Method for controlling a cryogenic fluid production installation

Abstract

A method for controlling a cryogenic fluid production plant (1), for example, liquefied hydrogen, the plant (1) being configured to operate in a first nominal mode in which the cycle time has a first determined nominal cycle time and in which the adsorption phase has a determined nominal adsorption time, the plant (1) further being configured to operate in a second mode in which the cycle time has a second cycle time shorter than the first determined nominal cycle time, the method comprising the step of measuring at least one principal impurity level in the source of gas to be cooled. Abstract figure: Fig. 1

Description

Title of the invention: Method for controlling a cryogenic fluid production installation

[0001] The present invention relates to a method for controlling a cryogenic fluid production installation and a cryogenic fluid production installation.

[0002] A hydrogen liquefier is generally configured to produce Liquid hydrogen is produced from a gas source (feed gas). When this feed gas is produced by an electrolyzer, it may contain impurities whose quantity and nature can vary significantly. This is particularly problematic during the electrolyzer's start-up.

[0003] There is therefore a need for a control method for a cryogenic fluid production installation, capable of operating in a nominal mode in which the feed gas contains few impurities and in a degraded mode in which the feed gas contains a greater quantity of impurities.

[0004] The present invention aims to effectively overcome these drawbacks by providing a method for controlling a cryogenic fluid production installation, for example, liquefied hydrogen, the installation comprising a gas circuit to be cooled having an upstream end intended to be connected to a gas source and a downstream end for delivering the cryogenic fluid, for example, a liquefied gas, the installation comprising a cryogenic purification device disposed in the gas circuit to be cooled, the cryogenic purification device comprising at least two adsorbers, each adsorber following the same adsorption cycle with a cycle time, the adsorption cycle comprising at least one adsorption phase and one regeneration phase,the installation being configured to operate in a first nominal mode in which the cycle time has a first determined duration of nominal cycle time and in which the adsorption phase has a determined nominal adsorption duration, the installation being further configured to operate in a second mode in which the cycle time has a second duration of cycle time less than the first determined duration of nominal cycle time, the process comprising the steps of: , - measure at least one principal impurity level in the gas source to be cooled, the principal impurity being at least one of: N2, Ar and O2, each principal impurity being respectively associated with a first specific threshold value and a second specific threshold value, greater than the first specific threshold value; - configure installation 1 to operate in the first mode, when each measured main impurity level is below its first specific threshold value; - configure installation 1 to operate in the second mode, when at least one of each main impurity rate measured is greater than its first specific threshold value.

[0005] Such a process makes it possible to maintain continuous operation of such an installation even when a peak of impurities appears in the gas source.

[0006] According to one embodiment, the second cycle time duration is between 20% and 70% of the first determined nominal cycle time duration, for example between 40% and 60%.

[0007] According to one embodiment, the first specific threshold value is equal to 50 ppm for N2, 0.1 ppm for Ar and 0.1 ppm for 1'O2.

[0008] According to one embodiment, the second specific threshold value is equal to 200 ppm for N2, 1 ppm for Ar and 1 ppm for 1'O2.

[0009] According to one embodiment, the process comprises the steps of: - measure at least one secondary impurity level in the gas source to be cooled, the secondary impurity being notably distinct from the primary impurity, each secondary impurity being respectively associated with a third specific threshold value; - configure installation 1 to operate in the second mode, when at least one of each measured secondary impurity rate is greater than its third specific threshold value.

[0010] According to one embodiment, the secondary impurity is at least one of: CO, CH4, CO2.

[0011] According to one embodiment, the third specific threshold value is equal to 50 ppm for CO, 100 ppm for CH4 and 50 ppm for CO2.

[0012] According to one embodiment, the installation being in the first mode, when at least one of each measured principal impurity rate is greater than its first specific threshold value and at least one of the adsorbers in the adsorption phase has been in the adsorption phase for a period greater than or equal to 50% of the determined nominal adsorption time, the process includes the step of configuring the installation so that at least one of the adsorbers in the adsorption phase switches into the regeneration phase and so that at least one of the adsorbers that is not in the adsorption phase switches into the adsorption phase.

[0013] According to one embodiment, the installation being in the first mode, when at least one measured secondary impurity level is greater than its third specific threshold value and at least one of the adsorbers in the adsorption phase is in the adsorption phase for a period greater than or equal to 50% of the determined nominal adsorption time, the process includes the step of configuring the installation so that at least one of the adsorbers in the adsorption phase switches into the regeneration phase and so that at least one of the adsorbers that is not in the adsorption phase switches into the adsorption phase.

[0014] According to one embodiment, when at least one of each main impurity level measured is greater than its second specific threshold value, the process includes the step of configuring the installation so that at least one of the adsorbers in the adsorption phase switches into the regeneration phase and so that at least one of the adsorbers which is not in the adsorption phase and which has completed its regeneration phase switches into the adsorption phase.

[0015] According to one embodiment, the process includes a step of scanning with N2, of at least one of the adsorbers in the regeneration phase.

[0016] According to one embodiment, the cryogenic purification device is a temperature-modulated adsorption treatment unit, the adsorption cycle being of the TSA type.

[0017] The invention further relates to an installation for the production of a cryogenic fluid, for example liquefied hydrogen, comprising a circuit of gas to be cooled having an upstream end intended to be connected to a gas source and a downstream end for delivering the cryogenic fluid, for example a liquefied gas, the installation comprising a cryogenic purification device disposed in the circuit of gas to be cooled, the installation comprising a control unit for the implementation of the process as described above.

[0018] According to one embodiment, the installation comprises: - a set of heat exchangers in heat exchange with the gas circuit to be cooled; - a pre-cooling device in heat exchange with at least a first part of the heat exchanger assembly and configured to pre-cool the gas circuit to be cooled to a first determined temperature, the pre-cooling device comprising a refrigerator with a refrigeration cycle of a pre-cooling fluid in a pre-cooling circuit, the pre-cooling circuit comprising a pre-cooling fluid compression element; - a cryogenic cooling device in heat exchange with at least one second part of the heat exchanger assembly and configured to cool the gas circuit to be cooled to a second determined temperature lower than the first temperature, the cryogenic cooling device comprising a cycle refrigerator refrigeration of a cycle gas in a cycle circuit, the cycle circuit comprising a cycle gas compression device; the cryogenic purification device being positioned upstream of the second part of the exchanger assembly.

[0019] According to one embodiment, the cryogenic purification device is arranged between the first part of the heat exchanger assembly and the second part of the heat exchanger assembly, in particular by being configured to be supplied with a gas having a temperature between 20 °C and -250 °C, for example between -100 °C and -250 °C.

[0020] According to one embodiment, the first part of the set of exchangers is arranged in a first cold box.

[0021] According to one embodiment, the pre-cooling circuit includes a device for cooling the compressed pre-cooling fluid, a device for expanding the compressed and cooled pre-cooling fluid and a device for heating the expanded pre-cooling fluid.

[0022] According to one embodiment, the cycle circuit includes a cooling element for the compressed cycle gas, an expansion element for the compressed and cooled cycle gas and a heating element for the expanded cycle gas.

[0023] According to one embodiment, the installation includes a storage to allow the storage of the cryogenic fluid, the downstream end being connected to the storage for the storage of the cryogenic fluid.

[0024] The invention may also relate to any alternative device or method comprising any combination of the above or below features.

[0025] The invention will be better understood upon reading the following description and examining the accompanying figure. This figure is given only by way of illustration and in no way limits the invention.

[0026] [Fig-1] Fig. 1 is a schematic representation of an installation according to the invention; and

[0027] [Fig.2] The [Fig.2] is a schematic representation of a method according to the invention.

[0028] With reference to [Fig. 1], a fluid production installation 1 is shown. cryogenic, for example of liquefied hydrogen, comprising a circuit 2 of gas to be cooled having an upstream end 21 intended to be connected to a source of gas such as hydrogen, and a downstream end 22 for delivering the cryogenic fluid, for example a liquefied gas such as liquefied hydrogen.

[0029] Installation 1 includes a cryogenic purification device 3 disposed in the circuit 2 of gas to be cooled.

[0030] The cryogenic purification device 3 comprises at least two adsorbers, each adsorber following the same adsorption cycle with a cycle time, the adsorption cycle comprising at least one adsorption phase and one regeneration phase.

[0031] In the example shown, the cryogenic purification device 3 is a temperature-modulated adsorption treatment unit, the adsorption cycle being of the TSA type.

[0032] Installation 1 includes a set of heat exchangers 5, 6 in thermal exchange with the circuit 2 of gas to be cooled.

[0033] The installation 1 includes a pre-cooling device 8 in heat exchange with at least a first part 5 of the heat exchanger assembly 5, 6 and configured to pre-cool the circuit 2 of gas to be cooled to a first determined temperature.

[0034] The pre-cooling device 8 includes a refrigerator with a pre-cooling fluid refrigeration cycle in a pre-cooling circuit 18.

[0035] The pre-cooling circuit 18 includes a pre-cooling fluid compression element 28.

[0036] The pre-cooling circuit 18 includes a device for cooling the compressed pre-cooling fluid, a device for expanding the compressed and cooled pre-cooling fluid 38 and a device for heating the expanded pre-cooling fluid.

[0037] The installation 1 includes a cryogenic cooling device 9 in heat exchange with at least a second part 6 of the heat exchanger assembly 5, 6 and configured to cool the circuit 2 of gas to be cooled to a second determined temperature lower than the first temperature.

[0038] The cryogenic cooling device 9 comprises a refrigeration cycle refrigerator of a cycle gas in a cycle circuit 19.

[0039] The cycle circuit 19 includes a cycle gas compression element 29.

[0040] The cycle circuit 19 includes a cycle gas cooling element compressed, a 39 expansion device for the compressed and cooled cycle gas and a heating device for the expanded cycle gas.

[0041] The cryogenic purification device 3 is arranged upstream of the second part 6 of the exchanger assembly 5, 6.

[0042] The cryogenic purification device 3 is disposed between the first part 5 of the heat exchanger assembly 5, 6 and the second part 6 of the heat exchanger assembly 5, 6, in particular by being configured to be supplied with a gas having a temperature between 20 °C and -250 °C, for example between -100 °C and -250 °C.

[0043] The first part 5 of the exchanger assembly 5, 6 is arranged in a first cold box and the second part 6 of the exchanger assembly 5, 6 is arranged in a second cold box.

[0044] The installation 1 includes a storage 10 to allow the storage of the cryogenic fluid, the downstream end 22 being connected to the storage 10 for the storage of the cryogenic fluid.

[0045] Installation 1 is configured to operate in a first nominal mode in which the cycle time has a first determined duration of nominal cycle time and in which the adsorption phase has a determined nominal adsorption duration.

[0046] Installation 1 is further configured to operate in a second mode in which the cycle time has a second cycle time duration less than the first determined nominal cycle time duration.

[0047] In one embodiment, the determined nominal adsorption time is approximately equal to one week and when the installation is in the second mode, the adsorption time is approximately equal to one day.

[0048] As shown in [Fig.2], the installation 1 includes a control unit for the implementation of a control process, the process comprising the steps of: - measuring El at least one principal impurity level in the gas source to be cooled, the principal impurity being at least one of: N2, Ar and O2, each principal impurity being respectively associated with a first specific threshold value and a second specific threshold value, greater than the first specific threshold value; - configure E2 installation 1 to operate in the first mode, when each measured principal impurity rate is below its first specific threshold value; - configure E3 installation 1 to operate in the second mode, when at least one of each main impurity rate measured is above its first specific threshold value.

[0049] In one embodiment, the first specific threshold value is equal to 50 ppm for N2, 0.1 ppm for Ar and 100 ppb for 1'O2.

[0050] The process comprises the steps of: - measure at least one secondary impurity level in the gas source to be cooled, the secondary impurity being notably distinct from the primary impurity, each secondary impurity being respectively associated with a third specific threshold value; - configure installation 1 to operate in the second mode, when at least one of each measured secondary impurity rate is greater than its third specific threshold value.

[0051] With the installation 1 in the first mode, when at least one of each measured principal impurity rate is greater than its first specific threshold value and at least one of the adsorbers in the adsorption phase has been in the adsorption phase for a period greater than or equal to 50% of the determined nominal adsorption time, the process includes the step of configuring the installation 1 so that at least one of the adsorbers in the adsorption phase switches into the regeneration phase and so that at least one of the adsorbers that is not in the adsorption phase switches into the adsorption phase.

[0052] When at least one of each main impurity level measured is greater than its second specific threshold value, the process includes the step of configuring the installation 1 so that at least one of the adsorbers in the adsorption phase switches into the regeneration phase and so that at least one of the adsorbers which is not in the adsorption phase and which has completed its regeneration phase switches into the adsorption phase.

[0053] The process includes a step of scanning with N2, of at least one of the adsorbers in the regeneration phase.

Claims

Demands

1. A method for controlling an installation (1) for the production of a cryogenic fluid, for example, liquefied hydrogen, the installation (1) comprising a circuit (2) of gas to be cooled having an upstream end (21) intended to be connected to a gas source and a downstream end (22) for delivering the cryogenic fluid, for example, a liquefied gas, the installation (1) comprising a cryogenic purification device (3) disposed in the circuit (2) of gas to be cooled, the cryogenic purification device (3) comprising at least two adsorbers, each adsorber following the same adsorption cycle with a cycle time, the adsorption cycle comprising at least one adsorption phase and one regeneration phase, the installation (1) being configured to operate in a first nominal mode in which the cycle time has a first determined duration of nominal cycle time and in which the adsorption phase has a determined nominal adsorption duration,the installation (1) being further configured to operate in a second mode in which the cycle time has a second cycle time duration shorter than the first determined nominal cycle time duration, the process comprising the steps of: - measuring at least one principal impurity level in the gas source to be cooled, the principal impurity being at least one of: N2, Ar and O2, each principal impurity being respectively associated with a first specific threshold value and a second specific threshold value, greater than the first specific threshold value; - configuring the installation (1) to operate in the first mode, when each measured principal impurity level is less than its first specific threshold value; - configuring the installation (1) to operate in the second mode, when at least one of each measured principal impurity level is greater than its first specific threshold value.

2. A method according to the preceding claim, comprising the steps: - measure at least one secondary impurity rate in the gas source to be cooled, the secondary impurity being notably distinct from the primary impurity, each secondary impurity being respectively associated with a specific third threshold value; - configure the installation (1) to operate in the second mode, when at least one of each measured secondary impurity rate is greater than its specific third threshold value.

3. A method according to any one of the preceding claims, wherein the installation (1) is in the first mode, when at least one of each measured principal impurity rate is greater than its first specific threshold value and at least one of the adsorbers in the adsorption phase has been in the adsorption phase for a period greater than or equal to 50% of the determined nominal adsorption time, the method comprises the step of configuring the installation (1) so that at least one of the adsorbers in the adsorption phase switches into the regeneration phase and so that at least one of the adsorbers that is not in the adsorption phase switches into the adsorption phase.

4. A method according to any one of the preceding claims, where at least one of each measured principal impurity level is greater than its second specific threshold value, the method comprises the step of configuring the installation (1) so that at least one of the adsorbers in the adsorption phase switches into the regeneration phase and so that at least one of the adsorbers which is not in the adsorption phase and which has completed its regeneration phase switches into the adsorption phase.

5. A method according to any one of the preceding claims, the method comprising a step of scanning with N2, of at least one of the adsorbers in the regeneration phase.

6. A method according to any one of the preceding claims, the cryogenic purification device (3) being a temperature-modulated adsorption treatment unit, the adsorption cycle being of the TSA type.

7. Installation (1) for the production of a cryogenic fluid, for example liquefied hydrogen, comprising a circuit (2) of gas to be cooled having an upstream end (21) intended to be connected to a source of gas and a downstream end (22) for delivering the cryogenic fluid, for example a liquefied gas, the installation (1) comprising a cryogenic purification device (3) disposed in the circuit (2) of gas to be cooled, the installation (1) comprising a control unit for implementing the process according to one of the preceding claims.

8. Installation (1) according to claim 7, comprising: - a set of heat exchangers (5, 6) in heat exchange with the circuit (2) of gas to be cooled; - a pre-cooling device (8) in heat exchange with at least a first part (5) of the set of heat exchangers (5, 6) and configured to pre-cool the circuit (2) of gas to be cooled to a first determined temperature, the pre-cooling device (8) comprising a refrigerator with a refrigeration cycle of a pre-cooling fluid in a pre-cooling circuit (18), the pre-cooling circuit (18) comprising a pre-cooling fluid compression element (28);- a cryogenic cooling device (9) in heat exchange with at least a second part (6) of the heat exchanger assembly (5, 6) and configured to cool the circuit (2) of gas to be cooled to a second determined temperature lower than the first temperature, the cryogenic cooling device (9) comprising a cycle refrigerator for refrigerating a cycle gas in a cycle circuit (19), the cycle circuit (19) comprising a cycle gas compression element (29); the cryogenic purification device (3) being disposed upstream of the second part (6) of the heat exchanger assembly (5, 6).

9. Installation (1) according to any one of claims 7 to 8, the cryogenic purification device (3) being disposed between the first part (5) of the heat exchanger assembly (5, 6) and the second part (6) of the heat exchanger assembly (5, 6), in particular being configured to be supplied with a gas having a temperature between 20 °C and -250 °C, for example between -100 °C and -250 °C.

10. Installation (1) according to any one of claims 7 to 9, comprising a storage (10) for enabling the storage of the cryogenic fluid, the downstream end (22) being connected to the storage (10) for the storage of the cryogenic fluid.

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