WO2010020221A2

WO2010020221A2 - Method for operating an internal combustion engine and fuel supply device for carrying out said method

Info

Publication number: WO2010020221A2
Application number: PCT/DE2009/001147
Authority: WO
Inventors: Agata Godula-Jopek; Christian Wolf; Helmut Oberpriller; Parth Gupta; Walter Jehle
Original assignee: Eads Deutschland Gmbh
Priority date: 2008-08-18
Filing date: 2009-08-08
Publication date: 2010-02-25
Also published as: DE102008038177A1; WO2010020221A3

Abstract

The invention relates to a method for operating an internal combustion engine (20) with fuel (34) made from hydrocarbons. According to the invention, a reduction in emissions and an increase in output with concomitant consumption optimisation may be achieved, whereby a partial dehydrogenation of the fuel (34) and introduction of the partially dehydrogenated duel together with the hydrogen (38) into the internal combustion engine (20) is carried out. A fuel supply device (10) for carrying out the method is also disclosed.

Description

Method for operating an internal combustion engine and fuel supply device for carrying out the method

The invention relates to a method for operating an internal combustion engine with fuels based on hydrocarbons. The invention also relates to a fuel supply device for supplying fuel to an internal combustion engine having a fuel source for supplying hydrocarbons based on de-hydrogenatable fuel and a supply device for supplying fuel to the internal combustion engine.

In conventional motor vehicles fuel is passed in the form of gasoline or diesel from a tank to the designed as a gasoline engine or diesel engine internal combustion engine. In the case of aircraft, in particular airplanes or helicopters, today turbines are mostly used as internal combustion engines, which are supplied with fuel in the form of kerosene (for example jet A1) from the fuel tanks.

From the current state of the art, the injection methods described below for diesel engines, gasoline engines and turbines are known.

In a diesel engine, the injection methods can be distinguished essentially according to a compact combustion chamber and a divided combustion chamber. A split combustion chamber finds its application in chamber engines, which are assigned depending on the subdivision of the pre-chamber, swirl chamber and Lanova injection method. A one-piece combustion chamber is used for the direct injection, wherein the combustion chamber can be partially or completely in the piston head, as in particular in a so-called MAN-M method. For the aforementioned methods, various pump systems are used to build up the injection pressures. Engines with antechamber or vortex chamber injection use pump systems as single injection pumps, distributor injection pumps or in-line injection pumps. Engines that use direct injection use single pump injection pumps, in-line pumps, distributor injection pumps, unit injector systems or common rail injection as pumping systems.

More recent gasoline engines are increasingly using direct injection methods, as is the case with FSI and GDI engines, for example. In this case, the direct injection of the fuel in the combustion chamber is not bound to the inlet control times of the valves and thus can take place later in the compression phase. Thus, stratified charges, ie zones in the cylinder with different mixture composition are possible, such as the lean-burn engine. The lean-burn engine contains ignitable, rich or stoichiometric fuel ratio, i. H. 14.7 parts air: 1 part fuel, in the area of the spark plug and the lean mixture in the remaining combustion chamber.

Similarly, in modern steel engines, fuel is injected into a combustion chamber.

In all of the aforementioned injection methods, the same goal is always pursued in new developments, namely increase in performance, optimization of consumption and emission reduction. Here, adding hydrogen to fuel is one way to achieve those goals.

At present, processes are known in which ammonia or urea are successfully used as hydrogen carriers.

One known method of removing hydrogen from hydrocarbon mixtures is the PDh (partial dehydrogenation) process. In this case, part of the hydrogen is split off in an endothermic reaction of the hydrocarbon. The reaction is carried out in a reactor by means of a catalyst, for example a platinum catalyst based on a modified catalyst Carrier layer is located. To carry out the endothermic reaction, this heat must be added.

Known PDh methods are evident from WO 2007/071654 A1 and DE 10 2005 044 926 B3.

The object of the invention is to propose a method for operating a hydrocarbon-based internal combustion engine with which a performance increase, consumption optimization and / or emission reduction can be achieved in a particularly simple manner. In particular, a simple on-board provision of hydrogen to achieve these purposes should be proposed.

Next, a fuel supply device is to be created with which such a method can be performed.

This object is achieved by a method with the steps of claim 1 and a fuel supply device having the features of claim 9.

With the method according to the invention for operating an internal combustion engine with fuel based on hydrocarbons by partially dehydrating the fuel and introducing the partially dehydrogenated fuel together with the hydrogen into the internal combustion engine, an acceleration of the combustion and thus an increase in the efficiency can be achieved. In addition, the emissions of carbon, soot particles and nitrogen oxides are reduced. Furthermore, the maintenance effort can be reduced since the dehydrogenated fuel together with the hydrogen reduces soot formation by unburned hydrocarbons. In addition, the method reduces the expense of exhaust aftertreatment, so that no further and expensive devices for the exhaust aftertreatment are required. The fuel is advantageously partially dehydrogenated by means of a PDh catalyst. The PDh catalyst used allows a high hydrogen yield.

Advantageously, heat is supplied to the dehydrogenation, so that a better practicability of the method is ensured.

In a further embodiment, it is provided that heat is added from the internal combustion engine. Thus, no additional heat sources are needed.

Advantageously, the dehydrogenation takes place at a temperature between 200 and 450 ^° C. Within this temperature range, optimal performance of the dehydrogenation is ensured, which ultimately leads to increased hydrogen yield.

In a further advantageous embodiment of the partially dehydrogenated fuel and the hydrogen is passed without separation equal to the dehydrogenation in the internal combustion engine. As a result, only one feeding device from the dehydrating device to the internal combustion engine is required. Furthermore, no additional means for separating the partially dehydrogenated fuel and hydrogen is needed so that the complexity and cost of such a device can be reduced.

Advantageously, the resulting hydrogen in the partial dehydrogenation is dissolved in the liquid fuel or produced as bubbles in the liquid fuel, thereby enabling good transportability of the mixture.

In a further embodiment, it is provided that the partially dehydrogenated fuel is injected together with the hydrogen into the internal combustion engine becomes. The injection advantageously results in a very good atomization of the fuel mixture, which results in a more complete combustion.

In the method of the present invention, a fuel supply apparatus having a dehydrogenating means for partially dehydrating the fuel is used, the fuel source being connected to the dehydrating means for feeding the dehydrogenatable fuel to the dehydrating means, the feeding means being formed and connected to the dehydrating means in that it directs the partially dehydrated fuel to the internal combustion engine together with the hydrogen recovered from the dehydrogenatable fuel. The fuel supply device advantageously enables on-board generation of the hydrogen from the fuel. Thus, no additives are required, such as in conventional devices that carry additional methane to recover from hydrogen by dehydrogenation. Consequently, the use of the fuel for dehydration saves costs.

Advantageously, the dehydrogenator comprises a reactor containing a PDh catalyst.

In a further embodiment, the device is provided with a heat supply device for supplying heat from the internal combustion engine for use in partial dehydration. This eliminates an additional device that supplies heat to the dehydrogenation. Advantageously, this results in a weight and cost savings within the device.

Advantageously, the dehydrogenating device and / or the internal combustion engine is supplied exclusively with fuel from the fuel source.

Advantageously, an injection device for injecting the mixture of dehydrogenated fuel and hydrogen into the internal combustion engine is provided. hen. With the aid of an injection device, an advantageous atomization of the mixture takes place within the combustion chamber of the internal combustion engine, so that a better and more complete combustion is ensured.

In a further embodiment, it is provided that the method and the fuel supply device are used in a vehicle, in particular a motor vehicle, aircraft or watercraft.

In the vehicle advantageously an internal combustion engine is used, which is either a diesel engine, a gasoline engine or a turbine.

The invention will be explained in more detail by means of exemplary embodiments, which are shown schematically in the drawings. Hereby show:

Fig. 1 is a schematic representation of an advantageous embodiment of a fuel supply device for an internal combustion engine;

Fig. 2 is a schematic representation of an aircraft with jet engines as internal combustion engine and a further embodiment of a fuel supply device and

Fig. 3 is a schematic representation of a motor vehicle with a gasoline or diesel engine as an internal combustion engine and another

Embodiment of a fuel supply device.

1 shows an advantageous embodiment of a fuel supply device 10 for the partial dehydrogenation of a fuel 34. The fuel supply device 10 has a fuel source 22 with a fuel line 12, which converts the dehydrogenatable fuel 34 from the fuel source 22 into a dehydrogenated fuel. riereinrichtung 14, which is designed as a reactor and with a catalyst - PDh catalyst 36 - is provided directs. Subsequent to the dehydrating device 14, the dehydrogenated fuel together with the hydrogen 38 is introduced into an internal combustion engine 20 via a feed device 16, here in the form of a line. The introduction of the dehydrogenated fuel with the hydrogen 38 via an injector 17. In addition, the fuel supply device 10, a heat supply device 18, the waste heat - heat 40 - from the internal combustion engine 20 in the dehydrogenation device 14 initiates.

Hereinafter, a method practicable with the fuel supply apparatus 10 for operating the internal combustion engine 20 with hydrocarbon-based fuel 34 will be described. The dehydrogenatable fuel 34 is passed into a reactor with a catalyst. In the reactor, a catalytic reaction takes place, which extracts a small portion of the bound hydrogen from the fuel 34. Further details on this reaction and a device for carrying out this reaction can be taken from the German patent application DE 10 2007 036495.6-14, which is not previously published, to which reference is expressly made. The content of this earlier application also forms part of the present disclosure. This reaction carried out in the reactor is called partial dehydrogenation and is based on an endothermic reaction. Consequently, should the heat process are added out 40, with the preferred temperature range of the reaction at about 200 ° to 450 ⁰ C. After dehydrogenation, the hydrogen is either dissolved or as bubbles in the dehydrogenated fuel, depending on the pressure, temperature and amount. For example, the dehydrogenated fuel and the hydrogen 38 is present as a mixture, in particular as a dispersion. Subsequently, the dehydrogenated fuel is injected into the internal combustion engine 20 together with the hydrogen 38 - that is, for example, the dispersion produced during the dehydrogenation. There is therefore no separation of the mixture of dehydrogenated fuel and hydrogen 38 produced, but the mixture is passed to the internal combustion engine 20.

The procedure can be summarized as follows:

PDh -> hydrogen + dehydrogenated fuel -> turbine / petrol or diesel engine

The invention differs from previously known PDh methods, in particular in the form that immediately after the catalytic dehydrogenation the entire fuel is injected into the internal combustion engine 20 (turbine or gasoline or diesel engine).

This is a viable solution since hydrogen is known to increase the efficiency of combustion. With additional hydrogen in the liquid fuel, unlike the surrounding fuel, the hydrogen ideally starts combustion at a lower temperature and burns faster. Such distributed combustion causes faster and more complete combustion, although the fuel results in faster heat buildup in the combustion chamber of an internal combustion engine 20.

The bubbles formed in the mixture help to reduce the amount of soot and CO formed during combustion as more complete combustion occurs.

The method is also advantageous in the sense that a short-range hydrogen environment is formed which is injected into the turbines or gasoline or diesel engines to promote combustion.

The simple onboard delivery of hydrogen from fuel through the process described here makes it possible to meet the goals of increasing performance, emission Reduction, especially C, soot and NO _x , lower maintenance through a lower soot load, less effort for exhaust aftertreatment and no use of additives due to the simple onboard provision of hydrogen to achieve.

2 shows a practical exemplary embodiment of a fuel supply device 10 with reference to an aircraft 24. In this embodiment, the kerosene is conducted from one or more kerosene tanks 25 via the fuel line 12 into the centrally arranged dehydrogenating device 14 and then partially dehydrated. After the partial dehydrogenation, the partially dehydrogenated kerosene is injected into the turbine 26 together with the hydrogen via a feeder 16. The heat required for the reaction is transferred via the heat supply device 18, e.g. from the turbines 26 to the dehydrogenator 14, passed.

3 shows a further practical embodiment for the use of a fuel supply device 10 in a motor vehicle 28. In this embodiment, a gasoline or diesel fuel from a fuel tank 32 located in the rear area is conducted via the fuel line 12 into the dehydrogenating device 14 located between the two axles. in which the dehydrogenation of the gasoline or diesel fuel takes place. After dehydration, the partially dehydrated gasoline or diesel fuel is injected together with the hydrogen via a feed device 16 in a gasoline or diesel engine. Here too, starting from the gasoline or diesel engine via the heat supply device 18, the heat required for the reaction is introduced into the dehydrogenation device 14.

The dehydrating device 14 is in each case constructed as shown and described in the earlier German patent application DE 10 2007 036 495.6-41. It is expressly referred to for further details, also with regard to the dehydrogenation process. LIST OF REFERENCE NUMBERS

10 fuel supply device

12 Fuel line (for supplying the dehydrogenatable fuel) 14 Dehydrator

16 feeder (for co-feeding the partially dehydrated fuel and hydrogen)

17 injection device

18 heat supply device 20 internal combustion engine

22 fuel source

24 aircraft

25 kerosene tank

26 turbine 28 motor vehicle

30 petrol or diesel engine

32 fuel tank

34 (dehydrogenatable) fuel

36 PDH catalyst (for example, operated at 400 ⁰ C) 38 Partially dehydrated fuel and hydrogen

40 heat

Claims

claims

1. A method for operating an internal combustion engine (20) with fuel (34) based on hydrocarbons, characterized by partial dehydrogenation of the fuel (34) and introducing the partially dehydrogenated fuel together with the hydrogen (38) in the internal combustion engine (20) ,

2. The method according to claim 1, characterized in that the fuel (34) by means of a PDh catalyst (36) is partially dehydrated.

3. The method according to any one of the preceding claims, characterized in that for partial dehydration heat (40) is supplied.

4. The method according to claim 3, characterized in that heat (40) from the internal combustion engine (20) is added.

5. The method according to any one of claims 3 to 4, characterized in that the partial dehydrogenation takes place at a temperature between 200 ⁰ C and 450 ⁰ C.

6. The method according to any one of the preceding claims, characterized in that the partially dehydrogenated fuel and the hydrogen are passed without separation equal to the dehydrogenation in the internal combustion engine (20).

7. The method according to any one of the preceding claims, characterized in that the resulting hydrogen is dissolved in the dehydrogenation in the liquid fuel and / or generated as bubbles in the liquid fuel.

8. The method according to any one of the preceding claims, characterized in that the partially dehydrogenated fuel with the hydrogen (38) is injected jointly into the internal combustion engine (20).

A fuel supply apparatus (10) for supplying fuel (34) to an internal combustion engine (20), comprising a fuel source (22) for supplying hydrocarbon-based dehydrogenatable fuel (34) and a supply means (16) for supplying fuel internal combustion engine (20), characterized in that a dehydrogenating device (14) is provided for partially dehydrating the fuel (34), the fuel source (22) being connected to the dehydrating device (14) to produce the dehydrogenatable fuel (34). to the dehydrating device (14), wherein the feeding device (16) is designed and connected to the dehydrating device (14) in such a way that it supplies the dehydrated fuel together with the hydrogen obtained from the dehydratable fuel (34) to the internal combustion engine (20). passes.

10. The device according to claim 9, characterized in that the dehydrogenating device (14) comprises a reactor containing a PDh catalyst.

11. Device according to one of the preceding claims, characterized in that a heat supply device (18) for supplying heat (40) from the internal combustion engine (20) is provided for use in the dehydrogenation.

12. Device according to one of the preceding claims, characterized in that the dehydrating device (14) and / or the internal combustion engine (20) exclusively with fuel (34) from the fuel source (22) is supplied.

13. Device according to one of the preceding claims, characterized in that an injection device (17) for injecting the mixture of dehydrogenated fuel and hydrogen (38) is provided in the internal combustion engine (20).

14. Vehicle, in particular motor vehicle (28), aircraft (24) or watercraft with an internal combustion engine (20), according to one of the preceding claims.

15. Vehicle according to claim 14, characterized in that the internal combustion engine (20) is a gasoline or diesel engine (30) or a turbine (26).