WO2025088013A1

WO2025088013A1 - Injection arrangement for an internal combustion engine

Info

Publication number: WO2025088013A1
Application number: PCT/EP2024/080029
Authority: WO
Inventors: Jacques BOUVY
Original assignee: Rh2 Sas
Current assignee: Rh2 Sas
Priority date: 2023-10-26
Filing date: 2024-10-24
Publication date: 2025-05-01
Anticipated expiration: 2026-04-26
Also published as: FR3154769A1; FR3154769B1

Abstract

The invention relates to an injection arrangement for injecting a liquid or gaseous component into a combustion chamber of an internal combustion engine having a cylinder block with one or more combustion chambers; wherein the injection arrangement has a flat parallelepipedal body with a top surface and a bottom surface and surrounding outer edges; wherein said flat parallelepipedal body comprising a first top-to-bottom cutout for each combustion chamber forming respective inner edges between the top surface and the bottom surface of the flat parallelepipedal body; wherein, for each combustion chamber, the flat parallelepipedal body comprises a first channel arranged to provide a fluidic communication between a liquid or gaseous component first feeding opening in the outer edge and at least one liquid or gaseous component first injection opening in the inner edge of said combustion chamber. The invention also relates to the uses of such an injection arrangement, as well as a method for modifying a reciprocating internal combustion engine.

Description

INJECTION ARRANGEMENT FORAN INTERNAL COMBUSTION ENGINE

Technical field

[0001] The present invention generally relates an injection arrangement allowing to adapt an existing reciprocating internal combustion engine (design) to be adapted to inject one or more additional liquid or gaseous components into the engine’s combustion chamber(s) without significant modification of the engine, the uses of such injection arrangements and a corresponding method to adapt an existing reciprocating internal combustion engine (design).

Background Art

[0002] Two- and four-stroke reciprocating internal combustion engines are well known and generally comprise an engine casing generally comprising an engine or cylinder block and a cylinder head mounted to its top; a crankshaft rotatable about a crankshaft axis; one or more cylinders arranged inside said engine casing; a piston arranged inside each cylinder to movably reciprocate along a reciprocating axis between a top dead center (TDC) position distal from said crankshaft and a bottom dead center (BDC) position proximal to said crankshaft. The reciprocating piston is operatively connected to the crankshaft such that it imparts a rotational movement to the crankshaft. Furthermore, the engine also comprises a combustion chamber defined within said cylinder arranged in the engine casing and a head of the piston opposite of said crankshaft, at least one air intake valve and one exhaust valve per cylinder, means for feeding fuel into said combustion chamber, at least one spark plug per cylinder, if the engine is based on sparked ignition of the fuel air mixture, and generally an engine control unit for controlling the operation of the engine.

[0003] As an example, four-stroke engines with direct fuel injection operate in a cycle with four consecutive strokes and repetitive cycles, said stroke being the following:

[0004] Intake stroke: the piston starts to move downward from the top dead center to bottom dead center, the intake valve opens, and air enters the combustion chamber. [0005] Compression stroke: the piston moves back from bottom dead center to top dead center and compresses the air inside the cylinder and both the pressure and temperature inside the combustion chamber rise.

[0006] Combustion stroke (power stroke): generally, at the end of the compression stroke (before the piston reaches the top dead center) to very early in the combustion stroke, the fuel injectors start to inject fuel inside the combustion chamber. At some point, the fuel either spontaneously auto-ignites (compression ignition) or is ignited by a spark from a spark plug (sparked ignition). The fuel-air mixture combustion produces a pressure on the piston head and pushes the piston downward, thereby transmitting the energy to the rotating crankshaft.

[0007] Exhaust stroke: after the piston hits the bottom of cylinder (bottom dead center), the piston starts to move upward, the exhaust valve opens and the sweep effect of the piston causes the exhaust gases to leave the combustion chamber towards the exhaust system and finally to the atmosphere.

[0008] Two and four stroke reciprocating internal combustion engines have been largely operated with liquid or gaseous hydrocarbon fuels, but due to more stringent regulations regarding environmental considerations, such as unwanted carbon footprint, alternative fuels, such as hydrogen, as sole fuel or at least as partial replacement for hydrocarbon fuels, seem to be a solution to avoid or at least reduce the release of carbon oxides and unburned hydrocarbons.

[0009] Recently, WO 2023/152295 A1 has proposed to operate a four-stroke reciprocating internal combustion engine using hydrogen as a fuel with the additional controlled injection(s) of water to the combustion chamber(s) in order to optimize hydrogen combustion, reduce NOx production, reduce the risk of knocking, increase torque and efficiency.

[0010] However, separately injecting more than one component (fuel, oxidizer or inert constituent) into the combustion chamber requires the existence and thus the placement of an additional injector per combustion chamber, which in turn generally demands for significant modifications to the configuration of an engine due among others to the presence of the other required elements, such as two or more intake and exhaust valves with their actuating arrangements, a fuel injector, a spark plug in case of sparked ignition, etc. which need to be foreseen within the cylinder head of the engine casing. Depending on the diameter of the cylinders and the number of intake and exhaust valves, the location of an additional injector often becomes problematic or even impossible and would therefore require major design modifications at least to the cylinder head and its elements. For example, US 9,022,006 B2 proposes to increase the number of injection sites and to evenly spread them out all around the combustion chamber but requires modification of the cylinder housing.

[0011] Such design modifications are however not only complex and timeconsuming, but will often amount to developing an entirely new engine, as major modifications to the cylinder head are likely to entail still further changes, not only in the design, but also in the engine’s characteristics.

[0012] Furthermore, the need to modify the design of major part of the engine casing make such an approach largely unusable for retrofitting existing engines to an operation with an additional injection of a component, which had not been included in the initial design of the engine.

[0013] Even in case a redesigned part such as a redesigned cylinder head accommodating an additional injector would be possible for an existing engine, it would nevertheless require the replacement of major parts of the engine with new parts and thus significantly add to the costs and the complexity of retrofitting.

Technical problem

[0014] It is an object of the present invention to provide an injection arrangement for a reciprocating internal combustion engine, which allows to inject at least one (additional) liquid or gaseous component, such as fuel, oxidizer or inert component, into the combustion chamber(s) of said engine without requiring additional space within the cylinder head, without requiring a redesign of the cylinder head and which injection arrangement may be easily mounted to an existing engine, e.g. for retrofitting an engine to run on more than one fuel or to be operated with more than one injected component, be it fuel oxidizer or other liquid or gaseous component.

General Description of the Invention

[0015] In order to overcome the above-mentioned problems, the present invention proposes, in a first aspect, an injection arrangement for injecting a liquid or gaseous component into a combustion chamber of an internal combustion engine having a cylinder block with one or more combustion chambers; wherein the injection arrangement has a flat parallelepipedal body with a top surface and a bottom surface and surrounding outer edges; wherein said flat parallelepipedal body comprising a first top-to-bottom cutout for each combustion chamber forming respective inner edges between the top surface and the bottom surface of the flat parallelepipedal body; wherein, for each combustion chamber, the flat parallelepipedal body comprises a first channel arranged to provide a fluidic communication between a (at least one) liquid or gaseous component first feeding opening in the outer edge and at least one liquid or gaseous component first injection opening in the inner edge of said combustion chamber.

[0016] In a second aspect, the invention aims at a reciprocating internal combustion engine having a cylinder block with one or more combustion chambers and a cylinder head, which comprises one or more injection arrangements as disclosed in relation with the first aspect, mounted between said cylinder block and said cylinder head, if deemed necessary or helpful with means of one or more interlaying cylinder gaskets.

[0017] In a third aspect, the invention pertains to the use of an injection arrangement as described in the first aspect, for adapting an existing reciprocating internal combustion engine with one or more combustion chambers, such as a gasoline or diesel engine, to the injection of one or more additional (to the original fuel, such as gasoline or diesel) liquid or gaseous component into each of said combustion chambers or two or more alternative liquid or gaseous components, such as hydrogen and water, comprising the tight placement of said injection arrangement between the cylinder block and a cylinder head of said reciprocating internal combustion engine, if deemed necessary or helpful with means of one or more interlaying cylinder gaskets.

[0018] A fourth aspect of the invention relates to the use of an injection arrangement as disclosed in the first aspect, mounted between the cylinder block and a cylinder head of said reciprocating internal combustion engine, such as a gasoline or diesel engine, if deemed necessary or helpful with means of one or more interlaying cylinder gaskets, for operating said engine with separately injected hydrogen and water, wherein the hydrogen is preferably injected through said injection arrangement, e.g. such as described in WO 2023/152295 A1.

[0019] Finally, as a fifth aspect, the invention discloses a method for converting a reciprocating internal combustion engine having a cylinder block with one or more combustion chambers and a cylinder head to allow for its operation with at least one additional gaseous or liquid component fed to said combustion chambers, the method comprising the steps of:

- removing the fastening means between cylinder block and cylinder head to separate the cylinder head from the cylinder block, if applicable, removing the cylinder gasket;

- placing an injection arrangement as described in relation with the first aspect onto the cylinder head by aligning the first cutouts with the combustion chambers of the cylinder block, optionally by first inserting a cylinder gasket on the cylinder block;

- placing the cylinder head onto the injection arrangement, by aligning the first cutouts with the combustion chambers of the cylinder block, optionally by inserting a further cylinder gasket between the injection arrangement and the cylinder head; and

- fastening the cylinder head and the injection arrangement to the cylinder block by said fastening means;

- connecting a first or further source of pressurisable source of additional gaseous or liquid component to the first or further feeding opening of the injection arrangement.

[0020] Although each first channel may be connected to only one first injection opening within the inner edge of each respective combustion chamber, it might be advantageous in certain cases, e.g. for the injection of higher quantities and/or in shorter times, that each first channel comprises more than one first injection opening, such as 2 to 10, preferably 3 to 5 first injection openings in the inner edge of said combustion chamber. In other words, the first channel within the injection arrangement comprises at least one or more branch-off( segments, each leading to a first injection opening within the inner edge of each respective combustion chamber. In such cases, said plurality of first injection openings are distributed either evenly or unevenly along the inner edge of said combustion chamber, advantageously they are evenly distributed along the inner edge. Furthermore, in some embodiments, depending on the nature or state of the liquid or gaseous component to be injected, and wherein the injection into the combustion chamber is intended to be essentially simultaneous, it is advantageous to keep the (travel) distance from the first feeding opening in the outer edge to each of two or more liquid or gaseous component first injection openings in the inner edge of said combustion chamber of an identical or very similar length. Alternatively, it might be desirable to slightly stagger the times of actual injection into the combustion chamber (without the need for multiple timed injections at the injector or even for a further channel with an additional injector for the same liquid or gaseous component) among the two or more injection openings, e.g. to obtain a better distribution of the liquid or gaseous component within the combustion chamber. In such cases, the first channel and its branch-off segments may be configured such that the distances between the feeding opening and the respective injection opening are of correspondingly staggered length.

[0021] Surprisingly, the inventors found that providing more first injection openings does not necessarily result in a better and/or more even distribution of the first component within the distribution chamber, at least not if said first component is a gaseous component. Hence, in embodiments where the first component is gaseous, such as e.g. hydrogen or oxygen, the provision of only one first injection opening within the inner edge of each respective combustion chamber might be preferred.

[0022] As one of the uses of the injection arrangement of the first aspect is to convert an existing engine to accommodate an additional injection without major overhaul of the cylinder head design, the height or thickness of the flat parallelepipedal body is generally kept to a minimum while still allowing the integration of the first channels with their respective injection and feeding openings. In practice, the flat parallelepipedal body has a top-to-bottom height between top and bottom surfaces of 1 to 12 mm, preferably of 2 to 9 mm, more preferably 3 to 7 mm, such as from 3.5 to 4.5 mm.

[0023] While adding an injection arrangement of the invention between the cylinder block and cylinder head even as thin as that will impact the compression rate, this may be found acceptable (or even desirable) or not. In the latter case, it may be advantageous to replace the pistons with slightly higher ones or to shave off a fraction or the total height of the injection arrangement from the top of cylinder block and/or the bottom of the cylinder head before installation.

[0024] The size of the first openings is chosen to allow for appropriate quantities of the first liquid or gaseous components to be injected within the injection timings of the engine. Furthermore, if the first gaseous or liquid component is flammable it might be desirable or necessary to avoid the flame front and/or the back-pressure from entering the injection opening. This can at least partially be achieved for example by limiting the size or cross-section of the first injection openings. Hence, depending on the nature, state and pressure of the first gaseous or liquid component, the cross-section of each first injection opening in the inner edge of said combustion chamber may for example be from 0.05 to 20 mm², preferably from 0.2 to 7 mm², such as from 0.75 to 3.25 mm². Additionally or alternatively, to avoid the flame front and/or back-pressure from substantially entering the injection opening, the first channel, advantageously proximal to the at least one liquid or gaseous component first injection opening, may also comprise or be equipped with a check valve or one-way valve, such as back-pressure check valves, e.g. swing check valves, butterfly check valves, etc. Most preferably, in view of their size, the first channel may comprise a fixed-geometry passive check valve, such as e.g. those described in US 1 ,329,559, with 2 to 12 flow-control segments, such as from 4 to 8 flow-control segments, depending on the desired degree of back-flow regulation effect. A further advantage of such fixed-geometry passive check valves is that they comprise no moving parts and are thus not subject to wear and are generally durable and maintenance-free. In cases where the first channel comprises more than one liquid or gaseous component first injection opening, each may be associated with a separate upstream check valve or a check valve, i.e. within the branch-off segment, or one check valve may be provided for more than one first injection opening (or for all first injection openings of said first channel), i.e. it may be provided within the first channel upstream of a (or upstream of all) branch-off segment within the first channel.

[0025] A notable advantage of using check valves and in particular fixed- geometry passive check valves, is that, even if their efficiency is not perfect, it would allow the use of low-pressure injectors, so-called port (fuel) injectors, connected to the first feeding opening for controlling the injection of the first component. Such port injectors are more common, less fragile and less expensive than high pressure injectors. Moreover, a further advantage, and not the least for certain applications, is that as these port injectors work at comparatively low pressure (e.g. max. 10 bar), the source of the first component does not need to be kept under high pressure or conversely will still be usable when the pressure drops below the pressure required by high-pressure injectors (typically working at 30 to 40 bar), which means that for (mobile) applications relying e.g. on a gaseous first component contained in pressurized cylinders, such as H2 or O2, that the cylinders can be emptied more/used longer before being empty.

[0026] Hence, in some embodiments, the injection arrangement comprises an injector mounted in fluidic connection to the first feeding opening of each channel, preferably a conventional low-pressure port injector. An alternative option would be to use two types of injectors for injecting the first component: a port type injector for a first injection and a high-pressure type injector for a second injection. In such cases, the low-pressure first injection might be the main injection and the high-pressure second injection might only represent a fraction of the quantity of the first injection, preferably 1 to 10 wt.-%, more preferably 2 to 8 wt.-%, such as 3 to 5 wt.-% of the total mass of injected first component. The order of the first and second injections may of course be inverted if desired. Such a double injector type configuration (separate or within one housing) may be advantageously used for injecting gaseous first components, such as in particular hydrogen. These two injector types are preferably connected to the same first channel of the injector arrangement. To connect two separate injectors, the first feeding opening may be provided with an additional external Y-manifold mounted between the first feeding opening and each of the two injectors, Alternatively, the (or each) first channel comprises two first feeding openings, each of said first feeding openings (of a same first channel) being arranged for mounting an injector thereto, such as in particular a conventional low-pressure port injector and a conventional high- pressure injector. In advantageous embodiments, check valves as described above may also be used to protect the injector(s) from unwanted and possibly too high transient back-pressures from the combustion chamber, independently or additionally to their role in avoiding a propagation of the flame front within the injection arrangement.

[0027] In an advantageous embodiment, the injection arrangement is configured such that the first feeding opening of each channel is adapted for being connected to a first pressurisable source of the first gaseous or liquid component, either directly or preferably through an additional injector as described above. An important benefit of the invention is that any further means required for providing the first gaseous or liquid component in the state appropriate for injection, even the above-mentioned injectors, may be deported to the exterior of the engine and located relatively freely on the side of the cylinder block or even at any other location within relative proximity of the engine. An injection arrangement according to the invention does therefore not require any substantial modification of the cylinder block or cylinder head of the internal combustion engine.

[0028] The shape of the cross-section of the first openings is generally chosen to favor a good distribution of the first liquid or gaseous component in the combustion chamber upon injection. While a number of regular or irregular shapes might be appropriate, the at least one liquid or gaseous component first injection opening in the inner edge of said combustion chamber preferably has a round, oval or polygonal section.

[0029] The first channel is generally configured within the parallelepipedal body such that it is essentially parallel to its top and bottom surfaces. However, this does not mean that some segments of the channel, e.g. end segments near the injection opening and/or near the feeding opening may not be angled vertically towards the bottom or the top surfaces, such as at angles of +/- 30 °, preferably +/- 15 °, more preferably +/- 7 °, while still having their opening in the respective edge.

[0030] Similarly, an end segment of the first channel upstream of the at least one liquid or gaseous component first injection opening may be non-perpendicular to a tangent to said inner edge in the inner edge of said combustion chamber, meaning that the injected first liquid or gaseous component is not injected towards the center of the combustion chamber, but rather to one side thereof, thereby creating or sustaining a swirl motion within the combustion chamber. Preferably, said end segment of the first channel upstream of the at least one liquid or gaseous component first injection opening forms an angle of 3 to 65 °, preferably of 5 to 45 °, more preferably of 7 to 20 °, to said tangent within a plan parallel to the top or bottom surfaces of the injection arrangement.

[0031] While the injection arrangement disclosed herein may be made of any appropriate material able to resist the pressures, temperatures and friction within such an engine, said injection arrangement is generally made of metal or metal alloys, preferably steel or aluminum, or made of or comprising ceramics.

[0032] In practice, the flat parallelepipedal body of the injection arrangement will often closely match the configuration and shape of the top of the cylinder block and the bottom of the cylinder head. Hence, it will generally comprise second top- to-bottom cutouts for cylinder head to cylinder block fastening means, cylinder head to cylinder block lubricant circulation and/or cylinder head to cylinder block coolant circuit, etc.

[0033] Depending on the intended operation of the internal combustion engine, it might be desirable or necessary to provide for the possibility to inject still further liquid or gaseous components, such as a second, a third, etc. One easy possibility to allow for this would be to stack two or more injection arrangements as described herein for injecting at least one further liquid or gaseous component into the combustion chamber of the internal combustion engine.

[0034] In further embodiments, the invention however also provides for injection arrangements which flat parallelepipedal body comprises, for each combustion chamber, at least one further (second, third, ... ) channel arranged to provide a fluidic communication between at least one further (second, third, ... ) liquid or gaseous component feeding opening in the outer edge and one or more further (second, third, ... ) liquid or gaseous component injection openings in the inner edge of said combustion chamber. Hence, in a further embodiment an injection arrangement according to the invention may provide for two (or more) additional liquid or gaseous components to be injected in the combustion chambers of the modified engine with only one injection arrangement.

[0035] When further liquid or gaseous component injection openings are located in the inner edge of said combustion chamber, these may be placed at a different height than the first liquid or gaseous component injection openings. However, if it is desired to situate all injection openings at the same height, the first and further channels may be placed at the same height within the parallelepipedal body, or the end segments downstream the injection opening may be angled vertically with corresponding angles such that the injection openings are at a same height.

[0036] Also, for the reasons explained in the context of the first channel, the injection arrangement may be configured such that each further (second, third, ... ) channel comprises only one or, if deemed advantageous, more than one, such as from 2 to 10, preferably from 3 to 5 further injection openings in the inner edge of said combustion chamber, wherein said further (second, third, ... ) injection openings are preferably evenly distributed along the inner edge of said combustion chamber, e.g. in alternation with said first injection openings.

[0037] It is understood that such further (second, third, ... ) channels, feeding openings and injection openings, end segments, etc. may also independently from one another comprise any or all of the features described in the context of the first channel, first feeding opening, first injection opening, end segment, etc., such as single or multiple injection openings with identical or different cross-section shapes and/or sizes, check valves, etc.

[0038] As already mentioned, the gaseous or liquid first component may be a fuel, an oxidizer or even an inert component not participating in the combustion reaction(s). As the present invention allows to inject at least one further component (or at least two different components by replacing the original fuel with another component), operating a diesel or gasoline engine with hydrogen and water, such as described in WO 2023/152295 A1 , can be easily implemented with limited costs. But the different uses of injection arrangements as described herein are manifold, as such an injection arrangement can be used for example to inject (additional) oxygen, thereby allowing to inject higher quantities of fuel, be it conventional (fossil) liquid fuels or more CO2-neutral gaseous or liquid fuels. Moreover, by operating engines modified with the injection arrangement of the invention with compressed oxygen only, instead of air, the engine could operate in any speed or load without (the possibility of) producing any NOx.

[0039] Moreover, by injecting hydrogen as a first component and oxygen as a further component through corresponding first and further channels in an injection arrangement of the present invention (plus optionally by injecting any additional component, such as water, through the original injector), it would be possible to get rid of the admission valves and corresponding commands from within the cylinder head, thereby reducing the number of moving parts, corresponding maintenance and repair and, besides, freeing space for implementing further modifications and additions susceptible of further assisting a reliable yet clean, CO2-neutral and NOx-free operation of reciprocating internal combustion engines.

[0040] As can be seen from the above, a major advantage of the present invention is the fact that although it allows to substantially change the operation of a reciprocating internal combustion engine by permitting the use of at least one additional injected component (and by possibly replacing the existing injected component with another), it does not require any redesign of the engine’s cylinder block or even cylinder head, all further additional parts, such as the additional injector(s), liquid or gaseous component containers, control unit, etc., may be relatively freely installed at the outside of the (original) engine, making it ideal for retrofitting purposes. Moreover, the installation, configuration and maintenance can be made by any mechanic with only basic additional training or instructions.

Brief Description of the Drawings

[0041] Preferred embodiments of the invention will now be described, by way of example, with reference to the accompanying drawings in which:

[Fig. 1] is a perspective view of an embodiment of an injection arrangement according to the first aspect of the invention;

[Fig. 2] is a top view of the embodiment of an injection arrangement according to the first aspect of the invention as shown in Fig. 1 ;

[Fig. 3] (a) - (c) are schematic cross-sections of the body of different embodiments of injection arrangements having one liquid or gaseous component first feeding opening and one (a), three (b) or four (c) liquid or gaseous component first injection openings; and

[Fig. 4] is a schematic cross-section of the body of a still different embodiment of an injection arrangement for injecting two different (fuel, oxidizer, etc.) components, said injection arrangement having one first channel and one further channel with their corresponding liquid or gaseous component first feeding opening and liquid or gaseous component first injection opening. [0042] Further details and advantages of the present invention will be apparent from the following detailed description of several not limiting embodiments with reference to the attached drawings.

Description of Preferred Embodiments

[0043] Fig. 1 shows an example of an injection arrangement 100 in perspective view. Said injection arrangement has a roughly parallelepipedal body with a top surface 110 and a bottom surface (120, not visible in Fig. 1 ) and surrounding outer edges 125. For each cylinder or combustion chamber of the reciprocating internal combustion engine (a six-cylinder engine in the illustrated case), the injection arrangement 100 comprises a top-to-bottom cutout 130 whose dimensions and shape match those of the cross-section of the combustion chamber at the top of the cylinder block. These first top-to-bottom cutouts 130 each form an inner edge 135.

[0044] The injection arrangement illustrated in Fig. 1 comprises for each combustion chamber a first channel 140 (actually not visible, thus shown as a dotted line) provided within the body of the injection arrangement with an opening in the outer edge 125, i.e. the liquid or gaseous component first feeding opening 141 , and an opening within the inner edge 135 of the combustion chamber first top-to-bottom cutout 130, wherein the feeding opening and the injection opening are in fluidic connection through the first channel 140.

[0045] The injection arrangement in Fig. 1 also comprises further top-to-bottom cutouts, called second top-to-bottom cutouts 150 at different location having different shapes and sizes. These second top-to-bottom cutouts 150 may serve e.g. as a passage for cylinder head to cylinder block fastening means, for cylinder head to cylinder block lubricant circulation and/or for cylinder head to cylinder block coolant circuit.

[0046] Fig. 2 is a top view of the embodiment of an injector arrangement 100 of Fig. 1 , wherein the same numerals refer to the same features and the dotted lines show the position of the first channels within the body of the injection arrangement, further showing for one cylinder the top of the combustion chamber 200 within the cylinder head (not shown) and a two-valve admission manifold 210 and a two- valve exhaust manifold 220 installed within the cylinder head (not shown). [0047] Fig. 3 (a) - (c) are schematic cross-sections of the body of different simplified embodiments of injection arrangements 100 for a mono-cylinder internal combustion engine being configured for injecting one additional (first) component (additional to the engine original injections) and having a first channel 140 with an end segment 145, one liquid or gaseous component first feeding opening and one (a), three (b) or four (c) liquid or gaseous component first injection openings.

[0048] The embodiments shown in Fig. 3 (b) and (c) therefore comprise one or more branch-offs, one three-way branch-off in the example of embodiment (b) and five two-way branch-offs in the example of embodiment (c). The number of branch-offs in embodiment (c) results from the fact that the first channel comprises a circular connection segment. Such a configuration may be advantageous if the number of injection openings is three or more, especially in a circumferentially evenly distributed configuration, as the liquid or gaseous component may reach the respective injection opening by more than one way.

[0049] Fig. 4 is a schematic cross-section of the body of a still different embodiment of an injection arrangement 100 for a mono-cylinder internal combustion engine being configured for injecting two additional different components (fuel, oxidizer, etc.), said injection arrangement having one first channel 140 and one further channel 160 with their corresponding liquid or gaseous component first feeding openings 141 , 161 and liquid or gaseous component first injection opening 142, 162.

Legend:

100 injection arrangement

110 top surface

120 bottom surface

125 outer edge

130 first top-to-bottom cutout

135 inner edge

140 first channel (within the body of the injection arrangement)

141 liquid or gaseous component first feeding opening

142 liquid or gaseous component first injection opening

145 end segment of the first channel

150 second top-to-bottom cutouts further channel further liquid or gaseous component feeding opening further liquid or gaseous component injection opening end segment of the further channel roof of the combustion chamber two-valve admission manifold two-valve exhaust manifold

Claims

1. An injection arrangement for injecting a liquid or gaseous component into a combustion chamber of an internal combustion engine having a cylinder block with one or more combustion chambers; wherein the injection arrangement has a flat parallelepipedal body with a top surface and a bottom surface and surrounding outer edges; wherein said flat parallelepipedal body comprising a first top-to-bottom cutout for each combustion chamber forming respective inner edges between the top surface and the bottom surface of the flat parallelepipedal body; wherein, for each combustion chamber, the flat parallelepipedal body comprises a first channel arranged to provide a fluidic communication between a liquid or gaseous component first feeding opening in the outer edge and at least one liquid or gaseous component first injection opening in the inner edge of said combustion chamber.

2. The injection arrangement as claimed in claim 1 , wherein each first channel comprises only one first injection opening in the inner edge of said combustion chamber for injection of a gaseous component.

3. The injection arrangement as claimed in claim 1 , wherein each first channel comprises 2 to 10, preferably 3 to 5 first injection openings in the inner edge of said combustion chamber, wherein said first injection openings are preferably evenly distributed along the inner edge of said combustion chamber.

4. The injection arrangement as claimed in any one of claims 1 to 3, wherein the cross-section of each first injection opening in the inner edge of said combustion chamber is from 0.05 to 20 mm², preferably from 0.2 to 7 mm², more preferably from 0.75 to 3.25 mm².

5. The injection arrangement as claimed in any one of claims 1 to 4, wherein the flat parallelepipedal body has a top-to-bottom height between top and bottom surfaces of 1 to 12 mm, preferably 2 to 9 mm, more preferably 3 to 7 mm, most preferably from 3.5 to 4.5 mm.

6. The injection arrangement as claimed in any one of claims 1 to 5, wherein the at least one liquid or gaseous component first injection opening in the inner edge of said combustion chamber has a round, oval or polygonal section.

7. The injection arrangement as claimed in any one of claims 1 to 6, wherein an end segment of the first channel upstream of the at least one liquid or gaseous component first injection opening is non-perpendicular to a tangent to said inner edge in the inner edge of said combustion chamber, preferably said end segment of the first channel upstream of the at least one liquid or gaseous component first injection opening forms an angle of 3 to 65 °, preferably of 5 to 45 °, more preferably of 7 to 20 °, to said tangent.

8. The injection arrangement as claimed in any one of claims 1 to 7, wherein the first channel comprises a check valve or one-way valve, preferably a backpressure check valve, more preferably a swing check valve, a butterfly check valve or a fixed-geometry passive check valve.

9. The injection arrangement as claimed in any one of claims 1 to 8, wherein the first feeding opening of each channel is configured for connection to a first pressurisable source of the gaseous or liquid component.

10. The injection arrangement as claimed in any one of claims 1 to 9, wherein the first feeding opening of each first channel is arranged for mounting an injector thereto, preferably a conventional low-pressure port injector.

11. The injection arrangement as claimed in any one of claims 1 to 9, wherein the first channel comprises two first feeding openings, each of said first feeding openings being arranged for mounting an injector thereto, preferably a conventional low-pressure port injector and a conventional high-pressure injector.

12. The injection arrangement as claimed in any one of claims 1 to 11 , wherein said injection arrangement is made of metal or metal alloys, preferably steel or aluminum, or made of or comprising ceramics.

13. The injection arrangement as claimed in any one of claims 1 to 12, wherein the flat parallelepipedal body comprises second top-to-bottom cutouts for cylinder head to cylinder block fastening means, cylinder head to cylinder block lubricant circulation and/or cylinder head to cylinder block coolant circuit.

14. The injection arrangement as claimed in any one of claims 1 to 13, for injecting at least one further liquid or gaseous component into the combustion chamber of the internal combustion engine, wherein, for each combustion chamber, the flat parallelepipedal body comprises at least one further channel arranged to provide a fluidic communication between at least one further liquid or gaseous component feeding opening in the outer edge and one or more further liquid or gaseous component injection openings in the inner edge of said combustion chamber.

15. The injection arrangement as claimed in claim 14, wherein each further channel comprises 2 to 10, preferably 3 to 5 further injection openings in the inner edge of said combustion chamber, wherein said further injection openings are preferably evenly distributed along the inner edge of said combustion chamber, in alternation with said first injection openings.

16. A reciprocating internal combustion engine having a cylinder block with one or more combustion chambers and a cylinder head, comprising an injection arrangement as claimed in any one of claims 1 to 15 mounted between said cylinder block and said cylinder head.

17. Use of an injection arrangement as claimed in any one of claims 1 to 15, for adapting an existing reciprocating internal combustion engine, such as a gasoline or diesel engine, with one or more combustion chambers to the injection of one or more additional liquid or gaseous components into each of said combustion chambers, comprising the tight placement of said injection arrangement between the cylinder block and a cylinder head of said reciprocating internal combustion engine.

18. Use of an injection arrangement as claimed in any one of claims 1 to 15 mounted between the cylinder block and a cylinder head of said reciprocating internal combustion engine, such as a gasoline or diesel engine, for operating said engine with separately injected hydrogen and water, wherein the hydrogen is preferably injected through said injection arrangement.

19. A method for converting a reciprocating internal combustion engine having a cylinder block with one or more combustion chambers and a cylinder head to allow for its operation with at least one additional gaseous or liquid component fed to said combustion chambers, the method comprising the steps of:

- placing an injection arrangement as claimed in any one of claims 1 to 15 onto the cylinder head by aligning the first cutouts with the combustion chambers of the cylinder block, optionally by first inserting a cylinder gasket on the cylinder block;