cryogenic fluid storage and processing facility

Abstract

Title of the Invention: Cryogenic Fluid Storage and Processing Installation. The present invention relates to a cryogenic fluid storage and processing installation (1) comprising at least one storage tank (2), a consumption and / or processing system (22), a loading and / or unloading line (14) for the cryogenic fluid in liquid form (L), a supply line (20) to the consumption and / or processing 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 processing system (22), the pipe (26) being connected to a bottom of the tank (6), the pipe (26) carrying a control device (36) for the flow of gas (G) within the pipe (26).Figure from the summary: Figure 1.

Description

Title of the invention: Cryogenic fluid storage and processing installation

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

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

[0003] Such tanks are nevertheless never perfectly thermally insulated, so evaporation of the cryogenic liquid occurs. This natural evaporation phenomenon is called boil-off, and the gas resulting from this evaporation is called boil-off gas (BOG). The tanks of this work thus contain 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 in contact with the gas resulting from the evaporation of the cryogenic liquid. This hot upper layer induces the formation of vapor within the tank on the one hand and increases the pressure within the tank on the other.

[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 object of the present invention is thus a cryogenic fluid storage and processing installation comprising at least one cryogenic fluid storage tank having a tank bottom and a tank top, a consumption and / or processing system, a cryogenic fluid loading and / or unloading line in liquid form configured to connect at least the tank bottom to a storage terminal, a fuel supply line to the consumption and / or processing system 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 processing system and comprising at least one compressor disposed between the storage tank and the consumption and / or processing system, the cryogenic fluid storage and processing installation comprising a pipeline 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 gas circulation 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, 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 specifically stored in the bottom of the tank, while the gas resulting from the evaporation of the cryogenic liquid is stored in the top of the tank. Here, "bottom of the tank" and "top of the tank" refer to areas of the storage tank, the bottom of the tank corresponding to a lower portion of the tank and the top of the tank corresponding to its upper portion.

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

[0009] In order to fill or empty the tank, the storage and processing installation includes a loading and / or unloading line through which the cryogenic fluid circulates in its liquid form. Depending on the embodiment, the loading and / or unloading line connects the storage tank to a storage terminal, for example, a storage terminal located on a land-based coastline, to a production unit, or to a consumption network. The term "loading or unloading" here means that this line is used either for loading cryogenic fluid from the storage terminal or the production unit into the storage tank, or for unloading cryogenic fluid from the storage tank into the storage terminal or the consumption network, or both for 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 for the storage and treatment plant is configured to be supplied from the tank. Depending on the embodiment, 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 plant includes a supply line connecting the storage tank to the consumption system. and / or processing. This supply line is configured to carry the gas resulting from the evaporation of the cryogenic fluid in liquid form, i.e., the cryogenic fluid in its gaseous state. To supply the consumption and / or processing system with fuel at the appropriate pressure, the supply line is equipped with a compressor, which adjusts the pressure of the gas resulting from the evaporation of the cryogenic fluid in liquid form before it is delivered to the consumption and / or processing system.

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

[0012] The supply 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 top layer within the cryogenic fluid in liquid form in a portion of this cryogenic fluid in liquid form that is in contact with or near the gas, i.e., in contact with or near the tank ceiling, the storage and processing installation is configured to implement a bubbling phenomenon. This bubbling phenomenon consists of creating turbulence within the tank in order to mix the cryogenic fluid in liquid form, and in particular the hot top layer, with the rest of the cryogenic fluid in liquid form.

[0014] The bubbling phenomenon is achieved here by injecting the gas resulting from the evaporation of the cryogenic fluid after it has passed through the compressor. To this end, the storage and treatment installation includes a pipe, the first end of which is located on the supply line between the compressor and the consumption and / or treatment system. This pipe thus diverts at least a portion of the gas resulting from the evaporation of the cryogenic fluid in liquid form that would otherwise be delivered to the consumption and / or treatment system. At its second end, the pipe is connected to the bottom of the tank to inject the gas into the cryogenic fluid in liquid form, in order to achieve optimal mixing of this cryogenic fluid in liquid form. Depending on the embodiment, the pipe is connected to the bottom of the tank directly or indirectly.

[0015] The pipe also carries a control device for the circulation of the gas resulting from the evaporation of the cryogenic fluid in liquid form within the pipe. This control device is a control valve. The control device 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 device, the gas resulting from the evaporation of the cryogenic fluid in liquid form is returned to the bottom of the tank and thus contributes to the bubbling phenomenon.

[0016] According to one embodiment, the presence of the pipe allows the consumption and / or treatment system to be supplied and the bubbling phenomenon to be carried out independently or simultaneously.

[0017] According to an optional feature 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 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 flows through the loading and / or unloading line through which the cryogenic fluid in liquid form otherwise circulates. This reduces costs and space requirements by reusing a line already present within the architecture of the storage and processing facility. The use of the loading and / or unloading line is possible even outside of operations involving loading or unloading the cryogenic fluid in liquid form into the tank. In such cases, the loading and / or unloading line empties by gravity or by purging the gas into the storage tank and can therefore be used to circulate the gas resulting from the evaporation of the cryogenic fluid in liquid form.

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

[0021] According to an optional feature 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 leads directly to the bottom of the tank. The gas resulting from the evaporation of the cryogenic fluid in liquid form then circulates in a dedicated pipe. This allows the bubbling phenomenon to occur even during the loading and / or unloading of the cryogenic fluid in liquid form.

[0023] According to an optional feature of the invention, the conduit is configured to be traversed by the gas resulting from the evaporation of the cryogenic fluid.

[0024] According to an optional feature of the invention, the cryogenic fluid storage and processing installation includes a first device for measuring pressure within the tank and / or 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 throughout the tank, for example by taking a measurement in the tank head, 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 feature of the invention, the cryogenic fluid storage and processing installation includes 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 feature of the invention, the cryogenic fluid storage and processing installation includes a control system configured to open or close the control unit based on a value read by the first and / or second measuring device.

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

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

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

[0032] The invention further relates to a method of using a cryogenic fluid storage and processing installation according to any one of the preceding claims, during which the control device of the line is opened to send gas from the evaporation of the cryogenic fluid to the bottom of the tank and is closed to prevent the return of gas from the evaporation of the cryogenic fluid to the bottom of the tank.

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

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

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

[0036] According to an optional feature of the invention, the method of use includes a first step in 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 in 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 in which the control system compares the difference to a threshold value.

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

[0038] According to an optional feature of the invention, the method of use includes a first step in 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 in 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 in 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 feature of the invention, the method of use includes 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 processing system.

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

[0042] According to an optional feature of the invention, the control system commands the opening of the control element 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 processing system, the control system commands the control element 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 flows through the pipe to the storage tank where it undergoes bubbling. The control element, in its open state, is either partially open or fully open depending on the requirements. Outside the aforementioned range of values, the control element is in its closed state and bubbling does not occur. 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 processing system does not require it as fuel.

[0044] According to an optional feature 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 inside the tank by the first pressure and / or temperature measuring device is greater than the threshold value.

[0045] The return of gas 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 thus requires bubbling to mix the cryogenic fluid in liquid form and reduce the pressure. For example, the control system commands the opening of the control device if there is a difference of at least 20 mbar between the theoretical pressure and the actual measured pressure.

[0046] According to an optional feature 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 inside the tank by the first pressure and / or temperature measuring device is greater than the threshold value.

[0047] By way of example, the control system commands the opening of the control device 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 feature of the invention, the method of use includes 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 to a reference value.

[0049] In other words, the control system commands the opening of the control device and therefore the implementation of bubbling when, from measurements of pressure and a derivative of these pressure values, or from measurements of temperature and 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 feature of the invention, the control system commands the closure of the control element if the difference compared during the third step between the theoretical pressure and the actual pressure measured inside the tank by the first pressure and / or temperature measuring device is less than the threshold value.

[0051] According to an optional feature of the invention, the control system commands the closure of the control element if the difference compared during the third step between the theoretical temperature and the actual temperature measured inside 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 temperature within the storage tank reach values ​​which do not require the implementation of the bubbling process, the control system orders the closure of the control device, 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 device.

[0053] Other features, details and advantages of the invention will become clearer upon reading the following description on the one hand, and the illustrative and non-limiting examples of embodiments given with reference to the accompanying drawings on the other hand, in which:

[0054] [Fig.l] illustrates, schematically, a cryogenic fluid storage and transport installation, here represented according to a first embodiment in which a pipe is connected at one end to a supply line and at one 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 the [Fig.1];

[0056] [Fig.3] illustrates, schematically, a second embodiment of the installation storage and transport of the [Fig.l], in which the pipe is connected at 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 different embodiments of the invention can be combined in various ways, provided they are not incompatible or mutually exclusive. In particular, variants of the invention may be conceived comprising only a selection of features, described hereafter in isolation from the other described features, 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 schematically illustrate a storage and processing installation 1 according to the invention, such a storage and processing installation 1 being here integrated within a structure such as a floating structure or a land-based structure.

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

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

[0062] In the figures, the storage and treatment installation 1 here presents 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 presents 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 area 6, which corresponds, for example, to at least half the height of the storage tank 2 measured perpendicularly 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 ceiling 8, which corresponds to its highest portion. The tank ceiling 8 extends from a ceiling wall 10 opposite the bottom wall 4.

[0064] The storage and processing installation 1 is connected to a storage terminal 12 located outside the structure, for example on a coastline. The storage terminal 12 is given here for illustrative purposes only; it could be envisaged, without departing from the scope of the invention, that the storage and processing installation 1 is instead connected to a production unit or to a consumption network. The storage terminal 12 allows for the storage of at least cryogenic fluid in liquid form L. In some embodiments, the storage terminal 12 allows for the storage of 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 processing installation 1 is more specifically connected to the storage terminal 12 at least by means of a loading and / or unloading line 14. This loading and / or unloading line 14 allows the cryogenic fluid in liquid form L to circulate 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. More specifically, the loading and / or unloading line 14 comprises a first pipe 16A, a second pipe 16B, and a third pipe 16C which extend at least partially into the storage tank 2. In a case not shown, the line 16C is not present in the installation. These pipes are branches on 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 pipe 16A is connected to the main line of the loading and / or unloading line 14 at the second intersection 17B, the third pipe 16C being itself connected to the first pipe 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, near the bottom wall 4. The second pipe 16B is equipped with a pump 18, which facilitates the discharge of the cryogenic fluid in liquid form L. The pump 18 is located 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 located three meters away from it. In contrast, the third pipe 16C opens into the top of the tank 8, near the ceiling wall 10. The presence of pipes 16 opening at different heights in the storage tank 2 facilitates the loading of the cryogenic fluid in liquid form L, which can thus be carried out by one or both of the first pipe 16A and the third pipe 16C.

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

[0069] According to the invention, the storage and processing 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 specifically, 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 processing system 22. It is understood that the pipe 26 constitutes a means for the gas resulting from the evaporation of the cryogenic fluid in liquid form G to bypass the consumption and / or processing system 22.

[0070] The gas resulting from the evaporation of the cryogenic fluid in liquid form G circulating within the line 26 is intended to be returned to the storage tank 2. For this purpose, the second end 30 of the line 26 is connected to the storage tank 2 and more specifically to the bottom of the tank 6. The second end 30 is, according to the methods of embodiment, connected directly or indirectly to the bottom of tank 6. Thus, [Fig.1] illustrates a first embodiment, [Fig.2] illustrates a variant of the first 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 flow within the main line 13 of the loading and / or unloading line 14; rather, it flows through a dedicated conduit 32. This dedicated conduit 32 is a portion of the pipe 26 arranged parallel to the main line 13.

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

[0073] Regardless of the embodiment, the storage and processing installation 1 is equipped with a control system 34. This control system 34 is configured to decide whether the gas from the evaporation of the cryogenic fluid in liquid form G should be delivered to the consumption and / or processing system 22 or returned to the storage tank 2. The control system controls for this purpose a control element 36 located on the pipe 26. This control element 36 here takes the form of a valve which has either a closed state in which the passage of gas 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 from the evaporation of the cryogenic fluid in liquid form G is allowed.It is understood that in the closed state of the control device 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, whereas in its open state, on the contrary, the gas resulting from the evaporation of the cryogenic fluid in liquid form G can be partly 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 of the control device 36 from the closed state to the open state or conversely, 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. to a bubbling phenomenon which will be described in more detail below in relation to a method of using the storage and treatment facility 1.

[0074] The control system 34 decides whether to open or close the control device 36 based on certain parameters measured or calculated within the storage and processing installation 1. To do this, the storage and processing installation 1 includes various measuring devices. Among these measuring devices, the storage and processing installation 1 has a first measuring device 38, or first pressure and / or temperature measuring device 38, configured to measure values ​​within the storage tank 2, and a second measuring device 40, or second pressure measuring device 40, configured to measure 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 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 is a pressure sensor.

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

[0077] During the operating process, the control element 36 is opened 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 checked by the control system 34 prior to the control element being in its open state.

[0078] Checking the pressure within the storage tank 2 corresponds to the first parameter checked by the control system 34. Such a check involves several steps. Initially, which corresponds to the first step, the temperature sensor 38B measures the 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 the 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] In a second step, the pressure sensor 38A of the first measuring device 38 measures the pressure within the storage tank 2, and the control system 34 compares it to the theoretical pressure calculated in the first step. The control system 34 then obtains a pressure value that corresponds to the difference between the theoretical pressure and the measured pressure. It should be noted that in some alternative embodiments, the method of use dispenses with the temperature measurement by the temperature sensor 38B; the pressure sensor 38A then performs measurements separated by defined time intervals in order to determine the rate of change 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 measures 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 operates 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 ​​for the consumption and / or processing system. If the measured pressure is within this range, the consumption and / or processing system 22 receives the required gas from the evaporation of the cryogenic fluid in liquid form G. The control system 34 therefore commands the opening of the control device 36 to convey the gas from the evaporation of the cryogenic fluid in liquid form G to the storage tank 2 to perform the bubbling process.

[0083] It is understood from the above that when both the first and second parameters are met, the control element 36 is opened by the control system 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 bubbling. This gas resulting from the evaporation of the cryogenic fluid in liquid form G into the storage tank 2 for bubbling corresponds to an excess of gas not required by the consumption and / or treatment system 22. Otherwise, the control element 36 remains closed 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 the first parameter is not met during the check, the control system 34 orders the control element 36 to close, even if the second parameter is met during the check. Conversely, if the second parameter is not met during the check, the control system 34 orders the control element 36 to close, even if the first parameter is met during the check. In other words, the control system 34 opens the control element 36 only if both the first and second parameters are met.

[0085] When the control element 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 in gas resulting from the evaporation of the cryogenic fluid in liquid form G.

[0086] The present invention thus proposes a cryogenic fluid storage and treatment installation in which the presence of a pipe and a control device allows the use, where appropriate, of a gas 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 is not limited to the means and configurations described and illustrated herein, and extends also to any equivalent means and configuration as well as to any technically operative combination of such means.

Claims

Demands

1. Cryogenic fluid storage and processing installation (1) comprising at least one cryogenic fluid storage tank (2) having a tank bottom (6) and a tank top (8), a consumption and / or processing system (22), a cryogenic fluid loading and / or unloading line (14) in liquid form (L) configured to connect at least the tank bottom (6) to a storage terminal (12), a supply line (20) to the consumption and / or processing 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 processing system (22) and comprising at least one compressor (24) disposed between the storage tank (2) and the consumption and / or processing system (22),the cryogenic fluid storage and processing 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 processing system (22), the pipe (26) being connected at a second end (30) to the bottom of the tank (6), the pipe (26) carrying a control device (36) for the gas circulation (G) within the pipe (26), the second end (30) of the pipe (26) being connected to the loading and / or unloading line (14).

2. Cryogenic fluid storage and processing installation (1) according to the preceding claim, wherein the conduit (26) is configured to be traversed by the gas resulting from the evaporation of the cryogenic fluid (G).

3. Installation for the storage and processing of 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).

4. Cryogenic fluid storage and processing 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).

5. Cryogenic fluid storage and processing installation (1) according to any one of claims 3 and 4, comprising a control system (34) configured to open or close the control member (36) as a function of a value read by the first and / or second measuring device (38, 40).

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

7. A method of using a cryogenic fluid storage and processing installation (1) according to any one of claims 1 to 5, wherein the control device (36) of the line (26) is opened to send gas from the evaporation of the cryogenic fluid (G) to the bottom of the tank (6) and is closed to prevent the return of gas from the evaporation of the cryogenic fluid (G) to the bottom of the tank (6).

8. Method of use according to the preceding claim in combination with claim 5, wherein the opening and closing of the control member (36) are governed by the control system (34).

9. A method of use according to the preceding claim, comprising a first step in 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 in 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 in which the control system (34) compares the difference to a threshold value.

10. A method of use according to claim 8, comprising a first step in 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 in which the control system (34) calculates a difference between the theoretical temperature and an actual temperature measured within the tank (2) by the first device pressure and / or temperature measurement (38), and a third step in which the control system (34) compares the deviation to a threshold value.

11. A method of use according to claim 8, comprising a step in which different measurements of 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 pressure and / or temperature to a reference value.

12. A method of use according to any one of claims 8 to 11, comprising a comparison phase during which the control system (34) compares a pressure of the gas 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 processing system (22).

13. A method of use according to the preceding claim, wherein the control system (34) commands 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).

14. A method of use according to the preceding claim in combination with claim 9, wherein the control system (34) commands 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.

15. A method of use according to the preceding claim in combination with claim 10, wherein the control system (34) commands 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.

Images