JP2019522758A - Equipment for feeding flammable gas to gas consuming members and for liquefying this flammable gas - Google Patents

Abstract

The present invention relates to an installation (1) for feeding flammable gas to a gas consuming member (2, 3, 4) and liquefying the flammable gas, the installation comprising: a leak-proof and insulated tank (5a) 5b, 5c, 5d), a gas phase gas collection circuit (6) for removing a combustible gas stream from the tank, and a first channel (9) connected to the gas phase gas collection circuit , A heat exchanger (8), connected to the first channel of the heat exchanger, transporting combustible gas to the gas consuming member, and combustible gas to the second channel (10 of the heat exchanger Connected to a second channel of the heat exchanger (8) via an intermediate circuit (15) and a compressor (11) connected to a three-way connector (12, 13) that can be transported to Expansion device (14) and liquid phase combustible gas withdrawn from the tank When, is arranged to transfer heat between the combustible gas stream to be cooled, and a cooling device (16).

Description

TECHNICAL FIELD The present invention relates to the field of equipment for treating flammable gases such as liquefied natural gas (LNG).

  More specifically, the present invention is directed to equipment for feeding combustible gas to a gas consuming member on the one hand and liquefying the combustible gas on the other hand.

Technical background Liquefied natural gas is stored in leak-proof and insulated tanks in a liquid / gas two-phase equilibrium at cryogenic temperatures. The insulation barrier of a liquefied natural gas storage tank is a site of heat flow that tends to heat the contents of the tank, which is reflected by the evaporation of liquefied natural gas. Gas from natural evaporation is generally used to power the gas consuming member to improve it. Thus, for example, in a methane tanker, the vaporized gas is used to power a generator that supplies the electricity required for the function of the powertrain or onboard equipment to propel the ship. However, such practice makes it possible to improve the gas originating from spontaneous evaporation in the tank, but this does not make it possible to reduce the amount.

  Thus, the prior art, in particular US Pat. No. 2015/0 316 208, improves part of the gas derived from natural evaporation via one or more gas consuming members, and separates the gas derived from natural evaporation. A facility that can both allow liquefaction of the part. Such equipment comprises a collection circuit that draws gas phase gas in the gaseous headspace of the tank and then transports it to a heat exchanger to be heated therein. Upon leaving the exchanger, the heated gas stream is compressed to a high pressure compatible with the operating conditions of the gas consuming member. Thereafter, the first portion of compressed gas is conveyed to one or more gas phase gas consuming members to be burned therein, while the second portion of compressed gas is transferred to the tank Is returned to the exchanger to transfer heat to the gas phase gas stream collected in the gaseous headspace. The second portion of the gas so cooled and partially liquefied is then depressurized in the expansion device, and using the Joule-Thompson effect, the temperature of the gas stream is at least partially reliquefied. To further decrease during its expansion. Upon leaving the expansion device, the phase separator delivers the liquid phase and gas phase so that the liquid phase is transported into the tank and the gas phase is returned to the gas phase gas collection circuit upstream of the heat exchanger. Allows to be separated before doing.

  Such an arrangement allows both compression of the gas stream to both match one part of the gas stream with the working conditions of the gas consuming member and allow subsequent reliquefaction of the other part of the gas stream. It is particularly advantageous in that it is used. Thus, the equipment is thereby simplified and the cost of the additional reliquefaction function is limited.

  However, this type of equipment is not completely satisfactory. In particular, under certain critical operating conditions, for example when the tank is only partially filled, the reliquefaction yield is low. Specifically, when the tank is only partially filled, the temperature of the vapor present in the gaseous headspace of the tank tends to rise very much above the gas equilibrium temperature. Thus, the exchange of heat between the gas stream collected in the tank and the second part of the compressed gas to be liquefied is to reliquefy a large proportion of the second part of the compressed gas. There is a risk of being insufficient.

  Further, gas phase natural gas derived from natural evaporation has a composition of volatile components such as nitrogen that is more abundant than liquefied natural gas in a liquid state stored in a tank. Thus, for a liquefied natural gas cargo with 0.5% molar nitrogen, the gas derived from natural evaporation tends to have a nitrogen concentration of about 14-15%. Furthermore, the use of an expansion device that uses Joule-Thompson expansion and whose gas phase is returned to the gas phase gas collection circuit at its outlet leads to the nitrogen being concentrated in the gas stream being processed by the facility. Thus, some of the compressed gas delivered to one or more gas consuming members tends to have a nitrogen concentration much higher than 20%. Here, the high concentration of nitrogen leads to incomplete combustion of the gas in the gas consuming member and operational defects of the gas consuming member.

US Patent Application Publication No. 2015/0316208

The idea that forms the basis of the present invention is to deliver a combustible gas to a gas consuming member, which makes it possible to obtain an increased combustible gas liquefaction yield, at least under certain critical operating conditions, It is to propose equipment for liquefying combustible gas.
According to one embodiment, the present invention provides equipment for feeding a combustible gas to a gas consuming member and liquefying the combustible gas,
A leak-proof and insulated tank comprising an inner space intended to be filled with a combustible gas in a liquid-gas two-phase equilibrium;
A gas phase gas collection circuit comprising an inlet that emerges in the inner space of the tank and is arranged to extract a gas phase combustible gas stream from the inner space of the tank;
A first and second channel and a heat exchange wall for transferring heat from the second channel to the first channel, wherein the first channel and the second channel are respectively an inlet and an outlet; A heat exchanger, wherein the inlet of the first channel is connected to a gas phase gas collection circuit to heat the gas phase combustible gas stream in the heat exchanger; and ,
-Connected upstream to the outlet of the first channel of the heat exchanger so as to compress the heated combustible gas in the heat exchanger, carrying the first part of the combustible gas stream to the gas consuming member; Connected downstream to a three-way connector capable of transporting the second part of the combustible gas stream to the inlet of the second channel of the heat exchanger to cool the second part of the combustible gas , The compressor,

An expansion device connected upstream to the outlet of the second channel of the heat exchanger via an intermediate circuit and connected downstream to a return circuit leading to the tank, wherein the combustible gas stream originating from the intermediate circuit An expansion device arranged to depressurize the second part,
The installation also comprises a cooling device comprising an extraction circuit, which is arranged to emerge in the inner space of the tank and extract a liquid phase combustible gas stream in the inner space of the tank. The cooling device comprises an inlet and evaporates the liquid phase combustible gas stream withdrawn from the tank and uses the latent heat of evaporation of the liquid phase combustible gas stream withdrawn from the tank and is combustible to be cooled A second of the liquid phase combustible gas stream withdrawn from the tank, the gas phase combustible gas stream circulating in the gas phase gas collecting circuit and the combustible gas stream circulating in the intermediate circuit so as to cool the gas stream; It should be noted that it is arranged to transfer heat to and from the combustible gas stream to be cooled.

  Thus, the present invention proposes to use the liquid phase of combustible gas stored in the tank and still further reduce the temperature of the compressed gas at the inlet of the expansion device, the temperature reduction being intermediate The first part of the heat exchanger so that the temperature at the outlet of the second channel of the exchanger acts directly on the second part of the compressed gas stream circulating in the circuit or is consequently reduced. It can be obtained either by reducing the temperature of the gas at the inlet of the channel. Thus, by reducing the temperature of the gas stream at the inlet of the expansion device, its degree of liquefaction during its decompression within the expansion device is substantially increased. This is to obtain an increased reliquefaction yield under certain critical operating conditions, especially when the temperature of the vapor present in the gaseous headspace of the tank is very much above the equilibrium temperature of the gas. Enable.

  In addition, when the combustible gas is a gaseous mixture of LNG or LPG type containing a small percentage of nitrogen and the cooling device is arranged to carry the vaporized gas stream within the gas phase gas collection circuit , Such an installation is designed to pass a nitrogen stream in a gas stream that is intended to be passed through the gas consuming member so as to adapt it to the operating conditions of the gas consuming member without substantially degrading the reliquefaction yield. Makes it possible to carry out dilutions of

  According to embodiments, such an installation may comprise one or more of the following characteristics:

  According to one embodiment, the combustible gas is a gaseous mixture of LNG or LPG type comprising nitrogen.

  According to one embodiment, the combustible gas is a gaseous mixture containing nitrogen, and nitrogen is the most volatile component of the gaseous mixture.

  According to one embodiment, the cooling device carries the vaporized gas stream in the cooling device to the gas phase gas collection circuit so as to reduce the nitrogen content of the combustible gas stream circulating in the gas phase gas collection circuit. Arranged.

  Thus, when the combustible gas is composed of a gaseous mixture containing nitrogen, the vaporized gas stream in the cooling device is withdrawn in the liquid phase from the tank with the most volatile compounds such as reduced concentration of nitrogen. This leads to a reduction of the nitrogen concentration in the gas phase that is processed in the facility because it is derived from the directed gas stream. This consequently makes it possible to keep the nitrogen concentration in the gas processed by the installation within a range compatible with the correct functioning of the gas consuming member. In addition, the lower the gas phase gas at the entrance of the facility having a composition rich in volatile components, the greater the liquefaction yield. As a result, by mixing the vaporized gas stream in the cooling device with the gas stream derived from natural evaporation, the nitrogen concentration of the resulting mixture is reduced, which is the degree of liquefaction during decompression in the expansion device. Makes it possible to increase

  According to a first embodiment, the cooling device comprises first and second channels and a heat exchange wall for transferring heat from the first channel to the second channel of the additional heat exchanger. Comprising an additional heat exchanger, the first channel and the second channel each comprising an inlet and an outlet, the first channel being integrated into an intermediate circuit connecting the heat exchanger and the expansion device; The inlet of the second channel is connected to the inlet of the cooling device, and the outlet of the second channel is connected to the gas phase gas collection circuit.

  According to a first embodiment variant, the additional heat exchanger is superimposed above the heat exchanger and the outlet of the second channel of the additional heat exchanger is at the inlet of the first channel of the heat exchanger. Connected, and thus the liquid phase gas stream can flow by gravity from the outlet of the second channel of the additional heat exchanger to the inlet of the first channel of the heat exchanger.

  According to a second embodiment variant, the cooling device comprises a first channel integrated in the gas phase gas collection circuit, an inlet connected to the extraction circuit and an outlet connected to the gas phase gas collection circuit. And a second additional heat exchanger.

  According to a second embodiment, the cooling device comprises a chamber integrated into the gas phase gas collection circuit between the inlet of the gas phase gas collection circuit and the inlet of the first channel of the heat exchanger; A liquid phase combustible gas connected to an extraction circuit to cool the gas phase gas stream extracted from the interior space of the tank and reduce the nitrogen content of the combustible gas stream circulating in the gas phase gas collection circuit And a spray member arranged to spray into the chamber.

  According to a variation of any of the three above-mentioned embodiments, the cooling device may draw a liquid phase combustible gas stream through the inlet of the cooling device and deliver it into the extraction circuit. A pumping device is provided.

  According to one embodiment, the installation comprises a gas analyzer that can deliver a representative measurement of the nitrogen concentration in the first portion of the combustible gas stream, and the control unit is below the critical operating concentration of the gas consuming member. To the pumping device as a function of a representative measurement of the nitrogen concentration in the first part of the combustible gas stream delivered to the gas consuming member to ensure the nitrogen concentration in the first part of the combustible gas stream Arranged to generate control signals.

  According to one embodiment, the gas analyzer can analyze the composition of the gas sample so as to infer its nitrogen concentration. According to another embodiment, the gas analyzer is a machine for measuring the higher heating value of a gas sample.

According to one embodiment variant, the control unit is configured to provide a representative measurement of nitrogen concentration and gas in the first part of the combustible gas stream so as to keep the nitrogen concentration in the first part of the combustible gas stream to a nominal concentration. Arranged to generate a control signal for the pumping device as a function of the nominal concentration below the limit operating concentration of the consumable member.
According to another embodiment variant, the control unit comprises:

  -This is below the representative measurement of the nitrogen concentration in the first part of the combustible gas stream and the critical operating concentration of the gas consuming member so that the nitrogen concentration in the first part of the combustible gas stream is kept to the nominal concentration A nitrogen concentration priority mode that generates a control signal for the pumping device as a function of the nominal concentration; and

This generates a control signal for the pumping device as a function of the temperature measurement T1 and the nominal temperature of the second part of the gas stream circulating in the intermediate circuit at the inlet of the expansion device, so as to keep the temperature T1 at the nominal temperature. Re-liquefaction priority mode,
The control unit is arranged to switch from the nitrogen concentration priority mode to the reliquefaction priority mode as a function of a representative measurement of nitrogen concentration in the first portion of the combustible gas stream.

  According to one embodiment, the cooling device comprises a sensor capable of measuring the temperature T1 of the second part of the gas stream circulating in the intermediate circuit at the inlet of the expansion device, and in at least one operating mode, the temperature T1 And a control unit arranged to generate a control signal for the pumping device as a function of the measured value of temperature T1 and the nominal temperature.

  According to a first variant, the pumping device comprises a pump and the control unit is arranged to steer the pump as a function of the control signal. In other words, the liquid phase gas flow rate delivered by the pump of the pumping device is varied to obtain the desired flow rate.

  According to a second variant, the pumping device is connected to the pump, firstly to the extraction circuit downstream of the pump, and secondly to the return space inside the tank and to the return pipeline connector respectively. And a control unit arranged to steer one and / or the other of the two valves as a function of the control signal. The In other words, the pump of the pumping device operates at constant power, and one and the other of the two valves has a portion of the liquid phase gas stream carried into the extraction circuit to be evaporated and a return pipeline Is operated to correct the distribution between the portion of the liquid-phase gas flow returning to the tank via the.

  According to one embodiment, the expansion device is an expansion valve, also known as a Joule Thomson valve.

  According to one embodiment, the installation is connected upstream to the expansion device, on the one hand to a return circuit leading to the tank and on the other hand downstream to a return pipe connected to the gas phase gas collection circuit. With a separator, the phase separator is arranged to carry the liquid phase of the combustible gas stream to the return circuit and to carry the gas phase of the combustible gas stream to the return pipe.

  According to an advantageous variant, the compressor is a multistage compressor. Advantageously, the compressor comprises a plurality of compression stages and a plurality of intermediate heat exchangers, each intermediate heat exchanger being arranged at the outlet of one of the compression stages.

According to one embodiment, the present invention also provides a process for feeding a combustible gas to a gas consuming member and liquefying the combustible gas using the equipment referred to above. ,
Conveying a gas phase combustible gas stream from the inlet of the gas phase gas collection circuit to the inlet of the first channel of the heat exchanger;
Transferring heat from the second channel of the heat exchanger to the first channel;
-Compressing the combustible gas stream exiting the first channel of the heat exchanger;
Conveying a first part of the compressed combustible gas stream to the gas consuming member and conveying a second part of the compressed gas stream to the inlet of the second channel of the heat exchanger;
Conveying a second part of the combustible gas stream from the second channel of the heat exchanger via an intermediate circuit to the expansion device;
-Depressurizing the second portion of the combustible gas stream originating from the intermediate circuit;
Transporting at least a portion of the liquid phase portion of the second portion of the decompressed combustible gas stream to the tank;
-Withdrawing a liquid phase combustible gas stream from the inner space of the tank;
-Evaporate the liquid flammable gas stream withdrawn from the tank and use the latent heat of evaporation of the liquid phase flammable gas stream withdrawn from the tank to remove from the tank to cool the gas stream to be cooled. And a gas stream to be cooled selected from a second part of the gas phase gas stream circulating in the gas phase gas collection circuit and the gas stream circulating in the intermediate circuit. Transferring heat between them.

  According to one embodiment, the combustible gas is a gaseous mixture comprising nitrogen and the vaporized gas stream in the cooling device is conveyed to a gas phase gas collection circuit.

  According to one embodiment, a variable representing the nitrogen concentration in the first portion of the combustible gas stream is measured and the flow rate of the liquid phase combustible gas stream circulating in the extraction circuit of the cooling device is determined by the flow rate of the combustible gas stream: Adjusted as a function of a variable representing the nitrogen concentration in the first part.

  According to an embodiment variant, the flow rate of the liquid phase combustible gas stream circulating in the extraction circuit of the cooling device is such that the nitrogen concentration in the first part of the combustible gas stream is kept at a nominal concentration so that the combustible gas stream Adjusted as a function of a variable representing the nitrogen concentration in the first part and the nominal concentration.

  According to one embodiment, in at least one mode of operation, the temperature T1 of the second part of the gas stream circulating in the intermediate circuit upstream of the expansion device is measured and the liquid phase circulating in the extraction circuit of the cooling device. The flow rate of the combustible gas stream is adjusted as a function of the measured value of the temperature T1 and the nominal temperature so as to keep the temperature T1 at the nominal temperature.

  According to an advantageous variant, the combustible gas is liquefied natural gas and the nominal temperature T1 is from −145 to −160 ° C.

  According to one embodiment, the present invention provides a ship comprising the equipment mentioned above.

  According to one embodiment, the present invention may also be loaded in such ships where flammable gases are passed through cryogenic transfer pipes, from floating or terrestrial storage facilities, or to, or from the tanks of ships. Provide a process for discharging.

  According to one embodiment, the present invention also provides a system for transporting flammable gas, the system floating or onshore storage the vessel referred to above and a tank installed in the ship's hull. A cryogenic transfer pipe arranged to connect to the facility, and a pump for driving a combustible gas stream from or to a floating or shore storage facility, or to a ship's tank, through the cryogenic transfer pipe; Is provided.

  The invention will be better understood and further objectives, details will be understood from the following description of some specific embodiments of the invention, given by way of illustration and not limitation, with reference to the accompanying drawings, in which: , Properties, and their advantages become clearer.

FIG. 1 is a schematic illustration of equipment for feeding a combustible gas to a gas consuming member and liquefying the combustible gas according to the first embodiment.

FIG. 2 is a schematic illustration of an installation according to a second embodiment.

FIG. 3 is a schematic illustration of an installation according to a third embodiment.

FIG. 4 illustrates in a detailed manner the arrangement of the two heat exchangers of FIG. 2 according to one embodiment variant.

FIG. 5 illustrates the apparatus of FIG. 2 as a function of the nitrogen concentration in the natural gas in the liquid state when 70% of the flow of the combustible gas stream is returned to the heat exchanger for reliquefaction therein. 2 is a graph illustrating the nitrogen concentration of different natural gas streams.

FIG. 6 is a graph similar to that of FIG. 5 when 70% of the flow of combustible gas stream is returned to the heat exchanger for reliquefaction therein.

FIG. 7 shows the flow rate of the reliquefied gas as a function of the flow rate of the second part of the combustible gas stream returning to the inlet of the second channel of the heat exchanger for the installation of FIG. 1 and that of FIG. It is a graph showing the difference between the flow rates of the liquid phase gas extracted from the tank.

FIG. 8 shows a first of the gas flow conveyed to the gas consuming member as a function of the flow rate of the second part of the combustible gas flow returning to the heat exchanger for the prior art installation and the installation according to FIG. 1 or 2. It is a graph showing the nitrogen concentration of a part.

FIG. 9 shows the flow rate of the reliquefied gas and the liquid phase withdrawn from the tank as a function of the flow rate of the second part of the combustible gas stream returning to the heat exchanger for the installation according to the prior art and the installation according to FIG. It is a graph showing the difference between the flow rates of gas.

FIG. 10 is a schematic representation of a transfer system for loading / withdrawing ships and combustible gases.

DETAILED DESCRIPTION OF EMBODIMENTS In the description and claims, the term “flammable gas” has general properties and favors a gas composed of a single pure substance or a gaseous mixture composed of multiple components. Point without.

  In FIG. 1, on the one hand, an installation 1 for delivering flammable gas to one or more gas consuming members and on the other hand for liquefying flammable gas is illustrated. Such an installation 1 can be installed on land or on a floating structure. In the case of a floating structure, the installation 1 can be intended for a liquefaction or regasification barge, or for a liquefied natural gas cargo ship such as a methane tanker, or more generally with any gas consuming member. May be intended for any ship.

  The facility 1 comprises three different types of combustible gas consuming members, namely a burner 2, a generator 3, and an engine 4 for propelling the ship.

  The burner 2 can be integrated into a power production facility or can be integrated into a gas combustion unit (GCU). The power production facility may in particular comprise a steam production boiler. The steam may be intended to power a steam turbine for producing energy and / or power a ship's heating network. The burner 2 can function with a combustible gas whose nitrogen concentration is high, for example over 30% to 35% for a standard gas combustion unit, but can be clearly exceeded by supplying fuel. It is.

  The generator 3 comprises, for example, a diesel / natural gas mixed power supply heat engine of DFDE (Dual Fuel Diesel Electric) technology, for example. Such heat engines can burn a mixture of diesel and natural gas or use one or the other of these two fuels. The natural gas that powers such a heat engine must have a pressure of about a few bar to a few tens bar, for example about 6 to 8 bar absolute. In addition, natural gas must have a nitrogen concentration below the critical operating concentration of about 15% to 20% to allow compliant functioning of such heat engines.

  The engine 4 for propelling the ship is, for example, a dual fuel two-stroke low-speed engine of “ME-GI” technology developed by the company MAN. Such an engine 4 uses natural gas as a combustible and a small amount of pilot fuel that is injected before the natural gas is injected to ignite it. In order to power such an engine 4, the natural gas must first be compressed at a high pressure of 150 to 400 bar absolute, more specifically 250 to 300 bar absolute. In addition, such engines are extremely sensitive to the quality of natural gas, and natural gas has a nitrogen concentration that does not exceed a threshold of about 15% to 20% to allow compliant functions. Must be.

  The installation 1 comprises one or more leak-proof and insulation tanks 5a, 5b, 5c, 5d. According to one embodiment, each tank 5a, 5b, 5c, 5d is a membrane tank. By way of example, such membrane tanks are described in patent applications WO 140/57221, FR 2 691 520, and FR 2 877 638. Such a membrane tank is intended to store flammable gases at a pressure substantially equal to or slightly higher than atmospheric pressure. According to other alternative embodiments, each tank 5a, 5b, 5c, 5d may also be a free-standing tank, and in particular may have a parallelepiped, prism, sphere, cylinder, or multi-lobe shape. One type of tank 5a, 5b, 5c, 5d allows gas storage at a pressure substantially higher than atmospheric pressure.

  Each tank 5a, 5b, 5c, 5d comprises an inner space that is intended to be filled with a combustible gas. Combustible gases in particular include liquefied natural gas (LNG), i.e. mainly containing methane, and also in a small proportion of ethane, propane, n-butane, i-butane, n-pentane, i-pentane, neopentane, And a gaseous mixture comprising one or more other hydrocarbons such as nitrogen. The combustible gas may also be a mixture of hydrocarbons derived from petroleum refining, including ethane or liquefied petroleum gas (LPG), ie essentially propane and butane and a small proportion of nitrogen.

  The combustible gas is stored in the inner space of each tank 5a, 5b, 5c, 5d in a liquid-gas two-phase equilibrium state. The gas is therefore present in the gas phase in the upper part of the tanks 5a, 5b, 5c, 5d and in the liquid phase in the lower part of the tanks 5a, 5b, 5c, 5d. The equilibrium temperature of the liquefied natural gas corresponding to its liquid-gas two-phase equilibrium state is about −162 ° C. when it is stored at atmospheric pressure.

  The equipment 1 comprises a gas phase gas collection circuit comprising suction ports 7a, 7b, 7c, 7d that appear in the respective gaseous headspaces of the tanks 5a, 5b, 5c, 5d, ie above the maximum filling height of the tanks. 6 is provided. These suction ports 7 a, 7 b, 7 c and 7 d are connected to the gas phase gas collecting circuit 6 through the valve 24.

  The gas phase gas collection circuit 6 is connected to the heat exchanger 8. The heat exchanger 8 has heat for transferring heat from the second channel 10 to the first channel 9 and the first and second channels 9, 10 having inlets 9a, 10a and outlets 9b, 10b, respectively. And an exchange wall. In order to optimize heat exchange, the heat exchanger 8 is a countercurrent exchanger. The inlet 9a on the first channel 9 is connected to the gas phase gas collection circuit 6 so as to heat the gas stream derived from spontaneous evaporation collected in the tanks 5a, 5b, 5c, 5d. The outlet 9b of the first channel 9 is connected to a compressor 11 for compressing the gas flow to a pressure compatible with the operation of the gas consuming member.

  In the embodiment shown, the compressor 11 is a multi-stage compressor. In other words, the compressor 11 includes a plurality of compression stages 11a, 11b, 11c, 11d, and 11e, and intermediate heat exchangers 33a, 33b, and 33c disposed at the respective outlets of the compression stages 11a, 11b, 11c, 11d, and 11e. , 33d. The intermediate heat exchangers 33a, 33b, 33c, 33d are intended to cool the compressed gas between the two compression stages 11a, 11b, 11c, 11d, 11e. As an example, the heat exchangers 33a, 33b, 33c, 33d provide in particular an exchange with seawater and thus make it possible to bring the compressed gas stream to a temperature substantially equal to that of seawater. obtain.

  The compressor 27 is dimensioned as a function of the combustible gas consuming member intended to be delivered, in particular as a function of its maximum delivery speed and pressure level at which the combustible gas must be distributed. Thus, when one of the gas consuming members is a ME-GI type engine 4 as described above, the compressor 11 will cause the gas flow leaving the compressor 11 to be typically 250-300 bar. Sized to have absolute value of pressure.

  Downstream of the compressor 11, the installation 1 carries the first part of the gas flow to the engine 4 for propelling the ship, and the second part of the gas flow is the inlet of the second channel 10 of the heat exchanger 8. A three-way connector 12 for carrying to 10a is provided. The three-way connector 12 is steered by a control unit 34. The control unit 34 is therefore in the engine 4 and in the inlet 10a of the second channel 10 of the heat exchanger 8, respectively, as a function of the combustible gas demand of the engine 4 and / or the amount of gas to be reliquefied. It is possible to vary the ratio of the circulating gas.

  Furthermore, if the combustible gas consuming member has different feed pressures as in the embodiment shown, the installation 1 is arranged between the two compression stages 11b, 11c and therefore before the outlet of the compressor 11 An intermediate three-way connector 13 is provided which allows a part of the gas flow to be diverted to the gas consuming member, in this case the burner 2 and the generator 3. Such an arrangement allows the combustible gas to be diverted to the combustible gas consuming member once it has passed through a sufficient number of compression stages 11a, 11b and the delivery pressure corresponding to the consumable member is reached. To do.

  The second part of the gas stream is cooled in the second channel 10 of the heat exchanger 8 during the transfer of its heat to the gas phase gas originating from the gas phase gas collection circuit 6.

  The outlet 10b of the second channel 10 of the heat exchanger 8 is connected to the phase separator 25 via the expansion device 14, through which the combustible gas stream prevails in the tanks 5a, 5b, 5c, 5d. The pressure is reduced to a pressure substantially equal to the pressure, for example, a pressure close to atmospheric pressure. As a result, the gas stream undergoes expansion, which at least partially leads to a decrease in its temperature and its liquefaction via the Joule-Thompson effect. The expansion device 14 is, for example, an expansion valve.

  A phase separator 25, sometimes referred to as a mist separator, allows the liquid phase to be separated from the gas phase. Downstream, the phase separator 25 is connected on the one hand to a return circuit 31 connected to the tanks 5a, 5b, 5c, 5d and on the other hand to a return pipe 32 connected to the gas phase gas extraction circuit 6. The phase separator 25 therefore carries the liquid phase of the combustible gas to the tanks 5 a, 5 b, 5 c, 5 d, while the gas phase is returned to the inlet 9 a of the first channel 9 of the heat exchanger 8.

  The facility 1 also comprises a cooling device 16 for cooling the gas phase gas stream circulating in the gas phase gas collection circuit 6. To do this, the cooling device 16 comprises a chamber 20 that is integrated into the gas phase gas collection circuit 6 and into which the liquid phase combustible gas stream withdrawn from one of the tanks 5c is sprayed. . Thus, the atomized combustible gas stream evaporates and takes heat from the gas phase gas stream collected in the gaseous headspace of the tank. In addition, the spraying and evaporation of a portion of the liquid phase combustible gas, at least in part, is the most volatile component in the gas stream intended to be passed through the gas consuming member 2, 3, 4, in particular Makes it possible to reduce the concentration of nitrogen.

The cooling device 16 includes an extraction circuit 35. The extraction circuit 35 is connected to the tanks 5a, 5b, 5c, 5d at the bottom portion of the tank close to the base of the tank so as to extract the liquid phase of the combustible gas stored in the tank regardless of the filling level. The suction port 27 appears in the inner space of one of these. The cooling device 16 also draws liquid phase combustible gas through the inlet 27 of the cooling device 16 and draws it in the extraction circuit 35 to one or more spray members 21 stored in the chamber 20. A pumping device that can be circulated is provided.
In the embodiment shown, the pumping device is
A pump 26 for aspirating and delivering a liquid phase combustible gas stream;
A return pipeline 37, which on the one hand is connected to an extraction circuit 35 downstream of the pump 26 and on the other hand appears in the inner space of the tank 5c;

  -Comprising two valves 38, 39 respectively installed on the return pipeline 37 and on the extraction circuit 35 downstream of the connection of the return pipeline 37 to the extraction circuit 35;

  The cooling device 16 also comprises a control unit 36 for controlling the pumping device. The control unit 36 is connected to the temperature sensor 29 and the gas analyzer 40. The sensor 29 is arranged in the intermediate circuit 15 and can therefore deliver a temperature measurement T1 of the second part of the compressed gas stream that circulates in the intermediate circuit 15 at the inlet of the expansion device 24. It is. The gas analyzer 40 can deliver a measurement representative of the nitrogen concentration in the gas stream that is intended to be passed through the gas consuming member 2, 3, 4.

  According to one embodiment, the gas analyzer 40 is capable of analyzing the composition of the sample of the gas stream and thus determining the nitrogen concentration of the gas stream that is intended to be passed through the gas consuming member. Is possible. In this case, as shown in FIG. 1, the gas analyzer 40 is preferably arranged to extract a sample of gas between the outlet 9 b of the second channel 9 of the heat exchanger 8 and the compressor 11. Is done. Thus, the gas sample to be analyzed is first preheated and secondly at atmospheric or virtual atmospheric pressure, which facilitates the analytical operation. However, the gas analyzer 40 may be located differently.

  According to another embodiment, the gas analyzer 40 is a machine for measuring the higher heating value of the combustible gas. The higher heating value is characteristic of the nitrogen concentration, and the heating value is a representative measurement of the nitrogen concentration of the gas stream. In such a case, the gas analyzer 40 can advantageously be integrated into one or more of the gas consuming members 2, 3, 4.

  The control unit 34 controls the pumping device so that the limit operating concentration for the gas consuming members 2, 3, 4 is exceeded, ie the limit nitrogen concentration above which the correct functioning of the gas consuming members 2, 3, 4 is no longer ensured. Arranged to ensure a lower nitrogen concentration in the gas stream intended to be passed through the gas consuming members 2, 3, 4 below.

According to a first predictive approach, the amount of liquid phase combustible gas flow delivered by the pump 26 is determined using a digital modeling tool. The digital modeling tool, on the one hand, ensures that the nitrogen concentration in the gas stream intended to be passed through the gas consuming members 2, 3, 4 is below the limit operating concentration for the gas consuming members 2, 3, 4 On the other hand, it is possible to determine the flow rate of the nominal liquid phase combustible gas stream delivered by the pump 26, which makes it possible to optimize the degree of reliquefaction during Joule-Thompson decompression To do.
The modeling tool specifically includes the following inflow parameters:

The individual nitrogen concentration in the liquid and / or gas phase of the combustible gas stored in the tank and / or in the gas stream intended to be passed through the gas consuming member 2, 3, 4;
The flow rate of the gas phase gas stream circulating in the gas phase gas collection circuit 6, and

  A function of the ratio between the first part of the compressed combustible gas stream conveyed to the gas consuming member 2, 3, 4 and the second part of the compressed combustible gas stream returned to the exchanger 8 As such, the flow rate of the extracted nominal liquid phase combustible gas flow is determined.

  As long as the nitrogen concentration in the gas stream intended to be passed through the gas consuming members 2, 3, 4 is below the critical threshold, the control unit 36 operates in the reliquefaction priority mode and the extracted liquid phase combustible The flow rate of the sex gas flow is determined such that the temperature T1 of the second part of the gas flow circulating in the intermediate circuit 15 is kept at the nominal temperature. Therefore, in this reliquefaction priority mode, the flow rate of the combustible gas flow is determined so as to optimize the degree of reliquefaction. When the combustible gas is a liquefied natural gas stored at atmospheric pressure, the nominal temperature for the second part of the gas stream circulating in the intermediate circuit 15 is typically −145 ° C. to −162 ° C., For example, about −160 ° C.

  In contrast, when the nitrogen concentration in the gas stream intended to be passed through the gas consuming member 2, 3, 4 is above or equal to the critical threshold, the control unit 36 is in nitrogen concentration priority mode. The flow rate of the operating and withdrawn liquid phase combustible gas stream is determined so that a representative measurement of the nitrogen concentration in the gas stream intended to be delivered to the gas consuming member is constrained to the target concentration Is done. The target nitrogen concentration is slightly below the critical concentration of the gas consuming member to be powered, for example about 2% to 3% below which the correct functioning of the gas consuming member 2, 3, 4 is no longer ensured. Selected.

  According to a second approach, the flow rate of the liquid phase combustible gas stream delivered by the pump 26 is such that, for example, a representative measurement of the nitrogen concentration in the gas stream circulating in the gas phase gas collection circuit 6 is a target concentration. Adjusted by PI or PID type adjustment to be suppressed. The target nitrogen concentration in the gas stream circulating in the gas phase gas collection circuit is determined as a function of the limit concentration of the gas consuming members 2, 3, 4 to be supplied.

  According to one embodiment, it is possible to combine the first and second above mentioned approaches.

  Furthermore, the increase in consumption of the gas consuming members 2, 3, 4 tends to result in a temporary increase in the nitrogen concentration in the gas stream at the inlet 9 a of the first channel 9 of the heat exchanger 8. Specifically, during an increase in the flow velocity of the first part of the combustible gas stream conveyed to the gas consuming member 2, 3, 4 compared to that of the second part of the flow returning to the exchanger 8, a transient phenomenon occurs. Is observed, which facilitates the gas flow circulating in the intermediate circuit 32 at the inlet 9a of the first channel 9 of the exchanger 8 due to the gas flow originating from the gaseous headspace of the tank, This leads to a transient increase in the nitrogen concentration of the gas stream at the inlet 9a of the first channel 9 of the exchanger 8. Therefore, according to one embodiment, in order to compensate for this phenomenon, the control unit 33 allows the flow rate drift of the first part of the gas flow conveyed to the gas consuming members 2, 3, 4 to be positive, Has a correction factor to increase the nominal flow rate.

  According to the first embodiment, the pump 26 operates at a constant power giving a constant flow rate, and the control unit 36 is one of the two valves 38, 39 as a function of the nominal flow rate determined by the control unit 33. A signal for controlling one and / or the other is generated. Therefore, the delivery speed of the pump 26 is constant, and one and / or the other of the two valves 38, 39 is a part conveyed to the spray member 21 of the liquid phase combustible gas flow and a part returning to the tank 5c. The distribution between and is adjusted to vary.

  According to the second embodiment, valve 38 is closed while valve 39 is opened, and control unit 36 generates a signal to control pump 26 to vary its delivery rate.

  According to an embodiment variant not shown, the installation 1 comprises an additional phase separator at the outlet of the chamber 20. Such a phase separator firstly directs the non-evaporated liquid phase in the chamber 20 to a return circuit 31 connected to the tanks 5a, 5b, 5c, 5d, and secondly, the gas phase is a heat exchanger. It is intended to be directed to the inlet 9 a of the eight first channels 9.

  In connection with FIG. 2, an installation 1 according to a second preferred embodiment is shown. This differs from the previously described facility described only in the characteristics of the cooling device 16.

  In FIG. 2, the cooling device 16 ensures heat transfer without material exchange between the compressed gas stream circulating in the intermediate circuit 15 and the liquid gas stream collected in the tank. An additional heat exchanger 17 is provided.

  To do this, the additional heat exchanger 17 comprises first and second channels 18, 19 comprising inlets 18a, 19a and outlets 18b, 19b, respectively. In order to optimize heat exchange, the additional heat exchanger 17 is advantageously a countercurrent exchanger. The first channel 18 is integrated into an intermediate circuit 15 that connects the heat exchanger 8 and the expansion device 14. In other words, the inlet 18 a of the first channel 18 is connected to the outlet 10 b of the second channel 10 of the heat exchanger 8, while the outlet 18 b of the first channel 18 is connected to the expansion device 14. The inlet 19 a of the second channel 19 is connected to the extraction circuit 35, while its outlet 19 b is connected to the gas phase gas extraction circuit 6.

In other words, the embodiment of FIG. 2 is particularly advantageous in that:
Firstly, heat is withdrawn from the second part of the compressed gas stream circulating in the intermediate circuit 15, which is particularly advantageous with regard to reliquefaction performance;

  Secondly, the vaporized gas stream is injected into the gas stream circulating in the gas phase gas collection circuit 6, which is the gas intended to be passed through the gas consuming members 2, 3, 4; It is particularly advantageous with respect to reducing the nitrogen concentration in the stream.

  The pumping device represented in FIG. 2 is simplified compared to that described in connection with FIG. 1 because it comprises only one pump 26. Furthermore, the installation 1 comprises a gas analyzer 40 for delivering a representative measurement of the nitrogen concentration in the gas stream intended to be passed through the gas consuming members 2, 3, 4 and an additional heat exchanger. A sensor 28 for measuring the temperature T1 of the second part of the gas flow at the outlet 18b of the seventeen first channels 18, ie at the inlet of the expansion device 14. As in the embodiment of FIG. 1, the control unit 36 is in a gas stream intended to be passed through the gas consuming members 2, 3, 4 below the limit operating concentration of the gas consuming members 2, 3, 4. A signal is generated to control the pump 26 to ensure the nitrogen concentration.

  Under certain operating conditions, particularly when the nitrogen concentration of the gas stream intended to be passed through the gas consuming members 2, 3, 4 is high, it is withdrawn from the tanks 5a, 5b, 5c, 5d and gas phase gas collection. It can be seen that the liquid-phase gas stream intended to be injected as a gas phase into the circuit 6 is too high to be completely evaporated in the additional heat exchanger 17. In other words, the gas flow at the outlet 19b of the second channel 19 of the additional heat exchanger 17 tends to be in a liquid-gas two-phase state.

  Therefore, in the embodiment variant illustrated in FIG. 4, an additional exchanger is used to address the difficulties associated with the possible presence of gas flow in the liquid-gas two-phase state at the outlet of the additional exchanger 17. 17 is arranged above the heat exchanger 8, so that the gas flow at the outlet 19b of the second channel 19 of the additional heat exchanger 17 is caused by gravity to the inlet of the first channel 9 of the heat exchanger 8. It is possible to flow to 9a.

  In another embodiment illustrated in FIG. 5, the cooling device 16 is described in conjunction with FIG. 2 to avoid the presence of gas flow in a liquid-gas two-phase condition at the outlet of the additional exchanger 17. In addition to the additional exchanger 17, a second is provided for transferring heat between the gas stream circulating in the gas phase gas collection circuit 6 and the liquid phase gas stream withdrawn from the tanks 5 a, 5 b, 5 c, 5 d. An additional heat exchanger 41 is provided.

  To do this, the second additional heat exchanger 41 has a first channel 42 integrated into the gas phase gas collection circuit 6, an inlet 43 a connected to the extraction circuit 35 and the gas phase gas collection circuit 6. And a second channel 43 having an outlet 43b connected to the second channel 43.

The two additional exchangers 17 and 41 are connected to the extraction circuit 35 via individual valves 44 and 45, respectively. Thus, the distribution of the gas stream withdrawn as a liquid phase from the tanks 5a, 5b, 5c, 5d between the two additional exchangers 17, 41 can be adjusted. In particular, the valves 44, 45 evaporate in the additional heat exchanger 17 when an excessive amount of gas, i.e. all of the liquid-phase gas stream withdrawn from the tanks 5a, 5b, 5c, 5d is directed to it. Only an amount of gas that cannot be done can be steered to be directed to the second additional heat exchanger 41.
FIG. 5 shows the following natural gas flow:
The gas phase gas stream withdrawn from the tank (curve a),
A first part (curve b) of a compressed combustible gas stream intended to be transported to a gas consuming member 2, 3, 4 in a prior art installation; and

  The installation according to FIG. 2, in which the flow rate of the gas withdrawn as a liquid phase from the tanks 5a, 5b, 5c, 5d and evaporated in the additional heat exchanger 17 is adjusted to optimize the reliquefaction yield As a function of the nitrogen concentration in the natural gas in the liquid state with respect to the first part of the compressed combustible gas stream (curve c) intended to be transported to the gas consuming members 2, 3, 4 in Represents the concentration.

  FIG. 5 shows the operation in which the gas phase gas stream withdrawn from the tank has a temperature of −120 ° C. and 70% of the flow rate of the combustible gas stream is returned to the heat exchanger 8 for reliquefaction therein. Represents a condition. In connection with FIG. 5, the spraying of liquid at the inlet 9 a of the first channel 9 of the heat exchanger 8 makes the gas consuming member 2, It is observed that it is possible to substantially reduce the nitrogen concentration of the gas stream intended to be delivered to 3,4. This is also achieved without degrading the reliquefaction yield.

  FIG. 6 represents a similar graph when only 50% of the flow rate of the combustible gas stream is returned to the heat exchanger 8 for reliquefaction therein.

  FIG. 7 shows the flow rate of the re-liquefied gas and the liquid phase gas withdrawn from the tank as a function of the flow rate of the second portion of the combustible gas stream returning to the heat exchanger 8 to be re-liquefied therein. It is a graph showing the difference between the flow rates of. The reliquefaction performance quality using the equipment as shown in FIG. 1 is represented on a curve a, and that using the equipment as shown in FIG. 2 is represented on a curve b. The operating conditions of this equipment are as follows, the nitrogen concentration of the gas phase natural gas collected from the tanks 5a, 5b, 5c and 5d is 20%, the temperature is -140 ° C, The total flow rate of the natural gas flow at the inlet 9 a of the first channel 9 of the exchanger 8 is 4,700 kg / hour, and the flow rate of the liquid natural gas flow removed from the tank circulates in the intermediate circuit 22. The temperature T1 of the second part of the gas stream is adjusted so as to be kept at a nominal temperature of −160 ° C. FIG. 7 thus demonstrates the increased effectiveness of the facility of FIG.

  FIG. 8 is intended to be transported to the gas consuming members 2, 3, 4 as a function of the flow rate of the second part of the combustible gas stream returning to the heat exchanger 8 to be reliquefied therein. Represents the nitrogen concentration in the first part of the gas stream. Curve a corresponds to the nitrogen content using the prior art equipment, i.e. when it is withdrawn in liquid phase from the tank and then no flow of evaporated gas is added to the gas phase gas collection circuit 6. , Curve b shows that gas is withdrawn in the liquid phase from the tanks 5a, 5b, 5c, 5d using a facility as illustrated in FIGS. Corresponds to the nitrogen content when injected. The operating conditions of this facility are the same as those described in connection with FIG. Thus, an installation such as that illustrated in FIGS. 1 and 2 can be used to adjust the gas flow conveyed to the gas consuming members 2, 3, 4 so as to match the operating conditions of the gas consuming members 2, 3, 4. It is observed that it is possible to significantly reduce the nitrogen concentration in the first part.

  FIG. 9 represents the difference between the flow rate of the reliquefied gas and the flow rate of the liquid phase gas withdrawn from the tank as a function of the flow rate of the second part of the combustible gas stream returning to the heat exchanger 8. It is a graph. The operating conditions of this facility are the same as those described in connection with FIG. Curve a shows the reliquefaction performance quality using the equipment according to the prior art, i.e. any flow of gas that has been withdrawn in the liquid phase from the tanks 5a, 5b, 5c, 5d While corresponding to when not added, curve b shows that gas is withdrawn in liquid phase from the tank using equipment as illustrated in FIG. 2, evaporated and injected into the gas phase gas collection circuit. Corresponding to the quality of reliquefaction performance.

  Thus, the use of a cooling device as described in connection with FIG. 2 reduces the nitrogen concentration of the gas stream intended to be passed through the gas consuming member 2, 3, 4 while at the same time combustible gas. Allows the reliquefaction yield to be increased to the flow rate value of the second part of the combustible gas stream without significantly reducing the reliquefaction yield beyond a certain flow rate value of the second part of the stream It is observed.

  In addition, the higher the temperature of the natural gas in the gas phase extracted from the tanks 5a, 5b, 5c, 5d, the higher the reliquefaction yield comparison is as compared to the equipment according to the prior art, as illustrated in FIG. Note that it is more advantageous.

  FIG. 10 shows a transfer system 40 for loading / withdrawing a combustible gas, such as liquefied natural gas, to form an interface between a vessel 41 and a floating or shore facility (not shown). As described above, the ship 41 includes equipment for feeding the combustible gas to the gas consuming member and liquefying the combustible gas. As an example, a liquid-tight and heat-insulating tank (not shown) has a substantially prismatic shape and is mounted in a double hull of a ship.

  Product transfer is ensured by an immersion cryogenic line denoted 42. A transfer system 40 that forms an interface between the vessel 41 and floating or onshore equipment connects at least one platform 43 that supports a storage / handling gantry 44 and a submerged cryogenic line 42 to a flexible transfer pipe 46. And a main platform 45 for capturing all the devices that enable this. Each flexible transfer pipe 46 is intended to be connected to a vessel manifold 47 through a connection module 48. The ship's manifold 47 is connected to the tank using a loading / unloading pipeline arranged on the upper deck of the ship 41 to transport liquefied gas cargo from or to the tank.

  The main function of the gantry 44 is to allow handling and storage of the transfer parts, ie, the movable ends of each connection module 48 and flexible transfer pipe 46, using a crane and winch.

  According to an embodiment, the transfer system comprises three parallel flexible transfer pipes 46, two of which allow liquefied natural gas to be transferred between floating or onshore equipment and the ship. The third transfer pipe, on the other hand, allows gas to be transferred to balance the pressure in the gaseous headspace of the ship's tank.

  To generate the pressure required for the transfer of liquefied gas, an on-board pump in the ship 41 is used and / or the pump is installed in land equipment and / or A pump is adapted to the transfer system 40.

  Although the present invention has been described in connection with some specific embodiments, this is in no way limited to it, and all these technical means of the means described are within the scope of the present invention. It is obvious to have equivalents and combinations thereof.

  Use of the verb “comprises” or “contains” or “contains” and its conjugations does not exclude the presence of elements or steps other than those listed in a claim.

Accordingly, methods and equipment implemented in accordance with some non-limiting embodiments of the present technology can be represented as follows, presented in numbered appendices.
(Appendix 1) A facility (1) for feeding a combustible gas to a gas consuming member (2, 3, 4) and liquefying the combustible gas, the facility comprising:
A leak-proof and insulated tank (5a, 5b, 5c, 5d) with an inner space intended to be filled with a combustible gas in a liquid-gas two-phase equilibrium;
-Inlets that appear in the inner space of the tanks (5a, 5b, 5c, 5d) and are arranged to draw the gas phase combustible gas flow from the inner space of the tanks (5a, 5b, 5c, 5d) ( A gas phase gas collecting circuit (6) comprising 7a, 7b, 7c, 7d);
A first and second channel (9, 10) and a heat exchange wall for transferring heat from the second channel (10) to the first channel (9); ) And the second channel (10) are heat exchangers (8) each comprising an inlet (9a, 10a) and an outlet (9b, 10b), the inlet of the first channel (9) (9a) a heat exchanger (8) connected to the gas phase gas collection circuit (6) so as to heat the gas phase combustible gas stream in the heat exchanger (8);
Upstream of the outlet (9b) of the first channel (9) of the heat exchanger (8) so as to compress the combustible gas stream at the outlet of the first channel (9) of the heat exchanger (8). A second part of the combustible gas stream connected to carry the first part of the combustible gas stream to the gas consuming member (2, 3, 4) and to cool the second part of the combustible gas stream A compressor (11) connected downstream to a three-way connector (12, 13) capable of transporting to the inlet (10a) of the second channel (10) of the heat exchanger (8);
A return circuit (31) connected upstream via the intermediate circuit (15) to the outlet (10b) of the second channel (10) of the heat exchanger (8) and leading to the tank (5a, 5b, 5c, 5d) Expansion device (14) connected downstream) to the expansion device (14) arranged to depressurize the second part of the combustible gas stream originating from the intermediate circuit (15);
With
This also comprises a cooling device (16) comprising an extraction circuit (35), which emerges in the inner space of the tank (5a, 5b, 5c, 5d) and the tank (5a, 5b, 5c, 5d). A suction port (27) arranged to draw a liquid phase flammable gas stream from the interior space of the), the cooling device (16) evaporates the liquid phase flammable gas stream drawn from the tank, Liquid phase combustible gas stream withdrawn from the tank and gas phase gas collection to cool the combustible gas stream to be cooled, using the latent heat of evaporation of the liquid phase combustible gas stream withdrawn from the tank Between the gas phase combustible gas stream circulating in the circuit (6) and the second part of the combustible gas stream circulating in the intermediate circuit (15), to be cooled. Characterized in that it is arranged to transfer heat , Equipment (1).
(Supplementary note 2) The combustible gas is a gaseous mixture containing nitrogen, and the cooling device (16) transports the vaporized gas flow in the cooling device (16) to the gas phase gas collection circuit (6), The facility (1) according to appendix 1, arranged to reduce the nitrogen content of the combustible gas stream circulating in the phase gas collection circuit (6).
(Supplementary note 3) The cooling device (16) is connected to the first and second channels (18, 19) and from the first channel (18) of the additional heat exchanger (17) to the second channel (19). An additional heat exchanger (17) with a heat exchange wall for transferring heat, wherein the first channel (18) and the second channel (19) are respectively inlet (18a, 19a) ) And outlets (18b, 19b), the first channel (18) being integrated into an intermediate circuit (15) connecting the heat exchanger (8) and the expansion device (14), the second channel The inlet (19a) of the channel (19) of the second channel (19) is connected to the extraction circuit (35) of the cooling device (16), and the outlet (19b) of the second channel (19) is connected to the gas phase gas collection circuit (6) The facility according to appendix 2, connected to
(Supplementary Note 4) The additional heat exchanger (17) is stacked above the heat exchanger (8), and the outlet of the second channel (19) of the additional heat exchanger (17) is connected to the heat exchanger ( 8) connected to the inlet (9a) of the first channel (9), so that the liquid-phase gas stream is heated by gravity from the outlet of the second channel (19) of the additional heat exchanger (17). The facility according to appendix 3, capable of flowing to the inlet (9a) of the first channel (9) of the exchanger (8).
(Supplementary Note 5) The cooling device (16) includes a first channel (42) integrated into the gas phase gas collection circuit (6), an inlet (43a) connected to the extraction circuit (35), and a gas phase gas collection. The facility according to appendix 3, comprising a second additional heat exchanger (41) comprising a second channel (43) comprising an outlet (43b) connected to the circuit (6).
(Supplementary Note 6) The cooling device (16) includes the inlet (7a, 7b, 7c, 7d) of the gas phase gas collecting circuit (6) and the inlet (9a) of the first channel (9) of the heat exchanger (8). Gas phase gas flow withdrawn from the inner space of the tank, connected to the chamber (20) integrated with the gas phase gas collection circuit (6) between and the extraction circuit (35) of the cooling device (16) The liquid phase combustible gas is arranged to be sprayed into the chamber (20) so as to cool and reduce the nitrogen content of the combustible gas stream circulating in the gas phase gas collection circuit (6). The facility according to appendix 2, comprising a spray member (21).
(Supplementary note 7) The cooling device (16) draws a liquid phase combustible gas stream through the inlet (27) of the cooling device (16) and delivers it into the extraction circuit (35). The facility according to any one of supplementary notes 2-6, comprising a device (26).
(Supplementary note 8) A representative measurement of the nitrogen concentration in the first portion of the combustible gas stream may be delivered, and the control unit (36) is the first of the combustible gas stream below the critical operating concentration of the gas consuming member. Pumping device (26) as a function of a representative measurement of the nitrogen concentration in the first part of the combustible gas stream delivered to the gas consuming member (2, 3, 4) to ensure the nitrogen concentration in the part of The facility of claim 7, comprising a gas analyzer (40) arranged to generate a control signal for.
(Supplementary note 9) The control unit (36) provides a representative measurement of nitrogen concentration and gas in the first part of the combustible gas stream so as to keep the nitrogen concentration in the first part of the combustible gas stream to a nominal concentration. The facility of claim 8, arranged to generate a control signal for the pumping device (26) as a function of a nominal concentration below a limit operating concentration of the consumable member.
(Supplementary Note 10) The control unit (36)
-This is below the representative measurement of the nitrogen concentration in the first part of the combustible gas stream and the critical operating concentration of the gas consuming member so that the nitrogen concentration in the first part of the combustible gas stream is kept to the nominal concentration A nitrogen concentration priority mode that generates a control signal for the pumping device (26) as a function of the nominal concentration;
The pumping device as a function of the temperature measurement T1 and the nominal temperature of the second part of the gas stream circulating in the intermediate circuit (15) at the inlet of the expansion device (14) so that the temperature T1 is kept at the nominal temperature Reliquefaction priority mode for generating a control signal for (26);
Have
The control unit (36) is arranged to switch from a nitrogen concentration priority mode to a reliquefaction priority mode as a function of a representative measurement of nitrogen concentration in the first part of the combustible gas stream. Equipment.
(Supplementary note 11) The facility according to any one of Supplementary notes 1 to 10, wherein the expansion device (23) is an expansion valve.
(Supplementary note 12) Connected upstream to the expansion device (14), on the one hand downstream to the return circuit (31) connected to the tank and on the other hand to the return pipe (32) connected to the gas phase gas collection circuit (6) A phase separator (25) connected at the end, the phase separator (25) transports the liquid phase of the combustible gas stream to the return circuit (31) and the gas phase of the combustible gas stream to the return pipe ( 32. The facility according to any one of appendices 1-11, arranged to be transported to 32).
(Supplementary note 13) A process for feeding a combustible gas to a gas consuming member using the facility according to any one of supplementary notes 1-12 and liquefying the combustible gas,
A gas-phase combustible gas stream is conveyed from the inlet (7a, 7b, 7c, 7d) of the gas-phase gas collecting circuit (6) to the inlet (9a) of the first channel (9) of the heat exchanger (8) And steps to
Transferring heat from the second channel (10) of the heat exchanger (8) to the first channel (9);
-Compressing the combustible gas stream exiting the first channel (9) of the heat exchanger (8);
Conveying the first part of the compressed combustible gas stream to the gas consuming member (2, 3, 4) and the second part of the compressed gas stream to the second channel of the heat exchanger (8); Carrying to the inlet (10a) of (10);
Conveying the second part of the combustible gas stream from the second channel of the heat exchanger (8) via the intermediate circuit (15) to the expansion device (14);
-Depressurizing the second part of the combustible gas stream originating from the intermediate circuit (15);
Transporting at least part of the liquid phase part of the second part of the decompressed combustible gas stream to the tank (5a, 5b, 5c, 5d);
-Extracting the liquid phase combustible gas stream from the inner space of the tank (5a, 5b, 5c, 5d);
-Evaporate the liquid flammable gas stream withdrawn from the tank and use the latent heat of evaporation of the liquid phase flammable gas stream withdrawn from the tank to remove from the tank to cool the gas stream to be cooled. Selected liquid phase combustible gas stream, a gas phase gas stream circulating in the gas phase gas collecting circuit (6) and a second part of the gas stream circulating in the intermediate circuit (15) Transferring heat to and from the gas stream to be
Including the process.
(Supplementary note 14) The process according to supplementary note 13, wherein the combustible gas is a gaseous mixture containing nitrogen and the vaporized gas stream in the cooling device (16) is conveyed to the gas phase gas collection circuit (6). .
(Supplementary note 15) A variable representing the nitrogen concentration in the first part of the combustible gas stream is measured, and the flow rate of the liquid phase combustible gas stream circulating in the extraction circuit (35) of the cooling device (16) is 15. Process according to claim 14, adjusted as a function of a variable representing the nitrogen concentration in the first part of the sex gas stream.
(Supplementary note 16) The flow rate of the liquid phase combustible gas stream circulating in the extraction circuit (35) of the cooling device (16) is combustible so that the nitrogen concentration in the first part of the combustible gas stream is kept at the nominal concentration. The process of claim 15 adjusted as a function of a variable representing the nitrogen concentration in the first part of the sex gas stream and a nominal concentration.
(Additional remark 17) A ship (40) provided with the installation (1) of any one of Additional remarks 1-12.
(Supplementary note 18) Ship (40) according to supplementary note 17, wherein the flammable gas is passed from the floating or terrestrial storage facility to or from the tank of the ship through or from the cryogenic transfer pipe (42, 46). A process for loading or unloading.
(Supplementary note 19) A system for transferring flammable gas, wherein the ship (40) according to supplementary note 17 and a tank installed in the ship's hull are connected to a floating or shore storage facility. System comprising a cryogenic transfer pipe (42, 46) and a pump for driving a combustible gas flow from or to a floating or on-shore storage facility or to a tank of a ship through an insulated pipeline .

Claims (19)

A facility for feeding a combustible gas to a gas consuming member and liquefying the combustible gas, the facility comprising:
A leak-proof and insulated tank comprising an inner space intended to be filled with a combustible gas in a liquid-gas two-phase equilibrium;
A gas phase gas collection circuit comprising a suction port that appears in the inner space of the tank and is arranged to draw a gas phase combustible gas stream from the inner space of the tank;
-A first and second channel and a heat exchange wall for transferring heat from the second channel to the first channel, the first channel and the second channel, respectively, A heat exchanger comprising an inlet and an outlet, wherein the inlet of the first channel is connected to the gas phase gas collection circuit to heat the gas phase combustible gas stream in the heat exchanger With a heat exchanger,
-Connected upstream to the outlet of the first channel of the heat exchanger so as to compress the flammable gas stream at the outlet of the first channel of the heat exchanger; A portion is transported to the gas consuming member and a second portion of the combustible gas stream is transported to an inlet of a second channel of the heat exchanger for cooling the second portion of the combustible gas stream. Capable of being connected downstream to a three-way connector, with a compressor;
An expansion device connected upstream to the outlet of the second channel of the heat exchanger via an intermediate circuit and connected downstream to a return circuit leading to the tank, the combustible coming from the intermediate circuit An expansion device arranged to depressurize a second portion of the sex gas stream;
With
It also comprises a cooling device comprising an extraction circuit, the extraction circuit having an inlet arranged in the inner space of the tank and arranged to extract a liquid phase combustible gas flow from the inner space of the tank The cooling device evaporates the liquid phase combustible gas stream withdrawn from the tank, and uses the latent heat of evaporation of the liquid phase combustible gas stream withdrawn from the tank to combust the gas to be cooled. A liquid phase combustible gas stream removed from the tank, a gas phase combustible gas stream circulating in the gas phase gas collecting circuit, and a combustible gas stream circulating in the intermediate circuit so as to cool the stream Equipment characterized in that it is arranged to transfer heat to and from the combustible gas stream to be cooled, selected from the second part.   The combustible gas is a gaseous mixture containing nitrogen, and the cooling device conveys the vaporized gas stream in the cooling device to the gas phase gas collection circuit and circulates in the gas phase gas collection circuit The facility of claim 1, arranged to reduce the nitrogen content of the combustible gas stream.   The cooling device comprises first and second channels and a heat exchange wall for transferring heat from the first channel to the second channel of the additional heat exchanger. The first channel and the second channel each comprise an inlet and an outlet, the first channel being integrated into the intermediate circuit connecting the heat exchanger and the expansion device The facility of claim 2, wherein an inlet of the second channel is connected to an extraction circuit of the cooling device and an outlet of the second channel is connected to the gas phase gas collection circuit.   The additional heat exchanger is stacked above the heat exchanger, the outlet of the second channel of the additional heat exchanger is connected to the inlet of the first channel of the heat exchanger, and the liquid phase The installation of claim 3, wherein a gas stream can flow by gravity from an outlet of the second channel of the additional heat exchanger to an inlet of the first channel of the heat exchanger.   The cooling device comprises a first channel integrated into the gas phase gas collection circuit and a second channel comprising an inlet connected to the extraction circuit and an outlet connected to the gas phase gas collection circuit. The installation of claim 3, comprising a second additional heat exchanger. The cooling device includes a chamber integrated into the gas phase gas collection circuit between an inlet of the gas phase gas collection circuit and an inlet of the first channel of the heat exchanger, and an extraction circuit of the cooling device. A liquid phase combustible gas is connected to cool the gas phase gas stream removed from the inner space of the tank and reduce the nitrogen content of the combustible gas stream circulating in the gas phase gas collection circuit. The apparatus of claim 2, comprising a spray member arranged to spray into the chamber.   7. The cooling device of claim 2-6, wherein the cooling device comprises a pumping device capable of sucking the liquid phase combustible gas stream through the inlet of the cooling device and delivering it into the extraction circuit. The equipment according to any one of the above.   A representative measurement of nitrogen concentration in the first portion of the combustible gas stream may be delivered, and the control unit is nitrogen in the first portion of the combustible gas stream that is below a critical operating concentration of the gas consuming member. Arranged to generate a control signal for the pumping device as a function of a representative measurement of nitrogen concentration in the first portion of the combustible gas stream delivered to the gas consuming member to ensure concentration. The equipment according to claim 7, comprising a gas analyzer.   The control unit includes a representative measurement of the nitrogen concentration in the first portion of the combustible gas stream and the gas consuming member so as to keep the nitrogen concentration in the first portion of the combustible gas stream to a nominal concentration. 9. The facility of claim 8, arranged to generate a control signal for the pumping device as a function of the nominal concentration below a critical operating concentration. The control unit is
-A representative measurement of the nitrogen concentration in the first part of the combustible gas stream and the limiting action of the gas consuming member so that this limits the nitrogen concentration in the first part of the combustible gas stream to a nominal concentration; A nitrogen concentration priority mode that generates a control signal for the pumping device as a function of the nominal concentration below a concentration;
-For the pumping device as a function of the temperature measurement T1 of the second part of the gas stream circulating in the intermediate circuit at the inlet of the expansion device and the nominal temperature so that the temperature T1 is kept at the nominal temperature Reliquefaction priority mode to generate control signals;
Have
9. The control unit according to claim 8, wherein the control unit is arranged to switch from the nitrogen concentration priority mode to the reliquefaction priority mode as a function of a representative measurement of nitrogen concentration in the first portion of the combustible gas stream. The equipment described.   The facility according to claim 1, wherein the expansion device is an expansion valve.   A phase separator connected upstream to the expansion device, connected on the one hand to a return circuit leading to the tank and on the other hand to a return pipe connected to the gas phase gas collecting circuit; The separator according to any of claims 1-6, wherein the separator is arranged to carry the liquid phase of the combustible gas stream to the return circuit and to transport the gas phase of the combustible gas stream to the return pipe. The equipment according to claim 1. A process for feeding a combustible gas to a gas consuming member using the facility according to claim 1 and liquefying the combustible gas,
Conveying a gas phase combustible gas stream from an inlet of the gas phase gas collection circuit to an inlet of the first channel of the heat exchanger;
-Transferring heat from the second channel of the heat exchanger to the first channel;
-Compressing the combustible gas stream exiting the first channel (9) of the heat exchanger;
Conveying a first part of the compressed combustible gas stream to the gas consuming member and conveying a second part of the compressed gas stream to the inlet of the second channel of the heat exchanger; When,
Conveying a second part of the combustible gas stream from a second channel of the heat exchanger via the intermediate circuit to the expansion device;
-Depressurizing a second portion of the combustible gas stream originating from the intermediate circuit;
Transporting at least a portion of the liquid phase portion of the second portion of the reduced combustible gas stream to the tank;
-Withdrawing a liquid phase combustible gas stream from the inner space of the tank;
The liquid phase combustible gas stream withdrawn from the tank is evaporated and the latent heat of evaporation of the liquid phase combustible gas stream withdrawn from the tank is used to cool the gas stream to be cooled; A liquid phase combustible gas stream withdrawn from the tank, a gas phase gas stream circulating in the gas phase gas collection circuit and a second portion of the gas stream circulating in the intermediate circuit is cooled. Transferring heat to and from the gas stream to be
Including the process.   The process of claim 13, wherein the combustible gas is a gaseous mixture comprising nitrogen and the vaporized gas stream in the cooling device is conveyed to the gas phase gas collection circuit.   A variable representing the nitrogen concentration in the first portion of the combustible gas stream is measured, and the flow rate of the liquid phase combustible gas stream circulating in the extraction circuit of the cooling device is the first flow rate of the combustible gas stream. 15. The process of claim 14, wherein the process is adjusted as a function of a variable representing the nitrogen concentration in the portion.   The flow rate of the liquid phase combustible gas stream circulating in the extraction circuit of the cooling device is such that the first concentration of the combustible gas stream is such that the nitrogen concentration in the first part of the combustible gas stream is kept at a nominal concentration. The process of claim 15, wherein the process is adjusted as a function of a variable representing the nitrogen concentration in said portion and said nominal concentration.   A ship comprising the facility according to claim 1.   18. A process for loading or discharging in a vessel according to claim 17, wherein the combustible gas is passed through a cryogenic transfer pipe, from a floating or terrestrial storage facility, to or from the vessel tank.   18. A cryogenic transfer system for transferring flammable gas, wherein the ship according to claim 17 and a tank installed in the ship's hull are arranged to connect to a floating or shore storage facility. A system comprising a pipe and a pump for driving a combustible gas flow to or from the floating or on-shore storage facility, or to the tank of the ship, through the insulated pipeline.

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