Fuel Line Comprising Insulation, and Pressure Vessel System

Abstract

A pressure vessel system for a motor vehicle for storing fuel includes a plurality of pressure vessels that are combined to form a pressure vessel assembly. The pressure vessels, when mounted, are arranged substantially in parallel relative to one another, and the pressure vessels are fluidically interconnected via a common fuel line. The technology further relates to a fuel line comprising thermal insulation.

Claims

1-14. (canceled)

15. A fuel line for a pressure vessel system of a motor vehicle, the fuel line comprising: a wall; and thermal insulation provided in an interior of the wall, wherein the wall is configured to compensate mechanical loads resulting from internal pressure prevalent in the fuel line.

16. The fuel line according to claim 15, wherein at least one pipe at least conjointly forms the thermal insulation.

17. The fuel line according to claim 15, wherein a wall thickness of the thermal insulation is less than a wall thickness of the wall by a factor of at least 2.

18. The fuel line according to claim 17, wherein the factor is at least 5.

19. The fuel line according to claim 18, wherein the factor is at least 10.

20. The fuel line according to claim 16, wherein at least one gap is provided at least in regions between the wall and the at least one pipe.

21. The fuel line according to claim 20, wherein the at least one pipe is permeable to fuel at least in regions, whereby pressure in the at least one gap and pressure in an interior region of the at least one pipe at least approximate one another.

22. The fuel line according to claim 20, wherein the at least one pipe has at least one contact region in which the at least one pipe bears on the wall, and in other regions is spaced apart from the wall by the at least one gap.

23. The fuel line according to claim 20, wherein, during fueling, a flow rate of the fuel in the at least one gap is lower than in an interior region of the at least one pipe by a factor of at least 10.

24. The fuel line according to claim 23, wherein the factor is at least 100.

25. The fuel line according to claim 24, wherein the factor is at least 1000.

26. The fuel line according to claim 16, wherein the at least one pipe has at least one branch which is in each case fluidically connected to a rail connector for connecting a pressure vessel.

27. The fuel line according to claim 26, wherein at least one contact region is provided so as to be adjacent to the at least one branch.

28. The fuel line according to claim 16, wherein the at least one pipe is configured to be insertable into the interior of the wall.

29. The fuel line according to claim 15, wherein the insulation comprises an insulation coating applied to an inside of the wall.

30. The fuel line according to claim 15, wherein the wall comprises a metallic block in which at least one fuel duct is incorporated.

31. A pressure vessel system for storing fuel, the pressure vessel system comprising: a pressure vessel assembly comprising a plurality of pressure vessels fluidically connected to one another by the fuel line of claim 15, wherein the pressure vessels in an installed position are disposed substantially parallel to one another.

32. The pressure vessel system according to claim 31, wherein the fuel line is configured as a fuel rail, and wherein a shut-off valve is provided on the fuel line, and wherein the pressure vessels of the pressure vessel assembly are configured as communicating pipes.

33. The pressure vessel system according to claim 32, wherein no electrically activatable shut-off valves are provided between the pressure vessels and the fuel line.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0037] The technology disclosed herein will now be explained by means of the figures in which:

[0038] FIG. 1 shows a schematic view of the pressure vessel system;

[0039] FIG. 2 shows a schematic view of the fuel line 200 and of a plurality of pressure vessels 100;

[0040] FIG. 3a and FIG. 3b show cross-sectional views along the line A-A of FIG. 2 according to alternative embodiments; and

[0041] FIG. 4 shows a schematic view of detail G of FIG. 2.

DETAILED DESCRIPTION OF THE FIGURES

[0042] FIG. 1 shows a schematic view of the pressure vessel system of the technology disclosed herein. The filler neck 420 by way of a fuel line is fluidically connected to a distributor unit 410. A non-return valve which is specified to preclude a backflow toward the filler neck 420 can be provided in the distributor unit 410. The distributor unit 410 is fluidically connected to an on-tank valve 310 of the further pressure vessel 300 which can be disposed below the rear seat bench, for example. However, such a further pressure vessel 300 does not have to be provided. A shut-off valve, a temperature sensor, a burst-pipe protection and/or a filter can expediently be provided in the on-tank valve 310 (not shown to some extent here). In a further design embodiment, a TPRD can likewise be provided at the opposite end of the further pressure vessel 300.

[0043] A fuel line 406 connects the distributor unit 410 to a pressure reducer unit 430 in which a burst-pipe protection 432, at least one pressure sensor, at least one temperature sensor, a mechanical safety valve 436 as well as a pressure reducer 434 can presently be provided. Furthermore, a service interface 438 which is provided for discharging fuel is presently provided downstream of the pressure reducer 434.

[0044] The fuel line 402 connects the distributor unit 410 to the shut-off valve 210. The shut-off valve 210 (cf. FIG. 2) is an electrically activatable shut-off valve which is specified to isolate the fluidic connection of the pressure vessel assembly 10 from the remaining fuel supply system. The fuel line 200 here is configured as a fuel rail. The fuel line 200 is provided in or on the pressure vessel assembly 10. The fuel rail is a line from which rail connectors branch off for fastening the individual pressure vessels 100 (cf. FIG. 2). The fuel line 200 can be embodied as a mechanically stiff fuel rail in such a manner that the fuel rail does not burst even in the event of an intrusion during an accident. Alternatively, a comparatively flexible fuel line which is received in a line housing can be provided. The line housing serves to additionally protect the fuel line 200 in relation to mechanical intrusion. The individual pressure vessels 100 of the pressure vessel assembly 10 are disposed so as to be substantially parallel to one another and identically spaced apart from one another. These pressure vessels 100 here have substantially identical lengths. Depending on the installation space in which the pressure vessel assembly 10 is to be installed, individual pressure vessels 100 of the pressure vessel assembly 10 may differ in length and/or have different diameters. No further electrically activatable shut-off valves are preferably provided between the individual pressure vessels 100 and the fuel line 200 so that the individual pressure vessels 100 of the pressure vessel assembly 10 in the intended use of the pressure vessel system are fluidically connected directly to one another, like communicating pipes. The reference sign L here denotes the overall length of the fuel line 200.

[0045] The ends of the pressure vessels 100 that are connected to the fuel line 200 are the proximal ends of the pressure vessels 100. The ends of the pressure vessels 100 that are provided on the opposite side are those ends of the pressure vessels 100 that are distal in terms of the fuel line 120.

[0046] One TPRD, and advantageously also one temperature sensor, are in each case advantageously provided on the distal ends of the two outer pressure vessels 100, thus those pressure vessels 100 which in the view from above do not have any further pressure vessel 100 on each side. A TPRD is likewise provided in the housing or block of the shut-off valve 210. A TPRD is furthermore provided on or adjacent to that end of the fuel line that lies opposite the shut-off valve 210. The TPRDs, the sensors and the valves, if disposed locally on the same locations of the pressure vessels 100, or the fuel line 200, respectively, are advantageously provided in common housings or blocks, respectively, so that the number of interfaces to be sealed is advantageously minimized.

[0047] In a further design embodiment, it can be provided that the pressure vessel assembly 10 has only one temperature sensor. The only one temperature sensor can preferably be provided in or on or adjacent to the housing of the shut-off valve 210, respectively. In an alternative design embodiment, it can be provided that the sensor is provided on or adjacent to that end of the fuel line that lies opposite the end of the shut-off valve 210, respectively. This has the advantage that the manufacturing costs may be reduced. Furthermore, the interfaces for the TPRDs, provided at the distal ends of the pressure vessels, can therefore be of a smaller design because these interfaces only have the TPRDs and do not also have an additional temperature sensor. This may have an overall advantageous effect on the utilization of the installation space. Also, no electrical lines have to be routed to the distal ends of the pressure vessels. The temperature sensor may be expediently integrated in such a manner that the temperature sensor is specified to record the temperature during fueling as well as during retrieval. If only one pressure vessel assembly without any further pressure vessel (e.g., a rear seat tank) is provided, the pressure sensor from the pressure reducer unit could also be transferred into the housing of the shut-off valve. Advantageously, the pressure sensor may be provided in such a manner that the latter is provided between the fuel line 200 and the shut-off valve 210. In this way, a pressure measurement can be performed even in the event of a closed shut-off valve 210.

[0048] The fuel rail, and in particular the wall disposed in the fuel rail, and the thermal insulation may advantageously be configured so as to be substantially straight.

[0049] FIG. 2 shows the fuel line 200 and the shut-off valve 210 which is specified to isolate the pressure vessel assembly 10 from the remaining fuel supply system. A burst-pipe protection, a manual valve and/or a TPRD can be additionally provided in the housing of the shut-off valve 210, for example. The fuel line 200, which again is configured as a fuel rail, is fluidically connected to the shut-off valve 210. The fuel line 200 runs in a substantially straight line. A bore is provided in the interior of the fuel line 200. This bore may have been incorporated from one of the end sides. Alternatively, it can be provided that one bore is in each case provided from both end sides of the opposite ends of the fuel line 200, these bores meeting in the center. The at least one bore forms the internal wall of the wall 202 of the fuel line 200. The fuel line 200 here is formed by an aluminum block. This is however not mandatory. The thermal insulation 204 is provided in the interior of the wall 202. The thermal insulation 204 here is conjointly formed by a pipe. The pipe is expediently a polymeric material pipe which is preferably provided so as to be concentric in the wall 202. As can be seen in more detail in FIG. 4, branches 206 which establish fluidic connections to the individual pressure vessels 100 emanate from the insulation 204. A plurality of gaps 203 are provided at least in portions between the pipe and the wall 202.

[0050] FIG. 3a shows a sectional view A-A of the design embodiment of FIG. 2. It can be readily seen that the insulation 204, which is conjointly formed by the pipe, is configured so as to be spaced apart from the wall 202. The wall 202 here is formed by a metallic block in which a fuel duct has been incorporated. A gap 203 is configured between the pipe and the wall 202. The gap 203 here completely surrounds the pipe. It is apparent that an almost identical flow cross section for transporting the fuel during fueling is formed in comparison to the design embodiment of FIG. 3b, whereas the bore incorporated in the metallic block has a much larger cross section. A bore with such a diameter is easier to produce than the bore which is provided in the design embodiment according to FIG. 3b. This facilitates the production of the fuel line 200.

[0051] FIG. 3b shows a sectional view A-A of an alternative design embodiment in which the insulation 204 has been applied by coating. Almost the entire internal cross section of the wall 202 is available here for transporting the fuel during fueling.

[0052] FIG. 4 shows a schematic view of detail G of FIG. 2. The rail connector 207 serves for connecting a pressure vessel 100 (not shown). For reasons of simplification, the mechanical connector has been omitted here. The latter could be implemented in any suitable way. The rail connector 207 runs substantially perpendicularly to the direction of main extent of the fuel line 200. The pipe, which conjointly forms the insulation 204, here is again provided so as to be concentric in the interior of the bore provided in the metallic block. The branch 206 here is provided in the region of the rail connector 207. The branch 206 here comprises a plurality of passage openings 209 through which the fuel makes its way into the annular gap 205. Two contact regions 201 are provided here so as to be directly adjacent to the branch. In the contact regions 201, the pipe bears on the internal surface of the wall 202. In comparison to the other regions, e.g., those regions in which a gap 203 is provided, the contact regions 201 have an enlarged external diameter. The contact regions 201 serve for fastening and centering the insulation 204. One gap 203 is in each case shown here between the pipe and the wall 202, in each case adjacent to the contact regions 201. The gap 203 likewise contains fuel. In an expedient design embodiment, it is provided that overflow ducts, which connect the individual gaps 203 to the inner flow cross section of the pipe, are provided in the contact regions 201. The overflow ducts can be configured by grooves in the circumferential faces of the contact regions 201, for example. The fluidic connections to each gap 203 are expediently designed such that these gaps 203 do not form ducts with an intense flow passing through. This can be prevented in that openings or overflow ducts are provided only at one end of a gap. The gaps 203 thus preferably form dead volumes with stationary fuel. Such a design embodiment results in that each gap 203 transfers the heat from the atmosphere to the fuel only comparatively ineffectively. The flow rate of the fuel in the interior of the pipe of the insulation 204 during fueling is many times higher than the flow rate in the gap 203. In this way, an overall poorer thermal transfer from the fuel to the environment can be implemented, so that fuel which is heated to a lesser extent flows into the pressure vessel 100 that is distal in terms of the shut-off valve 210. In this way, an overall more uniform fuel temperature in the pressure vessels 100 can be achieved.

[0053] The term substantially (e.g., pressure vessels disposed substantially in parallel) in the context of the technology disclosed herein comprises in each case the exact property or the exact value (e.g., pressure vessels disposed in parallel) as well as variances which are in each case insignificant in terms of the function of the property/the value (e.g., tolerable variance from pressure vessels disposed in parallel).

[0054] The above description of the present invention serves only for illustrative purposes and not for the purpose of limiting the invention. Various variations and modifications are possible within the context of the invention without departing from the scope of the invention and its equivalents.