Power supply and cooling systems for floating structures

Abstract

The present invention relates to a power supply and cooling system (1) for a floating structure comprising a tank (2), comprising a supply circuit (3) with at least one compression device (10) configured to supply gas to gas consuming devices (5, 6), and a cooling circuit (4) with a heat exchanger (17) configured to participate in managing the internal pressure of the tank (2), the cooling circuit (4) being connected to the supply circuit (3) on both sides of the compression device (10), characterized in that the compression device (10) comprises two compression stages (30, 31), and the power supply and cooling system (1) comprises a control device (9) configured to connect the compression stages (30, 31) in series or in parallel.

Description

Technical Field

[0001] The present invention relates to the field of floating structures for storing and / or transporting gases in a liquid state, and more particularly to a gas supply and cooling system installed within such a floating structure.

Background Art

[0002] During navigation by a ship equipped with a tank for a gas in a liquid state intended to be delivered to a destination, the ship may be used to supply at least a part of the gas in the liquid state to at least one engine of the ship via a gas supply system. At the same time, it is necessary to keep the pressure inside the tank at an acceptable level, particularly by keeping the cargo gas in a liquid state at an appropriate temperature.

[0003] In this regard, it is known to use a supply circuit that sucks in the evaporated gas and then compresses it to enable its supply to one or more engines. In parallel or alternatively, the pressure inside the tank can be reduced by a cooling circuit that circulates a refrigerant to re-liquefy a part of the gas evaporated inside the tank.

[0004] These two circuits are often found within a floating structure, resulting in a non-negligible size and cost. Therefore, one objective is to improve the supply and cooling system in order to reduce said size and cost. By reducing the size, it is also possible to limit the number of lines within the circuit. Therefore, the maintenance of these circuits is simplified and malfunctions that may occur in one circuit or the other are detected more quickly.

Summary of the Invention

Problems to be Solved by the Invention

[0005] One existing solution is to install a compressor that allows for both the compression of the gas intended to be supplied to the engine and the compression of the refrigerant, in order to limit the number of compressors required. However, the gas supplied to the engine and the refrigerant do not meet the same compression requirements to ensure their respective functions. [Means for solving the problem]

[0006] The present invention solves this problem with a gas supply and cooling system for a floating structure comprising at least one tank configured to contain gas, - A supply circuit, intended for the passage of gas arriving from a tank, comprising at least one compressor, the supply circuit being configured to supply gas to at least one gas consumption device mounted on a floating structure, with the compressor connected to the headspace of the tank. - A cooling circuit, including at least one cooling circuit intended for the passage of a refrigerant, comprising at least one heat exchanger configured to be involved in managing the internal pressure of a tank, an internal heat exchanger, and a turbo compressor comprising a compression member located upstream of a first path of the internal heat exchanger and a turbine located downstream of the first path of the internal heat exchanger, wherein the compression member and the turbine are rotatably connected by a shaft, and the cooling circuit is connected to a supply circuit on both sides of the compressor. In a supply and cooling system comprising, The compressor comprises at least two compression stages, and the supply and cooling system comprises a control device configured to connect the compression stages in series when the compressor supplies fluid to a gas consumption device, and to connect the compression stages in parallel when the compressor supplies fluid to a cooling circuit. This can be solved by proposing a supply and cooling system characterized by the above features.

[0007] The role of the cooling circuit is to cool the gas contained in the tank by managing the internal pressure of the tank.

[0008] Therefore, such a supply and cooling system, with the assistance of a single compressor, can ensure both the function of supplying gas to a gas consumption device and the function of managing the internal pressure of the tank. The fact that the compression stages of the compressor can be arranged in series or in parallel makes it possible to optimally compress any fluid circulating through the compressor, regardless of the properties of the fluid and / or the destination of the fluid.

[0009] If the fluid being compressed by the compressor is a gas arriving from a tank and intended to be supplied to a gas consumption device, the compression stages of the compressor are arranged in series so that the gas pressure takes precedence over the flow through the compressor.

[0010] If the fluid compressed by the compressor is a refrigerant that enables pressure control of the tank, the compression stages of the compressor are arranged in parallel, and the flow of the refrigerant through the compressor takes precedence over the pressurization of the refrigerant.

[0011] During the transport of gas cargo in liquid form, the gas in liquid form may partially evaporate naturally or inductively within the tank and be supplied to the gas consumption equipment. To reduce the internal pressure of the tank, the gas in vapor form may be exhausted through the supply circuit or recondensed directly or indirectly through the cooling circuit and delivered back into the tank.

[0012] The compressor compresses the gas that has circulated from the tank to the supply circuit. The compressed gas may then flow to a gas consumption device and be supplied to the gas consumption device, or it may flow to a cooling circuit and act as a refrigerant. The refrigerant may also be another fluid used solely as a refrigerant. Such another fluid may also be compressed by the compressor.

[0013] The compression member and the turbine are rotationally driven by their mechanical connection. The turbine is rotationally driven, which in turn rotates the shaft, and the shaft itself rotates the compression member. Thus, the refrigerant is first compressed by the compression member. Next, the refrigerant expands as it passes through the internal heat exchanger via the first path and then through the turbine. The refrigerant then passes through the heat exchanger, thereby enabling the control of the internal pressure of the tank. Thus, it is understood that the refrigerant circulating in the cooling circuit is involved in the cooling of the liquid gas contained in the tank via the heat exchanger.

[0014] The control device allows the compression stages to be connected in series or parallel, depending on the properties of the fluid circulating through the compressor, or according to the needs to which the supply and cooling systems must respond.

[0015] According to one feature of the present invention, control Device The compressor has a main line through which each compression stage passes. When the compression stages are connected in series, the fluid compressed by the compressor circulates through the main line and passes through each compression stage.

[0016] According to one feature of the present invention, control Device The system comprises at least one peripheral line connected to a main line and at least one valve controlling the flow circulating in the peripheral line, the peripheral line bypassing the compression stages. The peripheral line bypasses each compression stage, and in particular allows the compression stages to be connected in parallel with one another. Thus, the fluid circulates only partially within the main line and is separated into the same number of parts as there are compression stages, each part circulating within the peripheral line while bypassing the compression stages. The series or parallel connection is made by opening and closing the valve, which determines whether to allow access to the main line and / or the peripheral line, thereby enabling bypassing the compression stages.

[0017] According to one feature of the present invention, the internal heat exchanger comprises a first path and a second path that exchange heat with each other, the first path being located upstream of the heat exchanger and the second path being located downstream of the heat exchanger. Thus, the internal heat exchanger allows the refrigerant to be pre-cooled before it passes through the turbine. After leaving the heat exchanger, the refrigerant passes through the second path of the internal heat exchanger, regulating the temperature within the cooling circuit.

[0018] According to one feature of the present invention, the compressor of the supply circuit is a first compressor, and the supply and cooling system comprises a second compressor installed in parallel with the first compressor. By installing the two compressors in parallel, it is possible to ensure the function of the supply and cooling system even if, for example, one of the compressors fails. By installing the two compressors, it is also possible to simultaneously ensure the supply to the gas consumption device and the management of the internal pressure of the tank. Each compressor is assigned to its own specific needs. Both compressors can also be assigned to the same need.

[0019] According to one feature of the present invention, the second compressor comprises at least two compression stages, and the control device is configured to connect the compression stages of the second compressor in series when the second compressor supplies fluid to a gas consumption device, and to connect the compression stages of the second compressor in parallel when the second compressor supplies fluid to a cooling circuit. In other words, the structure of the second compressor is identical to that of the first compressor. Therefore, the second compressor can also supply fluid to a gas consumption device or a cooling circuit.

[0020] According to one feature of the present invention, the supply and cooling system comprises a circuit for liquid gas, configured to take in liquid gas contained in the tank, and intended for liquid gas arriving from the tank to pass through, and a heat exchanger performs heat exchange between the liquid gas in the circuit for liquid gas and a refrigerant circulating in the cooling circuit. Such operation is intended to manage the saturation pressure of the tank by limiting the presence of vapor gas in the tank's headspace. The liquid gas can be pumped, for example, and circulated within the circuit for liquid gas. The liquid gas is cooled by the refrigerant and continues to act on the pressure in the tank. As the liquid gas is cooled by the cooling circuit, the gas is subsequently at a lower temperature than the liquid gas contained in the tank. Therefore, the return of the cooled gas lowers the average temperature of the tank, which also ensures a decrease in the saturation pressure of the tank.

[0021] According to one feature of the present invention, a circuit for a liquid gas comprises a member for spraying the liquid gas into the headspace of a tank and an outlet opening located in the lower part of the tank. The liquid gas is cooled by a refrigerant via a heat exchanger and then sprayed into the tank headspace in the form of a mist. By spraying the cooled liquid gas into the tank headspace with the spraying member, it is possible to at least partially condense the vapor gas present in the tank headspace. Thus, by condensing the vapor gas, it is possible to reduce the pressure inside the tank. The cooled liquid gas can also be returned to the lower part of the tank.

[0022] According to one feature of the present invention, the supply and cooling system comprises a return line connected to the supply circuit downstream of the compression device and extending to the circuit for the gas in the liquid state, and the supply and cooling system comprises a first heat exchanger for performing heat exchange between the gas circulating in the return line and the gas circulating in the circuit for the gas in the liquid state. The gas in the vapor state may be delivered to the gas consuming device in an excessive amount, or may be present in an excessive amount in the headspace of the tank so that the cooling circuit can completely condense the gas in the vapor state.

[0023] When the gas in the vapor state is delivered to the gas consuming device, the excess gas may, for example, be burned or released into the atmosphere. The return line makes it possible to provide an alternative means for this loss by circulating the excess gas to the circuit for the gas in the liquid state and returning the excess gas to the tank.

[0024] In order to condense the gas in the vapor state circulating in the return line, the heat exchange is performed between the gas circulating in the return line and the gas in the liquid state circulating in the circuit for the gas in the liquid state, which is cooled by passing through the heat exchanger. Thus, the heat exchanger functions as a condenser for the gas circulating in the return line. When this heat exchange is performed, the condensed gas may return to the tank through the outlet opening or may be sprayed by the spraying member.

[0025] According to one feature of the present invention, the supply and cooling system comprises a second heat exchanger for performing heat exchange between the gas circulating in the supply circuit upstream of the compression device and the gas circulating in the return line upstream of the first heat exchanger. The gas circulating in the supply line exiting the tank is at a lower temperature than the gas circulating in the return line. Thus, the second heat exchanger makes it possible to precool the gas circulating in the return line before the gas circulating in the return line is condensed by passing through the first heat exchanger.

[0026] According to one feature of the present invention, the heat exchanger is arranged at least partially in the headspace of the tank, i.e., extending into the tank. This is an alternative embodiment that does not have a circuit for the gas in the liquid state. Thus, instead of cooling the gas in the liquid state that circulates in the circuit for the gas in the liquid state, the heat exchanger is arranged directly in the headspace of the tank and acts as a condenser for the gas in the vapor state present in the headspace of the tank. The heat exchanger may be, for example, a gravity condenser. Thus, the refrigerant circulates within the spiral body and thus condenses the surrounding vaporous gas from the headspace of the tank. When condensed, the gas in the liquid state merges with the liquid portion of the cargo.

[0027] The present invention also encompasses a method for managing the gas contained in a tank, implemented by a supply and cooling system according to any one of the前述 features, comprising: - a first step of determining the need to supply a gas-consuming device or the need to manage the pressure inside the tank; - a second step of connecting the compression stages of the compression device in series or in parallel by control Device depending on the determined need. Thus, such a method makes it possible to adapt the type of connection between the compression stages of the compression device to a given need.

[0028] According to one feature of the method, according to the first operating mode, the first compression device has its compression stages connected in series to fluidly supply a gas-consuming device, while the second compression device has its compression stages connected in parallel to fluidly supply a cooling circuit.

[0029] According to one feature of the method, according to the second operating mode, the first compression device and the second compression device have their compression stages connected in series to fluidly supply a gas-consuming device.

[0030]

[0031] ​According to one feature of the method, according to the third operating mode, the first and second compressors are connected in parallel to each other in their compression stages to supply fluid to the cooling circuit.

[0032] Other features and advantages of the present invention will become apparent, on the one hand, through the following description and on the other hand, through several exemplary embodiments given as non-limiting representations with reference to the attached schematic diagrams. [Brief explanation of the drawing]

[0033] [Figure 1] This is an overall diagram of a first embodiment of the supply and cooling system according to the present invention. [Figure 2] This diagram shows the structure of a compressor located within a supply and cooling system. [Figure 3] This figure shows the first configuration of the compression stage of the compression device. [Figure 4] This figure shows the second configuration of the compression stage of the compression device. [Figure 5] This is an overall diagram of a second embodiment of the supply and cooling system. [Figure 6] This figure shows the first operating mode of a second embodiment of the supply and cooling system. [Figure 7] This figure shows the second operating mode of the second embodiment of the supply and cooling system. [Figure 8] This figure shows the third operating mode of the second embodiment of the supply and cooling system. [Figure 9] This is an overall diagram of a third embodiment of the supply and cooling system. [Modes for carrying out the invention]

[0034] Figure 1 shows a supply and cooling device 1, which can be placed within a floating structure, for example, a tank 2, capable of transporting and / or storing gas in liquid form. This gas is, for example, natural gas. The gas in liquid form is stored in tank 2 at a very low temperature. For various reasons, for example naturally during transport, the gas in liquid form may partially evaporate in the headspace 200 of tank 2. This evaporation of gas causes an increase in the internal pressure of tank 2. Such an increase in internal pressure needs to be regulated, for example, by venting the vaporized gas that has formed in the headspace 200 of the tank from tank 2. Alternatively, the evaporated gas can be recondensed, resulting in the evaporated gas returning to a liquid form, which leads to a decrease in the internal pressure of tank 2.

[0035] The supply and cooling system 1 includes a supply circuit 3, which is configured to draw in evaporated gas formed in the headspace 200 of the tank 2. The gas can then be used as fuel for a first gas consumption device 5 and / or a second gas consumption device 6. For example, the first gas consumption device 5 may be an engine that enables the propulsion of the floating structure, and the second gas consumption device 6 may be an auxiliary motor responsible for supplying power to the floating structure.

[0036] To adjust the pressure of the gas circulating in the supply circuit 3 and raise the gas pressure to a level suitable for the gas consumption device, the supply circuit 3 includes a compressor 10 that ensures the compression of the gas. The compressor 10 can then supply the fluid to the gas consumption device. If the gas consumption device does not require energy supply via the gas, this gas can be removed, for example, by a burner 7.

[0037] The supply and cooling system also includes a cooling circuit 4. The cooling circuit 4 is configured to be directly or indirectly involved in the pressure management of the tank 2. The cooling circuit 4 is configured to circulate a refrigerant, which may be, for example, a gas drawn into the supply circuit 3, or another refrigerant.

[0038] The cooling circuit 4 is connected to the supply circuit 3, and more specifically, to the upstream and downstream of the compressor 10. Therefore, the compressor 10 can be involved in the circulation and compression of the refrigerant.

[0039] From the above, it can be understood that the compressor 10 may be involved in the operation of the supply circuit 3 or the cooling circuit 4. The determination of such operation may depend, for example, on the position and connection to the cooling circuit 4 of the first valve 41 located in the supply circuit 3 upstream of the compressor 10, the position and connection to the cooling circuit 4 of the second valve 42 located in the supply circuit 3 downstream of the compressor 10, the position and connection to the supply circuit 3 of the third valve 43 located in the cooling circuit 4 downstream of the compressor 10, and the position and connection to the supply circuit 3 of the fourth valve 44 located in the cooling circuit 4 upstream of the compressor 10.

[0040] Therefore, when the first valve 41 and the second valve 42 are in the open position and the third valve 43 and the fourth valve 44 are in the closed position, the compressor 10 is incorporated into the supply circuit 3 for the purpose of compressing gas and supplying it to the gas consumption device.

[0041] When the first valve 41 and the second valve 42 are in the closed position and the third valve 43 and the fourth valve 44 are in the open position, the compressor 10 is incorporated into the cooling circuit 4 for the purpose of compressing the refrigerant and participating in the management of the pressure in the tank 2.

[0042] The cooling circuit 4 comprises a turbo compressor 13, an internal heat exchanger 18, and a heat exchanger 17. The turbo compressor 13 comprises a compression member 14 and a turbine 15, which are mechanically connected to each other by a shaft 16. The compression member 14 is located upstream of a first path in the internal heat exchanger 18, while the turbine 15 is located downstream of this same first path in the heat exchanger 18. The turbine 15 is rotated, which in turn drives the shaft 16, and the shaft 16 itself drives the compression member 14. Thus, the refrigerant is first compressed by the compression member 14, then passes through the first path in the internal heat exchanger 18, and subsequently expands by the turbine 15. The expansion makes it possible to lower the temperature of the refrigerant as it circulates through the heat exchanger 17 and then through a second path in the internal heat exchanger 18. Therefore, heat exchange occurs between the refrigerant circulating in the first path of the internal heat exchanger 18 and the refrigerant circulating in the second path of the internal heat exchanger 18, and the temperature of the refrigerant circulating in the cooling circuit 4 is adjusted.

[0043] The supply and cooling system 1 also includes a circuit 8 for liquid gas, through which the liquid form of the gas arriving from tank 2 circulates. The circuit 8 for liquid gas allows for the condensation of the gas evaporated in the headspace 200 of tank 2, and thus participates in managing the tank pressure.

[0044] The liquid gas in tank 2 is drawn into the liquid gas circuit 8 by pump 19. The liquid gas then circulates and passes through heat exchanger 17. Thus, the heat exchange taking place in heat exchanger 17 is understood to be between the refrigerant circulating in cooling circuit 4 and the liquid gas circulating in the liquid gas circuit 8. The liquid gas is then cooled and discharged from heat exchanger 17.

[0045] After cooling, the gas in liquid form can return to the lower part of tank 2 through the outlet opening 21. This action lowers the average temperature of tank 2, which in turn leads to a decrease in the saturation pressure of tank 2 and consequently a decrease in the overall pressure of tank 2.

[0046] The cooled liquid gas may also be sprayed in the form of a mist into the headspace 200 of tank 2. To do this, the circuit for the liquid gas includes a spray member 20 for spraying the liquid gas. By spraying the liquid gas, it is possible to condense the evaporated gas in the headspace 200 of tank 2. Thus, the condensation of the gas reduces the amount of evaporated gas, and therefore this results in a decrease in the internal pressure of tank 2. To determine whether or not to allow circulation of the liquid gas, the circuit for the liquid gas includes an additional valve 51.

[0047] Figure 2 schematically shows the internal structure of the compressor 10. Compression of the fluid within the compressor can be carried out in various ways, depending on the needs to be met by the supply and cooling systems. The fluid is compressed by multiple compression stages within the compressor 10. In Figure 2, the compressor 10 comprises a first compression stage 30 and a second compression stage 31. A cooler 35 follows each compression stage. The compressor 10 may comprise three or more compression stages.

[0048] Compression stages can be connected to each other in series or in parallel. Such connections are control Device This is done via 9. Control Device 9 comprises a main line 32 extending from one end to the other of the compression device 10. The first compression stage 30 and the second compression stage 31 are both located on the main line 32.

[0049] control Device 9 also includes a first peripheral line 33 connected to the main line 32 via a first connection located upstream of the first compression stage 30 and a second connection located downstream of the cooler 35 of the first compression stage 30. Thus, the first peripheral line 33 is configured to circulate gas to the first peripheral line 33 that bypasses the first compression stage 30. The first peripheral line includes a first valve 36.

[0050] control Device 9 also includes a second peripheral line 34 connected to the main line 32 via a first connection located downstream of the cooler 35 of the first compression stage 30 and a second connection located downstream of the cooler 35 of the second compression stage 31. Thus, the second peripheral line 34 is configured to circulate the gas to the second peripheral line 34, bypassing the first compression stage 30.

[0051] The second connection of the first peripheral line 33 is located downstream of the first connection of the second peripheral line 34. Therefore, the gas that has circulated through the first peripheral line 33 cannot subsequently circulate through the second peripheral line 34. The first connection of the second peripheral line 34 includes a second valve 37, which may be, for example, a three-way valve.

[0052] Figure 3 shows the first configuration of the compression stage of the compression device 10. In Figures 3 and 4, control Device The solid line representing line 9 indicates that the fluid is controlled Device Line 9 corresponds to a circulating line, while the dotted line corresponds to a line where the fluid does not circulate. In this first configuration, the compression stages are connected in series with each other. The series connection of the compression stages is intended so that the gas circulating through the compressor 10 is supplied to the gas consumption device shown in Figure 1, and the control Device This is achieved by 9. When the gas is intended to be supplied to the gas consumption device, the gas pressure must take precedence over the flow rate. Therefore, the gas must be compressed by all compression stages, and it is more appropriate to connect the compression stages in series.

[0053] When the compression stages are connected in series, the first valve 36 is closed. Therefore, the gas circulates only within the main line 32, is compressed by the first compression stage 30, and then passes through the cooler 35 of the first compression stage 30. Next, the gas reaches the second valve 37, which maintains the circulation of the gas within the main line 32, and as a result, the gas is compressed by the second compression stage 31, then passes through the cooler 35 of the second compression stage 31, and exits the compressor 10.

[0054] Figure 4 shows a second configuration of the compression stages of the compressor 10. In Figure 4, the compression stages are arranged in parallel with each other. Parallel arrangement is shown when the compressor 10 compresses a refrigerant intended to circulate within the cooling circuit, and the flow rate of the refrigerant takes precedence over the pressure of the refrigerant. In this second configuration of the compression stages, the control module 9 opens a first valve 36 located in the first peripheral line 33.

[0055] In this configuration, the refrigerant circulates within the main line 32 and is separated into two parts. The first part continues its circulation within the main line 32, is compressed by the first compression stage 30, and then passes through the cooler 35 of the first compression stage 30. The second part circulates within the first peripheral line 33, bypassing the first compression stage 30. Next, the second part reaches the main line 32, is compressed by the second compression stage 31, and is cooled by the cooler 35 of the second compression stage 31.

[0056] The first portion of refrigerant reaches the second valve 37, which directs the refrigerant to the second peripheral line 34, thereby bypassing the second compression stage 31.

[0057] Therefore, the two refrigerant sections are each compressed by the compression stage. By connecting the compression stages in parallel, a higher fluid flow rate is guaranteed than with a series connection.

[0058] Figure 5 shows a second embodiment of the supply and cooling system 1. This second embodiment differs from the first embodiment in that it includes a first compressor 11 and a second compressor 12. The first compressor 11 is installed in the supply circuit 3, while the second compressor 12 is installed in the cooling circuit 4. However, as will be explained in more detail later, the function of the two compressors is not defined by their location.

[0059] The presence of two compressors also makes it possible to establish redundancy within the supply and cooling system 1. Therefore, for example, even if one compressor fails, the other compressor can still perform its function and maintain the operation of the supply and cooling system 1.

[0060] Both the supply circuit 3 and the cooling circuit 4 are equipped with multiple valves that allow each circuit to access the respective compressor, and as a result the compressor can satisfy both the need to supply gas to the gas consumption device or, if necessary, the need to supply refrigerant to the cooling circuit. Thus, in addition to the four valves already found in the first embodiment, the second embodiment of the supply and cooling system 1 is equipped with a fifth valve 45, a sixth valve 46, a seventh valve 47, an eighth valve 48, a ninth valve 49, and a tenth valve 50.

[0061] The fifth valve 45 and the sixth valve 46 allow the connection of the first compressor 11 to the cooling circuit 4 or the connection of the second compressor 12 to the supply circuit 3, depending on the configuration of the supply and cooling system 1.

[0062] The seventh valve 47 and the eighth valve 48 are located on either side of the first compressor 11 and allow the first compressor 11 to be isolated when they are in the closed position. Closing these valves is useful in case the first compressor 11 fails. The ninth valve 49 and the tenth valve 50 allow their parts to isolate the second compressor 12 from the rest of the supply and cooling system 1.

[0063] The supply and cooling system 1 also includes a return line 60 connected to the supply circuit 3 upstream of the second gas consumption device 6 and upstream of the burner 7. The return line 60 allows for the recirculation of excess gas that circulates within the supply line 3 and is not needed for consumption by the gas consumption device. Thus, instead of being removed by the burner 7, the gas circulates through the return line and returns to the tank 2.

[0064] To recondense the gas circulating in the return line 60, the supply and cooling system 1 includes a first heat exchanger 61 and a second heat exchanger 62. The first heat exchanger 61 exchanges heat between the gas circulating in the return line 60 and the cooled liquid gas circulating in the circuit 8 for liquid gas, and a branch may be arranged in the circuit 8 so as to cross the first heat exchanger 61, thereby recondensing the gas circulating in the return line 60.

[0065] The second heat exchanger 62 is located upstream of the first heat exchanger 61 and performs heat exchange between the gas circulating in the return line and the gas from the supply circuit 3 at the outlet of the tank 2. Since the gas exiting the tank 2 is necessarily at a low temperature, this makes it possible to cool the gas circulating in the return line 60. Thus, the gas is first pre-cooled by passing through the second heat exchanger 62 and then re-condensed by passing through the first heat exchanger 61. At the outlet of the first heat exchanger 61, the re-condensed gas reaches the circuit 8 for liquid gas and then reaches the tank 2 either through the outlet opening 21 or by being sprayed by the spray member 20.

[0066] Figures 6, 7, and 8 illustrate a second embodiment of the supply and cooling system 1 in three different operating modes. For each of these operating modes, two devices satisfy the supply requirements to the gas consumption device and / or the supply requirements to the cooling circuit 4. Solid lines indicate piping through which the fluid circulates, while dotted lines indicate piping through which the fluid does not circulate.

[0067] Therefore, Figure 6 shows the first operating mode of the supply and cooling system 1. In this first operating mode, the first compressor 11 is connected to the supply circuit 3 and supplies fluid to the gas consumption device, and the second compressor 12 is connected to the cooling circuit 4 and supplies fluid to the cooling circuit 4. Thus, the compression stages of the first compressor 11 are arranged in series as shown in Figure 3, while the compression stages of the second compressor 12 are arranged in parallel as shown in Figure 4. The fifth valve 45 and the sixth valve 46 are closed, isolating the supply circuit 3 and the first compressor 11 from the cooling circuit 4 and the second compressor 12.

[0068] Figure 7 shows a second operating mode of the supply and cooling system 1. In this second operating mode, the first compressor 11 and the second compressor 12 are connected to the supply circuit 3 to supply fluid to the gas consumption device. Thus, the compression stages of the first compressor 11 and the compression stages of the second compressor 12 are both arranged in series, as shown in Figure 3. The fifth valve 45 and the sixth valve 46 are opened to connect the second compressor 12 to the supply circuit 3, and the third valve 43 and the fourth valve 44 are closed to isolate the cooling circuit 4 from the rest of the supply and cooling system 1.

[0069] The liquid gas circulating in the circuit 8 for liquid gas is not cooled because the cooling circuit 4 is not operating. However, the liquid gas may circulate in the circuit 8 for liquid gas, and the gas that may circulate in the return line 60 may condense.

[0070] Figure 8 shows a third operating mode of the supply and cooling system 1. In this second operating mode, the first compressor 11 and the second compressor 12 are connected to the cooling circuit 4 and supply fluid to the cooling circuit 4. Thus, the compression stages of the first compressor 11 and the compression stages of the second compressor 12 are both arranged in parallel, as shown in Figure 4. The fifth valve 45 and the sixth valve 46 are opened to connect the first compressor 11 to the cooling circuit 4, and the first valve 41 and the second valve 42 are closed to isolate the supply circuit 3 from the rest of the supply and cooling system 1.

[0071] Since the supply circuit 3 is not operating, no gas evaporating in tank 2 is drawn in, and therefore, there is no excess gas circulating in the return line 60. Thus, the means for managing the internal pressure of tank 2 is to use the circuit 8 for the gas in liquid state, which is cooled by the cooling circuit 4, and then the cooled gas in liquid state is returned to tank 2 through the spray member 20 or the outlet opening 21.

[0072] Figure 9 shows a third embodiment of the supply and cooling system 1. This third embodiment does not include the circuit for the liquid gas described above, nor the return line of the second embodiment.

[0073] The difference in this third embodiment lies in the location of the heat exchanger 17, which is at least partially located directly within the tank 2. Thus, the heat exchanger 17 is directly involved in managing the tank pressure, rather than indirectly by cooling the circuit for the liquid gas, as in the previous embodiment.

[0074] Therefore, the heat exchanger 17 has only one path through which the refrigerant passes. The path may consist of a spiral tube, resulting in a longer refrigerant path within the heat exchanger 17. Thus, the heat exchanger 17 cools the headspace 200 of the tank 2. Consequently, the gas evaporated in the headspace 200 of the tank 2 condenses near the heat exchanger 17 and falls back into the tank 2. Thus, the heat exchanger 17 acts here as a gravity condenser.

[0075] The operation of the two compressors, supply circuit 3, and cooling circuit 4 is the same as that described in Figure 5.

[0076] Naturally, the present invention is not limited to the embodiments described so far, and many modifications can be made to these embodiments without departing from the scope of the invention.

[0077] The described invention clearly achieves its set objectives and makes it possible to propose a supply and cooling system for floating structures comprising at least one compressor capable of meeting various needs depending on the connection of the compression stages of the compressors. Modifications not described herein can be realized without departing from the context of the invention, insofar as they involve the supply and cooling system according to the present invention.

Claims

1. A gas supply and cooling system (1) for a floating structure comprising at least one tank (2) configured to contain gas, - At least one supply circuit (3) intended for the passage of gas arriving from the tank (2), comprising at least one compressor (10), wherein the supply circuit (3) is configured to connect the compressor (10) to the headspace (200) of the tank (2) and to supply gas to at least one gas consumption device (5, 6) installed on the floating structure, - A cooling circuit (4) intended for the passage of a refrigerant, comprising at least one heat exchanger (17) configured to be involved in managing the internal pressure of the tank (2), an internal heat exchanger (18), and a turbo compressor (13) comprising a compression member (14) located upstream of a first path of the internal heat exchanger (18) and a turbine (15) located downstream of the first path of the internal heat exchanger (18), wherein the compression member (14) and the turbine (15) are rotatably connected by a shaft (16), and the cooling circuit (4) is connected to the supply circuit (3) on both sides of the compressor (10). In a supply and cooling system (1) comprising, The compression device (10) comprises at least two compression stages (30, 31), and the supply and cooling system (1) comprises a control device (9) configured to connect the compression stages (30, 31) in series when the compression device (10) supplies fluid to the gas consumption devices (5, 6), and to connect the compression stages (30, 31) in parallel when the compression device (10) supplies fluid to the cooling circuit (4).

2. The supply and cooling system (1) according to claim 1, wherein the control device (9) comprises a main line (32) passing through each of the compression stages (30, 31) of the compression device (10).

3. The control device (9) comprises at least one peripheral line (33, 34) connected to the main line (32), and at least one valve (36, 37) for controlling the flow circulating through the peripheral line (33, 34), wherein the peripheral line (33, 34) bypasses the compression stage (30, 31), the supply and cooling system (1) according to claim 2.

4. The supply and cooling system (1) according to any one of claims 1 to 3, wherein the internal heat exchanger (18) comprises a first path and a second path that exchange heat with each other, the first path being located upstream of the heat exchanger (17), and the second path being located downstream of the heat exchanger (17).

5. The supply and cooling system (1) according to any one of claims 1 to 4, wherein the compression device (10) of the supply circuit (3) is a first compression device (11), and the supply and cooling system (1) comprises a second compression device (12) installed in parallel with the first compression device (11).

6. The supply and cooling system (1) according to claim 5, wherein the second compressor (12) comprises at least two compression stages (30, 31), and the control device (9) is configured to connect the compression stages (30, 31) of the second compressor (12) in series when the second compressor (12) supplies fluid to the gas consumption devices (5, 6), and to connect the compression stages (30, 31) of the second compressor (12) in parallel when the second compressor (12) supplies fluid to the cooling circuit (4).

7. A supply and cooling system (1) according to any one of claims 1 to 6, comprising a circuit for liquid gas (8) intended to allow liquid gas arriving from the tank (2) to pass through and configured to take in the liquid gas contained in the tank (2), wherein the heat exchanger (17) performs heat exchange between the liquid gas in the circuit for liquid gas (8) and a refrigerant circulating in the cooling circuit (4).

8. The supply and cooling system (1) according to claim 7, wherein the circuit (8) for the liquid gas comprises a member (20) for spraying the liquid gas into the headspace (200) of the tank, and an outlet opening (21) located in the lower part of the tank (2).

9. The supply and cooling system (1) according to claim 7 or 8, comprising a return line (60) connected to the supply circuit (3) downstream of the compressors (10, 11, 12) and extending to the circuit (8) for the liquid gas, wherein the supply and cooling system (1) comprises a first heat exchanger (61) that performs heat exchange between the gas circulating in the return line (60) and the gas circulating in the circuit (8) for the liquid gas.

10. The supply and cooling system (1) according to claim 9, further comprising a second heat exchanger (62) that performs heat exchange between the gas circulating in the supply circuit (3) upstream of the compression devices (10, 11, 12) and the gas circulating in the return line (60) upstream of the first heat exchanger (61).

11. The supply and cooling system (1) according to any one of claims 1 to 6, wherein the heat exchanger (17) is at least partially located in the headspace (200) of the tank (2).

12. A method for managing a gas contained in a tank (2), which is realized by a supply and cooling system (1) according to any one of claims 1 to 11, - A first step of determining the need to supply gas to the gas consumption devices (5, 6) or the need to manage the pressure inside the tank (2), - A second step in which the control device (9) connects the compression stages (30, 31) of the compression device (10) in series or in parallel, depending on the determined need. Methods that include...

13. In the management method, according to the first operating mode, the first compressor (11) has its compression stages (30, 31) connected in series and supplies fluid to the gas consumption devices (5, 6), while the second compressor (12) has its compression stages (30, 31) connected in parallel and supplies fluid to the cooling circuit (4), as described in claim 12, referencing claim 5.

14. The management method according to claim 13, wherein, according to the second operating mode of the management method, the first compressor (11) and the second compressor (12) have their compression stages (30, 31) connected in series to supply fluid to the gas consumption devices (5, 6).

15. The management method according to claim 14, wherein, according to the third operating mode of the management method, the first compressor (11) and the second compressor (12) have their compression stages (30, 31) connected in parallel to each other and supply fluid to the cooling circuit (4).

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