DE102017217348A1 - Pressure vessel system and method for supplying fuel from a pressure vessel system - Google Patents

Abstract

A pressure vessel system (10) for a vehicle is shown, wherein the pressure vessel system (10) comprises at least one cryogenic pressure vessel for storing fuel, in particular hydrogen, and at least one high-pressure gas vessel for storing fuel, in particular hydrogen an inlet of the cryogenic pressure vessel (20) via a connecting line (17) with a filling opening (15) for filling the cryogenic pressure vessel (20) is fluidly connected, wherein an outlet of the high pressure gas container (60) via a connecting line (65) with a fuel consumer (80 ), in particular a fuel cell, is fluid-connected, characterized in that in a first closable connection line (32) between the outlet of the cryogenic pressure vessel (20) and an inlet of the high-pressure gas container (60) is a compressor for compressing the fuel from the cryogenic pressure vessel (20 ) is arranged.

Description

The invention relates to a pressure vessel system for a vehicle and to a method for supplying fuel from a pressure vessel system to a fuel consumer.

In vehicles that are powered by hydrogen or a fuel cell, a pressure vessel system is usually arranged. The pressure vessel system often includes a cryogenic pressure vessel in which fuel, especially hydrogen, is mainly stored. Pressure vessel systems often include a cryogenic pressure vessel and a non-cryogenic pressure vessel.

If the pressure of the fuel in the cryogenic pressure vessel is too low, the fuel in the cryogenic pressure vessel is often heated, e.g. by means of a tank heat exchanger to increase the pressure of the fuel in the cryogenic pressure vessel.

A disadvantage of pressure vessel systems known hitherto is that, starting from an empty cryogenic pressure vessel warming the environment, the maximum possible storage density of fuel, in particular hydrogen, in the cryogenic pressure vessel can not be achieved during the first filling, but only e.g. after the fourth filling with fuel. This is because only then a low temperature or the lowest temperature in the cryogenic pressure vessel is achieved. Thus, the maximum possible storage mass or the maximum possible storage density of fuel in the cryogenic pressure vessel can only be achieved if the cryogenic pressure vessel is cold enough before filling. This also has the disadvantage that between the fillings of the pressure vessel system, the pressure vessel is not warmed up or heated by a tank heat exchanger, so it must be driven completely empty, otherwise the maximum storage density drops in the next filling.

In addition, it is disadvantageous that for substantially complete removal of fuel from the cryogenic pressure vessel of the cryogenic pressure vessel must be heated, otherwise the pressure of the fuel in the pressure vessel for supplying the fuel to a fuel consumer (eg, a fuel cell for driving the vehicle) or to a High pressure regulator before the fuel consumer is too low or below a limit, if a (large) part of the fuel has been removed from the cryogenic pressure vessel. A high-pressure regulator, which is arranged between the pressure vessel and the fuel consumer, regulates e.g. to a mean pressure of about 15 bar.

By heating, the pressure of the fuel in the cryogenic pressure vessel can be increased. However, heating the cryogenic pressure vessel to remove the fuel remaining in the cryogenic pressure vessel in turn means that the maximum fuel density in the pressure vessel is not reached in the next filling due to the elevated temperature. That the amount of fuel storable in the cryogenic pressure vessel decreases due to the heating to remove the fuel. As a result, the maximum range of the vehicle when refilling the pressure vessel system or the cryogenic pressure vessel is thus not achieved.

High-pressure gas containers or high-pressure gas container systems (also called "CGH2 systems") are designed to permanently store fuel at ambient temperatures at a pressure of about 350 bar (= overpressure relative to the atmospheric pressure), furthermore preferably above about 500 bar and especially preferably above save about 700 cash.

Cryogenic pressure vessel systems (also called "CcH2 systems") are known from the prior art. For example, the EP 1 546 601 B1 such a system.

It is a preferred object of the technology disclosed herein to reduce or eliminate at least some of the disadvantages of the previously known solutions. Other preferred objects may result from the beneficial effects of the technology disclosed herein. The object (s) is / are solved by the subject matter of patent claim 1 of the independent claims and the subject matter of claim 8 of the independent claims. The dependent claims are preferred embodiments.

In particular, the object is achieved by a pressure vessel system for a vehicle, the pressure vessel system comprising at least one cryogenic pressure vessel for storing fuel, in particular hydrogen, and at least one high-pressure gas vessel for storing fuel, in particular hydrogen, wherein an inlet of the cryogenic pressure vessel via a connecting line with a filling opening for filling the cryogenic pressure vessel is fluidly connected, wherein an outlet of the high pressure gas container via a connecting line with a fuel consumer, in particular a fuel cell, fluidly connected, characterized in that in a first closable connection line between the outlet of the cryogenic pressure vessel and an inlet of the high-pressure gas container, a compressor for compressing the fuel from the cryogenic pressure vessel is arranged.

One advantage of this is that the fuel can be removed from the cryogenic pressure vessel essentially completely without (targeted) heating of the cryogenic pressure vessel. A very small amount of fuel can remain at maximum removal in the cryogenic pressure vessel. Since the cryogenic pressure vessel need not be actively heated, the cryogenic pressure vessel has a low temperature when refilling the pressure vessel system with fuel, so that the maximum fuel density or at least a very high fuel density in the cryogenic pressure vessel is achievable. Characterized in that the fuel from the cryogenic pressure vessel via a compressor and the high-pressure gas container (and finally the fuel consumer) can be supplied and thus may have a low pressure, the cryogenic pressure vessel and then taken fuel from the high pressure gas container (and finally the fuel consumer) fed be when the pressure of the fuel in the cryogenic pressure vessel is low or less than the pressure in the high-pressure gas container or less than that of the fuel consumer or a pressure regulator, which is arranged between the high pressure gas container and the fuel consumer, required pressure. As a result, the range of the vehicle in which the pressure vessel system is installed or can be increased. In addition, therefore, the maximum range or at least a very high range of the vehicle is available regardless of the previous use / filling after each complete filling. In addition, the fuel in the high-pressure gas container can be preheated by the environment. The fuel consumer or a pressure regulator, which is arranged between the high-pressure gas container and the fuel consumer, can thus always be supplied with fuel at a sufficiently high pressure and at a sufficiently high temperature. In addition, no tank heat exchanger for heating the cryogenic pressure vessel or the fuel is required in the cryogenic pressure vessel, whereby the manufacturing cost and complexity of the pressure vessel system are reduced.

The cryogenic pressure vessel may e.g. Fuel at a max. Operating pressure / maximum operating pressure / MOP of 300 barü and a temperature of 40 K store. The high pressure gas container may e.g. Fuel at a max. Operating pressure / maximum operating pressure / MOP of 700 barü and a temperature of 300 K store.

In particular, the object is also achieved by a method for supplying fuel from a pressure vessel system arranged in a vehicle to a fuel consumer, in particular a fuel cell, the pressure vessel system comprising at least one cryogenic pressure vessel for storing fuel, in particular hydrogen, and at least one high-pressure gas vessel for storing fuel, in particular hydrogen, the method comprising the steps of: when a density of the fuel in the high-pressure gas container is lower than a limit density value and a pressure of the fuel in the high-pressure gas container is lower than a limit pressure value; compressing the fuel from the cryogenic pressure vessel by means of a compressor and flowing the compressed fuel into the high-pressure gas vessel; when a density of the fuel in the high pressure gas container is lower than a limit density value and a pressure of the fuel in the high pressure gas container is equal to or higher than a threshold pressure value: flowing fuel from the cryogenic pressure container into the high pressure gas container without condensing the fuel; and - supplying fuel from the cryogenic pressure vessel and / or from the high-pressure gas vessel to the fuel consumer.

An advantage of this method is that the fuel to the cryogenic pressure vessel is substantially completely removed without heating the cryogenic pressure vessel. A very small amount of fuel can remain at maximum removal in the cryogenic pressure vessel. Since the cryogenic pressure vessel is not actively heated in the process, the cryogenic pressure vessel has a low temperature when refilling the pressure vessel system with fuel, so that the maximum fuel density or at least a very high fuel density is achieved in the cryogenic pressure vessel. Characterized in that the fuel is removed in the cryogenic pressure vessel via a compressor and thus may have a low pressure, the fuel from the cryogenic pressure vessel can also be removed and the high pressure gas container (and finally the fuel consumer) supplied when the pressure of the fuel in the cryogenic pressure vessel is low or less than the pressure in the high-pressure gas container or less than that of the fuel consumer or a pressure regulator which is between the High pressure gas container and the fuel consumer is arranged, required pressure. This increases the range of the vehicle. In addition, therefore, the maximum range or at least a very high range of the vehicle is ready after each complete filling. The fuel consumer or a pressure regulator, which is arranged between the second high-pressure gas container and the fuel consumer, can thus always be supplied with fuel at a sufficiently high pressure and at a sufficiently high temperature. In addition, no tank heat exchanger for heating the cryogenic pressure vessel or the fuel in the cryogenic pressure vessel is required for the method, whereby a pressure vessel system can be used with low production costs and low complexity. It is particularly possible that the flow of fuel from the cryogenic pressure vessel into the high-pressure gas container without compressing the fuel, only upon satisfaction of the additional condition that the pressure of the fuel in the cryogenic pressure vessel is higher than the pressure of the fuel in the high-pressure gas container is, is being executed.

Also, it is possible that in addition to the condition "when a density of the fuel in the high pressure gas container is lower than a limit density value and a pressure of the fuel in the high pressure gas container is equal to or higher than a threshold pressure value, one or more other conditions must be satisfied the fuel from the cryogenic pressure vessel is allowed to flow into the high pressure gas container without condensing the fuel. Another condition may be e.g. be that the pressure and / or the density of the fuel in the cryogenic pressure vessel drops below a minimum value. Likewise, it is possible that in addition to the condition "when a density of the fuel in the high-pressure gas container is lower than a limit density value and a pressure of the fuel in the high-pressure gas container is lower than a threshold pressure value," one more condition must be satisfied for the fuel to be satisfied is compressed from the cryogenic pressure vessel and the compressed fuel is allowed to flow into the high-pressure gas container. Another condition may be e.g. be that the pressure and / or the density of the fuel in the cryogenic pressure vessel drops below a minimum value. In addition, it is possible that fuel from the cryogenic pressure vessel (without being compressed by the compressor or compressed by the compressor) will flow into the high pressure gas vessel even if the density of the fuel in the high pressure gas vessel is above the limit density value (but eg the pressure of the fuel in the high pressure gas container is below the threshold pressure value). Even if the condition "when a density of the fuel in the high-pressure gas container is lower than a limit density value and a pressure of the fuel in the high-pressure gas container is lower than a threshold pressure value" is met, fuel may be flowed out of the cryogenic pressure container into the high-pressure gas container when e.g. the pressure of the fuel in the cryogenic pressure vessel is greater than the pressure of the fuel in the high pressure gas vessel.

According to one embodiment, the pressure vessel system further comprises a second closable connection line between the outlet of the cryogenic pressure vessel and the inlet of the high-pressure gas container, wherein no compressor is arranged in the second closable connection line. An advantage of this is that fuel from the cryogenic pressure vessel can flow into the high pressure gas container when the pressure of the fuel in the cryogenic pressure vessel is higher than in the high pressure gas vessel without being compressed. Thus, energy can be saved because the compressor does not have to be constantly operated. The fuel may be preconditioned or heated before the fuel is supplied from the cryogenic pressure vessel to the high pressure gas vessel.

According to one embodiment, the pressure vessel system further comprises a lockable third connection line, wherein the third connection line branches off from the second connection line and the second connection line fluidly bypasses the high pressure gas container with the fuel consumer. An advantage of this is that the fuel from the cryogenic pressure vessel is the fuel consumers fed directly. Consequently, fuel can be supplied to the high-pressure gas container and / or heated in the high-pressure gas container by the environment, while at the same time fuel from the cryogenic pressure vessel is supplied to the fuel consumer. The fuel may be preconditioned or heated prior to supplying the fuel to the fuel consumer.

According to one embodiment, the pressure vessel system further comprises a heat exchanger for heating the fuel, wherein the heat exchanger between the cryogenic pressure vessel and the compressor is arranged. One advantage of this is that the compressor can be technically simple and inexpensive since the fuel is heated from the cryogenic pressure vessel before the fuel enters the compressor. This thus reduces the manufacturing costs and complexity of the pressure vessel system.

According to one embodiment, the heat exchanger is arranged such that the fuel from the cryogenic pressure vessel has to flow through the heat exchanger before the fuel can get into the second connection line. The advantage of this is that the second connecting line does not have to be designed for cryogenic fuel or the corresponding temperatures. This reduces the manufacturing cost and complexity of the pressure vessel system. It's also that way ensures that only through the heat exchanger heated fuel (and not heated by the heat exchanger fuel) via the second connecting line from the cryogenic pressure vessel into the high-pressure gas container passes.

According to one embodiment, the pressure vessel system further comprises a fourth closable connection line, wherein the fourth connection line fluidly connects the outlet of the cryogenic pressure container with the inlet of the high-pressure gas container, bypassing the heat exchanger, in particular bypassing the heat exchanger and bypassing the compressor. Hereby, when filling the pressure vessel system with fuel, the fuel for cooling the cryogenic pressure vessel may be used (by flowing the fuel through the cryogenic pressure vessel) and stored at a low temperature after flowing through the cryogenic pressure vessel in the high pressure gas vessel. The advantage of this is that the maximum storage density of fuel in the cryogenic pressure vessel is increased (since the cryogenic pressure vessel is cooled by the fuel flowing through). In addition, more fuel can be stored in the high-pressure gas container.

According to one embodiment, the heat exchanger is arranged such that the fuel from the cryogenic pressure vessel does not have to flow through the heat exchanger before the fuel can flow from the cryogenic pressure vessel into the second connection line. Advantageously, a connection line (e.g., the fourth connection line) which fluidly connects the cryogenic pressure container to the high-pressure gas container may be omitted. When filling the pressure vessel system, the high-pressure gas container with cold fuel, which was led to cool the cryogenic pressure vessel through the cryogenic pressure vessel, are filled through the second connecting line. Thus, the number of connecting lines decreases. This lowers the manufacturing cost of the pressure vessel system.

According to one embodiment of the method, the fuel from the cryogenic pressure vessel is heated prior to supplying the fuel to the compressor by means of a heat exchanger. An advantage of this is that the method can also be carried out with a technically simple pressure tank system. The compressor need not be designed to compress cryogenic fuel, but it is sufficient if the compressor is designed to compress non-cryogenic fuel. Consequently, a low-cost and technically simple pressure vessel system can be used.

According to one embodiment of the method, the fuel from the cryogenic pressure vessel is flowed through a second and / or fourth connection line, bypassing the heat exchanger into the high-pressure gas container. The advantage of this is that fuel from the cryogenic pressure vessel, without actively warming it, can flow into the high-pressure gas container. Thus, cold fuel can be supplied to the high-pressure gas container. Moreover, when filling the pressure vessel system with fuel, the fuel may be used to cool the cryogenic pressure vessel and stored after passing through the cryogenic pressure vessel in the high pressure gas vessel at a low temperature. Thus, the maximum storage density of fuel in the cryogenic pressure vessel is increased. In addition, more fuel can be stored in the high-pressure gas container. Moreover, since the density of the cryogenic fuel mass flow is higher than the mass flow rate of a pre-cooled fuel only at a "warm", i.e., high pressure, gas cylinder, the high pressure gas can be refueled particularly quickly. non-cryogenic, filling or refueling of the high pressure gas container.

The technology disclosed herein relates to a compressed hydrogen storage (CHS) system for storing gaseous fuel under ambient conditions. Such a pressure vessel is in particular a pressure vessel which is installed or can be installed in a motor vehicle. The pressure vessel can be used in a motor vehicle, which is operated for example with compressed ("compressed natural gas" = CNG) or liquefied (LNG) natural gas or with hydrogen. Such a pressure vessel may be, for example, a cryogenic pressure vessel (= CcH2 system) or a high-pressure gas vessel (= CGH2 system).

High-pressure gas container systems (= CGH2 systems) or high-pressure gas containers are formed, substantially at ambient temperatures, fuel (for example hydrogen) permanently at a max. Operating pressure (also called maximum operating pressure or MOP) of about 350 barü (= overpressure relative to the atmospheric pressure), further preferably of about 500 barü and more preferably of about 700 barü store.

The pressure vessel system comprises a cryogenic pressure vessel (= CcH2 pressure vessel). The cryogenic pressure vessel may store fuel in the liquid or supercritical state. A supercritical state of aggregation is a thermodynamic state of a substance which has a higher temperature and a higher pressure than the critical point. Of the critical point denotes the thermodynamic state in which the densities of gas and liquid of the substance coincide, that is, it is single-phase. While one end of the vapor pressure curve in a pT diagram is marked by the triple point, the critical point represents the other end. For hydrogen, the critical point is 33.18 K and 13.0 bar. A cryogenic pressure vessel is particularly suitable for storing the fuel at temperatures significantly below the operating temperature (meaning the temperature range of the vehicle environment in which the vehicle is to be operated) of the motor vehicle, for example at least 50 Kelvin, preferably at least 100 Kelvin or At least 150 Kelvin below the operating temperature of the motor vehicle (usually about - 40 ° C to about + 85 ° C). The fuel may be, for example, hydrogen, which is stored at temperatures of about 34 K to 360 K in the cryogenic pressure vessel. The cryogenic pressure vessel may in particular comprise an inner container which is designed for max. Operating pressures (also called maximum operating pressure or MOP) to about 350 barü (= overpressure relative to the atmospheric pressure), preferably up to about 500 barü, and particularly preferably up to about 700 barü. The fuel is stored in the inner container. The outer container preferably closes off the pressure vessel to the outside. Preferably, the cryogenic pressure vessel comprises a vacuum with an absolute pressure in the range of 10 ^-9 mbar to 10 ^-1 mbar, further preferably from 10 ^-7 mbar to 10 ^-3 mbar and particularly preferably from about 10 ^-5 mbar that at least partially between the inner container and the outer container in an evacuated (intermediate) space or vacuum V is arranged. Storage at temperatures (just) above the critical point has the advantage over storage at temperatures below the critical point that the storage medium is present in a single phase. For example, there is no interface between liquid and gaseous.

In particular, the fuel may be a fuel which is gaseous under normal conditions (pressure of 1.01325 bar and temperature of 0 ° C).

The limit pressure value may be a predetermined pressure value, below which a direct supply of fuel from the high-pressure gas container to the pressure regulator or fuel consumer is no longer possible or is possible only with a very low efficiency or power reduction. The limit pressure value may e.g. 50 barü, further preferably 20 barü and particularly preferably 5 barü amount. The threshold pressure value may be the minimum operating pressure of a pressure regulator disposed between the second high-pressure gas container and the fuel consumer.

The limit density value may be a minimum density value of the fuel in the cryogenic pressure vessel and / or in the high-pressure gas container, which must not be undercut (to prevent safety-critical situations). The limit density value may e.g. 4 g / l, further preferably 1.5 g / l and particularly preferably 0.8 g / l amount.

The high-pressure gas container may in particular be a pressure vessel, which is designed to store non-cryogenic fuel or gaseous fuel. The cryogenic pressure vessel may be designed in particular for storing cryogenic and / or gaseous fuel. In particular, the high-pressure gas container may differ from the cryogenic pressure container in that the cryogenic pressure container is highly thermally insulated in order to cryogenically store the cryogenic fuel in the cryogenic pressure container at low temperatures (compared to the operating temperature of the vehicle). In particular, the high-pressure gas container may have no or only little heat insulation, so that the fuel in the high-pressure gas container is heated by the surroundings or the vehicle or the waste heat of the vehicle. For this purpose, a heat exchanger can be used.

The high-pressure gas container may be a type III pressure vessel. Type III pressure vessels may consist of two components: an inner liner of metal (e.g., steel or aluminum) and a carbon fiber composite material surrounding the inner liner and primarily providing compressive strength.

• 1 eine schematische Ansicht einer ersten Ausführungsform des erfindungsgemäßen Druckbehältersystems;
• 2 eine schematische Ansicht einer zweiten Ausführungsform des erfindungsgemäßen Druckbehältersystems; und
• 3 eine schematische Ansicht einer dritten Ausführungsform des erfindungsgemäßen Druckbehältersystems.

The technology disclosed herein will now be explained with reference to figures. Show it:

• 1 a schematic view of a first embodiment of the pressure vessel system according to the invention;
• 2 a schematic view of a second embodiment of the pressure vessel system according to the invention; and
• 3 a schematic view of a third embodiment of the pressure vessel system according to the invention.

1 shows a schematic view of a first embodiment of the pressure vessel system according to the invention 10 , The pressure vessel system 10 includes two pressure vessels: a cryogenic pressure vessel 20 , a high pressure gas container 60 , The high-pressure gas container 60 may in particular be a non-cryogenic pressure vessel. The cryogenic pressure vessels 20 and the high pressure gas container 60 are each designed to store fuel, in particular hydrogen.

The pressure vessel system 10 can be next to the cryogenic pressure vessel 20 and the high-pressure gas container 60 even more pressure vessels 20 have, for example, one or more cryogenic pressure vessel 20 and one or more high pressure gas containers 60 ,

The cryogenic pressure vessel 20 or an inlet of the cryogenic pressure vessel 20 is via a connection line 17 with a filling opening / tank coupling 15 connected. The filling opening / tank coupling 15 can be connected to a filling source, eg a fuel station. The fuel passes through the filling opening / tank coupling 15 in the cryogenic pressure vessel 20 and is stored in it. An inlet valve 22 or shut-off valve (eg a check valve) is in the connecting line 17 between the cryogenic pressure vessel 20 and the filling opening / tank coupling 15 arranged.

The outlet of the cryogenic pressure vessel 20 is with a first three-way valve 23 fluidly connected. Between the outlet of the cryogenic pressure vessel 20 and the first three-way valve 23 is a first pressure relief valve 26 arranged. The first pressure relief valve 26 releases fuel to the environment and / or to a blow-off management system when the pressure of the fuel in the cryogenic pressure vessel 20 rises above the maximum value.

The first three-way valve 23 is with the outlet of the cryogenic pressure vessel 20 , a heat exchanger 70 for heating the fuel and a fourth connection line 36 fluidly connected. The first three-way valve 23 can get fuel from the cryogenic pressure vessel 20 the heat exchanger 70 and / or the fourth connection line 36 respectively. Also, the first three-way valve 23 designed to block one or both flow paths.

The heat exchanger 70 serves to heat the fuel by means of a heat medium (so-called preconditioning). The fourth connection line 36 fluid connects the outlet of the cryogenic pressure vessel 20 with an inlet of the high pressure gas container 60 , Thus, bypassing the heat exchanger 70 and the compressor 90 Fuel from the cryogenic pressure vessel 20 in the high-pressure gas container 60 , eg during the filling of the pressure vessel system 10 , stream.

Fluidically from the first three-way valve 23 seen from behind the heat exchanger 70 is a second three-way valve 24 arranged. The second three-way valve 24 is with the heat exchanger 70 , a first connection line 32 and a second connection line 34 fluidly connected. The second three-way valve 24 can remove the fuel from the heat exchanger 70 in the first connection line 32 and / or in the second connection line 34 let it flow. Also, the second three-way valve 24 designed to block one or both flow paths.

The heat exchanger 70 may include or be an air heat exchanger, a liquid heat exchanger and / or a capacitor.

The first connection line 32 fluid connects the heat exchanger 70 over the second three-way valve 24 with the inlet of the high pressure gas container 60 , The second connection line 34 Fluid also connects the heat exchanger 70 over the second three-way valve 24 with the inlet of the high pressure gas container 60 , In the first connection line 32 is a compressor 90 for compressing the fuel (from the cryogenic pressure vessel 20 ) arranged. In the second connection line 34 is not a compressor 90 arranged.

In the first connection line 32 is a first check valve 50 arranged, which is a backflow of fuel from the high pressure gas container 60 (or from the second connection line 34 and / or the fourth connection line 36 ) to the compressor 90 prevented. In the second connection line 34 is a second check valve 51 arranged, which is a backflow of fuel from the high pressure gas container 60 (or from the first connection line 32 and / or the fourth connection line 36 ) to the heat exchanger 70 prevented.

The compressor 90 compresses or compresses the fuel from the cryogenic pressure vessel 20 over the first three-way valve 23 , the heat exchanger 70 and the second three-way valve 24 the compressor 90 is supplied. In this way, the fuel can then also from the cryogenic pressure vessel 20 in the high-pressure gas container 60 flow when the pressure of the fuel in the cryogenic pressure vessel 20 below the pressure of the fuel in the high pressure gas container 60 and / or below a threshold pressure value.

A second pressure relief valve 28 is arranged in a connecting line which forms a section between the heat exchangers 70 and the second three-way valve 24 and a portion of the second connection line 34 between the second three-way valve 24 and the second check valve 51 fluidly. If the pressure difference of the fuel at the point after the heat exchanger 70 relative to the pressure of the fuel in the high pressure gas container 60 exceeds a pressure differential value (eg, more than about 300 bar) opens the second pressure relief valve 28 and fuel from the section between the heat exchanger 70 and the second three-way valve 24 flows into the section of the second connecting line 34 between the second three-way valve 24 and the second check valve 51 and from here into the high pressure gas tank 60 and / or via the third connection line 35 directly to the fuel consumer 80 ,

In this way, even with a parked vehicle or engine off (ie, even without availability of an electrical or electronic system) and closed the second three-way valve 24 , Fuel from the cryogenic pressure vessel 20 in the high-pressure gas container 60 stream. In vehicle operation or engine operation, the second three-way valve 24 be controlled and the open second three-way valve 24 Fuel in the second connection line 34 stream. An overflow of the fuel is then also at a small pressure difference between the fuel in the cryogenic pressure vessel 20 and the fuel in the high pressure gas container 60 possible. The pressure difference to overflow of fuel from the cryogenic pressure vessel 20 in the high-pressure gas container 60 is adjustable. The fuel can simultaneously from the cryogenic pressure vessel 20 the high-pressure gas container 60 over the second three-way valve 24 and the second connection line 34 be supplied and the high-pressure gas tank 60 taken and over the connecting line 65 the fuel consumer 80 be supplied.

A third connection line 35 fluid connects a portion of the second connection line 34 (The fluidically after the line from the third pressure relief valve 29 in the second connection line 34 is arranged) between the second three-way valve 24 and the second check valve 51 and a third three-way valve 25 that is between the outlet of the high pressure gas container 60 and the fuel consumer 80 is arranged. The third three-way valve 25 is fluidly connected to the outlet of the high-pressure gas container 60 , the fuel consumer 80 and the third connection line 35 , The third three-way valve 25 can remove the fuel from the high-pressure gas tank 60 and / or from the third connection line 35 to the fuel consumer 80 let it flow. Also is the third three-way valve 25 designed to block one or both flow paths.

Downstream of the first connection line 32 or the second connection line 34 or the fourth connection line 36 and in front of the inlet of the high-pressure gas container 60 is a third pressure relief valve 29 arranged. The third pressure relief valve 29 allows fuel to flow into the environment and / or to a blow-off management system when the pressure of the fuel at that location is too high.

When filling the pressure vessel system 10 with cryogenic fuel, the fuel flows through the cryogenic pressure vessel 20 , whereby this is cooled, and is through the fourth connecting line 36 in the high-pressure gas container 60 let it flow. The flow path through the heat exchanger 70 is closed. During filling, the density of the fuel (f (T, p)) in the high-pressure gas tank 60 supervised. Is the maximum allowable density of fuel in the high pressure gas container 60 achieved, becomes the first three-way valve 23 closed, leaving no fuel through the fourth connection line 36 , the second connection line 34 or the first connection line 32 in the high-pressure gas container 60 flows, ie the first three-way valve 23 closes the outlet of the cryogenic pressure vessel 20 Completely. Now the cryogenic pressure vessel 20 filled with fuel. If both in the pressure vessel 20 as well as in the high-pressure vessel 60 the maximum density or if the maximum allowable pressure or maximum pressure in the cryogenic pressure vessel 20 is reached, the filling is completed (eg by the gas station or filling source, by communication between the vehicle and Befüllquelle or by closing a filling valve) and / or by closing the inlet valve 22 of the cryogenic pressure vessel 20 ,

The fuel flows at appropriately opened three-way valve 25 from the high-pressure gas container 60 through the connection line 65 to the fuel consumer 80 ,

Between the second three-way valve 24 and the compressor 90 is a fourth pressure relief valve in the first embodiment 30 arranged. The fourth pressure relief valve 30 allows fuel to flow into the environment and / or to a blow-off management system when the pressure of the fuel at the location between the fourth pressure relief valve 24 and the compressor 90 is too big.

2 a schematic view of a second embodiment of the pressure vessel system according to the invention 10 , The second embodiment differs from the first embodiment in that no fourth connection line 36 is present, and in that the heat exchanger 70 only after the second three-way valve 24 or after the branch of the second connection line 34 is arranged. That is, the heat exchanger 70 is between the second three-way valve 24 and the compressor 90 arranged.

1. 1. über das erste Dreiwegeventil 23, durch den Wärmetauscher 70, durch das zweite Dreiwegeventil 24 in die zweite Verbindungsleitung 34 und durch den Hochdruckgasbehälter 60 (wobei der Brennstoff hier zwischengespeichert werden kann).
2. 2. über das erste Dreiwegeventil 23, durch den Wärmetauscher 70, durch die erste Verbindungsleitung 32, durch den Verdichter 90 und durch den Hochdruckgasbehälter 60 (wobei der Brennstoff hier zwischengespeichert werden kann).
3. 3. über das erste Dreiwegeventil 23, durch den Wärmetauscher 70, durch das zweite Dreiwegeventil 24 in die zweite Verbindungsleitung 34, in die dritte Verbindungsleitung 35, durch das dritte Dreiwegeventil 25 und somit unter Umgehung des Hochdruckgasbehälters 60 zu dem Brennstoffverbraucher 80.
4. 4. über das erste Dreiwegeventil 23, durch den Wärmetauscher 70, durch das zweite Druckentlastungsventil 28, in die zweite Verbindungsleitung 34 durch den Hochdruckgasbehälter 60 (wobei der Brennstoff hier zwischengespeichert werden kann).

The fuel may come from the cryogenic pressure vessel 20 in the following ways or ways to the fuel consumer 80 reach:

1. 1. over the first three-way valve 23 , through the heat exchanger 70 , through the second three-way valve 24 in the second connection line 34 and through the high-pressure gas container 60 (where the fuel can be cached here).
2. 2. via the first three-way valve 23 , through the heat exchanger 70 , through the first connection line 32 , through the compressor 90 and through the high-pressure gas container 60 (where the fuel can be cached here).
3. 3. via the first three-way valve 23 , through the heat exchanger 70 , through the second three-way valve 24 in the second connection line 34 , in the third connection line 35 , through the third three-way valve 25 and thus bypassing the high-pressure gas tank 60 to the fuel consumer 80 ,
4. 4. via the first three-way valve 23 , through the heat exchanger 70 , through the second pressure relief valve 28 , in the second connection line 34 through the high pressure gas container 60 (where the fuel can be cached here).

If by removing fuel from the high pressure gas container 60 a limit differential pressure between the pressure of the fuel in the cryogenic pressure vessel 20 and the pressure of the fuel in the high pressure gas container 60 is reached, (cryogenic) fuel flows out of the cryogenic pressure vessel 20 via the second pressure relief valve 28 in the high-pressure gas container 60 , The limit differential pressure may be, for example, 0 bar, preferably 100 bar, particularly preferably 300 bar. This function can be purely mechanical and therefore also works when the vehicle is parked or parked. For this purpose, in particular the first three-way valve 23 be formed such that this in the de-energized state, the connection to the heat exchanger 70 releases or switches to "open". Thus, the capacity or the volume of the high pressure gas container 60 used to blow-off the fuel from the cryogenic pressure vessel 20 take.

When the density of the fuel in the high pressure gas container 60 falls below a limit density value (for example, when the high-pressure gas tank 60 is empty or nearly empty) and the pressure of the fuel in the high-pressure gas tank is equal to or higher than a threshold pressure value, fuel becomes through the second connection line 34 allowed to flow (the second three-way valve 24 opens the second connection line 34 and closes the first connection line 32 ). For overflow, the fuel in the cryogenic pressure vessel 20 a higher pressure than the pressure of the fuel in the high pressure gas container 60 , The fuel can through the third connecting line 35 directly to the fuel consumer 80 be supplied or the high pressure gas container 60 be supplied. The fuel can be preconditioned or heated.

When the density of the fuel in the high pressure gas container 60 falls below a limit density value (for example, when the high-pressure gas tank 60 empty or nearly empty) and the pressure of the fuel in the high-pressure gas container 60 falls below a limit pressure value for the (efficient) operation of the fuel consumer 80 necessary, either fuel from the cryogenic pressure vessel 20 uncompressed in the high-pressure gas tank 60 be allowed to flow (provided that the pressure of the fuel in the cryogenic pressure vessel 20 higher than the pressure of the fuel in the high-pressure gas container 60 is) or it may be the second three-way valve 24 be switched such that the second connection line 34 closed and the first connection line 32 is opened. In the latter case, the fuel from the cryogenic pressure vessel 20 through the compressor 90 in the first connection line 32 compressed (ie, the pressure of the fuel is increased) before the fuel to the high-pressure gas tank 60 is supplied. Thus, if in the cryogenic pressure vessel 20 sufficient fuel is present, the high-pressure gas tank 60 or by the high pressure gas container 60 the fuel consumption 80 Fuel with a sufficient pressure (in particular above the limit pressure value) are supplied. Also can in this way fuel from the cryogenic pressure vessel 20 in the high-pressure gas container 60 flow when the pressure of the fuel in the cryogenic pressure vessel 20 is lower than the pressure of the fuel in the high-pressure gas container 60 , Heating the fuel in the cryogenic pressure vessel 20 is not necessary for this.

Alternative to the second connection line 34 There may be a pressure regulator path. The pressure regulator path includes a pressure regulator, via which the pressure of the fuel in the high-pressure gas container 60 mechanically, ie without the need for E / E control, via the cryogenic pressure vessel 20 is set. That is, there is a continuous overflow of fuel from the cryogenic pressure vessel 20 in the high-pressure gas container 60 as soon as the pressure of the fuel in the high pressure gas container 60 falls below a limit pressure value. In this way, the final pressure stroke resulting from overflow of fuel via the second pressure relief valve 28 adjusts, or the Pressure difference between the fuel in the cryogenic pressure vessel 20 and the high-pressure gas container 60 fall below and continue to fuel from the cryogenic pressure vessel 20 be removed. Only when the pressure regulator is completely open and the pressure of the fuel in the high-pressure gas container 60 further decreases by the removal of fuel, the limit density value in the high pressure gas container 60 fell below and the fuel through the compressor 90 in the first connection line 32 guided.

If no removal from the cryogenic pressure vessel takes place over a longer period of time 20 (eg, by prolonged parking of the vehicle), the pressure of the fuel in the cryogenic pressure vessel increases 20 by heat input from the environment. Will the limiting differential pressure between the cryogenic pressure vessel 20 and the high-pressure gas container 60 reaches, kryogener fuel flows through the second pressure relief valve 28 from the cryogenic pressure vessel 20 in the high-pressure gas container 60 , The mass flow of the fuel can be adjusted by a shutter. The cryogenic fuel is due to the heat capacity of the heat exchanger 70 heating the connection line and other components (ie for the second pressure relief valve 28 preconditioned). Alternatively, an additional (air) heat exchanger 70 may be used or the second pressure relief valve 28 is or is designed for cryogenic operation. Consists in the high pressure gas container 60 no more capacity or is a limit pressure value of the fuel (eg 340 bar) in the cryogenic pressure vessel 20 exceeded, the fuel is discharged via a safety valve (eg via a blow-off management system, BMS) into the environment.

The heat exchanger 70 can also be omitted, leaving the compressor 90 cryogenic fuel is supplied. The compressor 90 may in this case be a cryogenic compressor.

Between the heat exchanger 70 and the compressor 90 is a fourth pressure relief valve in the second embodiment 30 arranged. The fourth pressure relief valve 30 allows fuel to flow into the environment and / or to a blow-off management system when the pressure of the fuel at the location between the heat exchanger 70 and the compressor 90 is too big.

3 shows a schematic view of a third embodiment of the pressure vessel system according to the invention. In the 3 The third embodiment shown differs from that in FIG 2 shown second embodiment in that the first pressure relief valve 26 and the second pressure relief valve 28 are absent and instead a 3/2-way valve 39 is arranged in a connecting line, bypassing the second three-way valve 24 the outlet of the cryogenic pressure vessel 20 with the second connection line 34 combines. An outlet of the 3/2-way valve 39 is connected to the second connection line 34 connected and an outlet of the 3/2-way valve is connected to the environment. When a differential pressure between the pressure of the fuel in the cryogenic pressure vessel 20 and the environment exceeds a predetermined limit or maximum, fuel flows through the 3/2-way valve from the cryogenic pressure vessel 20 in the high-pressure gas container 60 , A first limit, where the flow path to the high-pressure gas container 60 is opened, is lower than a second limit, in which the flow path is released into the environment. That is, before the blow-off from the cryogenic pressure vessel 20 is blown into the environment, the Überströmpfad or flow path into the high pressure gas container 60 open.

The pressure of the fuel in the cryogenic pressure vessel increases 20 on and over the second threshold because in the high pressure gas tank 60 already the same pressure as in the cryogenic pressure vessel 20 prevails, the 3/2-way valve opens to the environment and blows fuel from the cryogenic 20 in the environment. Instead of a 3/2-way valve, a valve with an E / E function is also possible. With the E / E function, the differential pressure can be set variably and according to the situation.

In particular, it is advantageous if the fuel in the cryogenic pressure vessel 20 as long as possible has a high density. As a result, the heat capacity in the cryogenic pressure vessel 20 high and the temperature rise is minimized by a constant insulation heat flux.

The 3 / 2-way valve is in particular designed such that it in the de-energized state fuel from the cryogenic pressure vessel 20 in the high-pressure gas container 60 can flow when the first limit is exceeded.

The first limit, when it exceeds fuel from the cryogenic pressure vessel 20 through the 3/2-way valve in the high-pressure gas tank 60 can be flowed, for example, 320 bar. The second limit, when it exceeds fuel from the cryogenic pressure vessel 20 can be discharged or blown into the environment, for example, 350 bar.

For the sake of legibility, the term "at least one" has been omitted for simplicity. If a feature of the technology disclosed herein is described in singular form (eg, the / a cryogenic pressure vessel, the / a high pressure gas vessel, the / Compressor, etc.) should be at the same time also their plurality disclosed (eg, the at least one cryogenic pressure vessel, the at least one high-pressure gas tank, the at least one compressor, etc.).

The foregoing 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 NUMBERS

10

Pressure vessel system

15

Filling / tanker coupling

17

Connecting line from the tank coupling to the cryogenic pressure vessel

20

cryogenic pressure vessel

22

Inlet valve of the cryogenic pressure vessel

23

first three-way valve

24

second three-way valve

25

third three-way valve

26

first pressure relief valve

28

second pressure relief valve

29

third pressure relief valve

30

fourth pressure relief valve

32

first connection line

34

second connection line

35

third connection line

36

fourth connection line

39

3/2-way valve

50

first check valve

51

second check valve

60

High-pressure gas tank

65

Connecting line from the high pressure gas container to the fuel consumer

70

heat exchangers

80

fuel consumers

90

compressor

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been 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.

Cited patent literature

• EP 1546601 B1 [0008]

Claims (10)

A pressure vessel system (10) for a vehicle, wherein the pressure vessel system (10) - at least one cryogenic pressure vessel for storing fuel, in particular hydrogen, and - at least one high pressure gas container (60) for storing fuel, in particular hydrogen, wherein an inlet of the cryogenic Pressure vessel (20) via a connecting line (17) with a filling opening (15) for filling the cryogenic pressure vessel (20) is fluidly connected, wherein an outlet of the high-pressure gas container (60) via a connecting line (65) with a fuel consumer (80), in particular one Fuel cell, fluid-connected, characterized in that in a first lockable connection line (32) between the outlet of the cryogenic pressure vessel (20) and an inlet of the high pressure gas container (60), a compressor (90) for compressing the fuel from the cryogenic pressure vessel (20) is arranged. Pressure vessel system (10) after Claim 1 , further comprising a second closable connection line (34) between the outlet of the cryogenic pressure vessel (20) and the inlet of the high pressure gas container (60), wherein in the second lockable connection line (34) no compressor (90) is arranged. Pressure vessel system (10) after Claim 1 or 2 , further comprising a closable third connecting line (35), wherein the third connecting line (35) branches off from the second connecting line (34) and the second connecting line (34) fluidly bypasses the high pressure gas container (60) with the fuel consumer (80). The pressure vessel system (10) of any preceding claim, further comprising a heat exchanger for heating the fuel, wherein the heat exchanger is disposed between the cryogenic pressure vessel (20) and the compressor (90). Pressure vessel system (10) after Claim 4 wherein the heat exchanger is arranged such that the fuel from the cryogenic pressure vessel (20) must flow through the heat exchanger before the fuel can enter the second connection line (34). Pressure vessel system (10) after Claim 4 or 5 further comprising a fourth closable connecting line (36), wherein the fourth connecting line (36) the outlet of the cryogenic pressure vessel (20) with the inlet of the high pressure gas container (60) bypassing the heat exchanger, in particular bypassing the heat exchanger and bypassing the compressor ( 90), fluidly connected. Pressure vessel system (10) after Claim 4 wherein the heat exchanger is arranged such that the fuel from the cryogenic pressure vessel (20) does not have to flow through the heat exchanger before the fuel can flow from the cryogenic pressure vessel (20) into the second connection line (34). Method for supplying fuel from a pressure vessel system (10) arranged in a vehicle to a fuel consumer (80), in particular a fuel cell, wherein the pressure vessel system (10) - At least one cryogenic pressure vessel (20) for storing fuel, in particular hydrogen, and at least one high-pressure gas container (60) for storing fuel, in particular hydrogen, comprises the method comprising the steps of: when a density of the fuel in the high-pressure gas container (60) is lower than a limit density value and a pressure of the fuel in the high-pressure gas container (60) is lower than a threshold pressure value: compressing the fuel from the cryogenic pressure container (20) by means of a compressor (90) and flowing the compressed fuel into the high pressure gas container (60); when a density of the fuel in the high pressure gas container (60) is lower than a limit density value and a pressure of the fuel in the high pressure gas container (60) is equal to or higher than a threshold pressure value: flowing fuel from the cryogenic pressure container (20) into the high pressure gas container (60) without condensing the fuel by means of the compressor (90); and - Supplying fuel from the cryogenic pressure vessel (20) and / or from the high pressure gas container (60) to the fuel consumer (80). Method according to Claim 8 wherein the fuel from the cryogenic pressure vessel (20) is heated prior to supplying the fuel to the compressor (90) by means of a heat exchanger. Method according to Claim 8 or 9 wherein the fuel from the cryogenic pressure vessel (20) through a second and / or fourth connecting line (36), bypassing the heat exchanger in the high pressure gas container (60) is allowed to flow.

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