Cryogenic fluid storage and distribution installation.

Abstract

The invention relates to a cryogenic fluid storage and distribution system, for example, for liquid hydrogen, comprising a cryogenic tank (2) equipped with a withdrawal line (3) configured to allow liquid to be withdrawn from the tank (2) and a tank (2) pressurization device comprising an injection line (5) connected to the tank (2) and configured to allow fluid to be injected into the tank (2) to pressurize the tank (2), for example, to maintain the pressure in the tank (2) during liquid withdrawal. The pressurization device comprises an ejector (4) disposed on the injection line (5). The ejector (4) has a first inlet for motive gas connected to a pressurized gas source (6) of the system (1), a second suction inlet connected to another fluid source, preferably liquefied, and the outlet of the ejector (4) is connected to the tank (2). (Short figure: Fig. 1)

Description

Title of the invention: Cryogenic fluid storage and distribution installation.

[0001] The invention relates to a cryogenic fluid storage and distribution installation.

[0002] The installation is advantageously applicable to the storage and distribution of liquid hydrogen.

[0003] The invention relates more particularly to a cryogenic fluid storage and distribution installation, for example liquid hydrogen, comprising a cryogenic tank equipped with a withdrawal line configured to allow liquid to be withdrawn from the tank and a tank pressurization device comprising an injection line connected to the tank and configured to allow fluid to be injected into the tank to pressurize the tank, for example to maintain pressure in the tank during liquid withdrawal.

[0004] The invention relates in particular to the withdrawal of cryogenic liquid (for example, liquid hydrogen) from a cryogenic tank (fixed or mobile). In some applications, the withdrawal rate of liquid is between one and two tonnes per hour (or more may be required).

[0005] Cryogenic liquid storage facilities are generally not equipped with withdrawal pumps but instead use a storage pressurization device (for example an atmospheric exchanger positioned under the tank) allowing self-pressurization.

[0006] This device compensates for the loss of liquid volume in the tank during withdrawal by reinjecting cold hydrogen that has been withdrawn and vaporized. This vaporization gas can be taken from the liquid portion and vaporized before being reinjected into the gaseous phase of the storage tank.

[0007] These pressurization devices, however, have limited vaporization capacities, allowing limited liquid withdrawal rates under nominal conditions.

[0008] One solution would be to use an "external" atmospheric heat exchanger, allowing its size to be adapted to the vaporization requirements to meet the high withdrawal flow rate. This solution, however, faces the challenge of ensuring a very low pressure drop across the entire external circuit, given the size of the exchanger and the need for flexible connection hoses on the return circuit. The resulting pressure drop will undoubtedly be significantly greater than the hydrostatic pressure available in the storage tank as the sole driving force.

[0009] One object of the present invention is to overcome all or part of the disadvantages of the prior art noted above.

[0010] To this end, the installation according to the invention, which also conforms to the generic definition given in the preamble above, is essentially characterized in that the pressurization device comprises an ejector disposed on the injection line, the ejector having a first inlet for motive gas connected to a source of pressurized gas of the installation, a second suction inlet connected to another source of fluid, preferably liquefied, the outlet of the ejector being connected to the tank.

[0011] Furthermore, embodiments of the invention may include one or more of the following features: - the second suction inlet of the ejector is connected to the discharge line (3), - the installation includes a valve, for example an isolation valve and / or a pressure and / or fluid flow control valve for the fluid admitted into the second suction inlet of the ejector, - the pressurized gas source includes at least one pressurized gas storage unit, preferably equipped with a pressure and / or flow regulator, - The installation includes a pressure sensor for the flow at the ejector outlet and / or in the tank, - The pressure regulator is configured to regulate the pressure and / or flow rate of the engine gas based on the pressure sensor measurement. - The installation includes a flow temperature sensor located at the ejector outlet, - the injection line includes a pressure and / or flow control valve arranged in parallel with the ejector, - The valve located in parallel with the ejector is configured to regulate the temperature of the fluid downstream of the ejector based on the temperature sensor measurement. - The pressure and / or fluid flow control valve for the second suction inlet of the ejector is configured to regulate the pressure and / or flow rate according to the temperature sensor measurement, - The installation includes a heat exchanger for reheating the fluid flow admitted to the second suction inlet of the ejector. - the pressurization device further includes an additional tank pressurization element comprising for example an atmospheric exchanger positioned under the tank configured to cooperate, for example simultaneously with the ejector to allow increasing the flow rate of the fluid withdrawn from the tank.

[0012] 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.

[0013] Other features and advantages will become apparent from the following description, given with reference to the figures in which: Brief description of the figures

[0014] The invention will be better understood upon reading the following description, given solely by way of example and made with reference to the accompanying drawings in which:

[0015] [Fig-1] is a schematic and partial vertical cross-sectional view illustrating an example of the structure and operation of an installation according to the invention. Detailed description

[0016] In all figures, the same references refer to the same elements.

[0017] In this detailed description, the following embodiments are examples. Although the description refers to one or more embodiments, this does not mean that the features apply only to a single embodiment. Simple features from different embodiments can also be combined and / or interchanged to provide other embodiments.

[0018] The cryogenic fluid storage and distribution installation 1 shown includes a cryogenic tank 2 (for example, double-jacketed). This tank 2 is equipped with a withdrawal line 3 configured to allow liquid to be withdrawn from the tank 2.

[0019] The withdrawal line 3 is without a pump.

[0020] The installation 1 further includes a device for pressurizing the tank 2 comprising an injection line 5 connected to the tank 2 (preferably opening into the upper part of the tank 2) and configured to allow the injection of fluid into the tank 2 to pressurize the tank 2.

[0021] For example, this injection line 5 makes it possible to maintain a determined pressure in the reservoir 2, in particular when drawing off liquid.

[0022] This pressurization device includes an ejector 4 disposed on the injection line 5 having a first inlet for motive gas connected to a source 6 of pressurized gas from the installation 1, a second suction inlet connected to the withdrawal line 3 while the outlet of the ejector 4 is connected to the tank 2 by the injection line 5.

[0023] The ejector 4 draws liquid from the source reservoir 2 through the withdrawal line 3 using the driving force generated by the pressurized gas flow supplied by the pressurized gas source 6. This produces a cold gas (for example, at a temperature) at the discharge (outlet) of the ejector 4. between the saturation temperature and a warming of OK to 50K above this equilibrium for the case of hydrogen).

[0024] This structure makes it possible to generate in the pressurization line 5 a fluid flow with a controlled flow rate and temperature to ensure the pressurization of the tank 2. This makes it possible, in particular, to maintain the pressure in the tank 2 even for relatively high flow rates (for example, exceeding one ton per hour). This pressurization device makes it possible to provide a flow rate of pressurizing gas fluid far exceeding the capacities of known pressurization systems.

[0025] Furthermore, this pressurization device allows for relatively lower gas (engine gas) consumption compared to simply injecting a flow of (relatively hot) gas into the tank from a gas source. In addition, injecting a relatively cold gas reduces the re-condensation effect in tank 2 and thus better stabilizes the pressure.

[0026] The second inlet of the ejector draws a small fraction of the withdrawn liquid. As illustrated, this can be achieved via a bypass line equipped with a pressure and / or flow control valve 10.

[0027] This liquid is drawn into the ejector 4 by venturi effect with the driving force generated by the flow of driving gas supplied by the source 6. The source 6 comprises for example one or more pressurized gas cylinders preferably equipped with a pressure-reducing device such as a valve 7 configured to ensure a determined flow or pressure.

[0028] The ejector 4 can be sized to obtain at its discharge outlet a mixture of liquid and gas at a determined pressure to compensate for example the pressure losses of the circuit between the ejector outlet 4 and the inlet of the tank 2.

[0029] The flow rate supplied by the ejector 4 into the gaseous volume of the reservoir 2 can be sized to compensate for the loss of the liquid withdrawn at a given withdrawal pressure.

[0030] The mixture of liquid and gas (typically hydrogen) makes it possible to produce a flow sufficient to regulate the pressure in the tank 2 by limiting the quantity of relatively hot gas supplied by the pressurized gas source 6.

[0031] The liquid-gaseous mixture (typically hydrogen) makes it possible to produce a sufficient flow rate to regulate the pressure in the tank 2 by limiting the amount of relatively hot gas supplied by the pressurized gas source 6. Indeed, each molecule used for pressurization and taken from the withdrawal flow 3 can be saved in the hot gas source 6. The pressure available in the hot gas source 6 is often much higher than the pressure required in the tank 2 to limit the transport volume. This excess pressure is then not directly usable in the tank 2, and can even have a negative effect during expansion. Direct injection into tank 2 is possible because hydrogen or helium heats up during expansion through a valve. By injecting a hot gas, the heat exchange between the cold parts of tank 2 and the injected gas leads to densification or even liquefaction of this gas, which partially offsets the pressurization effect. This detrimental compensating effect is more pronounced if the temperature difference is large. For pressure control, it is therefore preferable to inject a pressurization gas that is not excessively overheated against equilibrium. Mixing it with some of the withdrawn liquid thus allows, in addition to saving molecules, thermalization at a temperature level more suitable for pressure regulation.

[0032] The consumption of liquid withdrawn is relatively low compared to the flow rate of liquid withdrawn and transferred to the user (for example, on the order of a few percent).

[0033] The flow rate of engine gas supplied to the first inlet of the ejector 4 can be regulated by a control valve 7 which can be controlled by the discharge pressure measured at the outlet of the ejector 4 by a pressure sensor 9. This sensor 9 can also be located directly at the level of or on the tank 2

[0034] Alternatively or in combination, a temperature sensor 8 may be provided at the outlet of the ejector 4 to allow control of the temperature of the flow supplied to the reservoir 2 by controlling the regulating valve 10 located upstream of the second inlet of the ejector 4 and / or by controlling a flow regulating valve 11 arranged on the injection line 5 preferably in parallel with the ejector 4.

[0035] As schematically illustrated in dotted lines, the installation 1 may include a heat exchanger 12 for heating the fluid (liquid) flow admitted to the second suction inlet of the ejector 4. This optional heat exchanger 12 may be an atmospheric exchanger located at the suction of the ejector and may ensure vaporization of the liquid for better operation, depending for example on the sizing of the ejector 4.

[0036] In addition, the installation 1 may include a flow meter at the outlet of the ejector 4 on the injection line 5. This flow meter (not shown) can allow the discharge flow rate of the ejector to be determined precisely (for the purpose of sizing it for example).

[0037] The ejector device 4 and the circuitry and all or part of the associated components can be housed inside a casing or frame shown schematically in dotted lines. This assembly can be integrated on a mobile support independent and separate from the tank or semi-trailer, or can be housed directly on the tank, storage unit, or semi-trailer.

[0038] The pressurization device may further include an additional tank pressurization unit (“PBU”) comprising, for example, an atmospheric heat exchanger that can be positioned under the tank and configured to cooperate, by for example simultaneously with ejector 4 to allow increasing the flow rate of fluid drawn from tank 2. This additional tank pressurization device (“PBU”) may include a loop allowing liquid to be drawn, vaporized in the external exchanger and returned to tank 2. This can be used simultaneously or sequentially with the system with ejector 4.

Claims

Demands

1. Installation for the storage and distribution of cryogenic fluid, for example liquid hydrogen, comprising a cryogenic tank (2) equipped with a withdrawal line (3) configured to permit the withdrawal of liquid from the tank (2) and a pressurization device for the tank (2) comprising an injection line (5) connected to the tank (2) and configured to permit the injection of fluid into the tank (2) to pressurize the tank (2), for example to maintain the pressure in the tank (2) during a withdrawal of liquid, characterized in that the pressurization device comprises an ejector (4) disposed on the injection line (5), the ejector (4) having a first inlet for motive gas connected to a source (6) of pressurized gas from the installation (1), a second suction inlet connected to another source of fluid preferably liquefied, the outlet of the ejector (4) being connected to the tank (2).

2. Installation according to the preceding claim characterized in that the second suction inlet of the ejector (4) is connected to the draw-off line (3).

3. Installation according to the preceding claim, characterized in that it comprises a valve (10), for example an isolation valve and / or a pressure and / or flow control valve for the fluid admitted into the second suction inlet of the ejector (4).

4. Installation according to any one of the preceding claims characterized in that the source (6) of pressurized gas comprises at least one pressurized gas storage preferably equipped with a pressure and / or flow regulator (7).

5. Installation according to the preceding claim characterized in that it comprises a pressure sensor (9) of the flow at the outlet of the ejector (4) and / or in the reservoir (2).

6. Installation according to the preceding claim characterized in that the pressure regulator (7) is configured to regulate the pressure and / or flow of the engine gas according to the measurement of the pressure sensor (9).

7. Installation according to any one of the preceding claims characterized in that it comprises a flow temperature sensor (8) disposed at the outlet of the ejector (4).

8. Installation according to any one of the preceding claims characterized in that the injection line (5) includes a pressure and / or flow control valve (11) arranged in parallel with the ejector (4).

9. Installation according to claims 7 and 8, characterized in that the valve (11) located in parallel with the ejector is configured to regulate the temperature of the fluid downstream of the ejector (4) as a function of the measurement of the temperature sensor (8).

10. Installation according to claims 3 and 7, characterized in that the valve (10) for regulating the pressure and / or flow of fluid admitted into the second suction inlet of the ejector (4) is configured to regulate the pressure and / or flow according to the measurement of the temperature sensor (8).

11. Installation according to any one of the preceding claims, characterized in that it comprises a heat exchanger (12) for reheating the fluid flow admitted to the second suction inlet of the ejector (4).

12. Installation according to any one of the preceding claims, characterized in that the pressurization device further comprises an additional tank pressurization element comprising, for example, an atmospheric exchanger positioned under the tank configured to cooperate, for example, simultaneously with the ejector (4) to enable an increase in the flow rate of the fluid withdrawn from the tank (2).