Supply and Cooling System for Floating Structures

Abstract

The present invention relates to a supply and cooling system (1) comprising: - a supply circuit (5); - a return line (7); - a first heat exchanger (8) configured to perform heat exchange between a gas circulating in the supply circuit (5) and a gas circulating in the return line (7); - a cooling loop (9) comprising an internal heat exchanger (15) configured to perform heat exchange between a refrigerant circulating in a first path (16) and a refrigerant circulating in a second path (17). In the supply and cooling system (1), the supply circuit (5) comprises a first branch (21) and a second branch (22), the first branch (21) passes through the first heat exchanger (8), and the internal heat exchanger (15) comprises at least a third path (23) forming the second branch (22). The present invention relates to a supply and cooling system (1).

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 in such a floating structure.

Background Art

[0002] During the navigation of a floating structure equipped with a tank for a gas in a liquid state intended to be delivered to a destination, the vessel can use at least a part of the gas in the liquid state and supply it to at least one of the engines of the vessel via a gas supply system. At the same time, it is necessary to maintain the pressure in the tank at an acceptable level, particularly by keeping the gas load in the liquid state at an appropriate temperature. For this purpose, the floating structure may also be provided with cooling means for directly or indirectly reliquefying the gas in the vapor state formed in the tank.

[0003] Thus, it is well known to draw in the gas evaporated using a supply circuit, compress it, and supply it to the engine. Alternatively or in parallel, the pressure in the tank can be reduced by combining cooling means and a cooling loop that circulates a refrigerant to reliquefy a part of the gas evaporated in the tank.

[0004] The above-described cooling loop configuration can be composed of a so-called turbo-Brayton cycle corresponding to a Brayton cycle equipped with a turbocharger. Thus, the cooling loop circulates a refrigerant that helps cool the gas.

[0005] Although it is efficient to use a turbo-Brayton cycle as a cooling loop in a system for supplying and cooling the gas contained in a tank, it has been found that it is not as efficient as some other equipment.

Summary of the Invention

Means for Solving the Problems

[0006] The present invention is a gas supply and cooling system for a floating structure comprising at least one tank configured to contain a gas, - at least a supply circuit comprising at least a first compression device, the at least supply circuit being configured to connect the tank to at least one gas-consuming device installed on the floating structure, - at least a return pipeline connected to the supply circuit downstream of the first compression device and extending to the tank, - at least a first heat exchanger configured to perform heat exchange between the gaseous gas circulating in the supply circuit upstream of the first compression device and the gaseous gas circulating in the return pipeline, - at least one cooling loop intended for the refrigerant to pass through, the at least one cooling loop comprising at least a second compression device, a heat exchanger configured to be involved in the management of the saturation pressure of the tank, an internal heat exchanger configured to perform heat exchange between the refrigerant circulating in at least a first path arranged upstream of the heat exchanger and the refrigerant circulating in at least a second path arranged downstream of the heat exchanger, and a turbocharger comprising a compression member arranged between the second compression device and the first path of the internal heat exchanger and a turbine arranged between the first path of the internal heat exchanger and the heat exchanger, the compression member and the turbine being rotatably connected by a shaft, in a supply and cooling system comprising, the supply circuit comprises a branch point, a confluence point, and at least a first branch path and a second branch path starting from the branch point and ending at the confluence point, the first branch path passing through the first heat exchanger, and the internal heat exchanger of the cooling loop comprising at least a third path constituting the second branch path, and by proposing a supply and cooling system characterized in this way, it is possible to implement the cycle as described above and improve its cooling performance.

[0007] With the supply and cooling system according to the present invention, the gaseous gas in the vapor state exiting the tank can be effectively utilized by circulating it through the internal heat exchanger of the cooling loop. Due to the resulting heat exchange, the performance of the cooling loop is improved, and thus the overall cooling efficiency and re-liquefaction efficiency of the supply and cooling system are improved.

[0008] The supply circuit can draw in the gaseous gas in the vapor state formed in the headspace of the tank. The gaseous gas in the vapor state is formed naturally over time or is forced to form by a floating structure. In order to adjust the saturation pressure of the tank, the gaseous gas in the vapor state needs to be discharged or re-liquefied. Therefore, the supply circuit ensures the circulation of the gaseous gas in the vapor state, and as a result, the gas can be supplied to the gas-consuming equipment. The gas-consuming equipment can be, for example, an engine for propelling the floating structure or a generator for supplying power to the floating structure. If the gas is compressed to an appropriate pressure, the gaseous gas in the vapor state can be supplied to the gas-consuming equipment. In this way, the first compression device can compress the gas to a pressure that meets the requirements of the gas-consuming equipment.

[0009] When there is no need to supply the gas-consuming equipment or when only a part of the gaseous gas in the vapor state contained in the tank needs to be consumed, the compressed excess gas in the vapor state can be circulated through the return pipeline and re-liquefied. The first heat exchanger pre-cools the gaseous gas in the vapor state circulating through the return pipeline, and thereby the heat quantity thereof is transferred to the gaseous gas in the vapor state exiting the tank. Such pre-cooling facilitates the subsequent re-liquefaction of the gas circulating through the return pipeline.

[0010] The cooling loop is a turbo-Brayton type loop, i.e., a Brayton cycle equipped with a turbocharger. The refrigerant circulating in the cooling loop is, for example, nitrogen and is circulated by a second compression device. The compression member and the turbine of the turbocharger are rotationally driven together by their mechanical connection. The turbine is rotationally driven, and thus rotates the shaft, which in turn rotates the compression member. Therefore, the refrigerant is first compressed by the compression member. Next, the refrigerant passes through a first path to an internal heat exchanger, and the refrigerant expands by passing through the turbine.

[0011] Next, the refrigerant passes through a heat exchanger. In particular, this heat exchange makes it possible to manage the saturation pressure of the tank thereafter. Next, the refrigerant passes through the internal heat exchanger again, but this time via a second path. Therefore, in the internal heat exchanger, heat exchange is performed between the refrigerant circulating in the first path at high pressure and the refrigerant circulating in the second path at low pressure. This heat exchange ensures the thermodynamic control of the cooling loop. After exiting the second path of the internal heat exchanger, the refrigerant is compressed again by the second compression device.

[0012] By a branch point, the supply circuit is divided into a first branch path and a second branch path. Using the first branch path, the gaseous state gas is circulated in the aforementioned first heat exchanger. The second branch path is arranged in parallel with the first branch path and thus circulates the gas so that the gas bypasses the first heat exchanger.

[0013] Using the second branch path, the gaseous state gas circulates, and as a result, the gas passes through the internal heat exchanger via the third path. Therefore, the gaseous state gas exiting the tank can participate in the heat exchange taking place within the internal heat exchanger, and by extension, can participate in the heat control of the cooling loop. Therefore, with the supply and cooling system of the present invention, it is possible to utilize the low temperature of the gaseous state gas at the tank outlet to further cool the refrigerant circulating in the first path of the internal heat exchanger, and by extension, to improve subsequent expansion, which helps to improve the heat exchange taking place in the heat exchanger. Therefore, the cooling performance of the cooling loop is improved.

[0014] According to one feature of the present invention, the supply circuit comprises a third branch path arranged in parallel with respect to the first and second branch paths. Therefore, this third branch path merges directly into the first compressor without heat exchange. The circulation via the third branch path bypasses the first heat exchanger and the internal heat exchanger.

[0015] According to one feature of the present invention, the supply and cooling system comprises a cooling circuit including at least one pump configured to draw out the gaseous state gas from the tank, and the heat exchanger is configured to effect heat exchange between the refrigerant circulating in the cooling loop and the gaseous state gas circulating in the cooling circuit. The pump of the cooling circuit can be submerged, for example, at the bottom of the tank to draw out the gaseous state gas.

[0016] The heat exchanger subcools the gaseous state gas by effecting heat exchange with the refrigerant of the cooling loop. Therefore, the subcooled gaseous state gas can, for example, help manage the saturation pressure of the tank by re-liquefying the gaseous state gas.

[0017] According to one feature of the present invention, the supply and cooling system comprises a second heat exchanger configured to effect heat exchange between the gas in liquid state circulating in the cooling circuit downstream of the heat exchanger and the gas in vapor state circulating in the return line downstream of the first heat exchanger. In other words, the heat exchange effected by the second heat exchanger enables the re-liquefaction of the gas in vapor state circulating in the return line. The gas in vapor state circulating in the return line is pre-cooled in advance by the first heat exchanger, while the gas in liquid state circulating in the cooling circuit is pre-sub-cooled in advance by passing through the heat exchanger. Therefore, the sub-cooled gas enables the temperature of the gas in vapor state to be reduced to the re-liquefaction point of the gas.

[0018] According to one feature of the present invention, the cooling circuit is connected to the return line downstream of the second heat exchanger, and the return line comprises at least one end opening into the tank. Therefore, the re-liquefied gas and the gas in liquid state merge and circulate together up to the end opening into the tank.

[0019] According to one feature of the present invention, the end is a spray member and / or an orifice arranged in the lower part of the tank. The orifice provides a return flow to the tank and reduces the overall temperature of the gas in liquid state in the tank. The spray member sprays the gas in liquid state into the headspace of the tank, thereby promoting the condensation of the gas in vapor state present in the headspace of the tank and reducing the saturation pressure of the tank.

[0020] According to one feature of the present invention, the supply and cooling system comprises a cooling path and a spraying device. The cooling path is connected to a cooling circuit and extends to the spraying device. The spraying device is configured to evaporate the gaseous state of the liquid in the second branch upstream of the third path of the internal heat exchanger. The cooling path is derived from the cooling circuit and thus enables the circulation of the gaseous state of the liquid generated from the tank. The spraying device is arranged in the second branch and evaporates the gaseous state of the liquid in the second branch through which the gaseous state of the gas circulates. The gaseous state of the liquid is converted into the gaseous state by reducing the temperature of the gaseous state of the gas circulating in the second branch before passing through the third path and going to the internal heat exchanger.

[0021] Therefore, the cooling path and the spraying device ensure the cooling of the gaseous state of the gas generated from the tank, and the temperature of this gas varies greatly. Such cooling is essential. Because if the gaseous state of the gas circulates through the third path at an excessively high temperature, it may adversely affect the operation of the internal heat exchanger that can only tolerate a maximum temperature difference of 28°C between the fluids circulating in two adjacent paths. Therefore, the cooling path and the spraying device adjust the temperature of the gas circulating through the second branch, and any malfunction of the internal heat exchanger due to an excessively high temperature difference between the fluids circulating through the internal heat exchanger is avoided.

[0022] According to one feature of the present invention, the supply and cooling system comprises a detecting means for detecting the temperature of the gas circulating in the second branch between the spraying device and the third path of the internal heat exchanger. The detecting means may be, for example, a temperature sensor and is arranged to measure the temperature of the gaseous state of the gas circulating through the second branch before the gaseous state of the gas circulating in the second branch enters the internal heat exchanger through the third path. This temperature check prevents the proper operation of the internal heat exchanger from being impaired due to the excessively high temperature of the gaseous state of the gas as described above.

[0023] According to one feature of the present invention, the cooling path is provided with a flow control valve, and the supply and cooling system includes a control module configured to control the flow control valve based on the temperature recorded by the detection means. The flow control valve enables the increase or decrease of the gas in the liquid state circulated to the spraying device. The greater the flow rate of the gas in the liquid state, the stronger the cooling of the gas in the vapor state, and vice versa. Therefore, according to the temperature of the gas in the vapor state recorded by the detection means upstream of the third path, the control module modifies the flow control member, thereby obtaining the temperature of the gas in the vapor state that is adapted to the internal heat exchanger and the refrigerant circulating therein.

[0024] According to one feature of the present invention, the supply and cooling system includes an auxiliary supply path connected to the cooling circuit and configured to supply gas to the gas-consuming equipment, and the internal heat exchanger includes a fourth path constituting the auxiliary supply path. Such a configuration can be implemented when there is not enough gas in the vapor state formed in the head space of the tank and the floating structure does not have means to forcibly evaporate the gas in the liquid state contained in the tank. To compensate for the shortage of the gas in the vapor state, supply can be made to the gas-consuming equipment via the auxiliary supply path, and the internal heat exchanger functions as an evaporator for the gas in the liquid state intended to be consumed by the gas-consuming equipment.

[0025] The gas in the liquid state is drawn in by the pump of the cooling circuit and circulates through the auxiliary supply pipeline. The gas in the liquid state is converted into the vapor state by passing through the fourth path of the internal heat exchanger and is then supplied to the gas-consuming equipment. Based on the required pressure of the gas in the vapor state, the auxiliary supply pipeline can be connected to the supply circuit upstream or downstream of the first compression device.

[0026] According to one feature of the present invention, the heat exchange length of the third path of the internal heat exchanger is shorter than the heat exchange length of either one of the first path and the second path. In other words, the internal heat exchanger includes, for example, a first end provided with an inlet of the first path and, for example, a second end provided with an outlet of the first path, and the inlet of the third path is disposed between the first end and the second end. As described above, the temperature of the gaseous state gas exiting the tank may vary, and the internal heat exchanger may not allow the temperature difference between the fluids circulating between two adjacent paths to be excessively large.

[0027] The inlet of the third path is arranged such that the temperature of the refrigerant circulating in the second path is substantially equal to the nominal temperature of the gaseous state gas exiting the tank. Thus, this inlet of the third path is positioned at a level of the internal heat exchanger where the refrigerant circulating in the second path of the internal heat exchanger has the amount of heat already accumulated by heat exchange with the refrigerant circulating in the first path of the internal heat exchanger. In this configuration, even when the gaseous state gas circulating in the third path enters the internal heat exchanger at a temperature higher or lower than the nominal temperature of the gaseous state gas exiting the tank, the temperature difference between the gaseous state gas circulating in the third path and the refrigerant circulating in the second path remains limited, and there is no risk of damaging the internal heat exchanger. Such a configuration enables the use of more affordable heat exchanger technology.

[0028] The present invention is also directed to a method for managing a gas contained in at least one tank of a floating structure, which is implemented by the aforementioned supply and cooling system, and during the management, - when the speed of the floating structure is less than a specified speed threshold, circulating the gaseous state gas generated from the tank through a first branch path, - when the speed of the floating structure is greater than the speed threshold, circulating the gaseous state gas generated from the tank through a second branch path. The method is also targeted.

[0029] The speed threshold of the floating structure may correspond to a speed of, for example, 12 knots or 15 knots. When the speed of the floating structure is less than the speed threshold, the floating structure is considered to be moving at a low speed or zero speed. Therefore, if the gas consumption device is an engine that propels the floating structure, it hardly consumes gaseous gas in a vapor state. Therefore, the gaseous gas in a vapor state preferentially circulates in the first branch path, and as a result, heat exchange in the first heat exchanger can be performed, and precooling of the gaseous gas in a vapor state circulating in the return pipeline can be ensured.

[0030] When the speed of the floating structure is greater than the speed threshold, the floating structure is considered to be moving at a medium speed or a high speed. In this situation, the gaseous gas in a vapor state preferentially circulates through the second branch path and thus the third path of the internal heat exchanger to enhance the cooling capacity of the cooling loop. In order to switch the circulation of the gaseous gas in a vapor state from one branch path to another branch path, the supply and cooling system can include a series of valves that can be opened and closed based on the measured speed of the floating structure.

[0031] According to the features of this method, the gaseous gas in a vapor state generated from the tank circulates through the third branch path when the gas is not circulating through the first branch path and / or the second branch path. Circulation in the third branch path can be useful, for example, during the startup phase of the floating structure when the temperature of the gaseous gas in a vapor state is not suitable for circulating the gas through the internal heat exchanger and it is not worth passing through the first heat exchanger. Circulation of the gaseous gas in a vapor state through the third branch path can also be used, for example, when the cooling loop is not operating.

[0032] Other features and advantages of the present invention will become apparent from both of several exemplary embodiments provided for illustrative purposes only and without limitation, with reference to the following description and the accompanying schematic diagrams.

Brief Description of the Drawings

[0033]

Figure 1

Figure 2

Figure 3

Figure 4

[0034] FIG. 1 shows a first embodiment of a supply and cooling system 1. The supply and cooling system 1 can be integrated into a floating structure specialized for the transport and / or storage of gases in a liquid state, and the floating structure comprises at least one tank 2 containing a gas in a liquid state.

[0035] Accordingly, the supply and cooling system 1 is configured to interact with the tank 2, in particular to adjust the saturation pressure of the tank 2. The gas in a liquid state contained in the tank 2 may partially evaporate in the headspace 3 of the tank 2 to form a gas in a vapor state. Such evaporation can occur naturally or forcibly. The gas in a vapor state formed in the headspace 3 contributes to an increase in the saturation pressure of the tank, and therefore, in order to limit such a pressure increase, it is necessary to be discharged or re-liquefied.

[0036] In order to manage the saturation pressure of the tank 2, the supply and cooling system 1 can process this gas and supply it to at least one gas-consuming device 4. In FIG. 1, the supply and cooling system 1 is configured to supply two gas-consuming devices 4. By way of example, the floating structure can comprise a high-pressure gas-consuming device 4, which may be an engine that provides propulsion to the floating structure, and a low-pressure gas-consuming device 4, which may be a generator that supplies power to the floating structure.

[0037] To ensure the supply to the gas-consuming device 4, the supply and cooling system 1 comprises a supply circuit 5 extending between the tank 2 and the gas-consuming device 4. The supply circuit 5 comprises a first compression device 6 for drawing in and compressing the gaseous gas contained in the headspace 3 of the tank 2. The gaseous gas can then circulate to the gas-consuming device 4 and be supplied to the gas-consuming device 4. Depending on the nature of the gas-consuming device 4, the supply and cooling system 1 can comprise additional compressors (not shown) to increase the pressure of the gaseous gas, so that the gaseous gas reaches a pressure suitable for supply to the gas-consuming device 4.

[0038] The supply and cooling system 1 also comprises a return line 7 connected to the supply circuit 5, more specifically downstream of the first compression device 6. Thus, the return line 7 extends from the supply circuit 5 to the tank 2. The return line 7 enables the recirculation of the gaseous gas not used for the supply to the gas-consuming device 4 when it is not necessary to supply the gaseous gas to the gas-consuming device 4 or when there is more gaseous gas present than is required for the supply to the gas-consuming device 4.

[0039] The gaseous gas circulating in the return line 7 is re-liquefied to reduce the saturation pressure of the tank, while intending to avoid the removal of said gaseous gas not used for the supply to the gas-consuming device 4. To do this, the supply and cooling system 1 comprises a first heat exchanger 8 configured to effect a heat exchange between the gaseous compressed gas circulating in the return line 7 and the gaseous gas in liquid state circulating in the supply circuit 5 upstream of the first compression device 6.

[0040] Thus, the first heat exchanger 8 precools the gaseous gas circulating in the return line 7 using the gaseous gas exiting the tank 2, which is at a lower temperature than the gaseous gas circulating in the return line 7. Such precooling helps to facilitate the subsequent re-liquefaction of the gaseous gas.

[0041] The supply and cooling system 1 also includes a cooling loop 9 corresponding to the closed circuit through which the refrigerant circulates in FIG. 1. The refrigerant circulates through the cooling loop 9 in a gaseous state and may be, for example, nitrogen. More specifically, the cooling loop 9 is a Brayton cycle including a turbocharger 10.

[0042] The cooling loop 9 includes a second compression device 11 for circulating the refrigerant within the cooling loop 9. The turbocharger 10 includes a compression member 12 and a turbine 13 connected by a shaft 14. The turbine 13 is rotationally driven to drive the shaft 14, and the shaft 14 drives the compression member 12. The cooling loop 9 also includes an internal heat exchanger 15 having a first path 16 and a second path 17. The refrigerant circulating through the cooling loop 9 also passes through a heat exchanger 18.

[0043] Therefore, following the path of the refrigerant within the cooling loop 9, the refrigerant is first compressed by the second compression device 11 and then further compressed by the compression member 12 of the turbocharger 10. The high-pressure refrigerant then circulates through the first path 16 and subsequently expands within the turbine 13. After expansion, the low-pressure refrigerant flows through the heat exchanger 18 and then circulates through the second path 17 of the internal heat exchanger 15. Therefore, in the internal heat exchanger 15, heat exchange occurs between the refrigerant circulating at high pressure through the first path 16 and the refrigerant circulating at low pressure through the second path 17. The refrigerant is compressed again by the second compression device 11 at the outlet of the second path 17.

[0044] The cooling loop 9 described so far makes it possible to achieve an efficient cooling capacity, but such a cooling loop 9 has been found not to be as efficient in terms of cooling capacity as another loop with a structurally different configuration.

[0045] To improve the capacity of the cooling loop 9, the supply circuit 5 includes a branch point 19 and a confluence point 20 located downstream of the branch point 19. The branch point 19 and the confluence point 20 are arranged on both sides of the first heat exchanger 8, and the supply circuit 5 includes a first branch path 21 and a second branch path 22 extending between the branch point 19 and the confluence point 20.

[0046] The first branch path 21 enables the vaporous gas generated from the tank 2 to pass through the first heat exchanger 8. The second branch path 22 is configured to bypass the first heat exchanger 8 and circulate the vaporous gas within the internal heat exchanger 15. The internal heat exchanger 15 includes a third path 23 that enables the vaporous gas circulating in the second branch path 22 to circulate within the internal heat exchanger 15.

[0047] With the second branch path 22 and the third path 23, the refrigerant circulating in the first path 16 can be further cooled using the vaporous gas exiting the tank 2, thereby facilitating the subsequent expansion of the refrigerant by the turbine 13. When the refrigerant expands more easily, the cooling capacity is improved, thereby enhancing the overall efficiency of the cooling loop 9. Another advantage of such a configuration is that the vaporous gas circulating in the third path 23 can absorb heat without any subsequent undesirable results.

[0048] The vaporous gas circulating in the supply circuit 5 can circulate through the first branch path 21 or the second branch path 22, and the selection of the first branch path 21 or the second branch path 22 is optimized based on the speed of the floating structure.

[0049] Therefore, when the speed of the floating structure is below a predetermined speed threshold, for example, less than 12 knots or 15 knots, the floating structure is moving at a low speed or zero speed. Therefore, at least one of the gas-consuming devices 4, more specifically, the device used to propel the floating structure, consumes little or no vaporous gas. Therefore, the vaporous gas preferentially circulates through the first branch path 21, and as a result, heat exchange occurs in the first heat exchanger 8, ensuring pre-cooling of the vaporous gas circulating through the return pipeline 7.

[0050] When the speed of the floating structure is greater than the speed threshold, the floating structure is moving at medium or high speed. In this situation, the gaseous state gas preferentially passes through the second branch path 22 and then circulates through the third path 23 of the internal heat exchanger 15, thereby enhancing the cooling capacity of the cooling loop 9.

[0051] The supply circuit 5 also includes a third branch path 24 installed in parallel with the first branch path 21 and the second branch path 22. Therefore, the third branch path 24 enables the gaseous state gas circulating in the supply circuit 5 to bypass the first heat exchanger 8 and the internal heat exchanger 15. Circulating the gaseous state gas through the third branch path 24 is advantageous when the temperature of the gaseous state gas is not sufficient to circulate through the internal heat exchanger 15 and when it is not worthwhile to circulate the gaseous state gas through the first heat exchanger 8. Circulating the gaseous state gas through the third branch path 27 can also be utilized, for example, when the cooling loop 9 is under maintenance or not operating.

[0052] To select through which branch path the gaseous state gas circulates, the first branch path 21 is provided with a first valve 25, the second branch path 22 is provided with a second valve 26, and the third branch path 24 is provided with a third valve 27.

[0053] Each of these three valves 25, 26, 27 can be opened and closed according to the branch paths 21, 22, 24 through which the gaseous state gas needs to circulate in order to maximize the performance of the supply and cooling system 1. The valves 25, 26, 27 are controlled based on the speed of the floating structure and whether one of the aforementioned situations causes the gaseous state gas to circulate through the third branch path 27.

[0054] The supply system 1 also includes a cooling circuit 28 configured to circulate the gaseous state gas generated from the tank 2. The cooling circuit 28 includes a pump 29 for drawing out the gaseous state gas contained in the tank 2.

[0055] The gas in the liquid state circulates through the cooling circuit 28 and passes through the heat exchanger 18. Thus, from the above, it is understood that the heat exchanger 18 is configured to perform heat exchange between the gas in the liquid state circulating through the cooling circuit 28 and the refrigerant circulating through the cooling loop 9. Thus, the refrigerant subcools the gas in the liquid state passing through the heat exchanger 18. Thus, circulating the gas in the vapor state through the third path 23 of the internal heat exchanger 15 to improve the performance of the cooling loop 9 enables the gas in the liquid state in the heat exchanger 18 to be more efficiently subcooled.

[0056] When exiting the heat exchanger, the subcooled gas in the liquid state continues to circulate through the cooling circuit 28 until it passes through the second heat exchanger 30. The second heat exchanger 30 is configured to perform heat exchange between the vapor state gas circulating through the return line 7 when the vapor state gas circulating through the supply circuit 5 circulates through the first branch path 21 and the vapor state gas pre-cooled after passing through the first heat exchanger 8 and the subcooled gas in the liquid state that has been pre-subcooled after passing through the heat exchanger 18. Thus, the vapor state gas circulating through the return line 7 is re-liquefied within this second heat exchanger 30, and the subcooled gas in the liquid state is at a sufficiently low temperature to guarantee such re-liquefaction.

[0057] The cooling circuit 28 continues after the outlet of the second heat exchanger 30 and then merges with the return line 7, and the confluence point of the cooling circuit 28 and the return line 7 is downstream of the second heat exchanger 30, respectively. Such a connection enables the gas in the liquid state circulating through the cooling circuit 28 to be mixed with the re-liquefied gas circulating through the return line 7.

[0058] Therefore, downstream of the second heat exchanger 30 and downstream of the connection of the cooling circuit 28, the return line 7 extends to the tank 2 and comprises at least one end 31 opening into said tank 2. The end 31 can be used to adjust the temperature of the gas contained in the tank 2 and / or the saturation pressure of said tank 2. Thus, the end 31 may be an orifice 32 or a spraying member 33. The orifice 32 may be arranged at the bottom side of the tank to ensure that the gas in the liquid state returns to a region of as low a temperature as possible. The spraying member 33 is located in the headspace 3 of the tank 2 and sprays the gas in the liquid state into the headspace 3 of the tank 2 to condense the gas in the vapor state present in the headspace 3 and reduce the saturation pressure of the tank 2. Thus, this shows how the cooling loop 9 indirectly helps to adjust the pressure and / or temperature of the gas in the liquid state contained in the tank 2.

[0059] Figure 2 shows a second embodiment of the supply and cooling system 1 according to the invention. The second embodiment differs from the first embodiment in that the supply and cooling system 1 particularly comprises a cooling path 34 and a spraying device 35.

[0060] The cooling path 34 is connected to the cooling circuit 28 downstream of the pump 29. Thus, the gas in the liquid state circulates through the cooling path 34. The cooling path 34 extends to a spraying device 35 arranged in the second branch path 22, which evaporates the gas in the liquid state circulating through the cooling path 34 in the second branch path.

[0061] The purpose of such an operation is to lower the temperature of the gas in the vapor state when the temperature of the gas in the vapor state circulating through the second branch path 22 is excessively high. This cooling is carried out before the gas in the vapor state circulates through the third path 23 in the internal heat exchanger 15. In fact, if the temperature of the gas in the vapor state is excessively high, there is a risk of damaging the internal heat exchanger 15, which allows only a limited temperature difference between the two fluids circulating through two adjacent paths. Thus, the cooling of the gas in the vapor state may be essential to maintain the proper operation of the internal heat exchanger 15.

[0062] To accurately adjust the temperature of the gaseous state gas circulating through the second branch path 22, the supply and cooling system 1 includes detection means 36. The detection means 36 can measure the temperature of the gaseous state gas circulating in the second branch path 22 between the spraying device 35 and the third path 23. Therefore, the detection means 36 can be used to confirm whether the temperature of the gaseous state gas is appropriate for passing through the internal heat exchanger 15.

[0063] The second embodiment of the supply and cooling system 1 also includes a flow control valve 37 for controlling the flow rate of the gaseous state gas in the liquid state circulating through the cooling path 34. The greater the flow rate, the more gaseous state gas in the liquid state evaporates in the second branch path 22, and the lower the temperature of the gaseous state gas circulating in the second branch path 22.

[0064] The supply and cooling system 1 finally includes a control module 38 that can adjust the flow cross-section of the flow control member 37 to change the flow rate of the gaseous state gas in the liquid state circulating through the cooling path 34. The control module 38 communicates with the detection means 36. Therefore, according to the temperature detected by the detection means 36, the control module 38 changes the flow cross-section of the control member 37, thereby maintaining the gaseous state gas at an appropriate temperature before circulating through the third path 23 of the internal heat exchanger 15, thereby maintaining the service life and proper operation of the internal heat exchanger 15.

[0065] Except as described above, the second embodiment of the supply and cooling system 1 has the same structural and functional features as the first embodiment. Therefore, refer to the description of FIG. 1 for all features common to the two embodiments.

[0066] FIG. 3 is a diagram of a third embodiment of the supply and cooling system 1. This third embodiment is different from the above two embodiments in that it particularly includes an auxiliary supply path 39 that is connected to the cooling circuit 28 and extends to merge into the supply circuit 5 for participating in the supply to the gas-consuming device 4.

[0067] The auxiliary supply path 39 is used when there is no vaporous gas for supplying the gas consumption device 4 in the head space 3 of the tank 2. In this configuration, the pump 29 circulates the liquid-state gas through the auxiliary supply path 39.

[0068] The auxiliary supply path 39 passes through the internal heat exchanger 15. Therefore, the internal heat exchanger 15 is different from the previous embodiment in that it includes a fourth path 40 that constitutes the auxiliary supply path 39.

[0069] When the liquid-state gas passes through the internal heat exchanger 15 via the fourth path 40, the performance of the cooling loop 9 is improved by heat exchange with the refrigerant, similar to the previous embodiment. Also, by heat exchange, the evaporation of the liquid-state gas circulating in the fourth path 40 is surely performed. Therefore, the internal heat exchanger 15 functions as an evaporator for the liquid-state gas circulating in the auxiliary supply path 39.

[0070] At the outlet of the fourth path 40, the evaporated gas continues to circulate through the auxiliary supply path 39, and then merges into the supply circuit 5 and is supplied to the gas consumption device 4. In FIG. 3, the auxiliary supply path 39 is connected to the supply circuit 5 downstream of the first compression device 6. However, for example, according to the pressure requirements of the gas consumption device 4, it is also possible to connect the auxiliary supply path 39 to the supply circuit 5 upstream of the first compression device 6.

[0071] Except for the auxiliary supply path 39 and the fourth path 40, all the structural and functional features of the third embodiment of the supply and cooling system 1 are the same as those of the first embodiment. Refer to the description of FIG. 1 regarding the elements common to the two embodiments.

[0072] FIG. 4 shows the detailed structure of various paths of the internal heat exchanger 15 shown in FIGS. 1 and 2. As described above, if the temperature difference between two fluids circulating through two adjacent paths is too large, the internal heat exchanger 15 may be damaged. The problem related to the temperature of the gaseous state gas circulating through the third path 23 can be particularly solved by the second embodiment of the supply and cooling system according to the present invention.

[0073] With the configuration shown in FIG. 4, it is also possible to limit the temperature difference between the gaseous state gas circulating through the third path 23 and the refrigerant circulating through the second path 17.

[0074] The internal heat exchanger 15 includes, for example, a first end 41 and a second end 42 that define the main dimensions of the internal heat exchanger 15. The first path 16 and the second path 17 that form part of the cooling loop both extend between the first end 41 and the second end 42. Therefore, both the first path 16 and the second path 17 have a heat exchange length L1 that is the same as the distance between the first end 41 and the second end 42 of the internal heat exchanger 15. The temperature of the refrigerant circulating through the second path 17 increases as the refrigerant circulates through the path in the direction from the second end 42 to the first end 41.

[0075] A special feature of the internal heat exchanger 15 shown in FIG. 4 is that the inlet 43 of the third path 23 is positioned between the first end 41 and the second end 42, for example, on one of the walls parallel to the first path 16 and the second path 17, while the outlet 44 of the third path 23 is positioned at one of the ends 41, 42 of the internal heat exchanger, for example, the first end 41.

[0076] Therefore, the third path 23 has a heat exchange length L2 that is shorter than the heat exchange length L1 of the first path 16 or the heat exchange length L1 of the second path 17.

[0077] Due to this difference in length, the refrigerant circulating through the second path 17 first exchanges heat only with the refrigerant circulating through the first path 16 and its temperature rises. Therefore, the gaseous state gas enters the third path 23 through the inlet 43 at a temperature higher than the level at which the refrigerant circulating through the second path 17 previously absorbed heat, that is, higher than the inlet of the second path 17.

[0078] With such a configuration, it becomes possible for the refrigerant circulating through the second path 17 to reach a temperature equal to or substantially equal to the nominal temperature of the gaseous state gas at the outlet of the tank. Therefore, even if the gaseous state gas is at a temperature higher or lower than the nominal temperature, the risk of a large temperature difference occurring between the gaseous state gas circulating through the third path 23 and the refrigerant circulating through the second path 17 is significantly reduced.

[0079] Preferably, the temperature difference between two fluids circulating through two adjacent paths should not exceed 28°C. If this is likely to occur due to the temperature of the gaseous state gas being excessively high, the temperature can be reduced by the spraying device described in FIG. 2 in the supply and cooling system. In another case, the third path 23 of the internal heat exchanger 15 can be bypassed, for example, by circulating the gas through a third branch path. The structure of the internal heat exchanger 15 disclosed in FIG. 4 can be integrated into any of the previously disclosed embodiments.

[0080] Of course, the present invention is not limited to the examples described here, and numerous changes can be made to these examples without departing from the scope of the present invention.

[0081] The disclosed invention achieves the aforementioned object and enables the proposal of a supply and cooling system for a floating structure that improves the performance of a cooling loop integrated into the system by utilizing the low temperature of a gas in a liquid state stored in a tank. Variations not disclosed in this specification can be implemented without departing from the context of the invention as long as they constitute the supply and cooling system according to the invention in accordance with the 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 a supply circuit (5) comprising at least a first compression device (6), the at least supply circuit (5) being configured to connect the tank (2) to at least one gas-consuming device (4) equipped on the floating structure, - at least a return pipeline (7) connected to the supply circuit (5) downstream of the first compression device (6) and extending to the tank (2), - at least a first heat exchanger (8) configured to perform heat exchange between the gas in vapor state circulating in the supply circuit (5) upstream of the first compression device (6) and the gas in vapor state circulating in the return pipeline (7), - at least a cooling loop (9) intended for the refrigerant to pass through, comprising at least a second compression device (11), a heat exchanger (18) configured to be involved in the management of the saturation pressure of the tank (2), an internal heat exchanger (15) configured to perform heat exchange between the refrigerant circulating in at least a first path (16) arranged upstream of the heat exchanger (18) and the refrigerant circulating in at least a second path (17) arranged downstream of the heat exchanger (18), and a turbocharger (10) comprising a compression member (12) arranged between the second compression device (11) and the first path (16) of the internal heat exchanger (15), and a turbine (13) arranged between the first path (16) of the internal heat exchanger (15) and the heat exchanger (18), the compression member (12) and the turbine (13) being rotatably connected by a shaft (14), comprising a supply and cooling system (1), wherein the supply circuit (5) comprises a branch point (19), a confluence point (20), and at least a first branch (21) and a second branch (22) starting from the branch point (19) and ending at the confluence point (20), the first branch (21) passing through the first heat exchanger (8), and the internal heat exchanger (15) of the cooling loop (9) comprising at least a third path (23) constituting the second branch (22), characterized by a supply and cooling system (1).

2. The supply and cooling system (1) according to claim 1, wherein the supply circuit (5) comprises a third branch path (24) arranged in parallel with the first branch path (21) and the second branch path (22).

3. The supply and cooling system (1) according to claim 1 or 2, comprising a cooling circuit (28) including at least a pump (29) configured to draw the gas in a liquid state from the tank (2), wherein the heat exchanger (18) is configured to perform heat exchange between the refrigerant circulating in the cooling loop (9) and the gas in a liquid state circulating in the cooling circuit (28).

4. The supply and cooling system (1) according to claim 3, comprising a second heat exchanger (30) configured to perform heat exchange between the gas in a liquid state circulating in the cooling circuit (28) downstream of the heat exchanger (18) and the gas in a vapor state circulating in the return pipe line (7) downstream of the first heat exchanger (8).

5. The supply and cooling system (1) according to claim 4, wherein the cooling circuit (28) is connected to the return pipe line (7) downstream of the second heat exchanger (30), and the return pipe line comprises at least one end portion (31) opening into the tank (2).

6. The supply and cooling system (1) according to claim 5, wherein the end portion (31) is a spray member (33) and / or an orifice (32) arranged in the lower part of the tank (2).

7. The supply and cooling system (1) according to any one of claims 3 to 6, comprising a cooling path (34) and a spraying device (35), wherein the cooling path (34) is connected to the cooling circuit (28) and extends to the spraying device (35), and the spraying device (35) is configured to evaporate the gas in a liquid state in the second branch path (22) upstream of the third path (23) of the internal heat exchanger (15).

8. The supply and cooling system (1) according to claim 7, comprising a detecting means (36) for detecting the temperature of the gas circulating in the second branch path (22) between the spraying device (35) and the third path (23) of the internal heat exchanger (15).

9. The cooling path (34) comprises a flow control valve (37), and the supply and cooling system (1) comprises a control module (38) configured to control the flow control valve (37) based on the temperature recorded by the detection means (36). The supply and cooling system (1) according to claim 8.

10. Comprising an auxiliary supply path (39) connected to the cooling circuit (28) and configured to supply gas to the gas-consuming device (4), the internal heat exchanger (15) comprising a fourth path (40) constituting the auxiliary supply path (39). The supply and cooling system (1) according to any one of claims 3 to 9.

11. The heat exchange length (L2) of the third path (23) of the internal heat exchanger (15) is shorter than the heat exchange length (L1) of either one of the first path (16) and the second path (17). The supply and cooling system (1) according to any one of claims 1 to 10.

12. A method for managing gas contained in at least one tank (2) of a floating structure, implemented by the supply and cooling system (1) according to any one of claims 1 to 11, during management, - When the speed of the floating structure is less than a specified speed threshold, the gaseous gas generated from the tank (2) is circulated through the first branch path (21), - When the speed of the floating structure is greater than the speed threshold, the gaseous gas generated from the tank (2) is circulated through the second branch path (22). Method.

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