The present invention relates generally to efficient energy production and specifically to the very efficient production of electrical energy possible with a system and method that employs low energy nuclear reaction heat generation and thermionic devices for the conversion of heat to electrical energy.
As the fossil fuel supplies currently used for electric power generation continue to be depleted, much effort has been directed toward finding suitable replacements. Such suitable replacements should efficiently produce the energy needed to meet the demands of a power-hungry world population without the adverse environmental effects of coal or other commonly used fossil fuels. While nuclear power produces electricity without these specific adverse environmental effects, nuclear reactors currently in use present their own environmental challenges. For example, spent fuel is radioactive and must be properly disposed of, and reactor cores must be constantly cooled with water that is then discharged into adjacent bodies of water, raising temperatures beyond levels that can sustain most living organisms. Earthquakes and other natural disasters can damage reactors and back-up safety systems, causing the release of high levels of radioactivity into the ground, air, and water surrounding a nuclear reactor, making the area uninhabitable. Particularly in the aftermath of the Fukushima nuclear power plant disaster following Japan's tsunami of 2011, cleaner, more reliable sources of energy for electric power generation that are not accompanied by these adverse environmental and health effects are being sought.
One approach to the search for an inexhaustible, environmentally-friendly source of energy exploits a phenomenon of nuclear physics in which the reaction product of two atomic nuclei has a slightly smaller mass than the mass of the original particles, and the mass difference is ultimately converted to heat energy. Only a minute mass difference yields a very large amount of heat energy. Thermonuclear reactions currently used to produce electric power, as well as those used in the past to produce hydrogen bombs, employ this phenomenon, which, as noted above, can be problematic.
The concept of low energy nuclear reactions (LENR), which also exploit this phenomenon and were generally referred to previously as cold fusion, has been under investigation for some time, but these reactions did not live up to their initial promise. Low energy nuclear reactions and their potential commercial applications have recently received renewed focus, however. It has long been known that reactions between atomic nuclei produce a significantly greater output of energy than chemical reactions between molecules, although such nuclear reactions usually require a correspondingly greater amount of energy to initiate. A substantial benefit of low energy nuclear reactions is that these nuclear reactions can be instituted at ordinary temperatures, corresponding to less than 1 electron volt (eV), and can achieve output energies in the range of one million eV or more. This is also characteristic of nuclear reactions that require large amounts of energy to initiate and large reactor facilities in which to conduct the reactions. LENRs, in distinct contrast, need only a very small fraction of the input energy, can be conducted on a much smaller scale, and do not produce residual radioactivity or radioactive waste. Until recently, however, these high energy producing reactions were confined to laboratory scale investigations.
In 2011, Dr. Andrea Rossi demonstrated that low energy nuclear reactions can produce the energy required for a 1 megawatt (MW) thermal heat generating plant from nickel and hydrogen. The extremely high energy density achieved was determined to be a factor of 100,000 or more compared to combustion processes using fossil fuels. With only a low energy input, this system produces an environmentally clean energy output without radioactive byproducts or carbon emissions. This system is described and shown in U.S. Patent Application Publication No. US2011/0005506. The LENRs on which the Rossi system is based are weak interactions and neutron capture processes that happen in nanometer to micron scale regions on surfaces of condensed matter at room temperature. The reactions involved are high energy nuclear reactions that transmute elements, primarily nickel to copper, but do not generate radioactive waste.
U.S. Patent Application Publication No. US2007/0280398 to Dardik et al and U.S. Pat. No. 7,244,887 to Miley disclose, respectively, electrolytic cells for the creation of LENRs that generate heat and electrolytic devices that may be used, inter alia, to generate heat, convert heat to electricity, and/or cause transmutation reactions. Miley additionally suggests electrolytic cells in which selected metals react with hydrogen and/or deuterium, but in a different arrangement than used by Rossi. None of the foregoing art, however, suggests a high efficiency system or method for producing electricity that converts heat generated by low energy nuclear reactions to electricity using thermionic or thermotunneling converters or similar devices.
The generation of electric power can be achieved by a variety of devices and systems, including, for example, diesel generators, thermoelectric converters, thermal electric power plants, and fuel cells, which vary in their efficiency. Thermionic converters proposed for electric current generation in the past have not only been inefficient, but have required high operating temperatures. More recent thermionic devices have been improved. However, neither these nor other electrical power generating systems and devices have been suggested as efficient producers of electric power from heat produced by LENRs.
A need exists, therefore, for a high efficiency system and method for generating electricity that combines the efficiencies of a LENR system of producing heat and a thermionic converter designed to operate with high efficiency to produce electricity from the heat produced by the LENR system.
It is a primary object of the present invention, therefore, to provide a high efficiency system and method for generating electricity that combines the efficiencies of a LENR system of producing heat and a thermionic converter designed to operate with high efficiency to produce electricity from the heat produced by the LENR system.
It is another object of the present invention to provide a high efficiency electricity generation method and system capable of operating at efficiencies as high as 80% of Carnot.
It is an additional object of the present invention to provide a high efficiency electricity generation system and method that is substantially free from adverse environmental effects associated with available electricity generation systems from both fossil fuels and nuclear reactors.
It is a further object of the present invention to provide a method and system for efficiently producing electric power that is both compact and expandable to be used to provide electricity in a substantially unlimited range of applications.
It is yet a further object of the present invention to provide a highly efficient sustainable system and method for generating electrical energy from heat energy from relatively low temperature energy sources.
In accordance with the aforesaid objects, a system and method for generating electric power from relatively low temperature energy sources at efficiency levels not previously available is provided. The present system and method employ recent advances in low energy nuclear reaction technology and thermionic/thermotunneling device technology, first to generate heat, and then to convert a substantial portion of the heat to usable electrical power. Heat is generated by a LENR system premised on nuclear reactions, preferably those that occur in readily available materials at ambient temperatures and do not require high energy inputs or produce radioactive byproducts.
The heat generated by the LENR system is transferred through one or more thermionic converters or similar devices in heat transfer relationship with the LENR system to generate electric power.
Other objects and advantages will be apparent from the following description, drawings, and claims.
High efficiency systems and methods that produce electric power without adverse environmental impact have been the subject of much investigation, but available systems and methods have, thus far, fallen short of the concomitant goals of providing electric power with high efficiency and eliminating adverse environmental effects. It is becoming increasingly clear that reliance on existing or even new systems based on fossil fuels may not meet escalating global electric power demands without negatively impacting environmental quality. Although there may be available global fossil fuel reserves that have not been fully exploited, the combustion of fossil fuel using current technology to produce electricity can release undesirable levels of carbon, nitrogen, and sulfur oxides. Reliance on nuclear power plants for the electricity needs of a population dependent on electronic devices is also problematic, for environmental and other reasons. The present invention provides a unique alternative highly efficient power generation system and method capable of providing a substantially unlimited source of electric power without the potential adverse environmental and other consequences that characterize available power generation systems. The system and method of the present invention uses a low energy nuclear reaction (LENR) system to produce heat, which is converted to electric power by highly efficient thermionic/thermotunneling converter devices in heat exchange relationship with the LENR system. Both the preferred LENR system and the preferred thermionic/thermotunneling devices are capable of highly efficient operation at a wide range of levels.
Low energy nuclear reactions (LENR) are not based on nuclear fission or fusion, but, rather, are much weaker interactions that occur in condensed matter at ambient or room temperatures. Although weaker than fission or fusion reactions, LENRs are capable of producing highly energetic nuclear reactions and elemental transmutations. For virtually any nuclear reaction, the energy released is typically orders of magnitude greater than the energy released in a chemical reaction involving the same quantities of the same or similar reactants. LENRs, however, do not share the requirements or disadvantages of other nuclear reactions, which include very high input energy to start the process and the production of radioactive waste that must be disposed of. LENR systems are being widely studied, and a range of LENR systems has been proposed. Much of the experimental work relating to LENR is described in the papers available at www.lenr canr.org. There are many approaches to LENR systems that generate heat, including those described in U.S. Patent Application Publication No. US2007/0280398 to Dardik et al and U.S. Pat. No. 7,244,887 to Miley, referred to above in the Background of the Invention section. The LENR reactors described by Dardik et al and Miley include electrolytic cells, and the materials of the components of the electrolytic cells are selected to promote low energy nuclear reactions. Any of the known LENR systems that is capable of generating a supply of heat that can be converted to electrical energy by the thermionic converters in heat transfer relationship with the LENR system as described below could be used in the present system and method for high efficiency electric power generation. The LENR systems described herein are merely illustrative, and the present invention is not intended to be limited to use with any one specific LENR system.
The LENR system described by Rossi in U.S. Patent Publication No. 2011/0005506, the disclosure of which is incorporated herein by reference, and available under the name E-Cat in Australia and elsewhere is both compact and expandable and can be used effectively with the present system and method. The Rossi LENR system is premised on applying heat to a small amount of a micron-sized nickel powder in the presence of a catalyst in a pressurized hydrogen atmosphere to achieve a significant release of energy. Although the Rossi system is based on a reaction between nickel and hydrogen, a range of other nonradioactive metal elements may also be used to produce the desired LENR system, and these metals are also contemplated for use in the LENR system portion of the high efficiency electrical power generating system and method of the present invention.
An illustrative reactor core with a volume on the order of about 50 cubic centimeters (cm3) can use a few grams of nickel or other metal powder and a very small amount of hydrogen to safely produce about 10 kilowatts of heat. It has been demonstrated, for example, that the LENR reactor system of Rossi is self-sustaining and can continue to produce this amount of heat for six months or more. Additionally, if the temperature of the reactor becomes too high, unlike the situation in traditional nuclear reactors, the nickel or metal powder safely melts, destroying the reaction sites so that the nickel becomes unreactive, without the release of radioactive material. The addition of more nickel or metal is essentially all that is required to restart the process.
The energy produced by the reaction between nickel and hydrogen is presently used in the Rossi system to heat water or to produce saturated steam, primarily for applications requiring a reliable source of industrial heat in the 1 megaWatt (MW) range. An appropriate number of reaction vessel modules is connected together to provide this amount of heat. A smaller version of the Rossi LENR system, which is based on a single reaction vessel, is contemplated for residential use to provide hot water and heat in the 10 kiloWatt (kW) range. The connection of this LENR system to a typical diesel generator to produce electric power has been suggested. Diesel generators, however, present environmental and other problems. Not only are they very noisy, but they require fossil fuels with their accompanying noxious emissions for operation.
The high efficiency electricity generation system of the present invention is designed to use the heat produced by the LENR system described above or any other LENR system that effectively produces a source of heat without the drawbacks of traditional nuclear reactions. The heat produced by the LENR system is converted to electricity at a very high level of efficiency, up to as high as about 80% of Carnot efficiency, and preferably in the range of at least 50% of Carnot efficiency. Electrical power can be generated with the present system and method in an operating efficiency range of at least 10% of Carnot to 80% of Carnot. This very high operating efficiency is preferably achieved by one or more thermionic/thermotunneling converter devices as described below. Presently available thermoelectric converter devices used to produce electric energy claim to operate at higher than 10% of Carnot, but their long term operation is actually closer to about 5% of Carnot. The thermionic converters of the present invention represent a significant improvement over these available devices.
The thermionic/thermotunneling converter devices described herein can be more specifically described with reference to the following terms:
“Thermionic or thermotunneling converter” is hereby defined as either a device that uses a thermal gradient to create electrical power or a device that uses electrical power or energy to pump heat, thereby creating, maintaining, or degrading a thermal gradient. This may be accomplished using thermionics, thermotunneling, Avto effect, or other methods. In the present description of the invention, “thermotunneling” is used by way of an example only. The terms “Avto metal” and “Avto effect” are to be understood to describe a metal film having a modified shape that alters the electron energy levels inside an electrode modified accordingly, leading to a decrease in electron work function. The Avto effect enables the custom design of electron work function in a film or electrode to produce a desired work function range measured in electron volts (eV). Further, as used herein, the term “electrode” is intended to include either or both an anode or a cathode, as appropriate.
Thermionic and thermotunneling converter devices may include at least a pair of spaced electrodes maintained at a desired effective distance from each other by spacers without requiring the presence of active elements. Surfaces of such electrodes may or may not include Avto metals patterning. Devices of this type and a method for making such devices are described in commonly owned U.S. Patent Application Publication No. US2009/0223548 by Walitzki et al, the disclosure of which is incorporated herein by reference. The silicon-based devices shown and described herein provide useful and effective thermionic and/or thermotunneling converter devices. The owner of the present invention presently develops and provides thermionic and thermotunneling converter devices under the name POWER CHIPS™, as well as other related products. POWER CHIPS™ refers to devices that use a thermal gradient to create electric power. A preferred thermionic/thermotunneling (POWER CHIPS™) device for use in the system and method of the present invention is shown in
Referring to the drawings,
While the dimensions of the indents required to produce the Avto effect may vary, a depth in the range of approximately 5 to 20 times a roughness of the surface and a width in the range of approximately 5 to 15 times the depth are preferred. The dimensions of the indents affect the transfer of electrons through the preferred thermionic and/or thermotunneling device and may be defined on a nanoscale level in nanometers, and the specific dimensions selected may vary.
Each electrode 22 and 24 may have on surfaces facing the gap 27, the preferred Avto metal structure shown in
Although the thermionic converter 20 may be positioned directly between a heat source in contact with element 30 and a heat sink in contact with element 32, this is not intended to limit the scope of the present invention, but is provided to illustrate one possible arrangement of the heat transfer/electric power generation system of the present invention. Various methods for connecting thermionic converters in heat transfer relationship to a heat source produced by LENRs are possible and are contemplated to be within the scope of the present invention. A heat sink in thermal contact with the element 32 of the thermionic converter 20 may also be any one of a number of suitable heat sink structures for transferring heat energy to be transformed to electrical energy.
In some applications, in addition to the transfer of electric energy from the thermionic converter 20 to one or more external circuits, any waste heat at the heat sink in thermal contact with the element 32 or heat that is not converted to electrical energy may also be transferred, for example to a home heating or hot water system. In accordance with the present invention, one or more thermionic converters could be attached or otherwise secured and positioned in heat transfer relationship between components of a LENR system and components of an electrical power system.
Arrows 40 in
Element 30, which is in contact with the low temperature side of the thermionic converter device of the present invention, may be formed of a suitable heat transfer material, such as, for example without limitation, a heat transfer material that can be formed directly on the electrode 22. Element 32, which is in contact with the high temperature side of the thermoelectric converter device of the present invention, may be formed from any one of a variety of materials suitable for heat transfer and/or the transfer of electric energy in a high temperature area. Suitable materials for these purposes may be selected from those available for this purpose.
Heat entering the thermionic converter 20 from the fluid line 62 may be transferred along the path designated by arrows 40 and 42 (
While only one thermionic converter 20 is shown in
While the present invention has been described with respect to a limited number of embodiments, those skilled in the art will appreciate numerous modifications and variations therefrom. It is intended that the appended claims cover all such modifications and variations as fall within the true spirit and scope of this present invention.
The present invention will find its primary applicability in providing a highly efficient electricity generating system that functions effectively at low cost in a wide range of possible applications.
This application claims priority from U.S. Provisional Application No. 61/646,226, filed May 11, 2012, the disclosure of which is fully incorporated herein.