ES2688588A1 - Device for oxygen supply and disposal of solid waste with thermo-photovoltaic metallic fuel engine (Machine-translation by Google Translate, not legally binding) - Google Patents

Abstract

The present invention relates to a set of improvements to the operation of the engine described in the patent ES2608601. Specifically, the introduction of oxygen into the combustion chamber is solved by ionic transport ceramic membrane technology. The heat released by the high concentration photovoltaic cells is used to heat air using a heat exchanger. A compressor driven, either by electrical energy or by a microturbine coupled on its axis, contributing the latter to the improvement of electrical efficiency, compresses the air already heated by the heat captured in the heat exchanger to achieve conditions suitable to the oxygen transport through the ceramic membrane. The evacuation of the solid residue of metal oxide consists of a vortex flow of pure oxygen, which stabilizes and confines the combustion flame of magnesium and/or aluminum and entrains the solid particles. The nanoparticles form clusters until they reach the micrometric size using the technology of aerosol reactors. The start of combustion is produced by the concentrated light provided by a CO2laser. (Machine-translation by Google Translate, not legally binding)

Description

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DESCRIPTION

Device for oxygen supply and solid waste disposal to thermo-photovoltaic motor of metallic fuel.

Object of the invention

The present invention relates to a set of improvements to the operation of the engine described in patent ES2608601 and with application number P201631217 by the same author. Specifically, the supply of oxygen to the combustion chamber is resolved by means of ceramic membrane ion transport technology. The heat released by the high concentration photovoltaic cells is used to heat air by means of a heat exchanger. A compressor driven, either by electric power or by a microturbine coupled on its same axis, contributing the latter to the improvement of electrical efficiency, compresses the air already heated by the heat captured in the heat exchanger until adequate conditions are reached. oxygen transport through the ceramic membrane. The evacuation of the solid residue of metallic oxide consists of a vortex flow of pure oxygen, which stabilizes and confines the combustion flame of magnesium and / or aluminum and drags the solid particles. The nanoparticles form agglomerations until reaching micrometric size using aerosol reactor technology. The beginning of combustion is produced by the concentrated light provided by a C02 laser.

Background and current state of the art.

In the aforementioned patent ES2608601 the use of liquefied oxygen is proposed as a combustion storage medium to provide gaseous oxygen to a thermo-photovoltaic motor of metallic fuel, essentially burning magnesium and / or aluminum. However, liquefied oxygen is extremely dangerous due to its easy volatility. The rapid growth of the pressure inside the container and the easy sealing of the valves of the cylinders intended for storage, by the freezing of water vapor in these, with the consequent risk of explosion, poses a potential danger that inadequate for regular use, especially when the engine is intended to be used for transport.

Since last decades, the types of systems for obtaining oxygen from the air enter, the technique of ceramic membranes of ionic transport is known. They currently have the advantage of obtaining as a final result an oxygen of extreme purity, greater than 99% of the resulting gas, low energy consumption and as a disadvantage low productions, so they are not used massively in the industry.

Specifically, US5035727A patent deals exactly with the unification of external combustion turbine and compressor technologies plus oxygen permeation through an electrolytic ceramic membrane. Prior to the exit of already depleted oxygen through the turbine, the air acquires pressure conditions and temperatures suitable for the permeation of oxygen inside the turbocharger's heating chamber.

On the other hand, the use of electromagnetic radiation to heat a solar receiver, which in turn heats the air that circulates through the internal ducts of a gas microturbine, is proposed in the patent WO2013 / 034783A1 of the Spanish inventor Jonas Villarubia Ruiz. Also the Japanese patent JPH0431669A demonstrates that a gas microturbine can be driven by electromagnetic radiation, in this solar case, without the use of hydrocarbon gases.

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A device that combines thermo-photovoltaic cells, ceramic membrane and gas turbine is resolved in US2011027673, however it incorporates the use of a fuel cell, which differs profoundly from the scheme proposed in the present patent.

Also in CN103997281B and CN203911839 (U), the joint operation of thermo-photovoltaic chamber and gas turbine is proposed. However, burner exhaust gases are incorporated into the gas turbine, which implies a radical difference with the non-polluting engine proposed in ES2608601 and which seeks to improve the present patent.

The joint action of metal burning and oxy-combustion is sometimes used in the so-called Chemical Looping Combustion process.

The use of aerosol reactors for the growth and agglomeration of nanostructured particles has been known since past decades. It is thus possible to move from monomers of molecular sizes to particles in the micron range. In particular they are currently used for the growth of metal oxide nanoparticles. Some oxides obtained are those of Zinc, Tin, Magnesium, etc. Burning by diffuse flame is used, although methane is used as combustible gas and metal particles are projected on the flame. Thermophoresis or thermal gradient transport is a procedure used in aerosol reactors for precipitation and growth of nanoparticles on substrates or refrigerated surfaces.

They have exceeded 200 W / cm2 of light concentration in photovoltaic cells receiving solar radiation using liquid metal cooling. It is proposed by IBM in US6665186 B1 for semiconductor refrigeration and according to said entity set forth in 33rd IEEE Photovoltaic Specialists Conference. It is thus possible to pass the cell from 1600 ° C to 85 ° C.

Description of the invention

It is intended to introduce four advances or improvements to the thermo-photovoltaic motor of metallic fuel.

- Introduction of oxygen to the reactor.

In the first place, the use of ceramic ionic transport membrane provides the main advantage of the need to use an oxygen storage tank to carry out the oxy-combustion of magnesium or aluminum. This is a substantial advantage given that a gas cylinder for the storage of gaseous oxygen made of steel is heavy and subjected to high pressure (200 Kg / cm2), which implies a certain transport risk, when the engine is used to move a vehicle. Even more pronounced is the previous statement when it comes to storing liquefied oxygen.

The use of ceramic membranes to supply oxygen to a gasoline combustion engine has been proposed, but such use has been rejected due to its economic infeasibility. Accepting an energy consumption of 0.5 Kwh / Kg of oxygen. A gasoline engine would need to consume 40 kg of fuel, approximately 140 kg of oxygen. What would be a useful energy expenditure of 70 Kwh. Accepting a gasoline engine efficiency of 30%, the gross energy needed to obtain oxygen would be approximately 230 Kwh. Attributing 13Kwh / Kg to the energy density of gasoline, 17.69 Kg would be needed to have the oxygen needed to perform combustion. That is, 44% of the initial weight of gasoline. Almost half of the fuel's energy would go to obtain pure oxygen for the reaction.

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5

10

fifteen

twenty

25

30

35

40

For magnesium and aluminum, the numbers are very advantageous in relation to gasoline. If each particle -H-C-H- of the hydrocarbon chain weighs 14 units of atomic mass, which will bond with 3 oxygen atoms to finally form C02 + H20, a need for oxygen in total weight of 48 atomic mass units is imposed. On the contrary, in the case of magnesium oxide, each Mg particle weighs CU24 a. and you only need all 16

CU of the oxygen atom for the reaction. Therefore, for every kilogram of magnesium only 0.67 kg of oxygen is needed. Every 40 kg of magnesium will need to complete its combustion 26.66 Kg of oxygen. Assuming an energy requirement of 0.5 Kwh / kg for oxygen to cross the membrane, this implies 13.33 Kwh in useful energy. Attributing an energy efficiency to a thermo-photovoltaic motor + minimum gas turbine set of 35-40%, the gross energy requirement required is 35 Kwh. Since the gross energy density of Magnesium is approximately 7 Kwh / kg, this implies a need of only 5 kg of magnesium to burn the initial 40 kg. That is, 12.5% of the initial weight compared to 44% that requires gasoline. The calculation is even more favorable if one takes into account that, in the present invention, the energy lost in moving the turbocharger and heating the air is not necessarily produced electrical energy, but thermal energy.

It happens that magnesium and aluminum have an energy density referred to the weight of oxygen oxidizer used during combustion, much higher than hydrocarbons and even with respect to other metals.

Metal

Oxide Energy (KJ / mol of O2)  Metal Oxide Energy (KJ / mol of O2)

Beryllium

 Beo 1182 Iron Fe3O4 508

Magnesium

MgO 1162 Tin They are 500

Aluminum

Al2O3 1045 Nickel NiO 439

Zirconium

 ZrO2 1028 Cobalt CoO 422

Silicon

 SiO2 836 Lead Pb3O4 309

Chrome

 Cr2O5 701 Copper CuO 254

Zinc

ZnO 636 Silver Ag2O 5

Molybdenum

MoO2 534 Tungsten WO3 510

In the previous table the energy densities are compared according to the weight of oxygen. Only magnesium and aluminum are overcome by beryllium. Having this disadvantage of an excessive energy density that makes its manipulation dangerous, it is poisonous and not very abundant.

Oxy-combustion also has the advantages of preventing the formation of nitrogen oxides, and since there is no nitrogen present in the oxidation reaction, the heat lost from the heated gas outlet of the burner or heating chamber is substantially less than burning in the presence of air at atmospheric pressure, which results in a gain in energy efficiency.

For power plants other methods of obtaining oxygen such as air liquefaction are also applicable. This alternative is also adopted in this patent. The reason is that ceramic membranes are suitable for small productions such as supplying oxygen to a vehicle, but other methods such as air liquefaction are more appropriate for large productions. Therefore, for an energy plant, which includes the thermo-photovoltaic engine plus external combustion turbine and associated Rankine cycle, or steam turbine cycle, this alternative is best applied.

Oxy-combustion is currently used in hydrocarbon burners such as methane gas and the working pressure needed to permeate an ionic ceramic transport membrane is between 10 and 15 atm and the temperature is in the range of 800-1150 ° C. Ceramic membranes resist temperatures above 1100 ° C.

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For the present invention the working pressure range of the compressor is between 4.5 and 15 atm. The temperature of the air reached in the chamber or heating conduit prior to the passage through the ceramic membrane and the expansion of the air in the turbine is between 1000 and 1150 ° C. This temperature can be reached through a heat exchanger whose ducts through which the air circulates serve as a heating chamber.

The air then passes through ducts on whose walls the ceramic membrane is located.

The flow of oxygen through a ceramic ionic transport membrane is given by the Wagner equation,

 p o 

Jo  K (T)  ln  2 2  p o 

2

Where K is a parameter that depends on the temperature in the feed air. P'O2 is the pressure on the side of the feed surface and P "O2 is the pressure of oxygen on the permeate surface of the membrane.

Working the thermo-photovoltaic motor at lower than atmospheric pressure, the pressures of the feed surface side are substantially reduced, which is an advantage over hydrocarbon burners working from the permeate side at 1 atm and the feed side at 15 atm. The oxygen flow depends on the ratio between pressures and not on the difference in pressures, therefore working in partial ford inside the thermo-photovoltaic reactor of metallic fuel implies an energy saving because lower working pressures are required at the entrance to the membrane, and represents a substantial advantage over current technology where the ceramic membrane is used in hydrocarbon burners.

The temperature of the air inside the heating chamber of the proposed external combustion microturbine is obtained from the heat released by the concentration photovoltaic cells.

The advantage of obtaining more than 200 W / cm2 of light concentration on the cells compared to 100 W / cm2, is elementary, the number of cells is reduced by half. For a 40,000-watt light-emitting oxy-combustion reaction engine received by cells, the surface area in cells is reduced to 200 cm2 compared to 400 cm2 that requires working at 100 W / cm2. At € 20 / cm2, the cost in thermo-photovoltaic motor cells is 4,000 euros and is within an order of acceptable magnitude and the competitive technology returns to the electric battery and to the hydrogen fuel cells applicable in the automotive industry.

As already indicated, maximum temperatures, prior to the cooling of the cells, of 1600ºC are reached when working with light concentration on the 200 W / cm2 cells. With an efficient cooling system, the heat captured by a high thermal transmissivity liquid cooling metal, which acts in a heat exchanger, is transferred to the air stream inside the microturbine heating chamber.

For lower concentrations, the cooling requirements decrease but the surface area of photovoltaic cells increases.

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A compressor acts coupled to the microturbine using the same axis and provides the necessary pressure to the circulating air on the side of the feed surface of the ceramic membrane. Optionally you can do without the use of turbine and use the compressor driven only by electric power, the engine is simplified but the whole reduces its energy efficiency.

The pressure and temperature conditions in the turbocharger are compatible with its own operation and with the operation of the ceramic membrane.

- Efficiency improvement.

In the ES2608601 patent the use of steam turbine or Rankine cycle in symbiosis with the thermo-photovoltaic motor is proposed. This device is suitable for the operation of a power plant where the Rankine cycle associated with the use of steam turbines reaches yields that exceed 30% and by regeneration reach 40% (in this case this performance would be calculated with respect to the heat emitted by the Photovoltaic cells). In addition to the performance of the thermo-photovoltaic motor, said patent predicts an overall efficiency that reaches 50%. It is what is known in solar engineering with the terms High Concentration Photovoltaic Thermal system (HCPVT).

For a power plant, in the present invention the joint device of thermo-photovoltaic motor of metallic fuel without intermediate opaque emitter, gas microturbine and associated Rankine circuit is established, to take advantage of the heated nitrogen at the exit of the microturbine. There are thus 3 elements producing electricity: thermo-photovoltaic motor

+ heated nitrogen turbine (external combustion turbine) + water steam turbine.

For an automobile, an external combustion microturbine is more suitable in combination with a thermo-photovoltaic motor because it is the most compact indicated microturbine and therefore occupies less space than a steam turbine. In competition vehicles, using gas turbines is also reaching yields that exceed 40%, using energy recycling during braking.

In the current patent, the air that obtains thermal energy from a liquid metal heat exchanger that cools the photovoltaic cells, raises its temperature between 1000 ° C and 1150 ° C, which allows the operation of the turbine and therefore the associated compressor.

External combustion gas turbine technology exists and is known under the English terms of EFGT-cycle (the Externally Fired Gas Turbine). The present patent proposes a thermo-photovoltaic engine that feeds heat to an external combustion turbine, thus combustion being carried out within the metal-fuel thermo-photovoltaic engine. Combustion is an ultrafast metal oxidation.

The air at the outlet of the gas turbine is captured by a second heat exchanger and this is transferred for preheating the air before it enters the turbine compressor.

In part of the conduits through which the heated air circulates, inside the turbine's air heating chamber, a ceramic ionic transport membrane is available, in order to capture and permeate the oxygen towards the conduit that introduces it in the combustion chamber of the thermo-photovoltaic engine.

The differences with respect to the scheme outlined in Figure B of US5035727 consist of:

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one.

To the thermo-photovoltaic burner does not enter external air in the present patent and if the oxygen that crosses the ceramic membrane. On the contrary, the exhaust air of the turbine is delivered to the combustion chamber or burner of the US patent.

2.

The exhaust air of the gas turbine is used in the present invention in:

a.- Preheat the inlet air to the gas turbine compressor by means of a heat exchanger.

b.- Heat the oxygen used as entrainment gas before recirculation to the

inside the combustion chamber. US5035727 does not use

Oxycombustion in the burner.

c.- Heat the water of the Rankine circuit. If made in US5035727.

3. In the present invention the output material of the burner resulting from combustion is solid (the output oxygen is recycled and reintroduced into the burner). In the US patent there is burner outlet gas, which will transfer heat to a Rankine cycle in addition to delivering heat in the exchanger that supplies energy to the Brayton cycle turbocharger.

- Solid waste evacuation. The main problem associated with the thermo-photovoltaic motor of metallic fuel is the evacuation of smoke and metal oxide dust from the heating or burner chamber. When the opaque emitter is not used as an intermediary between the combustion zone and the photovoltaic cells, this element that has traditionally existed in thermo-photovoltaic energy, on the one hand it has the advantage of a reaction at a temperature above 3000ºC, which translates into a Spectral emission curve that reaches its maximum at the border between visible and near infrared radiation, excellent electromagnetic emission to be captured by concentration photovoltaic cells and with a great resemblance to the shape of the solar radiation spectral curve. But on the other hand, there is the associated problem of preventing metal oxide smoke from adhering to the combustion chamber walls, which would render the reactor useless in a few seconds, if this occurs. It is essential to evacuate the solid residue, smoke and dust that is formed.

For a motor vehicle and after a displacement of more than 500 km, the production of 70 kg of powder and metal oxide smoke is exceeded.

Although the magnesia has a high volumetric density, 3.58 kg / L, the smoke of non-densified magnesia has a behavior similar to silica smoke, its density is so low that it almost floats at atmospheric pressure. For the implementation of the engine described in ES2608601 in a motor vehicle it is necessary to proceed to smoke densification, even if working below atmospheric pressure, otherwise 70 kg of weight would occupy volumes of hundreds of liters. The same is also true for the storage of metal oxide in an energy plant, although space availability is much greater here.

The measures taken to remove dust and smoke from the combustion chamber are discussed below and are listed as follows:

a.- Magnetic confinement. Indicated in ES2608601.

b.- Fall and segregation by gravity. Indicated in ES2608601.

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c.- Dynamic fluid dragging due to thermal and pressure differences.

d.- Non-stick surface on the walls of the combustion chamber and smoke densification ducts.

e.- Distance between photovoltaic panels and combustion center proportional to the power to be received.

f.- Particles by way of iron nuclei surrounded by aluminum, magnesium or alloy of both. Iron acts as a solid carrier substance that guides the trajectory of burning particles.

g.- Mechanical cleaning of internal motor surfaces.

To solve the problem of evacuation in ES2608601 it is proposed to make use of evacuation by gravity and magnetic confinement. Magnesium is poorly paramagnetic and for aluminum, although its paramagnetism is greater than that of magnesium, it is still insufficient for the proposed purpose. In addition their respective oxides have an even weaker paramagnetism. The magnetic confinement of a particle of magnesium oxide or solidified and moving aluminum is insignificant. However, when combustion is taking place and the particles involved in it are placed in a plasma state, they are affected by magnetic fields following a movement described by Lorentz's law. For cylindrical magnets or electromagnets surrounding the fuel inlet and waste outlet ducts, of common axis and facing faces, the magnetic field flow lines take the form of a magnetic bottle. In this situation, the particles in the combustion process will move along a propeller around the magnetic flux lines and tend to leave the reactor through the axis of the magnets. This fact is foreseeable with high oxygen pressures that produce small explosions that initially leave the ionized particles with radial paths, after which they describe the indicated helical movement.

To reinforce the magnetic behavior during combustion, the present patent adopts the measure of using micrometric iron particles as fuel, in a matrix of aluminum, magnesium or both together alloyed, presented in the form of a tape or sheet. Micrometric powders constituted each particle of aluminum or magnesium or alloy of both surrounding a core or internal zone of chromium or zinc doped iron increases the paramagnetic character of the movement of the burning metal, also measured in the present invention. This does not contradict the basis of the ES2608601 patent which is to use the emission spectra of aluminum, magnesium or alloy of both, since the iron particles, without being important their own combustion because they have a poor energy density, are used only as carriers and guides of the indicated energy metals. Iron particles that are also oxidized maintain the magnetic behavior since iron oxides are paramagnetic. In addition, the presence of zinc and / or chromium prevents the oxidation of iron preventing its combustion and therefore its excessive heating. Avoiding the oxidation of iron also reduces oxygen consumption, which is important for the implementation of the engine in a motor vehicle. In a power plant, chrome and zinc doping can optionally be dispensed with.

When there is a stable diffusion flame, which occurs at low oxygen pressures, that is, on the order of 20,000 Pascals or less, the flame of aluminum or magnesium or alloy of both, as a whole is poorly affected by magnetic fields , unless these are very intense, of the order of several Teslas. In particular, the confinement attainable with permanent magnets, less than 2 Teslas is weak and only visible at short distances and at the root of the flame.

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Therefore, in order to reinforce the confinement, the dynamic action is incorporated into the magnetic action in the present patent, therefore there is a magnetohydrodynamic flow, due both to the presence of moving fluid and magnetic fields.

Using a reactor with revolution symmetry, and incorporating the oxygen in such a way that its movement constitutes a vortex flow with axis in the axis of revolution of the reactor, the confinement of the flame is achieved and thus avoids that the nanometric smoke adheres to the inner walls of the chamber. This measure does not necessarily mean that partial vacuum pressure is lost, a condition established in ES2608601. Oxygen can be incorporated even at a pressure below atmospheric. The oxygen output as a carrier gas and at low pressure from the combustion chamber does not imply large energy losses, in any case lower than working at atmospheric pressure.

From the area of the chamber where the photovoltaic cells are located, mouths of oxygen injector conduits are placed, guaranteeing the dragging of smoke and dust from the periphery of the chamber towards the center and towards the outlet duct (s), without prejudice to placing other pipes that directly project oxygen on the metal to be burned as established in ES2608601.

The moving fluid draws the nanometric dust towards the outlet outlet (s) of the reactor located on the axis of revolution of the reactor with revolution symmetry.

Impurities present in magnesium or aluminum, or other minor metals, do not pose an additional problem. The technical data sheets of the manufacturers report that the main impurities are iron, lead, copper, manganese and silicon. Limiting the maximum size to diameters of less than 0.1 microns, non-magnesium and non-aluminum particles are oxidized before reaching the walls of the chamber and dragged by the flow of oxygen. In addition, the particles of iron oxide and manganese are affected by the magnetic field even when it is created by permanent magnets, that is, even for fields less than 2 Teslas.

Magnesium oxide, if it reaches the walls of the chamber, its adhesion is low and can optionally be cleaned by mechanical means. It does not react with the reactor walls. There are already patented non-stick dust surfaces on the market, even for use in outdoor photovoltaic panels, in particular fluorocarbon materials prevent the formation of bonds that adhere dust. As a disadvantage they have their low melting point.

Only the walls of the chamber will be damaged if they are reached by liquid metal, which, when solidified, would form strong bonds with the constituent material of the wall, and cannot be cleaned by mechanical methods. To avoid this possibility, work under oxygen pressure above a minimum value must be guaranteed. At a pressure of 20,000 Pa if the surface of magnesium is not sufficiently polished from surface oxide before entering the reaction chamber, the tendency is to cut off the self-sustaining reaction and to drop burning drops of liquid magnesium from the flame that damages the reactor, when magnesium tape is burned.

In the ES2608601 patent, a single solid waste evacuation duct is established, with the understanding that the evacuation of gases (neither the existence of nitrogen nor of water vapor) is going to be practically null, there is no gas evacuation duct. Although it is indicated that if the working pressure is exceeded, a purge pump acts to relieve the reactor pressure, this need is also recognized in the present patent.

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In the current patent proposal the evacuation of the solid residue, either in the form of smoke or dust, there is the double alternative of being made downwards towards a deposit located below the combustion chamber, or by means of a double conduit, one rushing top and bottom burner. But in order to favor the flow of gas, a suction pump is placed inside the waste tank which aims to increase the pressure difference between the burner and the tank. The oxygen moves from the reactor to the tank with a strong temperature gradient. Under conditions of partial watt in the combustion chamber, the phenomenon of thermal drag occurs, in English called thermal creep, the speed and drag force of the current or flow are sufficient to evacuate the smoke. Furthermore, the weight of the smoke, greater than the weight of the gaseous oxygen, does not act as an opposite force or in countercurrent to the flow of oxygen, which facilitates the evacuation of both for the particular case of a single evacuation mouth at the bottom.

The dimensions of the burner or combustion chamber are determined by the oxygen pressure inside the reactor and by the massive fuel and combustion flow rates introduced.

The waste deposit practically receives no radiation, while the combustion chamber is permanently illuminated, which implies the strong temperature gradient. When a depression is created in the area of the waste deposit, the flame becomes inverted or downwards, in the case of a single evacuation conduit located inferiorly and inferior deposit.

When magnesium tape is burned by pressures not exceeding 20,000 Pascals, the stoichiometric proportions of the reaction exceeding the presence of oxygen, the lower the thickness of magnesium tape, the greater the proportion of cohesive solid residue as a "shell" of resulting magnesium oxide. This is the product of the passage of magnesium in a liquid state to solid magnesium oxide after reacting with oxygen. It is a proportion that ranges from 25% to 35% of the total weight of magnesium oxide produced. The remaining 65-75% is produced in the form of nanometric smoke. This nanometric smoke cannot be efficiently captured by conventional procedures, filters, cyclones, etc.

To solve this problem it is necessary to densify it previously, increasing the size of the particles, moving from the order of nanometers to the order of microns, thus evolving from smoke to dust. There are reactors known since past decades in order to densify nanometric smoke, used in electronics, pharmacy, etc. These are aerosol reactors, these are in particular used for the oxidation of metals and subsequent growth of nanometric structures. It is technology for the growth of thin films.

When the smoke travels a path through a tube of reduced diameter section, the smoke particles adapt to the diameter through which they circulate increasing their density or amount per unit volume. The longer the path and the smaller the section the more the probability of impact between the particles increases. Aluminum and magnesium oxides have an ionic bond, which tends to grow aggregates or agglomerations of particles, forming bonds by Van der Waals forces between the interacting or impacting particles. That is, the almost gaseous behavior of monomers and nanometric particles is changed to the behavior of the solid state of micrometric particles.

Another densification device of the initially nanometric particles consists in accelerating the flow of the smoke-carrying gas and also dragging it, by passing it through one or several nozzles or narrowings. After passing through the nozzle, the velocity grows and the particles are projected or finally thrown towards a chilled cold surface called substrate, where they precipitate and grow, while the drag gas dodges the surface. It is the known technique growth by thermophoresis.

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In the present invention, use is made of these smoke densification and evacuation devices, of a suction pump located in the solid waste tank to increase the pressure difference and of dust collection means, either by means of a filter or by cyclone or both simultaneously. The carrier oxygen, once purified of solid waste, is recirculated to the combustion chamber by an additional pump.

The aggregation and compaction method consists of the following steps:

one.

 Transport or drag of solid particles by a gaseous fluid stream under pressure.

2.

 Projection of the particles at high speed against a solid.

3.

 Finally at the same time they occur:

3.1 Evacuation and filtering and / or cycloning of entrainment gas.

3.2 Compaction of the solid particles deposited on the solid of step 2.

On the other hand, the cohesive solid residue resulting from the condensation of the liquid area of the flame, here called "husk" or magnesium oxide tape is embraced or surrounded by the inverted flame, in the case of a single lower evacuation duct . The place where the nanometric particles that constitute the smoke are formed, which in the case of inverted flame is located in the lower zone of the diffuse flame, embraces or envelops the solid residue "husk" that is producing the burning of the magnesium tape . The advantage of burning tape is that this residue, which is itself a magnesium oxide tape, constitutes a substrate for precipitation and agglomeration of the smoke itself. Therefore, smoke production is drastically diminished by this cause. However, the suction down to create the inverted flame pulls the magnesium oxide tape, and since there is a liquid phase on the combustion front, the tendency is to detach the area of already burned tape and even to the fall of liquid drops that stop the combustion progress. The method of adding smoke to the metal oxide tape works well with high oxygen pressures and small tape thicknesses.

In the case of an engine intended for transport, given the low availability of space in the vehicle, the micrometric dust once captured is densified by direct mechanical compaction by simply applying a pressing in the settling tank. Although hydraulic arms have been drawn to drive the press, the pressing movement can be done by other alternative devices: plain or vibratory rollers, connecting rod-driven pistons, etc.

Finally, the difficulties indicated regarding the evacuation of nanometric smoke are greatly diminished due to incandescent combustion and almost no smoke emission. It is possible if aluminum is burned in the form of macroparticles smaller than 10 microns in size and larger than 0.01 microns. Dropping aluminum dust from a vertical mouth that connects to the top of the burner, allowing the cyclonic current in the form of a vortex or oxygen vortex to drag the particles once burned into the lower nozzle dramatically decreases the amounts of smoke. Incandescent sparks speed up when they burn. With a microperforated sheet of thickness between 0.1 and 5 microns of aluminum or aluminum and magnesium alloy, the sparks of decimetric paths towards the reactor walls are prevented.

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A lithium aluminum alloy significantly increases the energy density of the fuel and can compensate for the decrease in energy density by the presence of iron particles.

- Combustion initiator heating medium. ES2608601 is proposed to use induced currents by means of electric induction coils. As an alternative, the use of a small C02 laser allows very localized heating at the end of a magnesium tape located exactly in the center of the combustion chamber. From there the reaction is self-sustained. In this way it is avoided that they can be heated by using the initiation means, unwanted areas outside the combustion chamber, regardless of the high thermal transmissivity of magnesium can heat the entire metal strip outside the combustion chamber. combustion. For example, the use of induced currents can heat metal parts such as reflective surfaces, metal conduits, etc.

In addition, the laser has the advantage over using other initiation means such as direct discharge by means of electrodes, placing this as far away as desired from the combustion starting area. This is not the case with induction heating, where the distance between the coil and the magnesium metal adversely influences the heating capacity.

Preferred Embodiment of the Invention

Figure 1 shows the planned operating scheme for mass and energy transfers. Cold air from outside (0) passes through the heat exchanger (31) that raises its temperature to 4009C. It is then sent through a conduit (1) to the compressor (2) that raises its pressure between 4.5 and 15 atm (3) depending on the final pressure of the permeate side that is intended to be achieved. It passes through the heat exchanger (4) where it captures the heat from the thermo-photovoltaic motor

(14)

 that the cooling circuit of the photovoltaic cells (15) - (16) - (17) is yielding in said exchanger (4). The air then raises its temperature to reach 1000 to 1150 ° C. The compressed and heated air (5) when the turbine path (9) circulates for its expansion has acquired conditions appropriate to the permeation of oxygen through the ceramic ionic transport membrane (6) found in the walls of the conduction by Where it flows Once a high percentage of oxygen has been transferred, the oxygen-depleted, heated and compressed air (7) reaches the turbine (9), expands by moving its blades, while moving the common shaft (8) with the compressor ( 2).

Then the semi-cold air at values above 1 atm and 500ºC (10), pressures and temperatures typical of the work of the heat exchanger of a combined cycle, passes through the heat exchanger (31), called in the technical literature, boiler of recovery, yielding heat. Finally the oxygen depleted air, cooled and at atmospheric pressure

(eleven)

 He is expelled abroad.

Meanwhile, the electric generator (12) of the heated air turbine, coupled to the turbine shaft, produces electrical power.

The heated oxygen (13) crosses the membrane, at a pressure preferably lower than the atmospheric pressure and enters the combustion chamber of the thermo-photovoltaic motor. Optionally, the device can be prepared to work at atmospheric pressure on the permeate side, increasing the pressure on the side of the feed at 15 atm, but with the disadvantage of having an explosive atmosphere in the combustion chamber of the thermo-photovoltaic reactor ( 14). The thermo-photovoltaic cells receive combustion light from the metals to a maximum concentration of 200 W / cm2 and to prevent burning of a cooling circuit, preferably with liquid metal fluid (15) cools the cells and discharges or gives heat into the exchanger (4). The cooling fluid, once cooled (16) passes through an impulse electric pump (17) that sends it back to the high thermal transmissivity plates where the photovoltaic concentration cells support. The cooling fluid must be kept liquid in a wide range of temperatures.

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Solid particles are generated during combustion, which is necessary to evacuate from the reaction chamber of the metal fuel thermo-photovoltaic engine, the metal being preferably

either magnesium, or aluminum or alloy of both. For this, the oxygen itself that has not reacted acts as carrier fluid or entrainment gas, transporting the metal oxide particles (18) out of the reactor. In order to capture the nanometric smoke it is necessary to allow its nucleation to agglomeration. For this, in (19), as will be described in detail below, elements designated as (48), (49), (51) and (52), smoke and dust concentration means are available. Oxygen and micrometric dust (20) are transported to another large chamber (21), where oxygen expands by a strong pressure drop and the powder falls by gravity to the bottom, where it is compacted by mechanical means (53). The oxygen in the upper part of the chamber (21), clean and free of dust, is driven (22) by a pump (57), by passing it through the heat exchanger (31), where it is heated and subsequently linked to the Oxygen supply lines to the combustion chamber of the thermo-photovoltaic reactor, from (32) to (13).

A steam turbine circuit completes the plant. The heated steam (23) in the heat exchanger (31) expands in the steam turbine (24), the semi-cooled steam (26) condenses in the condensing chamber (27) and the liquid water (28) is made go through a pump (29) and driven (30) back to the heat exchanger (31). The generator (25) produces electrical power. No regeneration circuits of the steam cycle have been drawn, these are already known in the current state of the art, nor for simplicity of drawing, heat capture means in the oxygen expansion tank (21). Externally, the installation of photovoltaic panels is applicable.

For means of transport, land vehicles, given the limited space, the steam circuit is dispensed with because it requires a condensing chamber that occupies a large volume and the operating scheme is organized as shown in Figure 2.

Regarding the collection of nanometric fumes and evacuation of the solid residue from the reactor, in figures 3, 4 and 5, schematic drawings are presented on how to incorporate oxygen into the reactor in order to drag said residue. As indicated above, it is about confining the combustion area through a vortex flow. It is possible to do so provided that the combustion chamber has a geometric shape approximated to a symmetry of revolution. The shape of the chamber determines the shape of the flame. In the upper part of figure 3, an elevation is shown and in the lower part a plant. The mouths of the tubes that supply oxygen to the thermo-photovoltaic reactor are positioned symmetrically with respect to the axis of revolution or with angular periodicity. These mouths or connections (37) are located in the vicinity of the location of the photovoltaic cells.

A ellipsoid of revolution (36) is placed as a preferred embodiment, on which two groups of four ducts each arranged, a group of four per each parallel piano, with angular periodicity of 90 hexagesimal degrees are landed on two parallel pianos. . These ducts (37), also drawn in plan in figure 4, represent tubes through which the oxygen penetrates into the chamber. The photovoltaic cells are arranged in the form of an octagonal prism (38). The propeller describing the fluid path (39) has been represented in plan. The inverted flame will evacuate its waste (40) through the nozzle (41). To increase the pressure from the upper side downwards, other pipes (42) directed towards the center of the chamber are placed by rushing the chamber from the upper face.

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To confine the incandescent bulb can also be done through other geometric shapes of reaction chamber: sphere, cylinder, intersecting revolution paraboloids, intersecting cones, etc., if the conduits rush the chamber with angular periodicity with respect to the center of rotation or revolution, the Revolution geometry of the incandescent bulb is then guaranteed.

In figure (5) a scheme has been represented that symbolizes the presence of a magnetic bottle-shaped field, corresponding to the presence of cylindrical magnets (43), at the metal fuel inlet mouth (63) and at the mouth of solid waste (41). The movement of the ionized particles during combustion follows a helix path (45) around the magnetic field flow lines (44). The fluid dynamic movement is reinforced by magnetic confinement, having both helix-shaped trajectories. The confinement of the combustion zone is carried out by joint action of the aerodynamic vortex flow (39) and by the action of the magnetic fields that create a magnetic bottle. The magnets or electromagnets (43) are facing and symmetrical with respect to the combustion center and located on the axis of revolution of the combustion chamber.

In figure 6 the device for agglomeration and densification of solid waste, miniaturized to be implemented in a vehicle is schematized. Although the cameras (21) and (64) have been drawn adjacent, they can be arranged separately, one in the front of the car and the other in the rear. The conduction (51) runs from one camera to the other.

All the walls of the chambers, both combustion and collection are covered internally by non-stick material, also the conduit (51) and the pump linings (49). The surface of the chamber (14) must also be transparent and stainless to protect the underlying mirrors, as already indicated in ES2608601.

When the carrier gas exits at high speed through the nozzle (46), the solid residue impacts the container (48) acting as a substrate. The thickest particles are incorporated into it and nanometric particles precipitate remaining attached. While the pump (49) performs suction keeping the enclosure (64) at a pressure lower than that existing in the combustion chamber (14). When this occurs the valve (47) is open.

That nanometric smoke still dragged by the oxygen current, passes through the pump

(49) and penetrates the flexible conduction of non-stick walls (51) or pump drive line. The nanometric powder densifies along the length of the conduit (51). The longer the conduit (51) and the smaller diameter, the greater the growth of the size of the transported particle, that is, the agglomeration grows, but on the contrary the greater the load losses or energy losses of the fluid and, consequently, loss of global performance by electric consumption in the pumps. There is a sharp decrease in section at the outlet (52), which further densifies the smoke and projects it outside at high speed.

The smoke, already transformed into dust, when it comes out through the mouth (52) acquires a size greater than 1 micron, is thrown against the adjacent horizontal substrate of the drawers (55) of the vacuum chamber (21), precipitating on it. The end (52) of the tube (51) is guided by a mini-bridge crane that responds to x-y movements on a horizontal piano, detail visible in figure 8.

The micrometric powder, not yet sufficiently densified, enters the chamber (21) where there is a vacuum, which accentuates the effect of gravity fall. The tendency to flotation is very low in vacuum conditions, so dust has a predisposition to descend. The pump (57) maintains an oxygen flow rate of the chamber (50) equal to that introduced by the pump (49), thus maintaining the vacuum conditions in the chamber. The bottom of the container is compartmentalized in separate enclosures (55) divided by partitions (54).

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Figure 8 schematizes the pouring and pressing of the detritus. A vertical ascent and descent press (53) consisting of a plate (66) suspended at the end of a hydraulic telescopic arm that slides on the gantry (67) of a mini-bridge crane, which moves on the ground in horizontal directions "x" - "y", presses the powder to compact it and decrease its volume. The sliders (68) of the crane bridge have coerced the vertical movement "z" but not the horizontal "x". Identically the sliders of the supports of the beams (67) of the bridge cranes are allowed the horizontal displacement "and" and coerced the vertical displacement "z". The horizontal piano supporting the mini-bridge crane (69) corresponding to the pressing is at a lower height or level than the one that supports the mouth (52) corresponding to the pouring, designated (70). A similar pressing device but of much smaller dimensions exists in the enclosure (64) to compact the powder in the drawer (48), not drawn for simplicity of drawing. A folding lining or canvas shirt protects the hydraulic cylinders of the telescopic arms, from abrasion of magnesia or alumina, not drawn.

The movements of the crane bridges are guided by computer.

The pump (57) sucks the oxygen from the chamber (21) already almost free of particles. The few that are still present in the evacuation gas remain attached to the filter (56). Finally, the particle-free oxygen (22) is sent to the heat exchanger (31).

In figure (7) the mode of emptying the debris deposits is schematized.

 The set of tanks (55) constitutes a single block (58) with freedom of movement of ascent and descent, after opening the sealed seals designated as (59).

 Similarly, the tank (48) allows horizontal sliding movement

(60) by wheels or sliders, not drawn, when the watertight gate is opened (61).

 The filter (56) can be replaced by opening the gate (62).

When the substitution operations are carried out the valves (65) and (47) remain closed so as not to lose the vacuum in the rest of the reactor. An undrawn pump places the chambers (50) and (64), once empty tanks have been restored, again under conditions of negative pressure and lack of air.

Figure 9 shows the reactor when it has a double evacuation duct, one in the upper part of the chamber and the other in the lower part, with two pneumatic pumps installed symmetrically. In this case, the fuel supply (not drawn) is lateral.

Regarding the use of iron particles coated with aluminum or aluminum-magnesium alloy, they enter the reactor from a conduit (63) located in the reactor in a higher position. They fall by gravity and magnetic attraction to the duct (41). It is then appropriate to dispense with the magnets (43) and place a single magnet in the lower part of the tank (48) in order to address the particles.

Finally, regarding the combustion initiation laser, the infrared, coherent and monochromatic light of the C02 laser is transported to the combustion chamber by means of reflective mirrors, and enters said chamber by means of a gate that closes when the combustion starts. combustion. Not drawn in the schemes.

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Claims (19)

image 1 image2 image3 1. Device for supplying oxygen to a thermo-photovoltaic motor of metallic fuel, being combustible metals or aluminum, or magnesium or alloy of both, characterized in that the oxygen to be introduced into the combustion chamber of the metal is obtained by permeating a ceramic transport membrane ionic from:  A compressor that raises the air pressure to values between 4.5 and 15 atm.  A heating chamber or conduit that raises the air temperature to reach between 1000 and 1150ºC. With both elements, compressor and heating chamber located before the aforementioned ceramic membrane, in the air circulation path.

2.

 According to claim 1, a device for supplying oxygen to a thermo-photovoltaic motor of metallic fuel, the fuels being metals or aluminum or magnesium or alloy of both, characterized in that the cooling heat of the photovoltaic concentration cells is used to heat the air that supplies of oxygen the ceramic ion transport membrane mentioned in claim 1, by means of a heat exchanger and a cooling circuit of the solar cells, which introduces and evacuates fluid of high thermal transmissivity both in said heat exchanger and in the photovoltaic cells following a closed circuit The indicated heat exchanger provides the heating chamber or conduit cited in claim 1.

3.

 According to claim 2, a device for supplying oxygen to a thermo-photovoltaic motor of metallic fuel, the fuels being metals or aluminum or magnesium or alloy of both, characterized in that the residual air after giving oxygen to the ionic transport ceramic membrane indicated above and therefore depleted of oxygen, it expands by moving a turbine that in turn moves the compressor indicated in claim 1 for having a common shaft, this being necessary to grant adequate pressure conditions to the passage of oxygen through the ceramic ionic transport membrane. The turbine and compressor assembly move an electricity generator located on its same axis. The turbine is characterized by belonging to the typology of external combustion turbines.

Four.

 According to claim 3, a device for oxygen supply and improvement of the efficiency of the ionic fuel thermo-photovoltaic engine located in a power plant, the combustible metals or aluminum or magnesium or alloy thereof being both, in which the residual heat of the air leaving The heated air turbine is captured by a heat exchanger that in turn feeds a Rankine or steam turbine circuit.

5.

 A device for oxygen supply and improvement of the efficiency of the ionic fuel thermo-photovoltaic engine located in the power plant, being the combustible metals or aluminum or magnesium or alloy of both, in which the heat of cooling of the thermo-photovoltaic cells is used to supply of energy to a turbocharger by means of a heat exchanger and a cooling circuit of the photovoltaic cells being the generation of oxygen for supply of the thermo-photovoltaic engine produced by liquefying the air in a power plant.

6.

 According to claims 5, a device for supplying oxygen to a thermo-photovoltaic motor of metallic fuel, the fuels being either aluminum or magnesium or alloy of both, characterized by using the residual heat of the air expelled from the external combustion turbine in circulating it through an exchanger of heat that supplies energy to a Rankine cycle in which a steam turbine is moved to produce energy

17 image4 image5 image6 electric through an electric generator coupled to the steam turbine shaft. Said heat exchanger also preheats the air entering the compressor of the heated air turbine.

7.

 According to claim 2, a device for supplying oxygen to a thermo-photovoltaic motor of metallic fuel, the combustible metals or aluminum or magnesium or alloy of both being characterized in that the cooling fluid is a liquid metal of high thermal transmissivity.

8.

 An oxygen introduction device in the combustion chamber of the thermo-photovoltaic motor of metallic fuel, the combustible metals or aluminum, or magnesium or alloy of both, characterized in that the mouths of the pipes that supply oxygen to the thermo-photovoltaic motor rush into its chamber of combustion in the vicinity of the photovoltaic cells, these mouths being located with symmetry with respect to the axis of revolution or with angular periodicity. The oxygen describes a vortex path towards the outlet mouth of said chamber being located in the central and lower zone of the chamber.

9.

 According to claim 8, an oxygen introduction device in the combustion chamber of a metal fuel thermo-photovoltaic engine, the metals being combustible or aluminum, or magnesium or alloy of both, characterized in that the confinement of the incandescent bulb or combustion volume is materialized to through the joint action of vortex oxygen flow and magnetic bottle created by symmetrical cylindrical magnets or electromagnets with respect to the combustion center and located on the axis of revolution of the combustion chamber.

10.

 Method for aggregation and compaction of solid wastes of thermo-photovoltaic motor of metallic fuel, being combustible metals or aluminum, or magnesium or alloy of both, consisting of the following steps:

1º.- Transport or drag of solid particles by a gaseous fluid stream under pressure. 2º.- Projection of the particles at high speed against a solid. 3º.- Evacuation and filtering and / or cycloning of the drag gas. 4º.- Compaction of the particles deposited on the solid of step 2º.

eleven.

 According to claim 10, an oxygen and solid waste evacuation device in the combustion chamber of a metal fuel thermo-photovoltaic engine, the metals being combustible or aluminum, or magnesium or alloy of both, characterized in that a suction pump (49) is located in the adjacent and lower chamber (64) to the combustion chamber (14) it creates a pressure difference with respect to that existing in the combustion chamber that motivates the oxygen entrainment of solid particles of metal oxides (40) from the chamber of combustion (14) towards the adjacent and lower chamber. A plate or surface (48) hinders the advance of solid particles allowing their deposit and precipitation on itself.

12.

 According to claim 10 and 11, a device for collecting solid particles for thermo-photovoltaic motor of metallic fuel, the combustible metals or aluminum or magnesium or alloy of both being characterized in that the pump (49) drives the flow of oxygen and smoke through a flexible conduit (51) of walls of non-stick material, said conduction ending in a narrowing or reduction of section (52), pouring the current into a vacuum chamber (21).

13.

 According to claim 10, 11 and 12, a device for collecting solid particles for thermo-photovoltaic motor of metallic fuel, the fuels being metals or aluminum or magnesium or alloy of both, characterized in that the vacuum chamber (21) is compartmentalized and equipped with minipuents crane that have sliding telescopic arms through the gantries (67) of the crane mini-bridges that allow pouring and pressing into dust aggregation compartments. Likewise, the chamber is equipped with a suction pump (57) in order to maintain various conditions and a filter (56) in the pump supply line. The pump drives the oxygen (22) to a heat exchanger (31), closing the circuit with its incorporation back into the combustion chamber of the thermo-photovoltaic reactor (14).

14.

 According to claim 11 and 12, a device for capturing solid particles for thermo-photovoltaic motor of metallic fuel, the combustible metals or aluminum or magnesium or alloy of both being characterized in that the densified powder deposit containers (48) and (58) can empty and replace voids by opening gates (61), (62) and seals (59).

fifteen.

 Device for initiating combustion in a thermo-photovoltaic motor of metallic fuel, the combustible metals being aluminum, or magnesium or alloy of both, characterized in that a C02 laser projects infrared radiation from the periphery of the combustion chamber on the metal to be burned located in the center of the combustion chamber until it is placed at combustion temperature, the light being transported from the laser to the combustion chamber by means of reflective mirrors.

16.

 According to claim 9, a combustion device in a thermo-photovoltaic motor of metallic fuel, the combustible metals being aluminum, or magnesium or alloy of both, characterized in that the combustion of metallic wire or metallic foil with the inverted and confined flame is embraced by embracing the solid residue provided cohesion as a thread or tape of magnesium oxide resulting from combustion.

17.

 Device for thermo-photovoltaic motor of metallic fuel, consisting of presenting the fuel in the form of aluminum and magnesium powder of size less than 10 microns and greater than 0.01 microns, or a microperforated sheet of thickness less than 5 microns and greater than 0, 1 micron, magnesium or aluminum or alloy of both.

18.

 Device for thermo-photovoltaic motor of metallic fuel, consisting of presenting the fuel in the form of micrometric iron grains doped with chromium or zinc, embedded in an aluminum matrix, or magnesium or alloy of both, as a tape or sheet. Either micrometric particles of either aluminum, or magnesium or alloy of both surrounding an inner core or zone of chromium and / or zinc doped iron, as a powder. For use in a power plant, chrome and / or zinc doping can be dispensed with.

19.

 Device for thermo-photovoltaic motor of metallic fuel, consisting of presenting the aluminum fuel by doping it with lithium particles.

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