The invention relates to a high-pressure feed line and a delivery system for the delivery, in particular of a gas, e.g., natural gas or hydrogen, from a refueling facility into a container, in particular a container of a vehicle at a refueling pressure of greater than 150 bar, preferably greater than 200 bar, in particular greater than 400 bar using such a high-pressure line. Pressures in the range of 150 bar to 400 bar, preferably 200 bar to 350 bar, in particular 200 bar to 250 bar are particularly preferred. These pressures are suitable in particular for the delivery of natural gas or hydrogen. A rapid and safe transfer of a gas from a pressure source, for example, from a refueling facility containing a gaseous medium, for example, natural gas or hydrogen, to a vehicle is to be achieved using delivery systems for gaseous media, e.g., natural gas, as described above.

Simple, trouble-free operability is particularly important in this case, so that even at high refueling pressures of greater than 150 bar, greater than 200 bar, preferably greater than 400 bar, trouble-free handling is made possible, in particular in cooperation with a filling coupling. The filling coupling can be implemented as a quick-connecting coupling. In addition to the high pressures, a characteristic of such delivery systems or lines, respectively, is also the extreme temperature ranges in the plus and minus range of - 50°C to +120°C, in particular -40°C to +85°C, under which the gaseous media, for example, natural gas, are guided into a container, in particular a vehicle tank.

In general, the filling coupling is connected to the refueling facility via a line, comprising at least one high-pressure line. The gas is conducted at high pressure from the refueling facility to the filling coupling and then into the vehicle via the line.

Parts of delivery systems, for example, rotary feedthroughs having a gas recirculation for filling vehicle tanks or high-pressure hoses are known, for example, from WO-A- 98/05898 or WO-A-2005/121626 of the applicant.

In this case, WO-A-98/05898 describes a rotary feedthrough in conjunction with a filling coupling, the filling coupling having a housing having a fluid inlet and a fluid outlet as well as multiple valves to ensure a secure seal of the filling coupling. To compensate for the twisting of the connection hose on the filling coupling, a rotary feedthrough was provided in WO-A-98/05898. A gas recirculation via a second line is also provided in WO-A-98/05898. The system of WO98/05898 had the disadvantages of the relatively large installation expenditure and installation space, since corresponding connections had to be provided in each case on the rotary feedthrough and on the hose side.

WO-A-2005/121626 again discloses a rotary feedthrough having gas recirculation.

Furthermore, WO-A-2005/121626 also discloses a line, the recirculation line being arranged coaxially to a high-pressure line in the line. However, in WO-A-2005/121626, the line is designed in such a manner that the high-pressure line extends in the interior of the line or the hose and the gas recirculation extends in the outer region of the hose.

The content of the disclosure of both WO-A-98/05898 and also WO-A-2005/121626 is incorporated in its entirety in the present application, without requiring an express reference thereto.

The hose or the line, respectively, disclosed in WO-A-2005/121626 had the

disadvantage that the gas recirculation occurred in the outer region of the hose or the line, respectively. As a result, the entire hose changed its dimensions in the event of ventilation, in particular also changed in length, which resulted in leak-tightness problems. In addition, the diameter of the line or the entire hose, respectively, was very large, since the internal high-pressure line had a minimum diameter of 1/2 inch. The weight, the size, and the difficulty in handling caused thereby of the hose according to WO-A-2005/121626 resulted as disadvantages therefrom.

A line for lower pressures is known from US-B-4, 517,404, in which a second line having smaller diameter is guided in the interior of a first line having large diameter. Both lines can transport different fluids. The line having large diameter is connected to a vacuum source and a liquid, for example, water, is conducted in the internal line. In US-A- 4,517,404, the line having large diameter, i.e., the external line, comprises a spiral- shaped reinforcement, in contrast thereto, the internal line is a non-reinforced line made of an elastomeric material.

A hose assembly having a support spiral is known from DE-C-28 32 763. The hose shown in DE-C-28 32 763 is a thin-walled hose for low pressures. In order to prevent buckling of such a hose because of the thin hose wall, DE-C-28 32 763 proposes a support coil lying inside the hose. Because of the thin wall, the hose known from DE-C- 28 32 763 is not suitable for high pressures.

DE-C-195 46 659 describes a device for refueling a vehicle, liquid cryogenic fuel being conveyed from a pressurized conveyor tank of a vehicle into the storage container of a vehicle. The cryogenic fuel is preferably LNG or methane and is supplied in the liquid phase to the storage container. This is performed at low pressures or normal pressure and very low temperatures, preferably of -163°C.

US-B-5,386,858 discloses a delivery system for liquid fuels, e.g., diesel fuels, the hose assembly comprising a first line having large diameter and a second line, lying inside the first line, having small diameter. The liquid fuel is conveyed from the storage container to the fuel nozzle in the internal second line. The first line having large diameter is used to exhaust fuel gases or fuel vapors. The delivery system known from US-B-5,386,858 is in the field of conventional liquid fuels and is not suitable for an application for gases, which are guided under high pressure from a storage vessel to a tank connecting piece and therefrom into a vehicle tanks.

The object of the invention is to avoid the above-mentioned disadvantages of the prior art and to provide a line or a hose, respectively, for a delivery system, in particular for gaseous media, for example, natural gas or hydrogen, which avoids the disadvantages of the prior art.

In particular the line or the supply hose, respectively, is also to allow a reliable conduction of gaseous media such as natural gas or hydrogen at very high pressures of greater than 150 bar, in particular greater than 200 bar, preferably greater than 400 bar, in particular in the range of 150 bar to 400 bar, preferably 200 bar to 350 bar, in particular 200 bar to 250 bar. Furthermore, it is also to be durable during refueling at low temperatures in the range of -50°C to +120°C, preferably -40°C to +85°C. Further requirements are low weight, small dimensions, and easy handling capability. In particular, the line is to allow a refueling device having simple construction, which can be operated by customers similarly to conventional refueling devices for liquid fuels.

This object is achieved according to the invention in that a line is provided, in particular for conducting a gaseous medium such as natural gas or hydrogen, for example, from a refueling facility into a container, in particular a container of a vehicle at a refueling pressure of greater than 150 bar, in particular greater than 200 bar, preferably greater than 400 bar, in particular in the range of 150 bar to 400 bar, preferably 200 bar to 350 bar, in particular 200 bar to 250 bar, having at least one high-pressure line and one gas recirculation line, the high-pressure line and the gas recirculation line being arranged coaxially one inside the other. It is provided according to the invention that in such an assembly, the gas recirculation line is arranged in the interior of the high-pressure line and the gas recirculation line has a stabilization device.

The stabilization device which is arranged in the interior of the gas recirculation line is implemented in particular as a wire, in particular wound in spiral form, and preferably as a stainless steel spiral.

Through the provision of a stabilization device for the gas recirculation line according to the invention, the pressure applied to the high-pressure line is prevented from

deforming the gas recirculation line or, in the extreme case, even blocking it.

The stabilization device is thus used for the purpose of absorbing the pressure which is externally applied by the high-pressure line to the gas recirculation line and stabilizing the gas recirculation line. In contrast to US-B-4, 517,404, in the invention, the internal line is provided with a stabilization device. In contrast, the spiral-shaped reinforcement in US-B-4, 517,404 is provided on the external line and is used, as in DE-C-28 32 763, as a buckle protection of the thin- walled hoses.

Through the coaxial arrangement of the gas recirculation line within the high-pressure line, the line can be smaller than in the prior art, in which the high-pressure line was arranged internally and the gas recirculation line was arranged externally. The diameter of the entire line having internal gas recirculation line then corresponds to the line diameter of only the high-pressure line of 1/2 inch, for example, as is known from WO- A-2005/121626. The total diameter of the line is therefore significantly reduced in relation to the line according to WO-A-2005/121626.

This prevents twisting and reduces the weight of the line, which is arranged between the filling coupling and the storage container. A further advantage, in addition to the weight reduction, is the simpler handling capability and reduction of the danger of twisting. The line, which is reduced in total diameter in relation to the hose known from WO-A- 2005/121626, allows a refueling device having simple construction for natural gas and/or hydrogen, which can be operated by the customer similarly to a conventional liquid fuel refueling device, e.g., for diesel or gasoline fuel. In particular, this affects the handling capability and the weight.

In addition, the invention prevents dimension changes of the line occurring if, as in the prior art, a gas surge is applied to the gas recirculation line, for example, by the gas recirculation.

It is particularly preferable if the stabilization device is arranged, in particular in spiral form, in the interior of the gas recirculation line. Through the arrangement of the stabilization device, for example, a spiral-shaped wire in the interior of the gas recirculation line, it is ensured that a gas is only applied thereto only briefly, specifically when the ventilation is carried out via the gas recirculation line. It is particularly preferable if the stabilization device is designed as somewhat smaller in diameter than the diameter of the gas recirculation line. In such a case, the stabilization device can be laid loosely in the gas recirculation line. This allows easy replacement, for example, in the event of wear.

A particularly suitable material both for strength and also for the corrosion resistance for the stabilization device, in particular in wire form, is a stainless steel.

It is particularly preferable if the line corresponds in its total diameter to the diameter of a high-pressure line, for example, of 1/2 inch, and the gas recirculation line has a gas recirculation line diameter which is in the range of 3.5 mm to 4.5 mm, i.e., corresponds to approximately half of the diameter of the high-pressure line, and the stabilization device has a somewhat smaller diameter than the gas recirculation line, whereby the stabilization device can be laid loosely in the gas recirculation line. The diameter of the entire line, or in the present case the high-pressure line internal diameter (D|j _ne ) is particularly preferably between 1/4 inch and 3/4 inch, in particular between 3/8 inch and 5/8 inch.

Lines having a diameter of the entire line of less than 1/4 inch, in particular less than 3/8 inch, or greater than greater than 3/4 inch, in particular greater than 5/8 inch, would also fundamentally be conceivable, but multiple problems would result therefrom.

If the diameter of the entire line or the high-pressure line internal diameter is less than 1/4 inch, the problem results that the remaining line cross-section for guiding the gaseous medium, natural gas or hydrogen here, in the gas recirculation line is so small that a sufficient flow rate for refueling is no longer provided, since the diameter of the internal gas recirculation hose cannot be selected as arbitrarily small because of the required wall thicknesses at the applied high pressures of greater than 150 bar. The required flow rate can be provided if the total diameter is selected as larger, however, if the diameter or the high-pressure internal line diameter is greater than 3/4 inch, in particular greater than 5/8 inch, the line becomes so heavy and inflexible that refueling is practically no longer possible.

Surprisingly, for a diameter of the entire hose or the high-pressure internal line diameter in the range 1/4 inch to 3/4 inch, preferably in the range 3/8 inch to 5/8 inch very preferably approximately 1/2 inch, the required flow rate for a refueling can be provided, on the other hand, the hose is still sufficiently flexible and light.

In addition, the line can have a spiral-shaped wire apparatus on the outer side as a type of buckle protection.

Through the line according to the invention, a line having gas recirculation line and high- pressure line arranged coaxially one inside the other is provided, in which the gas recirculation line lying inside the high-pressure line is protected from deformation under high pressures with the aid of a stabilization device, in particular in the form of a spiral spring, preferably made of metal, for example, stainless steel.

In addition to the line, a delivery system for gaseous media having such a line is particularly preferably provided.

The delivery system has a filling coupling and a container, from which the gaseous medium is provided via the line according to the invention to the filling coupling at high pressure and at low temperatures, as previously specified.

In order to connect the filling coupling, in which typically the high-pressure line is provided externally and the gas recirculation line is provided internally, and the container to the line according to the invention, it is provided that the line is connected using connection couplings to both the filling coupling and also the container, the connection couplings having at least one connection bore in the form of diagonal bores, so that the gas recirculation line, which is located in the interior of the high-pressure line, of the line according to the invention can be connected to the gas recirculation line of the filling coupling or the container, respectively. The diagonal bores are also used for the purpose of connecting the external high-pressure line to the high-pressure line of the filling coupling or that of the container. The connection coupling is preferably implemented in the form of a rotary feedthrough.

A rotary feedthrough is disclosed, for example, in WO-A-2005/121626, whose

disclosure is incorporated in its entirety in the present application.

A filling coupling having integrated rotary feedthrough is disclosed in WO-A-98/05898, the content of whose disclosure is incorporated in its entirety in the present application.

The delivery system according to the invention is used above all at fueling stations for vehicles, in particular motor vehicles.

The invention is to be explained and described in greater detail hereafter on the basis of the figures, without restriction thereto.

In the figures:

Figures 1a-1b: show an embodiment of a line according to the invention in the form of a hose having internal gas recirculation line and external high-pressure line;

Figures 2 and 3: show the embodiment of a connection coupling on a filling coupling, implemented as a rotary feedthrough having internal high-pressure line and external gas recirculation line arranged coaxially one inside the other; Figures 4 and 5: show the embodiment of a connection coupling on a container, implemented as a rotary feedthrough having separate high-pressure line and separate gas recirculation line.

Figures 1a and 1b show a side view of a line 1 according to the invention for a delivery system, as is described in greater detail in Figures 2 to 5. The line 1 is implemented according to the invention in such a manner that a recirculation line 3, in particular a gas recirculation line, is arranged in the interior of the line 1 , the high-pressure line 7 being implemented in the line 1 between the outer wall of the hose 5 and the internal recirculation line 3. In the high-pressure line, in particular natural gas or hydrogen gas is guided at high pressure of greater than 150 bar, preferably greater than 350 bar, in particular greater than 400 bar, very preferably in the range of 150 bar to 400 bar, preferably in the range of 200 bar to 350 bar, particularly preferably 200 bar to 250 bar, into the tank (not shown) of the vehicle located on the side 9.1 of the line 1. The gas is taken from a container (not shown) on the side 9.2.

Connection parts 15.1 , 15.2 are provided in the region of the connections 9.1 , 9.2. The connection parts 15.1 , 15.2 have a transition 16.1 , 16.2 for the hose 1 and a

feedthrough (not shown) for the gas recirculation line 3 lying in the hose. Seals 20.1 , 20.2 are provided on the recirculation line 3. The gas recirculation line 3 has an insert 48 in the shape of a fir tree in the region of the connections 9.1 , 9.2, as shown in the detail view in Figure 1b. As a result, the gas recirculation line can be connected tightly to the provided connections of the connection couplings, as shown in Figures 2-5.

Through the externally acting pressure, the hose is pressed so strongly into the depressions of the fir tree profile that this hose does not have to be secured further, e.g., by a hose clamp. The connection parts also have recesses 22, in which parts of the connection couplings can be inserted, as shown in Figures 2 to 5, to provide a leak- tight connection of the line 1 to the connection couplings. On the outer side or outer wall of the hose 1 , spiral springs 13.1 , 13.2 are provided in the region of the connections 9.1 , 9.2 as a buckling protection as in tank hoses for liquid fuels, e.g., gasoline. This embodiment is advantageous, but not compulsory for the invention. Figure 1 b shows the region of the connection 9.2 of the line 1 according to Figure 1a in detail. In order to stabilize the internal gas recirculation line 3 at the applied high pressures of greater than 150 bar, in particular greater than 350 bar, preferably greater than 400 bar, in particular in the range of 150 bar to 400 bar, preferably 200 bar to 350 bar, in particular 250 bar to 350 bar, as shown in Figure 1b, a stabilization device 50 is provided on the inner side 52 of the hose 54 of the gas recirculation line. The stabilization device is preferably a wire having a diameter in the range of 0.1 mm to 1 mm. The material of the wire of the stabilization device is a metal, preferably steel, in particular stainless steel. The internal diameter D|j _ne , which is also designated as the total diameter of the entire line or high- pressure line internal diameter, is preferably, without being restricted thereto, 1/2 inch. It is particularly advantageous if the internal diameter D| _ine is in the range 1/4 inch to 3/4 inch, preferably in the range 3/8 inch to 5/8 inch.

Lines having a total diameter or high-pressure line internal diameter of less than 1/4 inch, in particular less than 3/8 inch, or greater than 3/4 inch, in particular greater than 5/8 inch, would fundamentally also be conceivable, but multiple problems result therefrom.

If the diameter of the entire line is less than 1/4 inch, the problem results that the remaining line cross-section for guiding the gaseous medium, natural gas or hydrogen here, is so small that a sufficient flow rate for refueling is no longer provided, since the diameter of the surrounding gas recirculation hose cannot be selected as arbitrarily small because of the required wall thicknesses at the applied high pressures of greater than 150 bar.

The required flow rate can be provided if the total diameter is selected as larger, however, if the diameter is greater than 3/4 inch, in particular greater than 5/8 inch, the line becomes so heavy and inflexible that refueling is practically no longer possible.

Surprisingly, for a diameter of the entire hose in the range 1/4 inch to 3/4 inch, especially in the range 3/8 inch to 5/8 inch very preferably of approximately 1/2 inch, the required flow rate for a refueling can be provided, on the other hand, the hose is still sufficiently flexible and light.

The internal diameter D _gas of the gas recirculation line is preferably in the range of 3.3 mm to 4.3 mm, while in contrast the external diameter D _sp irai of the stabilization device 50 is in the range of 3.5 mm to 4.5 mm, so that the stabilization device 50 can be laid loosely in the interior of the gas recirculation hose. This allows a rapid replacement. Furthermore, the insert 48 having the seal 20.2 for connection to the connection part (not shown) can be recognized well in Figure 1b. The insert 48 is in the shape of a fir tree having external ribs 56. If the hose 54 of the gas recirculation line is under pressure because of the gas guided through the high-pressure line 7, the hose automatically seals off tightly with the insert 48. The connection part 15.2, the installation 16.2, and the external spring 13.2 can also be recognized well in Figure 1b.

In Figure 2 and Figure 3, a connection coupling designed as a rotary feedthrough is shown, in which, in the rotary feedthrough, the feed line, i.e., the high-pressure line is guided coaxially in the recirculation line to connect the line according to Figures 1a-1b to a filling coupling (not shown) of a delivery system.

Figure 2 shows a connection coupling 100, with which a line 1 (not shown) can be connected to a filling coupling via a rotary feedthrough 200. The connection coupling 100 in Figure 2 is not yet connected to a hose according to Figure 1. However, the connection coupling 100 is connected in the present case to a rotary feedthrough 200 and, adjoining thereon, to a filling coupling (not shown).

The connection coupling according to Figure 2 has a connection region 110, which can be connected to the connection part of the hose according to Figures 1a-b and is designated therein with 15.1. The connection part 110 comprises a receptacle 112 for the gas recirculation line extending in the line or the hose, respectively, according to Figures 1a-b, and a high- pressure line region 114.

The connection between the line shown in Figures 1a-b and the filling coupling with the aid of the connection coupling 100 and rotary feedthrough 200, is executed in detail in Figure 3.

Furthermore, the connection bore(s) 120 as diagonal bore(s) can be recognized in Figure 2, which, to discharge the recirculated gas from the recirculation line 3 lying inside the hose according to Figures 1a-1b, open into the external recirculation line 220.1 , 220.2 of the rotary feedthrough 200, as described, e.g., in WO-A-2005/121626 A1. The diagonal bore 130 implemented in the region of the connection coupling 100 for connecting the internal high-pressure line 230 in the rotary feedthrough 200 and the filling coupling adjoining thereon to the external feedline 7 in the hose according to Figure 1 can also be recognized.

Figure 3 shows in detail the connection of a line 1 according to Figures 1a-b to the rear part of a filling coupling 300, which opens into a tank of a vehicle, and to a rotary feedthrough 200 adjoining the connection coupling 100. Identical components as in Figures 1a-1 b and 2 are provided with the same reference numerals.

As is also clearly shown in Figure 3, the seal 20.1 of the insert 48 of the gas

recirculation line 3 engages in the opening 112 of the connection coupling 100, so that the gas recirculation line 3 is separated from the high-pressure part 114 of the

connection part 100, through which gaseous medium is supplied at high-pressure from the external high-pressure line 7 of the line 1 into the internal high-pressure line 230 of the connection coupling 100 or the rotary feedthrough, respectively. The diagonal bores 120, 130 for connecting the gas recirculation line 3 to the external gas recirculation line 220.1 , 220.2 of the rotary feedthrough 200 and for connecting the high-pressure line 230 of the feedthrough 200 to the high-pressure line 7 of the line 1 can be recognized clearly. Furthermore, the stabilization device 52 arranged inside the gas recirculation line 3 can be recognized clearly.

Figure 4 shows a connection coupling 300 having integrated rotary feedthrough 400 according to, for example, WO-A-98/05898, the content of whose disclosure is incorporated in its entirety in this application, for supplying gas under high pressure from a storage tank (not shown).

Like the embodiment according to Figure 3, the embodiment of the connection coupling 300 also has an diagonal bore 320. The gas recirculation line 3 is, as in Figure 2, inserted tightly into the opening 312 and the recirculated air is guided to the recirculation line or a recirculation opening 310, which is arranged separately for the feedline for the gas under high pressure, via the diagonal bore 320. The high-pressure line 300, via which the gas is guided from a storage container (not shown) to the line 1 , is connected via the bore 330 to the external high-pressure line 7 in line 1 according to Figure 1.

Figure 5 shows the connection of the connection coupling 300 having integrated rotary feedthrough 400 to line 1. Line 1 is constructed according to Figures 1a-1b and has an internal gas recirculation line 3 in a hose 5, so that the gas under pressure, which can preferably be natural gas or hydrogen, for example, is supplied from a storage container (not shown) to the high-pressure part 7 of the line 1. Identical components as in Figures 1a-1b have identical reference numerals. In particular, the gas recirculation line 3 has a stabilization device, for example, a metal wire 48.

For the first time, a simply constructed line for a delivery system for gases at high pressures of greater than 150 bar is specified by the invention, which is suitable, through high reliability and universal connectability to different types of connection couplings, for connection to storage container and filling coupling. Further advantages of the line are in particular the high stability of the hose even under very high pressures and the high resistance at very low temperatures. This is also achieved in particular by the stabilization device. Furthermore, the hose has a relatively low weight, and the danger of twisting is low.

A further advantage is that it is possible using the line according to the invention to provide a delivery system, in particular a refueling device for gases, in particular for natural gas and hydrogen, which has a simple construction and can be operated by customers similarly as a conventional liquid refueling device.