DE202015009958U1 - Device for refueling motor vehicles with liquefied gas - Google Patents

Abstract

Device (1) for refueling motor vehicles (2) with a fluid that is used as fuel and consists of liquefied gas, in particular liquefied natural gas, comprising at least one storage container (3), a cooling device, at least one delivery device, through which the fluid from the storage container (3) can be fed to at least one fueling device (4) for motor vehicles (2), and at least one line (5) serving to supply the fluid to the fueling device (4), characterized in that the line (5) has a media-carrying central pipeline (6) as a medium pipe and at least one further medium-carrying pipe (7, 8) arranged concentrically to the central pipe (6) and delimiting an annular space (9, 10) with the enclosed pipe (6), wherein the central pipe (6) and the at least an annular space (9, 10) of the supply or return of the fluid or a gas stream is used, and that the outer pipe (7) of a jacket pipe (11) vice is flat, with the jacket pipe (11) being thermally insulated from the outer pipe (7) and the central pipe (6) being designed as a metal corrugated pipe in such a way that the central pipe (6) and at least one media-carrying annular space (9, 10) are opposed to one another are not thermally insulated.

Description

The invention relates to a device for refueling motor vehicles with a fuel fluid made from liquefied gas, in particular liquefied natural gas, comprising at least one storage container, a cooling device, at least one delivery device, through which the fluid from the storage container can be fed to at least one refueling device, by means of which Motor vehicles can be refueled with the fluid, and at least one line serving to supply the fluid to the refueling device.

Such fuels, also referred to as cryogenic fuels, whose boiling point or critical temperature at the pressure prevailing in the storage tank is far below normal ambient temperatures, are becoming increasingly important due to the increased energy requirement and the increasing environmental pollution caused by conventional energy sources. They tend to evaporate easily as a result of pressure and temperature changes.

It is known to operate internal combustion engines in motor vehicles with natural gas. Since natural gas has a very low storage density at normal atmospheric pressure compared to diesel fuel and a lower volumetric calorific value than diesel, the natural gas is compressed to around 200 bar (CNG = Compressed Natural Gas) or liquefied by lowering the temperature to -162 °C (LNG = Liquefied Natural Gas) so that a sufficient amount of energy can be carried in the vehicle.

In the case of LNG, part of the natural gas is constantly evaporating due to the heat supplied by the environment. The gaseous part of the natural gas mainly contains the more volatile components of the gas, which have a higher vapor pressure or a lower boiling point. The withdrawal of part of the gaseous gas in the storage tank leads to an accumulation of higher hydrocarbons, in particular propane, in the cryogenic liquefied part of the natural gas over the long term. The high propane content can be harmful to internal combustion engines. In addition, the mixture composition changes over time, which is undesirable.

In addition to land vehicles, such as buses, trucks and passenger cars, motor vehicles are also understood to mean water vehicles and aircraft.

the EP 2 229 551 A1 relates to a coupling for supplying a cryogenic fluid, in particular LNG, to a motor vehicle tank. For this purpose, the clutch is connected to a control line which is pressurized with a control fluid, for example compressed air at 10 bar. The release of the control pressure on the control line leads to the release of the fluid flow in the main line for supplying the fluid, so that it is ensured that the operator of the clutch does not come into contact with the cryogenic medium.

According to the EP 0 779 470 A1 a pressure feed tank is connected via a feed line and a storage container via a return line to a coupling in order to refuel the motor vehicle with cryogenic fuel flowing out of the pressure feed tank via the coupling. The outlet of the supply line and the inlet of the return line are arranged in the liquid cryofuel of the pressure feed tank and the storage tank, so that the liquid cryofuel of the pressure feed tank can be routed to the clutch or to the motor vehicle tank and back to the liquid cryofuel of the storage tank via this connection . This enables the hose and the warm motor vehicle tank to be run cold, with the heated liquid or gaseous cryogenic fuel being fed to the liquid phase of the storage container.

the DE 195 01 332 A1 relates to a method for cooling a coaxial tube system of at least two coaxial tubes, spaced apart from one another, of a superconducting cable which is arranged in a thermally well-insulating sheath, with a liquid gas being passed through the inner tube. In order to keep both the inner pipe and the pipe surrounding the inner pipe at a temperature, the annular gap sealed off at the end between the inner pipe and the pipe surrounding it is filled with a gas or gas mixture whose condensation temperature preferably corresponds to the boiling point of the liquid gas flowing in the inner pipe is higher, so that the gas or a gas of the gas mixture condenses on the inner tube, and the condensate dripping down cools the outer tube.

From the DE 10 2004 038 460 A1 discloses a device for filling a container with liquid gas from a storage container, in which liquefied gas is removed from the storage container and fed to the container by means of a conveying device via a liquid supply line. Furthermore, gaseous gas is removed from the container to be filled, at least partially liquefied by cooling in a heat exchanger, and the liquefied gas is fed to the container to be filled.

the DE 16 50 060 A refers to a flexible conduit made of concentric corrugated tubing for the transport of liquids or gases for example for the flow and return of district heating pipes.

Furthermore, from the US 5,315,831A as well as the US 5,537,824A Filling stations are known through which natural gas-powered motor vehicles can be refueled with LNG and/or CNG.

Proceeding from this state of the art, the object of the invention is to significantly improve the device for refueling motor vehicles. In particular, thermal losses that occur should be minimized.

According to the invention, this object is achieved with a device according to the features of claim 1 . The further development of the invention can be found in the dependent claims.

According to the invention, a device is therefore provided in which the line has a media-carrying central pipeline as the medium pipe and at least one other media-carrying pipeline which is arranged concentrically or coaxially with the central pipeline and delimits an annular space with the enclosed pipeline, the central pipeline and the at least one The annular space serves to supply or return the fluid from the liquefied gas or a gas flow and the outer pipeline is surrounded by a concentric jacket tube, for example, as the outer tube, the jacket tube being thermally insulated from the outer pipeline, the central pipeline being designed as a metallic corrugated pipe and wherein the central pipeline and at least one media-carrying annulus are not thermally insulated from one another. The central pipeline and the at least one annular space serve to supply and return the fuel. The outer pipe is surrounded by a jacket pipe, also concentric, which encloses a thermal insulating material. The pipelines and the casing pipe are each designed as thermally self-compensating metallic corrugated pipes, with the central pipeline and the media-carrying annular space not being thermally insulated from one another. According to the invention, heat is thus extracted from the supplied fuel by the concentric design of the lines that is realized in this way, in order to cool or liquefy the gas. The coaxial dividing wall between the pipes forms an optimal exchange surface due to the design as a corrugated pipe and the resulting increased surface.

In addition, it is particularly advantageous if the pipelines and the jacket pipe are each designed as thermally self-compensating metallic corrugated pipes in order to create a particularly flexible line that can also be laid in comparatively small radii.

In addition, it has proven to be particularly practical if all the pipelines and the jacket pipe are arranged coaxially with one another.

In a further, also particularly promising modification of the invention, another pipeline dividing the annular space into an inner annular space and an outer annular space is arranged in the annular space between the central pipeline as medium pipe and the pipeline. This makes it possible to set up a "standby mode" in which fuel is continuously removed from the storage tank and conveyed through the central pipeline to a flow reversal area in a line section of the line facing away from the storage tank. The fuel is then pumped back into the storage tank through the inner annulus. This results in a continuous flow in the line, which can prevent undesired heating. In addition, a desired supply of fuel is available at all times for refueling, so that the refueling process can be started immediately as soon as the line is connected to the motor vehicle.

It is particularly advantageous if the outer annular space is designed to discharge the gas volumes displaced from the motor vehicle tank during refueling. The displaced gaseous volumes, also referred to as "boil-off gases", can thus be reliably routed through the outer annular space into the storage container without exchange with the fuel supplied to the motor vehicle, in order to liquefy them there again. An escape of the gaseous components from the motor vehicle tank into the environment can be avoided and undesirable environmental pollution can be prevented.

For this purpose, according to a particularly useful embodiment of the line, the outer annular space is equipped with a separate inlet opening and a separate outlet opening, so that the boil-off gas can be returned separately from the fuel, but through the same line.

Furthermore, it is particularly promising if the device has a storage container for LNG and the line connects the storage container to a refueling device. As a result, comparatively large distances between the refueling device and a central, for example underground, storage container can be overcome without any problems by means of the line will. In this way, the storage container can also be connected to a number of refueling devices at possibly different locations.

In another embodiment of the invention, which is also particularly useful, a leakage monitoring device is arranged in the outer annular space between the casing pipe and the outer pipeline. As a result, any leaks that occur as a result of damage or wear and tear can be detected quickly and reliably and the supply of fuel can be stopped. Methods for fiber-optic temperature measurement are suitable for this purpose, for example glass fibers being used as sensors for detecting leaks that occur. Alternatively, a pressure difference that occurs in the outer annular space can also be used as an indicator of a leak.

The annulus between the mandrel and the outer tubing could be thermally isolated by a vacuum. It is also particularly practical if a thermal insulating material is provided in the annular space between the jacket pipe and the outer pipeline, which has a foam, in particular a polyurethane foam (PUR) as an essential component. At the same time, the insulating material gives the cable high mechanical stability and resilience, so that the risk of damage is significantly reduced. In addition, the multiple walls prevent the escape of liquid or gaseous components into the environment. The line is preferably designed as a corrugated tube in a self-compensating manner with regard to its thermal expansion.

Furthermore, it is also advantageous if the line is provided at least in sections with a peripheral reinforcement made of a braid. Such a reinforcement comprises, for example, a woven mesh and/or a non-woven mesh, with the material of the reinforcement being able to be chosen at will. In this way, the mechanical properties are further improved.

• 1 eine Prinzipdarstellung einer erfindungsgemäßen Einrichtung mit einer Leitung für Treibstoff;
• 2 eine perspektivische, teilweise geschnittene Darstellung eines Leitungsabschnittes der in 1 gezeigten Leitung;
• 3 einen Stand-By-Betrieb der Einrichtung;
• 4 einen Entnahme-Betrieb der Einrichtung:
• 5 einen Stand-By-Betrieb einer Variante der Einrichtung;
• 6 einen Entnahme -Betrieb der in 5 gezeigten Einrichtung.

The invention permits various embodiments. To further clarify its basic principle, one of them is shown in the drawing and is described below. This shows in

• 1 a schematic representation of a device according to the invention with a line for fuel;
• 2 a perspective, partially sectioned representation of a line section in 1 shown line;
• 3 a stand-by operation of the device;
• 4 a withdrawal operation of the facility:
• 5 a stand-by mode of a variant of the device;
• 6 a withdrawal operation of the in 5 shown facility.

A device 1 according to the invention, intended for refueling various vehicles and watercraft, is described below with reference to FIG 1 until 4 explained in more detail. The device 1 enables various motor vehicles 2 to be refueled with a liquefied gas used as fuel, in particular liquefied natural gas (LNG). For this purpose, the device has a storage container 3 designed as an above-ground tank for storing the liquefied gas, to which a cooling device (not shown) is assigned in order to liquefy the gas by cooling it to a suitable temperature range below -160.degree. A line 5 embodied as a corrugated pipe is arranged between a respective refueling device 4 embodied as a filling station, which is equipped in a manner known per se for the various types of motor vehicle.

The structural design of the line 5 is based on the 2 explained in more detail. The line 5 has a media-carrying central pipeline 6 as a medium pipe, through which the fuel can be conveyed from the storage container 3 to the respective fueling device 4 . This is enclosed concentrically by two other media-carrying pipelines 7, 8, so that two media-carrying annular spaces 9, 10 are formed, the function of which is explained below with reference to FIGS 3 and 4 is explained. Finally, an outer jacket tube 11 is also provided as an outer tube, which encloses an annular insulating material 12 between the pipeline 8 and the jacket tube 11 in order to thermally insulate the line 5 in this way. In addition, the pipelines 6, 7, 8 and the casing pipe 11 are designed as thermally self-compensating metallic corrugated pipes. The central pipeline 6 and the media-carrying annular spaces 9, 10 are not thermally insulated from one another. Since the central pipeline 6 and the two media-carrying annular spaces 9, 10 are only separated by the wall surface of the respective pipelines 6, 7, but are not thermally insulated, the medium carried in the annular spaces 9, 10 is protected by the fuel carried in the central pipeline 6 Removed heat and cooled accordingly. The coaxial partition wall between the pipelines 6, 7, 8 forms an optimal exchange surface due to the design as a corrugated pipe. The concentric design also improves thermal insulation from the environment, as only a single outer insulation is required. To check the outer annular space 10 is between tween the jacket tube 11 and the pipeline 8 associated with a leakage monitoring device 13 and thus enables the continuous monitoring of the line for possible leaks.

In addition to the transport of the fuel serving central pipe 6 allow the two separate annular spaces 9, 10 between the concentric lines 7, 8 two different operating conditions, which are described below with reference to FIG 3 and 4 be explained in more detail. For one shows 3 a “standby mode” in which fuel is continuously removed from the storage tank 3 and conveyed through the central pipeline 6 to a flow reversal area 14 in front of a closed line end (not shown) in a line section facing away from the storage tank 3. The fuel is then conveyed back into the storage container 3 in the direction of the arrow 16 through the inner annular space 9 and two line connections 15 . This results in a continuous flow in the line 5, through which an undesired heating can be avoided.

On the other hand, the outer annular space 10 is used when the motor vehicle 2 is being refueled to discharge the gaseous volumes which are displaced from a motor vehicle tank and are also referred to as “boil-off gases”. These are passed from the motor vehicle tank through a separate inlet opening 18, the outer annular space 10 and an outlet opening 19 without a connection to the central pipeline 6 in the direction of arrow 17 into the storage container 3 in order to liquefy them there again. An escape of the gaseous components from the motor vehicle tank into the environment can be avoided and undesirable environmental pollution and hazards can be prevented. In this operating mode, the fuel is supplied simultaneously through the central pipeline 6 and through the line connections 15 and the first, inner annular space 9. In this way, the volume flow is increased and the refueling process is shortened accordingly.

In addition, in the 5 and 6 another variant of the device 1 is shown. The pipeline 6 is enclosed concentrically by only one media-carrying pipeline 7, through which a media-carrying annular space 9 is formed. An outer jacket tube 11 forms the outer tube, which encloses an annular insulating material 12 between the annular space 9 and the jacket tube 11, so as to thermally insulate the pipelines 6, 7. The central pipeline 6 and the media-carrying annular space 9 are not thermally insulated from one another, so that they are only separated by the wall surface of the pipeline 6, but are not thermally insulated.

As illustrated by directional arrows, both in the in 5 shown operating mode of the supply of liquefied natural gas as well as in the in 6 Circulation of the liquefied natural gas present in the storage tank through the pipeline 7 is set in each case for the operating mode shown for sucking off boil-off gases BOG. In this way, heat is extracted through the pipeline 7 from the liquid natural gas or boil-off gas alternatively routed in the pipeline 6 and this is correspondingly cooled, with the boil-off gases being able to be liquefied by the heat extraction.

Reference List

1

Facility

2

motor vehicle

3

storage tank

4

refueling facility

5

management

6

central pipeline

7

pipeline

8th

pipeline

9

annulus

10

annulus

11

casing pipe

12

insulating material

13

leakage monitoring device

14

reverse flow area

15

line connection

16

arrow direction

17

arrow direction

18

intake port

19

exhaust port

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• EP 2229551 A1 [0006]
• EP 0779470 A1 [0007]
• DE 19501332 A1 [0008]
• DE 102004038460 A1 [0009]
• DE 1650060 A [0010]
• US5315831A [0011]
• US5537824A [0011]

Claims (11)

Device (1) for refueling motor vehicles (2) with a fluid that is used as fuel and consists of liquefied gas, in particular liquefied natural gas, comprising at least one storage container (3), a cooling device, at least one delivery device, through which the fluid from the storage container (3) can be fed to at least one fueling device (4) for motor vehicles (2), and at least one line (5) serving to supply the fluid to the fueling device (4), characterized in that the line (5) has a media-carrying central pipeline (6) as a medium pipe and at least one further medium-carrying pipe (7, 8) arranged concentrically to the central pipe (6) and delimiting an annular space (9, 10) with the enclosed pipe (6), wherein the central pipe (6) and the at least an annular space (9, 10) for supplying or returning the fluid or a gas stream, and that the outer pipe (7) is surrounded by a jacket pipe (11). where the jacket pipe (11) is thermally insulated from the outer pipe (7) and the central pipe (6) is designed as a metal corrugated pipe in such a way that the central pipe (6) and at least one media-carrying annular space (9, 10) are opposed to one another are not thermally insulated. Device (1) according to claim 1 , characterized in that the pipelines (6, 7, 8) and the casing pipe (11) are each designed as thermally self-compensating metallic corrugated pipes. Establishment (1) according to claims 1 or 2 , characterized in that all the pipes (6, 7, 8) and the jacket pipe (11) are arranged coaxially to one another. Device (1) according to at least one of the preceding claims, characterized in that between the central pipeline (6) and the outer pipeline (8) there is a further pipeline dividing the annular space into an inner annular space (9) and an outer annular space (10). (7) is arranged. Device (1) according to at least one of the preceding claims, characterized in that the outer annular space (10) is designed to discharge the gas volumes displaced from the motor vehicle tank during refueling. Device (1) according to at least one of the preceding claims, characterized in that the outer annular space (10) is equipped with a separate inlet opening (18) and a separate outlet opening (19). Device (1) according to at least one of the preceding claims, characterized in that the device (1) has a storage container (3) for liquefied natural gas (LNG) and that the line (5) connects the storage container (3) to a refueling device (4 ) connects. Device (1) according to at least one of the preceding claims, characterized in that a leakage monitoring device (13) is arranged in the outer annular space (10) between the casing pipe (11) and the outer pipeline (8). Device (1) according to at least one of the preceding claims, characterized in that a thermal insulating material (12) is arranged at least in sections in the annular space (10) between the jacket pipe (11) and the outer pipe (8). Device (1) according to at least one of the preceding claims, characterized in that the line (5) is designed to be self-compensating. Device (1) according to at least one of the preceding claims, characterized in that the line (5) is equipped at least in sections with a peripheral reinforcement made of a reinforcement.

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