Cryogenic fluid storage facility and method for filling same

Abstract

The invention relates to a cryogenic fluid storage facility comprising a tank comprising at least a casing, a pressure sensor, a control unit, a filling circuit comprising a first and a second filling line, a first valve and a second valve arranged respectively on the first and the second filling line and being controlled by a control member, the control unit being configured to further determine a first degree of opening of the first valve and a second degree of opening of the second valve and to control the control member in order to open the first and second valves according to the determined degrees of opening so as to ensure an automatic distribution of the flow of fluid from the cryogenic fluid source into the first and second filling lines.

Description

Cryogenic fluid storage installation and its filling process

[0001] The present invention relates to a cryogenic fluid storage installation and its filling method.

[0002] Cryogenic fluid storage systems are known from the prior art. Most prior art systems are filled manually. This requires appropriate training for the operator, who must consider various parameters such as the pressure in the filling line, the pressure in the tank, and the maximum permissible pressure in the tank. The filling process is therefore complex to implement.

[0003] Furthermore, the user must interrupt the filling of the system when the tank is full. Filling is then not optimized; for example, the pressure obtained in the system's tank is not always that desired by the user.

[0004] Furthermore, the tank filling valves are often poorly suited to regulating the flow rate of cryogenic fluid. These valves require frequent maintenance and sometimes the use of additional valves to achieve a filling level that approaches the user's desired level.

[0005] Various methods have been considered to automate the security of this data entry operation. Reference can be made, for example, to documents FR2587432A1, FR2896302, or FR2998642A1.

[0006] Document FR3089598A1 further discloses a cryogenic fluid storage tank, in particular a two-phase mixture of liquid and gas, comprising a first shell intended to contain the cryogenic fluid, at least one withdrawal line having an upstream end connected to the first shell and configured to allow withdrawal of fluid contained in the first shell to the outside of the tank, a tank filling circuit, the filling circuit comprising a first filling line having an upstream end intended to be connected to a fluid source and a downstream end connected to the lower portion of the first shell, the filling circuit comprising a second filling line having an upstream end intended to be connected to the fluid source and a downstream end connected to the upper portion of the first shell,the upstream ends of the first and second filling lines being intended to be connected simultaneously to the same fluid source, the filling circuit comprising a set of distribution valve(s) configured to allow distribution of the fluid from the fluid source into the filling lines, the tank comprising a set of sensor(s) measuring the pressure in the first jacket.

[0007] These installations do not sufficiently simplify, secure or make the filling of a cryogenic storage facility more reliable.

[0008] One aim of the present invention is to offer an alternative to prior art installations that make it possible to secure the filling operation, to better control the pressure in the tank to reach the desired filling level while simplifying the filling process.

[0009] The invention thus relates to a cryogenic fluid storage installation comprising at least: a cryogenic fluid storage tank comprising at least one casing defining an internal volume intended to contain the cryogenic fluid at a pressure greater than atmospheric pressure, a pressure sensor configured to measure at least one pressure in the internal volume, a control unit cooperating with the pressure sensor, a filling circuit comprising at least: a first filling line fluidly connecting a source of cryogenic fluid to an upper portion of the casing, a second filling line fluidly connecting the source to a lower portion of the casing, a first valve and a second valve arranged respectively on the first and second filling lines and being controlled by at least one control element piloted by the control unit,characterized in that the control unit is configured to: determine a first degree of opening of the first valve as a function of said pressure measured by the pressure sensor and a predetermined pressure, and determine a second degree of opening of the second valve as a function of said first degree of opening, and / or determine a second degree of opening of the second valve as a function of said pressure measured by the pressure sensor and a predetermined pressure, and determine a first degree of opening of the first valve as a function of said second degree of opening, and the control unit is configured to: control said at least one control element to operate an opening of the first valve according to said first degree of opening,and an opening of the second valve according to said second degree so as to ensure automatic distribution of the fluid flow from said cryogenic fluid source into the first and second filling lines.

[0010] Depending on the case, the invention may include one or more of the following features:

[0011] The control unit is configured to automatically regulate the pressure in the envelope when the envelope is filled with cryogenic fluid from the source.

[0012] The first valve and the second valve are configured to be fluidly connected simultaneously to said fluid source by means of a connecting element, preferably a common inlet or flange.

[0013] The cryogenic fluid storage installation includes a fluid evacuation circuit comprising at least one protective device, configured to move from a closed position to an open position when the pressure measured by said at least one pressure sensor is greater than a predetermined maximum value, so that said evacuation circuit is in relation with the atmosphere to permit the evacuation of a portion of said cryogenic fluid outside the enclosure.

[0014] The control unit is piloted to open said first valve so that said first degree of opening is equal to 100%, and to open said first valve so that said first degree of opening is less than 100% and open said second valve so that the second degree of opening is proportional to said first degree of opening when said measured pressure is between a first pressure threshold and a second pressure threshold.

[0015] The control unit is programmed to: open the second valve, then open or close said first valve alternately when said measured pressure is respectively greater than a fourth pressure threshold or less than a third pressure threshold.

[0016] The control unit comprises a first actuator and a second actuator configured to actuate the first and second valves by means of a removable attachment.

[0017] The control unit includes a receiver, said pressure sensor being configured to transmit said measured pressure to the receiver of the control unit.

[0018] The cryogenic fluid storage installation includes a removable temperature sensor, intended to be fixed on the protective device and configured to measure a temperature of the protective device and to transmit the measured temperature to the receiver of said control unit, said control unit being configured to control said control device to actuate said first actuator and said second actuator according to said measured temperature.

[0019] The invention further relates to a method for filling at least one cryogenic fluid installation of an installation according to the invention, characterized in that it comprises the steps of:

[0020] (i) connection of said first and second filling lines to said fluid source,

[0021] ii) measurement of said pressure within the internal volume of said envelope,

[0022] (iii) determination of said first degree of opening as a function of said measured pressure and said predetermined pressure, and determination of said second degree of opening as a function of said first degree of opening, or, of said second degree of opening as a function of said measured pressure and said predetermined pressure, and determination of said first degree of opening as a function of said second degree of opening, and

[0023] (iv) opening of the first and second valves respectively to the first and second degree of opening by means of the control device,

[0024] v) filling of the internal volume of the envelope.

[0025] The invention further relates to the use of a cryogenic fluid storage installation according to the invention to store a gas selected from N2, O2, CO2, He, Ar or a mixture of these gases.

[0026] The invention will be better understood upon reading the following description and examining the accompanying figures. These figures are given for illustrative purposes only and are in no way intended to limit the invention.

[0027] is a schematic representation of an embodiment of the installation according to the invention;

[0028] The installation shown in Figure 1 is a cryogenic fluid storage installation, specifically for a two-phase mixture of liquid and gas. The installation comprises at least one tank including a first jacket 1 defining an internal volume intended to contain the cryogenic fluid. The cryogenic fluid is intended to be stored in the tank at a pressure higher than atmospheric pressure, typically between 2 bar and 40 bar, preferably between 2 bar and 37 bar. The first jacket 1 includes a lower portion 11 and an upper portion 12. In one embodiment, the tank is preferably a double-jacketed cryogenic tank; the first jacket 1 may then be surrounded by a second jacket, and the tank then includes thermal insulation in the space between the two jackets (in particular, a vacuum space).

[0029] Typically, the first envelope 1 contains a liquid phase in the lower part (cryogenic fluid in liquid form at very low temperature, for example nitrogen at a temperature of -185°C under a pressure of 2 bar, the value of the temperature is a function of the pressure at equilibrium) and a gaseous phase in the upper part ("gaseous sky").

[0030] The installation includes at least one pressure sensor 5. This pressure sensor 5 is configured to measure the pressure in the internal volume defined by the first envelope 1.

[0031] The installation includes at least one control unit 7. This control unit 7 cooperates with the pressure sensor 5, meaning it takes into account the pressure value measured by the pressure sensor 5. The control unit receives the measured pressure, for example, via a wired or wireless connection. The control unit 7 includes a processor, memory, and various input and output interfaces. Through its interfaces, the control unit 7 can issue instructions to control a control element 6, described below.

[0032] Typically, the installation also includes at least one filling circuit 2 for filling the internal volume. A user predetermines a filling pressure within the volume of the first shell 1; that is, the user sets a target filling pressure to be achieved. For example, this predetermined pressure is equal to the tank's operating pressure, or the tank's operating pressure plus 0.5 bar. This predetermined pressure is, for example, stored. The filling circuit 2 includes at least one first filling line 22 having an upstream end intended to be fluidically connected to a source 3 of cryogenic fluid. For example, this upstream end of the first line 22 is fluidly connected to a hose of a container transported by a filling truck. The first filling line 22 includes a first downstream end connected to the upper portion 12 of the first shell 1.The filling circuit 2 includes at least one second filling line 21 having a second upstream end intended to be fluidly connected to said source 3 of said cryogenic fluid and a second downstream end connected to the lower portion 11 of the first shell 1. The first and second upstream ends are intended to be connected simultaneously to the fluid source 3. In one embodiment, the first and second upstream ends are connected simultaneously to the source 3 by means of a connecting element, for example, a common inlet or flange. This makes maintenance operations less complex, as there are fewer elements to inspect.

[0033] The filling circuit 2 includes at least one first valve 24 and a second valve 23. This first and second valve 24, 23 are arranged respectively on the first and second filling lines 22, 21. This first and second valve 24, 23 are configured to allow distribution of the cryogenic fluid from the source 3 respectively into the first and second filling lines 22, 21. This first and second valve 24, 23 are configured to automatically regulate the pressure in the volume of the first jacket 1 to the predetermined pressure during filling, ensuring automatic distribution of the fluid flow from the source 3 into the first and second filling lines 22, 21 according to the predetermined pressure and said pressure measured by at least one sensor 5.

[0034] The installation also includes at least one control element 6 connected to said first valve 24 and said second valve 23. This control element 6 is configured to control the opening and closing of said first and second valves 24 and 23. The control element 6 is controlled by the control unit 7. More specifically, the control unit 7 is configured to determine a first degree of opening of the first valve 24 based on the pressure measured by the pressure sensor 5 and the predetermined pressure. This control unit 7 then determines a second degree of opening of the second valve 23 based on the first degree of opening. The first and second degrees of opening can, for example, be fixed during filling, i.e., they do not change as the system fills. In another embodiment, these first and second degrees of opening can change as the system fills.

[0035] The control unit 7 is also configured to determine a second opening degree for the second valve 23 based on the pressure measured by the pressure sensor 5 and the predetermined pressure. The control unit 7 then determines the first opening degree for the first valve 24 based on this second opening degree. The first and second opening degrees can, for example, be fixed during filling, meaning they do not change as the system fills. In another embodiment, these first and second opening degrees can vary as the system fills.

[0036] Thanks to the configuration of the control unit 7, during filling, the second or first degree of opening is determined respectively once the first or second degree of opening is determined. This allows for better pressure control. This control unit 7 is also configured to control the control element 6 to open the first valve 24 to the first degree of opening, and the second valve 23 to the second degree of opening, so as to ensure automatic distribution of the fluid flow from the cryogenic fluid source 3 into the first and second filling lines 22, 21.

[0037] The first and second degrees of opening are expressed, for example, as a percentage. In the invention, a degree of opening of 100% corresponds to the valve being fully open. A degree of opening of 0% corresponds to the valve being completely closed, meaning that no more fluid from source 3 can pass into the filling line 22, 21.

[0038] The pressure in the first chamber 1 is therefore regulated to the predetermined pressure setpoint of the installation's tank during filling. This regulation, in other words, the pressure adjustment, is achieved by filling the first chamber 1 via only the first filling line 22, or only via the second filling line 21, or via both filling lines 22 and 21 simultaneously.

[0039] The inventors observed improved pressure stability during filling, with better control of pressure variations. Thus, the tank according to the invention makes the filling operation safer and allows for better control of the pressure within the tank to reach the desired fill level. Furthermore, the first or second opening of the first or second valve 24, 23 is determined first, followed by the second or first opening of the second or first valve 24, 23. In this way, fluid flow regulation is achieved step by step according to the invention. The filling process is therefore simplified and more precisely controlled.

[0040] The inventors also observed that by determining the second opening angle of the second valve 23 based on the first opening angle of the first valve 24, there are no excessively abrupt changes in pressure and flow rate during filling. More specifically, the inventors found that by regulating the fluid flow in the second pipe 21 based on the first opening angle of the first valve 24, the tank components, such as valves, pumps, or gas circulation lines, are less damaged. Furthermore, the opening and closing movements of the valves are better controlled. When these openings are performed not by an operator but by a pneumatic or mechanical system, the tightening of valves 24 and 23 is reduced, resulting in less damage. The overall lifespan of the tank is thus extended, and fewer maintenance operations are required.

[0041] In one embodiment, the first and second valves 24, 23 are opened simultaneously. In another embodiment, the valves do not open simultaneously, resulting in a delay. For example, the control unit 7 is configured to wait a few moments before programming the control device 6. This waiting time allows the pressure stability within the internal volume to be verified.

[0042] In one embodiment, the control unit 7 is configured to automatically regulate the pressure in the envelope 1 when it is filled with cryogenic fluid from the source 3. There is then no operator intervention during the regulation.

[0043] In one embodiment, the pressure sensor 5 is arranged outside the casing 1. It is suitable for measuring the pressure of a gaseous phase or a liquid phase.

[0044] In one embodiment, the cryogenic fluid storage system includes a drainage circuit. This drainage circuit allows at least a portion of the cryogenic fluid to be evacuated from the internal volume, for example, if the measured pressure exceeds a predetermined maximum value. This predetermined maximum value is, for example, selected by the user and can be stored. The drainage circuit includes at least one protective device 4 fluidically connected to the internal volume of the enclosure 1. This protective device 4 is, for example, an overflow valve, a safety valve, or a pressure relief valve. This protective device 4 is configured to switch from a closed position to an open position when the pressure measured by said at least one pressure sensor 5 exceeds the predetermined maximum value.This allows for the regulation, when necessary, of the gas phase pressure in the event of non-use of gas by the customer. Indeed, when gas is not drawn for an extended period, a natural pressure increase occurs within the enclosure 1. In one embodiment, the protective device 4 is sensitive to pressure variations and can automatically switch from the closed to the open position when the measured pressure exceeds the predetermined maximum value. In another embodiment, the protective device 4 can be controlled by the control device 6. In this case, the control unit 7 programs the control device 6 to open the protective device 4. When the protective device 4 is open, the venting circuit is connected to the atmosphere.This allows at least some of the cryogenic fluid to be evacuated from the enclosure 1 when the pressure measured by the pressure sensor 5 exceeds a predetermined maximum value. This protective device 4 can be a valve and / or a rupture disc. The predetermined maximum value is typically the maximum permissible pressure of the tank (specified by the manufacturer). Thus, cryogenic fluid can flow out of the enclosure 1, i.e., in a direction that drains the internal volume of the first enclosure 1 to the outside.

[0045] In one embodiment, this evacuation circuit comprises an evacuation pipe having a third upstream end configured to be fluidically connected to the internal volume of the enclosure 1 and a fourth downstream end configured to allow the evacuation of a portion of the cryogenic fluid. The protective device 4 is then arranged respectively on the evacuation pipe.

[0046] The predetermined pressure is typically the tank's operating pressure (for example, based on the gas user's requirements and the downstream installation). This pressure may be the pressure at which the gaseous fluid must be maintained, depending on the application in the gaseous space, or the pressure at which the liquid portion at the bottom of the tank (fluid in its liquid phase) must be maintained. This predetermined pressure is between 2 bar and 37 bar.

[0047] The predetermined maximum value is between 2 bar and 37 bar.

[0048] In one embodiment, the reservoir includes a set of sensor(s) preferably measuring (and displaying and / or transmitting, as appropriate) the pressure in the gaseous phase (upper part) and / or the pressure in the lower part (liquid phase), as well as the liquid level of the liquid phase (lower part of the first jacket). This liquid level can be determined by the pressure difference between the bottom and top of the first jacket, from which the height of the hydrostatic fluid column is deduced.

[0049] The fluid pressure at the lower end of the first envelope is equal to the pressure of the gaseous phase plus the hydrostatic pressure generated by the height of the liquid phase.

[0050] For this purpose, the sensor assembly(ies) may include a pressure tap of the gas phase (measurement in the upper part of the first envelope 1) and a pressure tap of the liquid phase (measurement in the lower part of the first envelope 1).

[0051] Typically, the sensor set(s) may include sensors of the type measuring static pressure and / or differential pressure.

[0052] Valves 23, 24 are examples of valves that are mechanically, pneumatically or electronically controlled.

[0053] In one embodiment, the control element 6 is programmed by the control unit 7 to open the first valve 24 such that the first degree of opening is equal to 100%, or strictly less than 100%. Then, when the pressure is between a first pressure threshold and a second pressure threshold, for example, between 95% and 105% of the predetermined pressure, the first valve 24 is opened so that the first degree of opening is strictly less than 100%, and the second valve 23 is opened so that the second degree of opening is proportional to the first degree of opening. The control unit 7 thus determines a first degree of opening equal to 100%, or strictly less than 100%, for example, at the start of the filling of the casing 1.Then, when the measured pressure is between a first pressure threshold and a second pressure threshold, for example, between 95% and 105% of the predetermined pressure, the control unit 7 will stabilize this pressure. The control unit then determines, for example continuously, a first degree of opening strictly less than 100% based on the measured pressure and the predetermined pressure. The second degree of opening is, as explained, determined proportionally to the first degree of opening. These first and second degrees of opening are determined, for example, continuously, until the end of the filling process. When the measured pressure approaches or falls below the first threshold, the second valve 23 opens slightly further, and the second degree of opening is increased.When the measured pressure approaches or exceeds the second threshold, the second valve 23 is slightly closed, reducing its second degree of opening. This stabilizes the pressure within the enclosure. Determining the degree of opening of the second valve 23 is straightforward thanks to a proportional law. Furthermore, this embodiment allows the use of a set of valves 24, 23 with a common fluid inlet and two outlets to the filling lines 22, 21. The filling flow rate can also be stabilized at a specific value, thus maintaining a constant filling flow rate. The first and second pressure thresholds are user-defined, for example, stored in the memory of the control unit 7. In one embodiment, the first and second pressure thresholds are percentages of the predetermined pressure.The first pressure threshold is, for example, equal to 95% of the predetermined pressure. The second pressure threshold is, for example, equal to 105% of the predetermined pressure. These pressure threshold values ​​allow for a reasonable number of valve openings / closings during filling, i.e., one that does not prematurely damage the valves. The first and second pressure thresholds can be expressed in bar. The first pressure threshold is, for example, equal to the predetermined pressure minus 1 bar. The second pressure threshold is, for example, equal to the predetermined pressure plus 1 bar. Preferably, the first pressure threshold is equal to the predetermined pressure minus 0.4 bar. The second pressure threshold is equal to the predetermined pressure plus 0.4 bar. In one embodiment, the valves are pneumatically controlled.

[0054] The inventors also observed that by determining the second opening angle of the second valve 23 based on the first opening angle of the first valve 24, there are no excessively abrupt changes in pressure and flow rate during filling. More specifically, the inventors found that by regulating the fluid flow in the second pipe 21 based on the first opening angle of the first valve 24, the tank components, such as valves, pumps, or gas circulation lines, are less damaged. Furthermore, the opening and closing movements of the valves are better controlled. When these openings are performed not by an operator but by a pneumatic or mechanical system, the tightening of valves 24 and 23 is reduced, resulting in less damage. The overall lifespan of the tank is thus extended, and fewer maintenance operations are required.

[0055] In one embodiment, the control element 6 is programmed to: open the second valve 23, open or close the first valve 24 alternately when the measured pressure is respectively greater than a fourth pressure threshold or less than a third pressure threshold.

[0056] Thus, the control unit 7 first determines a second degree of opening at the start of the filling of the tank 1, based on the measured pressure and the predetermined pressure. This second degree of opening is, for example, between 0 and 100%. In one embodiment, this second degree of opening is between 0% and a value strictly less than 100%. The control unit also determines the first degree of opening, which is then equal to 0%. Then, the control unit 7 determines the first degree of opening based on the measured pressure and the predetermined pressure. More precisely, when the measured pressure is below a third pressure threshold, the first valve 24 is, for example, closed at the first degree of opening, which is then equal to 0%. That is to say, the degree of opening of the first valve 24 decreases or is then equal to 0%. When the measured pressure is above the fourth pressure threshold, the first valve 24 is opened.The degree of opening of the first valve 24 is then increased.

[0057] In one embodiment, the third and fourth pressure thresholds are percentages of the predetermined pressure. For example, the third pressure threshold is equal to 95% of the predetermined pressure. The fourth pressure threshold is equal to 105% of the predetermined pressure. These pressure threshold values ​​allow for a reasonable number of valve openings / closings during filling, i.e., one that does not prematurely damage the valves. The third and fourth pressure thresholds can be expressed in bar. For example, the third pressure threshold is equal to the predetermined pressure minus 1 bar. The third pressure threshold is equal to the predetermined pressure plus 1 bar. Preferably, the third pressure threshold is equal to the predetermined pressure minus 0.4 bar. The third pressure threshold is equal to the predetermined pressure plus 0.4 bar.These third and fourth pressure thresholds are determined through testing. They are, for example, stored in the memory of the control unit 7. In one embodiment, when the measured pressure exceeds the fourth pressure threshold, the first valve 24 opens between a value strictly greater than 0% and a value strictly less than 100%, for example, 35% or 50%. Indeed, the inventors observed that opening the first valve 24 to 100% causes the measured pressure to drop too rapidly. This phenomenon results in excessive valve opening and closing. These opening values ​​are determined through testing. The control element 6 is thus programmed to fix the second degree of opening of the second valve 23. Then, once the second degree of opening of the second valve 23 is fixed, the control element 6 is programmed to open the first valve 24.This first valve 24 is then alternately opened and closed during the tank filling operation, depending on the measured pressure and the predetermined pressure. Thus, only the degree of opening of the first valve 24 is changed: either the first valve 24 is in an open position, or it is in a closed position. That is to say, the first degree of opening is either less than 100%, preferably less than 50%, preferably even less than 35%, or it is equal to 0%. Therefore, the degree of opening of the second valve 23 is changed less. The second valve 23 is thus subject to less wear, and the installation requires less maintenance. This embodiment is easy to implement on existing equipment without the need for complex modifications. In one embodiment, the second degree of opening of the second valve 23 is changed between 0% and 100%, but at a lower frequency than the first degree of opening.In one embodiment, the measured pressure is the pressure of the gaseous phase of the envelope 1. In one embodiment, the valves are controlled with an electronic control.

[0058] In one embodiment, the control member 6 is programmed to: open said first valve 24, then, close or open said second valve 23 alternately when the measured pressure is respectively greater than a sixth pressure threshold or less than a fifth pressure threshold.

[0059] Thus, the control unit 7 first determines a first degree of opening at the start of the filling of the envelope 1, based on the measured pressure and the predetermined pressure. This first degree of opening is, for example, between 0 and 100%. In one embodiment, this first degree of opening is between 0% and a value strictly less than 100%. The control unit also determines the second degree of opening, which is then equal to 0%. The control unit 7 then determines the second degree of opening based on the measured pressure and the predetermined pressure. More precisely, when the measured pressure is below a fifth pressure threshold, the second valve 23 is opened. The degree of opening of the second valve 23 is then increased. When the pressure is above a sixth pressure threshold, the second valve 23 is closed. The degree of opening of the second valve 23 decreases or is then equal to 0%.

[0060] In one embodiment, the fifth and sixth pressure thresholds are percentages of the predetermined pressure. For example, the fifth pressure threshold is equal to 95% of the predetermined pressure. The sixth pressure threshold is equal to 105% of the predetermined pressure. These pressure threshold values ​​allow for a reasonable number of valve openings / closings during filling, i.e., one that does not prematurely damage the valves. The fifth and sixth pressure thresholds can be expressed in bar. For example, the fifth pressure threshold is equal to the predetermined pressure minus 1 bar. The sixth pressure threshold is equal to the predetermined pressure plus 1 bar. Preferably, the fifth pressure threshold is equal to the predetermined pressure minus 0.4 bar. The sixth pressure threshold is equal to the predetermined pressure plus 0.4 bar. These fifth and sixth pressure thresholds are determined through testing.For example, they are stored in the memory of the control unit 7. In one embodiment, when the measured pressure is below the fifth pressure threshold, the second valve 23 is then opened between a value strictly greater than 0% and a value strictly less than 100%, for example, 35% or 50%. Indeed, the inventors observed that opening the second valve to a value below 35% results in significant flow variations in the pump, a phenomenon that tends to cause premature wear of the valves. These opening values ​​are determined through testing. The control element 6 is thus programmed to fix the first degree of opening of the first valve 24. Then, once the first degree of opening of the first valve 24 is fixed, the control element 6 is programmed to command the opening of the second valve 23.This second valve 23 is then alternately opened and closed during the tank filling operation, depending on the measured pressure and the predetermined pressure. Thus, only the degree of opening of the second valve 23 is changed during filling: the second valve 23 is either in an open position or in a closed position. That is to say, the second degree of opening is either less than 100%, preferably less than 50%, preferably even less than 35%, or it is equal to 0%. Therefore, the degree of opening of the first valve 24 is less affected. Consequently, the first valve 24 experiences less wear and tear, and the installation requires less maintenance. This embodiment is easy to implement on existing equipment without the need for complex modifications.In one embodiment, the first degree of opening of the first valve 24 is modified between 0% and 100%, but at a lower frequency than the second degree of opening. In one embodiment, the measured pressure is the pressure of the liquid phase of the casing 1.

[0061] In one embodiment, the control element 6 comprises a first actuator and a second actuator. The first and second actuators are configured to be assembled to the first and second valves 24, 23, respectively, by means of a removable fastener. These actuators therefore comprise a fastener and a motor. Once the actuator is attached to the valve, the motor opens or closes the valve. This motor can be a stepper motor. Furthermore, for example, the first and second actuators can cooperate with the first and second valves 24, 23, respectively, to form a removable male / female connection / locking system. Other types of actuators can be considered, such as actuators consisting of jaws that are attached to the valve handwheel, for example. The choice of actuators depends on the valves 24, 23 present in the installation.The proposed control and monitoring solution can therefore be portable (it could be installed on a truck, for example) and thus require no mechanical modifications to existing cryogenic storage facilities. This allows the control and monitoring solution to be implemented on the existing fleet of tanks. The solution is therefore simple to implement.

[0062] In one embodiment, the control unit 7 includes a receiver. Then the pressure sensor 5 is configured to transmit the measured pressure value to the receiver of the control unit.

[0063] In one embodiment, the installation includes a removable temperature sensor intended to be attached to the protective device 4. In another embodiment, this removable temperature sensor is attached upstream of the protective device 4. The removable temperature sensor is then configured to measure the temperature of the protective device 4, or upstream of the protective device 4, and to transmit the measured temperature to the control unit. The control unit 7 is configured to program the control element 6 to actuate first and second actuators based on the temperature measured by the temperature sensor. Thus, the temperature sensor detects the presence of liquid near the protective device 4. If this is the case, the temperature of the protective device 4 will drop by several degrees, typically by 10 degrees, or reach the fluid's equilibrium temperature at 1 bar.This equilibrium temperature is, for example, -195°C for nitrogen. In one embodiment, the temperature sensor is a portable temperature sensor equipped with a thermocouple and a means of wireless connection (for example, a Bluetooth connection) to the cryogenic fluid source 3. For example, this component is attached to the protective element 4 before the filling operation. In one embodiment, the temperature sensor triggers an audible or visual alarm when the measured temperature drops by several degrees or reaches the fluid's equilibrium temperature at 1 bar. This equilibrium temperature is, for example, -195°C for nitrogen.

[0064] In one embodiment, the control element 6 is programmed to move the first and second valves 24, 23 into intermediate opening positions in which the first and second degrees of opening are strictly greater than 0% and strictly less than 100%.

[0065] The invention also relates to a method for filling at least one cryogenic fluid storage installation according to the invention. The method comprises the following steps:

[0066] (i) connection of said first and second filling lines 22, 21 to said fluid source 3,

[0067] ii) measurement of said pressure in the internal volume of the envelope 1,

[0068] iii) determination

[0069] said first degree as a function of said measured pressure and said predetermined pressure, and determination of said second degree of opening as a function of said first degree of opening, or

[0070] said second degree as a function of said measured pressure and said predetermined pressure, and determination of said first degree of opening as a function of said second degree of opening,

[0071] And

[0072] (iv) opening of said first valve 24 and said second valve 23 respectively to said first degree of opening and said second degree of opening by means of said control member 6,

[0073] v) filling of the internal volume of the envelope.

[0074] In one embodiment, the method of the invention further comprises, after step i), a step of positioning a temperature sensor upstream of said protective device 4 and measuring the temperature, and after step iv), a step of closing said valves 24, 23 when said temperature is below a predefined threshold temperature. The threshold temperature is, for example, a temperature defined by the user and stored in the control unit 7.

[0075] In one embodiment, steps ii) to v) of the process are performed continuously. This is particularly the case when valves 24, 23 are opened / closed by means of an electronic system. In another embodiment, steps ii) to iv) of the process are performed every 5 minutes, preferably every minute, or even more preferably at a frequency predetermined by the user. This is particularly the case when valves 24, 23 are opened / closed by means of an electronic system. This predetermined frequency is, for example, recorded by means of a human-machine interface.

[0076] The invention also relates to a method of using a cryogenic fluid storage installation according to the invention. This installation allows the storage of a gas selected from N2, O2, CO2, He, Ar, or a mixture of these gases.

Claims

A cryogenic fluid storage installation comprising at least: a cryogenic fluid storage tank comprising at least one casing (1) defining an internal volume intended to contain the cryogenic fluid at a pressure greater than atmospheric pressure, a pressure sensor (5) configured to measure at least one pressure in said internal volume, a control unit (7) cooperating with the pressure sensor (5), a filling circuit (2) comprising at least: a first filling line (22) fluidly connecting a source (3) of cryogenic fluid to an upper portion (12) of the casing (1), a second filling line (21) fluidly connecting said source (3) to a lower portion (12) of the casing (1), a first valve (24) and a second valve (23) arranged respectively on the first and second filling lines (22,21) and being controlled by at least one control element (6) operated by said control unit (7), characterized in that said control unit (7) is configured to: determine a first degree of opening of the first valve (24) as a function of said pressure measured by the pressure sensor (5) and a predetermined pressure, and determine a second degree of opening of the second valve (23) as a function of said first degree of opening, and / or determine a second degree of opening of the second valve (23) as a function of said pressure measured by the pressure sensor (5) and a predetermined pressure, and determine a first degree of opening of the first valve (24) as a function of said second degree of opening, and the control unit (7) is configured to: operate said at least one control element (6) to operate an opening of the first valve (24) according to said first degree of opening,and an opening of the second valve (23) according to said second degree so as to ensure an automatic distribution of the fluid flow from said source (3) of cryogenic fluid into the first and second filling lines (22, 21), said control member (6) is piloted to: - open the second valve (23), then, - open or close said first valve (24) alternately when said measured pressure is respectively greater than a pressure threshold, said fourth pressure threshold, or less than another pressure threshold, said third pressure threshold. Installation according to claim 1, characterized in that the control unit is configured to automatically regulate, during filling of the envelope (1) with cryogenic fluid from the source (3), the pressure in said envelope (1). An installation according to any one of the preceding claims, characterized in that the first valve (24) and the second valve (23) are configured to be fluidically connected simultaneously to said fluid source (3) by means of a connecting element, preferably a common inlet or flange. An installation according to any one of the preceding claims, characterized in that it comprises a fluid evacuation circuit comprising at least: a protective device (4), configured to move from a closed position to an open position when the pressure measured by said at least one pressure sensor (5) is greater than a predetermined maximum value, so that said evacuation circuit is in relation with the atmosphere to allow the evacuation of a portion of said cryogenic fluid outside the enclosure (1). Cryogenic installation according to any one of the preceding claims, characterized in that said control member comprises a first actuator and a second actuator configured to actuate the first and second valves (24, 23) by means of a removable attachment. Installation according to any one of the preceding claims, characterized in that said control unit (7) comprises a receiver, said pressure sensor (5) being configured to transmit said measured pressure to said receiver of said control unit (7). An installation according to any one of claims 7 to 8, characterized in that it comprises a removable temperature sensor, intended to be fixed on said protective element (4) and configured to measure a temperature of said protective element (4) and to transmit said measured temperature to said receiver of said control unit (7), said control unit (7) being configured to control said control element (6) to actuate said first actuator and said second actuator as a function of said measured temperature. A method for filling at least one cryogenic fluid installation according to claims 1 to 7, characterized in that it comprises the steps of: i) connecting said first and second filling lines (22, 21) to said fluid source (3), ii) measuring said pressure in the internal volume of said casing (1), iii) determining said first degree of opening as a function of said measured pressure and said predetermined pressure, and determining said second degree of opening as a function of said first degree of opening, or, of said second degree of opening as a function of said measured pressure and said predetermined pressure, and determining said first degree of opening as a function of said second degree of opening, iv) opening said first and second valves (24, 23) respectively to said first and second degree of opening by means of said control member (6), v) filling the internal volume of said casing (1). Use of a cryogenic fluid storage facility according to any one of claims 1 to 7 for storing a gas selected from N2, O2, CO2, He, Ar or a mixture of these gases.

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