DE102011075302A1 - Gas tank e.g. fuel tank for energy conversion system installed in e.g. vehicle, has gas storage portion whose size is varied reciprocally to size of restrictor portion receiving displacement portion to change liquid or solid/gas phase - Google Patents

Abstract

The gas tank has a gas container (1) having a gas storage portion (2) and restrictor portion (3). A separator (4) arranged between the gas storage portion and restrictor portion. The size of the gas storage portion and size of the restrictor portion change are changed by changing the position of the separator. The size of the gas storage portion is varied reciprocally to the size of restrictor portion. The restrictor portion is adapted to receive a displacement portion under the specific operating conditions to carry out liquid/gas or solid/gas phase change. An independent claim is included for method for operating gas tank.

Description

The present invention relates to a gas storage, in particular fuel gas storage, an operating method for this and correspondingly equipped energy conversion systems, vehicles, buildings or technical equipment.

State of the art

In addition to solid and liquid fuels, there are also gaseous fuels. The latter, unlike the former, have the property of being compressible. That is, their relatively low density increases with increasing pressure. For acceptable tank sizes, especially in automotive applications, they are therefore stored under elevated pressure in pressure vessels. For example, natural gas can be stored in a pressure vessel at a nominal pressure of up to about 200 bar and hydrogen at a pressure of up to about 700 bar.

Without a feed pump, however, a pressure tank can only be emptied to a pressure above or equal to the operating pressure of the consumer connected downstream. For automotive fuel cell systems, for example, which receive hydrogen via a pressure regulating valve, according to the current state of the art, a pre-pressure of about 20 bar is required in order to be able to produce a sufficient fuel mass flow with acceptable valve cross sections. This applies in a similar way to natural gas vehicles.

In addition, refillable pressure vessels are preferably not evacuated to normal pressure, but, for example, only to a minimum pressure in order to exclude the entry of contaminants into the tank during refilling with certainty.

For these reasons, conventionally remains a non-recyclable fuel residue in the pressure tank.

The publication DE 10 2004 063 071 A1 describes a fuel gas tank for low pressure applications, which has a variable storage volume to realize complete emptying of stored fuel.

Disclosure of the invention

The present invention is a gas storage, in particular fuel gas storage, which comprises a gas container, wherein the gas container, a gas storage volume, in particular a fuel storage volume, a Verdrängermittelvolumen and arranged between the gas storage volume and the Verdrängermittelvolumen separator and a gas inlet and / or outlet for gas extraction and / or Gas filling of the gas storage volume, in particular a fuel inlet and / or outlet for fuel extraction and / or fuel filling of the fuel storage volume comprises. In this case, the size of the gas storage volume and the size of the displacement means volume can be changed under a change in position of the separating element, in particular wherein the size of the gas storage volume is reciprocally variable to the size of the displacement means volume. In other words, the size of the gas storage volume can be reduced below an increase in the volume of the displacer means and can be increased with a reduction in the volume of the displacer means. Furthermore, according to the invention, the displacer means volume is designed to accommodate a displacer means, which undergoes a liquid / gas or solid / gas phase change under the operating conditions within the displacer volume.

The gas storage device according to the invention, in particular fuel gas storage, advantageously makes it possible to significantly increase the usable storage capacity, with otherwise constant external volume of the gas storage, in particular fuel gas storage, as well as maintaining a minimum tank pressure. An increase in usable storage capacity, in turn, has the advantage that, if necessary, the installation space can be reduced. By maintaining the installation space, however, a supply with a higher energy or over a longer period can be provided. In particular, in the energy supply of vehicles this is accompanied by the advantage that a higher range can be achieved and a smaller number of filling stations is needed. In addition, a substantially complete tank emptying at full power or high mass flow is possible because the pressure in the gas tank does not fall below the adjustable by the displacement means of the invention minimum pressure, for example, 20 bar. This advantage increases in particular both in the direction of smaller maximum memory pressures and in the direction of higher memory minima pressures. Advantageously, it is therefore not necessary to lower the pressure on the removal side of the gas container.

According to the invention, the change in the gas storage volume, in particular fuel storage volume, based on the gas sampling, in particular fuel extraction, and the use of a displacer with a liquid / gaseous or solid / gaseous phase change and a consequent sudden change in density. The gas storage device according to the invention, in particular fuel gas storage, has the advantage that it can be used with a smaller footprint and without Activation of the volume changes by other devices, such as the exhaust of an internal combustion engine. This advantageously allows a wider range of uses of the gas storage device according to the invention, in particular fuel gas storage. Advantageously, the gas storage device according to the invention, in particular fuel gas storage, therefore, not only for the gas or energy supply of a vehicle, but also a building or a technical system can be used. In addition, the invention advantageously improves use as and for portable applications, for example in the form of a portable or replacement tank, or a portable, gas powered device, such as fuel cell based.

In the context of the present invention, a container may in particular be understood to mean a self-contained hollow body. It is possible that, for example, one or more valves may be integrated into the wall of the hollow body closed in itself as such.

The gas inlet and / or outlet, in particular fuel inlet and / or outlet, may be, for example, an extraction and / or filling fitting for pressurized gas containers, in particular based on one or more valves. It is possible that a device acts both as a gas inlet and as a gas outlet. However, it is also possible that the gas storage volume has a gas inlet device and a separate gas outlet device. In particular, the gas storage, in particular fuel gas storage, comprise at least one gas inlet and / or outlet valve. For example, the gas inlet and / or outlet or the gas inlet and / or outlet valve, in particular automatic, can be opened and closed or adjusted. Preferably, the gas inlet and / or outlet is a valve which can function both as a gas inlet valve and as a fuel outlet valve.

The term of a liquid / gaseous phase change may in particular comprise both a phase change from the liquid to the gaseous and from the gaseous to the liquid form.

In particular, the term "solid / gaseous phase change" can encompass both a phase change from the solid to the gaseous and from the gaseous to the solid form.

In principle, it is possible to fill the displacer means volume, in particular once, with the displacer in the production of the gas accumulator, in particular the fuel gas accumulator. To simplify the production and to improve the maintainability, in particular for replenishment of displacer in the event of displacer loss over the life of the gas storage, in particular fuel gas storage, and associated with optimizing the life of the gas storage, especially fuel gas storage, the displacer means volume is also considered to be advantageous make the displacer fillable.

In one embodiment, the gas accumulator therefore further comprises a displacer inlet valve for filling the displacer means volume with displacer means.

In the context of a further embodiment, the gas container is a pressurized gas container, in particular a high-pressure gas container. In this case, a high-pressure gas container can be understood to mean in particular a gas container which is suitable for an internal pressure of ≥ 50 bar, for example ≥ 100 bar or ≥ 150 bar, for example for natural gas storage, or even ≥ 500 bar, for example ≥ 700 bar, for example for hydrogen storage, is designed.

During operation of the gas accumulator, in particular a pressure within a pressure range of ≥ 2 bar to ≤ 800 bar, for example of ≥ 2 bar or ≥ 10 bar or ≥ 15 bar or ≥ 20 bar to ≤ 800 bar or ≤ 200 bar or within the displacement means volume ≤ 100 bar, and a temperature within a temperature range of ≥ -40 ° C to ≤ 85 ° C, for example, from ≥ -40 ° C to ≤ 50 ° C, are present. In particular, the displacer can perform the liquid / gas or solid / gas phase change within this pressure and temperature range.

Within the scope of a further embodiment, therefore, the displacer performs within a pressure range of ≥ 2 bar to ≤ 800 bar, for example ≥ 2 bar or ≥ 10 bar or ≥ 15 bar or ≥ 20 bar to ≤ 800 bar or ≤ 200 bar or ≤ 100 bar , and within a temperature range of ≥ -40 ° C to ≤ 85 ° C, in particular from ≥ -40 ° C to ≤ 50 ° C, a liquid / gaseous or fixed / gaseous phase change. In this pressure and temperature range, for example, carbon dioxide and krypton undergo a liquid / gas phase change.

In another embodiment, therefore, the displacer comprises or is carbon dioxide (CO ₂ ) and / or krypton (Kr). Preferably, the displacer is carbon dioxide. For carbon dioxide suggests that this is safe and cheap to procure. In particular, the displacer means volume carbon dioxide (CO ₂ ) and / or krypton (Kr), in particular carbon dioxide.

The type and quantity of the displacement means can be adjusted specifically with regard to the following technical features.

In the case of a maximum gas filling, in particular fuel filling, of the gas storage volume in the displacer volume, the displacer is preferably at least partially, if appropriate substantially completely, in liquid or solid form. In the case of a, in particular substantially complete, gas removal, in particular fuel extraction, from the gas storage volume, the displacer is preferably present in the displacer volume at least partially, optionally substantially completely, in gaseous form.

In the context of a further embodiment, in the case of a, in particular substantially complete, gas removal, in particular fuel extraction, from the gas storage volume within the displacement means volume a pressure of ≥ 2 bar, for example of ≥ 10 bar or ≥ 15 bar or ≥ 20 bar before. Thus, advantageously, a sufficient fuel mass flow can be represented with acceptable valve cross sections and in particular the penetration of contaminants into the tank in the deflated state can be prevented.

In the context of a further embodiment, in the case of a, in particular substantially complete, gas extraction, in particular fuel extraction, from the gas storage volume, the displacer means volume and the separating element occupy substantially all of the volume available in the interior of the gas container. Thus, advantageously, a high usable storage capacity can be achieved.

In the case of a maximum gas filling, in particular fuel filling, the gas storage volume, for example, more than 90 vol .-%, for example more than 97 vol .-%, and / or the displacer volume less than 10 vol .-%, for example less than 3 vol. %, of the total volume available inside the gas container. In a gas storage device according to the invention, in particular fuel gas storage, advantageously more than 90% by volume, for example more than 97% by volume, of the available volume for gas storage, in particular fuel storage, can be used effectively. A small part of the total volume available inside the gas container is occupied by the separating element. However, the volume occupied by the separating element can be low, in particular as a result of an embodiment of the separating element as a membrane, since the membrane must withstand only small pressure gradients due to the design and can therefore be made relatively thin.

In the context of a further preferred embodiment, the separating element is therefore an elastically extensible, in particular gas-tight, membrane.

In a further embodiment, a self-contained, in particular bubble or balloon-shaped, hollow body is arranged with a wall of an elastically extensible material within the gas container, wherein the wall serves as a separating element and the inner volume as Verdolängermittelvolumen. In this case, it is possible for a valve, in particular for the admission of displacer means, to be integrated in the wall of the hollow body, which is closed as such, in the displacer volume. This embodiment has the advantage that in a simple and cost-effective manner, an inventive gas storage, in particular fuel gas storage, can be achieved with a particularly high usable storage capacity.

In another embodiment, the separating element is a displaceable wall element. A displaceable wall element, which may be performed, for example, similar to a piston, represents a further implementation possibility.

Within the scope of a further embodiment, the gas reservoir has a displacement medium reservoir, wherein the displacement agent reservoir is fluidically connected to the displacement medium volume. The displacer means reservoir may in particular be designed to receive the displacer in liquid or solid form. Thus, the maximum available for gas storage volume can advantageously be further increased. The displacer reservoir may be provided with the displacer inlet valve.

In a further embodiment, the gas storage volume is designed to receive natural gas and / or hydrogen. In particular, the gas storage volume may therefore comprise natural gas and / or hydrogen. The term natural gas can be understood in particular as an override for fossil and chemically and / or biologically produced gases based on alkane, such as natural gas, biogas, methane, ethane, propane and / or butane-containing gases. In particular, the gas storage volume may be designed to accommodate or comprise compressed natural gas, in particular natural gas (CNG).

• – Befüllen des Gasspeichervolumens, insbesondere Brennstoffspeichervolumens, mit dem Gas, insbesondere Brennstoff; und
• – Befüllen des Verdrängermittelvolumens mit dem Verdrängermittel.

Another object of the present invention is an operating method for a gas storage device according to the invention, in particular fuel gas storage, comprising the method steps:

• - filling the gas storage volume, in particular fuel storage volume, with the gas, in particular fuel; and
• - Filling the displacement means volume with the displacer.

Preferably, the type and amount of the displacement means is selected such that the displacement means in the case of a maximum gas filling, in particular fuel filling, the gas storage volume in the displacer means volume at least partially, optionally substantially completely, in liquid or solid form and in the case one, in particular substantially complete, gas extraction, in particular fuel extraction, from the gas storage volume in the displacer volume at least partially, optionally substantially completely present in gaseous form.

Within the scope of a further embodiment, the type and quantity of the displacement means are selected such that in the case of a, in particular substantially complete, gas extraction, in particular fuel extraction, from the gas storage volume within the displacement means volume a pressure of ≥ 2 bar, for example ≥ 10 bar or ≥ 15 bar, in particular of ≥ 20 bar, is present.

Within the scope of a further embodiment, the type and quantity of the displacement means are selected such that, in the case of a, in particular substantially complete, gas extraction, in particular fuel extraction, from the gas storage volume the displacer volume and the separation element essentially all the volume available inside the gas container taking.

For example, the type and quantity of the displacement means can be selected such that in the case of a maximum gas filling, in particular fuel filling, the gas storage volume more than 90 vol .-%, for example more than 97 vol .-%, and / or the displacer volume less than 10 vol .-%, for example, less than 3 vol .-%, occupies the total available inside the gas container volume.

Another object of the present invention is a mobile, optionally portable, or stationary energy conversion system, which comprises a gas storage device according to the invention, in particular fuel gas storage, and / or performs a method according to the invention.

In the context of the present invention, an energy conversion system can be understood in particular to mean a device which comprises an energy converter which is designed to convert chemical energy into mechanical and / or electrical energy. In particular, an energy conversion system in the sense of the present invention can be understood as meaning a fuel cell system or an internal combustion engine, for example a hydrogen fuel cell, a hydrogen combustion engine, a natural gas fuel cell or a natural gas internal combustion engine. In particular, the energy conversion system may be a fuel cell system.

The energy conversion system according to the invention can advantageously be used for supplying energy to a vehicle, a building or a technical installation, for example a production plant or information technology installation, for example for the emergency power supply of a telecommunications system or a data center.

Furthermore, the present invention relates to a vehicle, a building or a technical installation which comprises a gas storage device according to the invention, in particular fuel gas storage, and / or carries out a method according to the invention and / or comprises an energy conversion system according to the invention.

Drawings and examples

Further advantages and advantageous embodiments of the subject invention are illustrated by the drawings and explained in the following description. It should be noted that the drawings have only descriptive character and are not intended to limit the invention in any way. Show it

1a . 1b show schematic cross sections to illustrate the operation of a first embodiment of a gas storage device according to the invention, in particular fuel gas storage with a membrane-shaped separating element;

2a . 2 B show schematic cross sections to illustrate the operation of a second embodiment of a gas storage device according to the invention, in particular fuel gas storage with a designed as a displaceable wall element partition member;

3 shows the phase diagram of carbon dioxide; and

4 shows a graph illustrating the usable storage capacity of an inventive and a conventional gas storage, in particular fuel gas storage.

The 1a and 1b such as 2a and 2 B illustrate the positive displacement principle of the gas storage device according to the invention, in particular fuel gas storage. The figures show that the gas storage in the case of both embodiments shown a gas tank 1 having a gas storage volume, in particular fuel storage volume, 2 and a displacer volume 3 includes. It is between the gas storage volume 2 and the displacer volume 3 a, in particular movable, separating element 4 arranged. Here are the size of the gas storage volume 2 and the size of the displacer volume 3 under a change in position of the separating element 4 variable. Since the gas storage volume 2 and the displacer volume 3 essentially, that is apart from the small volume which the separating element 4 occupies that inside the gas container 1 Divide available volumes, thereby changing the size of the gas storage volume 2 reciprocal to the size of the displacer volume 3 , The figures further show that the gas container 1 a designed as a valve, in particular openable and closable, gas inlet and / or outlet 5 for gas extraction and / or gas filling, in particular fuel extraction and / or fuel filling, of the gas storage volume 2 having. The gas storage volume 2 is designed in particular for receiving natural gas and / or hydrogen.

According to the invention is the displacer means volume 3 for receiving a displacer means, which under the operating conditions within the displacer volume 3 performs a liquid / gaseous or solid / gas phase change designed. In other words, it is crucial for the choice of the displacement means that this undergoes a phase change and thus a sudden change in density during an operating cycle. By compressing the displacer means and concomitant liquefaction of the displacer means, the volume of the displacer means can be reduced, thus increasing the volume available to the gas or fuel. In the typical operating conditions of an automotive gas container, this phase change can be carried out, for example, between 20 and 100 bar and -40 ° C to 85 ° C. Means which fulfill these conditions are, for example, carbon dioxide (CO ₂ ) and krypton (Kr). However, the principle according to the invention extends to any means which has the properties according to the invention. For carbon dioxide speaks in particular that this is safe and cheap to procure.

The 1a and 2a illustrate that in the case of a maximum gas filling, in particular fuel filling, the gas storage volume 2 more than 90 vol .-% and the displacer volume 3 occupy less than 10 vol .-% of the total available inside the gas container volume. The displacer is in the displacer volume 3 at least partially, optionally substantially completely, in liquid form.

The 1b and 2 B exemplify the variable size of the internal displacement volume 3 and show that the actual gas storage volume 2 was almost completely expelled. The 1b and 2 B illustrate in particular that at a gas extraction, in particular fuel extraction, the gas storage volume 2 downsized and alike that displacer volume 3 increased. In the case of one in the 1b and 2 B shown, substantially complete gas extraction, in particular fuel extraction, from the gas storage volume 2 take the displacer volume 3 and the separator 4 essentially the entire inside of the gas container 1 available volumes. Between in the 1a and 2a on the one hand shown state and in the 1b and 2 B On the other hand shown state, the displacer has at least partially, possibly substantially completely, completed a phase change from a liquid to a gaseous phase and thereby significantly increased its volume, in particular with a sudden decrease in density. Due to this effect can with the gas storage according to the invention even with a substantially complete gas removal from the gas storage volume 2 , an internal pressure within the gas container 1 , in particular within the gas storage volume 2 and within the displacer volume 3 , be achieved by ≥ 2 bar, in particular ≥ 20 bar. Thus, advantageously, the storage capacity of the gas container 1 be better exploited and penetration of impurities in the interior of the gas tank 1 be prevented in the emptied state.

The in the 1a and 1b The first embodiment shown differs essentially from that in the 2a and 2 B shown embodiment that the separating element 4 in the first embodiment, an elastically stretchable, in particular gas-tight, membrane and in the second embodiment is a displaceable wall element.

The 1a and 1b also illustrate that both the gas tank 1 as well as the separating element 4 is formed in the context of this embodiment as a self-contained hollow body, which has no permanently open openings. In this case, the separating element hollow body 4 within the gas container hollow body 1 arranged. In this case, both the gas container hollow body 1 as well as the separator hollow body 4 a valve 5 . 6 on, being the valve of the gas container 1 as a gas inlet and outlet and the valve of the separator hollow body 4 for filling the displacement means volume 3 with displacer serves. The 1a and 1b in particular, illustrate that of the separator hollow body 4 within the gas container hollow body 1 is formed bubble- or balloon-shaped, wherein the wall of the separating element hollow body 4 is formed of an elastically stretchable material and as a separating element 4 , in particular in the form of an elastically extensible membrane, wherein the internal volume of the separating element hollow body 4 as a displacer volume 3 serves.

The 1a to 2 B further illustrate that the gas reservoir according to the invention is a displacer reservoir 7 may have, which fluidly with the displacer means volume 3 connected is. The displacer reservoir 7 may be particularly adapted to receive the displacer in liquid or solid form. Thus, the maximum available for gas storage volume can advantageously be further increased. Since the displacer means at an increase in the gas storage volume 2 , in particular when filling the gas storage volume 2 , is displaced, it is possible this - as shown in the figures - to arrange in an elevated position. Of course, it is also possible to exploit gravity and the displacer reservoir 7 in a lower position, for example at the bottom of the gas container 1 form and / or arrange (not shown). As in the 1a to 2 B can be shown, the displacement medium reservoir 7 with the displacer inlet valve 6 be provided.

To illustrate the phase change-based displacement principle according to the invention is described in 3 reproduced the phase diagram of carbon dioxide. The critical temperature is T _k , the triple point T ₃ , the boiling point T _s , the solid phase s, the liquid phase l and the gaseous phase g. It can be seen that carbon dioxide is liquefied at a refueling pressure of over 72.8 bar (critical point). Along the evaporation curve then takes place the phase change. The sublimation curve up to the triple point can be neglected, as temperatures in the automotive field are usually above -57 ° C. The area of the supercritical fluid above the critical point T _k is also harmless, since the supercritical fluid and the normal fluid are comparable in their density. The arrow at 298.15 K illustrates an operating curve, which could be passed through when emptying the gas storage, in particular fuel gas storage.

4 illustrates the storage capacity of a conventional gas storage and a gas storage according to the invention during an operating cycle at 20 ° C and in a pressure range of 20 bar to 100 bar based on methane 8th as fuel gas and the change in the gas storage volume contained in the gas storage device according to the invention (methane) 9 and displacer volume (carbon dioxide) 10 during gas extraction or filling. 4 illustrates in particular that on the amount of displacer (carbon dioxide), the residual pressure in the gas can be easily adjusted.

For the 4 Underlying example calculation was a gas tank volume of 100 liters and assumed an ideal gas behavior. The inventive principle is illustrated by the following example: To completely fill a gas container volume of 100 liters at 20 ° C with a pressure of 20 bar with carbon dioxide, about 3.6 kg of carbon dioxide are needed. At 200 bar, 3.6 kg of carbon dioxide, which is liquid under these conditions, occupy a volume of 3.1 liters. Without carbon dioxide could be stored in a volume of 100 liters at 200 bar 13.13 kg of methane. At a residual pressure of 20 bar, however, 1.3 kg of methane would remain in a conventional gas storage. By a carbon dioxide amount of 3.6 kg, the maximum storable methane amount would indeed reduced by 0.4 kg to 12.73 kg in a gas storage tank according to the invention with a gas tank volume of 100 liters, but the methane can be substantially completely removed. On a residual amount of methane to maintain a residual pressure of 20 bar of 1.3 kg can therefore be dispensed with a gas storage device according to the invention. In this case, the additional removable 1.3 kg of methane, a reduction of the maximum storable methane amount by more than 0.4 kg, so that a total of a gas storage according to the invention may have a 0.9 kg higher methane storage capacity than an analog conventional gas storage without displacement means volume.

4 shows in particular that at 70 bar, a phase change occurs, which is accompanied by a sudden change in density. When the gas is removed, in particular fuel extraction, the gas container pressure remains at these 70 bar longer, until the displacer is completely evaporated.

QUOTES INCLUDE IN THE DESCRIPTION

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Cited patent literature

• DE 102004063071 A1 [0006]

Claims (15)

Gas storage, in particular fuel gas storage, in particular for a mobile or stationary energy conversion system; comprising a gas container, in particular a compressed gas container, wherein the gas container ( 1 ) - a gas storage volume, in particular fuel storage volume ( 2 ), - a displacer volume ( 3 ), - between the gas storage volume ( 2 ) and the displacer volume ( 3 ) arranged separating element ( 4 ) and - a gas inlet and / or outlet ( 5 ) for gas extraction and / or gas filling of the gas storage volume, in particular a fuel inlet and / or outlet ( 5 ) for fuel extraction and / or gas filling, in particular fuel filling, of the fuel storage volume ( 2 ), wherein the size of the gas storage volume ( 2 ) and the size of the displacer volume ( 3 ) under a change in position of the separating element ( 4 ) are variable, wherein the size of the gas storage volume ( 2 ) reciprocally to the size of the displacer volume ( 3 ), wherein the displacer volume ( 3 ) for receiving a displacement means, which under the operating conditions within the displacer volume ( 3 ) performs a liquid / gaseous or solid / gas phase change, is designed. Gas store according to claim 1, wherein the gas reservoir is a displacer inlet valve ( 6 ) for filling the displacer volume ( 3 ) with displacer. Gas storage according to claim 1 or 2, wherein the gas container ( 1 ) is a high pressure gas container. Gas storage according to one of claims 1 to 3, wherein in the case of, in particular substantially complete, gas removal, in particular fuel extraction, from the gas storage volume ( 2 ) is within the displacer volume volume, a pressure of ≥ 2 bar. Gas storage according to one of claims 1 to 4, wherein in the case of, in particular substantially complete, gas removal, in particular fuel extraction, from the gas storage volume ( 2 ) the displacer volume ( 3 ) and the separating element ( 4 ) substantially all of the interior of the gas container ( 1 ) occupy available volumes. Gas accumulator according to one of claims 1 to 5, wherein the displacer within a pressure range of ≥ 2 bar to ≤ 800 bar, for example from ≥ 20 bar to ≤ 100 bar, and within a temperature range of ≥ -40 ° C to ≤ 85 ° C, especially from ≥ -40 ° C to ≤ 50 ° C, a liquid / gaseous or solid / gaseous phase change takes place. Gas store according to one of claims 1 to 6, wherein the displacer comprises or is carbon dioxide (CO ₂ ) and / or krypton (Kr), in particular carbon dioxide. Gas storage according to one of claims 1 to 7, wherein the separating element ( 4 ) is an elastically extensible, in particular gas-tight, membrane, in particular wherein inside the gas container ( 1 ) is arranged in a self-contained, in particular bubble or balloon-shaped hollow body with a wall of an elastically extensible material, wherein the wall serves as a separating element and the inner volume as Verdrängermittelvolumen. Gas storage according to one of claims 1 to 8, wherein the separating element ( 4 ) is a displaceable wall element. Gas store according to one of claims 1 to 9, wherein the gas storage a Verdrängermittelreservoir ( 7 ), wherein the displacer reservoir ( 7 ) fluidically with the displacer volume ( 3 ) connected is. Gas storage according to one of claims 1 to 10, wherein the gas storage volume ( 2 ) is designed to absorb natural gas and / or hydrogen. Operating method for a gas storage, in particular fuel gas storage, according to one of claims 1 to 11, comprising the method steps: - filling the gas storage volume, in particular fuel storage volume, ( 2 ) with the gas, in particular fuel; and - filling the displacer volume ( 3 ) with the displacement means, wherein the type and quantity of the displacement means is selected such that the displacement means, in the case of a maximum gas filling, in particular fuel filling, of the gas storage volume ( 2 ) in the displacer volume ( 3 ) is at least partially, optionally substantially completely, in liquid or solid form and in the case of a, in particular substantially complete, gas removal, in particular fuel extraction, from the gas storage volume ( 2 ) in the displacer volume ( 3 ) is at least partially, optionally substantially completely, in gaseous form. Operating method according to claim 12, wherein the type and amount of the displacement means is selected such that in the case of a, in particular substantially complete, gas extraction, in particular fuel extraction, from the gas storage volume ( 2 ) - within the volume of displacement ( 3 ) is a pressure of ≥ 2 bar, in particular of ≥ 20 bar, is present, and / or - the displacer means volume ( 3 ) and the separating element ( 4 ) substantially all of the interior of the gas container ( 1 ) occupy available volumes. Mobile or stationary energy conversion system, for example fuel cell system, in particular for a vehicle, a building or a technical installation, comprising a gas storage, in particular fuel gas storage, according to one of claims 1 to 11 and / or performing a method according to claim 12 or 13. Vehicle, building or technical installation, comprising a gas storage, in particular fuel gas storage, according to one of claims 1 to 11 and / or carrying out a method according to claim 12 or 13 and / or comprising an energy conversion system according to claim 14.

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