METHOD AND DEVICE FOR FILLING A LIQUID GAS CONTAINER

Description

[0001] The invention relates to a method and a device for filling a liquefied gas storage facility.

[0002] The invention relates more particularly to a method for filling a liquefied gas storage facility by means of a liquefied gas tank, the method comprising a step of transferring liquefied gas from the tank to the storage facility by pressure differential, in which the storage facility has, prior to the transfer step, an internal pressure greater than the internal pressure of the tank, the method comprising, prior to the transfer step, a step of establishing fluidic connection by pressure balancing of the tank (10) and the storage facility (2) to ensure a reduction in the pressure in the storage facility (2) for the benefit of the tank (10) and a step of increasing the pressure in the tank (10) via a pressurizing device (3, 6).

[0003] US 2018 / 202609 A discloses such a method.

[0004] Typically, liquid hydrogen is delivered to a facility by pressure differential. Typically, the storage to be filled is at a pressure between 3 and 13 bara and the liquid contained in the delivery tank is at a pressure between 0.3 barg and 13 barg.

[0005] To achieve this transfer by pressure differential (without a pump), in most cases, it is first necessary to pressurize the tank of the delivery semi-trailer to a pressure typically 1 barg higher than the pressure of the fixed storage to be filled.

[0006] This pressurization is typically achieved by a device called a pressurization heater. Cold liquid is drawn from the tank by gravity and vaporized in a typically atmospheric heat exchanger located at a low point in the tank. The device therefore includes a hot point at the bottom. A thermosiphon flow is formed and the hot gas created is then naturally returned to the tank. This causes pressurization of the tank. The pressurization rate typically depends on the size of the heating exchanger and the diameter of the pipes.

[0007] This device does, however, have drawbacks. For example, the time required for pressurization can be relatively long. Furthermore, since the driving force of the thermosiphon flow depends on the liquid head and the density difference between the liquid and the gas, this device works less well when the tank is empty or almost empty. Pressurization takes even longer to achieve. Furthermore, this pressurization introduces heat into the system. This results in the liquid hydrogen heating, which ultimately increases the amount of gas lost through evaporation in logistics.

[0008] An aim of the present invention is to overcome all or part of the drawbacks of the prior art noted above.

[0009] To this end, the method according to the invention, which is also in accordance with the generic definition given in the preamble above, is essentially characterized in that the step of increasing the pressure in the reservoir (10) via the pressurization device (3, 6) is carried out at the same time as the step of fluidically connecting the reservoir (10) and the storage (2).

[0010] Furthermore, embodiments of the invention may include one or more of the following features: the step of fluidly connecting the reservoir and the storage lowers the pressure in the storage for the benefit of the reservoir to a determined level in which the pressure in the storage is equal to the pressure in the reservoir or exceeds the pressure in the reservoir by a determined limited value of between 0.5 and 5 bar and in particular between 0.5 and 1 bar, the step of increasing the pressure in the reservoir increases the pressure in the reservoir to a determined level in which the pressure in the reservoir exceeds the pressure in the storage by a determined value of between 0.5 and 5 bar and in particular between 1 and 2 bar, the step of fluidly connecting the reservoir and the storage is carried out via at least one transfer pipe having one end connected to the lower part and / or to the upper part of the reservoir and another end connected to the lower part and / or to the upper part of the storage,the step of fluidly connecting the reservoir and the storage is carried out via at least one transfer pipe having one end connected to the upper part of the reservoir and one end connected to the upper part of the storage, the device for pressurizing the reservoir comprises a circuit for pressurizing the reservoir comprising, between a first fluid suction end connected to the reservoir and a second fluid return end connected to the reservoir, a fluid heating member and a set of heating valve(s) for controlling the circulation of the fluid in said pressurizing circuit.

[0011] The invention also relates to a device for filling a liquefied gas storage tank comprising a liquefied gas tank intended to transfer liquefied gas into the storage tank by pressure differential, the device comprising a circuit for pressurizing the tank comprising, between a first fluid suction end connected to the tank and a second fluid return end connected to the tank, a fluid heating member and a set of heating valve(s) for controlling the circulation of the fluid in said pressurizing circuit, the device further comprising at least one fluid transfer pipe comprising a first end connected to the tank and a second end intended to be connected to the storage tank and comprising a set of transfer valve(s) for controlling the circulation of the fluid in said transfer pipe,the device comprising a set of sensor(s) for measuring the pressure in the tank and / or in the storage, the device further comprising a fluid transfer pipe having a first end connected to the upper end of the tank and another end intended to be connected to the upper end of the storage.,

[0012] According to other possible features, the device comprises an electronic data storage and processing control member configured to control at least part of the set of valves, the control member being configured to ensure, prior to a transfer of fluid from the tank to the storage when the pressure in the storage is higher than the pressure in the tank: an opening of the set of transfer valve(s) to ensure a pressure transfer between the storage and the tank, and, after or during pressure transfer between the storage and the tank, an opening of the set of reheating valve(s) to increase the pressure within the tank, then a closing of the set of reheating valve(s) and an opening of the set of transfer valve(s) to ensure a transfer of liquefied gas from the tank to the storage by pressure differential.

[0013] The invention may also relate to any alternative device or method comprising any combination of the above or below features within the scope of the claims.

[0014] Other features and advantages will become apparent upon reading the following description, made with reference to the [ Fig. 1 ] which represents a schematic and partial view illustrating an example of structure and operation of a device according to the invention.

[0015] Installation 1 shown in [ Fig. 1 ] comprises a device for filling a storage 2 of liquefied gas. The storage 2 is for example a fixed double-jacketed storage insulated under vacuum and containing liquefied hydrogen.

[0016] The installation 1 comprises a tank 10 of liquefied gas (liquefied hydrogen for example), for example carried by a semi-trailer and intended to transfer liquefied gas into the storage 2 by pressure differential.

[0017] The tank 10 comprises a pressurization heater, i.e. a circuit 3 for pressurizing the tank 10 as mentioned above. This pressurization circuit 3 comprises, between a first fluid suction end 4 connected to the tank 10 (lower part in particular) and a second fluid return end 5 connected to the tank 10 (in the upper part in particular), a fluid heating member 6 (atmospheric heat exchanger or other arranged in the lower part) and a set of heating valve(s) 7-19. For example, the pressurization circuit 3 comprises a heating valve 7, preferably controlled and automatic, for controlling the circulation of the fluid in said pressurization circuit 3 (by thermosiphon) and a shut-off valve 19 (preferably manually controlled).

[0018] The device 1 further comprises at least one fluid transfer pipe (and in this example two pipes 8, 9) each comprising a first end connected to the reservoir 10 and at least one second end intended to be connected to the storage 2. The transfer pipe(s) 8, 9 may be connected in parallel to the lower end and / or to the upper end of the storage 2 via appropriate circuitry.

[0019] The installation and in particular each transfer pipe 8, 9 comprises a set of transfer valves 11, 12, 13, 14, 15 for controlling the circulation of the fluid in the transfer pipe(s) 8, 9. For example, a first transfer pipe 8 connected to the lower end of the tank 10 comprises two valves 11 in series which may consist respectively of an automatic safety shut-off valve and a manually controlled shut-off valve.

[0020] In the same way, the second transfer pipe 9 (connected to the upper part of the tank 10) can comprise two valves 15 in series which can be constituted for example respectively by an automatic safety shut-off valve and a manually controlled shut-off valve.

[0021] Each transfer pipe 8, 9 may have a flexible end which is connected to the circuitry of the storage 2 allowing communication with the upper end and / or with the lower end of the storage. The storage circuitry advantageously comprises a set of valves 12, 13, 14 which may be piloted or manual valves. The tank 10 and the storage 2 may comprise conventional venting / protection valve devices.

[0022] Thus, a delivery operator can connect the transfer pipe(s) 8, 9 from the mobile tank 10 to the circuitry of the storage 2. If the pressure in the storage 2 is higher than the pressure in the tank 10 preventing a transfer by pressure difference, the operator can open the valves 14 and 15 (connecting the upper parts of the tank 10 and the storage 2) and / or the valves 13 and 11 (connecting the lower parts of the tank 10 and the storage 2) to balance the pressures within the tank 10 and the storage 2.According to another non-imitative possibility, the operator can open the valve 14 (connecting the upper part of the storage 2) and use the line 9 connected to the upper part of the tank (by opening the valve 15) and / or the line 8 connected to the lower part of the tank 10 (by opening the valves 11 and 13) When the pressure within the tank 10 reaches or approaches sufficiently the storage pressure (for example pressure difference of 5 bar or less (and in particular difference between 0.5 and 1 bar for example). The transfer valves 11, 15 can be closed.

[0023] The operator can then open the heating valves 7, 19 to increase the pressure in the tank 10 by activating the heating loop.

[0024] When the pressure in the tank 10 sufficiently exceeds the pressure in the storage 2 (for example from 0.5 to 5 bar, in particular one to two bar), the heating valves 7, 19 can be closed. All or part of the transfer valves 11, 15, 12, 13, 14 can then be opened to ensure filling of the storage by pressure differential. This filling can consist of supplying the storage 2 from below (corresponding valve 13 open) to increase the pressure in the storage and / or from above (corresponding valve 14 open) to reduce the pressure in the storage 2.

[0025] It should be noted that, advantageously, the increase in pressure in the tank 10 (activating the heating loop) can be started even during the pressure balancing operation within the tank 10 and the storage 2 (valves 11, 15 and 14 and / or 13 open). This makes it possible to further accelerate the pressurization of the tank 10.

[0026] The tank 10 and / or the storage 2 may comprise a set of pressure measuring sensors 16, 17.

[0027] The installation (for example the mobile tank 10 or an external control unit) may comprise an electronic control member 18 for storing and processing data configured to control all or part of the valves. This electronic control member 18 may comprise a microprocessor, a computer or any other suitable device.

[0028] This control member 18 can control all or part of the valves or other components of the device and can receive in particular the aforementioned pressure measurements as well as filling or stopping instructions.

[0029] This control member 18 can automate or control all or part of the manual operations described above.

[0030] Thus, when a filling tank 10 is connected to a storage 2 for the purpose of filling it and the pressure in the storage 2 is greater than the pressure in the tank 10, the control member 18 can be configured to ensure, prior to a transfer of fluid from the tank 10 to the storage 2, an opening of the set of transfer valve(s) 11, 15 and 14 to ensure a pressure transfer between the storage 2 and the tank 10.

[0031] As before, this is intended to lower the storage pressure in favor of tank 10.

[0032] When a determined pressure balance is reached, these valves are closed to isolate the storage 2 and the tank 10. In this configuration (or even before the end of this pressure transfer), the pressurization of the tank 10 can be activated (opening of the set of heating valves 7, 19 to increase the pressure within the tank 10 as described above).

[0033] When the pressure in the tank 10 reaches a sufficient value above the pressure in the storage 2, the pressurization can be interrupted and a transfer of liquid from the tank to the storage by pressure differential can be carried out.

[0034] The method and device thus makes it possible to use the pressure of storage 2 to pressurize the delivery tank 10 more quickly. The estimated time saving can reach in certain cases 30 minutes to 2 hours per delivery, particularly in the case of several successive deliveries.

[0035] The tank 10 is thus pressurized by relatively cold gas. The energy inputs into the tank 10 are therefore limited.

Claims

1. Method for filling a storage vessel (2) with liquefied gas by means of a tank (10) of liquefied gas, the method comprising a step of transferring liquefied gas from the tank (10) into the storage vessel (2) by means of a pressure differential, wherein the storage vessel (2) prior to the transfer step has an internal pressure higher than the internal pressure of the tank (10), the method comprising, prior to the transfer step, a step of placing the tank (10) and the storage vessel (2) in fluidic communication by equalizing of pressure between the tank and the storage vessel in order to ensure a drop in the pressure in the storage vessel (2) to the benefit of the tank (10), and a step of increasing the pressure in the tank (10) using a pressurizing device (3, 6), characterized in that the step of increasing the pressure in the tank (10) via the pressurizing device (3, 6) is performed at the same time as the step of placing the tank (10) and the storage vessel (2) in fluidic communication.

2. Method according to Claim 1, characterized in that the step of placing the tank (10) and the storage vessel (2) in fluidic communication lowers the pressure in the storage vessel (2) to the benefit of the tank (10) down to a determined level in which the pressure in the storage vessel (2) is equal to the pressure in the tank (10) or exceeds the pressure in the tank (10) by a determined limited value of between 0.5 and 5 bar, and notably of between 0.5 and 1 bar.

3. Method according to either one of Claims 1 and 2, characterized in that the step of increasing the pressure in the tank (10) increases the pressure in the tank (10) up to a determined level in which the pressure in the tank (10) exceeds the pressure in the storage vessel (2) by a determined value of between 0.5 and 5 bar, and notably of between 1 and 2 bar.

4. Method according to any one of Claims 1 to 3, characterized in that the step of placing the tank (10) and the storage vessel (2) in fluidic communication is performed via at least one transfer pipe (8, 9) having one end connected to the lower part and / or to the upper part of the tank (10) and another end connected to the lower part and / or to the upper part of the storage vessel (2) .

5. Method according to Claim 3, characterized in that the step of placing the tank (10) and the storage vessel (2) in fluidic communication is performed via at least one transfer pipe (9) having one end connected to the upper part of the tank (10) and one end connected to the upper part of the storage vessel (2).

6. Method according to any one of Claims 1 to 5, characterized in that the device (3, 6) for pressurizing the tank (10) comprises a pressurizing circuit (3) for pressurizing the tank (10) comprising, between a fluid-aspiration first end (4) connected to the tank (10) and a fluid-return second end (5) connected to the tank (10), a fluid heating member (6) and a set of one or more heating valves (7, 19) for controlling the circulation of the fluid in said pressurizing circuit (3).

7. Device for filling a liquefied-gas storage vessel (2) comprising a tank (10) of liquefied gas intended to transfer liquefied gas into the storage vessel (2) by means of a pressure differential, the device comprising a pressurizing circuit (3) for pressurizing the tank (10), comprising, between a fluid-aspiration first end (4) connected to the tank (10) and a fluid-return second end (5) connected to the tank (10), a fluid heating member (6) and a set of one or more heating valves (7, 19) for controlling the circulation of the fluid in said pressurizing circuit (3), the device further comprising at least one fluid transfer pipe (8, 9) comprising a first end connected to the tank (10) and a second end intended to be connected to the storage vessel (2) and comprising a set of one or more transfer valves (11, 12, 13, 14, 15) for controlling the circulation of the fluid in said transfer pipe (8, 9), the device comprising a set of one or more sensors (16, 17) for measuring the pressure in the tank (10) and / or in the storage vessel (2), characterized in that the device comprises a fluid transfer pipe (9) having a first end connected to the upper end of the tank and another end intended to be connected to the upper end of the storage vessel (2), and in that it comprises an electronic control and data processing and storage member (18) configured to control at least part of the set of one or more valves, the control member (18) being configured to perform, prior to a transfer of fluid from the tank (10) to the storage vessel (2) when the pressure in the storage vessel (2) is higher than the pressure in the tank (10): an opening of the set of one or more transfer valves in order to ensure a transfer of pressure by equalizing of pressure between the storage vessel (2) and the tank (10), and, during the transfer of pressure between the storage vessel (2) and the tank (10), an opening of the set of one or more heating valves in order to increase the pressure in the tank (10), then a closing of the set of one or more heating valves and an opening of the set of one or more transfer valves in order to ensure a transfer of liquefied gas from the tank (10) to the storage vessel (2) using a pressure differential.