WO1996008388A1

WO1996008388A1 - Automotive vehicle power system

Info

Publication number: WO1996008388A1
Application number: PCT/US1995/012112
Authority: WO
Inventors: Ralph H. Lewis
Original assignee: Lewis Ralph H
Priority date: 1994-09-14
Filing date: 1995-09-13
Publication date: 1996-03-21
Also published as: AU3722595A

Abstract

A pollution free automotive vehicle (150) includes an automotive power system (10) that converts stored thermal energy into electricity for energizing electric vehicle drive-motors (112). A heat engine (92), preferably a closed cycle turbine (34), converts thermal energy stored in a preferably solid thermal-energy-storage material (14) into rotation of a turbine shaft (38). Rotation of the turbine shaft (13) drives an alternator (42) to generate electricity. A radiator (62), structurally integrated into the automotive vehicle's chassis (152), radiates thermal energy from a preferably inert working fluid (16) into the atmosphere surrounding the vehicle (150). Several different methods are disclosed for reheating the thermal-energy-storage material (14).

Description

AUTOMOTIVE VEHICLE POWER SYSTEM Technical Field

The present invention relates generally to the technical field of automotive power systems, and, more particularly, to an automotive power system that converts stored thermal energy into electricity for energizing a vehicle's electric driving motors.

Background Art

Present and anticipated air pollution restrictions indicate that emission free vehicles will be operating in major urban areas in the foreseeable future. Presently, electricity appears to be the only possible power source for an emission free vehicle. A significant difficulty presently encountered by proposed electric vehicles is that they employ batteries which currently have an unsatisfactorily low energy density. The energy density of presently available batteries is so low that a battery powered vehicle designed to travel 400 miles between battery recharges can carry nothing other than the batteries which power its operation. Consequently, producing a useful battery powered vehicle with a 400 mile cruising range requires a major breakthrough in battery technology.

For scores of years in various industrial settings, steam powered locomotives have operated which lack any ability for heating water to make steam. Rather, such locomotives are powered by stored thermal energy. The power source carried by these locomotives is a heavily insulated water tank which is periodically filled with superheated water. This superheated water provides the locomotive's power source. The energy density of such superheated water is so great that it is superior to that of present electrical batteries.

Employing hot water as a thermal-energy-storage material, United States Patent no. 5,385,214 which issued January 31, 1995 on an application filed by John E. Spurgeon ("the Spurgeon patent") , discloses a motor vehicle having a "heat battery" which supplies high-pressure steam to a closed cycle, conventional heat engine that includes a steam turbine. The Spurgeon patent expressly discloses that the heat battery stores hot water at a temperature of 374 degrees centigrade ("°C"), i.e. 705 degrees Fahrenheit ("°F") , and at a pressure of 221 bar, i.e. 3205 pounds per square inch ("PSI") . The Spurgeon patent employs hot water at this particular temperature and pressure because under those conditions the material's heat capacity appears to be infinite. In the closed cycle disclosed in the Spurgeon patent, thermal energy stored in the heat battery boils water that drives a conventional steam turbine and returns to the heat battery after passing through a condenser. The Spurgeon patent discloses that the condenser is to be located at the front of the vehicle replacing a conventional automotive radiator.

A technical paper entitled "The Thermal Vehicle - A Pollution Free Concept" by Jack R. Kettler presented at the "Tenth Intersociety Energy Conversion Engineering Conference held August 18-22, 1975 ("the Kettler paper"), compares thermal and electric vehicles, emphasizing system design performance. The Kettler paper also compares alternative types of heat engines and thermal-storage materials. The Kettler paper reports that most automotive gas-turbine-engine studies have dealt with internal- combustion gas turbines. It comments that these studies are not pertinent to the thermal vehicle since they used a 1900°F turbine inlet temperature, which would be too high for a gas turbine if its working fluid were to be heated by an external source. The Kettler paper further reports that a closed-cycle gas turbine operating with external combustion had been designed with a turbine inlet temperature of 1500°F.

The Garrett Fluid Systems Division of Allied-Signal Aerospace Company has developed a closed Brayton cycle turbine which is capable of continuously converting stored thermal energy into 30 KW of electrical power, an amount of power sufficient to power an automobile. More specifically, this turbine employs solid, ceramic material as a thermal-energy-storage material. To energize the turbine, a vessel containing the hot ceramic material heats an inert gas working fluid, such as argon or nitrogen, which then passes through the turbine. An alternator coupled to a shaft rotated by the turbine generates electricity. Upon being exhausted from the turbine, the inert gas working fluid passes first through a recuperator and then through a water cooled cooler, both of which cool the inert gas working fluid. The cooled inert gas then passes through a compressor that is also driven by the turbine's shaft before returning to the recuperator in which the inert gas begins being reheated. After the inert gas leaves the recuperator, it then returns to the vessel of hot ceramic material for additional heating before returning once again to the turbine.

A technical paper entitled "Power From Thermal Energy Storage Systems" by Worth H. Percival and Michael Tsou presented at the Society of Automotive Engineers Combined National Fuels and Lubricants, Powerplant and Transportation Meetings, October 29 through November 1, 1962, (the Percival paper"), reports various proposals that have been made for using stored thermal energy. For example the Percival paper reports a proposal for electrically heating crushed stone during off-load hours, and then subsequently using the stored heat for space heating when electrical power system load is high. The Percival paper also reports that heat stored in refractory pebbles or spheres at temperatures as high as 3000°F has been used for brief intervals in heating air or other gases to a high temperature in high-speed wind tunnels. In considering various alternatives for converting stored heat into mechanical energy, the Percival paper states that, in comparison with the Stirling engine's efficiency of approximately 40%, it is questionable whether a Brayton-cycle gas turbine will ever reach an efficiency of 40%. The Percival paper states unequivocally that the Brayton-cycle gas turbine "can not hope to compete on the basis of total integrated work available from [a thermal energy] storage tank compared to the Rankine cycle steam cycle or Stirling engine." The Percival paper also states that in converting stored thermal energy into mechanical energy, a closed-Brayton-cycle turbine achieves higher efficiency than an open-Brayton-cycle turbine.

A problem that is common to all closed cycle power systems is a need to cool the working fluid after hot working fluid has been expanded to extract mechanical energy, e.g. the rotation of a shaft. However, cooling working fluid for an automotive closed cycle power system is more demanding than for a stationary closed cycle power system. Generally, cooling the working fluid of a closed cycle automotive power system requires using a condenser or radiator which must dissipate more energy than a conventional automotive radiator, and which may be required to operate at a working fluid pressure many times higher than that of a conven¬ tional automotive radiator. To accommodate these requirements, the size and weight of a condenser or radiator for a closed cycie automotive vehicle may impose sever limitations on the design of such an automotive vehicle

Disclosure of Invention An object of the present invention is to provide a pollution free automotive vehicle capable of carrying a practical load for a distance of 400 miles.

Another object of the present invention is to provide a pollution free automotive vehicle energized by a closed cycle power system having a radiator/condenser that alleviates limitations on such a vehicle's design.

Another object of the present invention is to provide a pollution free automotive vehicle which can be refueled quickly.

Another object of the present invention is to provide a pollution free automotive vehicle having performance comparable to present vehicles powered by internal combustion engines.

Another object of the present invention is to provide a pollution free automotive vehicle which employs existing energy sources more efficiently. Another object of the present invention is to provide a pollution free automotive vehicle which can be assembled using existing technologies.

Yet another object of the present invention is to provide a pollution free automotive vehicle whose construction requires only plentiful and readily available raw materials.

Another object of the present invention is to provide an apparatus and method for quickly refueling a pollution free automotive vehicle.

Briefly, one aspect of the present invention is an automo- tive vehicle powered by stored thermal energy. The automotive vehicle includes a working-fluid heating vessel which initially contains a quantity of hot thermal-energy-storage material. A working fluid passes through the working-fluid heating vessel to be heated by a flow of thermal energy within the working-fluid heating vessel from the thermal-energy-storage material to the working fluid. The flow of thermal energy also cools the thermal-energy-storage material. To regenerate the heat carried by the thermal-energy-storage material, the working-fluid heating vessel further includes thermal-energy regeneration means.

The automotive vehicle also includes a heat engine for receiving from the working-fluid heating vessel a flow of hot working fluid. The flow of hot working fluid passing through the heat engine and induces rotation of a heat engine output shaft. The heat engine disclosed herein is preferably a closed Brayton cycle turbine.

To convert the rotation of the heat engine output shaft into electricity, the automotive vehicle includes an alternator having a fixed stator and a moveable rotor. The moveable rotor is coupled to an alternator shaft that, in turn, is coupled to the heat engine output shaft. Rotation of the rotor causes the alternator to generate an electrical potential across a pair of alternator power output terminals which supply an electric current to an external electrical load.

To conserve weight, the automotive vehicle includes working-fluid radiator that is structurally integrated into the vehicle's chassis. Specifically, the chassis of an automotive vehicle in accordance with the present invention includes a corrugated panel formed along the lower surface of the chassis nearest the ground. This corrugated panel includes alternating air passages and working-fluid passages thereby providing an axial flow radiator for the working fluid. The radiator receives a flow of the working fluid from the heat engine and discharges the flow of the working fluid back to the heat engine. Air in the atmosphere surrounding the automotive vehicle flows through the air passages in the chassis/radiator to absorb thermal energy radiated by the working fluid in the immediately adjacent working fluid passages. Radiation of thermal energy from the working-fluid radiator to atmosphere surrounding the radiator cools the flow of working fluid passing through the radiator.

An electronic control is electrically coupled between the power output terminals of the alternator and an electric drive motor. The electronic control receives an electric current from the power output terminals and supplies a controlled electric current to the electric drive motor. The electric drive motor is adapted to be coupled to a wheel of the automotive vehicle for energizing the wheel's rotation.

Another aspect of the present invention is a thermal-energy regeneration station adapted for reheating the thermal-energy- storage material contained in an automotive vehicle's working- fluid heating-vessel. The thermal-energy regeneration station includes a nozzle adapted for mating with and engaging the working-fluid exchange port of the vessel containing the thermal- energy-storage material. A pump coupled to the nozzle and to a hollow furnace tube circulates a flow of hot working fluid through the working-fluid heating-vessel. A means for heating the hollow furnace tube preferably includes a burner which burns a mixture of air and natural gas. A regeneration control, preferably included in the regeneration station, determines a price for thermal energy transferred from the thermal-energy regeneration station to the thermal-energy-storage material in the automotive vehicle.

These and other features, objects and advantages will be understood or apparent to those of ordinary skill in the art from the following detailed description of the preferred embodiment as illustrated in the various drawing figures.

Brief Description of Drawings

FIG. 1 is a functional block diagram depicting an automotive vehicle in accordance with the present invention that includes a working-fluid heating-vessel which contains a quantity of hot, thermal-energy-storage material for heating a working fluid, and that includes a radiator for cooling the working fluid;

FIG. 2 is a perspective view of the chassis of an automotive vehicle which depicts the radiator, depicted in FIG. 1, that is structurally integrated into the automotive vehicle's chassis; FIG. 3 is a cross-sectional elevational view of the radiator taken along the line 3-3 in FIG. 2 that is integrated into the automotive vehicle's chassis; FIG. 4 is a partially sectioned plan view of a working-fluid heating-vessel that contains a quantity of thermal-energy-storage material;

FIG. 5 is a perspective view depicting both wheels of an automotive vehicle positioned at a thermal-energy-regeneration station and nozzles included in the thermal-energy-regeneration station that automatically engages a working-fluid exchange port included in the working-fluid heating-vessel depicted in FIG. 1; and FIG. 6 is a cut-away elevational view depicting thermal- energy-regeneration station which supplies hot working fluid for reheating the thermal-energy-storage material contained in the working-fluid heating-vessel depicted in FIG. 1.

Best Mode for Carrying Out the Invention Automotive vehicle

FIG. 1 is a block diagram illustrating a power system for an automotive vehicle, referred to by the general reference character 10, that is powered by stored thermal energy. The automotive power system 10 includes a working-fluid heating-vessel 12. The working-fluid heating-vessel 12 initially contains a quantity of hot, solid thermal-energy-storage material ("TESM") , which may be selected from ceramic materials such as silicon, boron carbide, alumina, aluminum carbide, or beryllium oxide. During operation of the automotive power system 10, a flow of a working fluid 16, which is preferably an inert nobel gas such as argon or alternatively nitrogen, passes through the working-fluid heating-vessel 12. Consequently, the working-fluid heating-vessel 12 includes a working-fluid heating-vessel inlet 22 and a working-fluid heating-vessel outlet 24. The working-fluid heating-vessel inlet 22 receives a flow of working fluid 16 from a heat-regenerator cool-working-fluid outlet 26 of a heat regenerator 28. The working-fluid heating-vessel inlet 22 receives the working fluid 16 at a first heating-vessel inlet- temperature of between 950 to 1050 degrees Fahrenheit ("OF") , and at a first working-fluid heating-vessel inlet pressure between 70 and 85 pounds per square inch ("PSI"). Within the working-fluid heating-vessel 12, a flow of thermal energy from the TESM 14 to the working fluid 16 heats the working fluid 16 to a temperature of between 1450 and 1500 °F at which temperature it is discharged from the working-fluid heating-vessel outlet 24 at a working-fluid heating-vessel outlet pressure between 70 and 80 PSI.

The working fluid 16 discharged from the working-fluid heating-vessel outlet 24 enters a working-fluid turbine-inlet 32 of a working-fluid turbine 34. The working-fluid turbine 34 discharges the flow of the working fluid 16 received at the working-fluid turbine-inlet 32 from a working-fluid turbine-outlet 36. The flow of working fluid 16 passing through the working-fluid turbine 34 induces rotation of a turbine shaft 38 included in the working-fluid turbine 34.

The automotive power system 10 also includes a thirty (30) kilowatt ("KW") conventional alternator 42. As is well known in the art, the alternator 42 includes a fixed stator and a moveable rotor, neither of which are separately illustrated in any of the FIGs. The alternator 42 also includes an alternator shaft 44, which is coupled to the turbine shaft 38, on which is mounted the rotor of the alternator 42. Consequently, rotation of the turbine shaft 38 causes rotation of the rotor included in the alternator 42. The alternator 42 also includes a pair of alternator power-output-terminals 46 for supplying an electric current to an electrical load which is external to the alternator 42. Rotation of the rotor included in the alternator 42 in response to a flow of the working fluid 16 passing through the working-fluid turbine 34 generates an electrical potential across the pair of alternator power-output-terminals 46.

The heat regenerator 28 also includes a heat-regenerator hot-working-fluid inlet 54 which receives a flow of hot working fluid 16 exhausted from the working-fluid turbine-outlet 36 of the working-fluid turbine 34. For the preferred working fluid 16, the heat-regenerator hot-working-fluid inlet 54 receives the working fluid 16 at a heat-regenerator hot-working-fluid inlet- temperature between 370 and 420 °F, and at a heat-regenerator hot-working-fluid inlet pressure of approximately 35 to 45 PSI. The heat regenerator 28 also includes a heat-regenerator hot-working-fluid outlet 56 for discharging, at a heat-regenera- tor hot-working-fluid outlet-temperature between 270 and 290 OF and at a heat-regenerator hot-working-fluid outlet pressure of approximately 70 to 80 PSI, the flow of hot working fluid 16 received at the heat-regenerator hot-working-fluid inlet 54. The automotive power system 10 also includes a working-fluid radiator 62 which has a radiator working-fluid inlet 64. The radiator working-fluid inlet 64 receives, via the heat regenera¬ tor 28, a flow of the working fluid 16 exhausted from the working-fluid turbine-outlet 36 of the working-fluid turbine 34. For the preferred working fluid 16, the radiator working-fluid inlet 64 receives the working fluid 16 at a radiator inlet- temperature between 420 to 450 OF, and at a radiator inlet pressure of approximately 70 and 80 PSI. The working-fluid radiator 62 also includes a radiator working-fluid outlet 66 for discharging the flow of working fluid 16 received at the radiator working-fluid inlet 64 at a radiator outlet-temperature of approximately 90 ©F. The automotive power system 10 preferably includes a fan 68 for blowing air through the working-fluid radiator 62. Accordingly, working fluid 16 flowing through the working-fluid radiator 62 radiates thermal energy into the atmosphere surrounding the automotive power system 10 thereby cooling the working fluid 16.

The automotive power system 10 also includes a working-fluid compressor 72 having a working-fluid compressor-inlet 74 and a working-fluid compressor-outlet 76. Theworking-fluid compressor 72 also includes a compressor shaft 78 which is coupled, via the alternator shaft 44, to the turbine shaft 38. Thus, rotation of the turbine shaft 38 responsive to the flow of working fluid 16 through the working-fluid turbine 34 rotates the compressor shaft 78. Rotation of the compressor shaft 78 causes the working-fluid compressor 72 to draw a flow of working fluid 16 from the radiator working-fluid outlet 66 of the working-fluid radiator 62 at a compressor inlet pressure of 30 to 40 PSI. The working-fluid compressor 72 discharges the flow of the working fluid 16 from the working-fluid compressor-outlet 76 to a heat-regenerator cool-working-fluid inlet 82 of the heat regenerator 28 at a compressor outlet pressure of 65 to 75 PSI. Within the heat regenerator 28, the flow of cool working fluid 16 passes from the heat-regenerator cool-working-fluid inlet 82 to the heat-regenerator cool-working-fluid outlet 26 to re-enter the working-fluid heating-vessel 12 via the working-fluid heating-vessel inlet 22. The combined working-fluid turbine 34 and working-fluid compressor 72 constitute a heat engine 92, illustrated in FIG. 2, for converting thermal energy stored in the working-fluid heating-vessel 12 into mechanical energy. While a heat engine with a closed working fluid cycle, i.e. a Brayton cycle turbine, is disclosed herein, automotive vehicles incorporating alterna¬ tive types of heat engines, such as a Stirling engine or even an open cycle heat engine, may also be employed in the present invention.

While the heat regenerator 28 has a structure which prevents the hot flow of working fluid 16 from mixing with the cool flow of working fluid 16, the heat regenerator 28 does conduct a flow of thermal energy between the two flows of the working fluid 16. Consequently, the heat-regenerator hot-working-fluid inlet 54 receives a flow of working fluid 16 at a heat-regenerator hot- working-fluid inlet-temperature between 1130 and 1140 OF, the heat-regenerator hot-working-fluid outlet 56 discharges the flow of the working fluid 16 at a heat-regenerator hot-working-fluid outlet-temperature between 410 and 430 F. The heat-regenerator cool-working-fluid inlet 82 of the heat regenerator 28 receives a flow of the working fluid 16 at a heat-regenerator cool- working-fluid inlet-temperature of approximately 280 OF, and at a heat-regenerator cool fluid inlet pressure between 70 to 75 PSI. The heat-regenerator cool-working-fluid outlet 26 of the heat regenerator 28 discharges the cool flow of the working fluid 16 at a heat-regenerator cool-working-fluid outlet-temperature between 950 and 1000 OF, and a heat-regenerator cool-working- fluid outlet pressure between 30 to 65 PSI.

The heat regenerator 28 is preferably of a type disclosed in United States Patent No. 5,259,444 entitled "Heat Exchanger Containing a Component Capable of Discontinuous Movement" that issued November 9, 1993, on an application filed by David G. Wilson ("the '444 Patent"). The '444 Patent is hereby incorpo¬ rated herein by reference. The automotive power system 10 also includes an electronic control 102 which receives an electric current from the alterna¬ tor power-output-terminals 46 of the alternator 42 via alternator power-cables 104. Via a power bus 106, the electronic control 102 distributes the electrical power generated by the alternator 42 to four (4) electric drive-motors 112. Each of the electric drive-motors 112, which preferably are an axial gap motor, is respectively coupled to a wheel of an automotive vehicle, not illustrated in FIG. 1. In addition to distributing electrical power to each of the electric drive-motors 112, the electronic control 102 also distributes, via an electric-drive control-signal bus 114, electrical control signals to control modules 116 included in each of the electric drive-motors 112. The electronic control 102 generates the control signals distrib- uted to the control modules 116 in response to electronic vehicle motion control signals received from various transducers including a direction transducer 122, a speed transducer 124, and a brake transducer 126. Each of the transducers 122, 124 and 126 are individually coupled to the electronic control 102 by vehicle-motion control-signal lines 128. The electronic control 102 also supplies electrical energy to the fan 68 via a fan power-cable 132 and a fan thermostatic-switch 134.

The automotive power system 10 also includes a battery 136 that is coupled to the electronic control 102 by battery cables 138. The battery 136 supplies electrical energy only for starting the vehicle, and for powering accessories when the heat engine 92 is not operating.

As described thus far, the electronic control 102 is conventional. That is, in principle the electronic control 102 might be that of a conventional electrically powered automotive vehicle such as one in which the source of electrical power is a battery. To permit long distance travel, the automotive power system 10 in accordance with the present invention implements energy conservation strategies. Accordingly, while the automo- tive vehicle decelerates or coasts downhill without supplying any power to the electric drive-motors 112, the electronic control 102 causes the electric drive-motors 112 to generate, rather than consume, electrical energy. Under such circumstances, the electronic control 102 supplies electrical energy generated by the electric drive-motors 112 via a heating-vessel power-cable 142 to a working-fluid heating-vessel heater 144 included in the working-fluid heating-vessel 12. Electrical energy supplied to the working-fluid heating-vessel heater 144 heats the TESM 14 contained in the working-fluid heating-vessel 12 thereby partially regenerating the stored thermal energy.

Referring now to FIG. 2, an automotive vehicle in accordance with the present invention, referred to by the general reference character 150, includes chassis 152 upon which are mounted various components included in the vehicle. Accordingly, wheels 154 are secured to the chassis 152 together with drive shafts 156 and reduction ring-gears 158 for coupling the electric drive-motors 112 to the wheels 154. Mechanical brakes 162 secured to the chassis 152 are coupled to the drive shafts 156. Also supported upon the chassis 152 is a conventional steering wheel 164 which is coupled to a conventional steering mechanism 166. In the illustration of FIG. 3, the heat engine 92 together with the alternator 42 are located between the wheels 154 at the front of the automotive vehicle 150.

FIG. 3 depicts a cross-section of the chassis 152, taken along the line 3-3 of FIG. 2, which illustrates structural integration of the working-fluid radiator 62 into the chassis 152. Specifically, the chassis 152 of automotive power system 10 includes a corrugated panel 168 formed along a lower surface 172 of the chassis 152 nearest the ground. The corrugated panel 168 includes alternating air passages 174 and working-fluid passages 176 which are separated from each other by webs 178 of sheet metal. Supported on top of the alternating air passages 174 and working-fluid passages 176 is a layer 182 of insulation, depicted only in FIG. 3, which forms a floor 184 of the interior of the automotive vehicle 150, and which obstructs a transfer of heat from the working-fluid radiator 62 to the interior of the automotive vehicle 150. Thus the chassis 152 provides an axial flow working-fluid radiator 62 for the working fluid 16. Air in the atmosphere surrounding the automotive power system 10 flows through the air passages 174 in the chassis 152 to absorb thermal energy radiated by the working fluid 16 in the immediately adjacent working-fluid passages 176. Radiation of thermal energy from the working fluid 16 to the atmosphere surrounding the automotive power system 10 cools the working fluid 16. Structur¬ al integration of the working-fluid radiator 62 into the chassis 152 reduces the weight of the automotive vehicle 150, while concurrently providing a working-fluid radiator 62 that is capable both of dissipating more energy than a conventionally located automotive radiator, and of operating at a working fluid pressure many times higher than that of a conventional automotive radiator.

Referring now to FIG. 4, the working-fluid heating-vessel 12 includes an insulated outer housing 192 which encloses the TESM 14. The ceramic TESM 14 is arranged to provide a porous structure having a plurality of passages 194 through which the working fluid 16 flows. To permit reheating the TESM 14 using electrical energy generated by regenerative braking, the working-fluid heating-vessel 12 includes the working-fluid heating-vessel heater 144 by which electrical energy electrically heats the TESM 14. A presently preferred form for the TESM 14, illustrated in FIG. 4, is that of sealed, beryllium-oxide tubes 196 which remain solid at a temperature in excess of 2800°F. Such ceramic tubes 196 are filled with silicon, or some other suitable material, which melts at a temperature between 2000 and 2800°F. As is readily apparent to those knowledgeable about energy release or absorption occurring during a material's phase change between a solid and a liquid, solidification of an appropriately selected material releases a significant amount of thermal energy. Accordingly, storing thermal energy in an appropriately selected TESM 14 which melts at a temperature which is in the operating temperature range of the TESM 14 signifi¬ cantly increases the amount of energy which the working-fluid heating-vessel 12 may store for release to the working fluid 16. In addition to regenerating the thermal energy stored in the TESM 14 with electrical energy produced by the electric drive-motors 112, the thermal energy stored in the TESM 14 may also be regenerated by electrical energy produced externally from the automotive power system 10. Accordingly, the electronic control 102 of a stationary automotive vehicle 150 incorporating the automotive power system 10 may receive electrical energy from a source, which is not depicted any of the FIGs., that is external to the automotive power system 10, e.g. electrical energy drawn from an electric power utility. As with electrical energy produced by the automotive power system 10, electrical energy produced externally to the automotive power system 10 is supplied to the working-fluid heating-vessel heater 144 for regenerating the thermal energy stored in the TESM 14.

The automotive power system 10 of the present invention preferably includes a first thermal-regeneration control valve ("FTRCV") 202 disposed immediately adjacent to the working-fluid heating-vessel outlet 24 between the working-fluid heating-vessel outlet 24 and the working-fluid turbine-inlet 32. Oriented in the position illustrated in FIG. 4, the FTRCV 202 permits hot working fluid 16 to flow unimpeded from the working-fluid heating-vessel outlet 24 into the working-fluid turbine-inlet 32. The working-fluid heating-vessel inlet 22 of the working-fluid heating-vessel 12 is coupled through a second thermal-regenera¬ tion control valve ("STRCV") 204, to the heat-regenerator cool-working-fluid outlet 26. Oriented in the position illus¬ trated in FIG. 4, the STRCV 204 permits working fluid 16 to flow unimpeded from the heat-regenerator cool-working-fluid outlet 26 into the working-fluid heating-vessel 12.

If an automotive vehicle 150 incorporating the automotive power system 10 operates so that regenerative braking supplies electrical energy to the TESM 14, an automatically controlled bypass valve 208, depicted in FIG. 1, opens to divert around the working-fluid heating-vessel 12 the working fluid 16 flowing from the heat regenerator 28 to the working-fluid turbine 34. Because the bypass valve 208 provides an alternative path by which the working fluid 16 may flow from the heat-regenerator cool-working-fluid outlet 26 of the heat regenerator 28 to the working-fluid turbine-inlet 32 of the working-fluid turbine 34, during normal operation of the automotive power system 10 in an automotive vehicle 150, the bypass valve 208 opens and closes in response to the power load placed on the automotive power system 10 so the working fluid 16 flows into the working-fluid turbine 34 at a constant temperature. Swift Regeneration of Thermal-Energγ-Storage Material

To facilitate swift regeneration of thermal energy stored in the TESM 14, the working-fluid heating-vessel 12 also includes a thermal-energy-regeneration inlet-port 212 that is coupled to the FTRCV 202, and a thermal-energy-regeneration outlet-port 214 that is coupled to the STRCV 204. Appropriately orienting the

FTRCV 202 and the STRCV 204 permits a flow of working fluid 16 entering the working-fluid heating-vessel 12 through the thermal-energy-regeneration inlet-port 212 to circulate through the TESM 14 within the working-fluid heating-vessel 12, and then leave the working-fluid heating-vessel 12 via the thermal-energy-regeneration outlet-port 214. Such a flow of hot working fluid 16 may be employed for regenerating the thermal energy stored in the TESM 14.

FIG. 5 depicts a cutaway perspective view of a portion of an automotive vehicle 150 positioned adjacent to a thermal-energy-regeneration station 224, illustrated more comprehensively in the block diagram of FIG 5. The illustration of FIG. 5 depicts wheels 154, drive shafts 156, brakes 162, electric drive-motors 112, a portion of a chassis 152 of the automotive vehicle 150, and a partially cut-away view of the working-fluid heating-vessel 12. FIG.5 specifically illustrates an automated coupling 226 which unites the thermal-energy-regeneration station 224 with the automotive vehicle 150 during regeneration of the TESM 14.

Before commencing regeneration of the TESM 14, the automated coupling 226 is located beneath ground level and blocked by a cover plate 228. One of the wheels 154 of the automotive vehicle 150 is then positioned into a depressed trough 232 of a fixed vehicle-positioning plate 234. Disposing the wheel 154 in the trough 232 fixes the location of the automotive vehicle 150 with respect to the automated coupling 226. After the wheel 154 has been positioned in the trough 232, the cover plate 228 automati- cally opens and the automated coupling 226 rises out of the ground toward the working-fluid heating-vessel 12 that is located directly above. The automated coupling 226 includes a hot-working-fluid supply-nozzle 236 and a hot-working-fluid suction-nozzle 238. The hot-working-fluid supply-nozzle 236 and the hot-working-fluid suction-nozzle 238 provide conduits by which hot working fluid 16 flows through the working-fluid heating-vessel 12 immediately after the automated coupling 226 extends sufficiently far above ground level to mate the lines 236 and 238 with the corresponding thermal-energy-regeneration inlet-port 212 and thermal-energy-regeneration outlet-port 214 of the working-fluid heating-vessel 12 that are illustrated in FIGs. l and 4. After the TESM 14 has been regenerated, the flows of hot working fluid 16 is terminated, the automated coupling 226 retracts away from the automotive vehicle 150 to return to a subterranean position, and the cover plate 228 returns to a position blocking the automated coupling 226.

FIG. 6 illustrates a thermal-energy-regeneration station, referred to by the general reference character 224, that is adapted for quickly regenerating the thermal energy stored in the TESM 14 using a flow of hot working fluid 16. The thermal-energy-regeneration station 224 basically consists of a specially adapted furnace 242 that includes a heat exchanger 244. The furnace 242 draws air 246, indicated by arrows in FIG. 6, from atmosphere surrounding the furnace 242 into the heat exchanger 244 through an air inlet 248. The air 246 flowing through the heat exchanger 244 is partially heated to a tempera¬ ture of approximately 2500°F in a manner to be described more comprehensively hereinbelow. The working fluid 16 then flows from the heat exchanger 244 into a fire box 252 wherein the air 246 is further heated. To heat the air 246 within the fire box 252, the furnace 242 receives a flow of a combustible fuel 254, preferably natural gas or propane, which burns within a burner 256 located within the fire box 252. Upon leaving the fire box 252, after flowing past the burner 256, the air 246 is heated to a temperature greater than 2800°F, preferably 3500-4000°F. The hot air 246 from the fire box 252 then flows through aworking-fluid heating-conduit 262 to a combustion-gas inlet 264 to the heat exchanger 244. While passing through the heat exchanger 244 from the combustion-gas inlet 264 to an exhaust 266, the hot air 246 heats the air 246 entering the heat exchanger 244 through the air inlet 248. In addition to conducting a flow of hot air 246 from the fire box 252 to the combustion-gas inlet 264, the working-fluid heating-conduit 262 also encloses a hollow ceramic furnace tube 272. An inlet 274 to the furnace tube 272 is coupled to a working-fluid pump 276 which draws working fluid 16 from the working-fluid heating-vessel 12 of the automotive vehicle 150 through the hot-working-fluid suction-nozzle 238. The working fluid 16 flowing into the inlet 274 passes through the furnace tube 272 to a outlet 278 of the furnace tube 272. The working fluid 16 then flows from the outlet 278 back to the working-fluid heating-vessel 12 of the automotive vehicle 150 through the hot-working-fluid supply-nozzle 236. Within the working-fluid heating-vessel 12, the hot working fluid 16 flows from the FTRCV 202 past the TESM 14 to the STRCV 204 to regenerate the heat stored in the TESM 14.

The thermal-energy-regeneration station 224 also includes a working-fluid storage-tank 282 which contains a reserve of working fluid 16, e.g. inert gas. Upon commencing regeneration of the TESM 14 contained in a working-fluid heating-vessel 12, a regeneration control 284, included in the thermal-energy-regeneration station 224, activates an outlet valve 286 on the working-fluid storage-tank 282 to supply working fluid 16 to the furnace tube 272. The supply of working fluid 16 from the working-fluid storage-tank 282 to the furnace tube 272 pressurizes both the hot-working-fluid supply-nozzle 236 and its mating thermal-energy-regeneration inlet-port 212, and the thermal-energy-regeneration outlet-port 214 and its mating hot-working-fluid suction-nozzle 238. In this way any losses of working fluid 16 which occur during regeneration of the TESM 14 may be made up, and air in the atmosphere surrounding the thermal-energy-regeneration station 224 and the automotive vehicle 150 cannot enter into the working-fluid heating-vessel 12. In this way the automotive vehicle 150 employing the automotive power system 10 may be "re-fueled" in a matter of min- utes, at which time the automotive vehicle 150 may immediately resume traveling.

The thermal-energy-regeneration station 224 includes a vehicle sensor 292 which supplies an electronic signal to the regeneration control 284 when a automotive vehicle 150 arrives for regeneration. The vehicle sensor 292 may include a credit card reader so the regeneration control 284 may automatically charge for the amount of energy deposited in the TESM 14 in a automotive vehicle 150. By measuring both the temperature of the working fluid 16 entering the working-fluid heating-vessel 12 of the automotive vehicle 150 via the hot-working-fluid supply-nozzle 236 and the temperature of the working fluid 16 returning to the thermal-energy-regeneration station 224 through the hot-working-fluid suction-nozzle 238, and the rate at which the working-fluid pump 276 draws working fluid 16 from the working-fluid heating-vessel 12, the thermal-energy-regeneration station 224 may both monitor the regeneration state of the TESM 14, and measure the quantity of energy required to regenerate the TESM 14. By monitoring the quantity of energy required to regenerate the TESM 14, the thermal-energy-regeneration station 224 can determine an appropriate price for the quantity of energy stored into the TESM 14.

Operating in the preceding manner, the hot working fluid method for regenerating the thermal energy stored in the TESM 14 operates at an overall efficiency of approximately 92%. This efficiency for regeneration of the thermal energy stored in the results in an overall efficiency of approximately 90 to 94%. Correspondingly, a automotive vehicle 150 incorporating the automotive power system 10 disclosed herein operates an overall efficiency of 48 to 52% in converting energy in the combustible fuel 254 into driving energy for the vehicle's wheels. This energy efficiency for a automotive vehicle 150 powered by the automotive power system 10 compares favorably with the energy efficiency of a conventional motor vehicles powered by a standard internal-combustion engines which presently demonstrate a comparable energy efficiency of approximately 14-28%.

Industrial Applicability As used in the present invention, the term wheels includes, in addition to conventional tires such as those used on cars and trucks, sprocketed wheels such as those used for driving tracks of tracked vehicles such as tractors and tanks. In addition to being used to power land vehicles, the automotive power system 10 disclosed herein can power the operation of marine vehicles such as boats, submersibles and torpedoes.

Although the present invention has been described in terms of the presently preferred embodiment, it is to be understood that such disclosure is purely illustrative and is not to be interpreted as limiting. For example, the working-fluid pump 276 may be located between the outlet 278 and the hot-working-fluid supply-nozzle 236 rather than between the hot-working-fluid suction-nozzle 238 and the inlet 274. Similarly, while the working-fluid radiator 62 has been disclosed as only cooling the working fluid 16 exhausted from the working-fluid turbine 34 of the heat engine 92, depending upon precise details of the design of the heat engine 92 the working-fluid radiator 62 may be used, either partially or wholly, for radiating heat from the working fluid 16 at other locations within the heat engine 92. For example, if the heat engine 92 employs a multi-stage working-fluid compressor 72, then the working-fluid radiator 62 may be used to provide an intercooler for cooling the working fluid 16 between stages of the multi-stage working-fluid compressor 72. Furthermore, in addition to natural gas or propane, the heat source for regenerating the TESM 14 may be any combustible material including a hydrocarbon, carbon, hydrogen, agricultural or industrial waste, or biomass fuel, or may even be solar or geothermal energy. Consequently, without departing from the spirit and scope of the invention, various alterations, modifications, and/or alternative applications of the invention will, no doubt, be suggested to those skilled in the art after having read the preceding disclosure. Accordingly, it is intended that the following claims be interpreted as encompassing all alterations, modifications, or alternative applications as fall within the true spirit and scope of the invention.

Claims

The ClaimsWhat is claimed is:

1. An automotive vehicle powered by stored thermal energy comprising: a working-fluid heating-vessel which initially contains a quantity of hot thermal-energy-storage material, and which also permits a flow of a working fluid to pass through said working-fluid heating-vessel, a flow of thermal energy within saidworking-fluidheating-vessel fromthe thermal-energy-storage material to the working fluid both heating the working fluid, as the working fluid passes through the working-fluid heating-vessel, and cooling the thermal-energy-storage material, said working-fluid heating-vessel further including thermal-energy-regeneration means for reheating the thermal-energy-storage material upon cooling of the thermal-energy-storage material; a heat engine for receiving from said working-fluid heating-vessel a flow of hot working fluid which passes through said heat engine and induces rotation of a heat engine output shaft; an alternator having a fixed stator and a moveable rotor which is coupled to an alternator shaft, said alternator also having a pair of alternator power output terminals for supplying an electric current to an external electrical load, said alternator shaft being coupled to the heat engine output shaft for rotation of said rotor by the heat engine output shaft, rotation of said rotor causing said alternator to generate an electrical potential across the pair of alternator power output terminals; a working-fluid radiator, structurally integrated into a chassis of the automotive vehicle for receiving a flow of the working fluid from said heat engine and discharging the flow of the working fluid back to said heat engine, radiation of thermal energy from said working-fluid radiator to atmosphere surrounding said working-fluid radiator cooling the flow of working fluid passing through the working-fluid radiator; an electric drive-motor adapted for being coupled to a wheel of the automotive vehicle; said electric drive-motor, responsive to an electric current supplied to said electric drive-motor, energizing rotation of the wheel; and an electronic control electrically coupled to the power output terminals of said alternator and to the electric drive-motor for receiving an electric current from the power output terminals and supplying a controlled electric current to said electric drive-motor.

2. The automotive vehicle of claim 1 wherein the thermal-energy-storage material is a ceramic material.

3. The automotive vehicle of claim 2 wherein said heat engine includes: a working-fluid turbine through which working fluid flows, said working-fluid turbine receiving a flow of hot working fluid from said working-fluid heating-vessel and exhausting the flow of working fluid, the flow of working fluid passing through said working-fluid turbine inducing rotation of the heat engine output shaft; and a working-fluid compressor that is coupled for rotation to the heat engine output shaft, said working-fluid compressor receiving a flow of the working fluid from said working-fluid radiator that is induced to enter said working-fluid compressor by rotation of said working-fluid compressor, the flow of working fluid discharged from said working-fluid compressor passing to said working-fluid turbine.

4. The automotive vehicle of claim 3 further comprising a working-fluid heat-regenerator having a regenerator hot-working-fluid inlet for receiving a first flow of hot working fluid from said working-fluid turbine, and having a regenerator hot-working-fluid outlet for discharging the first flow of working fluid to said working-fluid radiator, said working-fluid heat-regenerator also including a regenerator cool-working-fluid inlet for receiving a second flow of cool working fluid from said working-fluid compressor, and having a regenerator cool-working-fluid outlet for discharging the second flow of working fluid to said working-fluid heating-vessel, a flow of thermal energy within said working-fluid heat-regenerator from the first working fluid to the second working fluid cooling the first flow of working fluid through said working-fluid heat-regenerator and heating the second flow of working fluid through said working-fluid heat-regenerator.

5. The automotive vehicle of claim 1 wherein the thermal-energy-regeneration means is a working fluid exchange port into said working-fluid heating-vessel through which heated working fluid may be circulated through said working-fluid heating-vessel.

6. The automotive vehicle of claim 1 wherein the thermal-energy-regeneration means is an electric heater.

7. The automotive vehicle of claim 1 wherein the working fluid is an inert gas.

8. The automotive vehicle of claim 7 wherein the working fluid is a noble gas.

9. The automotive vehicle of claim 8 wherein the noble gas is argon.

10. The automotive vehicle of claim 1 further comprising a vehicle-control transducer coupled to the electronic control for transmitting a control electrical signal to the electronic control, the control electrical signal causing the electronic control to regulate the electric current supplied to said electric drive-motor.

11. The automotive vehicle of claim 1 wherein said electric drive-motor, responsive to energy received by the electric drive-motor from rotation of the wheel, generating an electric current, said electronic control receiving the electric current from said electric drive-motor and supplying an electric current to an electric heater included in said working-fluid heating-vessel.

12. The automotive vehicle of claim 11 further comprising a vehicle-control transducer coupled to the electronic control for transmitting a control electrical signal to the electronic control, the control electrical signal causing the electronic control to regulate the electric current supplied to or received from said electric drive-motor.

13. A thermal-energy-regeneration station adapted for reheating a thermal-energy-storage material contained within a working-fluid heating-vessel of an automotive vehicle, the working-fluid heating-vessel including a working fluid exchange port through which heated working fluid may be circulated through theworking-fluidheating-vessel, thethermal-energy-regeneration station comprising: a nozzle adapted for mating with and engaging the working fluid exchange port of the working-fluid heating-vessel; a pump coupled to said nozzle for circulating a flow of hot working fluid through the working-fluid heating-vessel of the automotive vehicle; a hollow furnace tube coupled between said pump and said nozzle, the flow of hot working fluid circulating through the working-fluid heating-vessel also passing through said furnace tube; and a means for heating said furnace tube.

14. The thermal-energy-regeneration station of claim 13_ wherein said nozzle is adapted for automatically mating with and engaging the working fluid exchange port of the working-fluid heating-vessel.

15. The thermal-energy-regeneration station of claim 13 wherein said furnace tube is formed from a ceramic material.

16. The thermal-energy-regeneration station of claim 13 wherein said means for heating said furnace tube heats said furnace tube by contacting said furnace tube with hot gas.

17. The thermal-energy-regeneration station of claim 16 further comprising: a heat exchanger having a heat-exchanger hot-gas inlet for receiving a flow of hot gas after the hot gas has contacted said furnace tube and having a heat-exchanger hot-gas exhaust for discharging the hot gas to atmosphere surrounding the thermal-energy-regeneration station after the hot gas has passed through said heat exchanger, said heat exchanger also including a heat-exchanger air-inlet for inducting a flow of air from atmosphere surrounding the thermal-energy-regeneration station and also including a heat-exchanger air-outlet for discharging the flow of air inducted into the heat exchanger after the flow of air has passed through said heat exchanger, a flow of thermal energy within said heat exchanger from the hot gas to the air inducted into said heat exchanger heating the air discharged from the heat exchanger; and a burner adapted for forming a mixture of a fuel with air discharged from said heat exchanger and for burning the mixture thus formed to produce the hot gas for contacting said furnace tube.

18. The thermal-energy-regeneration station of claim 17 wherein the fuel mixed with air is natural gas.

19. The thermal-energy-regeneration station of claim 13 further comprising an electronic system management centre for determining a price for thermal energy transferred from said thermal-energy-regenerationstationtothethermal-energy-storage material contained within a working-fluid heating-vessel of a automotive vehicle during reheating of the thermal-energy-storage material contained therein.