TEXT OF THE DESCRIPTION

The present invention relates to a system for fuel/fuel mixture supply for internal combustion engines, and specifically relates to a system that uses electrolytic generation of oxyhydrogen gas, i.e., the stoichiometric mixture of hydrogen and oxygen, from an aqueous salt solution.

The use of water as a source of hydrogen fuel is a research goal that has been approached several times over the years; on the one hand, hydrogen's high calorific value and the speed of propagation of its combustion could guarantee important results, on the other hand, it is necessary to manage precisely the flammability and very low density of the gas, which therefore requires high volumes to ensure adequate energy yields.

Document IT102015000075171 describes a device for combustion efficiency enhancement of fuels, solid liquid or gaseous, that uses oxy hydrogen gas generated in an electrolytic cell. In this case, the electrolytically produced gas mixture is used to improve the combustion of fossil fuels such as gasoline and diesel fuel, but the possibility of powering the engine predominantly with hydrogen combustion is not considered.

Document WO2015079316 describes an internal combustion engine powered by an electrolytic cell that generates oxyhydrogen gas in relation to the fuel demand of the engine supply; gas production is controlled by a processor that controls an amplitude-modulated pulse generator suitable for controlling the operation of the cell.

Document EP3124781 describes a propulsion system for a ship that uses oxyhydrogen generated in an electrolytic cell to improve the combustion efficiency of fossil fuel, particularly diesel fuel.

Beyond the production capacity of the system, and its operational safety, which remain primary concerns in any case, it must be faced that electrolysis, when conducted at the operating voltages normally used in internal combustion engines, leads to an extremely large power draw relative to that of the engine, thus making the energy balance of the system disadvantageous.

Thus, the aim of the present invention is to provide a fuel system of the type described above that is capable of overcoming the problems encountered in the past, and that ensures the supply of oxyhydrogen gas to the internal combustion engine in a manner properly proportioned to its needs, while allowing energy yields such that the economics of the process are justified.

It is therefore an object of the present invention to provide a fuel system for internal combustion engines with electrolytically produced oxyhydrogen gas, comprising at least one electrolytic cell, connected with an aqueous salt solution supply tank, and connected to means for supplying direct electric current, the oxyhydrogen gas resulting from the electrolysis being collected in a suitable collector and sent, at a given pressure, into a temporary storage tank, and from this sent to the inlet of an internal combustion engine, said engine being provided with a conventional fossil fuel supply system, a processing unit being provided capable of controlling the electrolysis process according to the operating speed of the engine, and connected to means of sensing the pressure of the temporary storage tank, and a connection being provided, suitably controlled, between the discharge of the internal combustion engine and an exhaust pipe of the temporary storage tank of the oxyhydrogen gas; the electrolytic cell is electrically supplied with direct current at a voltage between 2.5 V and 5.5 V, and preferably between 3.0 V and 3.5 V, and at an intensity between 20.0 A and 30.0 A.

Advantageously, the electrodes of the cell are a plurality of steel plates, equally divided between anodes and cathodes, ranging in size from cm 10.0 to cm 25.0 in height and cm 10.0 to cm 25.0 in width, with a thickness between mm 0.25 and mm 0.75; preferably 120 to 240 plates are provided in each cell.

Particularly, the plates are rectangular, and have through-holes near two opposite vertices, and concavities at the remaining two vertices; the plates are connected to each other by threaded rods, and appropriately spaced apart. The anode plates are connected to each other, as are the cathode plates, and means of connection also allow the distance between the plates to be adjusted. In an executive variant, the temporary oxyhydrogen gas storage tank is provided with a vacuum suction line, a safety discharge line, and an excess stored gas discharge line, each line being provided with appropriate valve control means, and said lines being connected with the combustion gas exhaust line of the internal combustion engine.

In another embodiment, the circuit for supplying the aqueous saline solution involves a tank connected by a pump to a distribution unit comprising an upper compartment separated by a septum, provided with an opening controlled by a float valve, from a lower compartment, said lower compartment being communicating with the electrolytic cell supply line, and an opening being provided in said upper compartment, upstream of the septum, communicating with a line that returns excess water to the tank.

Further advantages and features of the system according to the present invention will be evident from the following detailed description of the attached tables of drawings, in which: figure 1 is a schematic block diagram depicting an embodiment of the power system according to the present invention;

Figure 2 is a plan view of an embodiment of the electrodes of the power system cell according to the invention; and

Figure 3 is an enlarged detail of a side elevation view of an embodiment of the electrodes illustrated in Fig. 2.

Figure 1 shows the block diagram of an embodiment of the system according to the present invention, in this case referring to an engine operating as the propulsion system of a motor vehicle; with 1 are designated two electrolytic cells, each provided with the plates 101, which form the electrode surface of the cells, and will be better illustrated and described later, the power supply of which is controlled by the central control unit 202, connected to the alternator 102 of the internal combustion engine 2 and to the engine itself; the unit 202 is also connected to the battery 302. The oxyhydrogen gas generated in the cells is routed from lines 10, 10' into manifold 201, and from there onto lines 11 and 12, via valve 211 and pump 301, to temporary storage tank 401, the pressure of which is controlled by central control unit 202 via pressure sensor 601. Internal combustion engine 2 is supplied by line 13 from temporary storage tank 401 of oxyhydrogen gas, as well as line 30 from fossil fuel tank 3, e.g., gasoline. Tank 401 is connected to a vacuum suction line 14 in which a pump 411 sucks in the contents of tank 401, an emergency exhaust line 15 manned by a safety valve 501, and an excess gas exhaust line 16, controlled by valve 431; all three lines, via valve 451, communicate with exhaust line 20 from internal combustion engine 2. The electrolytic cells 1, T are supplied with aqueous salt solution contained in tank 4, which through pump 104 on line 40 feeds the inlet conduit 274 of distribution organ 204, separated into two compartments by septum 214 provided with opening 224 controlled by float valve 234, arranged in guide 244; the compartment in which the valve is located has conduit 254 communicating with line 42 supplying the cells, while upstream of septum 214 is provided conduit 264 recirculating water to tank 4.

Figure 2 shows an embodiment of the electrolytic cell plates used in the system according to the invention; 101, 101' are designated two consecutive plates, which have the same shape and size; plate 101 has near two vertices opposite each other in the center the through holes (not shown) in which the threaded rods 121, on which the bolts 131 are arranged, are inserted, while at the other two vertices the concavities 111 are formed. Similarly, plate 101' has, at the vertices to which concavities 111 of plate 101 are superimposed, through holes in which threaded rods 12 T are placed, on which bolts 131' are secured.

The arrangement of plates 101, 101' is best evident from Figure 3, in which equal parts correspond to equal numerals. As can be seen from the figure, plates 101, which can be designated as anodes, are spaced and electrically coupled to each other via bolts 131 and threaded rods 121, while plates 101', the cathodes, are coupled and spaced via bolts 131' and threaded rods 121'. The 131, 131' bolts are of the same thickness, and the distance between each anode plate and the corresponding cathode plate is essentially equal to half the height of the respective spacer bolt. The plates at the ends of the cell, as well as some of the inner plates, are connected to the 202 control unit, so that the cell is always properly energized, so as to prevent flexing in cell productivity. This solution, as highlighted in the figure, is completely modular, and can accommodate a wide variety of plate sizes, which are extremely stably connected to each other. Advantageously, the plates are all made equal to each other, and the structural expedient lies in flipping one plate over the previous one so that the concavities alternate in the manner evident in Figure 3.

The operation of the system according to the present invention will appear evident from the following. With this system, the engine is totally supplied by Oxyhydrogen Gas also called Brown's Gas, produced in real time by electrolytic cells installed on board the car, and/or near the engine for those stationary. Its production is always what the engine needs at its maximum speed, while at lower speeds it is in surplus and therefore the surplus gas is released into the atmosphere through the exhaust.

The engine will always start using fossil fuel and then switch to gas as soon as the operating pressure is reached in the temporary storage tank 401. If for any reason, even during normal running, the pressure in tank 401 drops to +0.5 bar there will be an automatic switchover from gas to fossil fuel.

The system includes a multifunctional 202 electronic control unit that manages all system functions; power supply and operation of the electrolysis cells 1 are managed by the control unit. The system also includes a tank 401 for collecting the produced gas in real time; a vacuum pump 411; a pressurization pump 301; a PT 601 (pressure transmitter) with range -0. 5/+7 bar; a PCV 431 (pressure control valve); a PSV 501 (safety valve); two solenoid valves 211 and 451 sealing ball valves, mounted respectively, one on the pipe carrying the gas from the cells to tank 401, the other mounted on the line going to the exhaust line 20, both of which close automatically when the engine is turned off; four check valves mounted respectively: one (311) between pressurization pump 301 and tank 401, one (441) mounted downstream of PCV 431, one (421) mounted downstream of vacuum pump 411, and one (521) downstream of PSV 501; an arrestor 21 (flame arrestor system) mounted on discharge line 20.

The electrolytic cells for gas production are electrically powered at 3.0 volts DC 30.0 Ampere; power is supplied by CPU 202. The number of cells is variable to ensure gas production to the technical features of the engine to be powered (displacement, power, etc.). They are housed under the load floor of the rear trunk about 20/22 cm outside the car with access from the trunk. This also offers the possibility of being able to create leakage routes in case of accidental gas leaks, moreover without affecting the car's load capacity.

The gas produced is collected with rubber hoses and brought to a PVC collector 201 to which is connected a solenoid valve 211 with a sealing ball and a steel pipe of suitable diameter which, coming out and anchored to the car floor, re-enters the engine compartment to connect with the pressurization pump 301 which, in addition to pumping the gas into the tank 401, also promotes its flow, from which it goes to feed the engine 2. The tank 401 is a vessel whose capacity must be such as to meet the needs of the engine at all times. Mounted on it are the PT 601, the PCV 431, or self-regulator, the vacuum pump 411, and the PSV 501, which with its intervention by high pressure empties the circuit and interrupts gas production by switching the power supply to gasoline. The gas pumped into the 401 tank generates a pressure (which will also be monitored in real time on the dedicated dashboard or gauge), this allows us to optimize the supply to the engine and gives us the system that, by controlling the pressure, ensures that the amount of gas needed by the engine is controlled in real time and the surplus gas is expelled.

The pressure control loop is the PT 601 which sends a signal to the electronic control unit which in turn controls the PCV 431, not if the PCV is a self-regulator. The pressure control set will be approximately 2/3 bar to be better defined according to the features of the engine in use. The gas expelled from the PCV 431 will be released to the atmosphere through exhaust line 20.

Obviously in tunnel transit it is not possible to exhaust, and therefore all electronic control units will have to be equipped with a system for receiving GPS signals to signal to the control unit that a tunnel entrance is approaching, which will perform the gas/fuel exchange, also closing the 211 solenoid valve on the gas line and stopping the 301 pressurization pump and electrically de-energizing the cells as well, to restore all functionality at the tunnel exit.

A lighted button located in the passenger compartment, which is easy to see and access, will make it possible to bypass the GPS signal and thus switch to gasoline power in cases of necessity, such as at entrances to underground garages or private garages. Of course, for stationary engines the problem does not arise.

If when the engine is started (which will always be on gasoline), the pressure in tank 401 is found to be +0.2/+0.3 bar, solenoid valves 211, 451 open, the cells are fed electrically and gas production begins, the pressurization pump starts, and when the maximum pressure setting value is reached in tank 401, and then gasoline/gas switching takes place.

On the other hand, if the pressure is found to be "0" bar, the vacuum pump 411 is started and only the sealing solenoid valve 451 on the line leading to the discharge line is opened. When -0.2/-0.3 bar is reached, pump 411 is stopped and the same procedures described above are implemented.

The electrolytic cell consists of a variable number of electrodes made up of 101, 101' stainless steel plates about 0.5 mm thick assembled and spaced 1 to 2 mm apart, in the manner illustrated in Figures 2 and 3, and electrically powered by means of the control unit 202. A relevant aspect is related to the low supply voltage of the cells, between V 2.5 and V 5.5, and particularly between V 3.0 and V 3.5, while maintaining a consistent current intensity, between A 20.0 and A 30.0; this choice makes it possible to contain the power absorption by the electrolytic process, thus limiting the loss of engine efficiency.

Each cell 1 is placed in an anti-corrosive container always filled with distilled FEO with a small amount of potassium hydroxide dissolved (2.5 g/1) to about 30.0 mm above the level of the plates plus another 30.0 mm of room to the cover to facilitate gas formation. This system refers to a cell consisting of 100 cathodes and 100 anodes.

Specifically, a cell of 200 elements (100 cathodes and 100 anodes) with dimensions mm 105.0 high, mm 250.0 wide and mm 0.5 thick, develops a total area of the two faces equal to 10.5 m ² with a gas production of 0.40 liters per second.

The final overall dimensions are 40 cm (length) x 25 cm (width) x 20 cm (height). Of course, varying the size of the plates or their number varies the overall dimensions, the amount of gas produced and the power engaged accordingly. The loss of engine power committed to gas production is largely recovered by the extra number of octanes hydrogen has (138 octanes) compared to gasoline (94 octanes).

The hydraulic system consists of a steel tank 4 with filling from the outside, located under the rear seat, next to the one for gasoline, which for obvious reasons will become smaller. It will be filled with demineralized water with potassium hydroxide dissolved in it. It will be equipped with transfer pump 104 (always in operation) and level switch for indicating the status of the level and reserve, a distribution organ 204 made of anti-corrosive material with a capacity of about 3-4 liters, a filter 284 that will be mounted at the inlet of the same. It is divided into two compartments, one upper and one lower, with respect to a septum 214 provided with an opening 224. The upper chamber has an inlet 274 for the arrival of water from the main tank, an outlet 264 for the return to the tank. The lower chamber in turn has outlet 254 that goes to feed the cells.

The lower chamber has a tube 244 welded in the middle at the bottom for a height of slightly more than half the chamber and a diameter to allow sliding to the float 234, the tube also will be perforated all around to allow water circulation. Float 234 has a conical-shaped plug with the tip pointing toward opening 224, and thus displacement of the float will allow or inhibit the passage of water, thereby regulating the cell supply.

The system according to the invention, which in the executive example given has been referred to use in motor vehicles, can of course be adapted to both boat propulsion and power generation in medium- and large- scale plants, without departing from the scope of protection as defined above and detailed below in the appended claims.