WO2007036213A1

WO2007036213A1 - Combustion engine and injection device

Info

Publication number: WO2007036213A1
Application number: PCT/DE2006/001699
Authority: WO
Inventors: Jörg ARNOLD
Original assignee: Ip2H Ag
Priority date: 2005-09-27
Filing date: 2006-09-26
Publication date: 2007-04-05

Abstract

Disclosed is a combustion engine comprising an injection device (1) for injecting a combustible fuel into a combustion chamber (2). In order to burn the fuel in an optimized manner to reduce consumption, said combustion engine is embodied and further developed in such a way that the injection device (1) is provided with a means (3) for evaporating the fuel before the fuel is burned. Also disclosed is an injection device (1) to be used in such a combustion engine.

Description

COMBUSTION ENGINE AND INJECTION DEVICE

The invention relates to an internal combustion engine having an injection device for injecting a combustible fuel into a combustion chamber. Furthermore, the invention relates to an injection device for use in such an internal combustion engine.

Internal combustion engines and injection devices of the type mentioned are known in practice and exist in a variety of embodiments. The known engines are operated with any fuels such as gasoline or diesel or alternative fuels. The known engines and injectors find their application, for example in the automotive field.

In modern internal combustion engines, the supply of the combustible fuel into the combustion chamber by means of an injection device, which provides a precisely predetermined amount of fuel at the appropriate time. The timing and amount of injected fuel can be adjusted to the requirements of optimized combustion and detoxification of the exhaust gas. In this case, a droplet stream is usually injected into the combustion chamber.

With regard to combustion engines that are as fuel-efficient as possible, it is desirable to generate a fuel gas mixture which is as much as possible emaciated for ignition in the combustion chamber or to inject as little fuel into the combustion chamber as possible at a required power output. Despite the most optimized injection fuel consumption is still relatively high in the known internal combustion engines.

The present invention is therefore based on the object of specifying an internal combustion engine and an injection device of the aforementioned type, according to which the combustion of the fuel is further optimized with a view to a reduction in consumption with structurally simple means. 99

According to the invention the above object is achieved by an internal combustion engine with the features of claim 1. Thereafter, the internal combustion engine is configured such that the injector has means for evaporating the fuel prior to its combustion.

In accordance with the invention, it has first been recognized that the above object is achieved in a surprisingly simple manner by a clever design of the injection device. For this purpose, the injector in concrete in a further inventive manner, a means for evaporation of the fuel prior to its combustion. By the evaporation of the fuel before its combustion or by a supply of the fuel to its place of combustion in vaporized form, an ignitable fuel gas mixture in the combustion chamber is particularly fast. This improves the combustion process in terms of fuel consumption. The evaporation process of the fuel is thereby displaced before the ignition phase to bring the fuel gas mixture quickly into an ignitable state.

Specifically, the means could comprise a heatable capillary through which the fuel is passed for evaporation. This represents a structurally particularly simple way of evaporating the fuel before it is combusted. In this case, the fuel could be guided by an injection pump via the heatable capillary into the combustion chamber.

In a structurally particularly simple manner, the capillary could be electrically heated. The fuel is vaporized in the hot capillary.

With regard to a particularly simple heating of the capillary, a heating wire could be arranged in the capillary. Such a heating wire could be heated by an electrical current flowing therethrough, which would then result in heating of the capillary.

With regard to a particularly safe heating of the entire capillary, the heating wire could preferably extend through the entire capillary. T / DE2006 / 001699

In principle, the heating wire would have to be formed from a material which conducts the electric current and which heats up during the current flow. For this purpose, the heating wire could be designed in a structurally particularly simple manner of metal. Tantalum or tungsten are suitable as metals which are particularly preferred and mechanically stable in the case of heat, so that the heating wire could be formed from tantalum or tungsten.

To provide a particularly lightweight and yet dimensionally stable capillary, the capillary could be formed of a ceramic, wherein the capillary could preferably be designed as a ceramic tube.

With regard to a particularly simple heating of the capillary, the capillary could be formed at least partially or partially from metal. Due to the high thermal conductivity of metal, a simple heating is possible here.

The inner very hot capillary surface is usually exposed to the fuel flow. When the fuel stream in the capillary is substantially free of oxygen, the fuel hydrocarbons can react with the inner capillary surface to form an extremely temperature-resistant and chemically extremely corrosion-resistant passivation layer. For this purpose, the capillary could be formed at least partially or partially from a metal suitable for forming a metal carbide. Such a metal may in this case react with the hydrocarbon fuels to form a metal carbide. In a particularly advantageous manner, the capillary could be at least partially or partially made of tantalum in this regard. This metal is particularly suitable because of its chemical inertness.

The capillary could be at least partially formed as a conductor or web for their electrical heating. The use of metallic capillary components is particularly well suited. Such metal capillaries can themselves serve as a current path for the electric heating current. T / DE2006 / 001699

In a specific embodiment, the capillary could be arranged within the combustion chamber. The capillary could be heated in a particularly simple and energetically favorable manner directly from the hot combustion gases.

In an alternative embodiment, the capillary could be arranged outside the combustion chamber. In this case, the capillary is more accessible for maintenance purposes than in an arrangement within the combustion chamber.

In a particularly advantageous manner, the capillary could be partially disposed within and partially outside the combustion chamber. This makes it possible to combine the respective advantages of the arrangement inside and outside the combustion chamber.

The capillary length, the capillary passage and the capillary wall thickness must be adjusted so that the amount of fuel passed or pumped through each combustion cycle can absorb the necessary heat of vaporization in order to evaporate already in the capillary. A capillary that has cooled down in this way must be "recharged" with heat, for example, electrical heat or heat of combustion, until the next combustion cycle, to avoid heat losses that would have to be reintroduced to the capillary to ensure safe evaporation of the fuel For reasons of safety, electrical insulation is also advantageous.

In order to avoid heat losses particularly favorable manner, at least the arranged outside of the combustion chamber part of the capillary could be arranged in a heat energy storage. In other words, the capillary part, which is arranged outside the combustion chamber, could be packed in a corresponding energy store, which could also assume the task of electrical and / or thermal insulation to the outside. Ultimately, by avoiding heat loss, the energy consumption of the internal combustion engine is favorably influenced. 2006/001699

To ensure safe evaporation of the fuel, the temperature of the capillary before injection could be 800 ^° C. or more. The capillary could be safely embedded in a ceramic.

With regard to a particularly reliable supply of the vaporized or gasified fuel into the combustion chamber, the means could comprise a container for the fuel, in which the fuel is vaporizable or gasifiable. In this case, the container could be dimensioned so large that in all operating conditions of the internal combustion engine, a sufficient amount of vaporized or gasified fuel is available. In this case, the internal combustion engine could have both a system of capillary and upstream container and a system exclusively with the container and without the capillary. The supply of fuel into the combustion chamber could then take place exclusively from the container.

To ensure a high filling capacity of the container, the container could be a high-pressure container for pressures in the range of preferably 100 to 150 bar. This can usually provide a sufficient amount of fuel in the gasified or vaporized state for safe operation of the engine.

With regard to safe evaporation or gasification of the fuel in the container, a heating device could be associated with the container. Such a heater could be located both in the container and outside the container. In an arrangement of the heater in the container a particularly secure heat transfer to the fuel is possible.

For particularly reliable feeding of the gasified or vaporized fuel into the combustion chamber, the container could be assigned a distribution system for the vaporized or gasified fuel for supplying the vaporized or gasified fuel to the capillary or into the combustion chamber. Here, a supply from the container via a distribution system to the capillary and then into the combustion chamber or a system for supplying the fuel directly into the combustion chamber without intermediate capillary conceivable. The capillary ensures a particularly safe evaporation or gasification of the fuel, Design without capillary a simple construction of the internal combustion engine is realized.

In any case, in one embodiment of the internal combustion engine with a container, a rapid supply of the fuel to the combustion chamber is ensured. Supply shortages are thereby avoided. With the above container, continuous gasification or vaporization and provision of gasified or vaporized fuel is possible.

In order to achieve a sufficiently ignitable and optionally stoichiometric fuel concentration in spite of an overall greatly reduced mixture ratio in a local area of the combustion chamber, the fuel could be spatially inhomogeneous injectable. The fuel at the time of ignition could concentrate in a certain local area as, for example, a spatially limited steam jet or as a vapor cloud.

Since the gas displacement effect of the vapor is substantially greater than for a droplet stream and the droplets have a high "impact force" or strong penetration of the air original, it is much easier with fuel vapor to build up a concentration gradient Concentration gradients at the ignition point and can therefore be called "gradient technology". The term "stratified charge" would be too simple for this purpose.The steam injection is supported by the high degree of compaction and the high compression temperature and by the hot combustion chamber walls of a high-temperature concept for the internal combustion engine in order to avoid steam condensation.

With regard to a further optimized combustion of the fuel, at least one means for swirling the injected fuel could be arranged in the combustion chamber. This would allow a necessary enrichment of the fuel jet with atmospheric oxygen to achieve the ignitability by the already hot, injecting fuel vapor jet is guided in the combustion chamber via one or possibly more vertebral bodies in the combustion chamber. In a structurally particularly simple manner, the means could be designed as a preferably profiled pin.

With regard to the most reliable possible turbulence of the fuel vapor jet, the thickness of the pin could correspond approximately to the diameter of the cross-sectional area of the fuel vapor jet.

Concretely, for example, profiled pins could be provided, over the transverse profiles of the steam jet is guided. The subsequent generated turbulence with the air is carried out according to the vortex generation principle in aircraft wings, wherein the profile radius or the profile curvature of the pins determine the degree of turbulence or the air enrichment.

In a structurally particularly simple manner, the means or could be formed of metal pin. Here, tantalum is particularly favorable because it has a very high chemical corrosion resistance and mechanical material strength at very high temperatures.

To ensure a particularly effective turbulence of the injected fuel, the means could have a plurality of parallel aligned pins. Such pins could protrude, for example as bristles aligned in parallel brush-like manner from the combustion chamber surface and fill the free combustion chamber above the piston surface. Specifically, the pins could protrude from an interior surface of the combustion chamber or protrude from that surface. Alternatively or in addition thereto, the pins could substantially fill the combustion chamber via a piston arranged in the combustion chamber-with a distance from one another. The fuel vapor trail could then be directed perpendicular to the bristles or pins into the combustion chamber.

In a further advantageous manner, the pins could be formed as preferably heatable glow plugs. In this case, the compressed air could be further heated quickly to immediately reach the ignitability of the fuel-air mixture. Due to the small dimension of the pins or swirl pins this process could be called "micro-gasification" in the combustion chamber. Alternatively to the use of swirl pins, the means for swirling the injected fuel could also be formed as a wire mesh, wire tangle or wire wool. Such a wire mesh, wire tangle or such a wire wool could be advantageously formed of tantalum for Dampfverwirbelung and air heating.

For the above-defined "micro-gasification" the presentation of an enormous surplus of Oxidationsmittei is favorable, if not absolutely necessary, since the amount of fuel vapor for ignition in a very small volume with the necessary amount of oxidant must be supplied Mixture concentration to produce exactly at the ignition source is achieved by a high compression temperature, which allows the use of auto-ignition.The flammable fuel gas mixture does not have to be generated exactly at the ignition source, but the fuel gas mixture develops somewhere in the injection space monolocal its ignitability and ignites spontaneously.

In order for the "micro gasification" to provide reproducible results, the combustion chamber should be kept as free from air turbulence as possible, which is an essential difference to the diesel engine combustion technique the conceptual design of the described in DE 101 07096 A1 Schleppbüchsenmotors because he has an optimally symmetrical displacement or combustion chamber without whirling or pinching edges and the air through the control slots much less vortex happens than conventional poppet valves.

The rapidly increasing combustion temperature or the temperature increase in the residual gas, which emanates from the ignition, then leads to the reduction of the ignition limit of the residual fuel and to a subsequent complete combustion. It is ruled out, for example, that a fuel jet or a fuel cloud develops in such a way that he or she loses it again after passing through the local and temporary ignitability and regains it elsewhere. The ignition You can only assume one local area at a time. A combined process of high compression, lean mixture, pre-evaporation, gradient injection and micro gasification in the combustion chamber avoids multiple ignition and thus knocking of the engine, even at maximum base compression pressures or compression temperatures.

The required injection technology is already well developed and can be taken over from diesel engine injection technology. A possible combustion with strong combustion pressure peaks due to the strong excess of oxygen or oxidant is conceptually counteracted by a uniform injection over a certain controllable period of time. In this regard, the injector could be designed for pulsed injection. Alternatively, the injector could be configured for continuous injection. The injection can thus be carried out in a controlled manner from pulsed to continuous. The combustion may then be run, if appropriate, rather than a constant pressure combustion instead of a constant combustion. Due to the large excess of oxidizing agent or atmospheric oxygen in each operating state, the power control of the towed motor can be effected exclusively via the fuel quantity injection.

The high temperature tow motor can be operated against any diesel engine due to the proposed injection technique with any fuel. The combustion speed and ignitability of the fuels only play a minor role. The use of fuel and the development of fuel now no longer have to be based on the tendency to knock, but can concentrate entirely on optimizing the reaction side or the exhaust emission behavior of the fuels in the high-temperature combustion.

On closer inspection, it should be appreciated that the currently achievable efficiency of conventional reciprocating internal combustion engines is actually dictated and limited by fuel. The ignitability, the flame speed and the tendency to knock the fuel in conventional engine designs today give the maximum base compression of the engine and thus the possible Working temperature spread and thus the achievable thermodynamic efficiency before. The new ignition system concept according to the invention makes the engine design largely independent of the type of fuel used and thus allows a substantial increase in the thermodynamic efficiency in the first place.

The above object is further achieved according to the invention by an injection device according to one of claims 1 to 36. Reference is made to the preceding part of the description with regard to this injection device claimed in isolation and its advantages for avoiding repetitions, in the context of which the injection device is described in detail in its different embodiments.

There are now various possibilities for designing and developing the teaching of the present invention in an advantageous manner. For this purpose, on the one hand to refer to the subordinate claims, on the other hand to the following explanation of preferred embodiments of the internal combustion engine according to the invention with reference to the drawing. In conjunction with the explanation of the preferred embodiments with reference to the drawings, generally preferred embodiments and developments of the teaching are explained. In the drawing show

Fig. 1 to 3 in schematic representations parts of the Ausführungsbeispieie an internal combustion engine according to the invention.

1 shows, in a schematic side view, the part of an exemplary embodiment of the internal combustion engine according to the invention relating to an injection device 1. Specifically, the internal combustion engine has an injection device 1 for injecting a combustible fuel into a combustion chamber 2. With a view to optimizing the combustion of the fuel, the injector 1 comprises a means 3 for evaporating the fuel prior to its combustion. The fuel is thus evaporated before its combustion by the means 3 and passed in this vaporized form to the ignition in the combustion chamber 2. The means 3 has a heatable capillary 4 for the passage of the fuel. The capillary 4 is electrically heated and partially formed of metal. Specifically, the capillary 4 is partially formed of a metal suitable for forming a metal carbide, more specifically tantalum.

The capillary 4 is partially disposed within and partially outside of the combustion chamber 2. The arranged outside the combustion chamber 2 part of the capillary 4 is disposed in a heat energy storage 5, which provides not only a thermal and electrical insulation to the outside of the capillary 4 out.

In the combustion chamber 2, a means 6 for swirling the injected fuel is further arranged. As a result, the fuel is vortexed with a suitable amount of air prior to its combustion. The means 6 for swirling is designed as at least one profiled pin 7. More precisely, a plurality of pins 7 are arranged above a piston arranged in the combustion chamber 2 and not shown here - at a distance from one another.

The pins 7 are aligned parallel to one another and substantially fill the combustion chamber 2 above the piston.

The supply of the fuel via an injection pump 8 and a fuel line 9 to the capillary 4 and then into the combustion chamber 2. The injector 1 is designed for pulse-like injection. However, it is also conceivable to design the injection device 1 for continuous injection.

Figures 2 and 3 show further parts of embodiments of an internal combustion engine according to the invention, wherein in both embodiments, a container 10 is provided for the fuel in which the fuel is vaporizable or gasifiable. The container 10 is associated with a heater 11. Furthermore, in FIG. 3 the container 10 is assigned a distribution system 8 for the vaporized or gasified fuel for supplying the vaporized or gasified fuel to the capillary 4 and then into the combustion chamber 2. In the embodiment shown in FIG. 2, the vaporized or gasified fuel is passed directly from the container 10 via a fuel line 9 into the combustion chamber 2. The exemplary embodiments shown in FIGS. 2 and 3 can likewise have a means 6 for swirling the injected fuel with pins 7, as shown in FIG.

With regard to further advantageous embodiments and developments of the internal combustion engine according to the invention and the injection device according to the invention, reference is made to avoid repetition to the general part of the specification and to the appended claims.

Finally, it should be expressly understood that the above-described embodiments of the internal combustion engine according to the invention are only for the purpose of discussion of the claimed teaching, but do not limit these to these embodiments.

Claims

Patent claims

An internal combustion engine having an injection device (1) for injecting a combustible fuel into a combustion chamber (2), characterized in that the injection device (1) comprises means (3) for evaporating the fuel prior to its combustion.

2. Internal combustion engine according to claim 1, characterized in that the means (3) has a heatable capillary (4) for the passage of the fuel.

3. Internal combustion engine according to claim 2, characterized in that the capillary (4) is electrically heated.

4. Internal combustion engine according to claim 2 or 3, characterized in that in the capillary (4) a heating wire is arranged.

5. Internal combustion engine according to claim 4, characterized in that the heating wire extends through the capillary (4) therethrough.

6. Internal combustion engine according to claim 4 or 5, characterized in that the heating wire is formed of metal.

7. Internal combustion engine according to one of claims 4 to 6, characterized in that the heating wire is formed of tantalum or tungsten.

8. Internal combustion engine according to one of claims 2 to 7, characterized in that the capillary (4) made of a ceramic, preferably as a ceramic tube, is formed.

9. Internal combustion engine according to one of claims 2 to 8, characterized in that the capillary (4) is at least partially or partially formed of metal.

10. Internal combustion engine according to one of claims 2 to 9, characterized in that the capillary (4) is formed at least partially or partially from a suitable metal to form a metal carbide.

11. Internal combustion engine according to one of claims 2 to 10, characterized in that the capillary (4) is at least partially or partially formed of tantalum.

12. Internal combustion engine according to one of claims 2 to 11, characterized in that the capillary (4) is at least partially formed as a conductor or web for their electrical heating current.

13. Internal combustion engine according to one of claims 2 to 12, characterized in that the capillary (4) within the combustion chamber (2) is arranged.

14. Internal combustion engine according to one of claims 2 to 12, characterized in that the capillary (4) outside of the combustion chamber (2) is arranged.

15. Combustion engine according to one of claims 2 to 12, characterized in that the capillary (4) is partially disposed within and partially outside the combustion chamber (2).

16. Internal combustion engine according to claim 14 or 15, characterized in that at least the outside of the combustion chamber (2) arranged part of the capillary (4) is thermally and / or electrically isolated.

17. Internal combustion engine according to one of claims 14 to 16, characterized in that at least the outside of the combustion chamber (2) arranged part of the capillary (4) in a heat energy storage (5) is arranged.

18. Internal combustion engine according to any one of claims 2 to 17, characterized in that the temperature of the capillary (4) before injection is 800 ° C or more.

19. Internal combustion engine according to one of claims 2 to 18, characterized in that the capillary (4) is embedded in a ceramic.

20. Internal combustion engine according to one of claims 1 to 19, characterized in that the means (3) comprises a container (10) for the fuel, in which the fuel is vaporizable or gasifiable.

21. Internal combustion engine according to claim 20, characterized in that the container (10) is a high-pressure container for pressures in the range of preferably 100-150 bar.

22. Internal combustion engine according to claim 20 or 21, characterized in that the container (10) is associated with a heating device (11).

23. Internal combustion engine according to one of claims 20 to 22, characterized in that the container (10) has a distribution system (8) for the vaporized or gasified fuel for supplying the vaporized or gasified fuel to the capillary (4) or into the combustion chamber (2). assigned.

24. Internal combustion engine according to one of claims 1 to 23, characterized in that the fuel is spatially inhomogeneous injection.

25. Internal combustion engine according to one of claims 1 to 24, characterized in that in the combustion chamber (2) at least one means (6) for Verwir- beleagent of the injected fuel is arranged.

26. Internal combustion engine according to claim 25, characterized in that the means (6) is designed as a preferably profiled pin (7).

27. Internal combustion engine according to claim 26, characterized in that the thickness of the pin (7) corresponds approximately to the diameter of the cross-sectional area of the fuel vapor jet. 6 001699

28. Internal combustion engine according to one of claims 25 to 27, characterized in that the means (6) is formed of metal.

29. Internal combustion engine according to one of claims 25 to 28, characterized in that the means (6) is formed of tantalum.

30. Internal combustion engine according to any one of claims 25 to 29, characterized in that the means (6) comprises a plurality of parallel aligned pins (2).

31. Internal combustion engine according to any one of claims 26 to 30, characterized in that the pins (7) protrude from an inner surface of the combustion chamber (2) or protrude from this surface.

32. Internal combustion engine according to any one of claims 26 to 31, characterized in that the pins (7) the combustion chamber (2) via a in the combustion chamber (2) arranged piston - at a distance - substantially fill.

33. Internal combustion engine according to one of claims 26 to 32, characterized in that the pins (7) are designed as preferably heatable glow plugs.

34. Internal combustion engine according to one of claims 25 to 33, characterized in that the means (6) is designed as a wire mesh, wire tangle or wire wool.

35. Internal combustion engine according to one of claims 1 to 34, characterized in that the injection device (1) is designed for pulse-like injection.

36. Internal combustion engine according to one of claims 1 to 35, characterized in that the injection device (1) is designed for continuous injection.

37. Injection device (1) according to one of claims 1 to 36.