EP4062046A1

EP4062046A1 - System for supplying gas to at least one gas-consuming appliance equipping a ship

Info

Publication number: EP4062046A1
Application number: EP20823901.2A
Authority: EP
Inventors: Bernard Aoun; Romain NARME; Martin BUISSART
Original assignee: Gaztransport et Technigaz SA
Current assignee: Gaztransport et Technigaz SA
Priority date: 2019-11-20
Filing date: 2020-11-17
Publication date: 2022-09-28
Also published as: CN114729612A; US20230032594A1; JP2023502422A; FR3103227A1; KR20220100692A; WO2021099726A1; FR3103227B1

Abstract

The present invention relates to a system (100) for supplying gas to at least one gas-consuming appliance (300) equipping a ship (70), the supply system (100) comprising at least: one gas supply line (123) for supplying gas to the at least one gas-consuming appliance (300), said gas supply line being configured to be traversed by gas taken in the liquid state from a tank (200) and subjected to a pressure lower than a pressure of the gas in a headspace (201) of the tank (200), a first compression member (120) configured to compress the gas from the gas supply line (123) for supplying gas to the at least one gas-consuming appliance (300), a second compression member (130), characterised in that the first compression member (120) and the second compression member (130) alternately compress gas in the gaseous state from the gas supply line (123) and gas taken in the gaseous state from the headspace (201) of the tank (200).

Description

Title: Gas supply system for at least one gas consuming device fitted to a ship

The present invention relates to the field of ships the engine or engines of which is / are powered by natural gas and which also make it possible to contain and / or transport this liquefied natural gas.

Such ships thus conventionally include a vessel which contains natural gas in the liquid state. Natural gas is liquid at temperatures below -162 ° C at atmospheric pressure. These tanks are never perfectly thermally insulated so that the natural gas at least partially evaporates there. Thus, these tanks include both natural gas in liquid form and natural gas in gaseous form. This natural gas in gaseous form forms the vessel head and the pressure of this vessel head must be controlled so as not to damage the vessel. In a known manner, at least part of the natural gas present in the tank in gaseous form is thus used to supply, among other things, the engine or engines of the ship.

However, when the vessel is stationary, the consumption of gaseous natural gas by these engines is zero, or almost zero, as the natural gas present in the gaseous state in the tank is no longer consumed by these engines. Reliquefaction systems which allow the evaporated natural gas present in the tank to be condensed are thus installed on the vessel, in order to return it to this tank, in the liquid state.

The systems for supplying the engines and for reliquefying the gas which cannot be sent to these engines currently in use are very expensive. In particular, certain constituent elements of these power supply systems are provided in duplicate in order to ensure redundancy, that is to say to ensure continuous power supply to the motors, even in the event of failure of one of these elements. This is the case, for example, with compression devices which make it possible to compress the gas to pressures compatible with the needs of the engines. The present invention aims to solve this drawback by proposing a gas treatment system comprising fewer components than the current systems, thus making it possible to reduce the costs of implementing such systems, while being at least as efficient.

An object of the present invention thus relates to a gas supply system for at least one gas consuming device fitted to a ship, the supply system comprising at least:

- a gas supply line of at least one gas consuming device configured to be traversed by gas taken in liquid state from a tank and subjected to a pressure lower than a gas pressure in a tank head ,

- a first compression member configured to compress the gas coming from the gas supply line of at least one gas consuming device,

- a second compression member.

According to the invention, the first compression member and the second compression member alternately compress gas in the gaseous state from the gas supply line and gas taken in the gaseous state from a head of the vessel.

Advantageously, the first compression member and the second compression member are configured to independently supply the at least one gas consuming device. It is understood here that the two compression members are configured to ensure the supply of compressed gas to the gas consuming device. The two compression members are thus redundant with respect to each other.

The vessel includes the vessel configured to contain the liquefied gas. The term “top of the vessel” is understood to mean a portion of the vessel in which gas accumulates in the gaseous state generated by natural evaporation of the gas present in the liquid state in the rest of the vessel. The term “bottom of the tank” is understood to mean a portion of the tank which extends from a bottom wall of this tank and a plane parallel to this bottom wall and arranged, at most, at 20% of a total height of the tank, this total height being measured along a straight line perpendicular to the bottom wall of the tank between two opposite ends of this tank, along this straight line. Advantageously, the plane parallel to the bottom wall which participates in delimiting the "bottom of the tank" for wandering arranged at 10% of the total height of the tank.

The at least one appliance consuming evaporated gas for example wanders an electric generator of the DFDE (Dual Fuel Diesel Electric) type, that is to say a gas consuming appliance configured to supply the vessel with electricity, or a ship's propulsion engine, such as an ME-GI or XDF engine. It is understood that this is only an exemplary embodiment of the present invention and that provision can be made for the installation of appliances consuming different gases without departing from the context of the present invention.

According to the invention, the at least one gas consuming device advantageously makes it possible to consume, at least in part, the gas present in the gaseous state in the head of the vessel and thus prevent the latter from accumulating in the vessel. , which would lead to an increase in the pressure undergone by the tank, which could ultimately damage this tank.

According to the invention, the first compression member and the second compression member are interchangeable for powering the at least one gas consuming device. In other words, the first compression member and the second compression member are both adapted to compress the gas in the gaseous state to similar pressures and compatible with the needs of the at least one gas consuming device. In this way, if one of the two compression members fails, the other can take over and thus ensure a continuous supply of at least one gas-consuming device while maintaining an acceptable pressure in the tank, c 'That is to say a pressure which does not risk damaging this tank, at a lower cost.

Thus, the first compression member and the second compression member are both configured to compress the gas from the supply line from a pressure lower than a pressure of the gas present in the head of the vessel to at a pressure greater than or equal to this gas pressure in the vessel head. Each of the compression members is thus able to suck into the supply line when the latter is under negative pressure, that is to say subjected to a pressure lower than the pressure of the supply line. gas present in the head of the vessel, thanks to an expansion operated upstream of this supply line. According to an example of application of the invention, the pressure of the gas in the top of the vessel is equal to or substantially equal to 1.1 bar.

According to one characteristic of the present invention, the system comprises at least one heat exchanger configured to operate a heat exchange between the gas which circulates in the supply line and the gas taken in the liquid state from the tank. According to one embodiment of the present invention, the heat exchanger can for example be equipped with at least one first pass configured to wander supplied by the gas taken in the liquid state from the vessel of the vessel and at least a second pass configured for wandering supplied by gas subjected to a pressure lower than the gas pressure in a tank top. In other words, according to this embodiment, the second pass of the heat exchanger participates in forming the supply line.

The system according to this embodiment of the present invention comprises at least a first pump configured to feed the first pass of the heat exchanger, a second pump configured to feed the second pass of the heat exchanger, at least one means expansion being arranged on the supply line between the second pump and the second pass of the heat exchanger.

According to another embodiment of the present invention, the heat exchanger is equipped with a single pass which participates in forming the supply line and this heat exchanger is arranged in the tank, that is to say in contact with the liquid gas contained in this tank. According to this other embodiment of the present invention, a heat exchange therefore takes place between the gas subjected to a pressure lower than the pressure of the gas in the head cap which circulates in the first pass of the heat exchanger and the gas present in the liquid state in the tank with which the heat exchanger is in contact.

According to a mode of operation of the system according to the invenrion, the first compression member and the second compression member suck the gas taken from the vessel head. According to this operating mode, the first compression member and the second compression member are configured to compress the gas to the pressure compatible with the needs of the at least one gas consuming device. Alternatively, an expansion device can be arranged downstream of the first compression member and of the second compression member, this expansion device being configured to reduce the pressure of the gas compressed by the first and / or the second compression member to the pressure compatible with the needs of the at least one gas consuming device. In other words, according to this alternative, the gas is compressed to a pressure greater than the pressure compatible with the needs of the at least one gas consuming device, then the gas undergoes an expansion, that is to say a reduction of its pressure up to the pressure compatible with the needs of the at least gas consuming device.

According to one characteristic of the present invention, the feed system comprises as a compression member only the first compression member and the second compression member.

The feed system according to the invention may also include at least one reliquefaction system for the gas compressed by the first compression member and / or by the second compression member. Such a reliquefaction system advantageously makes it possible to recycle the gas in the gaseous state which is not consumed by at least one gas consuming device by condensing it and then returning it to the tank.

According to one embodiment of the present invention, the reliquefaction system comprises at least a first heat exchanger equipped with at least a first pass configured to be traversed by gas compressed by the first compression member and / or by the second member. compression and at least one second pass configured to be traversed by gas taken in the gaseous state from the top of the vessel. In other words, it is understood that the first heat exchanger of this reliquefaction system is configured to operate a heat exchange between the gas compressed by the first compression member and / or by the second compression member and the gas withdrawn in the state. gas in the top of the tank. For example, the reliquefaction system can also include at least a second heat exchanger configured to operate a heat exchange between the compressed gas which leaves the first heat exchanger and gas taken from the tank in the liquid state. In other words, this second heat exchanger comprises at least a first pass configured to be supplied with the compressed gas which leaves the first heat exchanger and at least a second pass configured to be supplied with the gas withdrawn in the liquid state from the tank.

According to a characteristic of this embodiment of the present invention, at least a first duct is arranged between the first pump and the first pass of the heat exchanger and at least one additional duct is arranged between the first duct and the second exchanger. thermal, at least a first control valve being arranged on this additional duct. In other words, it is understood that the first pump is configured to feed, at least, the first pass of the heat exchanger and the second heat exchanger of the reliquefaction system.

The first control valve arranged on the additional duct, that is to say upstream of the second heat exchanger with respect to a direction of gas flow in this additional duct, is configured to take an open position in which it allows the circulation of liquid gas in the additional conduit and a closed position in which it prohibits the flow of gas in this additional conduit. It is understood that this is only an exemplary embodiment and that provision could be made for the second pump to supply only the first pass of the heat exchanger and for a third pump to be put into operation. place to supply the second heat exchanger without departing from the context of the present invention.

Alternatively, the reliquefaction system is devoid of the second heat exchanger and the compressed gas which leaves the first heat exchanger is returned directly to the tank, for example via a bubbling member placed at the bottom of the tank. According to this alternative, the gas from the first heat exchanger is then released in the form of bubbles which condense on contact with the gas present in the liquid state in the tank.

It is understood that these are only exemplary embodiments and that any other reliquefaction system compatible with the invention could be envisaged. According to one characteristic of the present invention, the first compression member is configured to wander supplied with gas having a pressure of between 0.35 and 0.7 bar and to compress this gas to a pressure of between 2 bar and 13 bar. bar and in which the second compression member is configured to wander supplied with gas having a pressure equivalent to 1 bar and to compress it to a pressure of between 5 bar and 20 bar.

According to a first exemplary embodiment of the present invention, at least one pipe is arranged between the tank top and an intermediate inlet of the first compression member, at least one regulating member being arranged on this at least one pipe.

For example, the regulator can wander a turn or nothing valve, that is to say a valve configured to take an open position in which it allows the circulation of gas in the pipe and a closed position in which it blocks. the circulation of gas in this pipe.

According to this first exemplary embodiment, the first compression member comprises at least one main inlet through which it is supplied with the gas coming from the supply line and at least the intermediate input through which it is supplied with gas taken from the supply line. gaseous state in the tank top. In other words, it will be understood that the first compression member is adapted to be supplied, alternately or simultaneously, with evaporated gas and with gas taken directly in the gaseous state from the top of the tank.

Thus, according to this first exemplary embodiment, if the second compression member is faulty, the regulator allows the gas to pass through the pipe so that the gas taken in the gaseous state in the vessel head can roam compressed. by the first compression member in order to be sent to the at least one gas consuming device. According to this first exemplary embodiment, the second compression member is configured to supply the at least one gas consuming device with gas taken in the gaseous state from the vessel head. In other words, whatever evening the compression member on which a failure occurs, the power supply of at least one consumer device of gas by the gas taken from the gaseous erar in the head of the vessel is ensured, and thus, the pressure in the vessel is maintained at an acceptable value for this vessel.

According to a second exemplary embodiment of the present invention, the first compression member and the second compression member are mounted in series with respect to the other. According to this second exemplary embodiment, at least a first conduit esr arranged between an outlet of the first compression member and an inlet of the second compression member, at least one pressure regulating means being arranged on this at least one first conduit. For example, the pressure regulating means can wander an expansion member, that is to say a member configured to reduce a pressure of the gas flowing in this first conduit. Advantageously, this allows the first compression member to compress the gas evaporated by the heat exchanger with a pressure difference sufficient to ensure its correct operation and limit its wear. The gas thus compressed by the first compression member is then released by the pressure regulating means before being compressed by the second compression member to the pressure compatible with the needs of the at least one gas consuming device. .

According to this second exemplary embodiment, the first compression member esr for example configured to wander supplied with gas having a pressure of between 0.35 bar and 0.7 bar to compress it to a pressure of between 2 bar. 6 bar, the second compression member esr for its part configured to wander supplied with gas having a pressure equivalent, or substantially equivalent, to 1 bar to compress it to a pressure between 5 bar and 20 bar.

Alternatively, this series of compressions compresses the gas to a pressure greater than the needs of the at least one gas consuming device and at least one expansion device arranged between the second compression member and the at least one consuming device. gas, this expansion device then being configured to reduce the pressure of the gas compressed by the first compression member and by the second compression member to the pressure compatible with the needs of the at least one gas consuming device. According to the second exemplary embodiment of the present invention, at least a second pipe can be arranged between an outlet of the second pass of the first heat exchanger and an inlet of the first compression member, at least one first flow regulation means being arranged on this at least a second drive. This first flow regulation means for example wanders a turn or nothing valve, that is to say a valve configured to take an open position in which it allows gas to circulate in the second pipe and at least one closed position. in which it prohibits this circulation of gas in the second lead. Thus, according to this second exemplary embodiment, when the first compression member fails, the gas consuming device is supplied with gas taken in the gaseous state from the head of the vessel and compressed by the second compression member. When the second compression member is faulty, the first flow control means can be moved to the open position in order to allow the gas taken in the gaseous state in the head of the vessel to feed the first compression member and thus ensure the supply of the gas consuming device with gas taken in gaseous state from the head of the vessel.

Alternatively, the first flow rate regulator means wanders a pressure regulator. According to this alternative, when the second compression member fails, the gas withdrawn in the gaseous state in the vessel head is directed towards the second conduit, along which it is derated by the first flow regulation means, c 'that is to say that its pressure is reduced, to a pressure equivalent to the pressure of the gas issuing from the supply line, that is to say a pressure between 0.35 bar and 0.7 bar. This alternative thus makes it possible, advantageously, to supply the first compression member, simultaneously, with gas taken in the gaseous state in the head of the vessel and in gas taken in the liquid state in the vessel and evaporated by the line of. food.

Thus, the second exemplary embodiment of the present invention makes it possible to ensure an uninterrupted supply of at least one gas consuming device, at least, with gas taken in the gaseous state from the head of the vessel, which allows to maintain a acceptable pressure in the tank, that is to say a pressure which does not risk damaging this tank.

According to one characteristic of the present invention, the supply system comprises at least one means for distributing the gas in the liquid state coming from the heat exchanger in a bottom of the tank. For example, this distribution means is formed by a ramp equipped with a plurality of orifices. According to this example, the orifices are distributed over a longitudinal dimension of the ramp, each of these orifices being adapted to allow the ejection of gas in the liquid state from the heat exchanger.

Optionally, an outlet of the second heat exchanger of the reliquefaction system by which gas in the liquid or two-phase state leaves this second heat exchanger can also be connected to this distribution means in order to be returned to the tank. Advantageously, such a ramp makes it possible to distribute the gas in the liquid state coming from the heat exchanger and / or from the second heat exchanger in the bottom of the tank so that it makes it possible to lower the overall temperature of the gas present. in the liquid state in this tank, and thus contributes to limiting the phenomenon of evaporation which tends to generate the accumulation of gas in the gaseous state in the tank. Alternatively, the distribution means is formed by a simple pipe.

The present invention also relates to a liquefied gas transport vessel, comprising at least one tank of a liquefied gas cargo, at least one appliance consuming evaporated gas and at least one gas supply system for the appliance consuming gas. gas according to the invention. The term “a tank of a liquefied gas cargo” is understood to mean both a tank which serves both for transporting liquefied gas and as a tank for liquefied gas used as fuel for supplying at least one consuming device. gas, a tank which serves only as a liquefied gas tank for supplying the at least one gas consuming device.

According to one characteristic of the present invention, the vessel comprises at least a first gas consuming device configured to be supplied with compressed gas at a first pressure, and at least a second consuming device. gas configured to be supplied with gas compressed at a second pressure, the first gas consuming apparatus and the second gas consuming apparatus both being configured to be supplied by the at least one supply system according to the invention, and the first supply pressure of the first gas consuming apparatus being greater than the second supply pressure of the second gas consuming apparatus.

The present invention also relates to a system for charging or discharging a gas in the liquid state which combines at least one means on land and at least one vessel for transporting gas in the liquid state according to the invention.

Finally, the invention relates to a method of loading or unloading a gas in the liquid state from a gas transport vessel according to the invention.

Other characteristics, details and advantages of the invention will emerge more clearly on reading the description which follows on the one hand, and of an exemplary embodiment given by way of indication and not limiting with reference to the appended drawings on the other hand. share, on which:

[Fig. 1] illustrates, schematically, a gas supply system of at least one gas consuming device according to a first embodiment of the present invention;

[Fig. 2] illustrates, schematically, a first mode of operation of the gas supply system according to the first embodiment illustrated in Figure 1;

[Fig. 3] illustrates, schematically, a second mode of operation of the gas supply system according to the first embodiment illustrated in Figure 1;

[Fig. 4] illustrates, schematically, a third mode of operation of the gas supply system according to the first embodiment illustrated in Figure 1;

[Fig. 5] illustrates, schematically, the gas supply system according to the first embodiment of the present invention, in which a first compression member fails;

[Fig. 6] illustrates, schematically, the gas supply system according to the first exemplary embodiment of the present invention, in which a second compression member fails;

[Fig. 7] illustrates, schematically, the gas supply system of at least one gas consuming device according to a second embodiment of the present invention;

[Fig. 8] illustrates, schematically, a first mode of operation of the gas supply system according to the second embodiment illustrated in Figure 7;

[Fig. 9] illustrates, schematically, a second mode of operation of the gas supply system according to the second embodiment illustrated in Figure 7;

[Fig. 10] illustrates, schematically, a third mode of operation of the gas supply system according to the second embodiment illustrated in Figure 7;

[Fig. 11] illustrates, schematically, the gas supply system according to the second embodiment of the present invention in which a first compression member fails;

[Fig. 12] illustrates, schematically, the gas supply system according to the second embodiment of the present invention, in which a second compression member fails;

[Fig. 13] illustrates, schematically, a fourth mode of operation of the gas supply system according to the second embodiment illustrated in Figure 7

[Fig. 14] illustrates, schematically, a fifth mode of operation of the gas supply system according to the second embodiment illustrated in Figure 7

[Fig. 15] is a cut-away schematic representation of an LNG vessel tank and a terminal for loading and / or unloading this tank.

In the remainder of the description, the terms “upstream” and “downstream” are understood in a direction of circulation of a gas in the liquid, gaseous or two-phase state through the element concerned. In Figures 2 to 6 and 8 to 14, the solid lines represent portions of the circuit in which gas circulates in the liquid, gaseous or two-phase state, while the dotted lines represent portions of the circuit in which gas does not circulate. Finally, the space of the tank 200 occupied by the gas in the gaseous state is called “sky 201 of the tank 200” and the terms “gas supply system 100 of at least one gas consuming appliance 300”. , "Power system 100" and "system 100" will be used without distinction.

The description given below relates to two specific examples of application of the present invention in which the vessel 200 of a ship contains natural gas, that is to say a gas predominantly composed of methane. It is understood that this is only an example of application and that the gas supply system 100 of at least one gas consuming appliance 300 according to the invention can be used with other types. gases, such as, for example, hydrocarbon or hydrogen gases. According to the invention, the vessel 200 of this vessel can serve exclusively as a reservoir containing the gas intended for the gas supply of at least one gas consuming appliance 300, or, alternatively, this vessel 200 can serve both gas tank and gas transport tank.

FIGS. 1 and 7 thus firstly illustrate, schematically, the gas supply system 100, when stopped, according to, respectively, the first embodiment of the present invention and the second embodiment of the present invention. invention. The system 100 comprises at least one heat exchanger 110, at least a first compression member 120, at least a second compression member 130 and at least one gas consuming device 300. According to any one of the first and second examples of Embodiments of the present invention illustrated herein, the system 100 further comprises a gas reliquefaction system 400.

Advantageously, according to the two exemplary embodiments of the invention, the supply system 100 comprises only two compression members as compression means for supplying the gas consuming device 300, for example an engine. This is particularly advantageous given the very high costs of these components and the obligation to constantly have a back-up means to supply the gas consuming appliance 300. The reliquefaction system 400 according to the invention comprises at least a first heat exchanger 410 and / or at least a second heat exchanger 420 arranged in series for at least one flow which passes through them. The first heat exchanger 410 comprises at least a first pass 411 configured to be traversed by gas compressed by the first compression member 120 and / or by the second compression member 130, and at least one second pass 412 configured to be traversed by gas taken in the gaseous state in the top 201 of the tank 200. The second heat exchanger 420 has for its part at least one first pass 421 configured to be traversed by the compressed gas which leaves the first pass 411 of the first heat exchanger 410 and at least one second pass 422 configured to be traversed by gas taken in the liquid state in the tank 200. As described below, this gas taken in the liquid state in the tank 200 can be expanded, c 'that is to say undergo a decrease in its pressure before being sent to the second pass 422 of the second heat exchanger 420.

The first heat exchanger 410 is thus configured to operate a heat exchange between the compressed gas and the gas taken, in the gaseous state, from the top 201 of the tank 200. The result is that the compressed gas leaves the first pass 411. of the first heat exchanger 410 in the gaseous or two-phase state, that is to say a mixture of gas and liquid, and that the gas taken in the gaseous state in the head 201 of the tank 200 is heated by its passage through the second pass 412 of the first heat exchanger 410. The gas heated by its passage through the first heat exchanger 410 is then sent to one of the compression members 120, 130 in order to be compressed and then sent, at least in part, to at least one gas consuming appliance 300.

The second heat exchanger 420 is for its part configured to operate a heat exchange between the two-phase gas issuing from the first pass 411 of the first heat exchanger 410 and the gas taken in the liquid state in the tank 200. The two-phase gas is condensed. by its passage through the second heat exchanger 420 in order to be then returned to a bottom 203 of the tank 200 and the gas withdrawn in the liquid state in the tank 200 is in turn heated by its passage through the second heat exchanger 420.

According to an exemplary embodiment not illustrated here, the reliquefaction system may be without the second heat exchanger. According to this exemplary embodiment, the first pass of the first heat exchanger is connected for example to a bubbling member arranged in the bottom of the tank. The gas in the two-phase state from the first heat exchanger is then ejected into the bottom of the tank in the form of bubbles which condense on contact with the gas in the liquid state present in the bottom of this tank.

The term “bottom 203 of the tank 200” is understood to mean a portion of the tank 200 which extends between a bottom wall 202 of the tank 200 and a plane parallel to this bottom wall 202 and arranged, at most, at 20%. of the total height h of the tank, this total height h being measured along a straight line perpendicular to the bottom wall 202 of the tank 200 between two opposite ends of this tank 200, along this straight line. Advantageously, the plane parallel to the bottom wall 202 which participates in delimiting the “bottom of the tank” can be arranged at 10% of the total height h of the tank.

It is understood that these are only exemplary embodiments of the present invention and that any other reliquefaction system compatible with the invention could be used without departing from the context of the present invention. For example, a reliquefaction system could be provided which comprises a separate refrigerant fluid circuit.

According to the invention, the supply system 100 comprises at least one supply line 123 of the at least one gas consuming device 300 configured to be traversed by gas taken in the liquid state in the tank 200 and subjected at a pressure lower than a pressure of the gas in a head 201 of the tank 200. According to an example of application of the present invention, the gas in the head 201 of the tank 200 has a pressure equivalent to, or substantially equivalent to the pressure atmospheric, that is to say a pressure of the order of 1 bar.

The supply system 100 according to the invention comprises at least one pump 141 arranged in the bottom 203 of the tank 200 and at least one expansion means 170 arranged between this pump 141 and the supply line 123, the pump 141 and way to trigger 170 being configured to ensure the supply of the supply line 123. The following description gives an exemplary embodiment of this supply line 123 but it is understood that this supply line 123 could take a different form without depart from the context of the present invention.

Thus, at least a first duct 101 is arranged between a first pump 140 and a first pass 111 of the heat exchanger 110. At least a second duct 102 is arranged between a second pump 141 and a second pass 112 of the exchanger. heat 110. The first pump 140 and the second pump 141 are both arranged at the bottom 203 of the tank 200, so as to take the gas in the liquid state to send it to the first and second passes 111, 112 of the heat exchanger 110. A third duct 103 extends between the second pass 112 of the heat exchanger 110 and the first compression member 120, this second pass 112 and the third duct 103 forming, at least partially, the supply line 123 of at least one gas consuming appliance 300 mentioned above. More particularly, this third duct 103 extends between the second pass 112 of the heat exchanger 110 and a main inlet 121 of the first compression member 120.

According to the invention, at least one expansion means 170 is arranged on the second duct 102, that is to say between the second pump 141 and the second pass 112 of the heat exchanger 110. This expansion means 170 is thus configured to expand the gas in the liquid state conveyed by the second pump 141, that is to say to decrease the pressure of this gas in the liquid state, before the latter joins the second pass 112 of the heat exchanger 110. In other words, the expansion means 170 arranged upstream of the heat exchanger 110 makes it possible to create a pressure difference between the gas which circulates in the first pass 111 and the gas which circulates in the second pass 112 of this heat exchanger 110. The gas in the liquid state circulating in the first pass 111 of the heat exchanger 110 thus has an identical pressure, or substantially identical to the pressure of the gas contained in the heat exchanger 110. liquid state in the tank 200 and the gas circulating in the second pass 112 of the ec heat exchanger 110 present as to him a pressure lower than the pressure of the gas contained in the liquid state in the tank 200. The gas which thus circulates in the second pass 112 vaporizes as it travels in the second pass 112 of the heat exchanger 110.

As a result, a heat exchange takes place in this heat exchanger 110 so that the gas in the liquid state is cooled as it passes through the first pass 111 of the heat exchanger 110 and the gas in the derated liquid state is evaporated by its passage through the second pass 112 of the heat exchanger 110.

According to an exemplary embodiment of the invention not illustrated here, the heat exchanger could comprise a single first pass supplied with the gas subjected to a pressure lower than the pressure of the gas in the head cap and submerged in contact with the gas. contained in the liquid state in the tank. According to this exemplary embodiment, a heat exchange similar to that which has just been described then takes place between the derated gas which circulates in the heat exchanger and the liquid gas in contact with which this heat exchanger is arranged. An additional duct 423 is arranged between the first duct 101 and the second pass 422 of the second heat exchanger 420, at least a first regulating valve 171 being arranged on this additional duct 423. This first regulating valve 171 is configured to take a position open in which it allows the circulation of liquid gas in the additional duct 423 and a closed position in which it prohibits the circulation of gas in this additional duct

423.

A fourth duct 104 is arranged between the first pass 111 of the heat exchanger 110 and the bottom 203 of the tank 200. As illustrated, this fourth duct 104 is more specifically arranged between the first pass 111 of the heat exchanger. heat 110 and a means 210 for distributing the gas in the liquid state in the bottom 203 of the tank 200.

According to the examples illustrated here, this distribution means 210 is formed by a ramp 212 arranged at the bottom 203 of the tank 200. As will be more fully derailed below, this ramp 212 advantageously makes it possible to distribute the cooled gas by its passage. through the heat exchanger 110 in the bottom 203 of the tank 200. According to a exemplary embodiment not illustrated here, this distribution means 210 can wander simply formed by the fourth duct 104 which then opens directly into the bottom 203 of the tank 200.

A fifth conduit 105 extends between the first compression member 120 and a sixth conduit 106 for its part connected to at least one gas consuming device 300. In other words, the gas withdrawn in the liquid state in the tank 200 by the second pump 141 and evaporated by its passage through the second pass 112 of the heat exchanger 110 is intended for the supply of at least one gas consuming device 300.

It should also be noted that a seventh duct 107 is arranged between the second compression member 130 and the sixth duct 106. This seventh duct 107 makes it possible in particular to supply the at least one gas consuming appliance 300 with gas taken from the state. gas in the top 201 of the tank 200 and compressed by the second compression member 130.

In other words, it will be understood that the first compression member 120 and the second compression member 130 are both suitable for supplying, independently, at least one gas consuming device 300. Thus, the first compression member 120 and the second compression member 130 are both configured to compress the gas to a pressure compatible with the needs of the gas consuming apparatus 300, i.e. an absolute pressure between 5 bar and 20 bar or a pressure greater than 150 bar depending on the type of gas consuming device 300 to be supplied. The first compression member 120 is also suitable for compressing the gas coming from the second pass 112 of the heat exchanger 110 to a pressure lower than a pressure of the gas present in the gaseous state in the head 201 of the vessel 200. , up to a pressure greater than or equal to this pressure of the gas present in the gaseous state in the top 201 of the vessel 200. For example, the first compression member 120 is suitable for compressing the gas issuing from the second pass 112 of the heat exchanger 110 with an absolute pressure between 0.35 bar and 0.7 bar up to the pressure compatible with the needs of at least one gas consuming device 300, greater than 1.1 bar, for example a pressure between 5 bar and 20 bar.

The same applies to the second compression member 130 which is adapted to compress the gas coming from the second pass 112 of the heat exchanger 110 to a pressure lower than the pressure of the gas present in the gaseous state in the gas. head 201 of the vessel 200 up to a pressure greater than or equal to this pressure of the gas present in the gaseous state in the head 201 of the vessel 200. For example, the second compression member 130 is suitable for compressing the gas obtained from the second pass 112 of the heat exchanger 110 at an absolute pressure of between 0.35 bar and 0.7 bar up to the pressure compatible with the needs of the at least one gas consuming appliance 300, this is ie a pressure greater than 1.1 bar, for example a pressure between 5 bar and 20 bar.

According to an exemplary embodiment not illustrated here, the first compression member and the second compression member are configured to compress the gas which supplies them respectively to a pressure greater than the pressure compatible with the needs of the at least one consumer device. gas. According to this exemplary embodiment, at least one expansion device is arranged downstream of the first compression member and of the second compression member and upstream of the gas consuming device, this expansion device being configured to reduce the gas pressure. compressed by the first compression member and / or by the second compression member to the pressure compatible with the needs of the gas consuming device. For example, this expansion device can thus be arranged on the sixth duct.

An eighth duct 108 extends between the sixth duct 106 and the reliquefaction system 400 described above, that is to say between the sixth duct 106 and the first pass 411 of the first heat exchanger 410 of this reliquefaction system. 400. As will be more fully detailed below, at least a second control valve 180 is arranged on this eighth conduit 108 in order to allow or prohibit the passage of compressed gas which circulates in the sixth conduit 106. For example, the second control valve 180 can be an “all or nothing” valve, that is to say a valve configured to take an open position in which it allows the passage of compressed gas in the eighth conduit 108 and a closed position in which it prohibits the flow of gas in this eighth conduit 108.

Finally, a ninth duct 109 is arranged between the second pass 412 of the first heat exchanger 410 and one or the other of the compression members 120, 130.

In other words, this ninth duct 109 ensures the supply of the first compression member and / or of the second compression member 130 with gas taken in the gaseous state in the head 201 of the tank 200 and intended for the supply of the gas. at least one gas consuming device 300. According to the first embodiment example illustrated in FIG. 1, a pipe 119 is also arranged between the ninth duct 109 and an intermediate inlet 122 of the first compression member 120, at least one regulation member 181 being arranged on this pipe 119. It is noted that the intermediate inlet 122 of the first compression member 120 through which this first compression member 120 is supplied with gas taken in the gaseous state in the head 201 of the tank

200 is separate from the main inlet 121 of this first compression member 120 through which the latter is supplied with evaporated gas by its passage through the heat exchanger 110. These two separate inlets allow a supply of the first compression member 120 at two different compression levels. Indeed, as previously mentioned, the evaporated gas leaves the heat exchanger 110 at a pressure lower than the pressure of the gas present in the gaseous state in the top 201 of the tank 200. For example, the evaporated gas leaves the heat exchanger 110 at an absolute pressure less than 1 bar, between 0.35 bar and 0.7 bar, while the gas taken in the gaseous state in the top 201 of the tank 200 has an absolute pressure of about 1 bar. The intermediate inlet 122 thus allows the gas taken in the gaseous state in the top 201 of the tank 200 to join the compressed flow after intermediate compression of the flow coming from the heat exchanger 110. This is particularly the case when the first compression member 120 and / or the second compression member 130 are multistage. According to the second exemplary embodiment illustrated in FIG. 7, at least a first conduit 128 is arranged between the fifth conduit 105 and the ninth conduit 109, at least one pressure regulating means 182 being arranged on this first conduit 128. Thus, this first conduit 128 extends between an outlet 124 of the first compression member 120 and an inlet 131 of the second compression member 130 and allows the second compression member 130 to be supplied with gas evaporated by the heat exchanger 110 and compressed by the first compression member 120. The pressure regulating means 182 can for example wander an expansion member configured to reduce the pressure of the gas compressed by the first compression member 120 before this gas feeds the second compression member 130. In addition, this pressure regulating means 182 is configured to take a closed position in which it prohibits the flow of gas in the first pipe. re 128. Advantageously, this pressure regulating means 182 makes it possible to have a pressure difference between the inlet 125 and the outlet 124 of the first compression member 120 sufficient to allow optimal operation of this first compression member 120. Otherwise dir, the gas is compressed to a first pressure by the first compression member 120, then it is expanded by the pressure regulating means 182 before being again compressed by the second compression member 130 to the compatible pressure with the needs of the gas consuming apparatus 300. For example, the first compression member 120 is configured to compress the gas from a pressure of between 0.35 bar and 0.7 bar to a pressure of between 2 bar and 6 bar. The gas is then released to a pressure of about 1 bar by the pressure regulating means 182, then the second compression member 130 is configured to compress this gas from its pressure of 1 bar to a pressure between 5 bar and 20 bar, i.e. the pressure compatible with the needs of the gas consuming device 300.

At least a second conduit 129 is arranged between the ninth conduit 109 and an inlet 125 of the first compression member 120, at least one first flow rate regulating means 183 being arranged on this second conduit 129. According to this second embodiment of the present invention, a second means of flow regulation 184 is further arranged on the fifth conduit 105, that is to say between the first compression member 120 and the gas consuming apparatus 300. For example, the first flow regulating means 183 and the second flow regulation means 184 can wander "turn or nothing" valves, that is to say valves configured to take an open position in which they allow the passage of gas in the pipe on which they are arranged or a closed position in which they prevent the passage of gas in this conduit. Alternatively, and as will be derailed more fully hereinafter with reference to FIG. 13, the first flow rate regulating means 183 wanders a pressure regulating member, that is to say a member configured to reduce a flow rate. pressure of the gas passing through it. According to yet another alternative, the first flow rate regulating means 183 wanders a turn-or-nothing valve and a supporting branch of a pressure regulating member wanders arranged in parallel with this second pipe 129 carrying the first pressure regulating means. flow rate, the gas being adapted to take the second conduit 129 or the branch parallel to this second conduit 129 depending on the operating mode of the system 100.

Finally, the second exemplary embodiment of the present invention differs from the first exemplary embodiment in that two gas recirculation pipes - not shown here - are formed in parallel, respectively, of the first compression member 120 and of the second pressure member. compression 130, each of these recirculation pipes carrying at least one pressure control means. Advantageously, these pressure control means allow the first compression member 120 and the second compression member 130 to compress the gas supplied to it at different pressures depending, for example, on the needs of the at least one consuming device. of gas 300.

For example, at least one gas consuming device 300 is wandering an electric generator of the DFDE (Dual Fuel Diesel Electric) type, that is to say a gas consuming device configured to supply the vessel with electricity. The gas-consuming device 300 is also afraid of at least one propulsion motor vessel, such as an ME-GI or XDF engine. It is understood that this is only an exemplary embodiment of the present invention and that provision can be made for the installation of appliances consuming different gases without departing from the context of the present invention.

With reference to the first exemplary embodiment of the present invention, we will now describe three operating modes, a first operating mode in which only part of the gas present in the gaseous state in the head 201 of the tank 200 is consumed by at least one gas consuming device 300 and in which another part of this gas present in the gaseous state in the top 201 of the tank 200 is reliquefied by the reliquefaction system 400 before being returned to the bottom of the the tank 203 and a second and a third operating modes in which the quantity of gas present in the gaseous state in the head 201 of the tank 200 is insufficient to supply the at least one gas consuming device 300 and in which gas is taken in the liquid state in the tank 200 and evaporated by the heat exchanger 110 in order to overcome this insufficiency. As described below, the second operating mode differs from the third operating mode in that in the second operating mode at least one gas consuming device 300 is supplied with gas compressed by the first compression member 120. and by gas compressed by the second compression member 130 while in the third mode of operation, the at least one gas consuming device 300 is supplied with gas compressed only by the first compression member.

FIG. 2 thus illustrates the first mode of operation of the system 100 according to the first exemplary embodiment of the present invention. As shown, at least one gas consuming device 300 is supplied with gas taken in the gaseous state in the top 201 of the tank 200 which passes through the first heat exchanger 410 before being compressed by the second control member. compression 130 to a pressure compatible with the needs of this at least one gas consuming device 300. Part of the gas thus compressed supplies the gas consuming device 300, while another part of this compressed gas is sent to the reliquefaction system 400. This situation arises for example when the gas consuming apparatus 300 consumes less than the quantity of gas which evaporates in the tank 200.

The part of the compressed gas sent to the reliquefaction system 400 is thus first of all partially cooled by heat exchange with gas taken in the gaseous state in the top 201 of the tank 200, within the first heat exchanger 410 , then this gas which leaves the first heat exchanger 410 in the gaseous or two-phase state ends its condensation by an exchange of heat with gas taken in the liquid state in the tank 200 and expanded by the first control valve 171, this heat exchange being carried out within the second heat exchanger 420. The gas thus condensed at the outlet of the second heat exchanger 420 is returned to the bottom of the vessel via the fourth pipe 104. As previously mentioned, this fourth pipe 104 is connected to a ramp 212 which has a plurality of orifices 211 configured to allow the release and distribution over a large area of the gas in the liquid state which reaches it.

Also, the heat exchanger 110 is not powered, that is, the second pump 141 is stopped. Indeed, as previously described, this heat exchanger 110 makes it possible to evaporate the gas taken in the liquid state in the tank 200 in order to supply the gas consuming appliance 300. When the gas present in the gaseous state in the top 201 of the tank 200 is sufficient to supply this gas consuming device 300, this heat exchanger 110 does not need to operate and the second pump 141 can therefore be stopped.

On the other hand, when the quantity of gas present in the gaseous state in the head 201 of the tank 200 is insufficient to supply the gas consuming device 300, then the second pump 141 is put into operation so as to supply the exchanger. heat 110. This is for example what is illustrated in FIG. 3 which represents the second mode of operation of the system 100 according to the first exemplary embodiment of the present invention. Thus, according to this second operating mode, the first pump 140 and the second pump 141 are both put into operation in order to supply the heat exchanger 110 and thus supply the device. consumer of gas 300 in evaporated gas and the reliquefaction system 400 is for its part stopped, that is to say that the second control valve 180 is in its closed position and the first control valve 171 prevents gas from circulating in the additional pipe 423, all of the gas present in the gaseous state in the top 201 of the tank 200 and compressed by the second compression member 130 being consumed by the gas consuming device 300. Thus , according to this second mode of operation, at least one gas consuming device 300 is supplied with gas taken in the liquid state in the tank 200, evaporated in the heat exchanger 110 and compressed by the first compression member 120 and also by gas taken in the gaseous state in the top 201 of the tank 200 and compressed by the second compression member 130.

As previously mentioned, the supply system 100 according to the invention also makes it possible, advantageously, to use only the first compression member 120 to supply the at least one gas consuming device 300 with gas drawn off at the gaseous state in the top 201 of the tank 200 and with gas taken off in the liquid state and evaporated. Such an operating mode corresponds to the third operating mode illustrated in FIG. 4.

This third operating mode differs from the second operating mode in particular in that the second compression member 130 is stationary and the regulating member 181 is in its open position, thus allowing the circulation of gas in the pipe 119. As described above, the gas evaporated by its passage through the heat exchanger 110 reaches the first compression member 120 in which it is compressed to a pressure compatible with the needs of the gas consuming apparatus 300. The gas taken in the gaseous state in the top 201 of the tank 200 passes through the first heat exchanger 410 in which it undergoes no other temperature or pressure change than those related to its suction and losses of load inherent in the transport of this type of fluid, and then follows the pipe 119 through which it joins the first compression member 120 through its intermediate inlet 122. The first compression member 120 is then configured to compress this gas to the pressure compatible with the needs of the gas consuming device 300.

According to this third mode of operation, the first compression member 120 for example wanders a multistage compressor. Thus, the evaporated gas which feeds the first compression member 120 through its main inlet 121 is compressed to a pressure equivalent to the pressure of the gas present in the gaseous state in the head 201 of the tank 200. The intermediate inlet 122 of the first compression member 120 is then arranged so that the gas taken in the gaseous state in the top 201 of the tank 200 mixes with the gas evaporated at a point of the first compression member 120 at which this gas evaporated esr already compressed to the pressure of the gas present in the top 201 of the tank 200. The first compression member 120 is then adapted to compress the gas mixture thus formed to the pressure compatible with the needs of the at least a gas consuming appliance 300.

Advantageously, this third mode of operation also makes it possible to alleviate a possible failure of the second compression member 130, that is to say to maintain a supply of at least one gas consuming device 300 with gas taken from the gas. gaseous state in the head 201 of the tank 200 and by gas taken in the liquid state in the tank 200 and evaporated by the heat exchanger 110.

There is also a fourth operating mode, not illustrated here, dir "at equilibrium" in which the quantity of gas contained in the top of the vessel in the gaseous state is equivalent, or substantially equivalent to the need for at least a gas consuming appliance. According to this fourth operating mode, the first pump and the second pump are thus stopped, and neither the heat exchanger nor the reliquefaction system operates, the gas consuming device then being supplied by the first member. compression or by the second compression member which sucks the gas in the gaseous state present in the top 201 of the tank 200.

FIG. 5 illustrates the gas supply system 100 according to the first exemplary embodiment of the present invention in which the first compression member 120 fails. It will be understood from this FIG. 5 that in the event of failure of the first compression 120, the supply of the gas consuming appliance 300 remains ensured by the gas taken in the gaseous state in the top 201 of the tank 200, which also makes it possible to maintain the pressure in the tank 200 at a value acceptable. In this situation, this FIG. 5 illustrates a mode identical to the first mode of operation of the system 100 illustrated in FIG. 2.

FIG. 6 illustrates for its part the first mode of operation applied to the first exemplary embodiment, in which the second compression member 130 has failed. As illustrated, in the event of failure of the second compression member 130, the regulating member 181 is open in order to allow the gas taken in the gaseous state in the vessel head 200 to reach the first compression member 120 in in which its pressure is increased to the pressure compatible with the needs of the gas consuming appliance 300. This figure illustrates the first mode of operation, the reliquefaction system is active, that is to say the second valve control 180 is open and the first pump 140 operates to supply the second heat exchanger 420 while the heat exchanger 110 is stopped. For these aspects, the description of Figure 2 applies mutatis mutandis to Figure 5.

The gas supply system 100 according to the first embodiment of the present invention thus allows an uninterrupted supply of at least one gas consuming device 300 with gas taken in the gaseous state in the head 201 of the tank. 200, which ensures that the pressure in the tank 200 is maintained at an acceptable value for this tank 200, that is to say a pressure which does not risk damaging the latter. In parallel with this aspect, the two compression members are also designed to suck the gas evaporated in the first pass 112 of the heat exchanger 110 at an absolute pressure of between 0.35 bar and 0.7 bar and to bring this gas to an absolute pressure between 5 bar and 20 bar, or greater than 150 bar depending on the gas consuming device 300 concerned.

The description of the first mode of operation which has just been given with reference to the first exemplary embodiment applies mutatis mutandis to the first mode of operation of the second exemplary embodiment illustrated in FIG. 8. Otherwise said, according to the first mode of operation, the second pump 141 is stopped, the pressure regulating means 182, the first flow regulating means 183 and the second flow regulating means 184 are all three in their position closed and the first compression member 120 is stopped, the supply of the gas consuming device 300 being provided by the gas taken in the gaseous state in the top 201 of the tank 200 and compressed by the second member compression 130. For the operation of the reliquefaction system, the description given above with reference to Figure 2 applies.

Concerning the second mode of operation illustrated in FIG. 9, the system 100 according to the second exemplary embodiment differs from the first exemplary embodiment, in particular in that the first compression member 120 and the second compression member 130 operate in series, on gas flow.

FIG. 9 illustrates this second mode of operation applied to the second exemplary embodiment of the present invention. In the following description, only the elements which distinguish the second mode of operation applied to the second exemplary embodiment from the second mode of operation applied to the first exemplary embodiment are described.

As illustrated, according to this second exemplary embodiment, the evaporated gas which leaves the second pass 112 of the heat exchanger 110 is first of all compressed by the first compression member 120, then it takes the first pipe 128 for join the second compression member 130 in which it undergoes a second compression before supplying the gas consuming device 300. In other words, the pressure regulating means 182 allows the circulation of gas in the first pipe 128, while the first flow regulating means 183 and second flow regulating means 184 are in their closed position. According to the invention, the evaporated gas leaves the heat exchanger 110 at an absolute pressure of between 0.35 bar and 0.7 bar and it is compressed to an absolute pressure of between 2 bar and 6 bar, advantageously at a pressure of approximately 3 bar, by the first compression member 120. This gas at an absolute pressure of approximately 3 bar then borrows the first conduct 128 along which it undergoes a derenre operated by the pressure regulating means 182, ie its pressure is reduced to a pressure equal to or substantially equal to 1 bar. The gas is then compressed by the second compression member 130 to a pressure compatible with the needs of the gas consuming device 300, for example a pressure between 5 bar and 20 bar or greater than 150 bar, depending on the consuming device. of gas 300 is a consumer dir low pressure or high pressure.

FIG. 10 illustrates for its part a third mode of operation of the second exemplary embodiment in which at least one gas consuming device 300 is supplied by gas taken in the liquid state in the tank 200, evaporated by the exchanger 110 and compressed by the first compression member 120, and also by gas taken in the gaseous state in the top 201 of the tank 200 and compressed by the second compression member 130. Thus, as illustrated, according to In this third mode of operation, the pressure regulating means 182 and the first flow regulating means 183 are in their closed positions while the second flow regulating means 184 is in its open position. The gas taken in the gaseous state in the head 201 of the tank 200 thus passes into the first heat exchanger 410 in which it does not undergo any significant change in temperature or pressure before being compressed to the pressure compatible with the need of the gas consuming device 300 by the second compression member 130 then it is sent to this gas consuming device 300. The gas taken in the liquid state in the tank 200 is evaporated through the exchange of heat which takes place in the heat exchanger 110 then it is compressed to the pressure compatible with the needs of the gas consuming device 300 by the first compression member 120 in order to then be able to supply this consuming device. gas 300. Thus, according to this second exemplary embodiment, the first compression member 120 is configured to compress the gas issuing from the heat exchanger 110 with a pressure of between 0.35 bar and 0.7 bar up to a press ion between 5 bar and 20 bar, or greater than 150 bar depending on the gas consuming device to be supplied and the second compression member 130 esr configured to compress the gas taken in the gaseous state in the air 201 of the tank 200 from a pressure approximately equal to 1 bar up to a pressure between 5 bar and 20 bar or greater than 150 bar depending on the gas consuming device to be supplied.

Similarly to what has been described above with reference to FIGS. 5 and 6, the power supply system 100 according to the second exemplary embodiment provides for redundancy of the compression members 120, 130 in order to ensure, on the one hand, a continuous supply of the gas consuming device 300 and, on the other hand, a maintenance of the pressure in the tank 200 at an acceptable value for this tank 200.

Figures 11 and 12 illustrate this redundancy of the compression members 120, 130.

FIG. 11 illustrates the gas supply system 100 according to the second embodiment of the present invention in which the first compression member 120 has failed. As shown, in the event of failure of the first compression member 120, the supply of the gas consuming device 300 with gas taken in the gaseous state from the top 201 of the tank 200 is provided by the second compression member 130, the pressure regulating means 182, the first flow regulating means 183 and the second flow regulating means 184 being all three in their closed position, i.e. preventing the flow of gas, respectively, in the first conduit 128, in the second conduit 129 and in the fifth conduit 105. In this situation, this FIG. 9 illustrates a mode identical to the first operating mode of the system 100 illustrated in FIG. 8 and reference may be made to the description do above with reference to this figure 8.

FIG. 12 illustrates the gas supply system 100 of at least one gas consuming appliance 300 according to the second exemplary embodiment of the present invention in which the second compression member 130 fails. In this situation, the pressure regulating means 182 is put in its closed position, so that no gas circulates in the first duct 128, the first flow regulating means 183 is put in its open position and the second means flow control valve 184 is also placed in its open position. Thus, the gas taken in the gaseous state in the air 201 of the tank 200 borrows the second lead 129 to join the first compression member 120 configured to compress the gas to the pressure compatible with the needs of the gas consuming appliance 300. The gas thus compressed then takes the fifth conduit 105 and the sixth conduit 106 to reach the appliance gas consumer 300. The second pump 141 is for its part stopped so that no heat exchange takes place in the heat exchanger 110.

Thus, the system 100 according to the second exemplary embodiment makes it possible to ensure the supply of the gas consuming device 300 with gas taken in the gaseous state in the head 201 of the tank 200, thus ensuring the maintenance of the gas. pressure in the tank 200 to an acceptable value for this tank 200 under the circumstances, and in particular in the event of failure of the first compression member 120 or of the second compression member 130.

FIGS. 13 and 14 illustrate a fourth mode of operation and a fifth mode of operation of the system 100 according to the second exemplary embodiment of the present invention.

FIG. 13 thus illustrates the fourth operating mode of the system 100. According to this fourth operating mode, the first flow regulation means 183 carried by the second conduit 129 is a pressure regulating member. This fourth operating mode corresponds to an operating mode in which the quantity of gas taken in the gaseous state in the top 201 of the tank 200 is insufficient to correctly supply the at least one gas consuming device 300. The first pump 140 is therefore put into operation so as to allow the supply of at least one gas consuming device 300 with gas evaporated by the heat exchanger 110. In addition, according to this fourth mode of operation, the circulation of gas in the seventh pipe 107 is interrupted - for example by means of a turn-or-nothing valve not shown here - so that the gas taken in the gaseous state in the head 201 of the tank 200 is directed towards the second pipe 129 along from which it undergoes an expansion operated by the first flow regulating means 183. The gas sampled at a pressure of approximately 1 bar absolute is thus expanded to a pressure between 0.35 bar and 0.7 bar in order to be able to wander mixed with the gas taken in the liquid state in the tank 200 and evaporated by the heat exchanger 110, then to be compressed by the first compression member 120 and finally to be used to supply the gas consuming apparatus 300. In other words, this fourth operating mode advantageously makes it possible to supply the first compression member 120 with gas taken in the liquid state from the tank 200 and evaporated. by the heat exchanger 110 and in gas taken in the gaseous state in the top 201 of the tank 200 by the same inlet 125 of this first compression member 120.

FIG. 14 illustrates for its part the fifth mode of operation of the system 100 according to the second exemplary embodiment. According to this fifth mode of operation illustrated, the system 100 is configured to supply two gas consuming appliances 300, 301, a first gas consuming appliance 300 being configured to be supplied with gas at a first pressure and a second gas consuming appliance. 301 being configured to be supplied with gas at a second pressure, the second pressure being lower than the first pressure.

According to this fifth mode of operation, a tenth duct 190 extends between the second flow regulating means 184 and the second gas consuming device 301, so that the first compression member 120 and the second compression member 130 are after in supplying, in parallel and independently of each other, the first gas consuming device 300 and the second gas consuming device 301. An eleventh conduit 191 is further arranged between this tenth conduit 190 and the sixth conduit 106 connected to the first gas-consuming device 300, this eleventh pipe 191 carrying a pressure regulator 192.

This fifth operating mode illustrated in FIG. 14 corresponds to an operating mode in which the quantity of gas present in the gaseous state in the head 201 of the tank 200 is insufficient to correctly supply the gas consuming devices 300, 301, so that the first pump 140 is put into operation and supplies the heat exchanger 110. In a similar way to what has been described above, the gas taken in the liquid state in the tank 200 is thus evaporated by its passage through the heat exchanger 110 and can then participate in the supply of gas consuming devices 300, 301. Thus, according to this fifth mode of operation, the first compression member 120 is configured to compress the gas withdrawn from it. 'liquid state in the tank 200 and evaporated by its passage through the heat exchanger 110 at an absolute pressure between 0.35 bar and 0.7 bar up to a pressure between 2 bar and 6 bar, this is that is to say a pressure corresponding to the supply pressure of the second gas consuming device 301. The second compression member 130 is for its part configured to compress the gas withdrawn in the gaseous state in the head 201 of the tank 200 from a pressure of about 1 bar absolute up to a pressure between 5 bar and 20 bar, which corresponds to the supply pressure of the first gas consuming device 300. Optionally, the pressure regulator 192 carried by the eleventh conduit 19 1 can be put in an open position, thus allowing the passage of gas compressed by the second compression member 130 in this eleventh conduit 191. The gas from this second compression member 130 is thus expanded so as to be able to supply the second device. gas consumer 301 if necessary.

FIG. 14 more particularly illustrates a situation in which the quantity of gas withdrawn in the liquid state and evaporated by the heat exchanger 110 is greater than the quantity of gas necessary for the supply of the second gas consuming device 301. In in this case, the pressure regulating means 182 carried by the first pipe 128 is placed in its open position so as to allow the passage of the gas compressed by the first compression member 120 in this first pipe 128. As mentioned above, the regulating means 182 is configured to reduce the pressure of the gas passing through it. Thus, the gas leaves the first compression member 120 at a pressure of between 2 bar and 6 bar undergoes an expansion operated by the regulating means 182 to a pressure of approximately 1 bar, and can thus be mixed with the gas sampled. in the gaseous state in the top 201 of the tank 200 to be compressed by the second compression member 130 to a pressure of between 5 bar and 20 bar in order to then be able to supply the first gas consuming device 300. The description of the redundancy systems provided in the event of failure of the first compression member 120 or of the second compression member 130 given previously with reference to FIGS. 11 and 12 applies mutatis mutandis to these fourth and fifth operating modes.

Finally, FIG. 15 is a cut-away view of a ship 70 which shows the tank 200 which conrienr the natural gas in the liquid state and in the gaseous state, this tank 200 being of generally prismatic shape mounted in a double hull 72 of the ship. This tank 200 can be part of an LNG carrier but it can also be a tank when the gas is used as fuel for the gas consuming device.

The wall of the tank 200 comprises a primary sealing membrane intended to wander in contact with the gas in the liquid state contained in the tank, a secondary sealing membrane arranged between the primary sealing membrane and the double shell 72 of the ship 70, and two insulating barriers arranged respectively between the primary waterproofing membrane and the secondary waterproofing membrane and between the secondary waterproofing membrane and the double hull 72.

Loading and / or unloading lines 73 arranged on the upper deck of the vessel can be connected, by means of suitable connectors, to a marine or port terminal to transfer the cargo of natural gas in the liquid state from or to the tank. 200.

FIG. 15 also shows an example of a marine terminal comprising a loading and / or unloading station 75, an underwater conduit 76 and an onshore installation 77. The loading and / or unloading station 75 is a fixed off-site installation. -shore comprising a movable arm 74 and a tower 78 which supports the movable arm 74. The movable arm 74 carries a bundle of isolated pipes 79 which can be connected to the loading and / or unloading pipes 73. The movable arm 74 can be steered. adapts to all ship sizes. The loading and unloading station 75 allows the loading and / or unloading of the ship 70 from or to the onshore installation 77. The latter comprises liquefied gas storage tanks 80 and connecting pipes 81 connected by the drive submarine 76 to the post of loading or unloading 75. The submarine conduit 76 allows the transfer of the liquefied gas between the loading or unloading station 75 and the onshore installation 77 over a great distance, for example five km, which makes it possible to keep the ship 70 at a great distance from the coast during loading and / or unloading operations. To generate the pressure necessary to transfer the liquefied gas, one or more unloading pumps carried by the loading and / or unloading tower of the tank 200 and / or the pumps equipping the onshore installation 77 and / or or pumps fitted to the loading and unloading station 75.

Of course, the invention is not limited to the examples which have just been described and many modifications can be made to these examples without departing from the scope of the invention.

The present invention thus proposes a gas supply system for at least one gas consuming device which makes it possible to supply gas consuming devices present on a ship while maintaining a pressure in the tank fitted to this ship. and containing the gas, at an acceptable value for this tank in all circumstances and, advantageously, at a limited cost since it only requires two compression members.

The present invention cannot however be limited to the means and configurations described and illustrated here and it also extends to any equivalent means and any configuration as well as to any technically operative combination of such means. In particular, the characteristics described with reference to the various exemplary embodiments can be combined insofar as they are not mutually incompatible.

Claims

1. Gas supply system (100) of at least one gas consuming device (300) fitted to a ship (70), the supply system (100) comprising at least:

- a gas supply line (123) of at least one gas consuming device (300) configured to be traversed by gas taken in the liquid state in a tank (200) and subjected to a pressure lower than a gas pressure in a head (201) of the tank (200),

- a first compression member (120) configured to compress the gas from the gas supply line (123) to at least one gas consuming device (300),

- a second compression member (130), characterized in that the first compression member (120) and the second compression member (130) alternately compress gas in the gaseous state coming from the supply line (123) gas and gas taken in the gaseous state in the head (201) of the tank (200).

2. A gas supply system (100) according to the preceding claim, comprising at least one heat exchanger (110) configured to perform a heat exchange between the gas which circulates in the supply line (123) and gas. taken in the liquid state from the tank (200).

3. Gas supply system (100) according to the preceding claim, wherein the heat exchanger (110) is equipped with at least one first pass (111) configured to be supplied with the gas taken from the state. liquid in the vessel (200) of the vessel (70) and at least one second pass (112) configured to be supplied by the gas subjected to a pressure lower than the pressure of the gas in the head (201) of the vessel (200) ,

4. System (100) according to the preceding claim, comprising at least a first pump (140) configured to supply the first pass (111) of the heat exchanger (110), a second pump (141) configured to supply the second. pass (112) of the heat exchanger (110), at least one expansion means (170) being arranged on the supply line (123), between the second pump (141) and the second pass (112) of the heat exchanger (110).

5. System (100) according to any one of the preceding claims, wherein the first compression member (120) and the second compression member (130) suck the gas taken from the head (201) of the tank (200). .

6. System (100) according to any one of the preceding claims, comprising as a compression member only the first compression member (120) and the second compression member (130).

7. System (100) according to any one of the preceding claims, comprising at least one reliquefaction system (400) of the gas compressed by the first compression member (120) and / or by the second compression member (130).

8. System (100) according to the preceding claim, wherein the reliquefaction system (400) comprises at least a first heat exchanger (410) equipped with at least a first pass (411) configured to be traversed by gas compressed by the first compression member (120) and / or by the second compression member (130) and at least one second pass (412) configured to be traversed by gas taken in the gaseous state in the air (201) of the tank (200).

9. System (100) according to the preceding claim, wherein the reliquefaction system (400) comprises at least a second heat exchanger (420) configured to operate a heat exchange between the compressed gas which leaves the first pass (411) of the heat exchanger. first heat exchanger (410) and gas taken in liquid state from the tank (200).

10. System (100) according to any preceding claim, wherein the first compression member (120) is configured to be supplied with gas having a pressure between 0.35 and 0.7 bar and to compress this. gas up to a pressure between 2 bar and 13 bar and in which the second compression member (130) is configured to be supplied with gas having a pressure equivalent to 1 bar and to compress it to a pressure between 5 bar and 20 bar.

11. System (100) according to any one of the preceding claims, wherein at least one pipe (119) is arranged between the top (201) of the tank (200) and an intermediate inlet (122) of the first compression member (120), at least one regulating member (181) being arranged on this at least one pipe (119).

12. System (100) according to any one of claims 1 to 10, wherein the first compression member (120) and the second compression member (130) are mounted in series with respect to each other.

13. System (100) according to the preceding claim, wherein at least a first pipe (128) is arranged between an outlet (124) of the first compression member (120) and an inlet (131) of the second compression member (130). ), at least one pressure regulating means (182) being arranged on this at least one first pipe (128).

14. System (100) according to the preceding claim, wherein at least a second pipe (129) is arranged between an outlet of the second pass (412) of the first heat exchanger (410) and an inlet (125) of the first member of compression (120), at least one first flow rate regulating means (183) being arranged on this at least one second pipe (129).

15. System (100) according to any one of claims 12 to 14, wherein the first compression member (120) is configured to be supplied with gas having a pressure between 0.35 bar and 0.7 bar and to compress it to a pressure between 2 bar and 6 bar, and in which the second compression member (130) is configured to be supplied with gas having a pressure equivalent, or substantially equivalent, to 1 bar and for the compress to a pressure between 5 bar and 20 bar.

16. Liquefied gas transport vessel (70), comprising at least one tank (200) of a liquefied gas cargo, at least one appliance consuming evaporated gas (300) and at least one supply system (100). gas from the at least one gas consuming apparatus (300) according to any preceding claim.

17. A vessel (70) according to the preceding claim, comprising at least a first gas consuming apparatus (300) configured to be supplied with compressed gas at a first pressure, and at least a second gas consuming apparatus (301) configured to be supplied with gas. be supplied with compressed gas at a second pressure, the first gas consuming apparatus (300) and the second gas consuming apparatus (301) being both configured to be supplied by the at least one supply system (100), and the first supply pressure of the first gas consuming apparatus. gas (300) being greater than the second supply pressure of the second gas consuming apparatus (301).

18. A system (100) for charging or discharging a gas in the liquid state which combines at least one means on land and at least one vessel (70) for transporting gas in the liquid state according to the preceding claim.

19. A method of loading or unloading a gas in the liquid state from a gas transport vessel (70) according to claim 16.