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Title:
DEVICE FOR REFORMING HYDROCARBON-CONTAINING FUELS AND GASIFYING THEM
Document Type and Number:
WIPO Patent Application WO/2001/029393
Kind Code:
A1
Abstract:
The invention relates to a method and device for reforming hydrocarbons of a fuel, said device being provided with a fuel supply, a reaction chamber connected to the supply, an outlet of the reaction chamber to a combustion engine and heat exchanger means between the reaction chamber and a source of heat, said reaction chamber comprising one or a number of successive tube parts in which guiding means for generating a flow pattern have been mounted, or said reaction chamber comprising a number of successive tube parts extending in opposite directions, with abrupt transitions mounted between them.

Inventors:
HANNON MICHALE FRANCIS (US)
DOORN ROBERTUS JOHANNES (NL)
Application Number:
PCT/NL2000/000752
Publication Date:
April 26, 2001
Filing Date:
October 18, 2000
Export Citation:
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Assignee:
AIR PROPULSION INTERNAT N V (NL)
HANNON MICHALE FRANCIS (US)
DOORN ROBERTUS JOHANNES (NL)
International Classes:
F02M27/02; F02M29/06; F02M31/125; F02M31/18; F28D7/10; F28F13/06; (IPC1-7): F02M29/06; F02M27/02
Foreign References:
US3866585A1975-02-18
US1809438A1931-06-09
DE4213583A11992-10-29
US4478198A1984-10-23
DE19650362A11997-10-30
DE1086485B1960-08-04
US3828736A1974-08-13
Attorney, Agent or Firm:
Blauw, Frans G. (Haagsch Octrooibureau Breitnerlaan 146 HG The Hague, NL)
Download PDF:
Claims:
C L A I M S
1. Device for reforming hydrocarbons of a fuel, said device being provided with a fuel supply, a reaction chamber connected to said supply and being provided with one or more catalysts or not, an outlet from said reaction chamber to an internal combustion engine and heat exchanger means between the reaction chamber and a source of heat, characterized in that the reaction chamber comprises at least one chamber, means for generating a flow pattern in the fuel being provi ded on at least one location.
2. Device according to claim 1, characterized in that said means are designed such, that a vortex can be generated in the fuel.
3. Device according to claims 12, characterized in that the reaction chamber is incorporated in the fuel supply to the internal combustion engine preceding a mixing member at which the fuel can be mixed with an oxygencarrying gas.
4. Device according to claim 3, characterized in that the reaction chamber comprises at least two coaxial tube parts with at least one helical duct being provided between said tube parts.
5. Device according to claim 4, characterized in that a helical groove or rib is provided in one of the tubes.
6. Device according to claim 3, characterized in that the reaction chamber consists of a tube being received in a housing and being at least partly helical, in which the helical tube is part of a wall of an orifice for a heating medium, mounted in the housing.
7. Device according to claims 36, characterized in that the helical duct or tube contains one or more guiding members also having a helical shape.
8. Device according to claims 37, characterized in that an inlet and outlet connecting tangentially to the helical duct or tube have been provided.
9. Device according to claims 38, characterized in that a supply and discharge for a liquid or gaseous heating medium are connected to the coaxial tube assembly or the housing in such a way, that the medium can at least flow through the inner tube or centrally through the housing.
10. Device according to claims 12, characterized in that the reaction chamber is incorporated in the fuel supply to the internal combustion engine preceding a mixing member at which the fuel can be blended with an oxygencarrying gas.
11. Device according to claim 10, characterized in that the reaction chamber consists of one or a number of subse quent tube portions, or of two or more tube portions mounted in parallel, in which latter case means for opening or clos ing at least one of said tube portions are provided.
12. Device according to claim 10, characterized in that the means consist of valves opening at a predetermined underpressure or overpressure.
13. Device according to claims 1012, characterized in that a reaction chamber or its assembling chambers con tain one or more guiding members, the guiding member being substantially a helicoidal guiding member or consisting of a number of helicoidal guiding members mounted coaxially.
14. Device according to claim 13, characterized in that a region directly arounds the axis of the guiding member or guiding members offer a free passage across at least a part of the length of the guiding member (s).
15. Device according to claims 1314, characterized in that the guiding member or guiding members, seen in crosssection along the axis, have a curvature, the convex side being at the upstream side.
16. Device according to claims 1315, characterized in that the guiding member or guiding members, seen in a direction from a point of tangency of a guiding member, has/have a chamber wall inclining in downstream direction towards the axis.
17. Device according to one or more of the claims 13 16, characterized in that the radius of the helicoidal guiding member or members increases/increase in downstream direction.
18. Device according to one or more of the claims 13 17, characterized in that the outer circumference of the guiding member or members connect (s) to the reaction chamber wall.
19. Device according to claims 12, characterized in 1 that the reaction chamber comprises at least one duct having one or more square transitions.
20. Device according to claim 19, characterized in that a duct comprises a number of subsequent parts extending in opposite direction, with the ends of the parts of the duct, contrary to the ends of the duct, end into recesses provided in end plates.
21. Device according to claim 19, characterized in that the recesses have a substantially flat bottom which is approximately square to the ends of the duct ending in it.
22. Device according to claims 121, characterized in that the reaction chamber is at least partly incorporated in, or part of, an engine block or exhaust system.
23. Device according to claims 121, characterized in that the reaction chamber is provided with a photovoltaical controlled heating member.
24. Device according to claims 121, characterized in that at least one highfrequency oscillator member is provi ded such that at least a part of the reaction chamber is situated within its range of radiation.
25. Fuel injection system in which the fuel supply contains a reaction chamber according one or more of the preceding claims and further a fuel reservoir, a fuel pump and a pressure controller have been provided, characterized in that the fuel reservoir, the fuel supply pump and the pressure controller form a closed circuit in which a connec tion has been provided between fuel supply pump and pressure controller, which successively leads to the reaction chamber and one or more fuel injection members.
26. Fuel injection system in which a reaction chamber is incorporated in the fuel supply according to one or more of the preceding claims in which further a fuel reservoir, a fuel supply pump and an injection pump have been provided, characterized in that the fuel reservoir, fuel supply pump and injection pump form a closed circuit and that at least one reaction chamber is incorporated in the line or lines from the injection pump to one or more reaction chambers of an combustion engine.
27. Method of reforming a fuel and supplying a reformed fuel to an combustion engine, characterized in that it comprises at least the following steps: heating the fuel to at least a predetermined tempera ture, in which heating takes place before mixing the fuel with an oxygencarrying gas; mixing the reformed fuel with an oxygencarrying gas; supplying the mixture of the reformed fuel and oxy gencarrying gas to the combustion chamber (s).
28. Method according to claim 27, characterized in that the fuel is heated to such a temperature that at least part of the fuel passes into the gas phase.
Description:
Device for reforming hydrocarbon-containing fuels and gasi- fying them The invention relates to a device for reforming hydro- carbons of a fuel, said device being provided with a fuel supply, a reaction chamber connected to said supply and being provided with one or more catalysts or not, an outlet from said reaction chamber to an internal combustion engine and heat exchanger means between the reaction chamber and a source of heat.

Such a device is known from US-A-3,828,736. Said known device is intended for use with a fuel, e. g. gasoline, being free of additives, such as cyclic hydrocarbons and lead compounds, required for obtaining a high octane content.

Further, said device is complicated in the sense that a measured volume of exhaust gases must be added to an atomi- zed fuel/air mixture before the mixture can be supplied to the reaction chamber, and that before the reformed gas can be supplied to an internal combustion engine, a measured volume of air must be added to it.

The object of the invention is to provide a device that does not have said disadvantages, that has a relatively simple structure and that can be used with the most common types of fuel, available at gas stations, for automobiles, thus fuels with additives. A further object of the invention is to gasify at least a part of the fuel during reformation of the fuel, in order to achieve a further improvement of the combustion.

To that end, according to the invention it is provided for, that the reaction chamber comprises at least one cham- ber, means for generating a flow pattern in the fuel being provided on at least one location. Preferably, said means are designed such, that a vortex can be generated in the fuel.

Bringing the fuel or the mixture of fuel and oxygen- carrying gas into a vortex provides a number of advantages.

Firstly, the fuel or the mixture of fuel and oxygen-carrying gas follows a relatively long path in relation to the length of the chamber, in which the vortex creates a radial distri- bution of the various hydrocarbon molecules and particularly the larger, heavier hydrocarbon molecules to be reformed are forced against the reaction chamber wall by the centripetal force. This has the advantage, that the transfer of heat from the chamber wall to the hydrocarbon molecules also substantially occurs in the direction of exactly the larger hydrocarbon molecules.

A further advantage is the fact that by conveying the larger hydrocarbon molecules in a vortex along the reaction chamber wall, they can not only be reformed by a thermal process and, if provided, by the catalytic action of the reaction chamber wall, but also by mechanical action. Not only the friction of said larger hydrocarbon molecules along the wall contributes to the reformation of said molecules, but also the heat generated with it as a consequence of the vortex.

Of great importance is the cleaning action by friction which the fuel or fuel/air mixture brought in a vortex can exert on the reaction chamber wall (s). This provides for continuous removal of the deposit caused by the additives in the fuel, as a result of which the catalytic action of the reaction chamber wall or catalyst separately mounted on it, will not or only partly reduced.

According to a preferred embodiment, it is provided for that the reaction chamber is incorporated in the fuel supply to the internal combustion engine preceding a mixing member at which the fuel can be mixed with an oxygen-carrying gas.

This has the essential advantage that reformation of the fuel can be safely performed at a higher temperature than would be possible with a mixture of a fuel and an oxygen- carrying gas. This allows for a better division in shorter hydrocarbon chains and at least a part of the fuel can be

brought into the gaseous phase, depending completely or partly on the temperature.

According to a first embodiment, the reaction chamber comprises at least two coaxial tube parts with at least one helical duct being provided between said tube parts. Accor- ding to the invention, such a helical duct is realized by making a helical groove of rib in one of the tubes. This has the advantage, that the coaxial tubes can be located relati- vely close on top of one another and that they are in con- tact across such a large portion of the tube surface, that an appropriate transfer of heat between the tubes is possi- ble. Therefore, thermal reformation of the fuel only requi- res heating from one side, in which it makes no difference from which side it will be. Preferably, tube materials having an appropriate thermal conductivity are used.

According to a further embodiment, the reaction chamber consists of a tube being received in a housing and being at least partly helical, in which the helical tube is part of a wall of an orifice for a heating medium, mounted in the housing. This embodiment has the advantage that it can be manufactured relatively easily.

The helical duct or tube can additionally contain guiding members also having a helical shape, as a result of which a second helical flow pattern is superimposed on the first flow pattern.

For heating the reaction chamber, one can use e. g. the coolant of an internal combustion engine, or the oil of the lubricating system. A simple embodiment then consists of coaxial tubes in which the connections for supply and dis- charge of the fuel to and from the reaction chamber have been provided and in which the liquid medium used for hea- ting is led through the inner tube. However, it is also possible to work with e. g. three coaxial tubes, in which the liquid medium used for heating can flow along both sides of the reaction chamber. Then, the connections for the fuel to be reformed must be led through the outer tube liquid-tight.

In the embodiment having a helically extending tube in a solid housing, the tube partly forms an orifice for a heating medium, made in the housing. Then the housing provi- des for transfer of heat to the part of the housing which is not in direct contact with the medium.

Instead of using a liquid medium for heating, one can of course also work with a gaseous medium, such as the exhaust gases of the internal combustion engine.

According to a further elaboration, the reaction cham- ber can also be at least partly received in, or be part of, an engine block or exhaust system. For example, the reaction chamber could be completely or partly integrated in an engine block or manifold during their manufacture.

Instead of the embodiments described above, it is also possible to incorporate the reaction chamber in the fuel supply to the internal combustion engine, behind a mixing member where the fuel can be mixed with an oxygen-carrying gas. Although here, for safety reasons, the fuel/air mixture will be reformed at less high temperatures, it is still possible to achieve essential improvements in relation to the situation where there is no reformation.

Here, the embodiments described above can be applied, but also ones with tube portions to be mounted on or in an exhaust pipe or exhaust manifold. With a reaction chamber composed of such tube portions, it can consist of one or a number of subsequent tube portions, or of two or more tube portions mounted in parallel, in which latter case means for openingen or closing at least one of said tube portions are provided. The tube portions will then contain one or more guiding members, the guiding member being substantially a helicoidal guiding member or consisting of a number of helicoidal guiding members mounted coaxially.

The invention also provides for an embodiment of the reaction chamber in which the reformation of a fuel is established by a more mechanical action. To this end it is

provided for, that the reaction chamber comprises at least one elongated duct having one or more square transitions.

According to another elaboration, preferably it is provided for that a duct comprises a number of subsequent parts extending in opposite direction, with the ends of the parts of the duct, contrary to the ends of the duct, end into recesses provided in end plates. Here, the inlet and outlet for the fuel are provided at the same end plate or on opposite end plates.

Here, the underlying thought is that by passing the fuel through the duct (s) at high velocity, the impulse force and changes in velocity occuring when the fuel hits the end plates will cause the hydrocarbon chains to be at least partly divided into smaller chains. Heating is necessary and the use of catalytically acting materials and application of a helicoidal guiding member in the air inlet can provide a further improvement of the process.

Heating can take place by heating the parts of the duct enclosed between the end plates. According to a further elaboration, this can be achieved by mounting a tube around the reaction chamber, in which the end plates will close the tube at both sides and in which the tube or end plates are provided with an inlet and outlet for a liquid medium which is to provide heating. It goes for this reaction chamber too, that heating can take place with coolant or oil from the lubrication system of an internal combustion engine, and that the reaction chamber can be completely or partly inte- grated in the engine block.

Apart from said heating systems, in which the heat generated by an internal combustion engine is employed, it is also possible to use other energy sources for at least part of the heating. This may play a part in starting an internal combustion engine, in which one can't yet use heat generated by the engine. Possible energy sources are e. g. a heating spiral connected to the electric circuit, or a high frequency source of radiation such as a magnetron.

In countries having a sufficient amount of sun hours per day, one can also use solar energy in which one may think of a heating system fed with the help of photovoltaic cells, or a system in which a liquid heating medium is directly brought to temperature by the sun.

Further, the invention provides for injection systems for petrol and diesel engines, respectively, which will be further explained in the following, an important feature being that the fuel is reformed and is at least partly brought into the gaseous phase, contrary to the atomizing systems applied up to now, in which the fuel remains largely in liquid state, preceding the mixing of the fuel with an oxygen-carrying gas.

In the following, the invention is explained by way of the example given in the drawing, in which: Fig. 1 illustrates a reaction chamber composed of coaxial tube portions; Fig. 2 illustrates a reaction chamber consisting of a helically extending tube within a housing; Fig. 3 illustrates diagrammatically a reaction cham- ber mounted on an exhaust manifold; Fig. 4 illustrates diagrammatically an embodiment having tangentially connecting tube parts; Figs. 5A, B, C, D illustrate diagrammatically three embodiments of a guiding member; Fig. 6 illustrates diagrammatically a further embodi- ment for a guiding member; Fig. 7 illustrates diagrammatically a system having two reaction chambers; Fig. 8 illustrates diagrammatically an embodiment of a reaction chamber for passing a substantial liquid fuel; Fig. 9 illustrates the embodiment according to Fig. 8 which is provided with an expansion chamber; Fig. 10 illustrates diagrammatically a cross-section through a cylinder having a fuel injection system;

Fig. 11 illustrates a reaction chamber composed of subsequent tube parts extending in opposite directions; Fig. 12 illustrates a diagram of the fuel supply to a fuel injection device having a reaction chamber incorporated therein; Fig. 13 illustrates a diagram of the fuel supply to a fuel injection device having one reaction chamber per cylin- der; and Fig. 14 illustrates a diagram of the fuel supply with an internal combustion engine with carburettor.

The reaction chamber illustrated with cut-away parts in Fig. 1 is constituted of two coaxial tube parts 2,3, with a helical duct 4 being formed between them. In the example illustrated, the duct is formed by providing a helical groove 5 at the outside of the inner tube portion 2.

The reaction chamber 1 is provided with an inlet 6 and an outlet 7 for the fuel to be reformed, which have been mounted on the exterior of the outer tube 2. The positions of inlet 6 and outlet 7 are such that they connect tangenti- ally to the helical duct 4.

The outer diameter of the inner tube 3 is approximately equal to the inner diameter of the outer tube 2 due to which the tube parts will abut each other completely, except for the helical groove 5. At the outer ends, a further sealing can be provided e. g. by applying a weld along the boundary of the outer and inner tubes.

Further, the length of the inner tube 3 can be chosen larger than that of the outer tube 2, so that the inner tube 3 can project at both sides of the outer tube 2. These outer ends will then provide the possibility of mounting connecti- ons for tube or line portions for a liquid or gaseous medium intended for heating the reaction chamber. A heating element could be placed in it.

The reaction chamber 8 according to Fig. 2 comprises a housing 9 in which a helically extending tube 10 having an

inlet 11 and an outlet 12 is received. The tube 10 is of a highly heat-conducting material such as e. g. copper and the housing 9 of e. g. aluminium. With these materials, it is possible to mount the housing 9 across the copper tube 10 with the help of a casting process. Here, a part of the housing 9 and a part of the tube 10 form the wall of an orifice or flow duct 13. Tube parts 14,14', 15,15'have been mounted or cast at the outer ends of the housing for allowing lines for a heating medium to be connected to said reaction chamber. The offset provided in the tube parts 14, 14', 15,15'allows for connecting lines of various diame- ters.

Several tests have proven these reaction chambers to be particularly effective, in which there is the condition that one heats to a temperature of 80°C or higher.

Fig. 3 shows schematically an example of a reaction chamber mounted on a position in de supply to a combustion engine where the fuel has already been at least partly mixed with an oxygen-carrying gas. A combustion engine 16 having four cylinders 17,18,19,20, an inlet manifold 21 and an outlet manifold 22 and a further exhaust pipe 23 have been indicated in the figure. The reference number 24 indicates a mounting plate 24 for mounting a carburettor or another member for supplying the fuel/air mixture. From the mounting plate, a tube part 25 leads the mixture to the actual reac- tion chamber 26 and from there through a connecting tube part 27 to the inlet manifold 21 and subsequently to the cylinders 17,18,19,20.

In the given example of Fig. 3, the actual reaction chamber 26 is packed in a heat-resistant enclosure 25 in which a heat-conductive and transformable medium is located.

Such a heat-conductive medium can consist of e. g. a heat- conductive paste or aluminium or copper particles and/or plates. Instead of with a fuel supply having a carburettor, the device can also be applied with a fuel injection system, in which in this figure, a fuel pump should be connected to

the tube part 25 and the tube part 27 would connect to the actual injection system. Since then, substantially a liquid fuel should be directed through the reaction chamber, the diameter of successive tube parts is chosen smaller than for a fuel/air mixture, in order to be able to maintain a suffi- cient rate of flow through the device (see also Figs. 8,9).

Fig. 4 illustrates an example with tube parts 29,30, 31,32 tangentially connecting to one another, tube part 29 being connected to the mounting plate 24 for the carburettor or a similar member and tube part 34 being connected to a fixing flange for connection with the inlet manifold not further illustrated.

The tube parts are always offset in relation to one another, the upstream tube part always connecting tangent- ially to the next tube part, with a curvature or, like here, a flat adjustment 36 being provided. By this transition tangentially connecting to the next tube part, the fuel or the fuel/air mixture is brought into a vortex again and again. The transition between the tube portions 33,34 is exactly opposite to the preceding transitions in order to prevent the mixture from entering the inlet manifold in a vortex and thereby possibly causing a uneven distribution of the mixture in the cylinders.

Further, an inlet 65 is mounted on the tube part 33, through which additional air can be supplied to the reformed mixture. Said inlet 65 also connects tangentially to the tube portion 33 and in the direction of the vortex generated there, as a consequence of which a better blending with the mixture can be achieved. The inlet can further be provided with an underpressure-dependent valve.

The effect of the air supplied in this way is particu- larly well noticeable with the higher speeds at which the engine can operate, e. g. with driving on the highway, in which the underpressure of the engine is the highest. In this way, more power and a more economic consumption is realized at the same initial amount of fuel/air mixture.

The inlet 65 is also suitable for e. g. supplying a certain amount of water or water vapour or hydrogen to the mixture.

In this embodiment, the tube part 31 will be mounted on the outlet manifold, but preferably, the tube parts 31,32 and also portions of the tube parts 30 and 33, are thermally coupled to the outlet manifold by a highly heat-conductive enclosure. Then, the actual reaction chamber will extend across a major part of the total length of the tube parts.

With the most common construction materials, the tube parts will already have some catalytic effect on reformation of the larger hydrocarbon molecules. However, it is just as well possible to apply a specifically catalytic material in the inner surface of the tube walls.

Four guiding members 27,28 to be brought into a tube part are shown in Figs. 5 A, B, C, D. The guiding member 27 is helically wound and has, in relation to the tube part in which it should be mounted, a diameter such that the outer circumference will contact the inner side of the tube porti- on 30, in order to have a proper thermal contact with it.

The guiding surface 31 of the guiding member extends radially from the outer circumference 39 up to some distance from the centre line 42, so that a free continuous space remains around the centre line 42. The guiding surface is curved in radial direction and in such a way that at the upstream side, arrow 43 indicates the direction of flow, the guiding surface is convex. Owing to this, the lighter hydro- carbon molecules arising during reformation, can get quicker into the central onderpressure part of the guide 37,38 and into the tube 40 and from there continue directly to inlet manifold and combustion engine.

Fig. 5C shows a similar guiding body 38, its guiding surface, seen radially in cross-section, being straight with a slope towards the centre line 45 which always goes with the stream.

Fig. 5D shows a similar guiding body 67, its diameter tapering with those of the subsequent tube parts 65,66. The tube parts and the guiding body are intended for providing a volume enhancement for an expanding fuel or a fuel/air mixture as a consequence of its warming-up.

Fig. 6 shows a tube part 46 with a number of coaxial guiding members 47,48,49,50,51, together in turn provi- ding a free central passage 52. Such an embodiment has the advantage of a much larger surface and due to that a better heat transfer and catalytic action.

Fig. 7 shows an embodiment of the device having a tube part 25'coming from a carburettor or similar member, a reaction chamber comprising tube parts 53,54 with respecti- ve guiding bodies 55,56, and a further tube part 27'con- necting to tube portions 53,54, through which the fuel/air mixture can be supplied to the combustion engine through said inlet manifold.

Tube parts 53,54 are mounted in parallel, in which one of the tube parts can be closed-off with the help of valves 47,48 mounted at one end or both ends. The valves are designed or switched in such a way that in case of a greater demand and thereby a greater underpressure, the valves will open and the required fuel/air mixture can be led through both tube parts 53,54. With a smaller demand, the pressure drop across both tube parts 53,54 will not be sufficiently large to be able to generate the desired vortex, so that then one tube part can suffice.

The most simple embodiment of the valves is a pressure- dependent mechanichal valve, which doesn't require any external operation. Such a valve 58 has e. g. a valve seat 66 onto which flexible valve portions 67,68,69 have been fastened with fasteners 70,71,72. The valve portions 67, 68,69, which are made of sheet metal, for example, will be opened at a sufficiently large underpressure, the valve portions forming a tangential transition with the connecting tube part. Additionally, the valve can be provided with an

electromagnet 73 by which the valve portions can be closed and kept closed at an otherwise sufficient underpressure as well.

Fig. 8 illustrates an embodiment of a reaction chamber substantially consisting of a continuous tube 74 having a relatively small diameter, the outer ends being provided with connecting flanges 75,76 for connection to a fuel pump and the entrance of a fuel injection system, respectively. A guiding body 77 is mounted within the continuous tube 74 across a major part of its length, or all of its length. In the example concerned, the guiding body consists of two twisted threads 78,79, which are inserted into the tube part 74 before the tube portion is bent into the desired shape. With the use of both copper tube 74 and copper thre- ads 78,79, a reaction chamber is obtained which is easily deformed and thus can be simply mounted on an exhaust mani- fold, or be made suitable for use in combination with anot- her source of heat in a simple way.

The embodiment according to Fig. 9 differs in relation to the previous embodiment in that an expansion chamber 80 has been provided, in order to be able to accomodate volume changes caused by heating of the fuel. Such a provision will not always be necessary, this depends on the temperatures achieved with the source of heat employed, among other things.

The cross-section according to Fig. 10 shows a cylin- der/piston assembly 81,82 having an inlet 83 with accompa- nying inlet valve 84 and an outlet 85 with accompanying outlet valve 86. The inlet 83 is further provided with an adjustable air valve 87 and an injection valve 88. Through line 89, the inlet valve 88 is connected with the supply of the fuel reformed in the reaction chamber.

The rising temperature in the reaction chamber causes the fuel to pass partly or completely into the gas phase, bringing the mixture under a higher pressure than the pres- sure at which the fuel was initially brought into the reac-

tion chamber. When this mixture arrives at a fuel injection member from said reaction chamber, said fuel injection member being mounted within an air inlet duct for a cylinder of a combustion engine in such a way that it points in the direction of the inlet valve of that cylinder, the high- pressure mixture emerges from the injection member at high velocity and immediately expands, filling a large portion of the inlet duct, and travels at high velocity in the directi- on of the combustion chamber 90. This rapidly advancing volume of heated and expanded fuel mixture forces the volume of air located in front of it into the combustion chamber 90, at the same time air behind it is taken along into said combustion chamber 90 as a result of molecular cohesion and pressure differential eliminating forces. This reduces the load on the piston to bring the fuel/air mixture into the combustion chamber 90 and with it, the absorbed amount of energy supplied by the engine, as a consequence of which the final amount of energy to be produced per cylinder/piston assembly will increase.

Such an effect is comparable to the effect of a"super- charger"or a"turbocharger", which are both applied to force air into an inlet duct. However, the big difference is that such devices are driven by the engine and represent a load for the engine, while the energy required for reforming the fuel is nothing more than energy which otherwise would have been lost. Thus, the source for the"charging"effect of the process indicated above can be traced back entirely to the heated and reformed fuel itself. By mounting the injection member on an appropriate location within the air duct, e. g. at 91, and positioning it such, or providing for further means, that a vortex will be generated there too, the effect of the process described can be further enhanced.

Tests have shown that an automobile having an engine with a computer-driven"multipoint"fuel injection system in which the device according to the invention is incorporated, has a high power across the entire speed range, reaches a

considerably higher top speed, at the same time achieving a much more economic consumption than with the standard versi- on of the engine, also for fuels having low octane contents, and that furthermore importantly lower emission rates are achieved both in quality and quantity.

Comparable results can be obtained with gaseous fuels such as propane gas, when they are led through a reaction chamber before being supplied to injection members in compa- rable"multi point"injection systems. A similar effect can be achieved with"single point"injection systems.

Further, with this fuel injection system, a water or hydrogen injection system having a schematically indicated injection member 91 can additionally be provided for. There, the operating signal for opening and closing the injection member 91 can be directly depending on a corresponding signal for the injection member 88, in which said member should be adjusted to the desired amount of water or hydro- gen. It is also possible to inject fuel and water or hydro- gen at the same time by one and the same injection member.

Then, the amounts of water or hydrogen and fuel are supplied to the injection member through two separate lines.

The reaction chamber 98 according to Fig. 11 comprises a duct 100 formed by a number of subsequent tube parts 99, being held and kept spaced apart by three plates 101,102, 103. The ends of two subsequent tube parts end in recesses 106 provided in the end plates 104,105. The recesses 106 provide for a contact plane against which the fuel can impinge with high impulse force, as well as for sudden velocity transitions in the flow.

With the help of the threaded ends 107,108 and nuts 109, the plates 101,103 are clamped against the end plates 104 and 105, respectively, by which the whole forms one duct 100. Inlet 110 and outlet 111 for the fuel to be reformed have been mounted on the end plate 104. However, it is also possible to mount inlet and outlet 110,111 separately on an end plate 104,105.

The reaction chamber 98 can be inserted entirely in a tube part not further indicated, through which a liquid or gaseous medium, which is intended to provide for heating the reaction chamber, can be led. The end plates 104,105 can serve for sealing said tube portion.

Fig. 12 provides a diagram for a fuel supply to a fuel injection device 112 having injection members 119 in which a reaction chamber 113 is incorporated. From the fuel reser- voir 114, a fuel line 115 extends through a supply pump 116, a fuel filter 117 and a pressure regulator 118 back to said fuel reservoir 114. Between fuel filter 117 and pressure regulator 118 extends a branch which leads subsequently to the reaction chamber 113 and the fuel injection device 112.

The pressure in the reaction chamber 113 and fuel injection device 112, respectively, is controlled with a pressure regulator 118 set to a fixed value, the pump pressure sup- plied by the supply pump 116 being higher than the set value of the pressure regulator 118.

With the usual injection systems, the fuel injection device is incorporated in the loop of the fuel line 115, the pressure regulator being mounted directly downstream of the fuel injection device. When applying a reaction chamber as described, not using fuel already reformed and leading it back to the fuel reservoir again is not very effective.

Further, in the reaction chamber the fuel passes into the gas phase at least partly, which can also cause problems if partly gaseous fuel portions would be returned to the fuel reservoir 114 through the return part of the fuel line 115.

Fig. 13 illustrates a diagram for an injection device 122 having injection members 123 intended especially for a diesel engine. The important difference with fuel injection systems for petrol is that a significantly higher injection pressure is employed, to which end a separate injection pump is provided. From a reservoir 124 for diesel fuel, the diesel is led through line 125, supply pump 126 and filter 127 to an injection pump 128. The surplus supplied amount

diesel fuel is directed back to the fuel reservoir 124 through the return line 129.

From the injection pump 128, a separate line 130 ex- tends to each cylinder, a reaction chamber being incorpora- ted in each line 130. With this embodiment, the reaction chamber is designed differently in such a way that it can resist a much higher injection pressure than is employed with petrol injection.

Finally, fig. 14 provides a diagram in which the reac- tion chamber 132 is incorporated in the fuel supply line 133 to a carburettor 134. Again, from a fuel reservoir 135, with a supply pump 136 the fuel is supplied to the reaction chamber 132, through the line 133 and filter 137. The dash line 138 indicates a return line for the surplus of supplied fuel, the retour line again being mounted in front of the reaction chamber in such a way, that only fuel not yet reformed can be returned. The return line is indicated with a dash line since not every fuel system with carburettor requires a retour line.

Basically, it is also possible to incorporate the reaction chamber 132 after the carburettor 134. However, then a mixture of fuel/air will be reformed which will prove less effective. Additionally, on account of the risk of ignition, one has to work with a lower temperature which reduces the result even further.

-claims-