Patent Application
20100192566
The present disclosure relates to systems and methods for capturing energy from direct and waste thermal sources. More particularly, the present disclosure relates to systems and methods for producing electricity by extracting energy from hot gases such as exhaust gas generated by internal combustion engines and from solar concentrators.
Two major classes of engines are used to convert heat energy to mechanical energy and/or electrical energy—these being internal combustion (IC) and external combustion (EX) engines. Internal combustion engines dominate the transportation industry while the major applications of external combustion engines are found in the power generation industry where steam powered turbines are still a major application of the external combustion principle.
Stirling engines (SE) are external combustion engines with higher energy density than piston-based steam engines that may be as energetically efficient as internal combustion engines. Like steam power, SE's suffer relative to IC engines in having less dynamic power output; thus they are commonly found in applications where the power demand is relatively constant. The SE is a thermodynamic engine that delivers power by alternatively heating and cooling a fixed volume of gas with work being done by the pressure increase during the heating phase. A number of arrangements for achieving the alternate heating and cooling of the working fluid (i.e. a gas) have been developed, giving rise to three main forms of the engine (alpha, beta and gamma). In these traditional configurations and commercialized arrangements of a SE, the mechanical work is usually produced by the pressure of the heated gas acting on piston-crankshaft arrangements. The heat exchange surface is the surface of the cylinder(s) but mostly the cylinder head(s). Rotating SE's with crankshaft/piston designs require special seals, or provision to regenerate and recharge the working gas as it is lost through the joints provided for lubrication and power transfer.
One aspect of the present disclosure relates to systems for generating electrical power by utilizing heat. Another aspect of the present disclosure relates to methods for generating electrical power by utilizing heat.
This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter. Nor is this Summary intended to be used to limit the claimed subject matter's scope.
Non-limiting and non-exhaustive embodiments are described with reference to the following figures, wherein like reference numerals refer to like parts throughout the various views unless otherwise specified.
Various embodiments are described more fully below with reference to the accompanying drawings, which form a part hereof, and which show specific embodiments of the invention. However, embodiments may be implemented in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Therefore, the following detailed description is not to be taken in a limiting sense.
Conceptually, one embodiment of the present disclosure is a non-cylindrical external combustion engine utilizing the Stirling cycle consisting of a flue (or plurality of flues) through which either the heating (hot combustion gases) or cooling (ambient air or water) fluid passes to respectively heat or cool the appropriate surface of chambers containing a displacer that may be positioned magnetically to expose the working fluid to either the heated or cooled surface.
Turning now to the figures,
Any heat source can be used to power the dual chamber engine 100, particularly since the large heat exchange surface potential allows for efficient function when the temperature differential is low. The heat source may be solar radiation which can be concentrated onto a single side or onto both sides of an engine with the cooling flue being in the center. The heat exchange surface may include structures 136 for increasing surface area available for heat transfer such as fins, bumps, projections, curved surfaces, and other forms of extended surfaces. Moreover, regenerator assemblies may be located on surfaces in the chambers 102 and 104 in the path of displaced working gases to increase heat capture efficiency as the working fluid is moved by the articulated movement of the baffles 106 and 108. The chambers 102, 104, and flue 124 and the baffles 106 and 108 may be constructed from pressed/rolled metal welded at the seams to minimize gas leakage problems.
The chambers 102 and 104 have two opposing sides 126 and 128 that are identified as the heated and cooled surfaces, respectively. The power output of SE's is determined by the temperature difference between the internal heat exchange surfaces, the amount of gas displaced between the heated and cooled chambers, and the frequency of the cycle, the greatest efficiency of energy capture will be provided by a high exchange surface-chamber volume ratio which will maximize the cycle frequency. For instance a square tube of 2×2 cm has half the exchange surface area of a 4×1 cm tube while having the same volume of working gas. Sides 126 are heated by the heating medium and sides 128 are cooled by ambient air or other fluid cooler than the heat source. The simplest configuration would be a rectangular section tube but compound curves and corrugations are possible and may achieve savings of materials in manufacture. The material for construction of the chambers 102 and 104 may be non-magnetic within the vicinity of the magnet displacer drive to allow the action of the external magnets on the internal displacer. For example, the chambers 102 and 104 may be constructed from non-magnetic stainless steel, aluminum, or other materials that do not exhibit ferromagnetic properties such as plastics and ceramics.
The baffles 106 and 108 act as displacers to displace the working fluid in the chambers 102 and 104 thereby determining whether the working fluid is heated or cooled. Note that while
The magnets 110 and 112 may be fixed magnets or electromagnets. In addition, the magnets may be stationary or movable. For example, as shown in
Turning now to
Once the magnet in the linear alternator 114 reaches a certain position, the cycle 200 proceeds to stage 210. In stage 210, the magnets 110 and 112 are repositioned to cause the baffles 106 and 108 to change positions as indicated by arrows 204 and 206. While
Once the baffles 106 and 108 have changed positions, the cycle 200 proceeds to stage 215. In stage 215, the hot exhaust in the exhaust flue 124 will heat the gas in the chamber 102. As the gas in the chamber 102 absorbs heat, it will expand and drive the magnet(s) in the linear alternator in the direction of arrow 208 thereby generating AC electricity.
Once the magnet in the linear alternator 114 reaches a certain position the cycle 200 proceeds to stage 220. In stage, 220 the magnets 110 and 112 are repositioned to cause the baffles 106 and 108 to change positions as indicated by arrows 212 and 214. After the baffles 106 and 108 have changed positions, the cycle 200 proceeds to stage 205 where the cycle 200 begins again.
Note that while
As above with the dual chamber engine 100, the magnet 310 may be a fixed magnet or one or more electromagnets. In addition, the magnets may be stationary or movable. For example, as show in
In various applications, including but not limited to, a solar application, electricity generated could be used for a home while water used for cooling would leave the system heated. This type of system could provide a dual value for homes and industry. In addition, two inline chambers could be utilized with the linear alternator 114 working at the junction.
Turning now to
Once the magnet in the linear alternator 314 reaches a certain position the cycle 400 proceeds to stage 410. In stage, 410 the magnet 310 is repositioned to cause the baffle 306 to change positions as indicated by arrow 404. While
Once the baffle 306 has changed positions, the cycle 400 proceeds to stage 415. In stage 415, the hot exhaust in the heat source 324 will heat the gas in the chamber 302. As the gas in the chamber 302 absorbs waste heat, it will expand and drive the magnet in the linear alternator 314 in the direction of arrow 408 thereby generating AC electricity.
Once the magnet in the linear alternator 314 reaches a certain position the cycle 400 proceeds to stage 420. In stage 420, the magnet 310 is repositioned to cause the baffle 306 to change positions as indicated by arrow 412. After the baffle 306 has changed positions, the cycle 400 proceeds to stage 405 where the cycle 400 begins again.
In other embodiments, movement of the slides in a parallel action may be controlled by electromagnets or magnets on turntables. The turntables may be both above and below the chambers 502 and 504. Also note that there are a variety of displacer configurations. Non-limiting example include a pivoted rectangular displacer inside a V-shaped chamber, and a pie-slice shaped displacer in a rectangular sectioned chamber where the movement is not a pivot but a rocking action.
Note that while
The operation of the dual chamber engine 500 may be described with reference to
Once the magnet in the linear alternator 514 reaches a certain position, the cycle 600 proceeds to stage 610. In stage 610, the electromagnets 510 and 512 de-energize or change polarity and the electromagnets 526 and 528 energize to cause the slides 506 and 508 to change positions as indicated by arrows 604 and 606. In other aspects of the disclosure, positioning of the baffles 106 and 108 may be controlled by sensors. The sensors monitor the pressure of the working fluid, or position of the linear alternator's 514 magnet 534. The sensors may receive power from the linear alternator 514.
Once the slides 506 and 508 have changed positions, the cycle 600 proceeds to stage 615. In stage 615, the hot exhaust in the exhaust conduit 524 will heat the gas in the chamber 502, while the working fluid in chamber 504 looses heat and contracts. As the gas in the chamber 502 absorbs waste heat, it will expand and drive the magnet 534 in the linear alternator 514 in the direction of arrow 608 thereby generating AC electricity.
Once the magnet 534 in the linear alternator 514 reaches a certain position the cycle 600 proceeds to stage 620. In stage, 620 the electromagnets 526 and 528 de-energize and the electromagnets 510 and 512 energize to cause the slides 506 and 508 to change positions as indicated by arrows 612 and 614. After the slides 506 and 508 have changed positions, the cycle 600 proceeds to stage 605 where the cycle 600 begins again.
For example, the cycle 600 begins at stage 605 with the slides 506 and 508 positioned so that as hot exhaust passes through the exhaust conduit 524, heat is transferred from the exhaust to a gas located in the chamber 504. While the exhaust is heating the gas in the chamber 504, the gas in the chamber 502 is being cooled. As the gas in the chamber 504 receives heat from the hot exhaust, working fluid (e.g. air) flow from the chamber being heated to the chamber being cooled causes a magnet located in the linear alternator 514 to move in the direction of arrow 202 and generate electricity.
Once the magnet in the linear alternator 514 reaches a certain position the cycle 600 proceeds to stage 610. In stage 610, the magnets 510 and 512 are deactivated and the magnates 526 and 528 are activated to cause the slides 506 and 508 to change positions as indicated by arrows 604 and 606.
Once the slides 506 and 508 have changed positions, the cycle 600 proceeds to stage 615. In stage 615, the hot exhaust in the exhaust conduit 524 will heat the gas in the chamber 502. As the gas in the chamber 502 absorbs waste heat, it will expand and drive the magnet in the linear alternator 514 in the direction of arrow 608 thereby generating AC electricity.
Once the magnet in the linear alternator 514 reaches a certain position the cycle 600 proceeds to stage 620. In stage 620, the magnets 510 and 512 activate and the magnets 526 and 528 deactivate to cause the slides 506 and 508 to traverse the chambers 502 and 504, respectively, as indicated by arrows 612 and 614. After the slides 506 and 508 have changed positions, the cycle 600 proceeds to stage 605 where the cycle 600 begins again.
Another example of an operating environment may include an exhaust system. For this environment, an array of the dual chamber engines 100 may act as flues with catalytic materials or catalytic cores in the flue 124 to form a power generating catalytic converter for vehicles with internal combustion engines. For example, catalytic materials may include, but are not limited to platinum, palladium, rhodium, cerium, iron, manganese, copper, and nickel. In addition, the use of sound absorbing materials may be attached to spacers (upper side and lower side of 124 (125, and 127) forming the flue 124 of the dual chamber engines 100 to form the exhaust pipe and thus forming a power generating muffler. For example, the dual chamber engine 100 can be incorporated along the length of an exhaust system of an engine (e.g., along exhaust piping such as a tail pipe, catalytic converter housing, diesel particulate filter housing, muffler bodies or other components of an exhaust system). The engine can be a stationary engine or an engine on a vehicle.
In another operating environment, the dual or single chamber engine 100 may be used with solar concentrators. The solar concentrators may concentrate solar energy onto surface 128 to heat the fluids in chambers 102 and 104. A cooling fluid (e.g., water or air) may be used to dissipate heat via surfaces 126.
In addition, multiple chambers may drive a single linear alternator. In other words, the heat exchange surface may be very large so the linear alternator output is maximized. In other embodiments a large heat exchange surface area may allow the system to work with a small temperature differential. In yet other embodiments, a flue with multiple single or dual chamber engines 100 (e.g. a 2×2 chamber) so that all internal surfaces are providing for energy capture.
Reference may be made throughout this specification to “one embodiment,” “an embodiment,” “embodiments,” “an aspect,” or “aspects” meaning that a particular described feature, structure, or characteristic may be included in at least one embodiment of the present invention. Thus, usage of such phrases may refer to more than just one embodiment or aspect. In addition, the described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments or aspects. Furthermore, reference to a single item may mean a single item or a plurality of items, just as reference to a plurality of items may mean a single item. Moreover, use of the term “and” when incorporated into a list is intended to imply that all the elements of the list, a single item of the list, or any combination of items in the list has been contemplated.
One skilled in the relevant art may recognize, however, that the invention may be practiced without one or more of the specific details, or with other methods, resources, materials, etc. In other instances, well known structures, resources, or operations have not been shown or described in detail merely to avoid obscuring aspects of the invention.
While example embodiments and applications of the present invention have been illustrated and described, it is to be understood that the invention is not limited to the precise configuration and resources described above. Various modifications, changes, and variations apparent to those skilled in the art may be made in the arrangement, operation, and details of the methods and systems of the present invention disclosed herein without departing from the scope of the claimed invention.
The above specification, examples, and data provide a description of the manufacture, operation and use of the invention. Since many embodiments of the invention can be made without departing from the spirit and scope of the invention, the invention resides in the claims hereinafter appended.
