Cryogenic fluid storage and treatment facility

Abstract

Title of the invention: Installation for storing and treating cryogenic fluid The present invention relates to an installation for storing and treating cryogenic fluid (1) comprising at least one storage tank (2), a consumption and / or treatment system (22), a loading and / or unloading line (14) for the cryogenic fluid in liquid form (L), a supply line (20) for the consumption and / or treatment system (22) with a fuel prepared from a gas resulting from the evaporation of the cryogenic fluid (G), the supply line (20) comprising at least one compressor (24), the installation (1) comprising a pipe (26) connected to the supply line (20) between the compressor (24) and the consumption and / or treatment system (22), the pipe (26) being connected to a bottom of the tank (6), the pipe (26) carrying a control member (36) for the circulation of gas (G) within of the conduct (26).Abstract figure: Figure 1.

Description

Title of the invention: Cryogenic fluid storage and treatment installation

[0001] The present invention relates to the field of cryogenic fluids, and more particularly the storage and treatment of such cryogenic fluids.

[0002] Gaseous hydrocarbons at room temperature and atmospheric pressure such as natural gas, petroleum gas are liquefied at cryogenic temperatures, i.e. temperatures below -25°C, in order to facilitate their transport and / or storage. The hydrocarbons thus liquefied, also called cryogenic fluids in liquid form or cryogenic liquids, are then placed in tanks of a structure.

[0003] Such tanks are nevertheless never perfectly thermally insulated, so that evaporation of the cryogenic liquid occurs. The phenomenon of natural evaporation is called boil-off in English and the gas resulting from this evaporation is called boil-off gas in English, its acronym being BOG. ​​The tanks of the structure thus include both the cryogenic liquid in a lower portion of the tank, and the gas resulting from the evaporation of this cryogenic liquid in an upper portion of the tank.

[0004] Within the tank, the temperature of the cryogenic liquid is not uniform, and a hot upper layer forms upon contact with the gas resulting from the evaporation of the cryogenic liquid. Such a hot upper layer induces the formation of steam within the tank on the one hand and increases the pressure within this tank on the other hand.

[0005] The present invention falls within this context by proposing an efficient and economical means of mixing the cryogenic liquid present within the tank, so as to reduce the pressure within the tank.

[0006] The main subject of the present invention is thus a cryogenic fluid storage and treatment installation comprising at least one cryogenic fluid storage tank comprising a tank bottom and a tank top, a consumption and / or treatment system, a line for loading and / or unloading the cryogenic fluid in liquid form configured to connect at least the tank bottom to a storage terminal, a line for supplying the consumption and / or treatment system with a fuel prepared from a gas resulting from the evaporation of the cryogenic fluid contained in liquid form in the storage tank, the supply line connecting at least the tank top to the consumption and / or treatment system and comprising at least one compressor arranged between the storage tank and the consumption and / or treatment system, the cryogenic fluid storage and treatment installation comprising a pipe connected to a first end on the supply line between the compressor and the consumption and / or treatment system, the pipe being connected by a second end to the bottom of the tank, the pipe carrying a device for controlling the circulation of gas within the pipe.

[0007] The storage and treatment installation according to the invention is for example integrated within a structure. It is configured for the circulation of a cryogenic fluid in liquid form on the one hand, and for the circulation of a gas resulting from the evaporation of this cryogenic fluid in liquid form on the other hand, both the cryogenic fluid in liquid form and the gas being stored within one or more storage tanks of the storage and treatment installation. The cryogenic liquid is more particularly stored in a bottom of the tank, the gas resulting from the evaporation of the cryogenic liquid being on the contrary stored in a top of the tank. Here, the terms "bottom of the tank" and "top of the tank" are understood to mean areas of the storage tank, the bottom of the tank corresponding to a lower portion of this tank while the tank top corresponds to its upper portion.

[0008] The tank may be an atmospheric pressure storage tank or a storage tank with a maximum pressure of 6 bars.

[0009] In order to fill the tank or empty it, the storage and treatment installation comprises a loading and / or unloading line within which the cryogenic fluid circulates in its liquid form. According to the embodiments, the loading and / or unloading line connects the storage tank to a storage terminal, for example a storage terminal located on a land coast, to a production unit or even to a consumption network. Here, the term "loading or unloading" means that this line is used either for loading cryogenic fluid from the storage terminal or the production unit to the storage tank, or for unloading cryogenic fluid from the storage tank to the storage terminal or the consumption network, or for both loading and unloading at different times. The storage terminal is at least configured for storing cryogenic fluid in liquid form.

[0010] A consumption and / or treatment system of the storage and treatment facility is configured to be supplied from the tank. According to the embodiments, the consumption and / or treatment system may take the form of an engine for producing electricity, mechanical force, or heat; a gas export network; or a reliquefaction unit. This consumption and / or treatment system is for example supplied with a fuel in gaseous form, which here corresponds to the gas resulting from the evaporation of the cryogenic fluid in liquid form. For this purpose, the storage and treatment facility comprises a supply line connecting the storage tank to the consumption and / or treatment system. treatment. This supply line is configured to be crossed by the gas resulting from the evaporation of the cryogenic fluid in liquid form, that is to say by the cryogenic fluid in its gaseous form. In order to provide the consumption and / or treatment system with fuel at an adequate pressure, the supply line is equipped with a compressor, which makes it possible to adjust the pressure of the gas resulting from the evaporation of the cryogenic fluid in liquid form before its delivery to the consumption and / or treatment system.

[0011] The fuel is chosen from chemical species such as hydrogen, natural gas, ethane, ethylene, petroleum gas, ammonia and their mixtures.

[0012] The feed line opens at one of its ends into the tank ceiling, while the loading and / or unloading line opens at one of its ends into the tank bottom.

[0013] In order to prevent the formation of a hot upper layer within the cryogenic fluid in liquid form in a portion of this cryogenic fluid in liquid form which is in contact with or close to the gas, i.e. in contact with or close to the tank ceiling, the storage and treatment installation is configured to implement a bubbling phenomenon. Such a bubbling phenomenon consists of creating eddies within the tank in order to mix the cryogenic fluid in liquid form and in particular the hot upper layer with the rest of the cryogenic fluid in liquid form.

[0014] The bubbling phenomenon is here obtained by injecting the gas resulting from the evaporation of the cryogenic fluid after it has passed through the compressor. To do this, the storage and treatment installation comprises a pipe, a first end of which is arranged on the supply line between the compressor and the consumption and / or treatment system. This pipe therefore constitutes a diversion of at least a portion of the gas resulting from the evaporation of the cryogenic fluid in liquid form which would otherwise be delivered to the consumption and / or treatment system. At its second end, the pipe is connected to the tank bottom to inject the gas into the cryogenic fluid in liquid form, with a view to optimal mixing of this cryogenic fluid in liquid form. The pipe is, depending on the embodiments, connected to the tank bottom directly or indirectly.

[0015] The pipe also carries a member for controlling the circulation of the gas resulting from the evaporation of the cryogenic fluid in liquid form within the pipe. This control member is a control valve. The control member has a closed state in which it prevents the circulation of the gas and an open state in which it allows its circulation. In the open state of the control member, the gas resulting from the evaporation of the cryogenic fluid in liquid form is returned to the bottom of the tank and therefore participates in the bubbling phenomenon.

[0016] According to an exemplary embodiment, the presence of the pipe makes it possible to supply the consumption and / or treatment system and to carry out the bubbling phenomenon independently or simultaneously.

[0017] According to an optional characteristic of the invention, the second end of the pipe is connected to the loading and / or unloading line.

[0018] This is a first embodiment of the invention, in which the pipe joins the loading and / or unloading line which itself opens into the bottom of the tank. The pipe is therefore here indirectly connected to the bottom of the tank via the loading and / or unloading line.

[0019] In this first embodiment, the gas resulting from the evaporation of the cryogenic fluid in liquid form uses the loading and / or unloading line within which the cryogenic fluid in liquid form otherwise circulates. This makes it possible to limit costs and space requirements by reusing a line already present within the architecture of the storage and treatment installation. The use of the loading and / or unloading line is possible outside of operations for loading or unloading the cryogenic fluid in liquid form within the tank, the loading and / or unloading line then emptying by gravity or by flushing the gas into the storage tank and therefore being usable for circulating the gas resulting from the evaporation of the cryogenic fluid in liquid form therein.

[0020] According to an optional characteristic of the invention, the second end of the pipe opens into the bottom of the tank.

[0021] According to an optional characteristic of the invention, the second end of the pipe opens into the bottom of the tank in the form of a bubbling ramp.

[0022] This corresponds to a second embodiment, in which the pipe directly joins the bottom of the tank. The gas resulting from the evaporation of the cryogenic fluid in liquid form then circulates in a pipe dedicated to it. This makes it possible to achieve the bubbling phenomenon even during loading and / or unloading of the cryogenic fluid in liquid form.

[0023] According to an optional characteristic of the invention, the pipe is configured to be crossed by the gas resulting from the evaporation of the cryogenic fluid.

[0024] According to an optional characteristic of the invention, the cryogenic fluid storage and treatment installation comprises a first device for measuring the pressure within the tank and / or the temperature of the cryogenic fluid in liquid form within the tank.

[0025] The pressure and / or temperature measuring device makes it possible to measure either the pressure in the entire tank, for example by taking a measurement in the tank ceiling, or the temperature of the cryogenic fluid in liquid form in the bottom of the tank, or both the pressure and the temperature.

[0026] According to an optional characteristic of the invention, the cryogenic fluid storage and treatment installation comprises a second device for measuring the pressure of the gas resulting from the evaporation of the cryogenic fluid at the outlet of the compressor.

[0027] The device for measuring the pressure of the gas resulting from the evaporation of the cryogenic fluid in liquid form is a second measuring device. It is configured to measure the pressure on the compressor outlet line.

[0028] According to an optional characteristic of the invention, the cryogenic fluid storage and treatment installation comprises a control system configured to open or close the control member as a function of a value recorded by the first and / or the second measuring device.

[0029] The control system is a centralized device. It is configured to open or close the control member either as a function of a value recorded by the first pressure and / or temperature measuring device, or as a function of a value recorded by the second pressure measuring device of the gas resulting from the evaporation of the cryogenic fluid, or preferably as a function of these two values.

[0030] The invention further relates to a structure intended for the transport and / or storage of cryogenic fluid, comprising a cryogenic fluid storage and treatment installation as mentioned above.

[0031] The structure is in particular a floating structure or a land-based structure. For example, the structure may, depending on the embodiments, be a vessel using liquefied natural gas as fuel (or LFS for liquefied natural gasfueled vessel), a floating gas production, storage and unloading unit (or FLNG for floating liquid natural gas), a floating storage and regasification unit (or FRSU for floating storage regaseification unit), a gravity platform (or GBS for gravity-based structure), or even a land-based reservoir or a port storage structure.

[0032] The invention further relates to a method of using a cryogenic fluid storage and treatment installation according to any one of the preceding claims, during which the control member of the pipe is open to send gas resulting from the evaporation of the cryogenic fluid at the bottom of the tank and is closed to prevent the return of gas resulting from the evaporation of the cryogenic fluid at the bottom of the tank.

[0033] The method of using the storage and treatment installation corresponds to the implementation of bubbling when this is necessary to mix the cryogenic fluid in liquid form within the tank, by switching the control member to its open state when such bubbling is useful and on the contrary by switching the control member to its closed state when bubbling is not necessary.

[0034] According to an optional characteristic of the invention, the opening and closing of the control body are governed by the control system.

[0035] In other words, the transition of the control member from its closed state to its open state and vice versa is controlled by the control system.

[0036] According to an optional characteristic of the invention, the method of use comprises a first step during which the control system calculates a theoretical pressure within the tank from a temperature measured by the first pressure and / or temperature measuring device, a second step during which the control system calculates a difference between the theoretical pressure and an actual pressure measured within the tank by the first pressure and / or temperature measuring device, and a third step during which the control system compares the difference to a threshold value.

[0037] The first step, the second step and the third step correspond to the verification of a first parameter necessary for controlling the control member. This first parameter depends at least on the pressure within the storage tank. This pressure can be directly measured or calculated from a temperature of the cryogenic fluid in liquid form in the storage tank.

[0038] According to an optional characteristic of the invention, the method of use comprises a first step during which the control system calculates a theoretical temperature of the cryogenic fluid in liquid form within the tank from a pressure measured by the first pressure and / or temperature measuring device, a second step during which the control system calculates a difference between the theoretical temperature and an actual temperature measured within the tank by the first pressure and / or temperature measuring device, and a third step during which the control system compares the difference to a threshold value.

[0039] This is an alternative, in which the first parameter depends on the temperature of the cryogenic fluid in liquid form within the tank.

[0040] According to an optional characteristic of the invention, the method of use comprises a comparison phase during which the control system compares a pressure of the gas resulting from the evaporation of the cryogenic fluid measured by the second pressure measuring device at the outlet of the compressor to a range of operating pressure values ​​of the consumption and / or treatment system.

[0041] This comparison phase corresponds to the verification of a second parameter necessary for controlling the control member. The range of operating pressure values ​​of the consumption and / or treatment system depends on the nature of this consumption and / or treatment system. It is for example between 0.5 and 2.5 bars for a burner, between 4 and 8 bars for a motor providing electricity, or between 14 and 18 bars for an engine used for XDF type propulsion.

[0042] According to an optional characteristic of the invention, the control system controls the opening of the control member when the measured pressure is within the range of operating pressure values ​​of the consumption and / or treatment system.

[0043] In other words, if the pressure measured at the compressor outlet is within the range of values ​​corresponding to the nature of the consumption and / or treatment system, the control system orders the control member to switch from its closed state to its open state, or to maintain it in its open state. The gas resulting from the evaporation of the cryogenic fluid in liquid form then circulates in the pipe to the storage tank within which it performs the bubbling operation. The control member is, in its open state, either partially open or completely open depending on requirements. Outside the aforementioned range of values, the control member is in its closed state and bubbling does not take place. The return of the gas resulting from the evaporation of the cryogenic fluid in liquid form to the storage tank is thus only carried out if the consumption and / or treatment system does not need it as fuel.

[0044] According to an optional characteristic of the invention, the control system commands the opening of the control member if the difference compared during the third step between the theoretical pressure and the actual pressure measured within the tank by the first pressure and / or temperature measuring device is greater than the threshold value.

[0045] The return of gas resulting from the evaporation of the cryogenic fluid in liquid form to the storage tank is therefore only implemented if the pressure within the storage tank is too high and therefore requires bubbling to mix the cryogenic fluid in liquid form to reduce the pressure. For example, the control system commands the opening of the control member if there is a difference of at least 20 mbar between the theoretical pressure and the actual measured pressure.

[0046] According to an optional characteristic of the invention, the control system commands the opening of the control member if the difference compared during the third step between the theoretical pressure and the actual pressure measured within the tank by the first pressure and / or temperature measuring device is greater than the threshold value.

[0047] For example, the control system commands the opening of the control member if there is a difference of at least 0.2°C between the theoretical temperature and the actual measured temperature.

[0048] According to an optional characteristic of the invention, the method of use comprises a step in which different measurements of the pressure and / or temperature in the storage tank are carried out by the first pressure and / or temperature measuring device, and a step in which the control system compares a rate of change of the pressure and / or temperature with a reference value.

[0049] In other words, the control system controls the opening of the control member and therefore the implementation of bubbling when, from measurements of the pressure and a derivative of these pressure values, or from measurements of the temperature of a derivative of these temperature values, the control system detects a rapid rise in pressure and / or temperature within the storage tank.

[0050] According to an optional characteristic of the invention, the control system commands the closing of the control member if the difference compared during the third step between the theoretical pressure and the actual pressure measured within the tank by the first pressure and / or temperature measuring device is less than the threshold value.

[0051] According to an optional characteristic of the invention, the control system commands the closing of the control member if the difference compared during the third step between the theoretical temperature and the actual temperature measured within the tank by the first pressure and / or temperature measuring device is less than the threshold value.

[0052] The control system operates according to a simultaneous check; as soon as the pressure and / or the temperature within the storage tank reach values ​​which do not require the implementation of the bubbling process, the control system orders the closing of the control member, even if the check of the second parameter, namely the pressure at the outlet of the compressor, was compatible with the opening of the control member.

[0053] Other characteristics, details and advantages of the invention will emerge more clearly on reading the description which follows on the one hand, and examples of embodiment given for informational and non-limiting purposes with reference to the appended drawings on the other hand, in which:

[0054] [Fig.l] illustrates, schematically, an installation for storing and transporting cryogenic fluid, here represented according to a first embodiment in which a pipe is connected at a first end to a supply line and at a second end to a loading and / or unloading line;

[0055] [Fig.2] illustrates, schematically, a variant of the first embodiment of the storage and transport facility of [Fig.l];

[0056] [Fig.3] illustrates, schematically, a second embodiment of the installation storage and transportation of [Fig.l], in which the pipeline is connected to its first end to the supply line and opens at its second end directly into a cryogenic fluid storage tank.

[0057] The features, variants and the different embodiments of the invention may be combined with each other, in various combinations, provided that they are not incompatible or mutually exclusive. In particular, variants of the invention may be imagined comprising only a selection of features described below in isolation from the other features described, if this selection of features is sufficient to confer a technical advantage and / or to differentiate the invention from the prior art.

[0058] In the figures, the elements common to several figures retain the same reference.

[0059] Figures 1 to 3 thus illustrate, schematically, a storage and treatment installation 1 according to the invention, such a storage and treatment installation 1 being here integrated within a structure such as a floating structure or a land-based structure.

[0060] The storage and treatment facility 1 is configured to operate a circulation of cryogenic fluid. For this purpose, cryogenic fluid in liquid form L is stored in at least one storage tank 2 of the storage and treatment facility 1.

[0061] Since the thermal insulation of the storage tank 2 is not perfect, a portion of the cryogenic fluid in liquid form L evaporates naturally and forms a gas resulting from the evaporation of the cryogenic fluid in liquid form G. The storage tank 2 therefore comprises both the cryogenic fluid in liquid form L and the gas resulting from the evaporation of the cryogenic fluid in liquid form G, a separation between these two fluids being represented in the figures by a dotted horizontal line. The cryogenic fluid is, for example, methane.

[0062] In the figures, the storage and treatment installation 1 here has a single storage tank 2. It is understood that the description which follows in relation to this storage tank 2 may apply, mutatis mutandis, to other storage tanks for embodiments in which the structure would have several storage tanks.

[0063] The storage tank 2 is delimited by a bottom wall 4, which corresponds to its lowest wall. From this bottom wall 4 extends a tank bottom zone 6, which corresponds for example to at least half of a height of the storage tank 2 measured perpendicular to the bottom wall 4. At least the tank bottom 6 is intended for the storage of the cryogenic fluid in liquid form L. Conversely, the gas resulting from the evaporation of the cryogenic fluid in liquid form G is stored in a tank headspace 8, which corresponds to its highest portion. The tank headspace 8 extends from a ceiling wall 10 opposite the back wall 4.

[0064] The storage and treatment facility 1 is connected to a storage terminal 12 located outside the structure, for example on a land coast. The storage terminal 12 is here an example given for illustrative purposes only; it could be envisaged, without departing from the scope of the invention, that the storage and treatment facility 1 is rather connected to a production unit or even to a consumption network. The storage terminal 12 makes it possible to store at least cryogenic fluid in liquid form L. In certain embodiments, the storage terminal 12 makes it possible to store both cryogenic fluid in liquid form L and gas resulting from the evaporation of the cryogenic fluid in liquid form G.

[0065] The storage and treatment installation 1 is more precisely connected to the storage terminal 12 at least via a loading and / or unloading line 14. This loading and / or unloading line 14 allows the circulation of the cryogenic fluid in liquid form L between the storage tank 2 and the storage terminal 2. Thus, during a loading operation of the structure, the cryogenic fluid in liquid form L is conveyed through the loading and / or unloading line 14 from the storage terminal 12 to the storage tank 2, and conversely, during an unloading operation, the cryogenic fluid in liquid form L circulates within this loading and / or unloading line 14 from the storage tank 2 to the storage terminal 12.

[0066] As can be seen in the figures, the loading and / or unloading line 14 here comprises a plurality of pipes 16 which open into the storage tank 2. The loading and / or unloading line 14 more precisely comprises a first pipe 16A, a second pipe 16B and a third pipe 16C which extend at least partially within the storage tank 2. In a case not shown, the line 16C is not present in the installation. These pipes are connections to a main line 13 of the loading and / or unloading line 14. The second pipe 16B is connected to this main line 13 at a first intersection 17A, while the first pipe 16A and the third pipe 16B are both connected to the main line at a second common intersection 17B.More specifically, the first pipeline 16A is connected to the main line of the loading and / or unloading line 14 at the second intersection 17B, the third pipeline 16C itself being connected to the first pipeline 16A between this second intersection 17B and the storage tank 2.

[0067] The first pipe 16A and the second pipe 16B open into the bottom of the tank 6, close to the bottom wall 4. The second pipe 16B is equipped with a pump 18, which in particular facilitates the unloading of the cryogenic fluid in liquid form L. The pump 18 is arranged at one end of the second pipe 16B, for example in an area between the bottom wall 4 and a plane parallel to it and arranged at a distance of three meters from it. On the contrary, the third pipe 16C opens into the tank ceiling 8, in the vicinity of the ceiling wall 10. The presence of pipes 16 opening at different heights in the storage tank 2 has the effect of facilitating the loading of cryogenic fluid in liquid form L, which can thus be carried out by one and / or the other of the first pipe 16A and the third pipe 16C.

[0068] In addition to the loading and / or unloading line 14, the storage and treatment installation 1 comprises a supply line 20. This supply line 20 is configured for the circulation of gas resulting from the evaporation of the cryogenic fluid in liquid form G. The supply line 20 connects the storage tank 2 to a consumption and / or treatment system 22 of the storage and treatment installation 1. This consumption and / or treatment system 22 is for example an engine intended to be supplied with a fuel formed by the gas resulting from the evaporation of the cryogenic fluid in liquid form G. The supply line 20 opens into the storage tank 2; it is more particularly connected to the ceiling wall 10 of the storage tank 2. Between the storage tank 2 and the consumption and / or treatment system 22, the supply line 14 is equipped with a compressor 24.This compressor 24 makes it possible to adjust the pressure of the gas resulting from the evaporation of the cryogenic fluid in liquid form G prior to its delivery to the consumption and / or treatment system 22.

[0069] According to the invention, the storage and treatment installation 1 comprises a pipe 26 configured for the circulation of the gas resulting from the evaporation of the cryogenic fluid in liquid form G. This pipe 26 is connected to the supply line 20. More precisely, the pipe 26 extends between a first end 28 and a second end 30, its first end 28 being connected to the supply line 20 between the compressor 24 and the consumption and / or treatment system 22. It is understood that the pipe 26 constitutes for the gas resulting from the evaporation of the cryogenic fluid in liquid form G a means of avoiding the consumption and / or treatment system 22.

[0070] The gas resulting from the evaporation of the cryogenic fluid in liquid form G circulating within the pipe 26 is intended to be returned to the storage tank 2. For this purpose, the second end 30 of the pipe 26 is connected to the storage tank 2 and more particularly to the bottom of the tank 6. The second end 30 is, depending on the embodiments, connected directly or indirectly to the bottom of the tank 6. Thus, [Fig.l] illustrates a first embodiment, [Fig.2] illustrates a variant of the first embodiment embodiment, and [Fig.3] illustrates a second embodiment.

[0071] In Figures 1 and 2, the second end 30 of the pipe 26 is connected to the loading and / or unloading line 14. In the variant of [Fig. 1], the second end 30 is connected between the storage terminal 12 and the first intersection 17A for the second pipe 16B. In the variant of [Fig. 2], the second end 30 is connected to the first pipe 16A, between the second pipe 16B and the ceiling wall 10 of the storage tank 2. In this second variant, the gas resulting from the evaporation of the cryogenic fluid in liquid form G does not circulate within the main line 13 of the loading and / or unloading line 14; rather, it uses a dedicated conduit 32. This dedicated conduit 32 is a portion of the pipe 26 arranged in parallel with the main line 13.

[0072] In the second embodiment of [Fig. 3], the pipe 26 does not open into the loading and / or unloading line 14. In this second embodiment, in fact, the gas resulting from the evaporation of the cryogenic fluid in liquid form G circulates within the dedicated pipe 32 which here opens into the bottom of the tank 6. The second end 30 of the pipe 26 is, in certain alternatives, equipped with a bubbling ramp or even an ejector.

[0073] Whatever the embodiment, the storage and treatment installation 1 is equipped with a control system 34. This control system 34 is configured to decide whether the gas resulting from the evaporation of the cryogenic fluid in liquid form G must be delivered to the consumption and / or treatment system 22 or returned to the storage tank 2. The control system for this purpose controls a control member 36 arranged on the pipe 26. This control member 36 here takes the form of a valve which has either a closed state in which the passage of gas resulting from the evaporation of the cryogenic fluid in liquid form G within the pipe 26 is prevented, or an open state in which the passage of gas resulting from the evaporation of the cryogenic fluid in liquid form G is authorized.It is understood that in the closed state of the control member 36 all of the gas resulting from the evaporation of the cryogenic fluid in liquid form G is delivered to the consumption and / or treatment system 22, while in its open state, on the contrary, the gas resulting from the evaporation of the cryogenic fluid in liquid form G can partly be delivered to the consumption and / or treatment system and partly circulate in the pipe 26 and return to the storage tank 2. The control system 34 thus controls the transition from the closed state to the open state of the control member 36 or conversely the transition from its open state to its closed state. When the gas resulting from the evaporation of the cryogenic fluid in liquid form G is returned to the storage tank 2, it participates in a bubbling phenomenon which will be described in more detail below in relation to a method of using the storage and treatment installation 1.

[0074] The control system 34 decides whether to open or close the control member 36 based on certain parameters measured or calculated within the storage and treatment facility 1. To do this, the storage and treatment facility 1 comprises various measuring devices. As part of these measuring devices, the storage and treatment facility 1 has a first measuring device 38, or first pressure and / or temperature measuring device 38, configured to record values ​​within the storage tank 2, and a second measuring device 40, or second pressure measuring device 40, configured to record values ​​at the outlet of the compressor 24.

[0075] The first measuring device 38 is configured to measure the pressure within the storage tank 2 and / or the temperature of the cryogenic fluid in liquid form L within the storage tank 2. This first measuring device 38 here comprises both a pressure sensor 38A and a temperature sensor 38B. The second measuring device 40 is configured to measure the pressure of the gas resulting from the evaporation of the cryogenic fluid in liquid form G at its outlet from the compressor 24. This second measuring device 40 here corresponds to a pressure sensor.

[0076] A method of using the storage and treatment installation 1 will now be described. This method of use makes it possible, when required, to implement the bubbling phenomenon mentioned above in order to mix the cryogenic fluid in liquid form L within the storage tank 2 and thus to reduce the pressure within this storage tank 2.

[0077] During the method of use, the opening of the control member 36 is operated by the control system 34 when a given pressure is reached within the storage tank 2 and a given pressure is reached at the outlet of the compressor 24. It is understood that these two pressures correspond to parameters verified by the control system 34 prior to the control member passing into its open state.

[0078] The verification of the pressure within the storage tank 2 corresponds to the first parameter verified by the control system 34. Such a verification comprises several steps. In a first step, which corresponds to a first step, the temperature sensor 38B measures a temperature of the cryogenic fluid in liquid form L within the storage tank 2, and the control system 34 calculates a theoretical pressure within the storage tank 2 from the temperature measured by the temperature sensor 38B. This theoretical pressure is for example calculated by a theoretical pressure calculator of the control system 34. It corresponds to a pressure if the cryogenic fluid in liquid form L were perfectly mixed within the storage tank 2. In an alternative embodiment, during the first step the pressure sensor 38A of the first measuring device 38 measures a pressure within the storage tank 2, and the control system 34 calculates a theoretical temperature of the cryogenic fluid in liquid form L from the pressure measured by the pressure sensor 38A.

[0079] During a second step, the pressure sensor 38A of the first measuring device 38 records the pressure within the storage tank 2 and the control system 34 compares it to the theoretical pressure calculated during the first step. The control system 34 then obtains a pressure value which corresponds to a difference between the theoretical pressure and the measured pressure. It should be noted that in certain alternative embodiments, the method of use does away with the temperature measurement by the temperature sensor 38B, the pressure sensor 38A then carrying out measurements separated by defined time intervals in order to determine a rate of variation of the pressure within the storage tank 2.In the alternative embodiment mentioned above, during the second step the temperature sensor 38B of the first measuring device 38 records the temperature of the cryogenic fluid in liquid form L within the storage tank 2 and the control system 34 compares it to the theoretical temperature calculated during the first step. The control system 34 then obtains a temperature value which corresponds to a difference between the theoretical temperature and the measured temperature.

[0080] During a third step of the verification of the first parameter, the control system 34 compares the difference between the theoretical pressure and the measured pressure to a known threshold value, which is for example between 20 and 100 millibars. In the alternative embodiment, the control system 34 compares the difference between the theoretical temperature and the measured temperature to a known threshold value.

[0081] In parallel with the verification of the first parameter, the control system 34 carries out the verification of a second parameter, which corresponds to the verification of the pressure at the outlet of the compressor 24.

[0082] The pressure sensor 40 measures the pressure of the gas resulting from the evaporation of the cryogenic fluid in liquid form G at its outlet from the compressor 24. The control system 34 then compares this pressure measured by the pressure sensor 40 to a range of operating pressure values ​​of the consumption and / or treatment system. If the measured pressure is within the range of values, the consumption and / or treatment system 22 receives the gas resulting from the evaporation of the cryogenic fluid in liquid form G that it needs. The control system 34 therefore controls the opening of the control member 36 in order to convey gas resulting from the evaporation of the cryogenic fluid in liquid form G to the storage tank 2 to carry out the bubbling phenomenon there.

[0083] It is understood from the above that when both the first parameter and the second parameter are fulfilled, the control member 36 is opened by the system of control 34 in order to send the gas resulting from the evaporation of the cryogenic fluid in liquid form G into the storage tank 2 for carrying out bubbling. This gas resulting from the evaporation of the cryogenic fluid in liquid form G in the storage tank 2 for carrying out bubbling corresponds to an excess of gas not necessary for the needs of the consumption and / or treatment system 22. Otherwise, the control member 36 remains in its closed state and there is no return of the gas resulting from the evaporation of the cryogenic fluid in liquid form G to the storage tank 2.

[0084] Furthermore, if during the verification of the first parameter it is not fulfilled, the control system 34 orders the closing of the control member 36, even if during the verification of the second parameter it is fulfilled. Conversely, if during the verification of the second parameter it is not fulfilled, the control system 34 orders the closing of the control member 36, even if during the verification of the first parameter it is fulfilled. In other words, the control system 34 implements the opening of the control member 36 provided that the first and second parameters are fulfilled.

[0085] When the control member 36 is in its open state, the compressor 24 can adapt its flow rate and more particularly increase it in order to meet the needs of the consumption and / or treatment system 22 for gas resulting from the evaporation of the cryogenic fluid in liquid form G.

[0086] The present invention thus proposes an installation for storing and treating cryogenic fluid in which the presence of a pipe and a control member makes it possible to use, where appropriate, a gas resulting from the evaporation of the cryogenic fluid in liquid form in order to carry out bubbling used to mix the cryogenic fluid in liquid form when it is stored in a tank.

[0087] The present invention cannot, however, be limited to the means and configurations described and illustrated here and it also extends to any equivalent means and configuration as well as to any technically operative combination of such means.

Claims

Claims

1. Cryogenic fluid storage and treatment installation (1) comprising at least one storage tank (2) for the cryogenic fluid comprising a tank bottom (6) and a tank top (8), a consumption and / or treatment system (22), a loading and / or unloading line (14) for the cryogenic fluid in liquid form (L) configured to connect at least the tank bottom (6) to a storage terminal (12), a supply line (20) for the consumption and / or treatment system (22) with a fuel prepared from a gas resulting from the evaporation of the cryogenic fluid contained in liquid form (G) in the storage tank (2), the supply line (20) connecting at least the tank top (8) to the consumption and / or treatment system (22) and comprising at least one compressor (24) arranged between the storage tank (2) and the consumption and / or treatment system (22),the cryogenic fluid storage and treatment installation (1) comprising a pipe (26) connected at a first end (28) to the supply line (20) between the compressor (24) and the consumption and / or treatment system (22), the pipe (26) being connected by a second end (30) to the bottom of the tank (6), the pipe (26) carrying a control member (36) for the circulation of gas (G) within the pipe (26).,

2. Cryogenic fluid storage and treatment installation (1) according to the preceding claim, in which the second end (30) of the pipe (26) is connected to the loading and / or unloading line (14).

3. Cryogenic fluid storage and treatment installation (1) according to claim 1, in which the second end (30) of the pipe (26) opens into the bottom of the tank (6).

4. Cryogenic fluid storage and treatment installation (1) according to any one of the preceding claims, in which the pipe (26) is configured to be crossed by the gas resulting from the evaporation of the cryogenic fluid (G).

5. Installation for storing and treating cryogenic fluid (1) according to any one of the preceding claims, comprising a first device for measuring pressure within the tank (2) and / or temperature (38) of the cryogenic fluid in liquid form (L) within the tank (2).

6. Cryogenic fluid storage and treatment installation (1) according to the preceding claim, comprising a second pressure measuring device (40) of the gas resulting from the evaporation of the cryogenic fluid (G) at the outlet of the compressor (24).

7. Cryogenic fluid storage and treatment installation (1) according to any one of claims 5 and 6, comprising a control system (34) configured to open or close the control member (36) as a function of a value recorded by the first and / or the second measuring device (38, 40).

8. Work intended for the transport and / or storage of cryogenic fluid, comprising a cryogenic fluid storage and treatment installation (1) according to any one of the preceding claims.

9. Method of using a cryogenic fluid storage and treatment installation (1) according to any one of claims 1 to 7, during which the control member (36) of the pipe (26) is open to send gas resulting from the evaporation of the cryogenic fluid (G) to the bottom of the tank (6) and is closed to prevent the return of gas resulting from the evaporation of the cryogenic fluid (G) to the bottom of the tank (6).

10. Method of use according to the preceding claim in combination with claim 7, during which the opening and closing of the control member (36) are governed by the control system (34).

11. Method of use according to the preceding claim, comprising a first step during which the control system (34) calculates a theoretical pressure within the tank (2) from a temperature measured by the first pressure and / or temperature measuring device (38), a second step during which the control system (34) calculates a difference between the theoretical pressure and an actual pressure measured within the tank (2) by the first pressure and / or temperature measuring device (38), and a third step during which the control system (34) compares the difference to a threshold value.

12. Method of use according to claim 10, comprising a first step during which the control system (34) calculates a theoretical temperature of the cryogenic fluid in liquid form (L) within the tank (2) from a pressure measured by the first pressure and / or temperature measuring device (38), a second step during which the control system (34) calculates a difference between the theoretical temperature and an actual temperature measured within the tank (2) ... pressure and / or temperature (38), and a third step during which the control system (34) compares the deviation to a threshold value.

13. A method of use according to claim 10, comprising a step in which different measurements of the pressure and / or temperature in the storage tank (2) are carried out by the first pressure and / or temperature measuring device (38), and a step in which the control system (34) compares a rate of change of the pressure and / or temperature with a reference value.

14. Method of use according to any one of claims 10 to 13, comprising a comparison phase during which the control system (34) compares a pressure of the gas resulting from the evaporation of the cryogenic fluid (G) measured by the second pressure measuring device (40) at the outlet of the compressor (24) to a range of operating pressure values ​​of the consumption and / or treatment system (22).

15. Method of use according to the preceding claim, in which the control system (34) controls the opening of the control member (36) when the measured pressure is within the range of operating pressure values ​​of the consumption and / or treatment system (22).

16. Method of use according to the preceding claim in combination with claim 11, in which the control system (34) controls the opening of the control member (36) if the difference compared during the third step between the theoretical pressure and the actual pressure measured within the tank (2) by the first pressure and / or temperature measuring device (38) is greater than the threshold value.

17. Method of use according to the preceding claim in combination with claim 12, in which the control system (34) controls the opening of the control member (36) if the difference compared during the third step between the theoretical temperature and the actual temperature measured within the tank (2) by the first pressure and / or temperature measuring device (38) is greater than the threshold value.

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