FUEL SUPPLY FOR AN INTERNAL COMBUSTION ENGINE

Abstract

A fuel supply system for an internal combustion engine includes a fuel tank and an air supply and venting device for the fuel tank. The air supply and venting device includes a hydrocarbon retention device and an air supply and venting path, structured and arranged to provide a gas exchange between the fuel tank and an environment. The hydrocarbon retention device includes at least one filter membrane that separates hydrocarbons from air. The at least one filter membrane is arranged in the air supply and venting path such that the air supply and venting path is covered by the at least one filter membrane to prevent hydrocarbons from escaping from the fuel tank into the environment through the air supply and venting path. The at least one filter membrane has hydrocarbon nanotubes.

Claims

1.-11. (canceled)

12. A fuel supply system for an internal combustion engine, comprising; a fuel tank and an air supply and venting device for the fuel tank, wherein the air supply and venting device includes a hydrocarbon retention device; the air supply and venting device including an air supply and venting path, structured and arranged to provide a gas exchange between the fuel tank and an environment, the hydrocarbon retention device including at least one filter membrane that separates hydrocarbons from air, wherein the at least one filter membrane is arranged in the air supply and venting path of the fuel tank such that the air supply and venting path is covered by the at least one filter membrane and prevents hydrocarbons from escaping from the fuel tank into the environment through the air supply and venting path; and wherein the at least one filter membrane has hydrocarbon nanotubes.

13. The fuel supply system according to claim 1, wherein the hydrocarbon retention device only has filter membranes for separating the hydrocarbons from air.

14. The fuel supply system according to claim 1, wherein the at least one filter membrane has graphene.

15. The fuel supply system according to claim 1, wherein the at least one filter membrane has hydrophilized, strongly cross-linked solvent-stable polymeric membranes.

16. The fuel supply system according to claim 1, wherein the at least one filter membrane has pores with a defined pore size such that fuel molecules are retained and air molecules can pass through the at least one filter membrane through the pores of the at least one filter membrane.

17. The fuel supply system according to claim 1, wherein the at least one filter membrane is a gas permeation membrane with a high selective permeability.

18. The fuel supply system according to claim 1, further comprising a flow generation device that drives a gas mixture, the flow generation device located in the fuel tank such that the gas mixture flows along the at least one filter membrane at least in some sections.

19. The fuel supply system according to claim 1, wherein at least one of: the at least one filter membrane is structured to retain hydrocarbons; and the at least one filter membrane is structured to retain air components.

20. An internal combustion engine for a motor vehicle, comprising: a fuel supply system, the fuel supply system including: a fuel tank and an air supply and venting device for the fuel tank, wherein the air supply and venting device includes a hydrocarbon retention device; the air supply and venting device including an air supply and venting path, structured and arranged to provide a gas exchange between the fuel tank and an environment; the hydrocarbon retention device including at least one filter membrane that separates hydrocarbons from air, wherein the at least one filter membrane is arranged in the air supply and venting path of the fuel tank such that the air supply and venting path is covered by the at least one filter membrane and prevents hydrocarbons from escaping from the fuel tank into the environment through the air supply and venting path; and wherein the at least one filter membrane has hydrocarbon nanotubes.

21. The internal combustion engine according to claim 20, wherein the hydrocarbon retention device only has filter membranes for separating the hydrocarbons from air.

22. The internal combustion engine according to claim 20, wherein the at least one filter membrane has graphene.

23. The internal combustion engine according to claim 20, wherein the at least one filter membrane has hydrophilized, strongly cross-linked solvent-stable polymeric membranes.

24. The internal combustion engine according to claim 20, wherein the at least one filter membrane has pores with a defined pore size such that fuel molecules are retained and air molecules can pass through the at least one filter membrane through the pores of the at least one filter membrane.

25. The internal combustion engine according to claim 20, wherein the at least one filter membrane is a gas permeation membrane with a high selective permeability.

26. The internal combustion engine according to claim 20, further comprising a flow generation device that drives a gas mixture, the flow generation device located in the fuel tank such that the gas mixture flows along the at least one filter membrane at least in some sections.

27. The internal combustion engine according to claim 20, wherein the at least one filter membrane is structured to retain hydrocarbons.

28. The internal combustion engine according to claim 20, wherein the at least one filter membrane is formed to retain air components.

29. A motor vehicle, comprising: an internal combustion engine, the internal combustion engine including: a fuel supply system, the fuel supply system including: a fuel tank and an air supply and venting device for the fuel tank, wherein the air supply and venting device includes a hydrocarbon retention device; the air supply and venting device including an air supply and venting path, structured and arranged to provide a gas exchange between the fuel tank and an environment; the hydrocarbon retention device including at least one filter membrane that separates hydrocarbons from air, wherein the at least one filter membrane is arranged in the air supply and venting path of the fuel tank such that the air supply and venting path is covered by the at least one filter membrane and prevents hydrocarbons from escaping from the fuel tank into the environment through the air supply and venting path; and wherein the at least one filter membrane has hydrocarbon nanotubes.

30. The motor vehicle according to claim 29, wherein the at least one filter membrane has graphene.

31. The motor vehicle according to claim 29, wherein the at least one filter membrane has hydrophilized, strongly cross-linked solvent-stable polymeric membranes.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In each case schematically,

[0021] FIG. 1 shows a schematic illustration of a first embodiment of a fuel supply system,

[0022] FIG. 2 shows a schematic diagram of a second embodiment of a fuel supply system,

[0023] FIG. 3 shows a schematic diagram of a hydrocarbon retention device of the fuel supply system from FIG. 2, and

[0024] FIG. 4 shows a schematic diagram of a hydrocarbon retention device of a fuel supply system according to a third embodiment.

DETAILED DESCRIPTION

[0025] A first embodiment of a fuel supply system 10 for an internal combustion engine 12 illustrated in FIG. 1 can be used, for example, in a motor vehicle, which is driven by means of this internal combustion engine 12, in order to provide fuel for the internal combustion engine. The fuel supply system has a fuel tank 14, in which the fuel for the internal combustion engine 12 can be stored. In addition, at least one fuel line 16 is provided, via which fuel can be guided to the internal combustion engine 12.

[0026] In order to facilitate the filling and emptying of the fuel tank 14, an air supply and venting device 18 is provided, by means of which gas, in particular air 25 between the environment 20 and an interior space 22 of the fuel tank 14 can be exchanged. Due to the air supply and venting device 18, a pressure compensation can take place in the interior space 22 of the fuel tank 14, so that fuel can be removed from the tank via the fuel line 16 without any problems. This likewise facilitates the filling of the fuel tank 14.

[0027] In order to prevent that the fuel, in particular the fuel vapors 23, can escape via the air supply and venting device 18 into the environment 20, a hydrocarbon retention device 24 is provided, which is arranged in an air supply and venting path 26 of the air supply and venting device 18.

[0028] The hydrocarbon retention device 24 thereby has a filter membrane 28, which is arranged in such a way that it completely closes the air supply and venting path 26. As a result, the gas, which is exchanged between the interior space 22 and the environment 20 by means of the air supply and venting device 18, has to pass through the filter membrane 28. The filter membrane 28 is thereby formed in such a way that it selectively retains hydrocarbons 23, that is, hydrocarbons 23 cannot pass through the filter membrane 28 or can pass through only very poorly, so that hydrocarbons 23 cannot escape into the environment 20 via the air supply and venting path 26.

[0029] Filter membranes 28 of this type can have, for example, several pores, which, due to the pore size, provide for a selection between large and small molecules. Due to the selection of the pore size, a selection can thus be made between the hydrocarbons 23, which are present in the fuel, and the molecules and atoms, which are typically present in particular in the air 25. The main components of the air 25, oxygen, nitrogen, and carbon dioxide, are in particular small compared to the hydrocarbon chains 23, which are usually present in gasoline or diesel.

[0030] Membranes of this type for the filter membrane 28 can further have graphene, which provides for a particularly high stability of the filter membrane 28. As a result, the pore size or particularly stable pores can furthermore be created systematically.

[0031] It is further possible that the filter membrane 28 has hydrocarbon nanotubes. These hydrocarbon nanotubes can likewise increase the stability of the filter membrane 28, so that the latter can be formed to be thinner as a whole. As a result, the gas exchange for the air particles 25 can be increased with consistent retention capacity for the hydrocarbons 23. In particular the surface of the filter membrane 28 can thus be reduced.

[0032] The filter membrane 28 can further have hydrophilized, strongly cross-linked solvent-stable polymers. Polymers of this type also have a high selectivity and retention capacity for the hydrocarbons 23.

[0033] Finally, it is also conceivable that the filter membrane 28 is a gas permeation membrane with high selective permeability. This means that the permeability for in particular the air components 25, such as oxygen, nitrogen, and CO2, is much higher than the permeability of the hydrocarbons 23 of the fuel. This can be attained, for example, by means of a different solubility and different diffusion coefficients for the air components 25 and or the hydrocarbon atoms 23, respectively.

[0034] A second embodiment of the fuel supply system 10 illustrated in FIG. 2 differs from the first embodiment of the fuel supply system illustrated in FIG. 1 in that a flow generating device 30 is provided, which drives the gas mixture, which is present in the interior space 22 of the fuel tank 14, in such a way that the gas mixture flows along the filter membrane 28 at least in some sections. As a result, a so-called “crossflow process” is at hand. As a result, concentration shifts at the filter membrane 28 can be prevented, so that a long-lasting consistent filtration effect or retention effect, respectively, for the hydrocarbons 23 is at hand.

[0035] For example, a flow channel 32 can be provided, in which the flow generating device 30 introduces the gas mixture from the interior space 22 of the fuel tank 14. The filter membrane 28 can cover an opening 34 between the flow channel 32 and the air supply and venting path 26. In the alternative or in addition, the filter membrane 28 can be wound cylindrically, so that a large filter surface is available. As a result, the gas mixture is guided past the filter membrane 28 along the flow channel, so that the “crossflow process” is made possible.

[0036] In the alternative, the flow generating device 30 can be formed in that fresh air 25 is sucked in from the environment via the filter membrane 28 to the engine when the engine is started, and the hydrocarbons 23 accumulated in the flow channel 32 are thus used for the combustion.

[0037] Apart from that, the second embodiment of the fuel supply system 10 illustrated in FIG. 2 corresponds to the first embodiment of the fuel supply system 10 illustrated in FIG. 1 with regard to setup and function, to the above description of which reference is made in this respect.

[0038] A third embodiment of the fuel supply system illustrated in FIG. 4 differs from the second embodiment of the fuel supply system 10 illustrated in FIGS. 2 and 3 in that the filter membrane 28 is formed in such a way that the filter membrane 28 is permeable for hydrocarbons 23, but largely retains the air components 25. As a result, the hydrocarbons 23 can likewise be separated from the air components 25.

[0039] Apart from that, the third embodiment of the fuel supply system illustrated in FIG. 4 corresponds to the second embodiment of the fuel supply system 10 illustrated in FIGS. 2 and 3 with regard to setup and function, to the above description of which reference is made in this respect.