FR3073899A1 - SELF-POWERED HYDROGEN ENGINE AND RELATED METHODS - Google Patents

Abstract

The invention relates to a heat engine using a mixture of air enriched with oxygen as oxidant and hydrogen as fuel, which hydrogen is produced by said engine by a high temperature electrolysis system, which temperature is supplied by the heat released by the exhaust gas, so that said engine consumes mainly water. The partial energy necessary for the operation of the electrolysis system and the compression of the gases on leaving is provided by devices driven by a turbine rotated by the outlet flow of said exhaust gas. The invention is also provided with devices for using the stopped engine electrolysis system for producing and storing said hydrogen from electrical energy supplied by renewable or non-renewable external sources. The invention is intended to become a "green" alternative to current engines, in all areas where said engines are currently used.

Description

SELF-POWERED HYDROGEN ENGINE AND RELATED METHODS.

INTRODUCTION

The awareness by users of the harmful effects of pollution and the reduction in hydrocarbon reserves has opened up the market for vehicles using low-carbon energy sources, and has encouraged world manufacturers to offer several types of motorization. hybrid, essentially consisting of an internal combustion engine associated with electric motors powered by batteries or fuel cells, and more recently with air motors, but no series model with hydrogen engine is currently offered to buyers.

Indeed, if hydrogen as an energy carrier has been used in industry for several years, notably in Power-to-Gas solutions, its use in the automotive field is not widespread, although different models using said hydrogen to supply fuel cells, have been put on the market by several manufacturers, but with a low diffusion, mainly for problems of storage difficulties, distribution, and cost, which have not to date prompted said manufacturers to develop technologies using said hydrogen.

One of the problems to which the invention proposes to provide solutions is that of the supply and storage of hydrogen, by causing the engine itself to generate the quantity of hydrogen necessary for its operation, it being specified that this generation is obtained by an electrolyser of water vaporized at high temperature by the heat given off by the exhaust gases of said engine. Part of the oxygen obtained at the outlet of the electrolyser is also added to the combustion air to improve the power of the engine.

Indeed, the progress made in recent years on the yields of electrolysers allowing the obtaining of hydrogen, and in particular those operating at high temperature, show that this production by the engine to obtain stoichiometric conditions is today possible. To obtain an explosion under conditions, the fuel concentration must be within its explosive range. In the case of hydrogen, this range is quite wide since its lower explosive limit is 4% and its upper explosive limit 75%, with a higher yield at the two extreme limits, low and high concentrations

Furthermore, with regard to the operation of the electrolyser, the exhaust gases exit at a high temperature making it possible to supply, by exchanger, the calories necessary for the operation of the electrolysis device at more than 750 °, and their flow makes it possible to entrain via a turbine the generator supplying the electricity necessary for said electrolysis.

In the variant shown here, the engine block used is of the two-stroke type, but with a built-in engine specific to the invention, particularly with regard to the power supply, and additional devices allowing said engine to operate.

For obvious reasons of production conditions, it goes without saying that the motor presented here uses the low concentrations between 4 to 11%, and the different power levels are notably obtained by varying this concentration in particular. Calculations show that the threshold of 11% hydrogen in the mixture is quite achievable for a wide range of engine revolutions / minute, and remains below what the hydrogen production device is able to deliver, i.e. a concentration in the explosive mixture of more than 20%.

These considerations mean that the energy required to manufacture the hydrogen required for the explosive hydrogen / air / oxygen mixture is much lower than that produced by the explosion of said mixture driving the engine, so that the engine is autonomous.

Even if the power required for the production of hydrogen is significant, the remaining power is available for various uses, starting with the propulsion of vehicles, the generation of electrical energy, or to transform carbon dioxide into methane.

Given that the main resource it consumes is ... water, the engine presented here is therefore particularly suitable for navigation.

Finally, the invention presented here being, as will be detailed below, equipped with means for recharging when the various tanks are stopped, said invention can be used as a means of storing electrical energy of renewable origin.

STATE OF TECHNOLOGY

The use of hydrogen as a complementary energy source in heat engines has been the subject of numerous patents, and this for more than a century.

Among these patents, which have fallen into the public domain today, we can cite the one obtained in 1801 by Philippe Lebon who files a patent for a wood gas or hydrogen gas engine as its inventor called it, or the one filed in 1804 by the Swiss François Isaac de Rivaz.

Since then, numerous patents have been filed, but have not met with the hoped-for success mainly because of the difficulties in manufacturing, storing and distributing hydrogen, despite several attempts by the main world car manufacturers.

Most of the patents filed propose solutions where hydrogen is used to improve the composition of the mixture used, this is particularly the case with documents WO 2007031848 A3, or WO 2006126341 A2, or WO 2001031188 A1 which presents a generator apparatus. hydrogen .... Few documents propose to propose solutions allowing the production in situ of hydrogen, as for example the document EP 1911957 (B1) presenting a Hydrogen engine system which proposes the use of hydrides as source, or the document WO 2010136402 A3 presenting a hydrogen engine with an autonomous production device, or the document WO 2011084637 A3 presenting a hydrogen engine with production by electrolysis by multiple piezoelectric generators.

All of these inventions have undoubtedly advanced the state of the art, but most of them do not seem to provide sufficiently simple and inexpensive solutions capable of being implemented on a large scale, weak points that the invention presented here sought to correct. DESCRIPTION OF THE INVENTION

The invention presented here is characterized in that it consists of an internal combustion engine (100) using hydrogen as fuel, and a mixture of air and oxygen as oxidant. The invention presented here is characterized in that it comprises at least one electrolysis device (200) installed on the periphery of the cylinder, as well as a set of tanks (300) receiving the hydrogen and the oxygen coming from the device. electrolysis (200) after compression, as well as the air entering the composition of the mixture. The invention presented here is characterized in that it comprises at least one device (400) actuated by the exhaust gases and generating the energy necessary to supply the electricity consumed by the electrolysis as well as that allowing the operation of the various compressors.

In the variant shown here, the engine used is a two-stroke type engine using a conventional low engine, but with a specific cylinder (110) whose combustion chamber (130) and cylinder head (140) have been modified. so that the engine is characterized in that the combustion chamber is pierced with at least one orifice (112) for low discharge of the exhaust gases, provided with at least one valve (152) for high discharge of said exhaust exhaust gas, and surmounted by at least one cylinder head (140) traversed and cooled by the water to be vaporized and receiving the valves (34x) of type (340) for injecting the gaseous mixture into the combustion chamber.

The water intended to be electrolyzed is pumped into a water tank or directly at the source in marine use, by a pump (114) driven by the motor shaft, then introduced into a steam supply circuit, which circuit brings said water out of said pump (114) to a first exchanger (425) to be then introduced passing through the cylinder head (140) through the exchanger housing (144), then towards the turns of the exchanger (116) surrounding the combustion chamber (130) where it is vaporized, to then be introduced into the electrolyser by the injection manifold (240); it being specified that the passage in the cavity of the exchanger casing (144) of the cylinder head, in addition to heating the water before vaporization, reduces the heat transfer from the cylinder to the tanks, and the presence around said cylinder of the exchanger casing ( 144) has the additional functionality of lowering, for better durability, the temperature of the cylinder (110).

To benefit from a maximum of calories and reach the necessary temperature level, the casing containing the electrolysis device (200) is directly traversed by the exhaust gases leaving the combustion chamber, by means of at least one orifice (112), when the piston (120) arrives in its low position; to complete this heating, the residue of exhaust gas compressed during the ascent of said piston (120) is reinjected at the inlet of the electrolysis device (200) by at least one valve (152) and a pipe leading to it (154). To complete the heating means, the electrolysis device (200) is also equipped with at least one superheater consisting of electrical resistors (250).

The invention presented here is characterized in that it comprises at least one electrolysis device (200) consisting of a casing (220) surrounded in its outer part by an insulating layer (210) and containing at least one electrolyser ( 230).

The invention presented here is characterized in that each electrolyser (230) comprises several electrolysis cells (232), the number depending on the power to be reached, and that the electrolysis cells are composed of anode electrodes (233 ) and cathode (235) -, an electrolyte (234) -for example with solid oxides-, and interconnectors.

The superheated steam is introduced through the injection rail (240) to the cathode (235) of the cell, as well as a small part of the exhaust gases - essentially composed of steam - through the orifice (242 ), to improve the yield of said cells, in particular thanks to the additional supply of heat.

Hydrogen is formed in this so-called cathode (235) as the electrochemical reaction progresses, and oxygen is formed simultaneously at the anode (233).

Another small amount of exhaust gas is introduced through port (244) in the anode to sweep the oxygen produced at the anode.

At the cell outlet, a hydrogen-water mixture is obtained at the cathode and oxygen mixed with water vapor at the anode.

The outgoing hydrogen-water vapor mixture (243) is condensed and then separated in a separator (480), so as to obtain an almost pure hydrogen. The hydrogen leaving the separator is then compressed by the compressor (450) to a pressure suitable for the intended use of the engine.

The oxygen stream mixed with water vapor (245) leaving the anode is treated by cooling / condensation to separate it from the residual water vapor in the separator (490), and is then compressed by the compressor (460) to a pressure adapted to its proportion in the mixture.

On leaving their respective separator, each of the gases making up the mixture is, after compression, stored in the buffer tanks ((31H, 31O, 31A) under differentiated pressures in relation to their share in the mixture. 'execution presented in the figures, said buffer tanks are installed above the cylinder head, but other arrangements are possible.

To ensure the safety of the assembly, the hydrogen, oxygen and air stored in the buffer tanks (31 H, 310.31 A) and necessary for the operation of the engine are not introduced directly into the combustion (140) driving the piston (120), but the quantity of each of the gases making up the final mixture is prepared in a prechamber specific to each gas (33H, 33O, 33A), said prechamber being supplied from each of the reservoirs- buffer.

In the version shown in the figures, said pre-chambers are installed above the combustion chamber of the cylinder but are isolated from the engine block by a casing (144) or the water to be electrolyzed circulates, with, as indicated above, a dual purpose, cooling said buffer tanks, and heating the water before its vaporization for electrolysis.

The invention presented here is characterized in that it comprises at least one device (400) constituted in the alternative embodiment presented in FIG. 1, of at least one turbine (420) set in rotation by the gases exhaust leaving the combustion chamber through the exhaust crown (410) after passing through the electrolysis device (200), and coupled to a centrifugal clutch device (430) which drives at least one generator (440 ) reversible in motor producing the electrical energy necessary for the proper functioning of the electrolysis device (200), as well as at least one disengageable compressor for each of the gases to be compressed - hydrogen (450), oxygen (460) and air (470 ) - whose compression ratio is suitable for the use of each gas; it being specified that before their compression the mixtures of hydrogen and water vapor as well as those of oxygen and others are condensed to be purified in their respective separator (480,490), is that the water leaving said separators is reintroduced into the water reserve.

The utility of the centrifugal clutch (430) is, in the disengaged position when the engine is stopped, to be able to use the reversibility in engine of the generator, to drive the three compressors by an external electrical source.

The different gases stored in the buffer tanks are transferred to the pre-chambers by means of double inverted valves (314,334) controlled by a device (320) regulating the quantity to be introduced per cycle, as a function of the concentration of each gas adapted to the engine operating conditions, for example number of revolutions and power demanded. Said device consists of a T-shaped lever (322) rotating around its axis (323) and set in motion back and forth by means of a rotary cam (324) rotating around its axis (325) and driven by the rotation of the motor shaft. The tilting of the lever (322) causing the simultaneous opening / closing of the valves (314,334) is obtained by the support of the appendage (326), compressible via a spring (327), of the cam on said lever; the degree of opening of the valves by this lever being controlled by the sliding rod (328), the depression of which limits the tilting of said lever, thus making it possible to adjust the amount of each of the gases introduced as a function of the operating conditions of the engine, in the pre-chambers upstream before their introduction towards the main chamber of the cylinder (130) through the outlet orifices (146).

Finally, the transfer of the various gases introduced into the pre-chambers (33x) to the main chamber (130) of the cylinder is carried out through valves (340) rotating around their axis (342) whose positioning is driven by the engine; it being specified that the orientation / inclination of the outlet orifices (146) is chosen to obtain good homogeneity of the mixture before it explodes.

Given these devices, the engine works as follows:

A- to avoid the use of high capacity batteries, the engine is started by a pneumatic starter - not shown - using the stored compressed air, which starter is engaged on the starter ring by a pneumatic device.

B- after starting, the engine operates as follows in eight phases:

- Phase 1: as soon as the piston reaches its high position and the chamber (130) has been emptied of its residual exhaust gases, the gases present in the pre-chambers (33x) are discharged by the simultaneous opening of the three valves ( 34x).

- Phase 2: the piston (120) begins its descent, and the upper part of the main chamber of the cylinder (130) is filled by the mixture and the pressure of the pre-chambers (33x) and that of the top of the main chamber of the cylinder s 'balanced.

- Phase 3: the three valves (34x) controlling the unloading of the pre-chambers to the main cylinder chamber are then closed.

- Phase 4: the discharge of the spark from the spark plug (160) intervenes and triggers the explosion of the mixture, which causes the piston to descend, until its head reaches the exhaust orifices (112) and allows the exhaust of gases through the casing (220) of the electrolysis device.

- Phase 5: during this descent, the opening of the inverted valves (314,334) allows the transfer of the different gases stored in the buffer tanks (31 x) to the pre-chambers (33x).

- Phase 6: the piston descends to reach its bottom dead center then starts to rise

- Phase 7: as soon as the piston has exceeded in its rise the level of the exhaust orifices (112) and that said orifices are closed, the secondary exhaust valves (152) are opened until said piston (120 ) is approaching its highest point.

- Phase 8: during this ascent of the piston, the inverted valves allowing the transfer of the various gases stored in the buffer tanks to the pre-chambers are closed, then before the piston reaches its high point, the secondary exhaust valves (152) are also closed, and the cycle starts again in phase 1.

C- The accelerations / decelerations of the engine are mainly obtained by modifying the concentration of oxygen in the mixture and / or the quantity of gases introduced.

To illustrate this operation, FIG. 1 provides a schematic representation of the various components constituting the invention, in a single cylinder variant execution adapted to understanding said operation, it being specified that in other variant variants several cylinders can be interconnected in different existing configurations for conventional engines, and that in the configurations where the cylinders are joined, the devices can be incorporated in the engine block.

Said figure shows a single cylinder variant with three supply assemblies, one for each of the gases used, hydrogen (30H), oxygen (300) and air (30A), each assembly consisting of a buffer tank (31 x) below which is installed a prechamber (33x) connected by an intermediate device (32x) ensuring the transfer, by means of double reverse valves (314,334), of the gas coming from said buffer tank to said prechamber (33x). These devices are installed above the cylinder head (140) and connected to said cylinder head by a casing (144) where the valves (34X) - of spherical type in this version of execution - for transferring gases from the prechamber towards the combustion chamber, said casing (144) also being traversed by water intended to supply steam to the electrolysis devices, said water supplied by the pump (114); said device having advantageously been designed to preheat said water and simultaneously cool said pre-chambers.

Also visible in the figure and in this alternative embodiment is the spark plug (160) and four secondary exhaust valves (152) open in phase 5 and channeling (154) the outlet of the residual exhaust gases towards the low entry of the electrolysis device (200).

In the variant shown, there are installed, at the periphery of the cylinder body (110), eight electrolysis devices (200) surrounded by a layer of thermal insulating material (210), and surmounted by a crown (410) recovering the exhaust gases from passing through the electrolysers, to send them to the turbine (420).

FIG. 2 provides a schematic representation of the various components constituting an electrolysis device in the alternative embodiment presented in FIG. 1.

The various devices constituting the means for storing and transferring the gases to the combustion chamber are presented in FIG. 3, devices the operation of which is described above; it being specified that the configuration adopted was to avoid any propagation in the event of a leak by the transfer valves (34x) when the mixture was ignited by the spark plug.

To ensure in particular the initial starting of the engine and / or its operation before obtaining the high temperature necessary for the proper functioning of the electrolyser, and / or to be able to have a power reserve, the engine here presented is also equipped inside the device (400) of means allowing recharging, at a standstill and by any source of electrical energy, separate buffer tanks of hydrogen, oxygen and air, tanks to which in this use can be optionally added to other larger auxiliary tanks.

Said device is made up of elements making it possible, in this configuration, to use any renewable energy source, solar or wind, or simply the domestic electrical network, to supply the electrical intensity necessary for the electrolyser, to obtain the temperature necessary for its operation by switching on the superheater included in the electrolyser, and ensuring the drive of the compressors provided by the reversible generator (440) then operating as a motor, or by an additional electric motor.

The invention is characterized in that it comprises means for controlling, regulating and piloting the devices, the said means being in particular made up of at least one computer integrating means in particular made up of all of the algorithms and computer programs. able to manage its control according to the information provided by the various pressure, temperature, number of revolutions, and other information characterizing the operation of the engine.

The invention is in no way limited to the embodiments described and presented in the various figures, which are illustrated and given only as examples of possible alternative embodiments. The characteristics, objects and advantages of the present invention presented here are only by way of nonlimiting examples.

FIGURES

The accompanying drawings illustrate the invention.

Figure 1 shows a schematic view of the main elements constituting the invention.

FIG. 2 represents a schematic view of the electrolysis devices.

FIG. 3 represents a schematic view of the various devices constituting the means for storing and transferring the gases in the combustion chamber.

Claims (10)

1- Invention characterized in that it comprises means capable of delivering motive force, said means consisting of an internal combustion engine (100) using hydrogen as fuel and a mixture of air and oxygen as oxidizer, at least one high electrolysis device (200) 5 temperature, of at least one device (300) for storing and injecting the gases produced by said electrolysis device, of at least one device (400) capable of delivering energy for the operation of the device electrolysis (200) and gas storage (300), as well as means for controlling, regulating and piloting said devices. 2- Invention characterized according to claim 1 in that it comprises an internal combustion engine 10 (100) using hydrogen as fuel and a mixture of air and oxygen as oxidant, which engine is characterized in that the combustion chamber is pierced by at least one low exhaust orifice (112) exhaust gas, provided with at least one valve (152) for discharging said exhaust gas at the top, and surmounted by at least one cylinder head (140) traversed and cooled by the water to be vaporized and receiving the valves (340) injection of the gas mixture into the combustion chamber. 15 3- Invention characterized according to claim 1 in that it comprises at least one high temperature electrolysis device (200) consisting of at least one circuit for supplying the water to be vaporized and at least one casing (220) through which the exhaust gases pass, inside which at least one water vapor chlorinator (230) is installed. 4- Invention characterized according to claim 3 in that it comprises at least one supply circuit 20 of the water to be vaporized, which circuit consisting of a pump (114) bringing said water to a first exchanger (425) to then be introduced into a casing (144) and then to the turns of the exchanger (116) surrounding the combustion chamber (130), to then be introduced into the electrolyser by the injection rail (240). 5- Invention characterized according to any one of the preceding claims in that it comprises 25 electrolysis means consisting of an outer casing (220) protected by an insulating layer (210) and inside which is installed at least one electrolyser (230) brought to high temperature by the exhaust gases passing through said casing at the outlet of the combustion chamber through one of the orifices (112), as well as by at least one superheater consisting of electrical resistors (250) and characterized in that each electrolyser (230) comprises several electrolysis cells (232 ) composed of anode electrodes 30 (233) and cathode (235), an electrolyte (234) and interconnectors, and in that the water vapor is introduced into it by the ramp (240) and that part of the exhaust gases is also introduced therein through the orifices (242 and 244), and in that said casing is surmounted by at least three pipes through which the oxygen (245) and the hydrogen (243) produced by the electrolyser exit, thus that that per which the exhaust gases collected by the crown (410) exit. 35 6. Invention characterized according to any one of the preceding claims in that it comprises means for purifying and compressing the gases produced by the electrolysis device, means constituted for each gas by separators (480,490) and compressors ( 450.460). 7- Invention characterized according to any one of the preceding claims in that it comprises at least one device (300) for storing and injecting the gases produced by the electrolysis device, and that said device consists of reservoirs- buffer of hydrogen, oxygen and air gases (31 H, 310.31 A) necessary for engine operation; and specific chambers for each gas (33H, 33O, 33A) and supplied from each of the buffer tanks, and in that the transfer of gases from the buffer tanks is ensured by an intermediate device (32x) regulating the quantity to be introduced by cycle and consisting of double inverted valves (314,334) controlled by a T-lever (322) rotating around its axis (323) and set in motion back and forth via a rotary cam (324) rotating around its axis (325) and whose tilting causes the simultaneous opening / closing of the valves (314,334) by the support of the appendage (326), compressible via a spring (327), of the cam on said lever; the degree of opening of the valves by this lever being controlled by the sliding rod (328), the depression of which limits the tilting of said lever, thus making it possible to adjust the amount of each of the gases introduced. 8- Invention characterized according to any one of the preceding claims in that it comprises to ensure the transfer of the different gases introduced into the pre-chambers (33x) to the main chamber (130) of the cylinder of valves (340) rotating around their axis (342) and bringing said gases to the main chamber (130) through the outlet orifices (146) 9- Invention characterized according to claim 1 in that it comprises at least one device (400) capable of delivering energy for the operation of the electrolysis device (200) and of compression and storage of gases ( 300), which device consists of at least one turbine (420) rotated by the exhaust gases leaving the combustion chamber by the exhaust ring (410) after passing through the electrolysis device (200 ), and coupled to a centrifugal clutch device (430) which drives at least one generator (440) reversible as a motor producing electrical energy for the proper functioning of the electrolysis device (200), as well as the various compressors (450), (460) and air (470). 10- Invention characterized according to any one of the preceding claims in that it comprises means for controlling, regulating and piloting the devices, the said means being in particular made up of at least one computer integrating means notably made up of the '' set of algorithms and computer programs able to manage its control according to the information provided by the various pressure, temperature, number of revolutions, and other information characterizing the operation of the engine.