CONNECTION KIT, TANK SYSTEM AND PUMP

Description

[0001] The present invention relates to a connection set for detachably connecting a fuel pump having a return line for cryogenic gas to a tank system with a container for a two-phase mixture of cryogenic gas and cryogenic liquid, which tank system has a degassing line extending from a head region of the container, comprising: a degassing socket connectable to the degassing line and a degassing plug connectable to the return line for detachably connecting to the degassing socket. The invention further relates to a tank system and a fuel pump, each equipped with a part of the connection set.

[0002] A connection fitting of the type mentioned is known, for example, from US 6 196 280 B1.

[0003] To increase the energy content of energy sources that are gaseous under normal conditions, they are either compressed and stored in a pressure vessel for transport and storage purposes, or cooled to a low temperature, liquefied, and stored in a temperature-insulated container. For example, liquefied natural gas (LNG) or liquefied hydrogen are stored as a two-phase mixture with a high energy density to power vehicles, for example, to power internal combustion engines or vehicle fuel cells. Here, too, the container for the two-phase mixture of cryogenic gas and cryogenic liquid is pressurized relative to the ambient air. In the case of LNG, for example, the pressure is between approximately 7-10 bar, at which refueling occurs, and approximately 16 bar, above which a controlled boil-off occurs via safety valves.The internal pressure of the tank must also be monitored during filling (fueling) of the tank. For this purpose, cryogenic gas is extracted from the top of the tank during the cryogenic fluid supply to prevent excessive internal pressure. The tank system's degassing line and the return line of the fuel pump are used for this purpose.

[0004] For safety reasons, the degassing line is equipped with two shut-off elements connected in series. These shut-off elements are usually a manually operated shut-off valve or an electric switching valve, and in series with this, a (second) electric switching valve or a check valve. Manually operated shut-off valves increase the risk of incorrect operation, e.g., leaving the valve open after refueling, and require an accessible control element, which represents an additional thermal bridge. Both manually operated shut-off valves and electric switching valves must be large due to the usually high mass flows to be transmitted and the low temperatures to which they are exposed. An electric switching valve also requires an electrical interface, which represents an additional thermal bridge and source of error.Check valves have the disadvantage that the line they are fitted with can only be operated in one direction, meaning that in the case of a degassing line, no gas can be discharged. On the other hand, check valves are usually smaller than other shut-off devices and seal reliably.

[0005] The present invention aims to create a connection fitting, a tank system and a fuel pump which ensure the required safety during operation and filling and which can be used reliably.

[0006] According to a first aspect of the invention, this object is achieved with a connection fitting of the type mentioned in the introduction, which is characterized in that the degassing socket contains two spring-loaded check valves connected in series with a blocking direction facing away from the container and the degassing plug has a pin by means of which both check valves of the degassing socket are opened against their blocking direction when the degassing plug is connected.

[0007] The degassing socket, with its two series-connected check valves and their locking directions, ensures that no cryogenic gas escapes from the degassing line during tank system operation. The space-saving design of check valves allows their installation within the degassing socket. The pin on the degassing plug opens the two check valves one after the other, even during refueling, ensuring safe connection and disconnection of the degassing plug to the degassing socket and thus to the degassing line. The connection set with the degassing socket enables the degassing line to be operated in both directions; neither an electrical interface nor an operating lever is required.

[0008] In a preferred embodiment, in which the dispenser further comprises a feed line for cryogenic liquid and the tank system further comprises a filling line leading into the container, the connection fitting comprises a filling socket connectable to the filling line and a filling plug connectable to the feed line for detachable connection to the filling socket. The filling socket contains two series-connected, spring-loaded check valves with the blocking direction facing away from the container, and the filling plug has a pin through which both check valves of the filling socket are opened against their blocking direction when the filling plug is connected. Like the degassing socket and the degassing plug, the filling socket and the filling plug meet the high safety requirements both during operation and during refueling.

[0009] For ease of use, it is particularly advantageous if the filling and degassing plugs are anchored to a common fuel nozzle.

[0010] According to a second aspect, the invention provides a tank system comprising a container for holding a two-phase mixture of cryogenic gas and cryogenic liquid, a degassing line extending from a head region of the container, and a degassing socket connected to the degassing line for detachably connecting a degassing plug of the aforementioned type. The degassing socket is characterized in that the degassing socket contains two spring-loaded check valves connected in series with a blocking direction facing away from the container. In a preferred embodiment, the tank system further comprises a filling line opening into the container, a filling socket connected to the filling line for detachably connecting a filling plug of the aforementioned type, the filling socket containing two spring-loaded check valves connected in series with a blocking direction facing away from the container.Regarding the advantages of such a tank system, please refer to the above comments on the connection fitting.

[0011] It is also advantageous if the container, the filling line, and the degassing line are arranged inside a thermally insulating housing, which is penetrated by the filling sleeve and the degassing sleeve. This eliminates the need for further thermal insulation of the container, the filling line, and / or the degassing line.

[0012] It is particularly advantageous if the filling line and the degassing line are free of switching valves. Because the two check valves are connected in series in the filling sleeve and the degassing sleeve, additional switching valves in the filling and degassing lines are not required. This helps save installation space and reduces the tank system's susceptibility to failure.

[0013] According to a third aspect, the invention provides a fuel pump comprising a return line for cryogenic gas and a degassing plug connected to the return line for detachable connection to a degassing socket of the aforementioned type. The degassing plug is characterized in that the degassing plug has a pin through which both check valves of the degassing socket are opened against their blocking direction when the degassing plug is connected. For further embodiments and advantages, reference is made to the above explanations regarding the connection fitting.

[0014] The invention is explained in more detail below using an embodiment shown in the accompanying drawing. In this drawing: Fig. 1 a tank system and a fuel pump with a connection fitting according to the invention in the form of a simplified hydraulic diagram.

[0015] Fig. 1 shows a tank system 1 with a container 2 in which a two-phase mixture 3 of cryogenic gas 4 and cryogenic liquid 5 is accommodated. Furthermore, Fig. 1 a fuel pump 6 and a connection fitting 7 via which the fuel pump 6 can be detachably connected to the tank system 1, as will be explained in more detail below.

[0016] The less dense cryogenic gas 4 is located in a head region 8 of the container 2, whereas the denser cryogenic liquid 5 collects in a bottom region 9 of the container. A degassing line 10 of the tank system 1 extends from the head region 8 of the container 2. The degassing line 10 can be connected (here: connected, ie, connected) to a degassing socket 11 of the connection fitting 7 at its end facing away from the container 2, ie, can be connected or connected in a sealed and non-detachable manner, e.g., welded, glued, or integrally formed.

[0017] The dispenser 6 has a return line 12 for cryogenic gas 4. The return line 12 can be connected to a degassing plug 13 of the connection fitting 7 (here: similarly connected). The degassing plug 13 can be detachably connected to the degassing socket 11, ie, it can be coupled and detached again in a liquid- and gas-tight manner.

[0018] In order to tightly seal the container 2 and the degassing line 10 extending from its head region 8 to the outside during operation of the tank system 1, the degassing bushing 11 contains two spring-loaded check valves 14a, 14b connected in series, each of which has a blocking direction R facing away from the container 2.

[0019] The degassing plug 13 has a pin 15. When the degassing plug 13 is connected to the degassing socket 11 - e.g. for filling (fueling) the container 2 of the tank system 1 - the pin 15 of the degassing plug 13 engages in the degassing socket 11 and opens in sequence first the outer check valve 14a of the degassing socket 11 and subsequently the inner check valve 14b of the degassing socket 11. Both check valves 14a, 14b of the degassing socket 11 are thus opened by its pin 15 against their blocking direction R when the degassing plug 13 is connected. The degassing line 10 can thus be operated in both directions, ie in the blocking direction R and in an opposite flow direction of the check valves 14a, 14b.

[0020] According to the example of the Fig. 1 a feed line 16 for cryogenic liquid 5, from which the tank system 1 is fed when refueling the container 2. Furthermore, for refueling, the tank system 1 has a filling line 17 opening into the container 2. The filling line 17 optionally opens, as is known to the person skilled in the art, into a spray nozzle 18 inside the container 2. A filling socket 19 of the connection fitting 7 can be connected (here: connected) to the filling line 17 of the tank system 1. This filling socket - similar to the degassing socket 11 - contains two series-connected, spring-loaded check valves 20a, 20b, whose blocking directions R also face away from the container 2. A filling plug 21 of the connection fitting 7 can be connected (here again: connected) to the feed line 16 of the fuel pump 6 and can be detachably connected to the filling socket 19.Comparable to the degassing plug 13, the filling plug 21 also has a pin 22 which, when the filling plug 21 is connected to the filling socket 19, first opens the outer check valve 20a of the filling socket 19 and subsequently opens the inner check valve 20b of the filling socket 19, so that both check valves 20a, 20b of the filling socket 19 are open against their respective blocking direction R when the filling plug 21 is connected and consequently the filling line 17 can also be operated in both directions.

[0021] It is understood that when the degassing plug 13 is removed from the degassing socket 11 or when the filling plug 21 is removed from the filling socket 19, the check valves 14a, 14b, 20a, 20b are released and close due to their spring loading. Furthermore, it is understood that the check valves 14a, 14b of the degassing socket 11 and the check valves 20a, 20b of the filling socket 19 are mechanically separated from each other due to their series connection, so that they close independently of each other or are opened by the pins 15, 22.

[0022] In the example of Fig. 1 , the filling plug 21 and the degassing plug 13 are optionally anchored to a common filling nozzle 23 so that they can be handled together.

[0023] In Fig. 1 What is not shown is that the fuel pump 6 is generally connected to a reservoir for a two-phase mixture of cryogenic gas 4 and cryogenic liquid 5, from which the fuel pump 6 withdraws cryogenic liquid 5 in order to feed it into the tank system 1 during refueling using the feed line 16, and into which the fuel pump 6 returns cryogenic gas 4 from the tank system 1 using the return line 12. For this purpose, the fuel pump 6 may further have one or more pumps and / or coolers as required.

[0024] In the illustrated example, the container 2, the filling line 17, and the degassing line 10 are optionally arranged inside a thermally insulating housing 24, which is penetrated by the filling sleeve 19 and the degassing sleeve 11. In the illustrated embodiment, the filling line 17 and the degassing line 10 are free of switching valves.

[0025] For the sake of completeness, further optional components are described below which the tank system 1 in the exemplary embodiment of the Fig. 1 includes, but is not limited to,

[0026] In this embodiment of the tank system 1, for example, a withdrawal line 26 branches off from the degassing line 10 at a branching point 25, via which a consumer M that can be connected to a consumer console 27 can be fed. The extraction line 26 leads through a heat exchanger 29 which is supplied with heat via a heating console 28 and, in this example, has two optional switching valves 30, 31 before it flows into the consumer console 27. The extraction line 26 also has two pressure sensors 32, 33 and a temperature sensor 34 for regulating the extraction of cryogenic gas 4 from the container 2. These sensors 32, 33, 34, together with the switching valves 30, 31, a further temperature sensor 35 arranged in the container 2, a fill level sensor 36 arranged in the container 2 and a further switching valve 37, are wired into a control console 38 where an external control S can be connected. The further switching valve 37 activates or deactivatesIn this example, deactivates a heater 39 arranged inside the container 2 via a heating line 40, which branches off from the extraction line 26 at a branch 41 located downstream of the heat exchanger 29, leads through the heater 39 and opens back into the extraction line 26 at an inlet 42 located downstream of the branch 41; a throttle 43 is arranged in the extraction line 26 between the branch 41 and the inlet 42. In addition to the extraction line 26 and the heating line 40, two overpressure lines 44, 45 pass through the housing 24, which in the example shown originate from the degassing line 10, are each provided with a pressure relief valve 46, 47 and open into an overpressure console 48.

[0027] The invention is not limited to the embodiment shown, but includes all variants, modifications and combinations thereof that fall within the scope of the appended claims.

Claims

1. A connection set for detachably connecting a dispenser (6), which has a return line (12) for cryogenic gas (4), to a tank system (1) with a container (2) for a two-phase mixture (3) of cryogenic gas (4) and cryogenic liquid (5), which tank system (1) has a degassing line (10) extending from a head region (8) of the container (2), comprising: a degassing socket (11), which is connectable to the degassing line (10), and a degassing plug (13) which is connectable to the return line (12), for detachably connecting to the degassing socket (11), characterised in that the degassing socket (11) contains two spring-loaded non-return valves (14a, 14b), which are connected in series and which have a blocking direction (R) facing away from the container (2), and the degassing plug (13) has a pin (15), by means of which both non-return valves (14a, 14b) of the degassing socket (11) are opened against their blocking direction (R) when the degassing plug (13) is connected.

2. The connection set according to claim 1, further comprising a filling socket (19), which is connectable to a filling line (17) of the tank system (1) opening into the container (2), and a filling plug (21), which is connectable to a feed line (16) of the dispenser (6) suitable for cryogenic liquid (5), for detachably connecting to the filling socket (19), wherein the filling socket (19) contains two spring-loaded non-return valves (20a, 20b), which are connected in series and which have a blocking direction (R) facing away from the container (2), and the filling plug (21) has a pin (22), by means of which both non-return valves (20a, 20b) of the filling socket (19) are opened against their blocking direction (R) when the filling plug (21) is connected.

3. The connection set according to claim 2, characterised in that the filling and degassing plugs (21, 13) are anchored to a common nozzle (23).

4. A tank system, comprising a container (2) for receiving a two-phase mixture (3) of cryogenic gas (4) and cryogenic liquid (5), a degassing line (10) extending from a head region (8) of the container (2) and a degassing socket (11) in communication with the degassing line (10) for detachably connecting a degassing plug (13) of the connection set (7) according to any one of claims 1 to 3, characterised in that the degassing socket (11) contains two spring-loaded non-return valves (14a, 14b), which are connected in series and which have a blocking direction (R) facing away from the container (2).

5. The tank system according to claim 4, further comprising a filling line (17) opening into the container (2), a filling socket (19) in communication with the filling line (17) for detachably connecting a filling plug (21) of the connection set (7) according to claim 2 or 3, characterised in that the filling socket (19) contains two spring-loaded non-return valves (20a, 20b), which are connected in series and which have a blocking direction (R) facing away from the container (2).

6. The tank system according to claim 5, characterised in that the container (2), the filling line (17) and the degassing line (10) are arranged in the interior of a thermally insulating housing (24) which is penetrated by the filling socket (19) and by the degassing socket (11).

7. The tank system according to claim 6, characterised in that the filling line (17) and the degassing line (10) are free of switching valves.

8. A dispenser, comprising a return line (12) for cryogenic gas (4) and a degassing plug (13) in communication with a return line (12) for detachably connecting to a degassing socket (11) of the connection set (7) according to any one of claims 1 to 3, characterised in that the degassing plug (13) has a pin (15), by means of which both non-return valves (14a, 14b) of the degassing socket (11) are opened against their blocking direction (R) when the degassing plug (13) is connected.

9. The dispenser according to claim 8, further comprising a feed line (16) for cryogenic liquid (5), a filling plug (21) in communication with a feed line (16) for detachably connecting to a filling socket (19) of the connection set (7) according to claim 2 or 3, characterised in that the filling plug (21) has a pin (22), by means of which both non-return valves (20a, 20b) of the filling socket (19) are opened against their blocking direction (R) when the filling plug (21) is connected.

10. The dispenser according to claim 9, characterised in that the filling and degassing plugs (21, 13) are anchored to a common nozzle (23).