Assembly, vehicle, and method for storing liquefied cryogenic fluids

Abstract

The present invention relates to assemblies, vessels, and methods for storing liquefied cryogenic fluids. [Solution] The assembly comprises a cryogenic tank 2, a line 3 for taking fluid out of the tank, which includes a heat exchanger 9 for heating the taken-out fluid, and a device for cooling the cryogenic fluid in the tank 2, which comprises a cyclic cryogenic refrigerator 10, the refrigerator 10 comprising a cyclic circuit 4 comprising a cyclic fluid, a cyclic fluid compression section comprising at least one compressor 5, cyclic fluid cooling sections 9, 111, 6 comprising at least one heat exchanger, a cyclic fluid expansion section 7 comprising at least one turbine and / or valve, and cyclic fluid heating sections 8, 6 comprising at least one heat exchanger, the cyclic fluid cooling section includes heat exchange between the cyclic circuit 4 and the heating heat exchanger 9 of the take-out line 3.

Description

Technical Field

[0001]

[0001] The present invention relates to an assembly for storing cryogenic fluid, a vehicle comprising such an assembly, and a method.

[0002]

[0002] More specifically, the present invention relates to an assembly for storing a liquefied cryogenic fluid, for example hydrogen, the assembly comprising: a cryogenic tank configured to store the cryogenic fluid; and a line for withdrawing fluid from the tank, the line comprising an upstream end connected to the tank and a downstream end designed to be connected to a user, for example an engine that uses the fluid, wherein the fluid withdrawal line comprises a heat exchanger for heating the withdrawn fluid, the storage assembly comprises a device for cooling the cryogenic fluid in the tank, the device comprising a refrigerant cycle cryocooler provided with a cooling heat exchanger configured to provide cooling capacity to the fluid in the tank, the cryocooler comprises a cycle circuit containing a cycle fluid and is configured to subject the cycle fluid to a thermodynamic cycle to generate cold power, and the cycle circuit comprises: a cycle fluid compression section comprising at least one compressor; a cycle fluid cooling section comprising at least one heat exchanger; a cycle fluid expansion section comprising at least one turbine and / or a valve; and a cycle fluid heating section comprising at least one heat exchanger. Background Art

[0003]

[0003] It is known to cool or subcool cryogenic liquids (for example, such as LNG or LH2 fuel) in tanks that can be transported particularly on ships. It is also known to liquefy boil-off gas in such tanks. This cooling is generally performed by a cycle refrigerator in which the drive member that controls the compressor is generally electric. Electric power can be generated by combustion of flammable gas (heated, and optionally vaporized) that can be drawn from the tank. Therefore, the efficiency of such an assembly can be defined, at least in part, by the consumption of this flammable gas.

[0004]

[0004] An object of the present invention is to improve the effectiveness or efficiency of such assemblies.

[0005]

[0005] For this purpose, the assembly according to the present invention otherwise follows the general definitions given in the above prerequisites, but is essentially characterized in that the cycle fluid cooling unit includes heat exchange between the cycle circuit and a heat exchanger for heating the take-out line.

[0006]

[0006] Furthermore, embodiments of the present invention include: - The bypass line passage in the heat exchanger for heating the extraction line is countercurrent to the flow of the fluid extracted from the tank. - The cycle circuit comprises multiple bypass lines forming multiple passages within the heat exchanger for heating the extraction line, with the first end of each different bypass line connected downstream of a separate compressor. - The heat exchanger for heating the extracted fluid is provided with a heat exchanger in the cyclic fluid cooling section of the cycle circuit, or is composed of a heat exchanger in the said cyclic fluid cooling section. - The heat exchanger for heating the extracted fluid is a heat exchanger in the cycle fluid cooling section, located downstream of the compression section of the cycle circuit and upstream of at least one turbine and / or one valve in the expansion section. - The heat exchanger for heating the extracted fluid is the heat exchanger for the cycle fluid heating section of the cycle circuit, and is located downstream of the cooling heat exchanger. In other words, the heat exchanger for heating the extracted fluid is a heat exchanger common to both the cycle fluid cooling section and the cycle fluid heating section, and simultaneously performs heat exchange between the first flow of relatively high-temperature cycle gas, the second flow of relatively low-temperature cycle fluid, and the extracted gas flow. - The fluid extraction line includes an expansion member for expanding the fluid flow, for example, a turbine configured to expand the fluid flow extracted from the tank and thereby generate a cooling output supplied to a heating heat exchanger. - The expansion member of the extraction line is an electrical component of the assembly, for example, a turbine connected to a generator configured to generate power supplied to an electric motor that drives the compressor of the compression section, and / or a turbine mechanically coupled to the rotary compressor of the compression section. - The fluid extraction line comprises a fluid suction member, for example, a pump located at the bottom of the storage volume of the tank, and / or a compressor connected to the top of the storage volume of the tank. - The fluid extraction line includes at least one compressor and / or at least one additional heat exchanger downstream of the heating heat exchanger. - A device for cooling cryogenic fluid in a tank may have one or more of the following features: a sampling line having a portion that exchanges heat with a cooling heat exchanger of a refrigerator between an upstream end connected to the tank and a downstream end; and the sampling line is configured to draw fluid from the tank, cool it, and inject it into the tank.

[0007]

[0007] The present invention also relates to a vehicle for transporting liquefied cryogenic fluid, such as a ship, comprising an assembly for storing the liquefied cryogenic fluid as described above or in any one of the following features.

[0008]

[0008] The present invention also relates to a method for storing liquefied cryogenic fluid using such an assembly or such transport vehicle, the method comprising the steps of cooling the cryogenic fluid from a tank via a refrigerator, wherein the cyclic fluid of the refrigerator is cooled during the step; taking the cryogenic fluid out of the tank toward a use section; and heating the taken-out cryogenic fluid, wherein the cooling of at least a portion of the cyclic fluid of the refrigerator and the heating of at least a portion of the taken-out cryogenic fluid are carried out jointly by heat exchange between the taken-out cryogenic fluid and the cyclic fluid.

[0009]

[0009] According to other possible specific features, - Cooling of the chiller's cycle fluid, carried out in conjunction with heating of the extracted cryogenic fluid, is cooling of the cycle fluid at the outlet of at least one compression stage. - The cryogenic fluid is a fuel, such as natural gas mainly containing hydrogen (H2) or methane (CH4), and the part used includes an engine for burning the fluid.

[0010]

[0010] Further specific features and advantages will become apparent by reading the following description provided with reference to the figures. [Brief explanation of the drawing]

[0011] [Figure 1] This is a schematic partial diagram illustrating a first example of the structure and operation of the present invention. [Figure 2] This is a schematic partial diagram illustrating a second example of the structure and operation of the present invention. [Figure 3] This is a schematic partial diagram illustrating a third example of the structure and operation of the present invention. [Modes for carrying out the invention]

[0012]

[0011] Throughout the figures, the same reference numerals relate to the same elements. In embodiments for carrying out this invention, the following embodiments are examples. Although the description refers to one or more embodiments, this does not mean that the features apply to only one embodiment. Individual features of different embodiments may also be combined and / or replaced to provide other embodiments.

[0013]

[0012] Figure 1 schematically illustrates an assembly for storing liquefied cryogenic fluids, such as liquefied hydrogen (LH2) or liquefied natural gas (LNG). As schematically shown, this assembly is not fixed in place and can be transported on a vehicle, such as a ship 19.

[0014]

[0013] The assembly 1 comprises at least one cryogenic tank 2 configured to store cryogenic fluid, for example, an insulated cryogenic tank under vacuum or based on other technical solutions typically used for loaded LNG applications. The assembly comprises at least one line 3 for taking fluid from the tank, the line 3 comprising an upstream end connected to the storage volume of the tank 2 and a downstream end intended to be connected to a usage section, for example, a propulsion engine of a vehicle that uses the fluid as fuel. In a possible illustrated example, the take-out line 3 comprises two upstream ends connected to the lower and upper portions of the storage volume, respectively, for taking out liquid and gas. The upstream end housed in the lower part of the tank 2 comprises, for example, a submersible pump 13 for sucking out liquid. The end opening to the upper part of the tank 2 may comprise a member 14 for compressing gas from the gas headspace, the member 14 (e.g., a cryogenic compressor) located, for example, outside the tank 2.

[0015]

[0014] Line 3 passes through a heat exchanger 9 (e.g., a vaporizer) for heating the extracted fluid. Downstream, the extraction line 3 may include one or more compressors 15 to supply the gas to the use section at an appropriate temperature and pressure, and one or more heat exchangers 16 for heating or cooling as needed.

[0016]

[0015] Assembly 1 (or equipment) also includes a device for cooling the cryogenic fluid in tank 2. This cooling device includes a refrigerant cycle cryogenic refrigerator 10 equipped with a cooling heat exchanger 8 configured to provide a cooling force to the fluid in tank 2 (for cooling or subcooling the fluid or for liquefying a portion of its gas phase).

[0017]

[0016] In the illustrated example, the cryogenic fluid in the tank 2 is cooled via a sampling line 17 having a portion that exchanges heat with a cooling heat exchanger 8 of the refrigerator 10 between an upstream end connected to the tank 2 and a downstream end. For example, the sampling line 17 may be configured to draw fluid (liquid and / or gas) from the tank 2, cool it outside the tank 2, and return it to the tank 2 (for example, at the top via injection and / or sprinkler rails and / or at the bottom of the tank 2, in a cooled or liquefied state).

[0018]

[0017] As shown in the figure, at least a portion of the sampling line 17 may be shared with a portion of the extraction line (in particular, one or more ends connected to the storage volume section by the pump member 13 and / or compression member 14).

[0019]

[0018] Naturally, the present invention is not limited to this example. Therefore, cooling and / or liquefaction of the fluid in the tank 2 can be carried out within the tank 2. In this case, at least a portion of the cooling exchanger 8 may be located inside the tank 2.

[0020]

[0019] The refrigerator 10 includes a cycle circuit 4 comprising a cycle fluid (for example, including at least one of neon, argon, helium, nitrogen, oxygen, and hydrogen (H2)), the cycle circuit 4 being configured to provide the cycle fluid to a thermodynamic cycle to generate a cooling output, particularly in a cooling heat exchanger 8, at at least one of the low-temperature ends of the cycle circuit 4.

[0021]

[0020] The cycle circuit 4 includes: a cycle fluid compression unit including at least one compressor 5 (for example, a plurality of compressors in series and / or parallel); a cycle fluid cooling unit including at least one heat exchanger; a cycle fluid expansion unit 7 including at least one turbine and / or one valve (for example, a plurality of turbines and / or valves in series and / or parallel); and cycle fluid heating units 8, 6 including at least one heat exchanger. The cooling unit and the heating unit may in particular include at least one common exchanger that cools a cycle gas flow by heat exchange (for example, in counterflow) with another lower-temperature cycle gas flow, whereby the heating of this another lower-temperature cycle gas flow is simultaneously performed. The cooling unit may also include at least one cooling heat exchanger 111 located at the outlet of at least one compressor and configured to cool the cycle fluid flow heated by compression. Downstream of the expansion unit, the cooling heat exchanger 8 also heats the cycle fluid during heat exchange with an application (fluid) to be cooled.

[0022]

[0021] According to one particular advantageous feature, the cycle fluid cooling unit (particularly the cooling unit at the outlet of one compressor or multiple compressors) includes heat exchange between the cycle circuit 4 and the heating heat exchanger 9 of the extraction line 3. This means that at least part of the cooling of the cycle fluid (for example, after compression) can be performed by a relatively lower-temperature fluid flow extracted from the tank 2.

[0023]

[0022] For this purpose, the cycle circuit 4 may include at least one bypass line 11 that provides a passage through the heating heat exchanger 9 of the extraction line 3, for example, downstream of the compressor 5. In the illustrated example, a plurality of (two) bypass lines 11 are provided downstream of each of the (two) compressors 5 or compression stages. This means that at least part of the cooling performed between compression stages can be provided by the heating heat exchanger 9 (instead of using a heat transfer fluid such as water or air as in the conventional art).

[0024]

[0023] Each bypass line 11 may have an end downstream of the compressor 5 that is connected to a passage through the heating heat exchanger 9 of the take-off line 3, and a downstream end that is connected to the cycle circuit 4 downstream of the first end. In a modified or combined form, only a portion of this cycle fluid is drawn by the bypass line 11 for exchange with the heating heat exchanger 9. This heated flow can then be remixed with the remainder of the cycle fluid flow (not shown) before entering the next compressor.

[0025]

[0024] As shown in the figure, the passage through the heat exchanger 9 may be countercurrent to the flow of the extracted fluid circulating in the extraction line 3. The cycle circuit 4 includes, for example, an isolation valve 12 on the bypass line 11, which allows control of the flow of the cycle gas in the bypass line 11 (for example, to regulate its flow rate in order to circulate the cycle gas to the heat exchanger 9 or not).

[0026]

[0025] Therefore, for example, at the outlet of the compression stage (or more), a portion of the fluid frigory taken out of tank 2 is used in the refrigeration cycle to cool the cycle fluid to, for example, ambient temperature. The relatively high temperature of the cycle is reduced, thereby improving the compression effect and the efficiency of the refrigerator compared to a non-adiabatic Carnot cycle. Energy consumption (in particular, power consumption in the case of an electric motor-driven compressor for the same amount of cold extraction required) can be reduced by about 8-12% compared to known solutions.

[0027]

[0026] At least some of the cooling exchangers 111 that are normally provided at the compression outlet may be omitted. The example in [Figure 2] differs from the example described above only in that the fluid extraction line 3 includes an expansion member 18 for expanding the fluid flow, for example, an expansion turbine configured to expand the fluid flow extracted from the tank 2, thereby generating a cooling output supplied to the heating heat exchanger 9. For example, the fluid flow extracted from the tank 2 is pumped at a pressure of 5 bara to 80 bara and is expanded in the turbine 18 before or during circulation in the cooling exchanger 9, recovering the cooling delivered to the cooling exchanger 9 downstream of the expansion. As shown in the figure, the flow expanded in this turbine 18 can pass through the heating heat exchanger 9 at a lower temperature than the point of entry (suction) into the turbine 18 before returning to the extraction line 3. This means that the flow expanded by the turbine 18 returns to the heating heat exchanger 9 upstream of the branch of line 3 toward the intake of the turbine 18.

[0028]

[0027] Furthermore, the expansion turbine 18 can extract work during expansion. This mechanical work can be used to power the compressor 5 or the compression phase of the refrigeration cycle 10.

[0029]

[0028] The turbine 18 may be connected to a generator, such as an electric motor that drives a compressor(s), configured to generate power to supply one or more electrical components of the assembly. This further improves the efficiency of the equipment. The turbine 18 may be designed to generate the power required (fully or partially) for the reliquefaction function and may use the same turbomachinery technology as that used in the refrigerator 10.

[0030]

[0029] Furthermore, the expansion turbine 18 may be mechanically coupled to the compressor 5 or the compression stage of the refrigeration cycle, for example, as in a single-shaft turbo compressor.

[0031]

[0030] In a modified or combined form, a Rankine-type cycle can be provided to recover the output of the relatively high-temperature flow at the cycle fluid compression outlet and the output of the relatively low-temperature flow of the fluid flow taken out of tank 2. This also improves the effectiveness of the Carnot cycle of the assembly.

[0032]

[0031] The example in [Figure 3] differs from the example in [Figure 1] in that the heat exchanger 9 for heating the extracted fluid is composed of the heat exchanger of the cycle fluid cooling section of the cycle circuit 4. This means that there is no heat exchanger dedicated to heating the extracted fluid, and rather this function is ensured by the heat exchanger of the cycle circuit 4 of the chiller 10 (through at least one passage of the extracted fluid flow in the heat exchanger 9 of the chiller's cycle circuit 4). In contrast, known solutions conventionally have a vaporizer exchanger function on board that integrates a heat source such as a cooling water circuit, which carries the risk of the cooling water circuit freezing in the event of any failure of this heat exchanger.

[0033]

[0032] As shown in the figure, the heat exchanger 9 for heating the extracted fluid may be a heat exchanger in the cycle fluid cooling section located downstream of the compression section of the cycle circuit 4 and upstream of at least one turbine and / or one valve of the expansion section 7. This heat exchanger 9 for heating the extracted fluid may be an exchanger that ensures both heating and cooling of the cycle fluid simultaneously. As shown in the figure, this heat exchanger 9 can simultaneously exchange heat (for example, in a counterflow) between a first flow of relatively hot cycle gas coming out of the compression section and before the expansion section 7 and a second flow of relatively cold cycle fluid coming out of the cooling exchanger 8 before returning to the compression section, for example. This heat exchanger 9 is provided with an additional passage for heating the extracted fluid flow.

[0034]

[0033] As shown in Figure 3, the sampling line 17 may be separate from the extraction line 3, and in particular may have a separate upstream end with a separate pump member 130, which is separate from the pump member of the extraction line 3. In particular, the pump member 130 of the sampling line may be a submersible pump located at the bottom, which has a relatively large flow rate and generates a relatively lower pressurization of the pumped fluid than the pump 13 of the extraction circuit 3.

[0035]

[0034] Furthermore, as shown in [Figure 3], the sampling line 17 may include a bypass 170 at its downstream end and a set of valves 171, the set of valves 171 which allows the pumped and cooled fluid to be returned (for example, through one or more nozzles) to the cooling exchanger 8 in the upper (gas portion) and / or lower (liquid phase) of the tank.

[0036]

[0035] Furthermore, as schematically shown by the dashed lines, a connection 173 (preferably equipped with or associated with a valve) may be provided between these lines (for example, upstream of the cooling exchanger 8) to allow fluid movement between the extraction line 3 and the sampling line 17.

Claims

1. An assembly for storing liquefied cryogenic fluid, such as hydrogen (H2), comprising: a cryogenic tank (2) configured to store the cryogenic fluid; and a fluid extraction line (3) for extracting the fluid from the cryogenic tank, the fluid extraction line (3) comprising a heating heat exchanger (9) for heating the extracted fluid; and the storage assembly comprising a refrigerant cycle cryogenic refrigerator (10) provided with a cooling heat exchanger (8) configured to provide cooling force to the fluid in the cryogenic tank (2), thereby cooling the cryogenic fluid in the cryogenic tank (2). An assembly comprising a device for cooling, wherein the refrigerant cycle cryogenic refrigerator (10) comprises a cycle circuit containing a cycle fluid and configured to supply the cycle fluid to a thermodynamic cycle to generate a cooling output, the cycle circuit (4) comprising a cycle fluid compression section comprising at least one compressor (5), a cycle fluid cooling section (9, 111, 6) comprising at least one heat exchanger, a cycle fluid expansion section (7) comprising at least one turbine and / or valve, and a cycle fluid heating section (8, 6) comprising at least one heat exchanger, wherein the cycle fluid cooling section includes heat exchange between the cycle circuit (4) and the heating heat exchanger (9) of the fluid extraction line (3).

2. The assembly according to claim 1, wherein the cycle circuit (4) comprises a bypass line (11) having a first end connected downstream of the compressor (5), a passage through the heating heat exchanger (9) of the fluid extraction line (3), and a second end connected downstream of the first end to the cycle circuit (4), and the cycle circuit (4) comprises a set of valves (12) configured to control the flow of cycle gas in the bypass line (11).

3. The assembly according to claim 2, characterized in that the passage of the bypass line (11) in the heating heat exchanger (9) of the fluid extraction line (3) is countercurrent to the flow of fluid extracted from the cryogenic tank (2).

4. The assembly according to claim 2 or 3, characterized in that the cycle circuit (4) comprises a plurality of bypass lines (11) that form a plurality of passages within the heating heat exchanger (9) of the fluid extraction line (3), and the first ends of the plurality of bypass lines (11) are each connected downstream of a separate compressor (5).

5. The assembly according to any one of claims 1 to 4, characterized in that the heating heat exchanger (9) for heating the extracted fluid comprises a heat exchanger of the cycle fluid cooling section of the cycle circuit (4), or is composed of the heat exchanger of the cycle fluid cooling section itself.

6. The assembly according to claim 5, characterized in that the heating heat exchanger (9) for heating the extracted fluid is a heat exchanger of the cycle fluid cooling section disposed downstream of the cycle fluid compression section of the cycle circuit (4) and upstream of at least one turbine and / or one valve of the cycle fluid expansion section (7).

7. The assembly according to claim 6, characterized in that the heating heat exchanger (9) for heating the extracted fluid is a heat exchanger in the cycle fluid heating section of the cycle circuit (4) and is disposed downstream of the cooling heat exchanger (8), that is, the heating heat exchanger (9) for heating the extracted fluid is a heat exchanger common to the cycle fluid cooling section and the cycle fluid heating section, and performs heat exchange simultaneously between a first flow of relatively high-temperature cycle gas, a second flow of relatively low-temperature cycle fluid, and the extracted gas flow.

8. The assembly according to any one of claims 1 to 7, characterized in that the fluid extraction line (3) comprises an expansion member (18) for expanding the fluid flow, for example, a turbine configured to expand the fluid flow extracted from the cryogenic tank (2) and thereby generate cold output supplied to the heating heat exchanger (9).

9. The assembly according to claim 8, characterized in that the expansion member (18) of the fluid extraction line is a turbine (18) connected to a generator configured to generate power supplied to the electrical components of the assembly, for example, an electric motor that drives the compressor of the cyclic fluid compression section, and / or a turbine (18) mechanically coupled to the rotary compressor (5) of the cyclic fluid compression section.

10. The assembly according to any one of claims 1 to 9, characterized in that the fluid extraction line (3) comprises a fluid suction member, for example, a pump (13) disposed at the lower part of the storage volume section of the cryogenic tank (2), and / or a compressor (14) connected to the upper part of the storage volume section of the cryogenic tank (2).

11. The assembly according to any one of claims 1 to 10, characterized in that the fluid extraction line (3) comprises at least one compressor (15) and / or at least one additional heat exchanger (16) downstream of the heating heat exchanger (9).

12. The assembly according to any one of claims 1 to 11, characterized in that the apparatus for cooling the cryogenic fluid in the cryogenic tank (2) comprises a sampling line (17) having a portion that exchanges heat with the cooling heat exchanger (8) of the refrigerant cycle cryogenic refrigerator (10) between an upstream end connected to the cryogenic tank (2) and a downstream end, and the sampling line (17) is configured to draw fluid from the cryogenic tank, cool it, and inject it into the cryogenic tank (2).

13. A transport vehicle, such as a ship, for transporting a liquefied cryogenic fluid, comprising an assembly for storing the liquefied cryogenic fluid according to any one of claims 1 to 12.

14. A method for storing a liquefied cryogenic fluid using an assembly according to any one of claims 1 to 12 or a transport vehicle according to claim 13, comprising the steps of: cooling the cryogenic fluid from a cryogenic tank (2) via a refrigerant cycle cryogenic refrigerator (10), wherein the cycle fluid of the refrigerant cycle cryogenic refrigerator is cooled during the step; taking the cryogenic fluid out of the cryogenic tank (2) toward a use section (3); and heating the taken-out cryogenic fluid (9), wherein the cooling of at least a portion of the cycle fluid of the refrigerant cycle cryogenic refrigerator and the heating of at least a portion of the taken-out cryogenic fluid (9) are carried out jointly by heat exchange between the taken-out cryogenic fluid and the cycle fluid.

15. The method according to claim 14, characterized in that the cooling of the cycle fluid of the refrigerant cycle cryogenic refrigerator, carried out in conjunction with the heating (9) of the extracted cryogenic fluid, is the cooling of the cycle fluid at the outlet of at least one compression stage.

16. The method according to claim 14 or 15, characterized in that the cryogenic fluid is a fuel, for example, natural gas mainly containing hydrogen (H2) or methane (CH4), and the usage unit includes an engine for burning the fluid.

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