Device and method for transferring cryogenic fluid

Abstract

The invention relates to a cryogenic fluid transfer device comprising a first reservoir (2) storing a cryogenic fluid, a second receiving cryogenic reservoir (3), a fluid transfer circuit connecting the reservoirs and comprising a first pipe (4) connecting the upper parts of the first (2) and second (3) reservoirs with a first valve (5), a second pipe (6) connecting the lower part of the first (2) reservoir to the second (3) reservoir with a pump (7), the pump (7) and the first valve (5) being configured to ensure fluid connection of the upper parts of the first (2) and second (3) reservoirs, the first pipe (4) comprising a bypass portion (9) equipped with a heater (13) and a set of valve(s) (10) configured to allow modification of the temperature of the gas flow transferred from the second (3) reservoir to the first (2) reservoir via the first pipe (4). (Shorthand figure: Fig. 1)

Description

Title of the invention: Device and method for transferring cryogenic fluid

[0001] The invention relates to a device and a method for transferring cryogenic fluid.

[0002] The invention relates more particularly to a cryogenic fluid transfer device comprising a first cryogenic fluid distribution tank, said first tank storing a cryogenic fluid with a lower liquid phase and an upper gaseous phase, a second cryogenic receiving tank housing a cryogenic fluid comprising a lower liquid phase and an upper gaseous phase, a fluid transfer circuit connecting the first and second tanks, the transfer circuit comprising a first conduit connecting the upper parts of the first and second tanks and comprising at least one first valve, the transfer circuit comprising a second conduit connecting the lower part of the first tank to the second tank, the second transfer conduit comprising a pump comprising an inlet connected to the first tank and an outlet connected to the second tank,The pump and the first valve are configured to ensure fluid connection between the upper parts of the first and second tanks by opening the first valve, for example, before or during a transfer of liquid from the first tank to the second tank by the pump.

[0003] The invention applies in particular to the delivery of liquefied hydrogen.

[0004] Such a device is described in document EP4153900A1. Other devices are described in EP3690303A1 or FR3041624A1.

[0005] To refill a receiving cryogenic tank, the cryogenic liquid must be transferred from a semi-trailer to the receiving tank by pressure differential. Generally, the receiving tank is at a higher pressure than the pressure in the delivery trailer's tank.

[0006] In a known solution, an atmospheric heater is generally placed under the delivery semi-trailer to allow pressurization and transfer of its contents to a customer tank.

[0007] This ambient heating system, however, has some drawbacks. For example, its performance is difficult to control because it is dependent on weather conditions (temperature, wind, humidity).

[0008] This generates stratification in the gas headspace of the delivery tank (increasing the gas temperature). This tends to heat the liquid hydrogen delivered to the customer (especially in the case of multiple deliveries). Thus, the delivered hydrogen is of lower quality.

[0009] This solution also requires pressurizing the delivery tank before starting the transfer. This can take from 15 to 60 minutes depending on the level in the tank.

[0010] In addition, the atmospheric heater consumes a useful cryogenic liquid and regulation requires manual operations by the driver, including priming management.

[0011] This can also create a cryogenic cloud and condensation of liquid oxygen under the delivery tank. Finally, this solution does not allow for the recycling of the vaporization gases generated in the receiving tank ("boil-off").

[0012] One object of the present invention is to overcome all or part of the disadvantages of the prior art noted above.

[0013] To this end, the device according to the invention, which also conforms to the generic definition given in the preamble above, is essentially characterized in that the first pipe includes a bypass portion equipped with a heater and a set of valve(s) configured to allow modification of the temperature of the gas flow transferred from the second tank to the first tank via the first pipe.

[0014] Furthermore, embodiments of the invention may include one or more of the following features: - the bypass section comprises two ends connected respectively on either side of the first valve, - The bypass section includes a second flow control valve, - The device includes a temperature sensor measuring the temperature in the first pipe between the bypass section and the first tank. - the device includes an electronic control unit for data acquisition and processing, the control unit being configured to receive a measurement signal from the temperature sensor and to control the second flow control valve based on this measurement, - the second pipe includes an end connecting the lower part of the first tank to the lower part of the second tank, - the second pipe includes an end connecting the lower part of the first tank to the upper part of the second tank, - at least part of the first pipe is thermally insulated, for example via vacuum insulation.

[0015] The invention also relates to a method for transferring cryogenic fluid between a first cryogenic fluid distribution reservoir and a second cryogenic reservoir of a device conforming to any one of the characteristics above or below, the method comprising a step of transferring liquid from the first reservoir to the second reservoir via the pump and, prior to and / or simultaneously with this liquid transfer step, a fluid connection of the upper parts of the first and second reservoirs by opening the first valve.

[0016] According to other possible features: - the process includes a step of circulating, in the first pipeline, a flow of gas taken from the second reservoir, - at least part of the gas flow put into circulation in the first pipe is preheated in the bypass section, - The gas flow circulating in the first pipe is transferred to the first tank at a predetermined temperature, controlled by regulating the proportion of the gas flow allowed to pass through the bypass section. - during the liquid transfer step from the first tank to the second tank by the pump, the liquid is transferred into the lower liquid part and / or the upper gaseous part of the second tank.

[0017] 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.

[0018] Other features and advantages will become apparent from the following description, given with reference to the figures in which: Brief description of the figures

[0019] 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:

[0020] [Fig. 1] a schematic and partial view of an example of the structure and operation of a transfer device according to the invention. Detailed description

[0021] In all figures, the same references refer to the same elements.

[0022] 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.

[0023] As illustrated, the cryogenic fluid transfer device 1 comprises a first cryogenic fluid distribution tank 2, for example a mobile tank 2 mounted on a semi-trailer. Conventionally, the first tank 2 stores a cryogenic fluid, for example hydrogen, with a liquid phase in the lower part and a gaseous phase in the upper part.

[0024] Device 1 includes a second cryogenic reservoir 3 for receiving the same fluid, for example, a fixed reservoir containing or intended to contain a cryogenic fluid with a liquid phase in its lower part and a gaseous phase in its upper part. Device 1 includes a fluid transfer circuit adapted to connect the first 2 and the second 3 reservoirs. This transfer circuit includes a first conduit 4 having two ends connected respectively to the upper parts of the first 2 and the second 3 reservoirs. This first conduit 4, comprising at least one valve 5 (and for example, preferably at least two valves in series), and having one end connected to the second 3 reservoir, includes detachable connecting elements to allow successive connections to various reservoirs to be supplied with fluid.

[0025] The transfer circuit includes a second 6-pipe adapted to connect the lower part of the first 2-tank to the second 3-tank (at the lower and / or upper part). In the example shown, the second 6-pipe has two downstream ends connected respectively to the lower and upper parts of the second 3-tank.

[0026] The second transfer line 6 comprises a pump 7 having an inlet connected to the first reservoir 2 and an outlet connected to the second reservoir 3. This second line 6 preferably includes a set of valve(s) for interrupting or allowing the transfer of liquid flow from the first reservoir 2 to the second reservoir 3. As before, at least at its downstream end(s) connected to the second reservoir 3, the second line 6 includes detachable connecting members to allow successive connections to various reservoirs to be supplied.

[0027] The pump 7 and the valve assembly 5 of the first line 4 are configured to ensure fluid connection of the upper parts (gaseous phases) of the first 2 and second 3 tanks during and / or before a transfer of liquid from the first tank 2 to the second tank 3 by the pump 7.

[0028] Connecting the gas heads of the two tanks 2 and 3 during pumping improves the thermal and hydraulic efficiency of the fluid transfer in an optimized sequential procedure. This makes the use of an atmospheric heater on the first tank 2 optional and allows for the utilization of the gas head of the second tank 3, while improving the quality of the delivered molecule and the volumetric yields of the deliveries.

[0029] Thus, while the pump 7 circulates liquid from the first reservoir 2 to the second reservoir 3, the second line 6 allows the "excess" gas present in the second reservoir 3 to circulate by pressure differential to the first reservoir 2, in particular to fill the volume left free by the withdrawal of liquid.

[0030] As illustrated, preferably, at least a portion of the first pipe 4 is thermally insulated, for example via vacuum insulation. This provides numerous advantages.

[0031] The recovered gas is thus kept cold and does not increase the temperature of the liquid hydrogen in the first tank 2. This further limits heat input during deliveries and reduces evaporation losses throughout the supply chain. The pressure remains low in the first tank 2 during operations because only a small amount of heat is introduced during delivery.

[0032] According to an advantageous feature, the first line 4 includes a bypass portion 9 equipped with a heater 13 and a set of valve(s) 10 configured to allow modification of the temperature of the gas flow transferred from the second 3 tank to the first 2 tank via the first line 4.

[0033] That is to say, at least a part of the gas flow passing from the second tank 3 to the first tank 2 via the first pipe 4 can be diverted into the bypass portion 9 to be heated there by the heater 13 before being sent back downstream into the first pipe 4 before supplying the first tank 2. The heater may include a heat exchanger for example providing hot power.

[0034] As illustrated, the bypass portion 9 can include two ends connected respectively on either side of the first valve 5. The bypass portion 9 is for example a pipe forming a bypass of the first valve.

[0035] As illustrated, the bypass portion 9 may include a second valve 10, preferably with progressive opening to allow flow control. This makes it possible to regulate the proportion of the gas flow that passes through the bypass portion 9 to be heated.

[0036] The installation preferably includes a temperature sensor 11 measuring the temperature in the first pipe, for example between the bypass portion 9 and the first 2 tank, i.e. in the downstream part of the first pipe which receives the mixture or heated gas and unheated gas.

[0037] As illustrated, the installation may include or be connected to an electronic control unit 12 for data acquisition and processing (comprising, for example, a microprocessor). This control unit 2 may be configured to receive the measurement signal from the temperature sensor 1) and to control, based on this signal, the second flow control valve 10.

[0038] Controlling the temperature of the gas transferred from the second tank 3 to the first tank 2 ensures a relatively stable pressure in tanks 2, 3 during deliveries.

[0039] The temperature of the supplied gas can be monitored by the temperature sensor 11. A predefined optimal temperature for the return gas can be set. This can be achieved via the second valve 10. For example, this temperature can be set to improve the efficiency of the supply chain, depending on the type of supply chain.

[0040] Thanks to this bypass portion 9, in addition to the possibility of controlling the temperature of the vaporization gas transferred in particular to the first tank 2, the installation 1 can carry out a purge of all or part of the transfer circuit and in particular of the first line 4.

[0041] For example, before the liquid and gas transfer operation between tanks 2, 3, the installation can use the gas allowed to circulate in the bypass portion 9 to purge all or part of the lines, for example with hydrogen from the second tank 3 which is heated to a relatively hot temperature (for example between -50°C and 30°C).

[0042] The gaseous hydrogen supplied by the second tank 3 can be fully heated for initial purges to consume as little gas as possible while maintaining a high volumetric flow rate for good purge efficiency.

[0043] Similarly, this gas heated in the bypass portion 9 can be used for a purging operation of all or part of the circuit after a delivery of liquid.

[0044] The gas withdrawn from the second tank 3 can be fully reheated to consume as little gas as possible while maintaining a high volumetric flow rate for good purging efficiency.

[0045] In the case of a delivery of liquefied gas such as hydrogen, for example, the first tank 2 can arrive at the site of the second tank 3. The first tank 2 has, for example, an internal pressure between 1 and 6 bar. The operator can connect the two tanks 2 and 3 with the first 4 and second 6 pipelines. During this connection, the valve assemblies are closed.

[0046] After the inerting and / or purging and / or cooling operations of the pipes 4, 6, a pressure equalization is carried out between the two reservoirs 2, 3 via, in particular, the opening of the first and / or second valve 10

[0047] Preferably when the pressure difference between the two tanks 2, 3 is reduced to close to 0 bar (or to a determined value less than 1 bar for example), the pump 7 can then be started.

[0048] As illustrated, the second 3 tank may include a tank 3 pressurization system 8 comprising for example a pipe connecting the lower and upper parts of the tank 3 and equipped with a heater and a set of valve(s).

[0049] This pressurization of the second and reservoir 3 and / or of the first reservoir can be carried out simultaneously with a step of transferring liquid from the first reservoir 2 to the second reservoir 3 via the pump 7.

Claims

Demands

1. A cryogenic fluid transfer device comprising a first cryogenic fluid distribution tank (2), said first tank (2) storing a cryogenic fluid having a lower liquid phase and an upper gaseous phase, a second receiving cryogenic tank (3) housing a cryogenic fluid comprising a lower liquid phase and an upper gaseous phase, a fluid transfer circuit connecting the first (2) and the second (3) tank, the transfer circuit comprising a first conduit (4) connecting the upper parts of the first (2) and second (3) tanks and comprising at least one first valve (5), the transfer circuit comprising a second conduit (6) connecting the lower part of the first (2) tank to the second (3) tank, the second (6) transfer conduit comprising a pump (7) comprising an inlet connected to the first (2) tank and an outlet connected to the second (3) tank,the pump (7) and the first valve (5) being configured to ensure fluid connection of the upper parts of the first (2) and second (3) tanks by opening the first valve (5), for example before or during a transfer of liquid from the first tank (2) to the second tank (3) by the pump (7), characterized in that the first line (4) comprises a bypass portion (9) equipped with a heater (13) and a set of valve(s) (10) configured to allow modification of the temperature of the gas flow transferred from the second (3) tank to the first (2) tank via the first line (4).

2. Device according to claim 1, characterized in that the bypass portion (9) comprises two ends connected respectively on either side of the first valve (5).

3. Device according to claim 1 or 2, characterized in that the bypass portion (9) comprises a second flow control valve (10).

4. Device according to any one of claims 1 to 3, characterized in that it comprises a temperature sensor (11) measuring the temperature in the first pipe (4) between bypass portion (9) and the first (2) reservoir.

5. Device according to claim 4, characterized in that it comprises an electronic control element (12) with acquisition and data processing, the control unit (12) being configured to receive a measurement signal from the temperature sensor (11) and to control the second flow control valve (10) according to this measurement.

6. Device according to any one of the preceding claims, characterized in that the second (6) conduit comprises an end connecting the lower part of the first (2) reservoir to the lower part of the second (3) reservoir.

7. Device according to any one of the preceding claims, characterized in that the second (6) conduit comprises an end connecting the lower part of the first (2) reservoir to the upper part of the second (3) reservoir.

8. Device according to any one of the preceding claims, characterized in that at least a part of the first conduit (4) is thermally insulated, for example via vacuum insulation.

9. Method for transferring cryogenic fluid between a first cryogenic fluid distribution tank (2) and a second cryogenic tank of a device according to any one of the preceding claims, the method comprising a step of transferring liquid from the first tank (2) to the second tank (3) via the pump (7) and, prior to and / or simultaneously with this liquid transfer step, a fluid connection of the upper parts of the first (2) and second (3) tanks by opening the first valve (5).

10. The method according to the preceding claim characterized in that it comprises a step of putting into circulation, in the first pipe (4), a flow of gas taken from the second reservoir (3).

11. A method according to the preceding claim characterized in that at least a part of the gas flow put into circulation in the first pipe (4) is preheated in the bypass portion (9).

12. A method according to any one of claims 10 or 11, characterized in that the gas flow put into circulation in the first pipe (4) is transferred into the first reservoir (2) with a determined temperature controlled by regulating the proportion of the gas flow admitted to pass through the bypass portion (9).

13. A method according to any one of claims 9 to 12, characterized in that during the liquid transfer step from the first reservoir (2) to the second reservoir (3) by the pump (7), the liquid is transferred into the lower liquid part and / or into the upper gaseous part of the second (3) reservoir.

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