Device, installation and method for maintaining the cold of a liquefied gas storage facility

Abstract

The invention relates to a device and method for keeping a liquefied gas storage (2) cold, comprising a cryogenic refrigerator (3), a subcooling circuit (4, 5) comprising a suction end (4) intended to be housed in a liquefied gas storage (2), a heat exchanger (6) ensuring a heat exchange between the suction subcooling circuit (4, 5) and the refrigerator (3), the subcooling circuit (4, 5) comprising at least one injection end (5, 7) configured to inject into the storage (2) the fluid cooled in the heat exchanger (6), the device (1) further comprising a vaporization gas recovery pipe (8) having an upstream end intended to be connected to the storage (2) to recover vaporization gas, the recovery pipe (8) comprising a downstream end (18) intended to be connected to a consumer,the device (1) comprising a bypass pipe (9) and a set of valve(s) (10) configured to allow the transfer of vaporization gas from the recovery pipe (8) to the subcooling circuit (4, 5), the bypass pipe (9) having a first end connected to the recovery pipe (8) and a second end connected to the subcooling circuit (4, 5), the second end of the bypass pipe (9) being connected to the subcooling circuit (4, 5) upstream of the heat exchanger (6) Abstract figure: Fig. 1,

Description

Title of the invention: Device, installation and method for keeping a liquefied gas storage facility cold

[0001] The invention relates to a device, an installation and a method for keeping a liquefied gas storage facility cold.

[0002] The invention relates in particular to a device and a method for maintaining the cold and / or pressure of a storage facility for liquefied gas, for example liquefied natural gas.

[0003] The invention relates more particularly to a device for keeping a liquefied gas storage, for example liquefied natural gas, cold, comprising a cryogenic refrigerator, a subcooling circuit comprising a set of pipe(s), the subcooling circuit comprising a suction end intended to be housed in a lower portion of a liquefied gas storage configured to suck in liquefied gas, a heat exchanger ensuring a heat exchange between the sucked subcooling circuit and the refrigerator, the subcooling circuit comprising at least one injection end configured to inject into the storage the fluid cooled in the heat exchanger, the device further comprising a vaporization gas recovery pipe having an upstream end intended to be connected to an upper portion of the storage to recover vaporization gas,the recovery line comprising a downstream end intended to be connected to a consumer of the vaporization gas, for example a burner and / or an engine, the device comprising a bypass line and a set of valve(s) configured to allow the transfer of vaporization gas from the recovery line to the subcooling circuit, the bypass line having a first end connected to the recovery line and a second end connected to the subcooling circuit.

[0004] The vaporization gases of a cryogenic fluid in a storage facility can be recovered by direct reliquefaction. The solution consists of cryogenic compression of these evaporations, bringing them to room temperature and then sending them to a liquefier.

[0005] Another functionality consists of the reliquefaction of the evaporation gases carried out by transferring cold power from a refrigerator to the cryogenic liquid by subcooling it, which is then returned to storage.

[0006] Document WO2019020742 A1 describes an installation ensuring the treatment of vaporization gas or the cooling of liquefied gas.

[0007] The cooling exchanger may be subject to fouling due to the precision pitation of the heavier components (the more it cools, the less solubility there is). Indeed, the cryogenic fluid is not necessarily a pure compound and may be in the form of a mixture. Thus, some of the components of the mixture may be solidified during subcooling. These solid particles can foul the refrigerator's exchanger and thus degrade the system's performance.

[0008] Various solutions are known to absorb or limit this fouling. However, these solutions are not satisfactory for both treating vaporization gases and / or sub-cooling a stored liquefied gas.

[0009] An aim of the present invention is to overcome all or part of the drawbacks of the prior art noted above.

[0010] To this end, the device according to the invention, moreover in accordance with the generic definition given in the preamble above, is essentially characterized in that the second end of the bypass pipe is connected to the sub-cooling circuit upstream of the heat exchanger.

[0011] Furthermore, embodiments of the invention may include one or more of the following features: - the valve assembly(s) includes a flow control valve on the bypass line, - the flow control valve is a pilot-operated valve configured to transfer a flow of vaporization gas to the sub-cooling circuit to increase the temperature of the fluid entering the heat exchanger by a determined value, for example between 5 and 25°C, - the flow control valve is a pilot-operated valve configured to transfer a flow of vaporization gas to the sub-cooling circuit to maintain the temperature of the fluid entering the heat exchanger below the saturation temperature of the liquefied gas, - the flow control valve is a pilot-operated valve configured to transfer a flow of vaporization gas to the sub-cooling circuit to maintain the temperature of the fluid leaving the heat exchanger above a determined value, for example above -160°C and / or at a value equal to the temperature of the liquefied gas in the storage and / or at a value equal to the temperature of the liquefied gas drawn into the suction end, - the recovery line comprising at least one compressor, the first end of the bypass line is connected to the recovery line downstream of the compressor, - the recovery line includes several compressors in series, the first end of the bypass line is connected to the recovery line downstream of an intermediate compressor, i.e. upstream of the last compressor in series, - the compressor is configured to supply a gas flow to the bypass line having a pressure greater than the pressure of the liquid drawn at the suction end and supplied to the subcooling circuit, - the device comprises a member for mixing the vaporization gas in the subcooling circuit, the mixing member being located for example at the junction between the second end of the bypass pipe and the subcooling circuit, the mixing member comprising at least one of: an indirect heat exchanger with injection, a gas injector in liquid, a static mixer, an upstream injector, a filtration system, a condenser pot with bulk or structured packing, - the bypass line comprises a pre-cooling member in heat exchange with the vaporization gas transferred to the sub-cooling circuit, the pre-cooling member being configured for example to cool the flow of vaporization gas transferred to an intermediate temperature between the temperature of the vaporization gas of the recovery line and the temperature of the liquefied gas, - the recovery line comprises a heat exchanger allowing heat exchange between the vaporization gas from the recovery line and the vaporization gas from the bypass line, - the bypass line includes a divert line and set of valve(s) for controlling the flow of vaporization gas from the bypass line allowed to circulate in the heat exchanger of the recovery line, - the suction end includes a suction pump.

[0012] The invention also relates to a storage facility for liquefied gas, for example liquefied natural gas, for example a ship for transporting liquefied gas, comprising at least one liquefied gas storage facility and a device for keeping the fluid contained in the storage facility cold, the cold-keeping device conforming to any one of the preceding or following characteristics.

[0013] The invention also relates to a method for keeping a liquefied gas storage cold using a device according to any one of the preceding claims comprising pumping liquefied gas into a cryogenic storage, cooling the pumped liquefied gas and reinjecting the cooled liquefied gas into the storage, the method comprising recovering vaporization gas from the storage. and a step of injecting and mixing vaporization gas into the pumped liquefied gas before it is cooled.

[0014] This makes it possible to increase the temperature of the fluid at the inlet of the subcooling circuit by injecting vaporization gas in order to prevent the crystallization of heavy hydrocarbons in the heat exchanger 6 since the subcooler (refrigerator) is preferably configured to never lower the temperature of the fluid to be cooled lower than the initial temperature of the subcooled liquid.

[0015] According to other possible features, the injection and mixing step is configured to raise the temperature of the pumped liquefied gas before cooling by a determined value and / or to maintain the temperature of the cooled liquefied gas below a determined threshold and / or at the level of the temperature of the liquefied gas in the storage or pumped.

[0016] 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.

[0017] Other features and advantages will appear on reading the description below, given with reference to the figures in which: Brief description of the figures

[0018] The invention will be better understood on reading the following description given solely by way of example and with reference to the appended drawings in which:

[0019] [Fig-1] is a schematic view illustrating an example of structure and function operation of an installation according to a first embodiment of the invention,

[0020] [Fig.2] is a schematic view illustrating an example of structure and function operation of an installation according to a second embodiment of the invention,

[0021] [Fig.3] is a schematic view illustrating an example of structure and function operation of an installation according to a third embodiment of the invention,

[0022] [Fig.4] is a schematic view illustrating an example of structure and function operation of an installation according to a fourth embodiment of the invention. Detailed description

[0023] In all the figures, the same references refer to the same elements.

[0024] 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. Single features of different embodiments may also be combined and / or interchanged to provide other embodiments.

[0025] The illustrated device 1 for maintaining the cold of a storage 2 of liquefied gas can ensure the maintenance of the cold and / or the maintenance of the pressure for example of a tank of liquefied natural gas, for example on a ship.

[0026] This device 1 comprises a cryogenic refrigerator 3 and a sub-cooling circuit 4, 5 comprising a set of pipe(s).

[0027] The subcooling circuit 4, 5 comprises at least one suction end 4 intended to be housed in a lower portion of a liquefied gas storage 2 and configured to suck in liquefied gas. As illustrated, the suction end 4 preferably comprises a suction pump 17.

[0028] The sub-cooling circuit 4, 5 further comprises a heat exchanger 6 ensuring a heat exchange between the suction sub-cooling circuit 4, 5 and the refrigerator 3. Preferably, this heat exchanger 6 is located outside the storage 2.

[0029] The refrigerator may in particular comprise or consist of a cryogenic refrigerator or liquefier in which a cycle gas (helium, nitrogen, or other pure gas or mixture) undergoes a thermodynamic cycle (compression, cooling, expansion, reheating) producing a cold power at at least one end which can be transferred by heat exchange. For example, the refrigerator is of the reverse Brayton cycle type and more particularly of the Turbo Brayton type using turbomachines (coupling on the same axis of at least one compressor and one turbine on bearings and magnetic motor). The sub-cooling circuit 4, 5 comprises at least one injection end 5, 7 configured to inject into the storage 2 the fluid cooled in the heat exchanger 6.

[0030] In the example illustrated, the sub-cooling circuit 4, 5 comprises two injection ends 5, 7. A first end opens into the upper part of the storage in the form of nozzle(s) to allow the cooled fluid to be injected into the gaseous phase of the storage 2 in order to recondense vapors and / or control the pressure in the storage 2.

[0031] A second end opens, for example, into the lower part of the storage 2 to cool the liquid phase.

[0032] According to the invention, the ejector at the bottom of storage 2 (injector) preferably returns the liquefied gas and the mixture to the liquid phase. The injected liquid is no longer sub-cooled but at the same temperature as the liquid in storage 2.

[0033] The device 1 further comprises a pipe 8 for recovering the vaporization gases having an upstream end connected to an upper portion of the storage 2 configured to recover vaporization gas. The recovery pipe 8 preferably comprises at least one member 11 for compressing the recovered vaporization gas (typically at least one compressor). The recovery pipe 8 comprises downstream at least one downstream end 18 intended to be connected to a consumer of the vaporization gas, for example a burner and / or an engine. This compression 11 allows to maintain a constant pressure in storage 2 and to supply gas to the engines, the excess combustible vaporization gas can be directed towards a combustion torch for example.

[0034] The device 1 comprises a bypass pipe 9 and a set of valve(s) 10 configured to allow the transfer of vaporization gas from the recovery pipe 8 to the subcooling circuit 4, 5. This bypass pipe 9 has a first end connected to the recovery pipe 8, preferably downstream of the compression member 11, and a second downstream end connected to the subcooling circuit 4, 5, upstream of the heat exchanger 6. For example, the set of valve(s) comprises a flow control valve 10 on the bypass pipe 9.

[0035] This makes it possible to prevent fouling phenomena by injecting vaporization gas taken, for example at the compression outlet, for example at ambient temperature.

[0036] This makes it possible to inject relatively hotter gas upstream of the cooling by the refrigerator / liquefier. This gas supplied by the bypass line 9 can be mixed within a flow of cryogenic liquid taken from the storage via the suction line 4 of the sub-cooling circuit.

[0037] The gas taken and mixed with the liquid flow is preferably at a pressure at least higher than the discharge pressure of the liquid suction pump 17 located at the bottom of the cryogenic fluid storage 2.

[0038] As illustrated, the device 1 may comprise a member 12 for mixing the vaporization gas in the subcooling circuit 4, 5. This mixing member 12 configured to achieve partial or total mixing of the gas in the liquid is located for example at the junction between the downstream end of the bypass pipe 9 and the subcooling circuit 4, 5. This mixing member 12 comprises for example at least one of: an indirect heat exchanger with injection, a gas injector in liquid, a static mixer, an upstream injector, a filtration system, a condenser pot with bulk or structured packing or any other suitable member or combination of several of these technologies.

[0039] The flow control valve 10 is for example a piloted valve which can be configured to transfer a flow of vaporization gas to the sub-cooling circuit 4, 5 to increase the temperature of the fluid which enters the heat exchanger 6 by a determined value, for example between 5 and 25°C.

[0040] For example, the flow control valve 10 may be configured to transfer a flow of vaporization gas to the subcooling circuit 4, 5 to maintain the temperature of the fluid entering the heat exchanger 6 below the saturation temperature of the liquefied gas. This allows the mixture to remain in liquid phase. It is possible to provide a temperature margin, for example 2°C below saturation, to ensure that no gas bubbles enter the heat exchanger 6.

[0041] The regulation of the flow rate of mixed gas upstream of the heat exchanger 6 can be carried out for example by calculating a saturation temperature of the fluid (the bubble point temperature being the temperature at which the first vapor bubble is created).

[0042] This saturation temperature can be based on a typical composition of the stored fluid.

[0043] This saturation temperature can possibly be adjusted according to a correlation via a pressure parameter for example. It is thus possible to control the injection of vaporization gas by the flow control valve 10 until obtaining as outlet temperature of the mixer 10 a temperature with a safety deviation from the saturation temperature (temperature at the outlet of mixer 12 being equal to the saturation temperature of the fluid minus the safety margin).

[0044] Alternatively or in combination, the flow control valve 10 can be controlled to maintain the temperature of the fluid leaving the heat exchanger 6 above a determined value, for example above -160°C and / or at a value equal to the temperature of the liquefied gas in the storage and / or at a value equal to the temperature of the liquefied gas sucked into the suction end 4.

[0045] For example, it is possible to measure the temperature of the fluid at the outlet of the pump 17 and / or in the storage 2. The flow rate can be adjusted by the flow control valve 10 so that the temperature of the fluid at the outlet of the cooling exchanger 6 is equal to the temperature of the liquid in the storage 2.

[0046] Increasing the pressure of the pumped liquid raises its saturation point. This has the effect of allowing total or partial solubility of the gas in the cryogenic liquid upstream of the liquefier.

[0047] This dissolution of the vaporization gas in the liquid is done by raising the temperature of the cryogenic liquid.

[0048] The quantity of gas injected via the bypass pipe 9 can therefore allow the choice of adjusting a temperature at the inlet and / or outlet of the refrigerator (at the inlet and / or outlet of the heat exchanger 6). This control can be carried out by a simple flow control valve 10. The temperature of the fluid to be cooled can therefore be measured at the inlet and / or outlet of the heat exchanger 6 by one or more appropriate temperature sensors 19.

[0049] The refrigerator 3 reduces the temperature of the liquid or gas / liquid mixture obtained before returning it to the storage 2 (at the bottom of the storage and / or in the upper part via one or more ramps or nozzle(s)).

[0050] The temperature of the fluid leaving the cooling heat exchanger 6 is thus controlled such that it does not generate any solidification or less solidification within the heat exchanger 6. This temperature is therefore at least equal to the initial temperature of the cryogenic liquid pumped into the storage 2. The quantity of gas injected via the bypass pipe 9 can also make it possible to regulate the pressure drop within the heat exchanger 6.

[0051] The device 1 can also be used in “mixed” mode, that is to say by combining on the one hand, a liquefaction of the recovered and compressed and reinjected vaporization gas and, on the other hand, a partial sub-cooling of the cryogenic liquid before returning to storage 2.

[0052] The device 1 can alternatively operate in subcooling mode in which the injection of relatively hotter vaporization gas is stopped via the bypass line 9 (valve 10 closed) or in liquefaction mode by injection of vaporization gas via the bypass line 9 (valve 10 open).

[0053] This allows a flexible system offering both operating modes. The switch from one mode to the other can be decided for example arbitrarily by an operator according to the risk of blockage of the heat exchanger 6 and / or automatically via detection or prediction (intelligence) detecting the occurrence of a blockage (increase in the pressure difference at the terminals of the heat exchanger 6, drop in temperatures, etc.).

[0054] The embodiment of [Fig.2] differs from that of [Fig.l] in that the bypass pipe 9 comprises a pre-cooling member 13 in heat exchange with the vaporization gas transferred to the sub-cooling circuit 4, 5. This pre-cooling member 13 can be configured for example to cool the flow of vaporization gas transferred to an intermediate temperature between the temperature of the vaporization gas from the recovery pipe 8 and the temperature of the liquefied gas pumped into the storage 2.

[0055] This makes it possible to optimize or increase the quantity of injectable compressed gas via the external pre-cooling 13 having an intermediate temperature between the temperature of the cryogenic liquid and the ambient temperature. For example, this pre-cooling member 13 may comprise or consist of at least one of: a refrigeration cycle using a refrigerant fluid, a compression system and an expansion system of the valve, orifice or turbine type.

[0056] The embodiment of [Fig. 3] differs from that of [Fig. 1] in that the recovery pipe 8 comprises a heat exchanger 16 allowing a heat exchange between the vaporization gas of the recovery pipe 8 and the vaporization gas of the bypass pipe 9. For example, the bypass pipe 9 comprises a divert pipe 14 and set of valve(s) 15 allowing control the flow of vaporization gas from the bypass line 9 admitted to circulate in the heat exchanger 16 of the recovery line 8.

[0057] This makes it possible to carry out pre-cooling of the vaporization gas by recovering cold power from the vaporization gas taken from storage 2, upstream of compression.

[0058] One or more regulating valves can be used to control, as desired, the temperature of the gas entering the compression member, the temperature of the fluid entering the refrigerator (entering the heat exchanger 6) or the temperature of the fluid leaving the heat exchanger 6. This control can be carried out to maximize the recovered cold power while ensuring proper operation of the compression 11 and preventing the formation of solids in the heat exchanger 6 of the refrigerator 3. This makes it possible to optimize / increase the quantity of compressed vaporization gas injectable via the bypass pipe 9.

[0059] The embodiment of [Fig.4] differs from that of [Fig.l] in that the recovery pipe 8 comprises several compressors 11 in series and the first upstream end of the bypass pipe 9 is connected to the recovery pipe 8 downstream of an intermediate compressor 11, i.e. upstream of the last compressor in series.

[0060] That is to say that the vaporization gas is recovered at the outlet of the first or a subsequent compression stage rather than at the outlet of the last compressor. The pressure of the recovered gas is however preferably higher than the pressure of the liquid pumped into the storage with which it is mixed. The temperature of this vaporization gas at an intermediate compression stage is relatively colder than at the outlet of the last compressor. The quantity of vaporization gas which can be mixed with the liquid may thus be greater than in the embodiment of [Fig.l]. This embodiment may also replace the pre-cooling member 13 of the embodiment of [Fig.2].

[0061] The device thus allows optimal management of vaporization gases and cold maintenance (subcooling in particular) of a liquefied gas storage, for example methane, without generating a solid deposit in the cooling heat exchanger 6. The invention makes it possible to avoid or limit a degradation in the performance of the device.

[0062] The vaporization gas injected upstream of the heat exchanger 6 of the refrigerator 3 heats the liquid before it is cooled. The refrigerator 3 then brings this mixture back, for example, to the temperature of the fluid in the storage 2.

[0063] The vaporization gas taken 9 and mixed is totally or partially liquefied on its return to the storage 2. The coldest temperature reached by the fluid in the heat exchanger 6 does not allow solidification conditions to be reached.

[0064] The solution described makes it possible to convert by adaptation a conventional sub-cooling system into a direct reliquefier in the event of the presence of pollutants such as heavy hydrocarbons. The solution makes it possible to prevent the phenomena of crystallization of heavy hydrocarbons during cooling.

Claims

Claims

1. Device for keeping a storage (2) of liquefied gas, for example liquefied natural gas, cold, comprising a cryogenic refrigerator (3), a subcooling circuit (4, 5) comprising a set of pipe(s), the subcooling circuit (4, 5) comprising a suction end (4) intended to be housed in a lower portion of a storage (2) of liquefied gas configured to suck in liquefied gas, a heat exchanger (6) ensuring a heat exchange between the sucked subcooling circuit (4, 5) and the refrigerator (3), the subcooling circuit (4, 5) comprising at least one injection end (5, 7) configured to inject into the storage (2) the fluid cooled in the heat exchanger (6),the device (1) further comprising a vaporization gas recovery pipe (8) having an upstream end intended to be connected to an upper portion of the storage (2) for recovering vaporization gas, the recovery pipe (8) comprising a downstream end (18) intended to be connected to a consumer of the vaporization gas, for example a burner and / or an engine, the device (1) comprising a bypass pipe (9) and a set of valve(s) (10) configured to allow the transfer of vaporization gas from the recovery pipe (8) to the sub-cooling circuit (4, 5), the bypass pipe (9) having a first end connected to the recovery pipe (8) and a second end connected to the sub-cooling circuit (4, 5), characterized in that the second end of the bypass pipe (9) is connected to the sub-cooling circuit (4, 5) upstream of the heat exchanger (6).,

2. Device according to claim 1, characterized in that the valve assembly (10) comprises a flow control valve on the bypass pipe (9).

3. Device according to claim 2, characterized in that the flow control valve (10) is a piloted valve configured to transfer a flow of vaporization gas to the subcooling circuit (4, 5) to increase the temperature of the fluid entering the heat exchanger (6) by a determined value, for example between 5 and 25°C.

4. Device according to claim 2 or 3, characterized in that the valve (10) flow control is a pilot-operated valve configured to transfer a flow of vaporization gas to the subcooling circuit (4, 5) to maintain the temperature of the fluid entering the heat exchanger (6) below the saturation temperature of the liquefied gas.

5. Device according to any one of claims 2 to 4, characterized in that the flow control valve (10) is a pilot-operated valve configured to transfer a flow of vaporization gas to the sub-cooling circuit (4, 5) to maintain the temperature of the fluid leaving the heat exchanger (6) above a determined value, for example above -160°C and / or at a value equal to the temperature of the liquefied gas in the storage and / or at a value equal to the temperature of the liquefied gas sucked into the suction end (4).

6. Device according to any one of claims 1 to 5, characterized in that the recovery pipe (8) comprises at least one compressor (11) and in that the first end of the bypass pipe (9) is connected to the recovery pipe (8) downstream of the compressor (11).

7. Device according to claim 6, characterized in that the recovery pipe (8) comprises several compressors (11) in series and in that the first end of the bypass pipe (9) is connected to the recovery pipe (8) downstream of an intermediate compressor (11), i.e. upstream of the last compressor in series.

8. Device according to claim 6 or 7, characterized in that the compressor (11) is configured to supply a gas flow to the bypass pipe (9) having a pressure greater than the pressure of the liquid sucked at the suction end (4) and delivered to the subcooling circuit (4, 5).

9. Device according to any one of claims 1 to 8, characterized in that it comprises a member (12) for mixing the vaporization gas in the sub-cooling circuit (4, 5), the mixing member (12) being located for example at the junction between the second end of the bypass pipe (9) and the sub-cooling circuit (4, 5), the mixing member (12) comprising at least one of: an indirect heat exchanger with injection, a gas injector in liquid, a static mixer, an upstream injector, a filtration system, a condenser pot with bulk or structured packing.

10. Device according to any one of claims 1 to 9, characterized in that the bypass pipe (9) comprises a pre-cooling member (13) in heat exchange with the vaporization gas transferred to the sub-cooling circuit (4, 5), the pre-cooling member (13) being configured for example to cool the flow of vaporization gas transferred to an intermediate temperature between the temperature of the vaporization gas from the recovery pipe (8) and the temperature of the liquefied gas.

11. Device according to any one of claims 1 to 10, characterized in that the recovery pipe (8) comprises a heat exchanger (16) allowing a heat exchange between the vaporization gas from the recovery pipe (8) and the vaporization gas from the bypass pipe (9).

12. Device according to claim 11, characterized in that the bypass pipe (9) comprises a divert pipe (14) and set of valve(s) (15) making it possible to control the flow of vaporization gas from the bypass pipe (9) allowed to circulate in the heat exchanger (16) of the recovery pipe (8).

13. Device according to any one of claims 1 to 12, characterized in that the suction end (4) comprises a suction pump (17).

14. Installation for storing liquefied gas, for example liquefied natural gas, for example a ship for transporting liquefied gas, comprising at least one storage (2) of liquefied gas and a device for keeping the fluid contained in the storage cold, the device (1) for keeping the fluid cold being in accordance with any one of the preceding claims.

15. A method of keeping a storage (2) of liquefied gas cold using a device according to any one of claims 1 to 13 comprising pumping liquefied gas into a cryogenic storage, cooling the pumped liquefied gas and re-injecting the cooled liquefied gas into the storage, the method comprising recovering vaporization gas from the storage and a step of injecting and mixing vaporization gas into the pumped liquefied gas before it is cooled.

16. Method according to claim 15, characterized in that the injection and mixing step is configured to raise the temperature of the pumped liquefied gas before cooling by a determined value and / or to maintain the temperature of the cooled liquefied gas below of a determined threshold and / or at the level of the temperature of the liquefied gas in storage or pumped.

Images