DE102020113094A1 - Energy supply system for a motor vehicle and method - Google Patents

Abstract

According to the invention, the technology disclosed here relates to an energy supply system 5 for a motor vehicle, which has at least one consumer 40 for gaseous fuel and at least one supply line 20. By means of a pressure equalization tank 100, which is connected to the supply line 20 or to the consumer 40, the reaction to temperature increases is significantly improved. According to the invention, the technology disclosed here also relates to an associated method.

Description

The technology disclosed here relates to an energy supply system for a motor vehicle and an associated method.

Energy supply systems can be used, for example, to convert gaseous fuel into a form of energy that can be used by a motor vehicle. For this purpose, an energy supply system typically has a consumer for gaseous fuel, such a consumer being, for example, a fuel cell or a gas-operated internal combustion engine. In the case of a fuel cell, electrical energy is first generated from the gaseous fuel, which can then, for example, supply an electric motor that drives the motor vehicle. If a gas-powered internal combustion engine is used, it can be used directly to drive the motor vehicle. To supply the consumer for gaseous fuel, an energy supply system typically has at least one feed line for gaseous fuel, which is fluidically connected to the consumer. Such a supply line can, for example, be connected to one or more pressure vessels opposite the consumer, wherein gaseous fuel can be stored in these pressure vessels.

It has been shown that a pressure of the gaseous fuel can rise significantly in such a supply line while a motor vehicle is parked. This can be done, for example, when the motor vehicle is parked at a cold temperature and warms up while parking. Here, for example, the case may arise that in an area under consideration between a pressure regulator and the consumer, the pressure regulator is closed upstream and a shut-off valve of the consumer is also closed downstream. If the temperature now increases, the pressure in the area under consideration can increase to such an extent that, for example, a pressure relief valve opens and a certain amount of gaseous fuel is blown into the environment.

It is a preferred object of the technology disclosed here to reduce or remedy at least one disadvantage of a previously known solution or to propose an alternative solution. In particular, it is a preferred object of the technology disclosed here to provide an energy supply system for a motor vehicle which can react better to a temperature increase when parking. Further preferred objects can result from the advantageous effects of the technology disclosed here. The objects are achieved by the subject matter of the independent claims. The dependent claims represent preferred configurations.

The technology disclosed here relates to a power supply system for a motor vehicle. The energy supply system has (i) at least one consumer for gaseous fuel, (ii) at least one feed line for gaseous fuel, which is fluidically connected to the consumer, and (iii) at least one pressure equalization tank which has an inlet that is connected to the feed line or is fluidically connected to the consumer. The pressure equalization container has a fluidically separate equalization volume which is under counter pressure and is coupled to a pressure applied at the inlet via a fluid-tight separating element. The separating element can be moved to a limited extent in the pressure compensation tank.

Such a power supply system makes it possible to react to a possible increase in temperature and an associated pressure increase by moving the fluid-tight separating element in the pressure equalization container and thus a larger space is available for gas that increases in pressure. The pressure increase can thus be significantly reduced and the opening of pressure relief valves can be avoided.

The energy supply system can in particular be designed to provide a form of energy that can be used by the motor vehicle. This can be electrical energy, for example, if the gaseous consumer is a fuel cell, or it can be kinetic energy if the gaseous consumer is a gas-powered internal combustion engine. The technology disclosed here can be used advantageously in both cases.

The gaseous consumer can in particular be supplied with the gaseous fuel via the supply line. This can be, for example, hydrogen, natural gas or another gaseous fuel. The supply line is fluidically connected to the consumer, which means in particular that a fuel flowing through the supply line reaches the consumer.

As already mentioned, the pressure equalization tank is used in particular to keep an additional volume ready, into which an enclosed gas can expand in order to avoid draining via pressure relief valves. The inlet of the pressure equalization tank is typically an area at which the pressure equalization tank is attached to the supply line or to the consumer or a line connected to it connected. The term input is not to be understood to mean that only gas can flow into the pressure compensation tank. Rather, the inlet is to be understood as a connection to further components, with gas also being able to flow out of the pressure equalization container at the inlet.

When the inlet is connected to the supply line, for example, an area outside the consumer or an area protruding into the consumer can be connected to the pressure equalization tank, which can experience a pressure increase when it is appropriately disconnected. For example, this can be an area of the supply line between a pressure regulator mentioned below and a shut-off valve of the consumer. However, the input can also be connected to the consumer, so that it can be connected to a line within the consumer, for example, and can perform the corresponding functionality there.

A fluidically separate compensation volume should be understood to mean, in particular, that any gas exchange between the fluidically separate compensation volume and the inlet of the pressure compensation tank is prevented. This means that gas molecules, possibly apart from unavoidable diffusion processes, are not exchanged between the inlet and the compensation volume. The pressure compensation tank is designed accordingly to be mechanical. The counterpressure is in particular a pressure which can act on a gas present at the inlet from the compensation volume. The counterpressure can in particular be an idle pressure of the compensating volume, this counterpressure typically ensuring that the separating element is kept in a rest position in typical operating situations, such as for example during operation of the consumer. For this purpose, the counter pressure can, for example, be at least 1 bar, at least 2 bar and / or at most 3 bar or at most 4 bar, or also 2.5 bar, above a maximum pressure of a fluid volume or pressure range connected to the inlet. When using a pressure reducer, for example, the maximum pressure can be that pressure from which the pressure reducer shuts off a pressure area of the supply line connected to the inlet opposite to the consumer.

The fluid-tight separating element can in particular be designed to be fluid-tight in such a way that it prevents gas exchange between the inlet and the compensation volume. This can apply in particular apart from any unavoidable diffusion. The complete fluidic separation of the compensating volume is achieved in that, in addition to the separating element, other components are also designed in a correspondingly fluid-tight manner, for example those which are mentioned below, and that these components are connected to one another in a fluid-tight manner.

Coupling the equalizing volume to the pressure applied at the inlet is understood to mean, in particular, that the counter pressure can act on the gas volume enclosed at the inlet or its pressure, at least in certain situations. This does not mean that this effect always has to be present. In particular, it can be provided that the separating element is pressed into a rest position by the counterpressure in a normal operating state and the counterpressure has no influence on the pressure applied at the inlet. Only when the pressure applied at the inlet becomes greater than the counter pressure does the separating element move, possibly together with other components, and the counter pressure then acts on the pressure applied at the inlet or the connected gas volume. As a result of the movement of the separating element, the compensation volume is basically reduced, so that a larger volume is available for the gas volume connected to the inlet. The pressure increase there is thus reduced and an opening of pressure relief valves, which could lead to the discharge of gas, is avoided.

Limited mobility of the separating element is to be understood in particular as meaning that the separating element can move along a certain path in the pressure equalization tank and thereby changes the division of the pressure equalization tank between equalization volume and further volume within the pressure equalization tank. In particular, the separating element can be displaced in response to a pressure applied at the inlet which is higher than the counterpressure, so that the equalization volume is reduced and thus the volume of the pressure equalization tank that is not the equalization volume is increased. The mobility of the separating element can be limited in particular by stops or other components such as the flexible element, for example, so that the separating element typically cannot move completely freely in the pressure compensation tank.

According to a preferred embodiment, the pressure compensation container has a fluid-tight, flexible element which is fastened in a fluid-tight manner in the pressure compensation container. The separating element is preferably attached to the flexible element in a fluid-tight manner. The fluid-tight design of the flexible element prevents gas exchange between the inlet and the equalization volume through this flexible element. This, too, can in particular be understood apart from an unavoidable diffusion. The fluid-tight fastenings of the flexible element in the pressure equalization container and the separating element on the flexible element, gas exchange between the inlet and the equalization volume is also prevented. The flexible element can in particular ensure that the separating element has the limited mobility already mentioned and at the same time the fluid-tightness between the inlet and the compensation volume is maintained. The flexible element can in particular experience a deformation when the separating element moves in the pressure compensation tank.

The flexible element can in particular be a bellows. Such a bellows can in particular be designed in that it has a plurality of lamellae which can be moved to a limited extent relative to one another. Such lamellae can typically be more rigid than connections between the lamellae, so that essentially connections between the lamellae experience a deformation when the flexible element is to show its flexibility, i.e. for example when the separating element moves in the pressure compensation tank. The flexible element is thus in particular an element which can be adapted in terms of shape to changing circumstances. It is typically at least partially flexible, but can also contain more solid or solid components.

The lamellas can in particular be elements which can in particular be smaller than the separating element and, for example, can lie close to one another in a state of rest, but can also be tilted towards one another or further apart in another state.

The flexible element can in particular be fastened in a fluid-tight manner to a fluid-tight holder. The fluid-tight holder can in particular be attached to a wall and / or to one or two container components of the pressure compensation container. The holder can in particular be welded to the wall.

The separating element preferably has a rest position. Such a rest position can in particular be provided by a suitable structuring of components within the pressure compensation tank, with the separating element typically being pressed into the rest position by the counterpressure in the compensation volume. This is particularly the case as long as the pressure at the inlet of the pressure compensation tank is lower than the counterpressure. In this case, the counterpressure ensures that the compensating volume and the counterpressure contained therein have no or at least no significant influence on the pressure applied at the inlet, so that the compensatory volume only becomes relevant if the pressure applied at the inlet rises above the counterpressure . In this case, in particular the volume of the pressure equalization tank that is available outside the equalization volume can then be increased, which achieves the advantageous effects already mentioned. Pressing the separating element into the rest position by the counter pressure prevents it from constantly moving during normal operation of the energy supply system, which could lead to wear and an undesirable influence on the gas supply.

According to an advantageous embodiment, the energy supply system has a pressure reducer which divides the supply line into a first pressure area and a second pressure area, the second pressure area being connected to the consumer and the inlet of the pressure compensation tank being connected to the second pressure area. The first pressure area is in particular arranged upstream of the second pressure area and thus also upstream of the consumer. The first pressure area can in particular be connected to one or more pressure vessels, which will be mentioned in more detail below. By connecting the inlet of the pressure equalization tank to the second pressure area, this second pressure area is provided with the functionality already described above, namely that an increase in temperature can be responded to by increasing the volume available in the pressure equalization tank by moving the separating element is provided. For example, in a typical parking situation of the motor vehicle, both the pressure compensation tank and a shut-off valve of the consumer can be closed so that the second pressure area of the supply line is shut off in both the upstream and downstream directions. In the case of embodiments according to the prior art, if the pressure increases due to temperature, gas would be released through an overpressure valve. As already described, this can be prevented by the technology disclosed here.

Alternatively, the input can also be connected to the first pressure area, whereby this pressure area can also be provided with the functionality described. In principle, it is also possible to use a plurality of pressure compensation tanks on an energy supply system, which can in particular be designed as described herein and can achieve the functionality described herein at their respective point to which they are connected.

The first pressure area can in particular be a high pressure area and the second pressure area can in particular be a medium pressure area. The first pressure area or a high pressure area can in particular be designed for a pressure of several hundred bar, for example at least 350 bar or at least 700 bar. A medium pressure range can be designed for a pressure of a maximum of 50 bar, for example. However, other pressures are also possible here.

The energy supply system can in particular have one or more pressure vessels for storing the gaseous fuel, the pressure vessel or vessels typically being connected to the supply line opposite the consumer. In particular, they can be connected to a high pressure area, as already mentioned above. The consumer can be supplied with gaseous fuel such as hydrogen or natural gas from such pressure vessels. The connection of the pressure vessel or the pressure vessel can take place, for example, directly or via other components such as valves or distribution lines.

The pressure equalization container can in particular have an opening which is fluidically connected to the equalization volume. The opening can be closed with a stopper and / or a valve. This means that the compensation volume can be filled or gas can also be withdrawn.

The consumer already mentioned above is set up in particular to convert the chemical energy of the fuel into other forms of energy, for example into electrical energy and / or into kinetic energy. The consumer can be, for example, an internal combustion engine, for example a gas-powered internal combustion engine, or a fuel cell system or fuel cell stack with at least one fuel cell. In its simplest form, a fuel cell is an electrochemical energy converter that converts fuel (e.g. hydrogen) and oxidizing agents (e.g. air, oxygen and peroxides) into reaction products, thereby producing electricity and heat.

A fuel cell can provide electrical energy to the motor vehicle, for example, in that the fuel cell feeds the electrical energy obtained through an electrochemical reaction in the fuel cell or in the fuel cell stack into the vehicle electrical system, for example via appropriate current collectors and possibly via any voltage converters. The fed-in energy is converted into other forms of energy by the electrical consumers (usually the electrical drive machine and any auxiliary consumers) of the on-board network, or it is stored in at least one electrical energy storage device.

Pressure vessels are used in particular to store fuel that is gaseous under ambient conditions. The technology disclosed here can be used, for example, in a motor vehicle that is operated with compressed (also called compressed natural gas or CNG) or liquefied (also called liquid natural gas or LNG) natural gas or with hydrogen. Such gaseous fuels can, for example, be converted into other forms of energy by the consumer.

A pressure vessel can in particular be designed as a composite overwrapped pressure vessel. The pressure vessel can be, for example, a cryogenic pressure vessel or a high-pressure gas vessel. High-pressure gas containers are designed to store fuel permanently at ambient temperatures at a nominal operating pressure (also called nominal working pressure or NWP) of at least 350 barg (= overpressure compared to atmospheric pressure) or at least 700 barg. A cryogenic pressure vessel is suitable for storing the fuel at the aforementioned operating pressures even at temperatures that are significantly (for example more than 50 K or more than 100 K) below the operating temperature of the motor vehicle.

The pressure reducer already mentioned above is arranged in particular downstream of the at least one pressure vessel and upstream of the consumer. The pressure reducer is typically designed to reduce the fuel inlet pressure applied at the inlet of the pressure reducer to a fuel outlet pressure or back pressure applied at the outlet of the pressure reducer. In its simplest form, it can be a throttle. As a rule, the pressure reducer includes a pressure reducing valve which, despite different inlet pressures, ensures that a certain outlet pressure is not exceeded on the outlet side. The fuel expands in the pressure reducer.

The technology disclosed here also relates to a method for manufacturing a pressure equalizing container. The pressure compensation tank can be used in particular in a power supply system disclosed herein.

• - fluiddichtes Befestigen eines fluiddichten flexiblen Elements an einer fluiddichten Halterung,
• - fluiddichtes Befestigen eines fluiddichten Trennelements an dem flexiblen Element,
• - Einbringen der Halterung in eine erste Behälterkomponente oder eine zweite Behälterkomponente, wobei in der ersten Behälterkomponente eine Öffnung ausgebildet ist und in der zweiten Behälterkomponente ein Eingang ausgebildet ist,
• - Zusammenführen der ersten Behälterkomponente und der zweiten Behälterkom ponente,
• - fluiddichtes Befestigen der Halterung an mindestens einer der Behälterkom ponenten,
• - fluiddichtes Befestigen der zweiten Behälterkomponente an der ersten Behälterkomponente, wobei bezüglich des Trennelements gegenüberliegend zum Eingang ein fluidisch separates Ausgleichsvolumen gebildet wird,
• - Befüllen des Ausgleichsvolumens mit einem Gas durch die Öffnung, so dass dieses einen Gegendruck im Ausgleichsvolumen hat, und
• - Verschließen der Öffnung.

The procedure consists of the following steps:

• - fluid-tight fastening of a fluid-tight flexible element to a fluid-tight holder,
• - fluid-tight fastening of a fluid-tight separating element to the flexible element,
• - Introducing the holder into a first container component or a second container component, an opening being formed in the first container component and an inlet being formed in the second container component,
• - Merging the first container component and the second container component,
• - fluid-tight fastening of the bracket to at least one of the container components,
• - fluid-tight fastening of the second container component to the first container component, a fluidically separate compensating volume being formed with respect to the separating element opposite the inlet,
• - Filling the compensation volume with a gas through the opening so that it has a counter pressure in the compensation volume, and
• - Closing the opening.

By means of such a method, a pressure compensation tank, which can be used, for example, in the energy supply system described above, can be produced in an efficient and advantageous manner.

As far as applicable, device aspects described herein can also be used in the context of the method. The same applies in the opposite direction.

A fluid-tight fastening is understood to mean, in particular, that the elements to be fastened to one another are connected to one another in such a way that no gas can pass through along the connection point either. This can in particular be the case except for an unavoidable diffusion.

A fluid-tight holder is in particular an element which is attached to a container component and to which the flexible element is attached. The fluid-tight design of the fluid-tight holder ensures that, as already mentioned, no gas exchange takes place through the fluid-tight holder, that is, it forms a partial barrier against gas exchange inside the pressure equalization tank to be produced. The same applies to the flexible element and the separating element.

The two container components are in particular components which, after being brought together and fastened in a fluid-tight manner, together essentially form an external shape of the pressure compensation container. Instead of the term container component, the term pressure compensation container component can also be used here, the term container component being used because it is shorter.

The opening and the entrance can in principle be designed as passages in the respective container component. The terms are especially used to distinguish the two passages from one another. In the finished pressure equalization container, the opening is typically connected to the equalization volume and can serve to fill the equalization volume with a pressurized gas or to let it out again. In particular, the input can later be connected to further components of the energy supply system, for example as described above.

The holder can in particular be attached to the first container component or to the second container component. It can also be attached to both container components at the same time, for example as will be described in more detail below.

The equalization volume can act like a gas spring in the finished pressure equalization tank, for example. In this way it differs from an opposite volume, which is directly connected to the inlet, on which such an effect occurs.

Nitrogen, for example, can be used as the gas for filling. Another gas or a mixture of other gases can also be used for this purpose. In particular, the pressures already mentioned above can be set.

The closure of the opening can in particular be a permanent closure or also the closure with a valve, which enables gas to be introduced and / or withdrawn several times. This is discussed in more detail below.

In particular, a bellows can be used as the flexible element. This can, for example, be made from the lamellae already mentioned above. Reference is made to the above explanations in this regard.

The fastening of the holder and the fastening of the second container component to the first container component can in particular take place by welding. This has proven to be an advantageous type of connection for this purpose. The welding enables a fluid-tight and permanent connection, which with suitable designs easily withstands the expected pressures.

When the holder is fastened, it can be arranged in particular on a contact area between the first container component and the second container component. In other words, for example, a partial area of the holder can extend along both container components or their contact area. The container components typically abut at the contact area. As a result, the first container component can be welded to the second container component in a particularly advantageous manner, for example with a weld seam, and by arranging the holder as just described, it can extend along the weld seam so that it can also be attached by this weld seam. The fastening of the holder and the fastening of the second container component to the first container component can in particular take place in one operation. This saves time and effort. In particular, this can take place if, as already described, the holder is arranged during attachment to a contact area between the first container component and the second container component.

The opening can be closed in particular with a stopper and / or with a valve. This can be, for example, a check valve, the flow direction of which points towards the compensation volume. However, another valve can also be used for this purpose, it being possible, for example, to only introduce gas by means of a check valve, and also to withdraw gas by means of another valve. A stopper can, for example, completely close the opening so that a one-time filling remains in the compensation volume forever, or it can also be removably attached so that the gas contained can also be exchanged or withdrawn later.

The technology disclosed herein further relates to a pressure equalization container that was manufactured by means of a method disclosed herein. With regard to the method, all of the variants described can be used.

In other words, it was recognized that, for example, in a medium-pressure area of hydrogen tank systems, the pressure can rise sharply during parking. This can happen if the vehicle is parked in a cold temperature and warms up while parking. For example, hydrogen is trapped in the medium pressure range during parking. A pressure regulator upstream is closed and a shut-off valve of a fuel cell arranged downstream, for example, which can represent a consumer, is also closed. If the temperature rises during parking from, for example, -20 ° C to, for example, + 20 ° C, then the pressure in the medium pressure range also rises. This can go so far that pressure relief valves open and a certain amount of hydrogen is blown off into the environment.

In order to avoid this, a pressure equalization tank can be used, for example, as described herein.

• - Membranbalg mit Topf verschweißen,
• - Membranbalg mit Topf an Deckel schweißen,
• - Membranbalg in Behälter-Oberteil stecken,
• - Behälter-Unterteil aufsetzen,
• - äußere Schweißnaht verbindet Behälter-Teile und Topf,
• - Montieren des Stopfens,
• - Montieren des Klima-Ventileinsatzes,
• - Füllen der zweiten Kammer mit Stickstoff oder einem anderen Gas (zum Beispiel Wasserstoff, CO₂, Argon, Helium, Formiergas) auf festgelegten Überdruck,
• - Aufsetzen der Staubschutzkappe.

Production and assembly on the tank system can take place as follows, for example:

• - Weld the diaphragm bellows to the pot,
• - Weld the diaphragm bellows with the pot to the cover,
• - Insert the diaphragm bellows in the upper part of the container,
• - Put on the lower part of the container,
• - outer weld seam connects container parts and pot,
• - assembling the plug,
• - Assembling the air conditioning valve insert,
• - Filling the second chamber with nitrogen or another gas (e.g. hydrogen, CO ₂ , argon, helium, forming gas) to a specified overpressure,
• - Put on the dust cap.

For example, if the pressure in the medium pressure range increases, this can lead to a pressure difference between the medium pressure range and a volume filled with nitrogen. The diaphragm bellows is deformed in the process. The tank volume connected to the medium pressure area is increased and the other is decreased. The final pressure when parking is therefore lower, because the hydrogen mass in the medium pressure range is distributed in a larger volume. In other words, at the same temperature, the hydrogen density is lower and so is the pressure.

The effect of the pressure equalization tank can be particularly effective because gaseous fuel flowing during normal operation typically has a significantly lower temperature than the surroundings due to expansion at the pressure tank. If, for example, the ambient temperature warms up during parking, the counterpressure present in the compensation volume also increases in principle, since a certain increase in temperature is to be expected here as well. However, the effect of the temperature increase is much more pronounced in the case of gaseous fuel, since, as just mentioned, this typically has a significantly lower temperature during normal operation. That's why the Pressure expansion tank can easily fulfill its functions described here even if it also heats up due to an increase in the ambient temperature during parking.

• 1: ein Energieversorgungssystem, und
• 2: einen Druckausgleichsbehälter.

The technology disclosed here will now be described with reference to the figures. Show:

• 1 : a power supply system, and
• 2 : an expansion tank.

1 shows purely schematically an energy supply system 5 for a motor vehicle. The energy supply system 5 has a pressure vessel 10 for gaseous fuel. It instructs a consumer 40 on, which can in particular be a gas-powered internal combustion engine or a fuel cell. The consumer 40 has a shut-off valve 45 on the inlet side. Between the pressure vessel 10 and the consumer 40 is a feed line 20th connected through which gaseous fuel from the pressure vessel 10 to the consumer 40 can be directed. The feed line 20th is through a pressure reducer 30th in a first pressure area 21 and a second printing area 22nd divided. The first print area 21 is a high pressure area, which is designed for a pressure of several hundred bar. The second print area 22nd is a medium pressure range, which is designed for a pressure of 50 bar, for example.

The energy supply system 5 has a pressure compensation tank 100 on. This is described in more detail below with reference to FIG 2 are described, however, are here in 1 the most important components are shown and described. The pressure compensation tank 100 has an entrance 110 on, which via a connecting line 23 at the second printing area 22nd the supply line 20th connected. So is at the entrance 110 basically the same pressure as that in the second pressure range 22nd prevails.

The pressure vessel 100 has an input volume 120 on at which the entrance 110 is connected and which thus also has the pressure applied at the inlet. Furthermore, the pressure compensation tank 100 a compensation volume 130 on which of the input volume 120 is completely separated fluidically. In other words, there is a gas exchange between the inlet volume 120 and the compensation volume 130 except for any unavoidable diffusion prevented.

Between the input volume 120 and the compensation volume 130 are in particular a separator 140 and a flexible element 150 educated. As below with reference to 2 Will be described in more detail below is the flexible element 150 designed as a bellows, whereby the separating element 140 limited mobility in the pressure compensation tank 100 is arranged. The compensation volume 130 is filled with a gas that is under a counter pressure that acts on the separating element 140 works. The separator 140 is due to the selected level of back pressure during normal operation of the energy supply system 5 typically pressed into a rest position in which the compensation volume 130 is maximum. Thus, the pressure basically has no effects on the operation of the energy supply system during this normal operation 5 .

If, however, the motor vehicle is now switched off, a certain amount of gas remains in the second pressure range 22nd locked up. Upstream is the then closed pressure reducer 30th arranged, downstream is the consumer 40 arranged, the shut-off valve 45 is then typically closed. If the temperature now increases, for example due to an adjustment of the typically lower gas temperature during the gas flow to the ambient temperature, or also due to an increase in the ambient temperature, the pressure in the second pressure range increases in principle due to the general gas equation 22nd . In the case of embodiments according to the prior art, this would typically lead to gas being released from at least a certain pressure threshold, for which purpose pressure relief valves are provided, for example. Excess gaseous fuel is then vented into the environment.

This can be avoided with the design shown here. As soon as the pressure in the second pressure area 22nd via the counter pressure in the compensation volume 130 increases, the separator moves 140 from a position of rest, in the representation of 1 up. This results in a pressure equalization between the inlet volume 120 and the compensation volume 130 without an exchange of gas at the same time. By moving the separator 140 this becomes the gas that is in the second pressure range 22nd is included, the available volume is increased and thus the pressure build-up already described is significantly reduced. Letting off gas can thus advantageously be avoided.

2 shows the pressure compensation tank 100 in greater detail, and how the expansion tank is also described below 100 can be produced.

The pressure compensation tank 100 is basically made of a first container component on the outside 160 and a second container component 170 composed. These are in front of you Manufacturing process is basically separate from each other and are brought together and connected to one another during manufacture. In the pressure equalization tank 100 there is a bracket 180 which, in the fully assembled state, has an outer section at a contact area as shown 182 between the two container components 160 , 170 is located. This enables simple production, as will be described in more detail below. The container components 160 , 170 together form a wall of the pressure compensation tank 100 .

The already mentioned separating element 140 is in the present case disc-shaped. It's on the flexible element 150 attached, the flexible element 150 is designed as a bellows with a plurality of lamellae 155. The lamellae 155 are designed to be movable with respect to one another, so that the flexible element 150 can basically expand and a removal of the separating element 140 from the bracket 180 allowed to the left. The in 2 The state shown thus represents a rest position of the separating element 140 represents what is taken when the separator is 140 is moved as far to the right as possible.

For production, the separating element 140 with the flexible element 150 be connected fluid-tight, and the flexible element 150 can with the bracket 180 be connected fluid-tight. All elements are also fluid-tight with one another, so that overall a fluid-tight separation in the pressure equalization tank 100 is produced. The corresponding with the separator 140 and the flexible element 150 connected bracket 180 can then in the first container component 160 are introduced, and the second container component 170 can be attached. The state shown can already be assumed. The first container component 160 , the second container component 170 and the bracket 180 can then by means of a single welding process with the formation of a weld bead 185 are connected to one another, a stable and fluid-tight design being achieved. The bracket 180 , the flexible element 150 and the separator 140 then subdivide the interior of the pressure compensation tank 100 into the input volume already mentioned 120 and the compensation volume already mentioned 130 .

In the first container component 160 is an opening 190 formed by a plug 192 is locked. On the stopper 192 is a valve 194 arranged through which the compensation volume 130 can be filled with a gas, which is filled in particular until a desired counter pressure is reached. The valve 194 can be designed as a non-return valve, so that only filling is possible, but it can also be designed as a normal valve with a flow option in both directions, so that gas can also be withdrawn. It is covered by a cover 196 covered.

The stopper 192 , the valve 194 and the cover 196 can before or after the described connection of the container components 160 , 170 and the bracket 180 be introduced.

The second container component 170 shows the already mentioned entrance as shown 110 in which the connecting line 23 flows out. This allows a connection to the rest of the energy supply system 5 can be produced, for example as in 1 and as described with respect to it.

In principle, the pressure compensation tank 100 alternatively also directly at the consumer 40 or also in the high pressure area 21 be connected. It is also possible in principle to use several such pressure vessels for different areas.

By using the pressure expansion tank 100 In comparison to known designs, the reaction to temperature increases can be significantly improved with a manageable effort, in particular an otherwise necessary discharge of gaseous fuel can be avoided.

For reasons of legibility, the expression “at least one” has been partially omitted for the sake of simplicity. If a feature of the technology disclosed here is described in the singular or indefinitely (e.g. the / a pressure vessel, the / a valve, etc.), the plurality of these should also be disclosed at the same time (e.g. the at least one pressure vessel, the at least one valve , Etc.).

The preceding description of the present invention is for illustrative purposes only and not for the purpose of limiting the invention. Various changes and modifications are possible within the scope of the invention without departing from the scope of the invention and its equivalents.

List of reference symbols

5:

Energy supply system

10:

pressure vessel

20:

supply line

21:

first printing area

22:

second pressure area

23:

Connecting line

30:

Pressure reducer

40:

consumer

100:

Pressure equalization tank

110:

entry

120:

Input volume

130:

Compensation volume

140:

Separator

150:

flexible element

160:

first container component

170:

second container component

180:

bracket

182:

Contact area

185:

Weld bead

190:

opening

192:

Plug

194:

Valve

196:

cover

Claims (15)

A power supply system (5) for a motor vehicle, comprising - at least one consumer (40) for gaseous fuel, - At least one feed line (20) for gaseous fuel, which is fluidically connected to the consumer (40), and - At least one pressure equalization tank (100) which has an inlet (110) which is fluidically connected to the supply line (20) or to the consumer (40), the pressure equalization tank (100) having a fluidically separate equalization volume (130) which is under a counterpressure and is coupled to a pressure applied to the inlet (110) via a fluid-tight separating element (140), and wherein the separating element (140) can be moved to a limited extent in the pressure compensation tank (100). Energy supply system (5) according to Claim 1 - wherein the pressure compensation container (100) has a fluid-tight flexible element (150) which is fastened in a fluid-tight manner in the pressure compensation container (100), and - wherein the separating element (140) is fastened to the flexible element in a fluid-tight manner. Energy supply system (5) according to Claim 2 wherein the flexible element (150) is a bellows. Energy supply system (5) according to Claim 3 , wherein the bellows has a plurality of lamellae (155) which can be moved to a limited extent relative to one another. Energy supply system (5) according to one of the preceding claims, wherein the separating element (140) has a rest position. Energy supply system (5) according to Claim 5 , wherein the separating element (140) is pressed into the rest position by the counterpressure, as long as a lower pressure than the counterpressure is present at the inlet (110) of the pressure compensation tank (100). Energy supply system (5) according to one of the preceding claims, wherein the energy supply system (5) has a pressure reducer (30) which divides the supply line (20) into a first pressure area (21) and a second pressure area (22), the second pressure area ( 22) is connected to the consumer (40) and the input (110) of the pressure compensation tank (100) is connected to the second pressure area (22). Energy supply system (5) according to Claim 7 wherein the first pressure area (21) is a high pressure area and the second pressure area (22) is a medium pressure area. Energy supply system (5) according to one of the preceding claims, wherein the energy supply system (5) has one or more pressure vessels (10) for storing the gaseous fuel, which is / are connected to the supply line (20) opposite to the consumer (40). A method for producing a pressure compensation container (100), which has the following steps: - fluid-tight fastening of a fluid-tight flexible element (150) to a fluid-tight holder (180), - fluid-tight fastening of a fluid-tight separating element (140) to the flexible element (150), - Introducing the holder (180) into a first container component (160) or a second container component (170), an opening (190) being formed in the first container component (160) and an inlet (110) being formed in the second container component (170) - Merging the first container component (160) and the second container component (170), - fluid-tight fastening of the holder (180) to at least one of the container components (160, 170), - fluid-tight fastening of the second container component (170) to the first container component (160), with a fluidically separate compensation volume (130 ) is formed, - Filling the compensation volume (130) with a gas through the opening (190) so that it has a counterpressure in the compensation volume (130), and - closing the opening (190). Procedure according to Claim 10 , wherein a bellows is used as the flexible element (150). Procedure according to Claim 10 or 11th wherein the fastening of the holder (180) and the fastening of the second container component (170) to the first container component (160) are carried out by welding. Method according to one of the Claims 10 until 12th wherein, when the holder (180) is being fastened, it is arranged on a contact area (182) between the first container component (160) and the second container component (170). Method according to one of the Claims 10 until 13th wherein the fastening of the holder (180) and the fastening of the second container component (170) to the first container component (160) take place in one operation. Method according to one of the Claims 10 until 14th , wherein the closure takes place with a stopper (192) and / or with a valve (194).

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