NL1013325C2 - Fuel hydrocarbon reforming device of fuel injection system for internal combustion engine consists of multiple co-axial tubes and helical tube used for generating vortex flow of fuel - Google Patents

Abstract

Reaction chamber (8) consists of multiple co-axial tubes (14,14',15,15') and helical tube (10) used for generating vortex flow of fuel. Helical grooves on ribs are formed in the helical tube. A housing (9) surrounds the helical tube. Heat exchanger is provided between reaction chamber and heat source. An Independent claim is also included for fuel reforming method.

Description

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Apparatus for reforming hydrocarbons from a fuel into one or a mixture of a fuel and oxygen-carrying gas to be formed.

The invention relates to a device for the thermal and catalytic or non-catalytic reforming of hydrocarbons of a fuel in one or a further mixture of a fuel and oxygen-carrying gas, which is provided with a means for supplying an atomized fuel or fuel / air mixture, a reaction chamber with or without one or more catalysts, an outlet from the reaction chamber to a combustion engine, and heat exchanger means between the reaction chamber and the combustion gas discharge from the combustion engine.

Such a device is known from US-A-3,828,736.

This known device is intended to be used with a fuel, for example gasoline, free from additives, such as cyclic hydrocarbons and lead compounds, necessary to obtain a high octane content. In addition, this known device is complicated in the sense that a measured volume of exhaust gases must be supplied to a nebulized fuel / air mixture before the mixture can be supplied to the reaction chamber, and that before the reformed gas can be supplied to a combustion engine a measured volume of air must be supplied.

The object of the invention is to provide a device which does not have the above-mentioned drawbacks, which has a relatively simple construction and which can be used with the most common fuels for motor vehicles available at the pumping stations, therefore fuels with additives. .

Accordingly, according to the invention, it is provided that the reaction chamber comprises one or more chambers, at least one location providing means for generating a vortex in at least a portion 1013325 -2- of the fuel or fuel / air mixture.

A number of advantages are obtained by vortexing the fuel / air mixture. First of all, the fuel / air mixture follows a relatively long path relative to the length of the chamber, whereby a radial distribution of the various hydrocarbon molecules is created by the vortex, and in particular the larger, heavier hydrocarbon molecules to be reformed by the centripe. 10 force force against the wall of the reaction chamber. The advantage of this is that the heat transfer from the chamber wall to the hydrocarbon molecules also takes place mainly to the larger hydrocarbon molecules to be reformed.

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A further advantage is that by transporting the larger hydrocarbon molecules along the wall of the reaction chamber in a vortex, they can be reformed not only by a thermal process and possibly also the catalytic action of the wall of the reaction chamber, but also by mechanical operation. Not only by the friction of these larger hydrocarbon molecules along the wall, a contribution is made to the reforming of these molecules, but also by the heat generated thereby as a result of the vortex.

Of great importance is the cleaning action by friction that the vortexed fuel / air mixture may have on the wall or walls of the reaction chamber. As a result, the deposits caused by the additives present in the fuel are completely or at least partly removed continuously, as a result of which the catalytic action of the wall of the reaction chamber or the catalyst applied separately thereon is not or only slowly reduced.

35

A still further advantage of this forced helicoidal flow lies in the much better mixing of the hydrocarbons with the air supplied simultaneously with the fuel, whereby a further improvement of the combustion is obtained.

In most cases simple heat exchanger means between the discharge of the combustion gases from the combustion engine and the reaction chamber suffices to obtain a sufficiently large heat transfer. The simplest embodiment is clamps 10 of the reaction chamber directly at the beginning of the exhaust or exhaust manifold. The heat transfer can be further improved by providing that the contact area between the outlet and the reaction chamber is as large as possible by, for example, shape adaptations and guiding means, and that the reaction chamber is made of a material with a sufficiently high heat conductivity coefficient. Aluminum or copper are suitable for the material to be used.

According to a first simple embodiment, provision is made for the reaction chamber to consist essentially of two or more successive pipe sections, successive pipe sections connecting to each other at an angle. The successive pipe sections connect to one another in such a way that the axes of the pipe sections are offset from one another, the upstream pipe section having a transition with the downstream pipe section which forms an approximate interface with the downstream pipe section.

Starting from circular cylindrical pipe sections, the fuel / air mixture enters the downstream pipe section directly along the inner wall thereof at a right or slightly obtuse angle with respect to the longitudinal direction of the pipe section. By this construction 35 the sucked fuel / air mixture is vortexed.

Instead of connecting successive pipe sections in this way, it is also possible to arrange an approximately circular cylindrical housing between the supply and the reaction chamber, to which the supply connects tangentially and the reaction chamber axially, and wherein blades are arranged in the housing. such that the fuel or fuel / air mixture is introduced into the reaction chamber in a vortex.

According to a further embodiment, guide bodies are provided in a reaction chamber or successive chambers thereof forcing at least part of the fuel or fuel / air mixture into a vortex. Such guide bodies have the advantage that obtaining a vortex in the mixture does not depend on abrupt pipe transitions or vane systems, whereby a more controlled flow can be obtained. An important further advantage is that with this the contact surface of the reaction chamber with the fuel / air mixture can be considerably increased, so that the reforming of the fuel can proceed faster and more fully.

Furthermore, by using guide bodies, the external shape of the reaction chamber can be simpler and it can again be adapted more easily to the shape of an exhaust or exhaust manifold.

The guide bodies may consist of simple spaced-apart guide baffles, however, preferably, the guide body is provided to be substantially a helicoidal shaped guide body or a plurality of helicoidal shaped guide bodies arranged coaxially, the guide bodies joining along the outer circumference thereof on the wall of the room or rooms.

35

According to a further elaboration, it is further provided that an area directly around the axis of the guide body or guide bodies offers a free passage over at least a part of the length of the guide body. The smaller hydrocarbon molecules already present or the ones obtained by reforming enter the vortex in this central region due to the radial distribution of the hydrocarbon molecules in size and thus in weight and can then easily be passed through the reaction chamber to the exit and then to the combustion engine. turn into.

The helicoidal guide bodies may have 10 straight planes in cross section, which may to a greater or lesser extent slope downstream in order to further increase the surface area. According to a further embodiment, however, provision is made for the guide body or guide bodies to have a curvature seen in cross section along the axis, the convex side being on the upstream side. This creates an extra swirl in the flow and thereby a better mixing of the fuel / air mixture and also a better heat transfer.

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The diameter of the helicoidal guide bodies can remain the same over the entire length, however it is also possible to increase or decrease the diameter of the reaction chamber together with that of the guide body. When adding a medium, such as water, to the mixture in the reaction chamber, it may be desirable or necessary to increase the diameter downstream. Adding water to a fuel / air mixture is known per se and serves to reduce the amount of fuel required for good combustion and to keep the temperature in the combustion chamber low with a lean mixture. In addition, the volume increase by conversion to steam contributes to the power of the engine.

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Typically, the helicoidal conductive bodies are rigidly connected to the wall of the reaction chamber to obtain better heat transfer. However, this is not the case in an embodiment where driving means are provided for driving one or more of the helicoidal guide bodies. Such an embodiment can provide a solution for a system in which the underpressure is not sufficiently large at times or can be used as an injection system, whether or not temporarily.

In order to always be able to keep the negative pressure in the reaction chamber within a certain range in the event of varying demand, it is provided according to a preferred embodiment that the reaction chamber comprises two or more chambers arranged in parallel, whereby means are provided for being able to close or open at least one of the rooms. Such means can consist of controllable valves, the control of which depends on process values to be measured. A simpler elaboration provides that the means consist of valve or valves open at predetermined negative pressure.

In addition to or instead of a tubular reaction chamber with one or more guide bodies therein, it can also be provided that at least a part of the reaction chamber consists of a helicoidally wound tube part.

Finally, according to the invention, there is also provided an embodiment in which the reaction chamber comprises an approximately round or oval chamber with a supply connecting tangentially to it for a mixture of a fuel and an oxygen carrying gas and a radially connecting discharge. In this embodiment, the fuel / air mixture enters the reaction chamber along the inner side of the outer wall of the reaction chamber, the fraction of the hydrocarbons reformed along that inner side being displaced by the centripetal force through the radial distribution to the center of the reaction chamber and can leave the reaction chamber via the discharge positioned there.

In addition, it is further possible to arrange an inner wall which runs approximately parallel to the outer wall and which is provided with passages to a central part of the reaction chamber. This additional wall serves as an additional means for transferring the heat from the exhaust gases to the fuel / air mixture and thus for a more complete reforming of the larger hydrocarbon molecules. Instead of an inner wall parallel to the outer wall, it is also possible to arrange a wall spiraling towards the center or towards the center.

In this latter embodiment, the reaction chamber can be clamped, for example, with the bottom part thereof on an exhaust manifold. The heat is then transferred via the bottom part to the outer wall and any other walls connected to the bottom part.

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While it is known that some of the materials eligible to produce the reaction chamber may have some catalytic activity in reforming the larger hydrocarbon molecules, such as, for example, iron, steel and copper, may also be used in more specific catalysts be provided. Such catalysts can be applied, for example, in a layer on the walls of the reaction chamber and / or the guide walls. Another possibility is to incorporate catalysts into porous supports and to arrange these supports against wall parts or to accommodate them in passages.

Breaking up the larger hydrocarbon molecules, which are either less or non-combustible in the combustion chamber of an engine, obtained with the device according to the invention, into smaller, more combustible molecules ensures that in the same amount of mixture of hydrocarbon and air after reforming, a larger amount of better burnable smaller hydrocarbon molecules are present, effectively obtaining a "rich" mixture. This makes it possible to supply more air to the mixture before it enters the combustion chamber, so that combustion can take place in a normal ratio and no overheating can occur due to a "lean" mixture.

Therefore, either an amount of air can be supplied to the mixture, for example via an underpressure-dependent valve system, or a smaller amount of fuel can also be initially included in the fuel / air mixture, resulting in more economical consumption.

The invention is further elucidated hereinbelow on the basis of the example given in the drawing, in which: fig. 1 schematically shows a device mounted on a manifold; Fig. 2 schematically shows an embodiment with tube parts connecting tangentially to each other; Fig. 3A, B, C schematically show two embodiments of a guide body; Fig. 4 schematically shows a further embodiment for a guide body; Fig. 5 schematically shows a two reaction chamber system; Fig. 6 schematically shows a further embodiment of a reaction chamber, and Fig. 7 schematically shows a further embodiment of a reaction chamber.

In Fig. 1, 1 indicates a combustion engine with four cylinders 2, 3, 4, 5 an inlet manifold 6 and an exhaust manifold 7 and a further exhaust pipe 8. 9 indicates a mounting plate for fitting a carburettor or another means for supplying a fuel / air mixture. From the mounting plate, a pipe section 10 conveys the mixture to the actual reaction chamber 11 and from there via a connecting pipe section 12 to the inlet manifold 6 and then the cylinders 2,3,4,5.

The actual reaction chamber 11 in the example given in Fig. 1 is packaged in a heat-resistant casing 13 within which a heat-conducting and deformable medium is arranged. Such a heat-conducting medium can for instance consist of a heat-conducting paste or aluminum or copper particles and / or platelets.

Fig. 2 shows an example with tangentially connecting pipe parts 14,15,16,17,18, the pipe part 5 14 being connected to the mounting plate 9 for the carburettor or similar member and the pipe part 19 with a fixing flange for the connection to the inlet manifold, not otherwise shown.

The pipe parts are always staggered with respect to each other, the upstream pipe part always connecting to about half of the next pipe part and wherein a curvature or as in this case a flat adjustment 21 is provided. The fuel / air mixture is vortexed again and again through this transition which tangentially connects to the next pipe section. The transition between the tube sections 18,19 is exactly opposite to the previous transitions in order to prevent the mixture from entering the inlet manifold in a vortex and possibly causing an uneven distribution of the mixture over the cylinders.

In addition, an inlet 50 is arranged on the pipe section 18, whereby additional air can be supplied to the reformed mixture. This inlet 50 also connects tangentially to the pipe section 18 and in the direction of the vortex generated there, whereby better mixing with the mixture can be obtained. The inlet can further be provided with a vacuum-dependent valve.

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The effect of the air supplied in this way is particularly noticeable at the higher speeds at which the engine can operate, for example when driving on the motorway, where the underpressure of the engine is greatest. In this way, more power and more economical consumption is realized with the same initial amount of fuel / air mixture.

The inlet 50 is also suitable, for example, for supplying a certain amount of water or water vapor to the mixture.

In this embodiment, in any case, the pipe part 16 will be fitted to the exhaust manifold, but preferably the pipe parts 16, 17 and also parts of the pipe parts 15 and 18 are thermally coupled to the exhaust manifold with a good heat-conducting envelope. The actual reaction chamber then extends over a large part of the combined length of the pipe sections. The pipe sections will already have some catalytic effect on reforming the larger hydrocarbon molecules with the most common construction materials. However, it is also possible to apply a specific catalytic material on the inside of the pipe walls.

In Fig. 3A, B, C, two guide bodies 22, 23 to be placed in a pipe section are shown. The guide body 22 is helically wound and has a diameter relative to the pipe section into which it is to be applied such that the outer circumference rests against the inner side of the pipe section 25 so as to have good thermal contact therewith.

The guide surface 26 of the guide body extends radially from the outer circumference 24 to some distance from the centerline 27, so that a free through space remains around the centerline 27. The guide surface is thereby curved in a radial direction, such that on the upstream side, arrow 28 indicates the flow direction, the guide surface is convex. This allows the lighter hydrocarbon molecules, which are formed during the reforming process, to enter the central, underpressure part of the guide 22, 23 and the tube 25 more quickly, and from there directly to the inlet manifold and combustion engine.

Fig. 3C shows a comparable guide body 23, the guide surface of which is radial in cross section with a slope towards the center line 30, which is always 1013325! -lime the flow is with.

In figure 4 a tube part 31 is shown with a number of coaxial guide bodies 32,33,34,35,36, which together also provide a free central passage 37 again. Such an embodiment has the advantage of a much larger surface area and therefore better heat transfer and catalytic action.

Fig. 5 shows an embodiment of the device with a tube part 10 'coming from a carburettor or similar member, a reaction chamber consisting of tube parts 38,39 with respective guide bodies 40,41, and a further tube part connecting to the tube parts 38,39 12 '15 through which the fuel / air mixture can be supplied to the internal combustion engine via inlet manifold.

The tube parts 38, 39 are arranged in parallel, whereby one of the tube parts can be closed by means of valves 42, 43 arranged at one or both ends. The valves are designed or switched in such a way that with a greater demand and thus a greater negative pressure, the valves open and the required fuel / air mixture can be passed through both pipe parts 38, 39. With smaller demand, the pressure drop across both tube parts 38, 39 is not great enough to generate the desired vortex, so that one tube part can suffice.

The simplest embodiment of the valves is a pressure-dependent mechanical valve, which does not require any external control. Such a valve 43 has, for example, a valve seat 51 on which flexible valve parts 52, 53, 54 are mounted with fasteners 55, 56, 57. The valve parts 52, 53, 54, which are made, for example, of sheet metal 35, are provided with a sufficient high negative pressure opened, the valve parts forming a tangential transition with the connecting pipe section. The valve can furthermore be provided with an electromagnet 58 with which the valve parts can also be kept closed and closed with an otherwise sufficiently great underpressure.

In Fig. 6 a further embodiment of a reaction chamber 44 is shown, which mainly consists of a helically-wound tube section between the tube section 10 '' connected to the carburettor or comparable member and the tube section connected to the inlet manifold. 12 ''. A further helicoid conducting body can therefore also be arranged within the reaction chamber. With this embodiment a relatively long reaction chamber can be realized over a short distance, which can therefore be fitted in its entirety on top of the exhaust manifold.

Finally, in Fig. 7 an embodiment is shown which mainly consists of a cylindrical chamber 45 with an approximately tangential inlet 10 '' 'and an axial outlet 12' ''. In the chamber 45 a cylindrical jacket 46 is provided, which is provided with openings 47 through which the lighter fraction can flow to the central part 48 and subsequently to the outlet 12 ''. In this embodiment, for proper operation, catalysts will preferably be applied both on the inside of the outer wall 49 and on the outside of the jacket 46.

1013325

Claims (23)

1. Device for the thermal and catalytic or non-catalytic reforming of hydrocarbons from a fuel into a mixture of a fuel and oxygen-carrying gas to be further formed, which is provided with a supply of an atomized fuel or fuel / air mixture, a reaction chamber with or without one or more catalysts, an outlet from the reaction chamber to a combustion engine and heat exchanger means between the reaction chamber and the combustion gas discharge of the combustion engine, characterized in that the reaction chamber is one or a plurality of chambers, wherein means are provided at at least one location for generating a vortex in at least a portion of the fuel or fuel / air mixture. 2. Device as claimed in claim 1, characterized in that the reaction chamber consists essentially of two or more successive tube parts, successive tube parts connecting to each other at an angle. 3. Device as claimed in claim 2, characterized in that the successive tube parts connect to each other such that the axes of the tube parts are staggered relative to each other, the upstream tube part having a transition with the downstream tube part which has an approximate contact with the downstream pipe section. 4. Device according to claim 1, characterized in that the reaction chamber comprises two or more chambers 30 arranged in parallel, wherein means are provided for closing or opening at least one of the chambers. 5. Device as claimed in claim 4, characterized in that the means consist of valve or valves opened at predetermined underpressure. Device according to one or more of claims 1 to 5, characterized in that the supply for the fuel or fuel / air mixture connects tangentially to the reaction chamber. 7. Device as claimed in claim 6, characterized in that an approximately circular cylindrical housing is arranged between the supply and the reaction chamber to which the supply connects tangentially and the reaction chamber axially, and wherein blades are arranged in the housing such that the fuel or the fuel / air mixture is introduced into the reaction chamber in a vortex. 8. Device according to one or more of claims 1-7, characterized in that guide bodies are arranged in a reaction chamber or its constituent chambers which vortex at least a part of the fuel or the fuel / air mixture. 9. Device as claimed in claim 8, characterized in that the guide body is essentially a helicoidally shaped guide body or consists of a number of helicoidally shaped guide bodies which are arranged coaxially. 10. Device as claimed in claim 9, characterized in that an area directly around the axis of the guide body 25 or the guide bodies offers free passage over at least a part of the length of the guide body. 11. Device as claimed in claims 9-10, characterized in that the guide body or the guide bodies have a curvature seen in cross section along the axis, the convex side being located on the upstream side. 12. Device as claimed in claims 9-10, characterized in that the guide body or guide bodies, when viewed in a direction of a point of contact of a guide body with a chamber wall, slope in the downstream direction towards the center line. 1013325 -15- Device according to one or more of claims 9-12, characterized in that the radius of the helicoidal conductive body or bodies increases in downstream direction. 5 Device according to one or more of claims 8-13, characterized in that the guide body or guide bodies adjoin the wall of the reaction chamber along its outer circumference. 10 15. Device as claimed in one or more of the claims 9-13, characterized in that drive means are provided for driving one or more of the helicoidal guide bodies. 16. Device according to claims 2-7, characterized in that at least a part of the reaction chamber consists of a helicoidal wound tube part. Device according to one or more of claims 1 to 3, characterized in that the reaction chamber comprises an approximately round or oval chamber with a supply connecting a tangentially thereto for a mixture of a fuel and an oxygen-carrying gas and a radial thereon connecting drain. 18. Device according to claim 17, characterized in that an inner wall with passages is arranged approximately parallel to the outer wall to a central part of the room. 19. Device according to one or more of claims 1-18, characterized in that material is provided on the walls of the reaction chamber and / or the guide bodies which can act as a catalyst in the reforming of hydrocarbons. Apparatus according to one or more of claims 1-19, characterized in that porous bodies are arranged in or on the walls of the reaction chamber, wherein the porous bodies function as a support for one or more catalysts. Device according to one or more of claims 1-20, characterized in that one or more of the constituent parts of the reaction chamber are made of a material with a heat conductivity coefficient greater than 200 W / (m.K). 10 22. Device according to one or more of claims 1-20, characterized in that means are provided for introducing into the device an amount to be metered per unit time of a liquid or vapor phase medium. Device according to claim 22, characterized in that the medium is water. 1013325