Method for operating an internal combustion engine with a gas mixture produced by water electrolysis and supplied to the combustion air, as well as arrangement and electrolysis device for carrying out the method

Description

The invention relates to a method for operating an internal combustion engine with a gas mixture produced by electrolysis of water and supplied to the combustion air, as well as to an arrangement with an electrolysis device for carrying out the method.

In one of the EN 10 2009 026 374 A1 In the known method for operating an internal combustion engine for motor vehicles with fossil fuel and a hydrogen-oxygen mixture (oxyhydrogen gas, brown gas) produced in the vehicle by electrolysis of water and fed to the combustion air in the intake tract of the engine, the hydrogen-oxygen mixture is generated and temporarily stored during normal engine operation until a predetermined storage pressure is reached and is only fed into the intake tract of the engine when the engine is running at high power when the vehicle is starting and accelerating. The hydrogen is generated using a complex electrolysis device supplied from a separate water tank that is connected to an additional alternator.

The WO 2007/ 091 105 A1 describes the use of a hydrogen-oxygen mixture produced in an electrolysis device in a combustion engine powered by conventional fuel, whereby the fuel is temporarily replaced in whole or in part by the hydrogen-oxygen mixture produced in the vehicle when the load changes. WO 2007/ 101 329 A1 A method and a device for hydrogen-assisted cold starting of an internal combustion engine are known. The oxygen is to be separated from the hydrogen-oxygen mixture produced in an electrolysis device. US 6 155 212 A and in the WO 2006/ 124 805 A2 describes the additional use of hydrogen generated and temporarily stored in the motor vehicle for the combustion process.

One from the EN 10 2008 003 126 A1 A known electrolysis device connected directly to the combustion chamber of an internal combustion engine via the intake tract to produce a hydrogen-oxygen mixture to be added to the fuel uses potassium hydroxide (KOH) as an electrolyte to improve the efficiency of the electrolysis. The electrolysis device comprises evenly spaced electrode plates that are immersed in the electrolyte in a container. The two outer plates are connected to the negative and positive poles of the vehicle battery and the number of plates is determined according to the voltage provided by the battery so that a voltage of around two volts is present between two opposing electrode surfaces for the electrolysis to be carried out.

In the US 2010 / 0 175 941 A1 describes an apparatus for a signal generating device that generates an electrical signal for use in an electrolysis device.

In the US 4 936 961 A describes a method for obtaining the delivery of a gasoline-gas mixture which also includes hydrogen and oxygen.

In the WO 2015/ 021 385 A1 An electronic control unit and a method for regulating the release of hydrogen and oxygen are described.

The invention is based on the object of designing a method for operating an internal combustion engine with a gas mixture produced by electrolysis of water and fed to the combustion air, as well as an arrangement and an electrolysis device for carrying out the method in such a way that, with little equipment and energy expenditure and with low electrolyte consumption, a quantity of gas sufficient for efficient fuel combustion is continuously generated and fed into the engine combustion chamber in such a way that reduced fuel consumption and simultaneously reduced pollutant emissions are ensured. According to the invention, the object is achieved with a method according to the features of patent claim 1 and with an arrangement and an electrolysis device according to the features of patent claim 6.

Appropriate and advantageous developments of the invention are the subject of the subclaims.

When operating an internal combustion engine with a gas mixture that is additionally supplied to the fossil fuel in the engine combustion chamber, produced by an electrolysis device assigned to the internal combustion engine and introduced into the combustion air, the core of the invention is that the amount of air sucked into the intake tract of the engine according to the respective engine operation or engine power, for example when idling, accelerating, etc., is measured and per unit volume of combustion air sucked in, always an equal, limited amount of Brown's gas, which only functions as an additive and contains hydrogen, oxygen and energy-enriched gaseous water molecules and is produced with the electrolysis device with a pulsating current, without intermediate storage. tion, i.e. while the high-energy and ignitable, but only short-term stable gaseous water molecules (also known as linear water isomers) are still being formed, the combustion air is fed in. The percentage of the electrolytically generated gas mixture present in the fuel during the combustion process is so limited that the hydrogen molecules distributed in the fuel-air mixture in the engine combustion chamber only act insignificantly as additional fuel, but only the energy-enriched, gaseous water molecules in the Brown's gas serve as starting or ignition nuclei that ignite the fuel quickly and explosively for an earlier onset and long-lasting intensive and complete combustion.

The fossil fuel (for example diesel or petrol) is used more efficiently simply because of the energy-enriched gaseous water molecules in the Browns gas, which only act as ignition seeds, so that the engine performance can be improved and fuel consumption and thus pollutant emissions can be reduced. In addition, the exhaust gas temperature and thus the nitrogen oxide and carbon dioxide emissions are further reduced. The equipment and energy required for the continuous provision of the Browns gas by the electrolysis carried out according to the invention is low because of the controlled production of a limited amount of gas depending on the intake air quantity and because of the increased gas production in the electrolysis device due to the pulsating current. The power consumption for the electrolysis is minimized in such a way that the required electrical energy - without an additional or larger alternator - can be supplied by the vehicle battery alone. The extremely low brown gas requirement of 0.05 to 0.5 per mille per liter of intake air is also advantageous in that the required amount of gas can be constantly made available with a small electrolysis device without intermediate storage.

In a further embodiment of the invention, the current pulses acting on the electrolysis device are rectangular or trapezoidal in shape.

In an advantageous development of the invention, the current pulses are generated continuously or at intervals and with different amplitudes to influence the amount of brown gas produced and in particular the proportion of energy-enriched, gaseous water molecules contained therein. The gas yield can also be influenced by the choice of the flank angle of the current pulse length.

In a further development of the invention, the current pulses are controlled depending on the electrolyte temperature and the electrolyte concentration as well as the plate geometry and the plate spacing in such a way that the system consisting of electrode plates and electrolyte is operated in resonance. This leads to a flushing of the electrode plates and to a rapid detachment of the gas bubbles and thus also to an increase in the gas yield.

According to another important feature of the invention, the amount of brown gas produced in the electrolysis device is controlled depending on the respective engine operation on the basis of the amount of air supplied to the intake tract, as measured by an air mass meter, in conjunction with the amount of brown gas actually produced by the electrolysis device, as measured by a flow meter. This means that essentially only as much brown gas is produced in the electrolysis device as is currently required in the respective engine operation, so that the power consumption is low and the capacity of the vehicle battery is not used more than necessary.

The arrangement for carrying out the method, which comprises an air supply line starting from an air filter box and connected to the engine combustion chamber of the internal combustion engine for supplying an air quantity adapted to the respective engine operation, is characterized according to the invention in that a gas supply line connected to an electrolysis device supplied by a vehicle battery opens directly into the air supply line, and an air mass meter for detecting the volume of air sucked in depending on the respective engine operation is integrated into the air supply line before the opening of the gas supply line and a flow meter for detecting the actual amount of gas generated and a throttle valve for finally setting the gas volume adapted to the amount of air delivered are integrated into the gas supply line in the direction of flow, each of which is connected to a first control device assigned to the electrolysis device for regulating gas generation on the basis of the amount of air sucked in and the amount of gas detected with the aid of a pulsating current that is converted continuously or at intervals by a modulator and is variable in frequency, amplitude, edge rise angle and duration.

In a further embodiment of the arrangement according to the invention, a water separator, a water detector and a gas filter for gas purification and a burn-back protection consisting of a gas-permeable ceramic material to prevent flashback are integrated into the gas supply line in the electrolysis device.

In an embodiment of the invention, the first control unit is connected to a main control unit assigned to the internal combustion engine via a second control unit. The first and second control units can also be integrated into the main control unit.

In a further embodiment of the invention, the gas supply line opens into the air supply line via a Venturi nozzle arranged downstream of the air mass meter in order to swirl and evenly distribute the gaseous water molecules contained in the gas flow in the intake air.

In an advantageous development of the invention, the electrolysis device has several electrode plates arranged parallel at a distance and provided with openings in a housing filled with an electrolyte. The two outer electrode plates or alternatively a central electrode plate and the two outer electrode plates are connected to the positive or negative pole of the vehicle battery via the first control unit. A gas collection chamber, which is delimited above the electrode plates by a housing cover and briefly absorbs the brown gas generated, can be connected to the gas supply line leading to the air supply line via a cover that can be attached to a gas outlet nozzle in a sealing manner and opens automatically at a certain overpressure (approx. > 0.1 bar) in the gas collection chamber, with an internal pipe section that accommodates a filter and a gas connection nozzle. The small gas reservoir above the electrode plates, which is under low pressure, enables the high-energy, gaseous water molecules, which are only stable for a short time, to be quickly fed to the combustion air.

In an embodiment of the invention, the housing cover of the electrolysis device has a section that is lowered to the maximum electrolyte filling level in the housing and has a filling opening that can be closed with a screw cap. Overfilling the electrolysis device or excessive dilution of the electrolyte is thus impossible and a certain gas reservoir is always available above the electrolyte.

In a further embodiment of the invention, the electrode plates are fixed in grooves provided on the bottom and two opposite side walls of the housing as well as in the area of the upper edge of the electrode.

In an advantageous development of the invention, the electrolysis device for monitoring the electrolyte comprises a density meter, a level meter and a temperature sensor as well as a pressure relief valve.

In an embodiment of the invention, the electrode plates have a width that is significantly greater than their height. This means that a sufficiently large electrode surface is covered with electrolyte over a long period of time, thus ensuring a long operating time of the electrolysis device without having to refill electrolyte.

The electrode plate thickness is about one millimeter and the electrode plate distance is between 1.5 and 10.5 millimeters. The electrolyte in the electrolysis device is preferably a 3.5 to 5.0 percent potassium hydroxide solution.

In a further embodiment of the invention, the electrolyte has an increased concentration for lowering the freezing point in winter operation and/or contains up to a maximum of 10% ethylene glycol as an antifreeze.

In the 1 The arrangement shown comprises, as conventional components, an internal combustion engine (for example for a passenger car), represented here only by the engine combustion chamber 1, the individual cylinders of which are connected via an intake manifold 2 to the intake tract for the combustion air sucked in due to the piston movement. The intake tract essentially consists of an air supply line 4 extending from an air filter box 3, into which an air mass meter 5 for recording the volume of air sucked in depending on the engine operation, as well as a turbocharger 6 for compression and a throttle valve 7 for regulating the amount of air supplied to the intake manifold 2 in accordance with the engine power required in each case are integrated. The amount of fuel supplied to the engine combustion chamber 1 is regulated via a main control unit 8 (OBD control unit) assigned to the internal combustion engine and connected to the air mass meter 5.

The internal combustion engine is connected in the usual way to a vehicle battery 9. The alternator 10 is coupled to the generator to supply power to the electrical devices and other power consumers required for the operation of the internal combustion engine. The power provided by the vehicle battery 9 via a fuse 11 also drives the electrolysis device 12 described below, with which a defined amount of brown gas (HHO) and in particular the energy-enriched gaseous water (HOH) initially contained in the hydrogen-oxygen gas mixture is constantly generated by electrolytic water decomposition during operation of the internal combustion engine and is fed via a gas supply line 13 into the part of the air supply line 4 located between the air mass meter 5 and the turbocharger 6.

This in 2 The electrolysis device 12 shown comprises a closed housing 14 made of plastic with a gas outlet nozzle extending from the housing cover 15, onto which a cover 16 is placed, which is held in a sealed manner by means of an O-ring (not shown in each case). A pipe section 17 extending into the gas outlet nozzle extends from the horizontal inside of the cover 16 to accommodate a filter (not shown) which is intended to retain salt particles entrained by the gas generated during electrolysis, as well as water and water vapor. A gas connection nozzle 27 attached to the cover 16 above the filter is connected to the 1 The cover 16 can be easily removed manually from the gas outlet nozzle formed on the housing cover 15 in order to clean the filter. The opening resistance of the cover 16 is limited to a low operating pressure of 0.1 bar.

In a downwardly offset section 18 of the housing cover 15, i.e. in a plane lowered compared to the housing cover and the gas outlet opening formed in it, there is a filling opening (not shown) that can be closed with a screw cap 19 for the electrolyte that can be introduced into the housing 14 up to the level of the lowered section 18 of the housing cover 15, here preferably a 3.5 to 5.0 percent potassium hydroxide solution. Due to the maximum filling height h thus limited, a certain minimum height of the gas reservoir in the gas collection chamber 24 of the electrolysis device 12 is set and it is also prevented that electrolyte accidentally gets into the gas supply line 13 leading to the intake tract of the engine.

Electrode plates 20, which are 1 mm thick here, are immersed in the electrolyte and are fixed in grooves (not shown) at a distance of approximately 1 mm from one another on the bottom and on two opposite side walls of the housing 14, as well as in the area of the upper edges of the plates. The electrode plates 20 can thus be easily assembled and disassembled for cleaning or replacement. The electrode plates 20 each have one or more holes (not shown) so that the chambers 37 formed between them are connected to one another and can be flowed through by the electrolyte. The two outer electrode plates 20', 20" are each connected to the negative or positive pole of the vehicle battery 9 via a connecting line 21 and connection terminals 22 attached to the housing cover 15. Depending on the battery voltage (e.g. 12 - 15 volts for cars) and the number of electrode plates 20, an optimal voltage of approximately two volts for the electrolysis process is present in the chambers 37 formed between them. The width of the electrode plates 20 is preferably greater than their height, so that the electrode plates 20 - when the electrolyte is gradually being used up - are immersed in the electrolyte to a sufficient height over a long period of time and a sufficient amount of Brown's gas is generated without constantly refilling the electrolyte. One liter of electrolyte is sufficient for approximately 50 operating hours or up to 5000 kilometers for a 3I diesel engine.

How 3 shows, it is also conceivable that a centrally arranged electrode plate 20" is connected to the positive pole of the vehicle battery and the two outer electrode plates 20' are connected to the negative pole in order to ensure a larger electrode surface and thus a high gas generation rate with the central anode and two outer cathodes and the electrode plates arranged between them in a compact design of the electrolysis device.

How 1 shows, a first control unit 23 with an integrated modulator (not shown) is connected to the electrolysis device 12 for converting the direct current supplied by the vehicle battery 9 into - essentially rectangular - current pulses, which cause the system consisting of the electrode plates 20 and the electrolyte located between them to oscillate, so that the hydrogen, oxygen and water gas bubbles (Browns gas) formed during the electrolysis are better detached from the electrode plates 20 by the movement of the entire system and thus a maximum electrode surface is always available for generating a high volume of Browns gas as an additive for the fuel-air mixture in the engine combustion chamber 1. Due to the water molecules set in vibration by the pulsating current, in addition to the electrolysis of water into hydrogen and oxygen, a larger part of the water molecules contained in the electrolyte are also spread out to form linear water isomers (HOH), i.e. the formation of energy-enriched, gaseous water molecules as Component of Brown's gas is stimulated and supported so that only a small amount of additive is required for the combustion process, but with significantly higher energy than conventional oxyhydrogen gas. The pulsating current and the vibrations generated in the electrolysis system can be generated continuously or at intervals of the same or different lengths and at different frequencies and amplitudes (current strengths) in order to be able to influence the volume of gas generated and the structure of the gas during engine operation and in particular to provide the energy-rich Brown's gas. Due to the increased gas production due to the vibration of the electrolysis system, power consumption can be reduced and a high gas yield can still be achieved.

The electrolysis device 12 is provided with a gas collecting chamber 24 arranged above the respective electrolyte level, in 1 The pressure relief valve 25, shown only schematically, is provided as additional safety (opening at an operating pressure in the gas collection chamber - here >0.1 bar).

Within a gas pressure =< 0.1 bar, an immediate transfer of the generated gas and in particular of the only short-term, high-energy gaseous water molecules into the intake tract is guaranteed while they are still being created. Further protection against the occurrence of an impermissibly high pressure in the electrolysis device 12 is provided by the cover 16, which is held on to the housing 14 only by a plug connection and which is stripped off the gas outlet nozzle formed on the housing cover 15 if the gas pressure is too high. The concentration of potassium hydroxide in the aqueous electrolyte solution can be monitored with a density meter 26 extending into the electrolyte, while the fill level in the housing 14 can be determined with a level meter 28 and the temperature of the electrolyte is displayed with a temperature sensor 29. With an operating temperature of 60 to 65 °C and preferably a KOH content of 3.5 to 5.0%, in conjunction with the pulsed current applied to the electrolysis device 12, and at a current strength that is significantly lower than conventional electrolysis devices used in internal combustion engines, a quantity of gas sufficient to act as an additive for the Brown's gas mixture is generated. The required plate area and the electrolyte consumption are comparatively small. The electrolysis device can therefore be small and compact and requires little maintenance. Due to the low power consumption, the electrolysis device can be powered by the vehicle's alternator connected to the vehicle battery. As soon as the fill level or the KOH concentration or the temperature of the electrolyte are outside a predetermined range, this state is indicated by a signal initiated by the first control unit.

According to 1 Downstream of the electrolysis device 12, a water separator 30, a water detector 30a and a gas filter 31 for separating out any water vapor still contained in the Brown's gas and for separating out salt particles are integrated into the gas supply line 13 connected to the air supply line 4. Via a flow meter 32, a burn-back protection device 33 and a throttle valve 34, the gas mixture finally reaches a Venturi nozzle 35 which opens directly into the air supply line 4 downstream of the air mass meter 5 and in front of the turbocharger 6. The main control unit 8 which is connected to the internal combustion engine as well as the throttle valve 7 and the air mass meter 5 is connected via a second control unit 36 to the first control unit 23 assigned to the electrolysis device 12, which in turn is electrically connected to the flow meter 32 and the air mass meter 5 as well as the throttle valve 34.

The burn-back protection 33 comprises a porous structure made of a sintered material that prevents a flame generated by combustion in the engine compartment from flashing back and thereby causing the gas mixture stored in the gas reservoir of the electrolysis device to ignite. The throttle valve 34 connected to the first control unit 23 ensures that when the engine is running at low power, for example when idling, and the gas consumption is correspondingly low due to the low negative pressure in front of the turbocharger 6, an excessive amount of gas does not enter the intake tract. Finally, the task of the Venturi nozzle 35 is to intensively swirl the Browns gas introduced into the air supply line 4 in the air drawn in via the air filter box 3 and to distribute it very finely and evenly.

An important function in the overall system is also played by the flow meter 32, which is integrated into the gas supply line 13 downstream of the water separator 30 and gas filter 31. This meter measures the amount of gas generated in the electrolysis device 12 and transmits the measurement result to the control unit 23 of the electrolysis device 12. The first control unit 23 also receives information from the air mass meter 5 about the amount of air drawn in, depending on the vehicle operation (idling, stop-and-go driving, speed, acceleration, etc.), and from the main control unit 8 and the second control unit 36 about the negative pressure in the intake tract and other engine operating data. Finally, the first control unit 23 is device 23 is also connected to the throttle valve 34 via a control line, so that a quantity of gas adapted to the amount of air to be supplied to the turbocharger or engine combustion chamber based on the respective engine operation is fed into the intake tract and per volume unit of intake air a defined quantity of gas of 0.05 to 0.5 per mille per litre of intake air is always sprayed in the air supply line 4 by means of the Venturi nozzle 35 and reaches the engine combustion chamber 1. Regardless of the respective vehicle and engine operation, the fuel in the engine combustion chamber always contains a certain percentage, the same proportion per volume unit of intake combustion air, of Brown's gas and thus of the high-energy, gaseous water molecules that act as ignition nuclei.

The gas production in the electrolysis device 12 is thus essentially controlled by the engine speed (main control unit), the intake air quantity (air flow meter), the actual gas quantity produced (flow meter) and the gas quantity specified per intake volume unit (throttle valve) using the amplitude and structure of the current pulses generated. Only as much gas is produced as is required for the respective vehicle/engine operation for rapid ignition and complete combustion of the fossil fuel. This means that the percentage of Brown's gas in an intake volume unit is deliberately kept low and does not act as an additional fuel in the conventional way, but rather only has the function of an additive in the small amount. This means that the gaseous water molecules evenly distributed in the combustion chamber act only as starting seeds or ignition seeds, which accelerate and intensify the ignition of the fuel-air mixture present in the engine combustion chamber during the combustion cycle. The released reaction energy ignites the fuel explosively at a number of ignition points and ensures homogeneous and complete combustion of the fuel introduced into the combustion chamber. The fuel is used more efficiently simply because the gaseous water molecules of the Browns gas only act as ignition seeds, so that the engine performance can be improved and fuel consumption and thus pollutant emissions can be reduced. In addition, the exhaust gas temperature and thus the nitrogen oxide and carbon dioxide emissions are further reduced. The equipment and energy required for the continuous provision of Browns gas is low because only a limited amount of gas is produced in a controlled manner.

List of reference symbols

Claims

Method for operating an internal combustion engine with a gas produced by electrolysis of water, which is additionally supplied to the fossil fuel in the engine combustion chamber with the combustion air gas mixture produced by this method, characterized in that the amount of air sucked into the intake tract of the engine is measured according to the respective engine operation and per unit volume of combustion air sucked in at any one time an equal, limited amount of energy-enriched, gaseous water molecule-containing Browns gas, generated with a pulsating current electrolysis device, which only acts as an additive, is fed directly, i.e. without intermediate storage of the combustion air, wherein the percentage of gas molecules present in the fuel during the combustion process is limited in such a way that the energy-enriched, gaseous water molecules evenly distributed in the fuel-air mixture only serve as starting or ignition nuclei that ignite the fuel for an early and long-lasting intensive and complete combustion, wherein the proportion of the Browns gas amount supplied to one liter of intake air is between 0.05 and 0.5 per thousand and wherein: the amount of Browns gas produced in the electrolysis device is determined depending on the respective engine operation on the basis of the amount of Browns gas supplied to the intake tract by a The air quantity detected by the air mass meter is controlled in conjunction with the amount of Browns gas actually produced by the electrolysis device, as detected by a flow meter.

Procedure according to Claim 1 , characterized in that the current pulses acting on the electrolysis device are rectangular or trapezoidal in shape.

Procedure according to Claim 1 or 2 , characterized in that the current pulses for influencing the gas yield and the amount of energy-enriched, gaseous water molecules are generated continuously or at intervals and with different amplitudes.

Method according to one of the Claims 1 until 3 , characterized in that the current pulses have a variable flank rise angle for influencing the gas yield and the amount of energy-enriched, gaseous water molecules in the Browns gas.

Method according to one of the Claims 1 until 4 , characterized in that , in order to increase the Browns gas yield, the current pulses are controlled as a function of the electrolyte temperature and concentration as well as the electrode plate geometry and the plate spacing so that the system consisting of electrode plates and electrolyte is operated in resonance for rapid detachment from the electrode plates and their flushing.

Arrangement for carrying out the method according to one of the preceding claims, with an air supply line (4) which is connected from an air filter box (3) to the engine combustion chamber (1) of the internal combustion engine for supplying an air quantity adapted to the respective engine operation, into which a gas supply line (13) connected to an electrolysis device (12) supplied by a vehicle battery (9) opens, characterized in that an air mass meter (5) for detecting the volume of air sucked in depending on the respective engine operation is integrated in the air supply line (4) before the mouth of the gas supply line (13) and a flow meter (32) for detecting the amount of gas actually produced and a throttle valve (34) for finally setting the gas volume adapted to the amount of air delivered are integrated in the gas supply line (13) in the flow direction, each of which is connected to a first control device (23) assigned to the electrolysis device (12) for regulating the gas production on the basis of the amount of air sucked in and the amount of gas detected with the aid of a control signal which is continuously controlled by a modulator. or at intervals of transformed pulsating current variable in frequency, amplitude, flank angle and duration.

Arrangement according to Claim 6 , characterized in that a water separator (30), a water detector (30a) and a gas filter (31) for gas purification and a burn-back protection device (33) consisting of a gas-permeable ceramic material for preventing a flashback in the electrolysis device (12) are integrated into the gas supply line (13).

Arrangement according to Claim 6 , characterized in that the first control unit (23) is connected via a second control unit (36) to a main control unit (8) assigned to the internal combustion engine.

Arrangement according to Claim 6 , characterized in that the gas supply line (13) opens into the air supply line (4) via a Venturi nozzle (35) arranged downstream of the air mass meter (5) for swirling and uniformly distributing the molecules contained in the gas flow in the intake air.

Arrangement according to Claim 6 , characterized in that the electrolysis device (12) has a plurality of electrode plates (20, 20', 20") provided with openings and arranged parallel at a distance in a housing (14) filled with an electrolyte, and the two outer electrode plates (20', 20") or a central electrode plate (20") and the two outer electrode plates (20) are connected to the plus or minus voltage via the first control device (23). Negative pole of the vehicle battery (9), wherein a gas collection chamber (24) delimited above the electrode plates (20, 20', 20") by a housing cover (15) can be connected to the gas supply line (13) via a cover (16) which can be plugged onto a gas outlet nozzle in a sealing manner and which opens automatically when a certain excess pressure in the gas collection chamber (24) occurs, with an internal pipe section (17) accommodating a filter and a gas connection nozzle (27).

Arrangement according to Claim 10 , characterized in that the housing cover (15) has a section (18) lowered to the maximum electrolyte filling level in the housing (14) with a filling opening which can be closed by a screw cap (19).

Arrangement according to Claim 10 , characterized in that the electrode plates (20) are fixed in grooves provided on the bottom and two opposite side walls of the housing (14) and in the region of the upper edge of the plate.

Arrangement according to Claim 10 , characterized in that the electrolysis device (12) has a density meter (26), a level meter (28) and a temperature sensor (29) as well as a pressure relief valve (25) for monitoring the electrolyte.

Arrangement according to Claim 10 , characterized in that the electrode plates (20) have a width that is significantly greater than their height, and as a result a sufficiently large electrode surface is covered with electrolyte over a long period of time.

Arrangement according to Claim 10 , characterized in that the electrode plate thickness is approximately one millimeter and the electrode plate spacing is between 1.5 and 10.5 millimeters.

Arrangement according to Claim 10 , characterized in that the electrolyte in the electrolysis device (12) is a 3.5 to 5.0 percent potassium hydroxide solution.

Arrangement according to Claim 16 , characterized in that the electrolyte has an increased concentration to lower the freezing point in winter operation and/or contains up to a maximum of 10% ethylene glycol as an antifreeze.