Distribution station and method for transferring a fluid via such a station

Abstract

The invention relates to a station (100) for distributing a pressurised fluid such as hydrogen, comprising a transfer line (TL) connecting in this order a source (10) of a cryogenic fluid, a system (20) for compressing the cryogenic fluid, and a distributor (30) configured to distribute the cryogenic fluid to a tank (8) to be filled, the transfer line (TL) comprising a first circuit (L1) configured to ensure a flow of a gaseous stream of the cryogenic fluid from a first area of the source (10) to a first region of the compression system (20), and vice versa; a second circuit (L2) configured to ensure a flow of a liquid stream of the cryogenic fluid from a second area of the source (10) to a second region of the compression system (20), and vice versa; and a third circuit (L3), referred to as main circuit, configured to ensure a flow of a stream of the cryogenic fluid from an outlet of the compression system (20) to the distributor (30). According to the invention, the distribution station (100) comprises a bypass line (L4) allowing the transfer line (TL) to bypass the compression system (20), the bypass line (L4) comprising a first end connected to the first circuit (L1) at a first junction point JP1 located upstream of the compression system (20), and a second end connected to the main circuit (L3) at a second junction point JP2 located downstream of the compression system (20).

Description

Distribution station and method for transferring a fluid via such a station

[0001] The invention relates to a pressurized cryogenic fluid distribution station. Specifically, it is a liquid-to-liquid station configured to store a cryogenic fluid, particularly in a liquid state, and deliver this fluid in a pressurized liquid state. This type of pressurized liquid state is called a subcooled liquid. The fluid in question may be hydrogen.

[0002] The invention also relates to a method for transferring a cryogenic fluid via such a station. The method is specifically designed to recover an undistributed mass of fluid. This could be residual mass after a vehicle tank filling operation or mass used for thermalizing a transfer line.

[0003] Hydrogen is one of the energy carriers used to decarbonize the transport sector, particularly heavy vehicle transport. To maximize the range of these vehicles on long journeys, the use of subcooled liquid hydrogen (16 bar and 25K) is one of the solutions being deployed. Liquid hydrogen has a higher density than gaseous hydrogen, allowing for the storage of a greater amount of energy in a given tank volume.

[0004] To inject subcooled liquid hydrogen into a vehicle tank, liquid-to-liquid dispensing stations are used. These stations comprise a transfer line connecting a source containing a cryogenic fluid, typically in liquid form, a cryogenic fluid compression system, and a dispenser configured to deliver the liquid cryogenic fluid to a tank for refueling. Specifically, the compression system and the dispenser are connected by the main circuitry of the transfer line.

[0005] The main circuitry is vacuum-insulated to maintain the cryogenic fluid at the dispenser outlet at a set temperature, known as the filling temperature. Furthermore, depending on the floor equipment layout, the main circuitry has a length that can vary from 20 meters to 80 meters, and an internal diameter ranging from 3 / 4" (26.7 mm) to 2" (60.3 mm), more precisely 1" (33.4 mm).

[0006] During the commissioning of a liquid-to-liquid distribution station, or after maintenance, a cooling step (commonly called thermalization) may be necessary on the transfer line, and in particular on the main circuitry. This cooling involves lowering the temperature of the components (e.g., the flow meter) and elements (e.g., the filter(s) and valve(s)) in the main circuitry to temperatures close to the filling temperature.

[0007] For this cooling process, a flow of cryogenic hydrogen from the source can be used. This flow can be transferred to the distributor via the compression system, or it can be transferred directly to the distributor, bypassing the compression system. In all cases, the cryogenic fluid used for thermalizing the secondary circuitry heats up and vaporizes. The mass of vapor generated is generally vented to the atmosphere using a purge line connected to a vent. Such venting therefore constitutes a loss of material.

[0008] Furthermore, at the end of a vehicle tank filling operation, the hydrogen present in the main circuitry is generally at a pressure of 16 bara and a maximum temperature of 25.5 K. Thermal inputs in the transfer line, and in particular in the main circuitry, have the effect of increasing the fluid pressure, with the risk of exceeding the maximum pressure that the transfer line can withstand, or the maximum setting pressure of the safety valves.

[0009] To ensure the safety of the dispensing station between successive refills, it may be necessary to reduce the hydrogen pressure in the main circuitry (generally to a pressure between 2 and 5 bar). To achieve this, the hydrogen in the main circuitry may be vented to the atmosphere. Such venting also represents a loss.

[0010] In both cases mentioned above, the amount of fluid vented can be more or less significant depending on the length of the main circuitry.

[0011] For example, in a main circuit approximately 50 meters long and 1 inch (33.4 mm) in diameter, where the liquid hydrogen used for cooling is at 25 K and a pressure of 16 bar (corresponding to a density of 67.3 kg / m³), the total mass of hydrogen is approximately 2.5 kg. Almost all of this will be released into the atmosphere between successive refilling operations.

[0012] For a total mass of approximately 60 kg of hydrogen actually supplied to a tank during refueling, venting 2.5 kg of residual hydrogen in the main circuitry represents a loss of approximately 4% of the total mass supplied to the tank. This percentage of mass loss is incompatible with the objectives of reducing costs and limiting the environmental impact of hydrogen technologies.

[0013] One aim of the invention is to overcome, at least in part, the disadvantages listed above.

[0014] Accordingly, in a first aspect, the invention relates to a distribution station for a pressurized fluid such as hydrogen. The station comprises a transfer line connecting, in this order, a source of cryogenic fluid, a cryogenic fluid compression system, and a distributor configured to distribute the cryogenic fluid to a tank to be filled.

[0015] Specifically, the transfer line includes a first circuit configured to ensure the flow of a gaseous stream of the cryogenic fluid from a first area of ​​the source to a first region of the compression system, and vice versa. Furthermore, the transfer line includes a second circuit configured to ensure the flow of a liquid stream of the cryogenic fluid from a second area of ​​the source to a second region of the compression system, and vice versa. Finally, the transfer line includes a third circuit configured to ensure the flow of a stream of the cryogenic fluid from an outlet of the compression system to the distributor. This main circuit is referred to as the primary circuit.

[0016] According to this first aspect of the invention, the station includes a branch line from the transfer line at the compression system. This branch line has a first end connected to the first circuitry at a first junction point located upstream of the compression system. Furthermore, this branch line has a second end connected to the main circuitry at a second junction point located downstream of the compression system. The branch line is also called the return circuitry or fourth circuitry.

[0017] Thanks to the return circuitry, the mass of fluid present in the main circuitry after a filling operation or after a cooling operation of the main circuitry can be returned either to the source or to the compression system for reuse.

[0018] Furthermore, embodiments of the invention according to this first aspect may include one or more of the following features: the compression system comprises a container defining a volume configured to store a reserve of cryogenic fluid, and at least one compression element configured to be supplied with cryogenic fluid contained in the reserve; the container of the compression system is double-walled, defining a thermally insulated, sealed space, for example, under vacuum; the compression element comprises at least one pump housed within the container, for example, immersed at least partially in the reserve, and at least one actuator for actuating the pump(s); the actuator(s) are located outside the container; the compression element comprises two pumps configured to be actuated asynchronously with respect to each other to deliver a continuous flow of cryogenic fluid pumped into the main circuitry.The compression system further includes a discharge circuit configured to transfer the cryogenic fluid pumped by the compression unit to the main circuit. At least a portion of the circuit includes a set of valve(s) to control the flow of the cryogenic fluid in said portion. The set of valve(s) includes a first valve on the first circuit, located upstream of the first junction point. The set of valve(s) includes a third valve on the main circuit, located downstream of the second junction point. The set of valve(s) includes a fourth valve on the bypass circuit. The station includes a controller configured to control the opening and / or closing of all or part of the set of valve(s). The main circuit includes a flow meter. The main circuit includes a filter.The main circuitry includes a relief valve configured to vent overpressure; the main circuitry includes a temperature sensor; the main circuitry includes a pressure sensor; the main circuitry is equipped with a mechanical coupling device between the station and the tank to be filled; the main circuitry is equipped with an anti-pull-out system; the flow meter, filter, valve, pressure sensor, temperature sensor, coupling device, and anti-pull-out system are part of a physical unit consisting of the distributor; the flow meter, filter, and valve are located upstream of the third valve; the pressure sensor, temperature sensor, coupling device, and anti-pull-out system are located downstream of the third valve; the station includes a vent line connected to the main circuitry at a third junction point.The vent line is equipped with a fifth valve.

[0019] According to a second aspect, the invention relates to a method for transferring a cryogenic fluid using a distribution station according to any one of the embodiments described above.

[0020] The process includes the following steps: a step of regulating a liquid mass level and gaseous mass level of the cryogenic fluid in the compression system, a step of transferring a flow of the cryogenic fluid from the compression system to the distributor via the main circuitry of the transfer line, and a step of returning a flow of the vaporized cryogenic fluid to the source and / or to the compression system, via the bypass circuitry of the compression system.

[0021] Advantageously, the step of regulating the level of the liquid mass and the gaseous mass of the cryogenic fluid in the compression system includes a first operation of transferring a gaseous flow from the first zone of the source to the first region of the compression system, and a second operation of transferring a liquid flow from the second zone of the source to the second region of the compression system.

[0022] Other features and advantages will become apparent upon reading the description below, which refers to the following figures in which:

[0023] is a schematic representation of an example of a distribution station according to the invention, the station comprising a transfer line connecting a source, a compression system and a distributor, and a branch line of the transfer line at the compression system.

[0024] illustrates steps in a transfer process using the distribution station shown in the figure.

[0025] With reference to the aforementioned, the invention relates to a dispensing station 100 for a pressurized fluid such as hydrogen. It is, in particular, a liquid-liquid type station, that is to say, a station configured to store a cryogenic fluid, notably in a liquid state, and to deliver this fluid in a liquid state.

[0026] The distribution station 100 includes a transfer line TL which connects in this order the following elements: a source 10 intended to contain a cryogenic fluid, especially in liquid form, a compression system 20 to compress the cryogenic fluid, and a distributor 30 to distribute the cryogenic fluid, especially in liquid or subcooled form, to a tank 8 to be filled.

[0027] The above order defines the direction of fluid flow during a tank filling operation 8.

[0028] In particular, the cryogenic fluid source 10 is a container which delimits a first volume in which we can distinguish a first zone intended to store a mass of the cryogenic fluid in the gaseous state and a second zone intended to store a mass of the cryogenic fluid in the liquid state.

[0029] The first zone of spring 10 represents a portion of spring 10 relatively far from the ground. This is the upper part of spring 10. The second zone represents a portion of the spring relatively close to the ground. This is the lower part of spring 10.

[0030] The gaseous mass of the cryogenic fluid has a relatively low density. It occupies the first zone of source 10, that is, the upper part of source 10. The liquid mass of the cryogenic fluid has a relatively high density. It occupies the second zone of source 10, that is, the lower part of source 10.

[0031] The compression system 20 may be that described in document FR3148279, the contents of which are incorporated into this application. The following lines describe certain characteristics of this compression system 20 for a better understanding of the present invention.

[0032] The compression system 20 includes a container 21 configured to receive a flow of cryogenic fluid from the source 10 and temporarily store this flow. The compression system 20 also includes a compression element 22 for pumping the cryogenic fluid stored in the container 21.

[0033] Container 21 extends vertically and defines a second volume, which in turn defines a first region for storing the cryogenic fluid in its gaseous state and a second region for storing the cryogenic fluid in its liquid state. The first and second regions represent the upper and lower parts of container 21, respectively. The upper part is the furthest from the ground, and the lower part is the closest to the ground.

[0034] Furthermore, the container 21 may be double-walled, defining a thermally insulated, airtight space, for example, under vacuum. Specifically, the container 21 may comprise an inner tank for storing the cryogenic fluid and an outer tank arranged around the inner tank, defining the airtight space around it.

[0035] The compression unit 22 includes at least one pump housed within the volume defined by the container 21. This may, in particular, be a piston pump. The compression unit 22 also includes at least one actuator for actuating the pump(s). This is preferably a linear actuator. The actuator(s) are mounted on an upper cover of the container 21.

[0036] In the illustrated example, the compression unit 22 comprises two pumps arranged in parallel with respect to the main circuitry L3. These pumps are configured to be operated asynchronously with respect to each other in order to deliver a continuous flow of cryogenic fluid pumped into the main circuitry L3 of the transfer line TL.

[0037] To receive a fluid flow from the source 10, the compression system 20 may include a supply circuit. This is connected to the first circuit L1 and the second circuit L2 of the transfer line TL. Similarly, to transfer a pumped fluid flow to the main circuit L3, the compression system 20 may include a discharge circuit. The pumps are connected in parallel to the discharge circuit.

[0038] According to the invention, the distribution station 100 includes a branch line L4 from the transfer line TL at the compression system 200. In particular, the branch line L4 includes a first end connected to the first circuitry L1 at a first junction point JP1 located upstream of the compression system 200. The branch line L4 also includes a second end connected to the main circuitry L3 at a second junction point JP2 located downstream of the compression system 200.

[0039] The L4 branch line is also subsequently referred to as the “return circuit” or “fourth circuit”.

[0040] Thanks to the return circuitry, the mass of fluid present in the main circuitry L3 after a filling operation or after a cooling operation of the main circuitry L3 can be returned to the source 10 and / or to the compression system 20 for reuse.

[0041] Advantageously, at least a portion of the circuitry L1, L2, L3, L4 may include a set of valve(s) V1, V2, V3, V4 configured to control the flow of the cryogenic fluid in said portion of the circuitry. In the illustrated example, each of the circuitry 1, 2, 3, 4 is provided with a valve, respectively: first valve V1, second valve V2, third valve V3, fourth valve V4.

[0042] In particular, the first valve V1 is located upstream of the first junction point JP1. The third valve V3 is located downstream of the second junction point JP2. The third valve V3 is called the main valve.

[0043] Advantageously, the main circuit L3 can include the following elements in this order: a flow meter 3, a filter 4, and a valve 5. This order defines the direction of fluid flow during tank 8 filling. The flow meter 3, the filter 4, and the valve 5 are all located upstream of the main valve V3. In particular, the flow meter 3 and the filter 4 are located upstream of the second junction point JP2.

[0044] In the illustrated example, valve 5 is located downstream of the second junction point JP2. In an alternative configuration not shown, valve 5 can be located upstream of the second junction point JP2.

[0045] In addition, the main circuit L3 can also include a TT temperature sensor and a PT pressure sensor. In the illustrated example, these TT and PT sensors are located downstream of the main valve V3 and as close as possible to the distributor 30. In an alternative configuration not shown, the TT and PT sensors can be located upstream of the main valve V3.

[0046] Finally, the main circuit L3 can be equipped at its end with a coupling device 7 configured to ensure a smooth connection between the distribution station 100 and the tank 8 to be filled. This coupling device 7 can take the form of a nozzle equipped with a set of safety devices such as a shut-off valve, a check valve, etc.

[0047] Upstream of the coupling device 7, the main circuitry L3 may include an anti-pull-out system 6 configured to disconnect the coupling device 7 from the rest of the main circuitry L3 in the event of excessive pull-out force exerted on the coupling device 7.

[0048] It should be noted that the flow meter 3, the filter 4, the valve, the temperature TT sensor, the pressure PT sensor, the coupling device 7 and the anti-pull-out system 6 can be arranged within the same physical entity constituted by the distributor 30.

[0049] To ensure the safety of the distribution station 100 in the event of overpressure in the main circuitry L3, particularly between two refuelings; or when a return of the cryogenic fluid to the source 10 or to the compression system 20 is not possible, the distribution station 100 advantageously includes at least a fifth circuitry L5. This is a purge line directed to a vent.

[0050] This L5 purge line also allows for the reduction of pressure in tank 8 when it arrives overfilled at the start of refueling (pressure exceeding 10 bar). This L5 purge line also allows for the evacuation of hydrogen gas during the initial commissioning of the dispensing station 100 or after maintenance during the cooling-down phases.

[0051] The L5 purge line is connected to the main circuit L3 at a third junction point JP3, which is located upstream of the anti-pull-out system 6. The L5 purge line includes a fifth valve. Advantageously, the L5 purge line communicates with valve 5.

[0052] To control the opening and / or closing of all or part of the valve assembly (V1, V2, V3, V4, V5), the distribution station 100 advantageously includes a controller. This can be an electronic system that communicates with the tank 8 to be filled.

[0053] According to a second aspect, the invention relates to a transfer method 200 using the distribution station 100 described above.

[0054] The process 200 includes the following steps: a step S1 of regulating a level of liquid mass and gaseous mass of the cryogenic fluid in the compression system 20, a step S2 of transferring a flow of the cryogenic fluid from the compression system 20 to the distributor 30, via the main circuitry L3 of the transfer line TL, and a step S3 of returning a flow of the vaporized cryogenic fluid to the source 10 and / or to the compression system 200.

[0055] The vaporized cryogenic fluid originates from the main circuitry L3. It is returned to the compression system 20 via the L4 bypass circuitry of the compression system 20. To achieve this, the third valve V3 and the fourth valve V4 are held in the open position, while the fifth valve V5 (where a purge line L5 is provided) is held in the closed position.

[0056] Step S1, which regulates the levels of the liquid and gaseous mass of the cryogenic fluid in the compression system 20, comprises a first operation transferring a gaseous mass flow from the first zone of the source 10 to the first region of the compression system, and a second operation transferring a liquid mass flow from the second zone of the source 10 to the second region of the compression system 200. To accomplish this, the first valve V1 of the first circuit L1 and the second valve V2 of the second circuit L2 are held in the open position.

[0057] It should be noted that steps S1 to S3 can be performed as part of a cooling (thermalization) of the main circuit L3. This thermalization can apply to the entire length of the main circuit L3 or only to a portion of it, including the flow meter 3. In the first case, the main valve V3 of the main circuit L3 is held in the open position to allow the cryogenic fluid to flow to the coupling device 7. In the second case, the main valve V3 is held in the closed position to limit the thermalization to only those elements of the main circuit L3 located upstream of the third valve V3.

[0058] Step S3 alone (without steps S1 and S2) can be executed as part of a source conditioning process 10. Step S3 then allows a return of a mass of liquid fluid from the second region of the compression system 20 to the second zone of the source 10. To do this, the first valve V1 and the fifth valve V5 (when a purge line L5 is provided) are held in the closed position; while the second valve V2, the third valve V3 and the fourth valve V4 are held in the open position.

[0059] Process 200 may also include a tank filling step 8. This filling step replaces step S3, which redirects a flow of vaporized cryogenic fluid to the source 10 and / or to the compression system 200. Therefore, for this filling step, the fourth valve V4 must be closed. Similarly, the fifth valve V5 (when a purge line L5 is provided) must also be kept closed.

Claims

Station (100) for distributing a pressurized fluid such as hydrogen, comprising a transfer line (TL) connecting in this order a source (10) of a cryogenic fluid, a cryogenic fluid compression system (20), and a distributor (30) configured to distribute the cryogenic fluid to a tank (8) to be filled, the transfer line (TL) comprising a first circuitry (L1) configured to ensure a flow of a gaseous stream of the cryogenic fluid from a first zone of the source (10) to a first region of the compression system (20), and vice versa, a second circuitry (L2) configured to ensure a flow of a liquid stream of the cryogenic fluid from a second zone of the source (10) to a second region of the compression system (20), and vice versa, and a third circuitry (L3), called the main circuitry,configured to ensure the flow of a stream of cryogenic fluid from an outlet of the compression system (20) to the distributor (30), characterized in that it comprises a branch line (L4) of the transfer line (TL) at the compression system (20), the branch line (L4) comprising a first end connected to the first circuitry (L1) at a first junction point (JP1) located upstream of the compression system (20), and a second end connected to the main circuitry (L3) at a second junction point (JP2) located downstream of the compression system (20). Station (100) according to the preceding claim, wherein the compression system (20) comprises a container (21) delimiting a volume configured to store a reserve of cryogenic fluid, and at least one compression member (22) configured to be supplied with cryogenic fluid from the reserve. Station (100) according to any one of the preceding claims, wherein the compression member (22) comprises at least one pump housed in the container (21), for example immersed at least partially in the reservoir, and at least one actuator, preferably linear, for actuating the pump(s), the actuator(s) being disposed outside the container (21). Station (100) according to the preceding claim, wherein the compression member (22) comprises two pumps configured to be actuated asynchronously with respect to each other to deliver a continuous flow of cryogenic fluid pumped into the main circuitry (L3). Station (100) according to the preceding claim, wherein the compression system (20) further comprises a discharge circuit configured to transfer the cryogenic fluid pumped by the compression member (22) to the main circuit (L3). Station (100) according to any one of the preceding claims wherein at least a portion of the circuitry (L1, L2, L3, L4) comprises a set of valve(s) (V1, V2, V3, V4), respectively first valve (V1), second valve (V2), third valve (V3) and fourth valve (V4), for controlling the flow of the cryogenic fluid in said portion. Station (100) according to the preceding claim, comprising a controller configured to control an opening and / or closing of all or part of the set of valve(s) (V1, V2, V3, V4). Station (100) according to any one of the preceding claims, wherein the main circuitry (L3) comprises at least one of the following: a flow meter (3), a filter (4), a relief valve (5) configured to relieve overpressure, a temperature sensor (TT), a pressure sensor (PT), a mechanical coupling device (7) between the station (100) and the tank (8) to be filled, an anti-tear system (6). Station (100) according to the preceding claim taken in its connection with claim 6, wherein the flow meter (3), the filter (4) and the valve (5) are located upstream of the third valve (V3), the pressure sensor (PT), the temperature sensor (TT), the mechanical coupling device (7) and the anti-pull-out system (6) being located downstream of the third valve (V3). Station (100) according to any one of claims 8 or 9, wherein the flow meter (3), the filter (4), the discharge valve (5), the pressure sensor (PT), the temperature sensor (TT), the mechanical coupling device (7), and the anti-pull-out system (6) form part of a physical entity constituted by the distributor (30). Station (100) according to any one of the preceding claims comprising a vent line (L5) connected to the main circuitry (L3) at a third junction point (JP3), the vent line (L5) being equipped with a fifth valve (V5). Method (200) of transferring a cryogenic fluid using a station (100) according to any one of the preceding claims, the method (200) comprising the following steps: a step (S1) of regulating a liquid mass level and a gaseous mass level of the cryogenic fluid in the compression system (20), a step (S2) of transferring a flow of the cryogenic fluid from the compression system (20) to the distributor (30) via the main circuitry (L3) of the transfer line (TL), a step (S3) of returning a flow of the vaporized cryogenic fluid to the source (10) and / or to the compression system (20), via the bypass circuitry (L4) of the compression system (20). Method (200) according to the preceding claim, wherein the step (S1) of regulating a level of liquid mass and gaseous mass of the cryogenic fluid in the compression system (20) comprises a first operation of transferring a gaseous flow from the first zone of the source (10) to the first region of the compression system (20), and a second operation of transferring a liquid flow from the second zone of the source (10) to the second region of the compression system (20).

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