ES2608601A1 - Thermofotovoltaic engine of metal fuel (Machine-translation by Google Translate, not legally binding) - Google Patents

Abstract

Thermofotovoltaic engine of metallic fuel. High temperature magnesium and aluminum combustión engine using oxygen as an oxidizing substance, which converts the generation of medium and far infrared radiation from said combustión into electric generation from a steam microturbine, and near infrared, visible and ultraviolet also in electrical energy through the use of high performance multilayer photovoltaic cells housed in the combustión chamber. The non-useful thermal energy in the cells is recycled by the thermal circuit of a steam turbine. This electricity can be used to provide electric power to a hybrid vehicle with a combustión-electric motor or to feed electricity and heat to a home. The chamber is made up of two hollow ellipsoids with a common axis of revolution whose intersection is a circumference with a center located at a common focal point. Thanks to the housing of the photovoltaic cells inside the combustión chamber, an advantage is obtained of the direct radiation produced in the combustión with a notable increase in the performance of the cells. (Machine-translation by Google Translate, not legally binding)

Description

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DESCRIPTION

Thermo-photovoltaic motor of metallic fuel.

Object of the invention

The present invention relates to a high temperature magnesium and aluminum combustion engine using oxygen as an oxidizing substance, and which converts the generation of medium and far infrared radiation of said combustion into electrical generation from a steam microturbine, and infrared close, visible and ultraviolet also in electric energy through the use of high performance multilayer photovoltaic cells. The unused thermal energy in the cells is recycled by the thermal circuit of a steam microturbine. This electricity is used to provide electric energy to a hybrid combustion-electric motor vehicle or to supply electricity and heat to a home.

Background and current state of the art

There is a branch of photovoltaic engineering known as thermo-photovoltaic, consisting of the heating of a substance that emits radiation that is mostly in a narrow range of the electromagnetic spectrum. This radiation is captured by photovoltaic cells with gap energy appropriate to the wavelength of the light received. The cells work in the infrared receiving radiation from bodies that place their emission temperature up to a maximum of 1600-1700 ° C which means a photonic energy that does not exceed 0.8 eV, losing much of the radiation in the middle infrared and far away that are unusable wavelengths.

There are also photovoltaic cells capable of withstanding light concentrations of up to 1500 soles, that is 150 W / cm2 used in concentration photovoltaic solar energy. They are cooled by water or air to lower their working temperature to 100 ° C or less.

Regarding efficiency, solar panels for space purposes, which operate in conditions of ford with high presence of ultraviolet and visible light, and have been exposed to degradation by oxygen, have efficiencies between 42 and 56%. Although according to some sources it is already reached 60%.

On the other hand, hybrid solar panels are marketed which on the face exposed to the sun is a photovoltaic panel and on the shadow side it is a thermal panel whose working fluid, in this case water or air, cools the photovoltaic panel and catch the heat of this.

The use of pure molten metals as fuel to be oxidized has been known for many decades. It involves capturing the heat released in an exothermic redox reaction or taking advantage of hydrogen evolution. The following patents have been identified: US2011 / 0005472A1; US6627340B1, US6007699, US4412421, US4248048, EP2912375A1, CN102623735A and US5728464.

The patents US7,963,115 B1 and their predecessors US7,900,453B1 and US7,430,866 B1 have been found, where in such an internal combustion chamber, such metals are oxidized

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as Magnesium, Aluminum and Silicon at the same time that hydrogen (later used in a fuel cell) and steam is generated by the incorporation of water inside the reactor. On the other hand, water is circulated that vaporizes in the space between the wall of this internal chamber and the internal wall of an external chamber (both are concentric), due to the heat given off by the walls of this reactor or internal chamber. This steam is used to move a turbine. There is an exit duct of the internal chamber to evacuate gases and a lower tank to capture the solid substance formed. Mg2AI4Si5 is proposed as fuel. On the walls of the combustion chamber thermoelectric cells are placed and on the internal walls of the external chamber photovoltaic cells are placed to capture the latter infrared radiation released by the wall of the internal chamber and by the hot steam. The final result being the generation of electric current.

However, although the patents US7,963,115 B1, US7,900,453B1 and US7,430,866 B1 have photovoltaic cells there are clear and important differences between what these patents disclose and what is now proposed. In said patents the photovoltaic cells are arranged in the space between the internal chamber and the external chamber, particularly on the internal face of the external chamber which implies an electromagnetic spectrum of reception by the cells completely different from that of the present invention.

The Condensation Type Thermophotovoltaic System CN 204206105 U utility model captures the infrared radiation emitted not only by solar concentration, but also establishes the possibility that such heat is coming from the burning of a fuel and enters the photovoltaic generation device through the wall of a radiator or condenser.

Japanese patent JP2004364483 is also referred to the use of heat energy and hydrogen from the oxidation reaction of magnesium, thus employing! same an electroturbine and a fuel cell for the generation of electric energy.

The introduction of oxygen in a high temperature furnace by means of the so-called oxygen lance is carried out for the processing of steel in so-called oxygen steel furnaces, which reach high efficiencies. The injection pipe is water cooled. Thermal oxygen lances are also used to cut steel, concrete, rocks, etc. In this case the emission rod itself melts and oxidizes. Inside it is usually placed, powdered magnesium, aluminum and silicon, in order to raise the temperature. According to patent W 2015103715A1, temperatures between 3500 ° C and 5530 ° C are usually reached. Working between 0.5 and 10 Kg / cm2 they achieve spectacular depths of cut and penetration of several mm / s even in ceramic materials.

Magnesium is used for lighting purposes in pyrotechnics (giving light intensity and producing a bright light), flares and in the 19th century it was used as a flash for photographs. Also formerly used to build lamps. It is a pure metal that has excellent chemiluminescent properties. The chemiluminescence of magnesium is one of the highest among the known substances, which is why it is used to give light in fireworks. Magnesium and aluminum infrared flares are used in military air technology in so-called countermeasure systems.

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Currently, xenon flash lamps are used to test and calibrate the efficiency of photovoltaic panels. Xenon lamps replaced magnesium in photographic flash.

In the origins of automotive engineering in the 19th century. steam vehicles were built. In the sixties of the twentieth century some rocket prototypes were built that reached 200 km / h. Especially significant is the US3861150 (A) patent of the brilliant Seifi Ghasemi and patented by Lear Motors Corporation, which used a steam turbine engine that sought to achieve high powers and whose water vapor worked at more than 65 Kg / cm2 and 537.77 ° C.

On the other hand, the construction of the Viking 29 is a milestone for the thermo-photovoltaic car, which has a 6.5 Kw thermo-photovoltaic generator that operated together with a gas turbine. The following patents for thermo-photovoltaic generation CN104802652 (A) cars have been found. US9296288 (B2), JP2014171301 (A), CN103244271 (B), CN101420195 (A) and US9376214 (B2).

The combination of thermo-photovoltaic cells and steam turbine is presented in the patent JP2015159715 Metamaterial Expanded Thermophotovoltaic Converter. The device receives solar radiation as an energy imput.

At present, fuel cell technology is more expensive and less durable than a turbine engine. The steam turbine is a well-known technology, most of the world's electricity is generated by this means, while the fuel cells are still in the experimental phase. On the contrary, the turbine has the disadvantage of acoustic contamination. For residential use, this inconvenience can be resolved if the device is built underground or with due acoustic insulation. Photovoltaic cells constantly improve their efficiency and lower their sales prices more and more and have a higher lifespan than a fuel cell.

Description of the invention

In the present invention, the use of water for the oxidation of magnesium and / or aluminum is omitted, for this reason hydrogen is not generated and consequently no fuel cell or chamber is used for hydrogen combustion.

In a reactor where the vacuum has been previously carried out, the fuel is introduced in the form of a thin sheet. It is either aluminum, magnesium or an alloy with magnesium matrix and aluminum microparticles, heated above 600 ° C when it reaches the geometric center of the chamber. The use of powdered metal is dispensed with. Although this is more reactive than the sheets, it has the drawback of producing particle scattering. These leave radially farewells from the focal area and their transport to the solid waste chamber is a problem, in addition to the need to prevent said particles from damaging the reactor walls given their abrasive character.

This heating is carried out by means of AC induction coils that wrap around said aluminum-magnesium tape. This is introduced into the chamber at a speed such that it provides a mexican flow rate to the reactor proportional to the power demanded.

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At the same time, through one or several pipes, oxygen is poured, at a pressure lower than the atmospheric to avoid explosive atmospheres, at high speed inside the combustion chamber. The mouths of the oxygen lines to the reactor point directly to the combustion source where the metal to be oxidized is located at a high temperature, so that the initial kinetic energy of the oxygen particles at the entrance to the reactor, causes Do not substantially change your trajectory, without being able to spread through the camera that has a partial vacuum. These collide directly with the metal sheet by oxidizing it or with the magnesium vapor formed around it, and consequently forming solid residue, or by heating the metal oxide itself until it is incandescent. We have the experience of the existing technology of thermal or oxygen lances for cutting at high temperatures, where, as indicated, temperatures well above 3500 ° C can be reached.

The absence of other gases and water vapor in the chamber prevents the transmission of heat by conduction and by convection of fluids to the external walls. Almost all of the energy of the reaction is dismissed from the internal area of the chamber, where the fuel is introduced, towards the walls, by exclusive electromagnetic radiation.

The radiation is mostly near infrared below 1900 nm. According to estimates, it stands at 65% of the total radiation emitted. Although the percentage of visible radiation (15%) and ultraviolet (2%) is considerable. Since combustion is carried out at average temperatures of 4000 ° K, the rest of the radiation (18%) corresponds to wavelengths greater than 1900 nm. In comparison, solar radiation on the earth's surface receives more energetic wavelengths: 3% of ultraviolet radiation, 38% of visible radiation and 59% of infrared radiation.

The particles of magnesium, aluminum and their oxides enter incandescence emitting a strong and intense white light, composition of the entire radiation of the visible spectrum. For magnesium oxide the dissociation-recombination temperature in the vacuum is 3700 ° K and for aluminum oxide it is above 4000 ° K.

For the temperatures given for aluminum and magnesium the maximum value of radiated intensity is located near the border between the visible and infrared range. According to the Wien displacement law for black body radiation (See figure 2)

% 0.0028976 m • K

The wavelength expressed in nanometers for 4000 ° K is 724.40 which corresponds to a light energy of 1.71 eV, well above the traditional thermo-photovoltaic methods that work at a maximum of 0.8 eV and normally operate at 0 , 5 eV. In addition, this emission is concentrated at the combustion focal point. If the reaction temperature is to be raised above 4000 ° K, silicon and zirconium can be added in minor proportions. The addition of these particles increases as well! same the brightness of the emission.

Black body radiation is an approximation to the real spectrum. Figure 4 shows the spectrum of emission of magnesium and magnesium oxide at 3250 ° K. It can be seen that the maximum emission is reached in the 700-750 nm range (a

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exception of the peak at 670 nm not always present). Said test is performed for combustion rates of 2 grams / s of Mg.

The electromagnetic emission spectrum of magnesium oxide at 5000 ° K is also attached below, which also allows another reference to be made of the foreseeable radiation, Figure 3 (graph according to Department of Mechanical Science and Engineering, Tokyo Institute of Technology) It can be seen that now the Maximum emission is approximately 500520 nm and as established by the black body theory and the Wien displacement function, as the temperature rises, it moves towards shorter wavelengths.

In both graphs the spectral lines of magnesium oxide at 500 nm and pure magnesium at 518 nm can be observed.

Very bright white light and ultraviolet radiation are emitted In the emission spectrum of pure magnesium, there are extremely intense spectral lines for magnesium in the visible 517 and 518 nm, 383 nm UVA, 275, 280 and 285 nm UVB, and in the uve . The high efficiency of the photovoltaic cells is achieved thanks to the optimal working conditions: reception of very energetic light that corresponds to peaks of intensity in spectral lines of exact wavelength, presence of vacuum in the path that describes the light (so that this does not dissipate energies by heating gases except for the reactive oxygen itself) and intense refrigeration of the cells. It is in much more favorable working conditions than in solar cells exposed to the outside environment on the earth's surface.

Traditional photovoltaic cells, with 1.1 eV gap energies for Silicon and above all 1.4 eV for GaAs, acquire good yields for a radiation whose spectral curve reaches its maximum wavelength intensity associated with 1.7 eV In the present invention a sandwich of "4-juction solar cells" of energies of gap 0.65-0.7 eV (Ge) is adopted; 1 eV (GalnAs); 1.4 e V (GaAs) and 1.7-1.9 eV (GalnP). The introduction of one more level (1 eV layer) with respect to the traditional multilayer cells, allows to more accurately capture the near infrared radiation, an important aspect to take into account given that the emission spectrum during the combustion of magnesium and aluminum is it finds more displaced towards the infrared than the solar spectrum on the earth's surface.

In the rest of the reactor the pressure below the atmospheric pressure is maintained because the product resulting from the reaction is exclusively solid. It is magnesium oxide and aluminum oxide also known as magnesia and alumina. As with other reactors for metal oxidation, the resulting solid product falls by gravity to an underlying chamber where it is stored. In the absence of water vapor or air, the resulting dust cannot be suspended and falls into the aforementioned chamber guided by the magnetic flow lines of an electromagnet that surrounds the access opening to the deposit of said residue. It avoids like this! that high temperature oxides damage the walls of the chamber.

The geometry of the combustion chamber is formed by two ellipsoids of revolution, with axis of common revolution and intersecting in the section perpendicular to the axis and passing through one of its focal points. Therefore, both ellipsoids share a common focal point located in the intersection area. The walls of the camera are internally reflective (except for the surface of the photovoltaic cells) and this

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Layer in turn is internally covered with another layer made of transparent ceramic material resistant to high temperatures (also the cells to prevent oxidation). The focal area of emission of the electromagnetic radiation, the geometric center of the combustion reaction, is located in the aforementioned common focal point of the two ellipsoids, while the photovoltaic cells are in a cross section to the axis and close to the center of the ellipsoids The light is transferred from the combustion focal area to the absorption zone where the photovoltaic cells are located, either thanks to the reflection produced by the revolution geometry of the reflective surface walls, or thanks to the direct radiation of the point focal combustion to cells.

In an alternative geometry, the combustion chamber has a symmetry of revolution, the radial section being a truncated ellipse at its center (which is the place where the cells are placed are also transverse to the radius) and at one of its focal points (zone of electromagnetic emission), said ellipse being eccentric to the center of revolution. The plates are arranged as an octagonal base prism, with their receiving faces exposed towards the combustion center. Said revolution geometry is interrupted only where the fuel inlet, combustion and solid waste outlets are located.

It is also possible to have photovoltaic cells in the infrared range arranged in the condensation chamber of the turbine and in the solid waste storage tank.

In the present patent, two schematic devices are presented, one for an average irradiance of 100 W / cm2 and another for 30 W / cm2. Concentration photovoltaic cells can reach a maximum irradiance of 150 W / cm2, which in the case of the present invention corresponds to peak powers. Moving the cells away from the emission focal point allows the light to expand and decrease the concentration and therefore reach the expected irradiance limits.

Magnesium has an energy density of almost 6.86 Kwh / Kg (21% less than carbon) and aluminum of 9.3 Kwh / Kg. The set of photovoltaic cells and steam turbine reaches a final efficiency exceeding 50% and therefore an energy density of 3.5-4.0 Kwh / Kg of a magnesium-aluminum alloy (magnesium in the majority proportion) can be used, much higher than the value of current electric batteries that do not yet reach 1 Kwh / kg. The density of magnesium is 1.74 gr / cm3. With a contribution of mass flow in magnesium and / or aluminum from 2.0 to 4 gr / s to the reactor, depending on the project power of the car, there is a sufficiently guaranteed energy contribution. This flow can be distributed in several mini-reactors, just as an internal combustion engine works with several cylinder-pistons, or perform all combustion through a single reactor of greater size.

In the current state of the art multilayer photovoltaic cells exceed a yield of 40% (hereinafter referred to high efficiency or high performance of photovoltaic cells refers to cells with performance equal to or greater than 40%) , and steam microturbine systems have a thermal circuit performance of 20%. In the present invention the efficiency is equal to or greater than 50% depending on the intrinsic performance of the microturbine as a machine. For a global efficiency of 50% in the combined thermal thermal photovoltaic system, 460 wh / km in energy consumption are required to match the power of the current

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fuel cells for hybrid cars, in an average speed situation of 120 km / h. These numbers determine the mass flow to be introduced into the reactors. The fraction of gross energy usable by the turbine is the majority of the fraction not absorbed by the photovoltaic cells. Therefore the gross power entering the thermal circuit is much lower than the indicated numbers, since it is necessary to discount the power already captured by the photovoltaic cells.

On the other hand, US Patent 3861150 indicates that for a steam turbine engine of 120CV = 88.20 Kw, the diameter of the drum of the combustion chamber required is 66 cm, sufficient for the space available in a medium-sized car, even more if the indicated in the previous paragraph is taken into account.

Unlike patents, US7,963,115 B1, US7,900,453B1 and US7,430,866 B1, where photovoltaic cells are placed externally to the combustion chamber and on the walls of this only thermoelectric cells are placed (which work according to the phenomenon thermoelectric), in the present invention the photovoltaic cells (which work according to the photoelectric phenomenon) are placed by arranging their receiving faces on the inner wall of said camera to capture not only the infrared radiation, but also the visible radiation of the luminescence of the magnesium and the aluminum. The production of hydrogen and the use of a fuel cell is dispensed with, as photovoltaic panels alone have reached a level of development in their efficiency that is competitive with these systems. As indicated, this is possible due to the absence of residual gases and abrasive particles in the combustion chamber, thanks to the use of metal sheets instead of fine particles of metallic powder, as imput fuel in the reactor.

In US7,963,115 B1, US7,900,453B1 and US7,430,866 B1, the combustion chamber is made up of refractory insulating walls made of rhenium and / or tungsten. In these patents, the direct radiation of the oxidation of the metals does not reach the photovoltaic cells given the presence of the opaque materials mentioned.

These receive the emission spectrum typical of the heating of these walls and the surrounding water vapor and not the emission spectrum of the oxidation of the metals as occurs in the present invention.

Regarding the cost of multilayer photovoltaic cells, the system is sized so that maximum efficiency is achieved when the car engine works at medium power. Efficiency records have been reached both for concentrations of 300 soles or 30 W / cm2 (Fraunhofer-Institute of Germany) and for concentrations close to 1000 soles or 100 W / cm2 (US NREL). The high price of multi-junction cells due to their constitutive materials (these are scarce materials), can be compensated by the high useful life of the cells. In solar technology, a useful life of 100,000 hours is estimated. In addition the material can be recycled.

On the other hand, in the current state of the art there are patents to capture the heat of a water condensation chamber in a Rankine circuit, which increases the efficiency of the radiator, for this type of vehicle. In this engine this measure is adopted and so! The thermal radiation of solid waste is captured by infrared plates in the waste chamber.

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In the case of motor use in a home, the hot water resulting from the cooling of photovoltaic cells can be used, which increases efficiency well above 50%. In an average house, only 4.5 KW of peak electrical power are required (if non-electric means are available to produce heat from the heating of the house), which can be solved with a small reactor and without using a turbine , leaving the hot water coming from the refrigeration for domestic use.

The main advantage of the present invention is the use of the proposed fuel because of its spectral emission curve. which leads to an efficiency in the conversion of photovoltaic cells above traditional values in thermo-photovoltaic energy. Until now the oxidation of metals has been considered a disadvantage in thermo-photovoltaic devices, although the present patent aims to prove otherwise. In addition, the thermo-photovoltaic motor does not require mechanical maintenance. with the exception of the rollers for the sheet to be introduced and the pressure reducing valves in the oxygen feed. And on the other hand, it is an advantage the growth of the global efficiency with respect to a simple combustion system to vaporize water, since the photovoltaic cells provide an increase in the global efficiency without losses, because the heat they give off is captured almost in entirely by the cooling water, which is used in the thermal circuit of the turbine. This has a sufficiently small size for the implementation of the turbine in a car.

The incoming oxygen can be stored previously liquefied in one or several cylinders intended for this purpose. For an autonomy of 500 km of a vehicle with average weight characteristics, approximate amounts by weight of the reactants are 30-35 kg of magnesium-aluminum and 20-25 kg of liquid oxygen. The energy density is somewhat poorer when compared to gasoline but with the advantage of greater efficiency than a gasoline engine

The advantage of introducing into the combustion chamber pure oxygen compared to doing it with air, is that the nitrogen in the air takes part of the radiation energy in the form of heat when it is fired by the exhaust pipe, while using oxygen Pure does not require a gas evacuation tube, this implies non-existent contamination and improved efficiency because there are no gases that dissipate heat outside. Having a combustion chamber with partial vacuum, no compressor is required as in combustion chambers of gas turbines, which has a substantial impact on improving efficiency.

It is possible to dispense with the storage of liquid oxygen in the car and use environmental oxygen, but it is not yet possible to completely eliminate nitrogen from the air with the oxygen injection flow rates required by the engine. There are patents to secrete oxygen from the air based on magnetohydrodynamics and centrifugation, but they only give an oxygen enriched air. In addition, the presence of nitrogen produces the reaction of this with magnesium creating magnesium nitride, a much less energetic reaction than with pure oxygen. What causes efficiency to fall. In addition, it will be required to evacuate non-reactive nitrogen, which will require filters to retain entrained solid waste particles.

Finally, the great argument against this patent is that aluminum has a current price of € 1.4 / kg. This means € 0.15 / Kwh. Therefore, comparing with gasoline with

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current price of € 1.14 / L, that is € 0.144 / Kwh, is apparently a fuel 1.31 times more expensive.

For magnesium, the price is € 2.25 / kg, which is a price of € 0.35 / kWh, which is 3.07 times more expensive than the Kwh from gasoline.

The previous numbers are not definitive in the comparison as it must be taken into account that the gasoline engine is less efficient than the present engine. For a vehicle that runs 20,000 km / year, the monetary cost for the gasoline engine, assuming a consumption of 7.0 L / 100Km, would be approximately € 1,600.0 / year. For magnesium, assuming a consumption of 6.7 kg / 100 km, it will be approximately € 3000 / year. Now the ratio is 1.88 times the magnesium fuel more expensive than the expense of the gasoline engine.

For aluminum, taking into account that the energy density by weight of aluminum is equal to the energy density of gasoline by volume and that the engine of the present invention has an efficiency of 50% compared to 30% of gasoline , the comparison ends in victory for aluminum.

For magnesium, the € 2.25 / Kg used as the initial price for comparison, refers to the cost of production that includes the entire process from the mining of impure ore to its disposal in ingots. On the contrary, the dissociation and reduction of magnesium oxide for the recycling of the solid residue of the present motor can be done simply by increasing its temperature until it reaches the dissociation value in a single step or process.

This temperature increase. In general for metal oxides, it can be carried out through the use of renewable energies and especially through the use of solar energy, which substantially lowers the above amounts to competitive levels. There are patents in this regard such as JP2015101765A, JP2014231917A. JP2014084501A. Even more so if the European states begin to have surplus production in electric energy because of the contribution of renewable energies and as indicated there is a problem in the storage of said energy. Hydraulic potential energy is a good option for this storage but there are not always available waterfalls, as is the case of a country with its mostly dry territory such as Spain. The reduction of metal oxides is a viable alternative for energy storage as it is intended to demonstrate the aforementioned patents and the present invention.

Magnesium has the following advantageous properties as fuel:

1. - Great abundance. It is element number 8 in order of abundance on the surface of the earth's crust. It is about 2.1% of its total mass.

2. - Geographical distribution uniform. It is therefore accessible to most of the countries in the world because it is present in the oceans in a proportion of 1300 ppm.

3. - Ease of obtaining and recycling. Magnesium oxide has the great virtue of dissociating before gasification, which is a great advantage over other metal oxides. Therefore, ease of recycling.

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4. - Low combustion temperature. Facing a reactor is a good property in the process of initialization of combustion or oxidation.

5. - Ductile and manageable. For its introduction in the reactor as a sheet it is an advantage.

6. - Energy density. It is about 70% of the energy density of gasoline, therefore an acceptable magnitude. This aspect is especially significant in relation to the weight to be transported.

7. - Reactivity with oxygen. For thin sheets the oxygen reaches the total penetration or diffusion without leaving particles inside it without reacting.

8. - Chemiluminescence Together with aluminum and zirconium, it is one of the metals with the highest electromagnetic emission in the visible range when it oxidizes, and its reaction temperature is very high.

9. - Non-polluting. The residue after combustion is solid and therefore can remain stored in a tank arranged for this purpose. Therefore guarantees zero emissions.

10. - Good electrical conductivity. This allows heating to the combustion temperature using electrical methods.

In comparison, aluminum is higher than magnesium at points 1, 6 and 8, but lower by 2, 3, 5 and above all 7. Aluminum finely ground and scattered on a matrix of magnesium can thus! replace its lack of reactivity due to the formation of the problematic non-reactive Al2O3 film on its surface during combustion.

In short, it is therefore an authentic solar drive motor, because the fuel can be of solar origin and the engine is partially supported by the technology of photovoltaic panels, which are electric converters born from solar engineering and on the other hand the Technology of steam turbines are also used in solar power plants in this case thermal.

Explanation of the figures

Figure 1. Shows a representation of the photovoltaic engine plant.

Figure 2. Shows the representation of the section made in the plant by the A-A plane.

Figure 3. Shows a representation of the engine plant in an alternative execution

Figure 4. Shows a representation of the section made in the engine plant by plane B-B.

Figure 5, Shows the spectral curve of the black body according to temperature.

Figure 6. Spectrum of emission of magnesium oxide at 5000 ° K.

Figure 7. Spectrum of emission of magnesium oxide at 3250 ° K.

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Preferred Embodiment of the Invention

Between figures 1 to 4 the fuel inlet (1) can be seen in the reactor. These are sheets or tapes of 0.15-0.3 mm or magnesium, or aluminum or magnesium aluminum alloy.

The tape is wound on a reel or drum (12) rotating electrically operated, which unwinds to the combustion chamber by rollers acting as guides. The feed rate determines the mass flow rate introduced into the combustion chamber.

In the vicinity of the entrance to the combustion chamber, the insulating conduction through which said foil advances is surrounded by a sealed enclosure in which an induction coil (11) is located, internally cooled by water, which preheats the fuel during the start. On the other hand, the electroiman (5) causes the magnetic field lines to densify as they pass through the wrapping surface. When the sheet reaches the geometric center of the combustion chamber, the induced currents raise the temperature on the surface of the fuel to more than 600 ° C, thus reaching! the combustion conditions of magnesium and aluminum. Before reaching the geometric center of the chamber, the temperature is lower than the combustion value and therefore it is not possible. Thus, the entry of oxygen into the guiding duct of the sheet does not imply the danger of premature combustion in an inappropriate place.

However, the storage chamber of the metal reel is sealed, insulated and devoid of oxygen.

Once a reel (12) is exhausted, its reposition is carried out by means of an automatism that can be seen in Figure 1. Once the first reel is exhausted, the next one slides until it is placed in the exact position aligned with the axis of the reactor. The reels or reel support rollers, fully unwound, are moved through their support slides allowing passage to the next reel with their respective drums. There are reels on both the right and left sides. An alternative exhaustion occurs to maintain balance of weights in the set.

Once the combustion has begun in the central area of the chamber, the rate of advance of the sheet and the oxygen inlet flow rate are such that the focal point of combustion remains static in the center of the chamber, without combustion advancing upwards. through the fuel inlet duct.

For the transport of oxygen, from its storage tanks to the combustion chamber. It features the characteristic oxygen manipulation devices (not drawn) of a thermal lance for the cutting of high thermal resistance materials, that is: liquefied oxygen cylinders, pressure regulator equipped with pressure reducing valve and pressure gauges (one before the valve and another one in the direction of advance of the oxygen), at its exit flow prevention devices and flame blockers, high pressure flexible tube, the so-called hose holder equipped with non-return valve and flow regulating valve and Pressure. In the case of the present invention, the final part or hose is replaced by placing a non-oxidizable and hollow tube (2) replacing the steel tube filled with metal material of this technology. Said tube (2) has its walls cooled by water (refrigeration not drawn) to prevent them from becoming reactive to oxygen. Also at the exit of the bottle of

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oxygen there is a safety or pressure relief valve. This device is also similar to that used for oxyacetylene welding in regards to the supply of oxygen.

The interior of the combustion chamber is globally below atmospheric pressure by means of a partial vacuum in which outside the combustion area the only gas present is oxygen gas at very low pressure. A vacuum pump connected to the combustion chamber and another to the solid waste chamber come into operation if the oxygen pressure is raised above the set working value, this being well below the atmospheric pressure (not drawn) . The combustion chamber also has a pressure relief valve (not drawn), in order to avoid an accident if the pressure rises above the atmospheric pressure.

For the engine stop. or in case of detention of the descent of the metal sheet, the oxygen supply is automatically cut off by means of electronic safety devices.

In case of failure, stopping the descent of the lamina and permanence of oxygen supply until the opening of the pressure relief valve, the valve (18) also acts. It is a shut-off valve that activates if the temperature rises above inadmissible values when the combustion center rises erroneously through the supply line. In this case, when the ductility of the sheet is increased by the increase in temperature, said shut-off valve equipped with blades cuts the sheet or tape and closes the possible entry of some oxygen into the tank where the reel is located.

The internal combustion chamber has its reflective walls (9). with the exception of the surface of the high performance multilayer photovoltaic cells (8) which is refractive. The geometry of the combustion chamber, in a first configuration, for cells working at 100 W / cm2 of medium irradiance, is formed by two hollow revolution ellipsoids and sections truncated by their common focal points. In the focal geometric point common to both is the focal area of combustion and therefore radiation emission. In the cross sections to the axis of revolution near the center of each ellipsoid are the photovoltaic cells (8), these being flat and circular, multilayer and high performance. The ellipsoid revolution geometry allows the reflective surfaces to transport the light from the central focal area to the photovoltaic plates (8), for that non-direct radiation.

In a second configuration or arrangement, in order to increase the reception surface, for cells working at 30 W / cm2 of medium irradiance, the combustion chamber or internal chamber, has a geometry with revolution symmetry, the radial section being a truncated ellipse in its center (which is the place of disposition of the cells placed these also transversely to the radius) and in one of its focal points (electromagnetic emission zone), said ellipse being eccentric to the center of revolution. The plates are arranged as an octagonal base prism, in order to take advantage of the currently existing fabrication in the form of a flat surface. After the photovoltaic panels, the geometry that separates the internal camera from the external one is a semi-ellipsoid of revolution. This arrangement allows the height of the engine to be decreased by a few centimeters. The reflective surfaces (9) are constituted by a first inner layer of very fine transparent ceramic material resistant to very high temperatures, which aims to protect the metal from corrosion due to high

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temperatures in the internal chamber, such as crystallized magnesium oxide in the cubic system and melting at 2852 ° C. Quartz and other technical ceramics resistant to high temperatures are also applicable. Below or externally to this transparent layer is a surface of said reflective metal such as aluminum clad steel or chrome steel.

There is a tramex lattice or lattice as a mini-structure on the face not exposed to light and on the water side, in order to give support and structural resistance to the plate on which the photovoltaic cell rests. This is an important aspect to take into account, given that on the water side there is a pressure of several tens of atmospheres, while on the side of the incident radiation there is a partial vacuum. For simplicity of drawing this structure has not been indicated in the figures. The dorsal (10) of the photovoltaic cell as indicated supports on a plate and is made of a material of high thermal conductivity and mechanical resistance. Aluminum, copper and magnesium alloys fulfill this property, where aluminum is the majority element and minor copper and magnesium.

The incoming water for cooling the dorsal zone (10) comes from the condensation chamber of the Rankine thermal circuit of the steam turbine.

The reaction is strongly exothermic inside the reactor and almost all of the energy stored in the form of electromagnetic radiation is released as discussed. The radiations with useful wavelengths 82% are intended to be used in multilayer photovoltaic cells (8). The unused heat that is generated is captured by the cooling water (4), thanks to the back plate (10) of the high-performance photovoltaic cells (8) and the tramex grid that gives off the excess heat, and transported to the inside an outer chamber (17) by converting liquid water to steam (14). This feeds an electroturbine (15) (figure 2). The internal combustion chamber is surrounded by another external chamber (17) through which the water flows, which, when heated, enters a vapor state. In the scheme, the cooling water inlet ducts (4) have been drawn to the photovoltaic cells. This cooling water comes from the steam condensing chamber that passes through the turbine, thus closing the circuit.

The final residue is Magnesium Oxide and Aluminum Oxide that are stored in a tank (6). Taking advantage of the magnetic character of the magnesium oxide, the electroiman (5) in the form of a hollow cylinder or ring, creates a field whose flowways (13) open in funnel, confining and guiding the solid particles towards the nozzle of the storage tank .

In this situation an energetic delivery of the electroiman (5) is required during stable operation, lower than the initialization situation. The electroiman coil (5) is water cooled. Its external wall forms part of the walls of the combustion chamber, thus avoiding that it contributes to the heating of other metal parts other than the metal sheet itself to be heated.

In the inner walls of the upper area of the waste tank, infrared cells (not drawn) are also placed in order to capture the infrared radiations of the ash. The dust or ash from the solid waste deposit, once the storage tank (6) is full, is sucked through the ducts (16), prior to closing the gate valve (7) and filling the vacla part with air of the deposit.

There is an automated shovel (19) to redistribute the solid residue through the storage chamber and prevent it from clogging the inlet mouth.

The photovoltaic cells send the electric energy to a regulator, then to a battery and from this to an inverter of alternating current, which gives electricity to the house or to the electric motor of a hybrid car.

With regard to the thermal circuit of water, to improve the efficiency of the steam microturbine. Its axis is floating on magnetic fields, thus avoiding the friction of the shaft with solid supporting parts.

The thermal steam circuit has not been drawn.

Claims (18)

5 10 fifteen twenty 25 30 35 40 Four. Five fifty 1. A method of thermo-photovoltaic electrical production of metallic fuel characterized by capturing by means of high-performance photovoltaic panels electromagnetic radiation from the combustion of either Magnesium or Aluminum or both jointly alloyed, upon contact with Oxlgeno. Said method comprises the steps of: - Initiation. It comprises the following phases: - Realization of partial vacuum inside a reactor or combustion chamber where there is only oxygen. - Introduction of Magnesium or Aluminum or an alloy of both in said reactor, and heating of this metal until combustion temperature is reached. - Introduction of Oxygen and projection of this on the heated metal. Combustion reaction start. - Continuous introduction of Oxygen at the same time as said metal in the mentioned reactor and projection or launch of Oxygen on the metal. Combustion reaction between these reactive substances. - Captation of ultraviolet radiation, visible and near infrared. result of the combustion of said metal, by means of high-performance photovoltaic cells located inside the combustion chamber with its receiving faces on the inner wall of said chamber. - Evacuation of the solid residue resulting from the combustion of said reactor. - Storage of the residue resulting from combustion in a sealed tank or enclosure. 2. Method of thermo-photovoltaic electric production of metallic fuel according to revindication 1, characterized by cooling the photovoltaic cells and the combustion chamber by means of water, or other coolant, following this fluid a closed thermal circuit vaporization-condensation-vaporization type Rankine 3. Method of thermo-photovoltaic electric production of metallic fuel, according to revindication 1 characterized in that the incoming fuel is heated by electric induction currents that place the said metal to be heated up to combustion temperature. 4. Method of thermo-photovoltaic electric production of metallic fuel. according to any of the preceding claims characterized in that the solid residue is evacuated from the combustion chamber by gravity, guided by magnetic fields. 5. Metal fuel thermo-photovoltaic engine in which the method according to any of claims 1 to 4 is characterized in that it comprises: 5 10 fifteen twenty 25 30 35 40 Four. Five fifty - a sealed enclosure whose interior is housed: - at least one reel or drum (12) rotating metal fuel - a combustion chamber with reflective walls (9) and high-performance photovoltaic cells (8) housed inside - an induction coil (11) arranged in the vicinity of the combustion chamber inlet - an electroiman (5) at the exit of this waterproof enclosure or combustion chamber - Oxygen introduction ducts (2) to this sealed enclosure or combustion chamber - a waste storage tank (6) placed next to the electroiman (5). 6. Metal fuel thermo-photovoltaic engine. according to claim 5 characterized in that the metallic fuel is sheets or tapes constituted of Aluminum or Magnesium or both together alloyed. 7. Metal fuel thermo-photovoltaic engine, according to claim 5 characterized in that the photovoltaic cells are multilayer constituted by a sandwich of 4 cells. "4-juction solar cells", of gap energies 0.65-0.7eV (Ge); 1 eV (GalnAs); 1.4 eV (GaAs) and 1.7-1.9eV (GalnP) of high efficiency for the transformation of electromagnetic, ultraviolet, visible and near infrared radiation, emitted in the combustion chamber, in electric energy. 8. Metal fuel thermo-photovoltaic engine, according to claim 5 characterized in that the combustion chamber consists of two hollow ellipsoids with a common revolution axis whose intersection is a circumference with a center located at a common focal point, this point being the combustion center and therefore also the focal point of emission of electromagnetic radiation , and being photovoltaic cells located perpendicular to the axis of the ellipsoids, with their receiving faces exposed towards the combustion center, where said revolution geometry is interrupted only where the fuel inlet, combustion and solid waste outlets are located. . 9. Metal fuel thermo-photovoltaic engine, according to claim 5 characterized in that the combustion chamber consists of a hollow ellipsoid, presenting revolution symmetry, the cells being arranged transversely to the radius and adopting these octagonal base prism geometry, with their receiving faces exposed towards the combustion center, where the revolution geometry is interrupted only where the fuel inlet, combustion and solid waste outlets are located. 10. Metal fuel thermo-photovoltaic engine, according to claim 5 or 8 or 9, characterized in that the internal wall of its combustion chamber has a transparent and high temperature resistant coating of non-reactive material with oxygen, such as cubic structure Magnesia , Quartz or Thermal Ceramics and 5 10 fifteen twenty 25 30 35 40 Four. Five externally to said transparent material, the walls of the indicated ellipsoids are constituted of Chrome Steel, or Aluminum Coated Steel. corrosion resistant. 11. Metal fuel thermo-photovoltaic engine, according to any of the claims 5 to 10 characterized in that the photovoltaic cells are supported by an aluminum, copper and magnesium alloy sheet, of high resistance and high thermal transmissivity, located on the face not exposed to the electromagnetic radiation of the combustion and which in turn supports on a reticular framework that constitutes its support structure and that allows the passage of water through it. 12. Metal fuel thermo-photovoltaic engine, according to claim 5 characterized in that the photovoltaic cells are cooled by a closed thermal circuit in which the heat captured by the cooling fluid is used to move a steam turbine that produces electricity. 13. Metal fuel thermo-photovoltaic engine, according to claim 11 characterized in that the combustion chamber is surrounded by another external chamber (17) that carries vaporized water at high temperature and pressure as a result of receiving excess heat from the photovoltaic panels and the reflective surfaces of the ellipsoids. 14. Metal fuel thermo-photovoltaic engine, according to claim 12 characterized in that it has a thermal circuit turbine that supports its axis on magnetic fields. 15. Use of the metal-fuel thermo-photovoltaic engine, according to claim 13, characterized in that the hot water resulting from the combustion chamber cooling is used to provide heat and hot water for residential application. 16. Use of the metal fuel thermo-photovoltaic engine, according to any of claims 5 to 14, characterized in that the combustion engine is used to move a hybrid car, sending the energy of the photovoltaic panels to a regulator, subsequently to a battery, and finally an inverter to convert direct current into alternating power by finally feeding the electric motor of the vehicle. 17. Metal fuel thermo-photovoltaic engine, according to any of the claims 5 to 14 characterized in that photovoltaic cells in the infrared range are placed in the condensing chamber of the turbine and in the solid waste storage tank. 18. Metal fuel thermo-photovoltaic engine, according to any of the Claims 5 to 14 characterized in that the magnesium, aluminum or both metal fuel sheets together have Zirconium and Silicon particles.