall energy efficiency as the required strength and, therefore, thickness of the conduit walls may be reduced). Moreover, controller 252 is coupled to the various pumps and valves so as to allow the circulation of the HTF when desired.
When fluid is allowed to be exchanged between the two containers, a turbine 270 is used to produce motive power for a generator 272 which, in turn, generates electrical energy. Controller 252 may also be coupled to a working-medium pressure regulator 274 to regulate pressure between the two containers.
This state in FIG. 2A is allowed to persist until a desired pressure differential develops between the two containers. When a desired pressure differential exists between the two containers, main valve 250 can be opened, as shown in FIG. 2B, to allow an exchange of working medium between the two containers through pathway 276 in FIG. 2B.
During the state of FIG. 2B, electricity is generated as turbine 270 and generator 272 stimulated by the flow of fluid between the containers. This flow can be allowed to continue until the pressure differential between the two containers is reduced to a threshold level. This threshold level may occur by virtue of controller 252 imposing a restriction, or may occur by virtue of the fluid flowing from second container 236 into first container 220. Regarding the masses of working fluid illustratively depicted in FIG. 2B (as well as FIG. 2D), note should be taken that those figures depict a transitionary state. When as much working fluid flows from first container 220 into second container 236 as is desired, controller 252 can close main valve 250, which is represented by FIG. 2C.
In FIG. 2C, main valve 250 is shown to be closed. Having just reached a near equilibrium state, the two containers are now allowed to again develop a pressure differential with respect to each other. This occurs by warming the working fluid 238 in second container 236 while cooling working fluid 226 in first container 220.
Working fluid 238 is heated by receiving the effects of heat transfer from the circulation of hotter HTF 214 being circulated within an interior of second container 236. In one embodiment, controller 252 stimulates pump 234 to motivate a circulation of hotter HTF 214 after having positioned valves 222 and 240.
With continuing reference to FIG. 2C, controller 252 can also control pump 218 and valves 224 and 242 to cause a circulation of cooler HTF 232 within an interior of first container 220 so that its cooling effects are translated to working fluid 226 in first container 220.
In this embodiment, first and second containers 220 and 236 are provided first and second insulations 278 and 280, respectively, to inhibit the effects of ambient temperature from being translated to or from the working fluids 226 and 238 within the containers. The working fluids 226 and 238 are warmed and cooled from the inside of the respective containers, not from the outside (aside from parasitic heat transfers to or from the ambient).
During this time, controller 252 can monitor the temperatures and pressures of both working fluids as well as both heat-transfer fluids as previously described.
The warmer the working medium within second container 236 gets, the greater the pressure is developed. Similarly, the cooler the working fluid 226 becomes within first container 220, the lower the pressure becomes. This creates a relative pressure differential between the two containers that can be used to motivate an exchange of working fluid from second container 236 back to first container 220. This situation is represented in FIG. 2D.
Turning now to FIG. 2D, main valve 250 is shown to be open, and pathway 276 is shown to include a quantity of working fluid which represents a flow of working fluid 238 from second container 236 into first container 220. As the working fluid flows from a first container to a second container, turbine 270 is stimulated, which, in turn, stimulates a generator 272 that generates electricity in one embodiment. Controller 252 monitors the pressures and temperatures associated with the working fluid of each container as well as the temperature and pressures associated with each of the heat-transfer fluids in one embodiment. This fluid-exchange cycle is allowed to continue for as long as there is a sufficient pressure differential between second container 236 and first container 220 to motivate working fluid 238 to flow into first container 220. At the end of this cycle, main valve 250 can be closed and the state of FIG. 2A is reached, and the process can start all over again.
Turning now to FIG. 3A, another simplified view of a high-level overview of the present invention is shown. In this embodiment, warmer HTF 312 is circulated by heat-conducting structure 314 in an interior of first container 316 to warm working fluid 319. A layer of insulation 318 is shown to reduce the effects of ambient temperature on working medium 319.
A supply of cooler HTF 320 is circulated by way of a heat-conducting structure 322 in an interior of second container 324 to cool a second supply of working medium 326 inside second container 324. Various valves, pumps, controllers, etc., are not shown in this view so as not to obscure explanation of these high-level aspects of the invention. During a fluid exchange cycle, an amount of working fluid 319 flows into an interior of second container 324 (compare FIG. 3A and FIG. 3B). As shown in FIG. 3B, there is now a greater amount of working fluid 326 a in second container 324 a than there is in first container 316 a. The warming of working fluid 319 a in first container 316 a and cooling of working fluid 326 a in second container 324 a can be switched after a fluid-exchange cycle so that the working fluid in first container 316 a is cooled while the working fluid in second container 324 a is warmed, which can give rise to another fluid-exchange cycle, and so on for an indefinite number of subsequent fluid-exchange cycles.
The state of flip-flopping the cooling and heating of both containers is shown in FIG. 3C where a supply of warmer HTF 312 b is allowed to warm working medium 326 b while a supply of cooler HTF 312 b is used to cool working medium 319 b from the interior of first container 316 b.
FIG. 3D illustrates an embodiment where circulation member 318 c forms a part of an interior wall of first container 316 c rather than being disposed further within first container 316 c as shown in FIG. 3A. Also shown in FIG. 3D is that heat-conducting structure 322 c may form a portion of an interior wall of second container 324 c as opposed to merely being disposed within second container 324 c as shown in FIG. 3A.
Turning now to FIG. 4A, another simplified view of a high-level overview of the present invention is shown in which the active heating and cooling of the working medium takes places within only one of a pair of containers. Various valves, pumps, controllers, etc., are not shown in this view so as not to obscure explanation of these high-level aspects of the invention. As will be discussed later, FIG. 4A illustrates the beginning of a phase equivalent to the end of that illustrated in FIG. 4D. In this embodiment, warmer HTF 412 is circulated through heat-conducting structure 414 in an interior of first container 416 to warm working fluid 419. Heat energy is transferred from warmer HTF 412 into working fluid 419 which, in turn, results in an increase in the pressure of working fluid 419. FIG. 4B illustrates the effects of the increase in pressure within first container 416 a, as a fluid exchange has taken place and an amount of working fluid 419 a has flowed from an interior of first container 416 a to an interior of second container 424 a.
Turning now to FIG. 4C, a supply of cooler HTF 420 b is circulated through heat-conducting structure 414 b in an interior of first container 416 b to cool working medium 419 b inside first container 416 b. Heat energy is absorbed from working fluid 419 b into cooler HTF 420 b which, in turn, results in a decrease in the pressure of working fluid 419 b. FIG. 4D illustrates the effects of the decrease in pressure within first container 416 c, as a fluid exchange has taken place and an amount of working fluid 426 c has flowed from an interior of second container 424 c to an interior of first container 416 c. As was mentioned previously, the end of the phase illustrated in FIG. 4D is equivalent to that illustrated in the beginning of that illustrated in FIG. 4A. A repetition of the process described can give rise to an indefinite number of subsequent fluid-exchange cycles.
Turning now to FIG. 5, an illustrative method for operating an embodiment of the present invention is provided and referenced generally by the numeral 500. At a step 510, a determination is made as to whether a sufficiently high pressure differential between the two containers exists. With reference to FIG. 2A, in one embodiment, controller 252 determines whether a sufficiently high pressure differential exists. A threshold pressure differential could be preprogrammed or determined on the fly. In alternative embodiments, the pressure differential can be determined in real time to be sufficiently high to begin a fluid-exchange cycle. If a sufficiently high pressure differential between two or more containers as the case may be does not exist, then a step 512 persists wherein the temperature within one or more of the containers is internally varied so as to increase the pressure differential between the two containers. For example, more heat may be transferred to one container, and/or heat may be withdrawn from the other container, and/or both of these may occur at the same time. In one embodiment, heat transfer is facilitated by circulating heat-transfer fluid as previously described. In alternative embodiments, an ignitable fluid may be ignited within a container to generate heat in that container.
Step 512 of internally varying the temperature within one or more of the containers persists until a sufficiently high pressure differential with respect to two containers (for example) exists. This is indicated by arrow 514 reverting back to an illustrative determination step regarding the extent of the pressure differentials between the two containers.
But if a sufficiently high pressure differential does exist between the containers at a step 510, then the illustrative process will advance to step 516, wherein the working fluid is allowed to be exchanged from one container to the other and as it does it performs work, or generates electricity. In one embodiment, allowing the working fluid to be exchanged from one container to the other may include opening a fluid exchange valve, such as main valve 250 of FIG. 2A and allowing the working fluid under relatively higher pressure to flow into the container having a relatively lower pressure. As the working fluid flows from one container to the other, turbine 270 and generator 272 are stimulated, which, in turn, can be used to generate electricity.
The fluid-exchange cycle is allowed to persist for as long as a threshold pressure differential between the two containers exists. This threshold pressure differential may be monitored by controller 252 in one embodiment. Thus, at a step 518, a determination is made as to whether a sufficiently low pressure differential exists between the two containers to stop a fluid-exchange cycle. If not, then the fluid-exchange cycle of step 516 is allowed to persist as fluid moves from a higher-pressure environment to a lower-pressure environment. But if the pressure differential between the two tanks has reduced to a sufficiently lower amount, then the process reverts to step 512, wherein the working fluid is prevented from being exchanged between the two containers. In one embodiment, this is accomplished by closing a fluid-exchange valve such as main valve 250 as shown in FIG. 2A. With this valve closed, fluid is not allowed to be exchanged between the two containers, and the temperature associated with each of the respective working mediums may be internally varied so as to rebuild back up a pressure differential between the two containers that can be used to motivate subsequent fluid-exchange cycles. In this way, an indefinite number of fluid-exchange cycles can occur, each of which generates electricity. Turbine 270 may also be referred to as an energy converter because it converts a first type of energy into a second type of energy. If electricity is the desired end product, and turbine 270 cannot by itself generate electricity, then turbine 268 in connection with generator 272 may be referred to as an energy converter as they convert mechanical energy into electrical energy.
FIG. 6 illustrates still another illustrative operating environment suitable for practicing an embodiment of the present invention. In this illustration, greater detail is shown as well as additional features such as utilizing multiple containers to reduce the time between fluid-exchange cycles. Four containers are shown instead of two to illustrate the general concept; however, a larger number of containers could be used so as to provide a continuously rotating turbine that continuously generates electricity. The following description is provided with reference to FIG. 6.
An HTF pump 10 a stimulates cyclical movement of a hotter HTF 12 from a hotter HTF supply reservoir 14 through an HTF valve system 16 through an HTF flow path 18 a causing hotter HTF 12 to pass through a solar radiation receiver tube 20. A reflecting device, such as a parabolic mirror 22 or similar light/heat-focusing device is positioned so that it reflects solar radiation onto solar radiation receiver tube 20, causing hotter HTF 12 within solar radiation receiver tube 20 to absorb heat energy.
Other components can be utilized to facilitate varying heat levels of hotter HTF 12. Describing all such components would be impractical, but a few are mentioned as illustrative. These components can be used as a primary source of heat energy, especially when solar exposure to mirror 22 is unavailable or impeded. They may also be used as a source of heat energy prior to the passage of hotter HTF 12 through HTF flow path 18 a to preheat the HTF. Still again, these components may provide a source of additional heat energy after the passage of hotter HTF 12 through HTF flow path 18 a to post-heat the HTF. Illustrative such components include a natural gas heater 24 and a natural gas heat pump 26 with a natural gas supply 28 or heat storage reservoir 30.
Hotter HTF 12 can be stimulated by HTF pump 10 b through HTF flow path 18 b. When natural gas heater 24 is operational, it burns natural gas from natural gas supply 28 and heat energy is transferred from natural gas heater 24 into hotter HTF 12.
Hotter HTF 12 can be stimulated by pump 10 c through flow path 18 c. When natural gas heat pump 26 is operational, natural gas heat pump 26 burns natural gas from natural gas supply 28 and heat energy is transferred from natural gas heat pump 26 into natural gas heat pump hot reservoir 32 and, in turn, into hotter HTF 12.
To conserve heat energy for later use if desired, previously heated hotter HTF 12 can be stimulated by pump 10 d through flow path 18 d through a heat storage reservoir 30. In one embodiment, the temperature of the hotter HTF 12 is hotter than the working medium within heat storage reservoir 30 and, therefore, heat energy is transferred from hotter HTF 12 into the working medium within reservoir 30.
Such working medium within reservoir 30 could be any suitable material, such as salt, resulting in heated salt or molten salt. When heat energy is needed to be extracted from reservoir 30, hotter HTF 12 can again be stimulated by pump 10 d through flow path 18 d through reservoir 30. Because heat is being extracted, the temperature of hotter HTF 12 is cooler than the working medium within heat storage reservoir 30 in this embodiment. Heat energy is transferred from the working medium into hotter HTF 12.
Any available source of heat energy, whether from a storage facility, such as heat storage reservoir 30, or an arrangement such as parabolic mirror 22 and solar radiation receiver tube 20, natural gas heater 24, natural gas heat pump 26, or other sources such as industrial heat (not illustrated) can be used individually or in combination with one another to manipulate heat energy in hotter HTF 12. Even ambient environmental heat (not illustrated) can be used if the ambient temperature is warm enough to raise the temperature within hotter HTF 12.
An HTF pump 10 e stimulates the cyclical movement of a cooler HTF 34 from a reservoir 36 through a valve system 16 through a fluid flow path 18 e causing the cooler HTF 34 to pass through geothermal cooling system 38, causing the temperature of cooler HTF 34 to adjust toward the temperature within cooling system 38.
Other components may be utilized to reduce the heat energy of cooler HTF 34 according to various embodiments of the present invention. These components can be as primary sources of reductions in heat energy, as a source of reductions in heat energy prior to (pre-cooling) the passage of cooler HTF 34 through geothermal cooling system 38, or as a source of additional reductions in heat energy after (post-cooling) the passage of cooler HTF 34 through HTF geothermal cooling system 38. Included in an embodiment in regard to pre-cooling, post-cooling, or alternative cooling sources are natural gas heat pump 26 with natural gas supply 28, and a geothermal cooled reservoir 40.
Cooler HTF 34 can be stimulated by a pump 10 f through a flow path 18 f. When natural gas heat pump 26 is operational, it burns natural gas from natural gas supply 28. Heat energy is reduced within natural gas heat pump cold reservoir 42 and, in turn, within cooler HTF 34.
To conserve a supply of cooler HTF 34 in anticipation of later use, previously cooled cooler HTF 34 can be stimulated by pump 10 g into geothermal cooled reservoir 40. Cooler HTF 34 can be extracted from geothermal cooled reservoir 40 via HTF pump 10 h.
Any available mechanism or method to reduce heat energy may be utilized. A storage facility, such as geothermal cooled reservoir 40, may be utilized as well as an active source of reductions in heat energy, such as natural gas heat pump 26, or passive heat reductions, such as HTF geothermal cooling system 38. Various components and methods can be used individually or in combination with one another to reduce the heat energy in cooler HTF 34. Even ambient environmental cooling (not illustrated) can be used if the ambient temperature is cool enough to effect a reduction of temperature within cooler HTF 34.
In one embodiment, the operation includes four primary phases: a first temperature-changing phase, a first fluid-exchange phase, a second temperature-changing phase, and a second fluid-exchange cycle. The following is an illustrative description of the phases.
During Phase I, heat energy is added to a working fluid in a container. Examples of a working fluid include air, dry air, or other primarily gaseous substance that responds to a rise in temperature with a rise in pressure. The introduced heat causes the pressure associated with the working fluid to increase.
Phase II primarily involves the transfer of working fluid from the container, stimulating a motive power device. This transfer of working fluid out of the container causes a lowering of the pressure of the working fluid within the container.
Phase III primarily involves the lowering of the temperature of the remaining working fluid within the container resulting in a further lowering of pressure.
Phase IV primarily involves the transfer of working fluid from higher pressure sources into the subject container.
In one embodiment, container 44 a principally illustrates the operations of Phase I; container 44 b principally illustrates Phase II; container 44 c principally illustrates Phase III; and container 44 d principally illustrates Phase IV. Although the pressure of the working medium within each of the containers in some embodiments will likely remain significantly above normal ambient pressure throughout the four phases, three levels of pressure will be referenced: moderate, heightened, and lowered (relatively). These correspond to the outline of operations just described.
Container 44 a contains working fluid 46 a under pressure. At the start of Phase I, the pressure of working fluid 46 a within container 44 a may be relatively moderate (see the above pressure scheme) and equivalent to the end of Phase IV, which will be discussed in greater detail below. During Phase I, HTF pump 10 i stimulates the cyclical movement of hot (although references to “hot” or “cool” may be made herein, such references make reading easier, but actually are relative terms; e.g., “hotter than at a prior state or in another container” or “cooler that at a prior state or in another container) HTF fluid 12 through flow path 18 g, including internal heating and cooling conduit 48 a—disposed within the internal working fluid chamber of container 44 a—and HTF pressure regulator 50 a.
As hot HTF passes through internal heating and cooling conduit 48 a, conduit 48 a heats up, which, in turn, transfers heat to working fluid 46 a in container 44 a. The increased temperature of the working fluid 46 a in container 44 a causes an increase in pressure of the working fluid 46 a in container 44 a.
In one embodiment, fans 52 a and 52 b in container 44 a may provide forced convection between internal heating and cooling conduit 48 a and the working fluid 46 a in container 44 a via the circulation of working fluid 46 a in container 44 a in the direction of the illustrative arrows. Of course the path may be in a different direction. Even still, there may be no circulation in embodiments that do not use such fans.
A controller 54 monitors the temperature of the hot HTF via temperature gauges 56 a and 56 b in one embodiment. Controller 54 also monitors the temperature and pressure of working fluid 46 a in container 44 a via working fluid temperature gauge 58 a and working fluid pressure gauge 60 a, respectively. Controller 54 periodically manages the operations of HTF pump 10 i and HTF pressure regulator 50 a so as to maintain a close relationship between the fluid pressure of the hotter HTF 12 within internal heating and cooling conduit 48 a and the fluid pressure of the working fluid 46 a in container 44 a. Connections between controller 54 and other devices have been omitted.
This function described of closely balancing the pressure of hotter HTF 12 within internal heating and cooling conduit 48 a with the static or changing pressure of the working fluid 46 a in container 44 a by manipulating the fluid pressure of hotter HTF 12 within internal heating and cooling conduit 48 a via the management of HTF pressure regulator 60 a and information from HTF temperature gauges 56 a and 56 b and of working fluid pressure gauge 56 a, will hereinafter be referred to as “pressure balancing”.
In embodiments that require pressure balancing (as some do not, depending on the level and strength of available materials and the level of desired efficiency), it will be present in its equivalent forms during all phases described (for that embodiment). The primary purpose of pressure balancing, when included, is to minimize the required pressure tolerances and, therefore, the thickness of the materials, likely copper or other highly heat-conductive materials, used for the construction of internal heating and cooling conduit 48 a or its equivalent.
Inner wall insulation 62 a is disposed on the inner wall of container 44 a primarily in an effort to minimize the amount of heat energy transferred to or through container 44 a. As previously mentioned, intentional temperature manipulations of the working fluid occur internally; that is, from within the containers, rather than by way of external factors (factors external to the containers).
Emergency pressure relief valve 64 a is included with container 44 a in case of malfunctions or unanticipated pressures that would otherwise compromise the integrity of container 44 a or any of the other applicable components in one embodiment.
Working fluid transfer valve 66 a and working fluid transfer conduit 68 a, controlled by controller 54, are included with container 44 a. During Phase I, they remain in a closed position. The primary functions of working fluid transfer valve 66 a and working fluid transfer conduit 68 a will be explained in connection with the discussions of the remaining phases to follow.
Geothermal working fluid valves 70 a and 70 b, which, during Phase I, remain in a closed position, geothermal working fluid cooling flow path 72 a, geothermal working fluid cooling system 74 a, working fluid temperature gauge 58 b, working fluid pressure gauge 60 b, and emergency pressure relief valve 64 b are included with container 44 a in one embodiment. The primary functions of geothermal working fluid valves 70 a and 70 b, geothermal working fluid cooling flow path 72 a, geothermal working fluid cooling system 74 a, working fluid temperature gauge 58 b, working fluid pressure gauge 60 b, and emergency pressure relief valve 64 b will be explained within the discussions of the remaining phases to follow.
When the temperature and pressure of working fluid 46 a within container 44 a reach desired levels, Phase II begins in this embodiment. Container 44 b is assumed to have previously transitioned through Phase I and, therefore, contains working fluid 46 b under a relatively heightened fluid pressure.
Optionally, just as in Phase I, during Phase II, HTF pump 10 j could continue to stimulate the cyclical movement of hotter HTF 12 through internal HTF flow path 18 h, including internal heating and cooling conduit 48 b, disposed within the internal working fluid chamber of container 44 b, and HTF pressure regulator 50 b, which could continue to add heat energy to working fluid 46 b. Similarly, fans 52 c and 52 d, disposed within container 44 b, can continue to provide forced convection between internal heating and cooling conduit 48 b and the working fluid 46 b in container 44 b via the circulation of working fluid 46 b in container 44 b.
Controller 54 monitors the temperature of the hotter HTF 12 via HTF temperature gauges 56 c and 56 d. Controller 54 also monitors the temperature and pressure of the working fluid 46 b in container 44 b via working fluid temperature gauge 58 b and working fluid pressure gauge 60 b, respectively. Controller 54 periodically manages the operations of HTF pump 10 j and HTF pressure regulator 50 b so as to maintain a close relationship between the fluid pressure of the hotter HTF 12 within internal heating and cooling conduit 48 b and the fluid pressure of the working fluid 46 b in container 44 b.
Inner wall insulation 62 b is disposed on the inner wall of container 44 b primarily in an effort to minimize the amount of heat energy transferred to or through container 44 b. Emergency pressure relief valve 64 c is included with container 44 b in case of malfunctions or unanticipated pressures that would otherwise compromise the integrity of container 44 b or any of the other applicable components.
Working fluid transfer valve 66 b and working fluid transfer conduit 68 b, controlled by controller 54, are included with container 44 b. Characteristic of Phase II, working fluid transfer valve 66 b is opened and working fluid 46 b is allowed to flow from container 44 b through working fluid transfer conduit 68 b to working fluid valve system 76 where the working fluid 46 b from container 44 b is routed through air turbine flow path 78, working fluid pressure regulator 80, air turbine 82, and post-turbine geothermal working fluid cooling system 84.
Working fluid pressure regulator 80, controlled by controller 54, manages the fluid pressure of the working fluid 46 b passing toward air turbine 82. Subject to the operation of working fluid pressure regulator 80, as working fluid 46 b passes through air turbine 82, the working fluid 46 b causes air turbine 82 to react, generating motive power until the net pressure differential between the working fluid 46 b on the entry side of air turbine 82 and the working fluid 46 b on the exit side of air turbine 82 is equal to or less than the minimum pressure differential required to stimulate air turbine 82 and related loads.
Generator 86 is coupled to air turbine 82 in order to generate electricity in response to the motive power of air turbine 82. Following the exit of working fluid 46 b from container 44 b, the pressure of working fluid 46 b still within container 44 b is reduced from its relatively heightened level, referred to afterwards as moderate, in reference to the previously discussed pressure scheme. Generator 86 may be part of turbine 82.
As working fluid 46 b passes through post-turbine geothermal working fluid cooling system 84, the working fluid 46 b adjusts toward the temperature within post-turbine geothermal working fluid cooling system 84. Geothermal working fluid valves 70 c and 70 d, which, during Phase II, remain in a closed position, geothermal working fluid cooling flow path 72 b, geothermal working fluid cooling system 74 b, working fluid temperature gauge 58 d, working fluid pressure gauge 60 d, and emergency pressure relief valve 64 d are included with container 44 b. The primary functions of geothermal working fluid valves 70 c and 70 d, geothermal working fluid cooling flow path 72 b, geothermal working fluid cooling system 74 b, working fluid temperature gauge 58 d, working fluid pressure gauge 60 d, and emergency pressure relief valve 64 d will be explained within the discussions of the remaining phases to follow.
When the pressure of working fluid 46 b within container 44 b reaches a desired level, working fluid transfer valve 66 b is closed by controller 54 and Phase III could commence. Container 44 c is assumed to have previously transitioned through Phase I and Phase II and, therefore, contains working fluid 46 c again at a relatively moderate fluid pressure, in reference to the previously discussed pressure scheme.
During Phase III, HTF pump 10 k stimulates the cyclical movement of cooler HTF 34, cooled by one of the components or methods of heat reduction discussed previously or other device or method, through HTF flow path 18 i, including internal heating and cooling conduit 48 c, disposed within the internal working fluid chamber of container 44 c, and HTF pressure regulator 50 c.
As cooler HTF 34 passes through inner internal heating and cooling conduit 48 c, internal heating and cooling conduit 48 c cools down and, in turn, heat is transferred from the working fluid 46 c in container 44 c.
Geothermal working fluid valves 70 e and 70 f, controlled by controller 54, geothermal working fluid cooling flow path 72 c, geothermal working fluid cooling system 74 c, working fluid temperature gauge 58 e, working fluid pressure gauge 60 e, and emergency pressure relief valve 64 e are included with container 44 c. When desired, controller 54 opens geothermal working fluid valve 70 e and the remaining pressure within the working fluid 46 c remaining within container 44 c may force a portion of the working fluid 46 c remaining within container 44 c into geothermal working fluid cooling flow path 72 c [optionally, a turbine or other energy converter (not illustrated) could be placed at or near the beginning of geothermal working fluid cooling flow path 72 c to capture a portion of the energy provided by the fluid initially flowing into geothermal working fluid cooling flow path 72 c motivated by any excess pressure of the working fluid 46 c remaining within container 44 c as compared to the fluid already resident in the geothermal working fluid cooling flow path 72 c]. Thereafter, when desired, using information from working fluid pressure gauge 60 c, disposed with container 44 c, and working fluid pressure gauge 60 e, disposed with geothermal working fluid cooling flow path 72 c, controller 54 opens geothermal working fluid valve 70 e which, in turn, opens working fluid cooling flow path 72 c through geothermal working fluid cooling system 74 c.
Fans 52 e and 52 f, disposed within container 44 c, stimulate the movement of the working fluid 46 c remaining within container 44 c into working fluid flow path 72 c by blowing the working fluid 46 c remaining within container 44 c in the direction of the illustrative arrows (alternately, force could also be provided in the opposite direction). Working fluid 46 c remaining within container 44 c is, to the extent possible and practical, replaced by working fluid exiting geothermal working fluid cooling system 74 c.
The combination of the cooling of internal heating and cooling conduit 48 c and the stimulation of movement of the working fluid 46 c remaining within container 44 c into working fluid flow path 72 c and, in turn, the stimulation of working fluid 46 c from geothermal working fluid cooling system 74 c into container 44 c, results in a decreased temperature of the working fluid 46 c in container 44 c than at the start of Phase III which, in turn, results in a lowered pressure of the working fluid 46 c in container 44 c.
Controller 54 monitors the temperature of the cooler HTF 34 via HTF temperature gauges 56 e and 56 f. Controller 54 also monitors the temperature and pressure of the working fluid 46 c in container 44 c via working fluid temperature gauge 58 c and working fluid pressure gauge 60 c, respectively. Controller 54 also monitors the temperature and pressure of the working fluid 46 c entering container 44 c from geothermal working fluid cooling system 74 c via working fluid temperature gauge 58 e and working fluid pressure gauge 60 e, respectively. Controller 54 periodically manages the operations of HTF pump 10 k and HTF pressure regulator 50 c so as to maintain a close relationship between the fluid pressure of the cooler HTF 34 within internal heating and cooling conduit 48 c and the fluid pressure of the working fluid 46 c in container 44 c.
Inner wall insulation 62 c is disposed on the inner wall of container 44 c primarily in an effort to minimize the amount of heat energy transferred to or through container 44 c. Emergency pressure relief valve 64 f is included with container 44 c in this embodiment in case of malfunctions or unanticipated pressures that would otherwise compromise the integrity of container 44 c or any of the other applicable components. Emergency pressure relief valve 64 e is included with working fluid flow path 72 c in case of malfunctions or unanticipated pressures that would otherwise compromise the integrity of working fluid flow path 72 c or any of the other applicable components.
Working fluid transfer valve 66 c and working fluid transfer conduit 68 c, controlled by controller 54, are included with container 44 c, and, during Phase III, remain in a closed position. The functions of working fluid transfer valve 66 c and working fluid transfer conduit 68 c were partially explained within the discussions of Phase II and will be continued within the discussions of Phase IV.
When the temperature and pressure of working fluid 46 c within container 44 c reach desired levels, geothermal working fluid valves 70 e and 70 f can be closed by controller 54, and Phase IV could commence.
Container 44 d is assumed to have previously transitioned through Phases I through III and, therefore, contains working fluid 46 d at a lowered fluid pressure. Optionally, just as in Phase III, during Phase IV, HTF pump 10 l could continue to stimulate the cyclical movement of cooler HTF 34 through HTF flow path 18 j, including internal heating and cooling conduit 48 d, disposed within the internal working fluid chamber of container 44 d, and HTF pressure regulator 50 d, which could continue to reduce the heat energy within the working fluid 46 d within container 44 d. Fans 52 g and 52 h, disposed within container 44 d, can provide forced convection between internal heating and cooling conduit 48 d and the working fluid 46 d in container 44 d via the circulation of working fluid 46 d in container 44 d in the direction of the illustrative arrows (a circulatory path could also be attained in the opposite direction).
Controller 54 monitors the temperature of the cooler HTF 34 via HTF temperature gauges 56 g and 56 h. Controller 54 also monitors the temperature and pressure of the working fluid 46 d in container 44 d via working fluid temperature gauge 58 g and working fluid pressure gauge 60 g, respectively. Controller 54 periodically manages the operations of HTF Pump 10 l and HTF pressure regulator 50 d so as to maintain a close relationship between the fluid pressure of the cooler HTF 34 within internal heating and cooling conduit 48 d and the fluid pressure of the working fluid 46 d in container 44 d.
Inner wall insulation 62 d is disposed on the inner wall of container 44 d primarily in an effort to minimize the amount of heat energy transferred to or through container 44 d. Emergency pressure relief valve 64 g is included with container 44 d in case of malfunctions or unanticipated pressures that would otherwise compromise the integrity of container 44 d or any of the other applicable components.
Geothermal working fluid valves 70 g and 70 h, controlled by controller 54, geothermal working fluid cooling flow path 72 d, geothermal working fluid cooling system 74 d, working fluid temperature gauge 58 g, working fluid pressure gauge 60 g, and emergency pressure relief valve 64 g are included with container 44 d. The primary functions of geothermal working fluid valves 70 g and 70 h, geothermal working fluid cooling flow path 72 d, geothermal working fluid cooling system 74 d, working fluid temperature gauge 58 g, working fluid pressure gauge 60 g, and emergency pressure relief valve 64 g were explained within the discussions of the previous phases.
Working fluid transfer valve 66 d and working fluid transfer conduit 68 d, controlled by controller 54, are included with container 44 d. Characteristic of Phase IV, working fluid transfer valve 66 d is opened and working fluid 46 d is allowed to flow into container 44 d from working fluid transfer conduit 68 d from working fluid valve system 76 where the working fluid 46 d into container 44 d is routed from air turbine flow path 78. The origination of the flow of working fluid 46 d is from one or more containers operating in Phase II of the four phase cycle.
When the pressure of working fluid 46 d within container 44 d reaches a desired level, referred to here as moderate in reference to the above pressure scheme, working fluid transfer valve 66 d is closed by controller 54, and Phase I could commence.
Detailed drawings of HTF valve system 16 and working fluid valve system 76 were omitted from FIG. 5. The working of these valve systems are routine and have been represented by generic shapes which represent a sufficient array of conduits and valves to direct the flow of fluids as directly and indirectly described in this detailed description of the invention.
In the above description, various valves were to be controlled by controller 54, and various gauges were to provide information to controller 54. But some embodiments do not require all of these gauges and valves. Certain valves that automatically open after being subjected to a threshold pressure may be used. HTF temperature gauges 56 i through 56 v are included to provide information to controller 54 so that controller 54 can monitor the temperature of HTFs 12 and 34 in order to optimize operations and the phases for each container in one embodiment. Similarly, working fluid temperature gauges 58 i through 58 n and working fluid pressure gauges 601 through 60 n are included to provide information to controller 54 so that controller 54 can monitor the temperature and pressure of the working fluid 46 d within the working fluid transfer conduits 68 a through 68 d and air turbine flow path 78 in order to optimize operations and the phases for each container. Emergency pressure relief valves 641 through 64 n are included with working fluid transfer conduits 68 a through 68 d and air turbine flow path 78 in case of malfunctions or unanticipated pressures that would otherwise compromise the integrity of working fluid transfer conduits 68 a through 68 d and air turbine flow path 78 or any of the other applicable components.
The shape of internal heating conduits 48 a through 48 d could vary, as the goal of the conduits is the transfer of heat energy to and from the working fluid 46 d within containers 44 a through 44 d, depending on the phase in process. One shape of particular interest, not illustrated, may be that of a coil across the cross-section of the containers, so that the forced convection currents will cause working fluid 46 d to pass very close to a portion of the coil. There may be one or more heating conduits within a given container in order to provide a faster rate of heat transfer.
The cooling of working fluid 46 d within post-turbine geothermal working fluid cooling system and during the operations of Phase III add to the development of the potential energy between the relatively heightened pressure levels at the end of Phase I and the lowered pressure levels at the end of Phase III, just as the adding of heat energy to working fluid 46 d during Phase I adds to the development of the potential energy. This potential energy, resulting from the contrast and use of both additional heat energy and reductions of heat energy, is particularly adaptive to the use of heat pump technologies. Many heat pump applications emphasize the use of only the “hot end” or the “cold end” of the heat pump. The present invention is capable of making use of the entire cycle of heat pump technology and, therefore, may be particularly efficient in the use of the energy consumed by the heat pump.
In order to minimize the heat conducted into the materials used for the construction of the working fluid conduits or other components, insulation could be included on the outside or the inside of the conduits, or both, or other components, as a heat conduction barrier, where appropriate.
In one embodiment, in order to attempt to capture a portion of the heat energy remaining within internal heating and cooling conduit 48 c and working fluid 46 c at the start of Phase III (from the end of phase II), an initial portion of the cooler HTF 34 used in phase III, warmed by such remaining heat energy, may be subjected to one or more of the processes used to heat or reheat hotter HTF 12 and combined with hotter HTF 12 within such processes (for use in subsequent phases I and II).
Other embodiments, either more complex or refined or simpler are possible. For instance, the description above includes a computer controller to operate an array of valves and consider information from an array of gauges. Further, emergency pressure relief valves are included and several of the conduits and other parts are insulated to minimize heat losses. However, many of these components are optional.
An array of only four containers, one air turbine, and one generator was described with reference to FIG. 6. But as mentioned, a larger number of containers is probable for more continuous operations and a larger number of other components is possible. For instance, if a larger number of containers are included, the initiation of the four phases could be staggered so that a reasonably consistent and steady flow of working fluid could be maintained through the air turbine, which may alleviate the need for a pressure regulator in regard to the flow of working fluid.
Turning now to FIG. 7, another simplified view of a high-level overview of an embodiment of the present invention is shown. In this embodiment, warmer HTF 712 is motivated through valve 782 into the interior of first container 716. In some embodiments pump 718 can be utilized to motivate HTF 712 to flow into the interior via interior heat-transfer component 714 to warm working fluid 719. In this embodiment, the warmer HTF 712 is allowed to come into direct contact with working fluid 719 and to transfer heat without being contained in a conduit or other component.
Heat transfer component 714, in this embodiment, can be a port, or a nozzle-type component protruding through a void in first container 716 that is sufficient for the introduction of warmer HTF 712 (in some embodiments, warmer HTF 712 may be superheated). In this embodiment, excess HTF 712 may accumulate at or near an HTF exit area, where valve 788 is included to control an accumulation of HTF 712.
A supply of cooler HTF 720 is motivated through valve 784 (by pump 734 in some embodiments) and into the interior of second container 724 via interior heat-transfer component 722 to cool working fluid 726. Various valves, pumps, controllers, etc., are not shown in this view so as not to obscure explanation of these high-level aspects of the invention. For instance, a layer of insulation may be included (as with other embodiments) to reduce the transfer of heat between working fluid 719 and first container 716 or between HTF 712 and first container 716.
As working fluid 719 within first container 716 warms, and working fluid 726 within second container 724 cools, working fluid 719 is motivated to move in the direction indicated which, in turn, motivates working fluid to pass through energy converter 770 and stimulate generator 772, if it is different than energy converter 670.
Alternating the heating and cooling of the working fluid within the first and second containers can lead to further working-fluid exchange cycles in both directions.
Turning now to FIG. 8, another simplified view of a high-level overview of an embodiment of the present invention that includes a piston 870 as a type of energy converter is shown. As in the embodiment just mentioned, this embodiment contemplates warmer HTF 812 being motivated through valve 882 (by pump 818 in some circumstances) and into the interior of first container 816 via interior heat-transfer component 814 to warm working fluid 819. Again, HTF 812 is allowed to come into direct contact with working fluid 819. The heat transfer component 814, in this embodiment, may be a port or nozzle-type component or just be a void in first container 816. Valve 888 can be included to control an accumulation of HTF 812. A supply of cooler HTF 820 is motivated through valve 884 by pump 834 and into the interior of second container 824 via interior heat-transfer component 822 to cool working fluid 826.
As working fluid 819 within first container 816 warms and working fluid 826 within second container 824 cools, the resulting pressure differential between working fluids 819 and 826 results in a force that motivates piston 870, which stimulates shaft 872. Piston 870 and its coupling to shaft 872 are meant to be shown schematically. Alternating the heating and cooling of the working fluid within the first and second containers can lead to further working fluid exchange cycles in both directions.
Many different arrangements of the various components depicted, as well as components not shown, are possible without departing from the spirit and scope of the present invention. For example, the geothermal working fluid cooling system 74 c and related components from FIG. 6 could be used to cool working fluid 826 within second container 824 instead or in combination with cooler HTF 820 and its related components above.
In the embodiments discussed above, various methods and systems were described to effect heat transfer from the heat-transfer fluid to the working fluid. Many of these embodiments contemplate an indirect heat-transfer process. That is, some medium contained the heat-transfer fluid, and by virtue of conduction, convection or a combination thereof, heat is transferred from the HTF to the medium containing the HTF and then from the medium to the working fluid. In some of the illustrative embodiments, this containing medium took the form of conduit. In other embodiments, it takes the form of an inner wall having voids that HTF could flow through.
But in still other embodiments, heat transfer may be facilitated directly (as mentioned above). That is, under appropriate conditions, the HTF itself can be introduced into the container(s) such that it is in direct communication with the working fluid so that heat from the HTF can be directly communicated to the working fluid.
For example, the HTF may be introduced into a container from one or more inlets into the containers. In some embodiments, the HTF may be introduced as droplets. Any pressure exerted from an interior of a container may be overcome by utilizing a pump to motivate the HTF to flow into a chamber of the container. Any collection of HTF may be discharged by way of a discharge valve. Examples of these embodiments were shown in FIGS. 7 & 8. The process does not need to be continuous or even regular, and it can be used alone or in combination with the aforementioned indirect-heating structures. For example, in some embodiments, the HTF may intentionally be allowed to sweat or to leak out of pores or other voids of the structures, such as conduit tubing, under certain conditions. An illustrative condition may include when the pressure within a container drops below a certain threshold. At this point, the HTF may be allowed to seep into a chamber. This may occur by virtue of the relative pressure difference between an interior of the conduit and an interior of the container.
Embodiments of the present invention have been described with the intent to be illustrative rather than restrictive. Alternative embodiments will become apparent to those skilled in the art that do not depart from its scope. A skilled artisan may develop alternative means of implementing the aforementioned improvements without departing from the scope of the present invention.
It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations and are contemplated within the scope of the claims. Not all steps listed in the various figures need be carried out in the specific order described. The use of the term “optionally” in some places is not meant to imply a necessity in other places where it is not used.

Claims

1. An energy-conversion apparatus, comprising:

a first container to contain working fluid under pressure;

a first heat-transfer component in the first container;

a second container to contain working fluid under pressure; and

an energy converter coupled to the first and second containers that performs work in response to a flow of working fluid through the energy converter, wherein the flow is motivated by varying a pressure within the first container caused by the first heat-transfer component.

2. The apparatus of claim 1, wherein the first heat-transfer component is operable to internally manipulate an internal temperature within the first container.

3. The apparatus of claim 2, wherein the first heat-transfer component is operable to provide heat to or remove heat from an interior of the first container.

4. The apparatus of claim 3, wherein the first heat-transfer component includes one or more of:

an arrangement of conduit in an interior cavity of the first container that allows for a circulation of a heat-transfer fluid that facilities heat transfer;

an interior wall of the container exposed to the interior cavity, the interior wall including voids though which heat-transfer fluid can be circulated; and

an arrangement of conduit through which working fluid can flow and that is coupled to one or both of the first and second containers, the arrangement allowing a geothermal process to be utilized to effect heat transfer from or to the working fluid as it flows though the arrangement.

5. The apparatus of claim 4, wherein the heat-transfer fluid includes a gas, a liquid, or combination thereof.

6. The apparatus of claim 5, wherein the heat-transfer fluid is capable of being subjected to a temperature-changing process including one or more of:

utilizing solar energy to effect a temperature change;

utilizing geothermal heating or cooling to effect a temperature change;

utilizing a heat pump to effect a temperature change; or

utilizing an ignitable fuel source to effect the temperature change.

7. The apparatus of claim 6 wherein the ignitable fuel source is ignitable from within an interior of the first or second containers.

8. An energy-conversion apparatus, comprising:

a first container to contain working fluid under pressure;

a first heat-transfer component in the first container that is operable to manipulate an internal temperature of the first container (first internal temperature) from within the first container;

a second container to contain working fluid under pressure;

a second heat-transfer component in the second container that is operable to manipulate an internal temperature of the second container (second internal temperature) from within the second container; and

an energy converter coupled to the first and second containers that performs work in response to a flow of working fluid between the containers.

9. The apparatus of claim 8, wherein the first container is insulated.

10. The apparatus of claim 8, wherein the first heat-transfer component is further operable to internally manipulate the first internal temperature substantially independently of an ambient temperature of an environment.

11. The apparatus of claim 10, wherein the energy converter generates electricity via rotational motion.

12. The apparatus of claim 10, wherein the flow of the working fluid between the containers is urged by a difference in pressure within one of the containers compared to a pressure within the other of the containers, wherein the difference in pressure is induced by varying one or more of the first or second internal temperatures utilizing one or more of the first or second heat-transfer components.

13. The apparatus of claim 8, wherein the energy converter that performs work includes an energy converter that can be used to generate electricity.

14. The apparatus of claim 8, wherein the flow of working fluid between the containers includes a flow from the first container to the second container or a flow from the second container to the first container.

15. The apparatus of claim 8, further comprising a pressure-balancing component that reduces the pressure differential between the exterior of the first heat-transfer component and the interior of the first heat-transfer component below a threshold amount.

16. An energy-conversion apparatus that utilizes a heat-transfer fluid (HTF), the apparatus comprising:

a first container to contain working fluid under pressure;

a first inlet port that allows HTF to be introduced into an interior of the first container;

a second container to contain working fluid under pressure; and

an energy converter coupled to the first and second containers that performs work in response to a flow of working fluid through the energy converter, wherein the flow is motivated by internally varying a pressure within the first container caused by direct heat transfer between the HTF and the working fluid.

17. The apparatus of claim 16, further comprising a second inlet port that allows HTF to be introduced into an interior of the second container.

18. The apparatus of claim 16, further comprising an arrangement of conduit through which working fluid can flow and that is coupled to one or both of the first and second containers, the arrangement allowing a geothermal process to be utilized to effect heat transfer from or to the working fluid as it flows though the arrangement.

19. An energy-conversion apparatus, comprising:

a first container of working fluid under pressure;

a second container of working fluid under pressure coupled to the first container;

a first heat-transfer component in the first container that, without a need for heat conduction through an exterior surface of the first container, is operable to perform one or more of

(1) internally increase a temperature within the first container above a temperature within the second container, and/or

(2) internally decrease a temperature within the first container below a temperature within the second container; and

an energy converter coupled to the first container and to the second container and adapted to perform work in response to a force exerted upon it, the force created as a result of a change in pressure in at least the first container caused by an internal manipulation of an internal temperature within at least the first container.

20. The apparatus of claim 19, further comprising a second heat-transfer component in the second container that is operable to internally manipulate an internal temperature within the second container.

21. The apparatus of claim 20, wherein, without a need for heat conduction through an exterior surface of the first container, the second heat-transfer component is operable to perform one or more of:

internally increase a temperature within the second container above a temperature within the first container, and/or

to internally decrease a temperature within the second temperature below a temperature within the first container.

22. The apparatus of claim 19, wherein the first heat-transfer component is operable to alternately:

internally increase a temperature within the first container above a temperature within the second container or vice versa; and/or to

internally decrease a temperature within the first temperature below a temperature within the second container or vice versa.

23. The apparatus of claim 19, wherein the energy converter includes a piston.

24. An energy-conversion apparatus comprising:

a first container to contain working fluid under pressure, the first container including an inlet port;

a second container to contain working fluid under pressure; and

an energy converter coupled to the first and second containers that performs work in response to a flow of working fluid through the energy converter, wherein the flow is motivated by internally varying a pressure within the first container caused by varying a temperature of the working fluid in at least the first container.

25. The apparatus of claim 24, wherein the inlet port facilitates varying the temperature of the working fluid in the first container by directly exposing the working fluid to an effect from burning an ignitable fuel source burning within the container.

26. A method for converting energy by utilizing a system comprising first and second containers to contain working fluid under pressure coupled to an energy converter, the method comprising:

from within one or both of the first and second containers, varying an internal pressure; and

performing work as the energy converter is stimulated in response to a flow of working fluid motivated to pass through the energy converter by the varying internal pressure, wherein the varying of the internal pressure comprises effecting a temperature change from within the first container, thereby causing a resultant change in pressure.

27. The method of claim 26, wherein varying the internal pressure(s) of the container(s) comprises varying a temperature of the working fluid by introducing a heat-transfer fluid into the first and/or second container that is of such a temperature that can vary the internal pressure of the container(s).

28. The method of claim 27, wherein introducing the heat-transfer fluid includes varying a temperature of the heat transfer fluid;

29. The method of claim 26, wherein varying the temperature of the heat-transfer fluid includes one or more of:

utilizing solar energy to effect a temperature change;

utilizing geothermal heating or cooling to effect a temperature change;

utilizing a heat pump to effect a temperature change; or

utilizing an ignitable fuel source to effect the temperature change.

30. The method of claim 26, wherein varying the internal pressure(s) of the container(s) comprises varying a temperature of the working fluid by exposing the working fluid to an effect from burning an ignitable fuel source burning within the container.

31. A method for converting energy by utilizing a system comprising a first container to contain working fluid under pressure coupled by way of an energy converter to a second container to contain working fluid under pressure, the method comprising:

from within one or both of the first or second containers, varying an internal temperature to cause a resultant pressure differential that motivates the working fluid to flow between the first and second containers; and

performing work as working fluid flows through the energy converter between the containers in response to the pressure differential.

32. The method of claim 31, varying the internal temperature includes introducing heat to or withdrawing heat from the working fluid within the first or second containers.

33. The method of claim 32, wherein the introducing or withdrawing heat includes one or more of:

exposing an interior of at least one of the containers to the effects of a heat-transfer fluid;

circulating a heat-transfer fluid through a portion of conduit in the first or second containers;

utilizing a geothermal heating or cooling process; and

introducing and igniting an ignitable fuel within the first or second containers.

34. The method of claim 33, wherein the exposing includes circulating the heat-transfer fluid through one or more cavities that includes at least one surface that is in communication with the interior of the first or second containers.

35. The method of claim 32, wherein the heat-transfer fluid is subjected to a warming process prior to circulation through the one or more cavities.

36. The method of claim 35, wherein the warming process includes concentrating sunlight to a localized volume of the heat-transfer fluid.

37. The method of claim 31, wherein the performing work includes one or more of generating electricity, converting energy from a first form to another, and effecting motion.

38. A method for converting energy as working fluid flows between a first container that contains working fluid under pressure and a second container that contains working fluid under pressure, the method comprising stimulating an energy converter by inducing a fluid-exchange cycle through the energy converter by varying the pressure of at least one of the containers relative to the other by internally varying the temperature of the working fluid of at least one of the containers.

39. The method of claim 38, wherein internally varying the temperature of the working fluid of at least one of the containers includes internally varying the temperature substantially independently of an ambient temperature associated with an ambient environment in which the first or second containers are exposed.

40. A method for converting energy, comprising:

providing a first a container to contain working fluid under pressure, the first container substantially surrounding a first heat-transfer component that can internally change an internal temperature within the first container;

providing a second container to contain working fluid under pressure, the second container substantially surrounding a second heat-transfer component that can internally change an internal temperature within the second container;

providing an energy converter coupled to the first container and to the second container;

stimulating the energy converter with a flow of working fluid from the first container to the second container by internally varying a pressure within the first or second container by varying a temperature within the first or second container so that a first pressure differential between the two containers is sufficiently high that it motivates the flow until the differential pressure between the two containers reaches a desired low pressure differential; and

increasing the desired low pressure differential to a second sufficiently high pressure differential so as to motivate a flow of the working fluid from the second container to the first container by varying a temperature within the first or second containers.

41. The method of claim 40, wherein the energy converter includes an oscillating member.

42. The method of claim 41, wherein stimulating the energy converter includes utilizing the working fluid within the first container to exert a force against the oscillating member.

43. The method of claim 42, wherein utilizing the working fluid to exert the force against the oscillating member includes heating a heat-transfer fluid prior to it entering an interior of the first container.