Fuel supply system for a combustion engine, system components and methods

Abstract

The invention relates to generating fuel for an internal combustion engine such as a piston engine or a gas turbine. The invention relates to a system, apparatuses and methods for producing hydrogen and for hydrogen fuel enhancement. The invention relates in particular to an electrolyser that comprises an electrolyser housing enclosing an interior space that is adapted for containing a water reservoir. The electrolyser housing comprises a side wall and a top cover and a bottom cover that are tightly connected to the side wall. The electrolyser further comprises a plurality of elongate electrodes that extend from the bottom cover and / or the top cover into the interior space enclosed by the electrolyser housing. The electrodes are electrically isolated from the electrolyser housing and are electrically connected to electric conductors for feeding DC current to the electrodes. The electric connections are configured to connect electrodes acting as cathodes to a negative voltage terminal of a DC electric power source and to connect electrodes acting as anodes to a positive voltage terminal of a DC electric power source.. The invention further relates to a method of producing hydrogen enhanced hydrocarbon fuel comprising the steps of. - producing hydrogen from water by means of an electrolyser - vaporizing hydrocarbon fuel - mixing the hydrogen and the vaporized hydrocarbon fuel - compressing the mixture of hydrogen and the vaporized hydrocarbon fuel, and - ionizing the compressed mixture of hydrogen and the vaporized hydrocarbon fuel.

Description

[0001] The invention relates to generating fuel for an internal combustion engine such as a piston engine or a gas turbine. The invention relates to a system, apparatuses and methods for producing hydrogen and for hydrogen fuel enhancement.

[0002] The invention relates in particular to an electrolyser for generating hydrogen on demand.

[0003] For hydrogen fuel enhancement a conventional hydrocarbon fuel such as gasoline is mixed with hydrogen. For driving a combustion engine, the mixture is combusted in a combustion chamber of the internal combustion engine.

[0004] Hydrogen (H 2 ) can be produced by means of electrolysis. Various types of electrolysis are known. An electrolyser typically comprises a water reservoir and at least one anode and one cathode contacting the water in the water reservoir. A DC current between the cathode and the anode causes electrolysis wherein the DC voltage applied to the cathode and the anode causes cations (H +< ) to move to the cathode while anions (OH) are moving to the anode. At the anode, water molecules lose electrons and are oxidized to form oxygen gas and positively charged hydrogen ions, i.e. cations (H +< ). Cations are neutralized (H +< plus electron -> H) at the cathode and can exit the water reservoir as gaseous hydrogen Hz. An electrolyser thus produces hydrogen (Hz).

[0005] While there are many uses for hydrogen, however, the production rate of hydrogen is typically very low. If a high volume of hydrogen is needed, hydrogen is stored in a tank.

[0006] For automotive and aerospace applications, hydrogen is attractive because it is cheap to produce and the product from the combustion of hydrogen is water vapour (H 2 O). If hydrogen is mixed with oxygen and ignited, H 2 O is generated which is very environmental friendly. The mixture or hydrogen and oxygen is highly explosive and produces 10-times more energy than the same amount of any other liquid or gas fuel. Therefore, in many industries there is an interest in using hydrogen to power combustion engines. However, due to the low production volume, hydrogen is typically stored in a small gas tank and the engine is powered with hydrogen from the gas tank.

[0007] According to another concept, hydrogen can be mixed with conventional hydro-carbon fuel for improving the combustion and saving fuel.

[0008] It is an object of the invention to provide means for producing an enhanced fuel for a combustion engine on demand.

[0009] According to a first aspect, an electrolyser is provided that comprises an electrolyser housing enclosing an interior space that is adapted for containing a water reservoir. The electrolyser housing comprises a side wall and a top cover and a bottom cover that are tightly connected to the side wall. The electrolyser further comprises a plurality of elongate electrodes that extend from the bottom cover and / or the top cover into the interior space enclosed by the electrolyser housing. The electrodes are electrically isolated from the electrolyser housing and are electrically connected to electric conductors for feeding DC current to the electrodes. The electric connections are configured to connect electrodes acting as cathodes to a negative voltage terminal of a DC electric power source and to connect electrodes acting as anodes to a positive voltage terminal of a DC electric power source.

[0010] In a preferred embodiment, the electrodes extend in parallel to a central axis of the side wall of the electrolyser housing.

[0011] In a further preferred embodiment, the electrodes extend from the bottom cover into the interior space enclosed by the electrolyser housing.

[0012] Preferably, at least some of the electrodes are tube-shaped.

[0013] In some embodiments, the cathodes are tube shaped so as to enclose a lumen and the anodes are co-axially arranged with the cathodes wherein each anode is arranged within the lumen of a respective cathode.

[0014] Preferably, the electrodes are arranged along at least one circle around a central axis of the side wall of the electrolyser housing. The electrodes preferably are equally spaced along the at least one circle.

[0015] The electrolyser preferably further comprises an ultrasound generator that is configured and arranged for emitting ultra sound into the interior space enclosed by the electrolyser housing. Preferably, the ultrasound generator is mechanically connected to a cone extending into the interior space enclosed by the electrolyser housing.

[0016] According to another aspect that may be combined with the first aspect, a hydrogen fuel enhancer comprising a mixing stage and an ionizing stage that is at least indirectly fluid-connected to the mixing stage is provided. The mixing stage comprises a hydrogen inlet and a hydrocarbon fuel inlet and is configured for mixing hydrogen with hydrocarbon fuel. The hydrocarbon fuel preferably is vaporized. Vaporisation of the hydrocarbon fuel preferably is improved by exposing the hydrocarbon fuel to ultrasound prior to feeding the hydro-carbon fuel to the mixing chamber. This improves mixing of hydrogen and vaporized hydrocarbon fuel.

[0017] The hydrogen fuel enhancer preferably further comprises a compressor stage that is arranged between the mixing stage and the ionizing stage and that is configured to compress a gas mixture supplied by the mixing stage and for feeding the compressed gas mixture to the ionizing stage.

[0018] The hydrogen fuel enhancer preferably further comprises a compressor diffuser for reducing the velocity and increasing the static pressure of the compressed gas mixture.

[0019] The ionizing stage of the hydrogen fuel enhancer preferably comprises an inner ionizer electrode having a cylindrical outer wall portion and an outer, tube-shape ionizing electrode that is radially spaced from the cylindrical outer wall portion of the inner ionizer electrode. The inner ionizer electrode and the outer ionizing electrode thus define an annular gas passageway between the inner ionizer electrode and the outer ionizing electrode. During operation, the compressed mixture of vaporized fuel and hydrogen passes through the passageway between inner ionizer electrode and the outer ionizing electrode and the molecules in the gaseous mixture are at least in part ionized. Ionization causes the electrically charged molecules to work together as one. During operation, the inner ionizer electrode and the outer ionizing electrode are connected to a high voltage source for generating an electric field between the inner ionizer electrode and the outer ionizing electrode leading to ionization of molecules passing through the gas passageway between the inner ionizer electrode and the outer ionizing electrode.

[0020] According to a further aspect, a system comprising at least one hydrocarbon fuel vaporizer, at least one electrolyser, at least one hydrogen fuel enhancer and at least one combustion engine is provided. The hydrocarbon fuel vaporizer and the electrolyser are fluid-connected to the hydrogen fuel enhancer for supplying the hydrogen fuel enhancer with both, vaporized hydrocarbon fuel and hydrogen. The hydrogen fuel enhancer is fluid-connected to the combustion engine for supplying the combustion engine with hydrogen enhanced fuel.

[0021] According to a further aspect, a method of producing hydrogen enhanced hydrocarbon fuel is proposed. The method comprises the steps of. continuously producing hydrogen from water by means of an electrolyser continuously vaporizing hydrocarbon fuel mixing the hydrogen and the vaporized hydrocarbon fuel compressing the mixture of hydrogen and the vaporized hydrocarbon fuel, and ionizing the compressed mixture of hydrogen and the vaporized hydrocarbon fuel.

[0022] This system and the method provide hydrogen enhanced fuel that saves between 50 % and 70 % of hydrocarbon fuel due to the use of the hydrogen in the mixture. The hydrogen enhanced fuel is be almost 50% cleaner than normal hydrocarbon fuel. As a result, using the system and the method of the invention, the harmful gases are reduced to 15% in total in comparison with the same engine using normal hydrocarbon fuel systems.

[0023] With the system and the method of the invention, the liquid fuel consumption is taken to a minimum. While vaporized hydrocarbon fuel has a low ignition power when mixed with a relative low portion of hydrogen a normal ignition power volume in the combustion chamber is achieved taking advantage of the cooling properties of the liquid fuel vapour that allows the engine to handle the high ignition temperature of the hydrogen.

[0024] The invention shall now be described by way of an example with reference to the figures. Of the figures, Fig. 1:is s schematic block diagram of a fuel supply system according to the invention; Fig. 2a and b:are perspective views of a first embodiment of an electrolyser; Fig. 3a:shows a longitudinal cross-section of the electrolyser of figure 2; Fig. 3b:is a side view of the electrolyser of figure 2; Fig. 3c:is a top view of the electrolyser of figure 2; Fig. 3d:is a bottom view of the electrolyser of figure 2; Fig. 3e:illustrates an electrode arrangement of the electrolyser of figures 3a to 3d; Fig. 3f:illustrates an alternative arrangement of electrodes for an electrolyser similar to the electrolyser of figures 3a to 3d, Fig. 4:is an exploded perspective view of the electrolyser of figures 2 and 3; Fig. 5a and b:illustrate perspective views of an alternative embodiment of an electrolyser; Fig. 6a:shows a longitudinal cross-section of the alternative electrolyser according to figure 5; Fig. 6b:is a side view of the alternative electrolyser of figure 5; Fig. 6c:is a top view of the alternative electrolyser of figure 5; Fig. 6d:is a bottom view of the alternative electrolyser of figure 5; Fig. 7a:is an exploded perspective view of the alternative electrolysers of figures 5 and 6; Fig. 7b:illustrates the electrode arrangement in the alternative electrolyser; Fig. 8:is a side view of a carbon fuel enhancer; Fig. 9a and 9b:are perspective views of the carbon fuel enhancer of figure 8; Fig. 10:illustrates a longitudinal cross-section of the carbon fuel enhancer of figures 8 and 9; Fig. 11:is an exploded perspective view of the carbon fuel enhancer of figures 8 to 10 illustrating the components of the carbon fuel enhancer; Figs. 12a - e:are different views of a hydrocarbon fuel vaporizer; and Fig. 12f:is a perspective side view of an ultrasound emitter plate of the hydrocarbon fuel vaporizer.

[0025] A fuel supply system for a combustion engine according to a preferred embodiment comprises an electrolyser 100, a hydrogen fuel enhancer 200 and a hydrocarbon fuel vaporizer 300. The electrolyser 100 produces gaseous hydrogen from water, the hydrocarbon fuel vaporizer 300 vaporizes hydrocarbon fuel, for instance gasoline, and the hydrogen fuel enhancer 200 produces a mixture of vaporized hydrocarbon fuel and gaseous hydrogen, ionizes the mixture and feeds the ionized mixture to a combustion engine 400, for instance a gas turbine or a piston engine.

[0026] The vaporizer 300 comprises an electronic circuit and an ultrasonic emitter for generating ultrasound with a frequency between 110 kHz and 220 kHz. The vaporizer 300 can vaporize almost any liquid hydrocarbon fuel. Due to the low rate of vaporization hydrocarbon fuel will not produce high volume of vapour.

[0027] This vaporized hydrocarbon fuel will not be enough for feeding a gas turbine and keeping it running but it ensures a low ignition temperature comparable to other liquid hydrocarbon fuel.

[0028] Hydrogen fuel alone would be a very good fuel for gas turbines in terms of power delivered per cubic centimetre. Further, the emissions are zero. But there are two problems: the volume of hydrogen needed to run a turbine is relatively high so it is almost impossible to produce enough hydrogen just in time and the Ignition temperature of hydrogen is very high so most of the parts of the hot section of a gas turbine must be redesigned.

[0029] These problems are mitigated by the invention.

[0030] The system illustrated in figure 1 can continuously produce hydrogen enhanced fuel by: continuously producing hydrogen from water by means of an electrolyser continuously vaporizing hydrocarbon fuel mixing the hydrogen and the vaporized hydrocarbon fuel compressing the mixture of hydrogen and the vaporized hydrocarbon fuel, and ionizing the compressed mixture of hydrogen and the vaporized hydrocarbon fuel.

[0031] The hydrogen enhances the ignition power of the fuel and the hydrocarbon fuel in the mixture mitigates the high ignition temperature of the hydrogen.

[0032] The electrolyser 100

[0033] The electrolyser 100 produces gaseous hydrogen from water by way of electrolysis. The electrolyser 100 comprises a housing that encloses a water reservoir and electrodes extending into the water reservoir. The electrodes are anodes 122 and cathodes 124 that during operation are connected to respective terminals of a DC electric power source.

[0034] The electrolyser is a device that uses electricity to split water (H 2 O) into its constituent elements, hydrogen (H 2 ) and oxygen (Oz), through a process called electrolysis.

[0035] The electrolyser contains an electrolyte solution, typically either pure water or a mixture of water and a substance that enhances its conductivity, such as potassium hydroxide (KOH) or sulphuric acid (H 2 SO 4 ). For instance, 3% of NaCl may be added to the water.

[0036] There are two kinds of electrodes immersed in the electrolyte solution: positively charged electrodes, the anodes 122 and negatively charged electrodes, the cathodes 124. These electrodes are usually made of metals like platinum, graphite, or titanium coated with precious metals. In the preferred embodiment, the electrodes 122 and 124 are made of stainless steel because stainless steel does not add any other substance potentially contaminating the hydrogen production to the water in the reservoir.

[0037] When an electric current is passed through the electrolyte solution - for instance water - via the electrodes and an external power source, such as a battery or an electrical outlet, the water molecules near the electrodes undergo a chemical reaction. At each anode 122, water molecules lose electrons and are oxidized to form oxygen gas and positively charged hydrogen ions (H+). The half-reaction at the anode is:         2H 2 O(l) → Oz(g) + 4H +< (aq) + 4e -< wherein - according to the standard usage of these indicators - "I" means liquid, "g" means gaseous and "aq" means dissolved in water, (aqueous solution). At each cathode 124, hydrogen ions (H +< ) gain electrons (e -< ) and are reduced to form hydrogen gas. The half-reaction at the cathode is:         4H +< (aq) + 4e -< → 2H 2 (g)

[0038] The generated hydrogen and oxygen gases are then collected commonly or separately.

[0039] The hydrogen gas produced by electrolysis can be used as a clean and renewable fuel for various applications, including fuel cells to generate electricity, transportation (such as powering hydrogen fuel cell vehicles), industrial processes (such as chemical synthesis), and energy storage. An application that is of interest for the invention is using hydrogen for fuelling combustion engines and in particular for producing hydrogen enhanced hydrocarbon fuel.

[0040] The electrolyser 100 comprises a housing 112 including an interior space 120 that can be filled with water for providing a water reservoir. Electrodes, i.e. cathodes 124 and anodes 122 are extending from the bottom of the housing 112 into the interior space 120. A plurality of cathodes 124 and a plurality of anodes 122 are provided. According to a preferred embodiment, the housing 112 of the electrolyser 100 comprises as side wall 114 with a circular cross-section. The side wall 114 thus defines a cylindrical interior space 120. The side wall 114 has two longitudinal ends. The interior space 120 enclosed by the housing 112 is closed by the side wall 114 and two covers, i.e. a top cover 118 and a bottom cover 116, connected to the longitudinal ends of the side wall 114 in fluid tight manner.

[0041] During operation, a central axis 126 defined by the side wall 114 is extending in a vertical direction. Therefore, one of the covers is a bottom cover 116 and the other cover is a top cover 118.

[0042] According to the preferred embodiment, the anodes 122 and the cathodes 124 are mechanically connected to the bottom cover 116 and extend in a direction that essentially is parallel to the central axis 126 defined by the side wall 114.

[0043] According to a particularly preferred embodiment, an ultrasound generator 140 is arranged in the bottom cover 116 so as to emit ultrasound to the water reservoir enclosed in the interior space 120 of the electrolyser 100. Preferably, the ultrasound emitter is arranged centrally in the bottom cover 116. According to a further preferred embodiment, the ultrasound generator 140 comprises a sound emitting structure that preferably comprises a cone 142 extending into the water reservoir enclosed by the electrolyser 100. The cone 142 of the ultrasound generator 140 preferably is arranged coaxially within the cylindrical side wall 114 of the electrolyser 100. Ultrasound with a specific frequency makes the cathodes 124 and anodes 122 vibrate with the same harmonic frequency of the hydrogen molecules in the bubbles that emerge at the cathode, thus making the separation of the hydrogen bubbles from the cathode faster than without the ultrasound. Thus a higher minute volume of hydrogen can be produced.

[0044] Both, anodes 122 and cathodes 124, preferably have an elongate shape and extend in parallel to the central axis 126 defined by the side wall 114. In particular, the anodes 122 and the cathodes 124 can be implemented as rods or tubes that are arranged in an equidistant manner along a circle 125 around the ultrasound generator 140 and the ultrasound generator's cone 142 in particular.

[0045] In one embodiment, each anode 122 is enclosed by a respective cathode 124 wherein the anode 122 and the cathode 124 are spaced by a radial interspace of at least 1.5 mm. In such embodiment, the cathodes 124 are tubes while each respective anode 122 may be a rod or a tube. However, hollow, tube-like anodes 122 are preferred. According to this embodiment, anodes 122 and cathodes 124 are arranged in pairs. Preferably, between at least 6 and at most 36 anode-cathode-pairs are provided. For instance, the number of anode-cathode-pairs can be between 8 and 16, for instance 12. The anode-cathode-pairs are equidistantly arranged on a circle around the central ultrasound generator 140 wherein the cathode tubes of the anode-cathode-pairs are radially spaced from the side wall 114.

[0046] In the embodiment, wherein an anode 122 is enclosed by a cathode tube, the anode 122 and the cathode 124 of one anode-cathode-pair are preferably arranged concentrically.

[0047] In an alternative embodiment, anodes 122 and cathodes 124 are arranged side by side. For instance, the cathodes 124 might be equally spaced along a first circle around the central axis 126 of the side wall 114 and the anodes 122 may be equidistantly arranged along a second circle around the central axis 126 of the side wall 114, the second circle having a larger diameter than the first circle. In such embodiment, the number of anodes 122 arranged along the second circle is preferably larger than the number of cathodes 124 arranged along the first circle.

[0048] Depending on the overall dimensions, the cathodes 124 may extend through the conical wall of the ultrasound generator's cone 142.

[0049] According to a further preferred embodiment, a separating wall 132 is provided that extends concentrically with respect to the side wall 114 and has a smaller, circular cross-section than the side wall 114. The separating wall 132 divides the reservoir enclosed by the side wall 114 into an inner reservoir enclosed by the separating wall 132 and an annular outer reservoir extending radially between the separating wall 132 and the side wall 114. Openings 134 in the separating wall 132 are providing a fluid connection between the inner reservoir and the outer reservoir. The openings 134 preferably are arranged closer to the bottom cover 116 than the top cover 118. The separating wall 132 preferably extends between the bottom cover 116 and the top cover 118 and is connected to both, the bottom cover 16 and the top cover 118 in order to cause two separate headspaces, one headspace for collecting gaseous oxygen (Oz) and one headspace for collecting gaseous hydrogen (H 2 ). For supplying electric current to the cathodes 124 and the anodes 122, a cathode connector 124.1 and an anode connector 122.1 are provided. An electric circuit 144 for supplying electric current to the cathodes 124 and the anodes 122 during operation of the electrolyser 100 is connected to the cathode connector 124.1 and the anode connector 122.1, respectively, as schematically indicated in figure 2b.

[0050] The rod or tube shaped electrodes - i.e. anodes 122 and cathodes 124 - are extending from the bottom cover 16 upwards into the water reservoir enclosed by the side wall 114. The rod or tube shaped electrodes are shorter than the side wall 114 and do not contact the top cover 118. During operation the interior space 120 of the electrolyser 100 is not completely filled with water. Rather, a headspace 120.1 within the electrolyser 100 is filled with gas. During operation of the electrolyser 100, the gas will be hydrogen and / or oxygen produced by the electrolyser 100.

[0051] The rod or tube shaped electrodes 122 and 124 are dimensioned to be fully immersed in water, i.e. they do not extend into the gas-filled headspace 120.1.

[0052] In the embodiment having a separating wall 132, the inner gas-filled headspace 120.1.2 within the separating wall 132 will be filled with hydrogen while the outer gas-filled headspace 120.1.1 between the separating wall 132 and the side wall 114 will be filled with oxygen. Accordingly, the separating wall 132 is connected to the top cover 118 to thus separate the two gas-filled headspaces from one another. In the top cover 118, a hydrogen outlet 128 is provided that is fluidly connected to the inner headspace 120.1.2 and an oxygen outlet 130 that is fluidly connected to the outer headspace 120.1.1.

[0053] The rod or tube shaped cathodes 124 are arranged within the inner reservoir enclosed by the separating wall 132 while the anodes 122 are arranged between the separating wall 132 and the side wall 114. Thus, hydrogen that is produced by the cathodes 124 will be collected in the inner headspace 120.1.2 while oxygen produced by the anodes 122 is collected in the outer headspace 120.1.1. In this embodiment, a hydrogen outlet 128 and an oxygen outlet 130 are provided as separate outlets arranged at the top cover 118 of the electrolyser 100.

[0054] The separating wall 132 preferably is made from an isolating material, for instance from plastic.

[0055] For refilling the water reservoir in the electrolyser 100, a water inlet 136 is provided in the side wall 114 close to the bottom cover 116.

[0056] The ultrasound generator 140 and the cone 142 connected thereto improve the efficiency of the electrolyser. The cone 142 is connected to the ultrasound generator 140 and guides the ultrasound into the interior, water-filled space of the electrolyser 100. The ultrasound generator 140 generates an ultrasound with a frequency preferably between 4 and 10 MHz.

[0057] The ultrasound has the effect of causing the cathodes 124 and anodes 122 to vibrate with the harmonic frequency of the hydrogen molecules in the bubbles that emerge at the cathode, thus making the separation of the hydrogen bubbles from the cathode faster than without the ultrasound. Thus a higher minute volume of hydrogen can be produced.

[0058] The cathodes 124 and the anodes 122 are electrically connected to an electric power source providing a DC voltage between 12 V and 24 V via electric connectors 138. Electric feed-throughs through the bottom cover 16 connect each electrode with a respective terminal of the DC voltage electric power source. To commonly connect all anodes 122 to one terminal of the electric power source, an anode connector, for instance a ring-shaped anode connector 138.1 may be provided. Likewise, for commonly connecting all cathodes 124 to another terminal of the electric power source, a cathode connector, for instance a ring-shaped cathode connector 138.2 may be provided.

[0059] Further, the electric circuit 144 is configured for producing voltage pulses with a frequency between 100 Hz and 200 kHz. The electric circuit 144 is connected to the cathodes 124. In a preferred embodiment the electric circuit is tuned to produce voltage pulses with a frequency of 330 Hz (i.e. 330 pulses per second) that produce harmonic waves within the hydrogen. In an electrolysis system, the hydrogen emerges at the cathodes 124 but part of the gaseous hydrogen bubbles tend to stick to the respective cathode, making the system inefficient. By applying electric pulses to the cathode with a frequency corresponding to a harmonic frequency of the hydrogen bubbles and / or of the cathodes 124, the separation of the hydrogen from the cathodes is stimulated and all the produced bubbles are released at the same time. The harmonic frequencies of the cathode depend on the material characteristics and the shape of the cathodes 124. If the frequency of the voltage pulses corresponds to the resonance frequency of a molecule, for instance HzO, is possible to improve splitting of the molecule.

[0060] Further, a plurality of ultraviolet light emitting light sources, for instance diodes (UV-LEDs) are provided. The UV-LEDs illuminate the water reservoir close to the cathodes 124. The UV light sources preferably are distributed around the cathodes for exhibiting the hydrogen bubbles to UV light once the hydrogen bubbles appear at the cathode surface. The LEDs further sterilize and germinate the water in order to prevent contamination. The UV-LEDs are not shown on the drawings.The hydrogen fuel enhancer 200

[0061] The hydrogen produced by the electrolyser 100 is directly fed to a hydrogen fuel enhancer 200.

[0062] The hydrogen fuel enhancer 200 comprises three consecutive stages, a mixing stage 210, an optional compressor stage 212 and an ionizing stage 214. Hydrogen and vaporized fuel is fed to a mixing chamber 220 of the mixing stage wherein the hydrogen and the vaporized fuel are mixed. The mixture comprising hydrogen and vaporized fuel then is compressed in the compressor stage 212 and fed to the ionizing stage 214 wherein the gas mixture is ionized. The ionized gas mixture then is fed to a combustion engine, for instance a gas turbine.

[0063] The mixing chamber 220 has two inlets 222 and 224. One inlet is a hydrogen inlet 224 for feeding hydrogen into the mixing chamber 220 of the hydrogen fuel enhancer 200 while the other input is a vaporized fuel inlet 222 for feeding vaporized fuel into the mixing chamber220 of the hydrogen fuel enhancer 200. The mixing chamber 220 has a cylindrical outer wall 226 and an inner wall 228. The mixing chamber 220 is annularly arranged between the inner wall 228 and the outer wall 226. The mixing chamber's inner wall 228 has a dual cone shape, i.e. initially has a diameter the increases in a downstream direction and finally decreases further downstream. Accordingly, the mixing chamber's inner wall 228 initially has an increasing diameter in a direction from the inlets 222 an 224 to the compressor stage 212 and then decreases in diameter towards the compressor stage 212. Therefore, the annular shaped mixing chamber 220 initially narrows and then widens again. The mixing chamber 220 for mixing vaporized fuel and hydrogen is preferably arranged around a shaft 236 for driving the compressor of the compressor stage 212.

[0064] The mixing chamber 220 is at least indirectly fluid connected to the ionizing stage 214 with an ionizer housing 240. Preferably, the compressor stage 212 is arranged between the mixing stage 210 and the ionizing stage 214.

[0065] The compressor stage 212 of the preferred embodiment comprises a compressor housing 230 enclosing a compressor wheel 232. The compressor with the compressor housing 230 and the compressor wheel 232 is provided between the mixing chamber and the ionizer 214 for compressing the mixture of hydrogen and vaporized fuel and feeding the compressed mixture into an ionizer chamber 240.4 enclosed by the ionizer housing 240 of the ionizing stage 214. The compressor stage 212 comprises a compressor diffuser for reducing the velocity of the compressed mixture of hydrogen and vaporized fuel and increasing the static pressure of mixture of hydrogen and vaporized fuel when entering the ionizer chamber 240.4. The compressor preferably is driven by an electric motor 238, for instance a brushless electric motor. The compressor can be a centrifugal compressor or a screw compressor that is driven by the electric motor 238. The electric motor 238 preferably has a rotation axis that is arranged in line with a central axis of the mixing chamber 220, the compressor stage 212 and the ionizing stage 214. The electric motor 238 is preferably arranged close to the inlets 222 and 224 of the mixing chamber 220, i.e. in line with and outside of the mixing stage 210, the compressor stage 212 and the ionizing stage 214.

[0066] The ionizing stage 214 comprises the ionizer housing 240. The ionizer housing 240 has a cylindrical housing portion 240.1 and a dome shaped front portion 240.2. An inner surface of the ionizer housing 240 is covered with an insulating housing liner 240.3. The ionizer housing 240 encloses the ionizer chamber 240.4. The ionizer housing 240 encloses the ionizer chamber 240.4 extends from the compressor diffuser 234 to an ionized mixed fuel outlet 250. Sections of the ionizer chamber 240.4 include a gas passageway 246 and a buffer space 248 as described in further detail later herein.

[0067] Attached to the insulating housing liner 240.3 is an outer, tube-shape ionizing electrode 242. The outer ionizing electrode 242 comprises a reduced diameter upstream portion 242.1 that is radially spaced from insulating housing liner 240.3 and full diameter downstream portion 242.2 that abuts the insulating housing liner 240.3.

[0068] Along the reduced diameter upstream portion 242.1 of the outer ionizing electrode 242 an inner ionizing electrode 244 is provided. The inner ionizing electrode 244 comprises an inner ionizing electrode body 244.1 with a cylindrical wall portion 244.2 and dome-shaped front portion 244.3.

[0069] The reduced diameter upstream portion 242.1 of the outer ionizing electrode 242 and the cylindrical wall portion 244.2 of the inner ionizing electrode 244 are radially opposed to and spaced from each other to thus define the gas passageway 246 for the compressed gas mixture therebetween.

[0070] Downstream of the ionizing electrode body's 244.1 dome-shaped front portion 244.3 the buffer space 248 is provided within the ionizer housing 240. The full diameter downstream portion 242.2 of outer ionizing electrode 242 at least partially encloses the buffer space 248. At the downstream end of the buffer space, a fuel outlet 250 is arranged in the middle of the dome shaped ionizer housing front wall 240.2.

[0071] The ionized gas mixture is fed through the gas passageway 246 between the outer ionizing electrode 242 and the inner ionizing electrode 244 to a buffer space enclosed by the ionizer housing 240. During operation, the outer ionizing electrode 242 and the inner ionizing electrode 244 are connected to a high voltage source for generating a strong electric field between the outer ionizing electrode 242 and the inner ionizing electrode 244 for ionizing molecules passing through the passageway 246. The isolating material of the insulating ionizer housing liner prevents sparks and thus inhibits an unintended combustion within the inner ionizing electrode 244. The tube shaped outer ionizer electrode 242 preferably is attached to the insulating inner liner 240.3 of the ionizer housing 240. The tube shaped outer ionizer electrode 242 extends beyond the inner ionizer body 244.1 and thus surrounds the buffer space 248. The ionizer housing 240 has a longitudinal shape extending from the compressor to the dome shaped front wall 240.2 of the ionizer housing 240. In the centre of the dome shaped end wall of the buffer space, a fuel outlet 250 is arranged.

[0072] The inner ionizer electrode 244 comprises a cylindrical outer wall portion 244.2 and a dome shaped front wall portion 244.3 wherein the cylindrical outer wall portion 244.2 and the dome shaped front wall portion 244.3 are made from an electrically conducting material, for instance metal. The dome shaped front wall portion 244.3 of the inner ionizer electrode 244 extends into the buffer space 248 enclosed by the ionizer housing 240.

[0073] The mixture of hydrogen and vaporized fuel that the compressor feeds into the ionizer chamber 240.4 enclosed by the ionizer housing 240 is first guided to the annular passageway 246 between the inner ionizer electrode 244 and the outer, tube-shaped ionizer electrode 242. The outer, tube-shaped ionizer electrode 242 has a reduced inner diameter along the passageway 246 and along the circular wall portion 244.2 of the inner ionizer electrode 244. At the end of the passageway 246, the inner diameter of the outer, tube-shaped ionizer electrode 242 increases while the outer diameter of the inner ionizer electrode 244 decreases due to the dome-shaped front wall portion 244.3 of the inner ionizer electrode 244. As mentioned before, the outer tube-shaped ionizer electrode 242 extends beyond the inner ionizer electrode 244 in a longitudinal direction of the ionizer housing 240.

[0074] The voltage between the opposing annular walls enclosing the passage way of the ionizer preferably is between 5 kV and 12 kV.

[0075] For vaporizing hydrocarbon fuel to be fed into the mixing chamber via the vaporized fuel inlet, the fuel vaporizer 300 is provided that comprises an ultrasonic emitter that produces ultrasound with a frequency between 100 kHz and 220 kHz. Thus, liquid fuel can be vaporized by means of ultrasound. However, the volume produced by the fuel vaporizer would not be enough to drive a gas turbine. Therefore, the vaporized hydrocarbon fuel is mixed with hydrogen.

[0076] The flow rate of hydrogen produced by the electrolyser 100 and the flow rate of vaporized hydrocarbon fuel produced by the vaporizer 300 is high enough to supply a gas turbine 400 on demand. Due to the ionizing of the gas mixture in the hydrogen fuel enhancer 200, the combustion properties of the gas mixture are further improved because due to the electric charge the molecules are forced to work together as one.

[0077] The compressor stage 212 comprises a compressor housing 230 with a compressor wheel 232 arranged therein. At the exit of the compressor stage 212, a compressor diffusor 234 is arranged. Therefore, the gas mixture compressed by the compressor stage 212 is fed into the ionizer chamber 240.4 enclosed by the ionizer housing 240 through the compressor diffusor 234.The hydrocarbon fuel vaporizer 300

[0078] The ultrasound hydrocarbon fuel vaporizer 300 comprises a hydrocarbon fuel reservoir 302 for the liquid hydrocarbon fuel. Figure 12 a is a top view of an embodiment of the vaporizer without top cover, figure 12 b is a side view, figure 12 c is a bottom view and figure 12 d is a cross-sectional view of the vaporizer 300. Figure 12 e illustrates the embodiment of the vaporizer 300 in a semi-transparent perspective view. The hydrocarbon fuel reservoir 302 is enclosed by hydrocarbon fuel reservoir side wall 304 and has a hydrocarbon fuel reservoir outlet 306 that during operation typically is arranged to form the bottom of the hydro-carbon fuel reservoir 302. The hydrocarbon fuel reservoir outlet 306 is sealed by an ultrasound emitter plate 308 (see figure 12 f) that has microscopic holes 310 that prevent the liquid hydrocarbon fuel from leaving the hydrocarbon fuel reservoir 302 because the liquid hydrocarbon fuel cannot pass the holes 310. However, once an electric current is applied to the ultrasound emitter plate 308 at specific frequency, the ultrasound emitter plate 308 vibrates and causes hydrocarbon fuel the molecules of the hydrocarbon to pass through the holes in the form of vapour. The vaporizer 300 comprises an electronic circuit (not shown) that is electrically connected with the ultrasonic emitter plate 308 for causing the ultrasonic emitter plate 308 to generate ultrasound with a frequency between 110 kHz and 220 kHz.Reference Numerals:

[0079] 100electrolyser 112electrolyser housing 114, 114'sidewall 116, 116'bottom cover 118top cover 120interior space for water reservoir 120.1headspace 120.1.1headspace for gaseous oxygen 120.1.2headspace for gaseous hydrogen 122,122'anode 122.1anode connector 124, 124'cathode 124.1cathode connector 125circle 126central axis defined by the side wall 128, 128'hydrogen outlet 130oxygen outlet 132separating wall 134openings in the separating wall 136water inlet 138electric connector 138.1electric anode connector 138.2electric cathode connector 140, 140'ultrasound generator 142, 142'sound emitting structure, cone 144electric circuit 200hydrogen fuel enhancer 210mixing stage 212compressor stage 214ionizing stage 220annular mixing chamber 222vaporized fuel inlet 224hydrogen inlet 226cylindrical outer mixing chamber wall 228opposed dual cone inner mixing chamber wall 230compressor housing 232compressor wheel 234compressor diffuser 236compressor shaft 238compressor drive, DC motor, brushless motor 240ionizer housing 240.1cylindrical upstream portion of the ionizer housing wall 240.2dome shaped downstream portion of the ionizer housing, ionizer housing front wall 240.3insulating housing liner 240.4ionizer chamber 242outer ionizing electrode, tube-shape ionizing electrode 242.1reduced diameter upstream portion of outer ionizing electrode 242.2full diameter downstream portion of outer ionizing electrode 244inner ionizing electrode 244.1inner ionizing electrode body 244.2cylindrical wall portion of inner ionizing electrode body 244.3dome-shaped front portion of inner ionizing electrode body 246mixed gas passageway 248buffer space 250ionized mixed fuel outlet 300hydrocarbon fuel vaporizer 302hydrocarbon fuel reservoir 304hydrocarbon fuel reservoir side wall 306hydrocarbon fuel reservoir outlet 308ultrasound emitter plate 310holes in emitter plate 400combustion engine

Claims

1. Electrolyser (100) comprising an electrolyser housing (112) enclosing an interior space that is adapted for containing a water reservoir, said electrolyser housing (112) comprising a side wall (114) and a top cover (118) and a bottom cover (116) that are tightly connected to the side wall (114), said electrolyser further comprising a plurality of elongate electrodes (122, 124) extending from the bottom cover (116) or the top cover (118) into the interior space enclosed by the electrolyser housing (112), wherein the electrodes (122, 124) are electrically isolated from the electrolyser housing (112) and are electrically connected to electric conductors for feeding DC current to the electrodes, wherein the electric connections are configured to connect electrodes acting as cathodes (124) to negative voltage terminal of a DC electric power source and to connect electrodes acting as anodes (122) to a positive voltage terminal of a DC electric power source.

2. Electrolyser (100) according to claim 1, wherein the electrodes extend in parallel to a central axis of the side wall (114) of the electrolyser housing (112).

3. Electrolyser (100) according to claim 1 or 2, wherein the electrodes extend from the bottom cover (116) into the interior space enclosed by the electrolyser housing (112).

4. Electrolyser (100) according to at least one of claims 1 to 3, wherein at least some of the electrodes (122, 124) are tube-shaped.

5. Electrolyser (100) according to at least one of claims 1 to 4, wherein the cathodes (124) are tube shaped and each enclose a lumen and wherein the anodes (122) are co-axially arranged with the cathodes (124), each anode (122) being arranged within the lumen of a respective cathode.

6. Electrolyser (100) according to at least one of claims 1 to 5, wherein the electrodes are arranged along at least one circle around a central axis of the side wall (114) of the electrolyser housing (112).

7. Electrolyser (100) according to claim 6, wherein the electrodes are equally spaced along the at least one circle.

8. Electrolyser (100) according to at least one of claims 1 to 7, further comprising an ultrasound generator that is configured and arranged for emitting ultra sound into the interior space enclosed by the electrolyser housing (112).

9. Electrolyser (100) according to claim 8, wherein the ultrasound generator is mechanically connected to a cone extending into the interior space enclosed by the electrolyser housing (112).

10. Electrolyser (100) according to at least one of claims 1 to 9, further comprising a separating wall (132) that divides the water reservoir enclosed by the side wall (114) into an inner reservoir enclosed by the separating wall (132) and an annular outer water reservoir extending radially between the separating wall (132) and the side wall (114), wherein the separating wall (132) comprises openings (134) providing a fluid connection between the inner water reservoir and the outer water reservoir and wherein the cathodes (124) are arranged in the inner water reservoir and the anodes (122) are arranged in the outer water reservoir or vice versa.

11. Electrolyser (100) according to claim 10, wherein the separating wall (132) is connected to the top cover (118) to thus separate the two gas-filled headspaces from one another.

12. Electrolyser (100) according to at least one of claims 1 to 11, further comprising an electric circuit (144) that produces voltage pulses with a frequency between 100 Hz and 200 kHz and that is connected to the cathodes (124).

13. Hydrogen fuel enhancer (200) for producing hydrogen enhanced hydrocarbon fuel from hydrogen and hydrocarbon fuel, wherein the hydrogen fuel enhancer (200) comprises a mixing stage (210) for mixing hydrogen and hydrocarbon fuel and a ionizing stage (214) that is at least indirectly fluid-connected to the mixing stage (210) and that is configured to ionize a mixture of hydrogen and hydrocarbon fuel, wherein the mixing stage (210) comprises a hydrogen inlet (224), a hydrocarbon fuel inlet (222) and a mixing chamber (220), wherein the mixing stage (210) is configured for mixing hydrogen with hydrocarbon fuel and feeding the mixture of hydrogen and hydrocarbon fuel to the ionizing stage (214) and wherein the ionizing stage (214) comprises ionizing electrodes (242, 244) that are arranged opposed to each other along a passageway (246) for a gas mixture to be ionized.

14. System comprising at least one hydrocarbon fuel vaporizer (300), at least one electrolyser (100) according to at least one of claims 1 to 12, at least one hydrogen fuel enhancer (200) according to claim 13 and at least one combustion engine (400), wherein the hydrocarbon fuel vaporizer (300) and the electrolyser (100) are fluid-connected to the hydrogen fuel enhancer (200) for supplying the hydrogen fuel enhancer (200) with both, vaporized hydrocarbon fuel and hydrogen, and the wherein the hydrogen fuel enhancer (200) is fluid-connected to the combustion engine (400) for supplying the combustion engine (400) with hydrogen enhance fuel.

15. Method of producing hydrogen enhanced hydrocarbon fuel, comprising the steps of. - producing hydrogen from water by means of an electrolyser - vaporizing hydrocarbon fuel - mixing the hydrogen and the vaporized hydrocarbon fuel - compressing the mixture of hydrogen and the vaporized hydrocarbon fuel, and - ionizing the compressed mixture of hydrogen and the vaporized hydrocarbon fuel.

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