KR102195833B1 - Improved system for treating and supplying natural gas comprising a circuit for heating the tank - Google Patents

Abstract

The present invention relates to a system for treating and delivering natural gas, the system comprising:
-A supply circuit that feeds energy-producing equipment selected from combustion engines, fuel cells or gas turbines, where natural gas is delivered from the liquefied natural gas storage tank (2) to the energy-producing equipment (4, 6). A supply circuit, comprising: an upstream portion connected to the tank 2 and a downstream portion connected to the energy-production equipment 4,6;
-A burner (5) supply circuit, which enables the delivery of natural gas from the tank (2) to the burner (6) and includes an upstream portion connected to the tank (2) and a downstream portion connected to the burner (5); And
-A heating circuit for heating the tank (2), capable of collecting a gas flow from the bottom of the tank (2) and injecting the gas flow into the upper portion of the tank (2), the tank (2) And a heating circuit comprising an upstream part connected to the pipeline 52 opened into the lower part of the tank 2 and a downstream part connected to the pipeline 71 opened into the upper part of the tank 2.

Description

An improved system for treating and supplying natural gas comprising a circuit for heating the tank.

The present invention relates to the technical field of ships comprising a liquefied natural gas storage tank. The present invention relates in particular to an on-board system for processing and delivering natural gas, wherein the built-in system can be supplied with natural gas to energy-producing equipment such as combustion engines, fuel cells or gas turbines. So that the tank can be heated, in particular so that the tank can be inspected.

Liquefied natural gas storage tank, processing the gas and transferring the gas from the tank to one or more burners of energy-production equipment and/or energy production equipment of one or more items, such as combustion engines, fuel cells or gas turbines. Ships comprising a system for delivering are known from the prior art.

Such ships are particularly subject to thorough inspection and maintenance work. Specifically, liquefied natural gas storage tanks must be inspected regularly.

To do this, the tanks are heated to reach a temperature suitable to enable such inspection after being emptied.

One idea that underlies the invention is, on the one hand, allowing the energy-producing equipment to be selected from combustion engines, fuel cells and gas turbines, on the other hand, allowing the burner to be supplied, and also for effective heating of the tank. The idea is to propose an improved system for processing and delivering natural gas, which makes it possible.

According to one embodiment, the present invention provides a system for processing and delivering natural gas, the system comprising:

-A supply circuit that feeds energy-producing equipment selected from combustion engines, fuel cells or gas turbines, allowing natural gas to be delivered from a liquefied natural gas storage tank to the energy-producing equipment and connected to the tank A supply circuit comprising an upstream portion and a downstream portion connected to the energy-production equipment;

-A burner supply circuit enabling the delivery of natural gas from the tank to the burner and comprising an upstream portion connected to the tank and a downstream portion connected to the burner; And

-A heating circuit for heating a tank, capable of collecting a gas flow from the lower part of the tank and injecting the gas flow into the upper part of the tank, the upstream part connected to the pipeline open into the lower part of the tank and Including; a heating circuit comprising a downstream portion connected to the pipeline opened into the upper portion of the tank,

-The energy-production equipment supply circuit and the heating circuit comprise a part of a circuit in common including a compressor, the compressor having an inlet and an outlet, and the pressure and temperature of the gas flow are to be increased. And the circuit portion is jointly bounded by a first three-way connection member switchable upstream and a second three-way connection member switchable downstream, the switchable first three-way connection member The upstream part of the engine supply circuit or the upstream part of the heating circuit can be selectively connected to the inlet of the compressor, and the switchable second three-way connecting member provides the outlet of the compressor to the energy-producing equipment Selectively connectable to said downstream portion of a circuit or said downstream portion of said heating circuit;

-The downstream portion of the heating circuit comprises a third three-way connecting member, the third three-way connecting member being connected to the burner in order to remove a portion of the gas flow delivered toward the burner in the heating circuit. It allows the downstream part of the heating circuit to be connected to the downstream part of the feeding circuit for feeding.

Such a system, on the one hand, allows the tank to be efficiently heated while recovering the natural gas removed from the liquefied natural gas storage tank, on the one hand, and on the other hand, the use of components such as the compressor allows the It is particularly advantageous in that it has an optimized design to be able to perform four functions.

According to some embodiments, such a natural gas treatment and delivery system may include one or more of the following features.

-The downstream part of the heating circuit includes a connection section for connection to the outlet of the compressor and a return section leading to the tank, and a circuit for feeding the heating circuit and the burner The downstream portion of the jointly includes a portion containing a gas heating appliance, the gas heating appliance having an inlet and an outlet, the portion being switchable upstream by a fourth three-way connecting member, and The connection portion at the outlet of the compressor of the heating circuit or the upstream portion of the burner supply circuit, which is jointly bounded by the third three-way connection member, and the switchable fourth three-way connection member May be selectively connected to the inlet of the heating device, and the third three-way connecting member includes the outlet of the gas heating device incidentally to the downstream part of the burner supply circuit, and a tank return part of the heating circuit. (return-to-tank section).

-Said natural gas treatment and delivery system comprises a switchable three-way connecting member, said switchable three-way connecting member being selectively opened into said upper part of said tank, on the one hand allowing said gas flow The downstream of the heating circuit to be injected into the top of the tank, or on the other hand, of the supply circuit to feed the energy-producing equipment so that the gas evaporated into the tank can be collected. It makes it possible to connect to the upstream part and/or the upstream part of the burner supply circuit.

-Comprising a tank filling circuit and a switchable three-way connecting member, said switchable three-way connecting member selectively allowing the pipeline open into the lower part of the tank, on the one hand to cause gas flow It is either connected to the upstream part of the heating circuit so that it can be collected in the lower part of the tank, or, on the other hand, to the tank filling circuit.

-The energy-production equipment supply circuit comprises a phase separator, the phase separator downstream, on the one hand, a heavy fraction of natural gas comprising hydrocarbons with the longest carbon chain ( heavy fraction) is connected to a return pipe that allows it to be returned to the tank in the form of condensate, on the other hand, to lead a light fraction of natural gas containing hydrocarbons with the shortest carbon skeleton. It is connected to a pipe connected to the inlet of the compressor.

-The supply circuit feeding the burner bypasses the phase separator.

-The compressor is typically a multistage compressor.

The system comprises a compressor protection device, the protection device comprising a recirculation loop equipped with a valve, the valve allowing the gas flow collected downstream of the compressor to be returned upstream of the compressor.

-A circuit part common to the supply circuit and the heating circuit for feeding the energy-production equipment comprises a plurality of compressors arranged in parallel.

According to one embodiment, the present invention relates to a ship, the ship comprising a liquefied gas storage tank, a combustion engine as energy-producing equipment, an energy-producing equipment selected from a fuel cell and a gas turbine, an energy production facility equipped with a burner ( energy production installation), and the natural gas treatment and delivery systems mentioned above.

In one embodiment the energy-producing equipment is intended for propulsion of the vessel.

According to one embodiment the present invention also relates to a method of filling a tank of a ship mentioned above, wherein the fluid is transferred from a floating storage facility or an onshore storage facility through insulated pipelines of the ship. Delivered to the tank.

According to one embodiment, the present invention also relates to a system including the vessel mentioned above, wherein the system is arranged in a manner that connects the tank installed in the hull of the vessel to a floating storage facility or an onshore storage facility. Adiabatic pipelines and a pump for driving a stream of fluid from the floating storage facility or the onshore storage facility through the insulated pipelines to the tank of the vessel.

The invention will be better understood by reading the following description of several specific embodiments of the invention given by way of non-limiting illustration only with reference to the accompanying drawings, and other objects, details, features and The advantages will become more evident.
1 is a schematic diagram of a natural gas treatment and delivery system in a ship.
In Fig. 2 the system of Fig. 1 is shown, in which the path of natural gas for supplying energy-producing equipment to propel the vessel and supplying energy-producing equipment to generate electricity is by emboldening. ) Highlighted.
In FIG. 3 the system of FIG. 1 is shown, in which the path of natural gas for supplying energy-producing equipment to generate electricity is highlighted in bold.
In Fig. 4 the system of Fig. 1 is shown, in which the path of natural gas to the burner of an energy production facility for recovering and utilizing a heavy fraction of natural gas is highlighted.
In Fig. 5 the system of Fig. 1 is shown, in which the path of the natural gas evaporated in the tank towards the burners of the energy production facility is highlighted.
In Fig. 6, the system of Fig. 1 is shown, in which the path of natural gas in the implementation of the tank heating method is highlighted.
7 shows a gas storage tank and a ship with energy-producing equipment supplied with natural gas for propulsion of the ship.

In this specification and in the claims, the terms "upstream" and "downstream" are defined with reference to the direction in which natural gas is circulated.

7 shows a ship 1 with one or more liquefied natural gas storage tanks 2 and with a propulsion unit supplied with natural gas, the propulsion unit comprising combustion engines, fuel cells or gas turbines. One or more energy-producing equipment items (4) selected from. Such a vessel 1 may in particular be a methane tanker intended for transporting liquefied natural gas, but may also be intended for any other application. By way of example, the ship may be a merchant ship, a passenger ship, a fishing ship or the like.

1 shows a natural gas storage tank 2 and a system 3 conveyed in a ship 1 for processing and delivering natural gas. The natural gas treatment and delivery system 3 is adapted to supply the energy-producing equipment 4 of the propulsion unit as shown in FIG. 2 and the burner 5 as shown in FIGS. 4, 5 and 6 And, optionally, to feed to other energy-producing equipment 6 such as a gas turbine, fuel cell, or combustion engine of a generator as shown in FIGS. 2 and 3.

The tank 2 is a sealed and insulated tank adapted for storage of liquefied natural gas (LNG). The tank 2 may in particular be of the type with membranes that allow the liquefied natural gas to be stored at atmospheric pressure.

The energy-producing equipment 4 of the propulsion unit is selected from combustion engines, fuel cells and gas turbines. When the energy-producing equipment 4 is a combustion engine, the engine may be a hybrid engine running on diesel/natural gas. Such engines 4 operate in a diesel mode in which only diesel is supplied to the engine, or a small amount of pilot diesel is injected to start combustion, and the fuel for the engine is mainly natural gas. Can operate in mode.

The output shaft (output shaft) coupled to the mechanical energy generated by the energy-producing equipment (4) is coupled to one or more screws for propulsion of a ship or an alternator that allows the mechanical energy to be converted into electrical energy It can be coupled to an alternator, in which case electrical energy is used to power an electric motor coupled to a screw for propulsion of the vessel. If a combustion engine is used in the latter alternative, the engine may in particular be an engine of the DFDE type, which DFDE stands for Dual Fuel Diesel Electric.

The energy-producing equipment 6 for generating electricity can be a hybrid combustion engine, fuel cell or gas turbine, for example of type DFDE, operating on diesel/natural gas.

The burner 5 is integrated into an energy production facility. The energy production plant in particular comprises a boiler for producing steam. The steam may be intended to feed steam turbines for the production of energy and/or to feed the heating network of the vessel 1.

In Fig. 2 are shown two circuits each feeding the energy-producing equipment 4 of the propulsion unit and the energy-producing equipment 6 for generating electricity. The circuit that feeds the energy-producing equipment 4 of the propulsion unit will be referred to hereinafter as the "main circuit", while the energy-producing equipment 6 for producing electricity is fed. This circuit will be referred to as a “secondary circuit”. It is noted that the main circuit may be used to deliver natural gas to the sub circuit. Such a configuration provides redundancy for the supply of the sub-circuit, which protects against potential malfunction.

The main circuit includes a suction pipeline 7a which is opened toward the lower portion of the tank 2 and fed by a pump 8a. The suction pipeline 7a conveys the liquefied natural gas in a three-way connection 23, which means that the suction pipeline 7a is also referred to as an evaporator on the one hand. The valve 223, connected to the pipeline 24 with a valve 123, connected to the inlet of the forced vaporization installation 9a, and on the other hand to an atomizer 10a. ) Makes it possible to be connected to the provided pipeline 25. The forced evaporation facility 9a allows the liquefied natural gas to be converted into a gas stream. The outlet of the forced evaporation facility 9a is connected to the atomizer 10a by a pipe 26 so that the gas stream is conveyed to the atomizer 10a. The atomizer 10a may spray liquefied natural gas collected upstream of the forced evaporation facility 9a into the gas stream obtained at the outlet of the forced evaporation facility 9a. Accordingly, the atomizer 10a allows the gas stream to be cooled such that the heaviest hydrocarbons, more precisely, hydrocarbons having the longest carbon skeleton and the highest evaporation temperature, are condensed. The gas stream is typically cooled to a temperature lower than -100°C.

When leaving the atomizer 10a, the gas stream filled with droplets of natural gas in a suspended state is conveyed through the pipeline 27 to the phase separator 11a. This phase separator 11a, often referred to as a mist separator, allows the liquid phase to be separated from the gaseous phase. The liquid phase consists of the heaviest hydrocarbons, specifically the heaviest fraction of natural gas containing hydrocarbons with the longest carbon skeleton. The heavy fraction of the natural gas is sent to the storage tank 2 via a condensate return pipeline 12a in the form of condensate. The condensate return pipeline 12a is provided with a condensate collection container 72a, and the condensate collection container is periodically purged when the level of the condensate therein reaches a threshold. The gaseous phase itself composed of a light fraction of the natural gas containing hydrocarbons having the shortest carbon skeleton is conveyed to the gas heating device 13 via the pipeline 28, the gas heating device 13 This allows the gas phase to be heated to a typical temperature of 30°C. Such gas heating devices 13 are typically gas/liquid or gas/gas heat exchangers. Here, the gas heating device 13 is provided with a recirculation loop 29.

Finally, the gas flow at the outlet of the gas heating device 13a can be conveyed via the pipeline 30 towards the energy-producing equipment 4 of the pushing unit.

Similarly, the sub-circuit comprises a suction pipeline 7b which opens toward the bottom of the tank 2 and is fed by a pump 8b. The suction pipeline 7b allows the liquefied natural gas to be conveyed to the forced evaporation plant 9b and to the two atomizers 10b and 31. To this end, the suction pipeline 7b is connected to a pipeline 33 provided with a valve 132 on the one hand and leading to the atomizer 31 via a three-way connection 32, on the other hand It is connected to a pipeline 34 equipped with a valve 232, and the pipeline 34 itself is connected to a three-way connection portion 35, and the three-way connection portion 35 is the pipeline 34 On the other hand, it is connected to the atomizer 10b via a pipeline 36 equipped with a valve 135, and on the other hand, the forced evaporation facility 9b via a pipeline 17 equipped with a valve 235. ) To the inlet.

The outlet of the forced evaporation facility (9b) is connected to the atomizers (10a, 31) by a series of pipelines (37, 38, 39), the atomizers to condense the heaviest hydrocarbons. Liquefied natural gas can be sprayed. The gas flow leaving the atomizer 31 is conveyed via a pipeline 40 to the inlet of the separator 11b.

Similarly, the phase separator 11b allows the liquid phase to be separated from the gas phase and allows the condensate to be returned to the tank 2 via the condensate return pipeline 12b. The condensate return pipeline 12b is provided with a container 72b for collecting the condensate, which is periodically purged when the level of the condensate therein reaches a threshold.

On the other hand, at the outlet from the phase separator 11b, the gas phase consisting of a light fraction of the natural gas is conveyed via a pipeline 42 to one or more compressors 16a, 16b arranged in parallel. In order to allow the gas flow to be delivered to several compressors 16a, 16b in parallel, the pipeline 42 has one or more multi-directional lines leading to pipelines provided with valves 143, 243. Multi-way connections 43 are provided. In Fig. 2 the gas flow is delivered only through one of the two compressors 16a, 16b. However, it can be envisioned that the gas flow passes through both compressors (16a, 16b) in parallel according to the reference flow rate for supplying the energy-production equipment (4 or 6). have.

For example, the compressors (16a, 16b) are multi-stage compressors that allow the gas flow to be heated and compressed at a pressure compatible with the specifications of the energy-producing equipment 6 through which natural gas is supplied, The pressure, for example, is an absolute pressure of 5 to 6 bar absolute in the case of combustion engines of the DFDE type. The compressors 16a and 16b are positive-displacement compressors, centrifugal compressors, or any other type of compressor compatible with the supply pressure at the inlet side of a combustion engine, fuel cell or gas turbine. I can.

Advantageously, the system 3 has an anti-surge protection device for protecting the compressors 16a, 16b against speeds having a small volumetric flow rate on the inlet side. Is equipped. Such an arrangement comprises a recirculation loop 44 on the outlet side of the compressors 16a, 16b, which recirculation loop allows a portion of the compressed gas flow to be returned upstream of the compressor 16. The recirculation loop 44 is provided with valves 18a and 18b that enable control of the flow rate in the recirculation loop 44. In the illustrated embodiment, the recirculation loop 44 is connected to the pipeline 14, and the configuration of the pipeline 14 will be described below.

Upon exiting the compressor(s) 16a, 16b, the gas stream is directed to a cooling apparatus 19 that allows the temperature of the gas stream to be brought to a reference temperature. When the system includes several compressors (16a, 16b) in parallel, the outlets of the compressors (16a, 16b) are connected to the inlet of the cooling mechanism (19) via three-way connections (45, 63). do.

Finally when leaving the cooling mechanism 19 the gas stream is conveyed via pipeline 46 to the energy-producing equipment 6 of the generator. The pipeline 46 is provided with a three-way connection 47, and in the two outlet paths of the three-way connection, the gas flow is directed toward the energy-producing equipment 6 of the generator and/or the propulsion. It is noted that valves 147, 247 are provided which allow them to be selectively directed towards the unit's energy-producing equipment 4.

It is also noted that in the illustrated embodiment, the main circuit supplied to the energy-producing equipment 4 of the propulsion unit is not equipped with a compressor unlike the sub circuit, because the main circuit and the suction of the main circuit This is because the pump 8a feeding the pipeline 7a can supply a pressure that meets the operating conditions of the energy-producing equipment 4.

3 shows the delivery of the gas through the sub-circuit when the natural gas evaporated in the storage tank is incorporated into a sub-supply circuit that feeds the energy-production equipment 6.

To do this the system 3 comprises a pipeline 71 which is opened into the upper part of the tank 2. The three-way connection part 70 connects the pipeline 71 opened into the upper part of the tank 2 to the sub-circuit through a pipeline 48 equipped with a valve 170, and the valve 270 It is provided and connected to the pipeline 49 which forms part of the heating circuit, the purpose of which will be detailed below. The three-way connection part 70 and the valves 170 and 270 form a switchable three-way connection member.

In addition, the pipeline 48 is connected to the pipeline 14 via a three-way connection 50. The three-way connection part 50 connects the pipeline 14 to a pipeline 51 provided with a valve 150 and forming a part of the heating circuit, and the pipeline provided with the valve 170 ( 48). The three-way connection part 50 and the valves 150 and 170 also form a switchable connection member. The pipeline 14 is connected to the sub-circuit via a three-way connection part 54, and the three-way connection part 54 is the outlet of the atomizer 10b and the pipeline 14 is connected to the atomizer. (31) to be connected to the inlet. Therefore, the gas evaporated in the tank 2 is introduced into the gas stream leaving the forced evaporation facility 9b before being transported to the second atomizer 31, and the second atomizer 31 is also liquefied. It has a function of controlling the temperature of the gas stream entering the phase separator 11b by spraying the natural gas of the gas into the gas stream. Accordingly, the sub-supply circuit includes, at an upstream of the sub-supply circuit, a path for delivering the evaporated natural gas collected in the tank 2, and a path for forced evaporation of the natural gas.

Such a route for conveying the evaporated gas in the tank is particularly suitable when the liquefied natural gas is stored at ambient temperature which results in a considerable natural evaporation.

In FIGS. 4 and 5 a path for supplying natural gas to the burner 5 is shown. 4 shows the path of forced evaporation of natural gas, while FIG. 5 shows the path of evaporated natural gas collected in the tank 2. It will be noted that in both cases the circuit for supplying the burner 5 bypasses the phase separator 11b so that the energy contained in the heavy fraction of the natural gas can be recovered.

In Fig. 4, the circuit feeding the burner 5 includes a circuit part common to the sub-circuit. This circuit part jointly enables the forced evaporation of the liquefied natural gas and is fed by the pump 8b, the suction pipeline 7b, the forced evaporation plant 9b and the atomizer as an option ( 10b).

Downstream of the forced evaporation facility 9b, the treatment and delivery system 3 connects the outlet of the forced evaporation facility 9b to a series of pipelines 38, 39, 40 equipped with a valve 155 A three-way connecting portion 55, and a valve 255 is provided with a pipeline 56, and a series of pipelines 38, 39, 40 lead to the phase separator 11b, The pipeline 56 allows the phase separator 11b to be bypassed so that the heavy fraction of the natural gas can be recovered and used in the burner 5. The switchable connecting member thus formed allows the outlet from the forced evaporation facility 9b to be selectively transferred to the phase separator 11b or toward the burner 5.

The pipeline 56 carries the gas stream leaving the forced evaporation facility towards the gas heating device 57. For example, the gas heating device 57 is a gas/liquid or gas/gas heat exchanger. Here, the gas heating device 57 is provided with a recirculation loop 58. The gas heating device 57 allows the gas phase to be heated to a reference temperature typically around 30°C upstream of the burner 5. Pipelines 68 and 59 at the outlet from the gas heating device 57 carry the gas towards the burner 5.

In Fig. 5, the supply circuit feeding the burner 5 includes another circuit part in common with the sub-circuit. This part of the circuit makes it possible to collect, in common, the evaporated natural gas in the tank 2. This part of the circuit jointly consists of a pipeline 71 open into the upper part of the tank 2, a pipeline 48 connected to the pipeline 71 by a three-way connection 70, and a three-way connection. It comprises a pipeline 14 connected to the pipeline 71 by 50. In addition, the pipeline 14 is connected to a three-way connection 60, the three-way connection 60 is to direct the pipeline 14 toward the phase separator 11b and the valves 143, 243 It is connected to a series of pipelines 39 and 40 that are connected toward the bar and is connected to a pipeline 56 equipped with a valve 160, and the pipeline 56 recovers the heavy fraction of the natural gas. This allows the phase separator 11b to be bypassed so that it can be used in the burner 5.

Thereafter, as detailed above in conjunction with FIG. 4, after the pipeline 56 conveys the gas flow towards the gas heating device 57, the pipelines at the outlet of the gas heating device 57 ( 68, 59) conveys the gas towards the burner 5.

Although the path of natural gas evaporated in the tank 2 and the path of forced evaporation of natural gas are shown in two different drawings for ease of understanding, these two paths above for transporting natural gas to the burner 5 It is noted that it is entirely possible to use them simultaneously.

Advantageously, the natural gas treatment and delivery system 3 is equipped with a device for monitoring a parameter representing the methane number of the delivered liquefied natural gas. The methane number represents the ability of a gaseous mixture to withstand undesirable knocking, and is included between 0 and 100. The methane number depends on the composition of the natural gas. The methane number for pure methane is 100. The methane number decreases as the proportion of heavier hydrocarbons such as propane and/or butane and/or pentane increases.

Such a device for monitoring a variable representing the methane number of the natural gas is, in particular, arranged downstream of one or both of the phase separators 11a, 11b to measure the flow rate of the gas flow of the light fraction of natural gas. , For example, one or more flow meters disposed within the pipeline 42. This flow rate represents the methane number of the delivered liquefied natural gas. This is because under steady state conditions at a constant pumping flow rate, as the tank 2 becomes empty and as the concentration of heavy hydrocarbons increases, this flow rate will tend to decrease.

As an alternative or in addition, it is likewise possible to place a temperature sensor in the pipeline 48, for example for delivering the evaporated gas collected in the tank, to measure the temperature of the evaporated gas collected in the tank 2 . This is because the higher the temperature of the evaporated gas, the higher the proportion of heavy hydrocarbons contained in the tank is closer to the end of the voyage.

In addition, as an alternative or additionally, it is also possible to log the purging frequency of at least one of the condensate collection containers 72a, 72b, and/or the level of the condensate of at least one of the containers 72a, 72b. It is equally possible to monitor how this evolves.

The monitoring device also includes a control unit capable of receiving and processing data collected by at least one of the sensors mentioned below. The control unit compares the variable(s) representing the methane number against a threshold value. Based on this comparison, the control unit may generate an alarm or the natural gas from the mode of operation in which natural gas is fed to the propulsion unit and/or the energy-producing equipment (4, 6) of the generator. The heavy fraction of the can be recovered and automatically switched to the mode of operation which is conveyed to the burner 5 of the energy production facility. In practice, when the variable representing the methane number is a methane number less than about 80, the control unit generates an alarm or automatically switches to the mode in which the heavy fraction of the natural gas is recovered and used.

In embodiments where such automatic switching of the mode of operation is foreseen, the monitoring device generates a reference signal in order to divert the gas flow to the burner 5 bypassing the phase separator 11b. It may transmit to one or more valves 155, 255, 160, 143, 243 provided in the three-way connecting parts 55 and 60.

The combustion engine of the propulsion unit when the energy-producing equipment is a hybrid combustion engine operating on gas/diesel, and in parallel with this, the heavy fraction of the natural gas is recovered and converted to an operating mode that is conveyed to the burner 5 (4) and/or the engine of the generator 6 is switched to diesel mode to continue propulsion of the vessel and/or to generate electricity.

In FIG. 6 the path of the natural gas is shown when a method for enabling heating of the tank 2 is carried out. This method is carried out when the tank 2 is almost empty, at which time the residual natural gas is in gaseous form in the tank 2.

During the implementation of the heating method, the natural gas is collected in the lower part of the tank 2 by means of a pipeline 52 that opens to the lower part of the tank 2.

In the illustrated embodiment, the pipeline 52 opened to the lower part of the tank 2 is connected to a switchable three-way connecting member 53, the switchable three-way connecting member 53 optionally, The pipeline 52 is connected to the pipeline 51 upstream of the heating circuit so that the gas flow can be collected in the lower part of the tank 2, or the liquefied natural gas from the onshore storage tank ( 2) so that the pipeline 52 is connected to a charging circuit 61 for filling the tank 2.

In addition, the pipeline 51 at the upstream portion of the heating circuit is connected to a three-way connection 50 at the downstream. The valves 170 and 150 are either a pipeline 48 enabling delivery of the evaporated gas collected in the tank 2, or a pipeline 14 of a pipeline 51 upstream of the heating circuit. ).

Accordingly, the upstream portion of the heating circuit will be connected to the inlet of the compressors 16a, 16b by the pipelines 39, 40 and 42 to convey the gas collected in the lower portion of the tank to the compressors. I can. The temperature of the gas stream leaving the compressors 16a, 16b for the implementation of the method of heating the tank 2 is, for example, a temperature in the range of 50°C.

Accordingly, the portion of the circuit comprising at least one of the pipelines 14, 39, 40 and 42 and the compressors 16a, 16b transfers gas to the energy-producing equipment 4, 6, and the heating It is common with the sub-circuit supplied to the circuit. As a result, the design of the system 3 for processing and delivering gases is optimized, and at least one of the compressors 16a, 16b prepares the gas flow for supply to the energy-production equipment 4, 6 While doing, it also relates to carrying out a method of heating the tank 2.

At the outlet from the compressors 16a, 16b, the three-way connections 62, 63 connect the outlets of the compressors 16a, 16b to the pipelines 64, provided with valves 162, 163, 65), and are provided with valves 262 and 263 and connect to pipelines that are open toward the sub-supply circuit. The pipelines (64, 65) are connected to the pipeline (56) via three-way connecting portions (66, 67), the pipeline (56) of the supply circuit feeding the burner (5). It forms part and leads to the gas heating device 57.

Accordingly, the gas flow passes through both the compressors 16a, 16b and the heating device 57 to heat the tank 2. When leaving the gas heating device 57, the gas flow has a temperature in the range of, for example, 80°C.

In addition, when leaving the gas heating device 57, the pipeline 68 leads to a three-way connection 69, which means that the excess part of the flow is reduced to the valve 169. ) Can be removed by the burner 5 through the pipeline 59, and another part of the gas flow to the tank 2 through the pipeline 49 provided with a valve 269 To enable return, the pipeline 49 forms a return portion leading to the tank 2.

Therefore, the pipeline 56, the gas heating device 57, and the pipeline 68 are a circuit common to the heating circuit for heating the tank 2 and the supply circuit for supplying gas to the burner 5 It will be understood that the part is limited. As a result, the pipelines (64, 65) are at the outlet of the compressors (16, 16b) in a circuit part common to the tank (2) heating circuit and the supply circuit for supplying gas to the burner (5). Form the connecting parts that allow the connection to be made.

The pipeline 49 forming a return portion leading to the tank 2 is connected to the upper portion of the tank 2 via the three-way connecting portion 70 by a pipeline 71 open. Therefore, depending on the position of the valves 170 and 270, the pipeline 71 opened to the upper part of the tank 2 is natural to the energy-producing equipment 4, 6 or the burner 5 It can be used to collect the evaporated gas in the tank 2 when it is desired to supply gas, or it can be used to inject hot gas when it is desired to heat the tank 2 .

As a result, during the implementation of the method for heating the tank 2, hot gas is injected into the upper part of the tank 2 while the gas is extracted from the lower part of the tank 2. As the hot gas tends to rise to the top of the tank 2 by nature, such a configuration makes it possible to obtain a thermal stratification of the tank 2, thereby making the tank ( 2) increase the efficiency of heating method.

In a manner known per se, as shown in FIG. 7 the loading pipeline/discharging pipeline is by sea or port by means of connectors suitable for transporting LNG cargo from or to the tank (2). Can be connected to the terminal.

7 shows an example of a marine terminal comprising a liquefied natural gas supply station 82, an underwater pipe 83, and an onshore facility 81. The liquefied natural gas supply station 82 is a stationary onshore installation comprising a mobile arm 84 and a tower 85 supporting the mobile arm 84. The movable arm 84 supports insulated flexible hoses 80 that can be connected to the loading pipelines. The orientable mobile arm 84 is suitable for ships of all sizes. A connection pipe, not shown, extends upwardly into the tower 85. The liquefied natural gas supply station 82 allows the tank of the vessel 1 to be filled from the onshore facility 81. The onshore facility includes liquefied gas storage tanks 86 and connecting pipes 87 connected to the liquefied natural gas supply station 82 by means of the underwater pipe 83. The underwater pipe 83 allows the liquefied gas to be transferred between the liquefied natural gas supply station 82 and the onshore facility 81.

In order to generate the pressure required to transport the liquefied gas, the pumps in the ship 1 and/or the pumps provided in the onshore facility 81 and/or the loading and unloading station 82 The use of pumps is made.

Although the present invention has been described with several specific embodiments, the present invention is not limited to those specific embodiments in any way, and all technical equivalents and combinations thereof that fall within the scope of the invention of the means by which the invention has been described. It is very obvious that it includes.

In particular, although in the embodiments described above the vessel comprises only one liquefied natural gas storage tank, it is likewise possible for the gas treatment and delivery system to be connected to a plurality of storage tanks. In that case each of the storage tanks is provided with suction pipelines fed from the pumps, and pipelines open into the upper and lower portions of the tank, which are treated with treatment system circuits as described above. system circuits).

Further to be noted, while the term connecting member was used above to describe a combination of several valves with a three-way connection and one or more incoming pipelines or one or more outgoing pipelines, the term Technical equivalents that allow incoming pipelines to be connected to one outgoing pipeline or one incoming pipeline to be connected to two outgoing pipelines, from one of the two incoming pipelines depending on the situation. To promote the flow or flow towards one of the two outgoing pipelines, or to allow the incoming flow to be split between the two outgoing flows, or to combine the two incoming flows into one outgoing flow. It extends to all technical equivalents equipped with means by which the choice to be made can be made.

The verbs "include", "have" or "have" and their conjugated forms do not exclude the presence of elements or other steps other than those listed in the claim. The use of the indefinite article "one" or "one" in an element or step does not exclude the presence of a plurality of such elements or steps unless otherwise stated.

Any reference signs placed between parentheses in the claims should not be construed as implying limitations on the claim.

Claims (13)

As a system for processing and delivering natural gas:
-A supply circuit that feeds energy-producing equipment selected from combustion engines, fuel cells or gas turbines, where natural gas is delivered from the liquefied natural gas storage tank (2) to the energy-producing equipment (4, 6). A supply circuit, comprising: an upstream portion connected to the tank 2 and a downstream portion connected to the energy-production equipment 4,6;
-A burner supply circuit allowing the delivery of natural gas from the tank 2 to the burner 5 and comprising an upstream part connected to the tank 2 and a downstream part connected to the burner 5; And
-A heating circuit for heating the tank 2, capable of collecting a gas flow from the lower part of the tank 2 and injecting the gas flow into the upper part of the tank 2, A heating circuit comprising an upstream portion connected to the pipeline 52 opened into the lower portion and a downstream portion connected to the pipeline 71 opened into the upper portion of the tank 2;
-Said energy-production equipment supply circuit and said heating circuit comprise a part of a circuit in common comprising a compressor (16a, 16b), said compressor having an inlet and an outlet, the pressure of the gas flow and Allowing the temperature to be increased, the circuit part being switchable upstream by a first three-way connection member (50, 150, 170) and a second three-way connection member (62, 162, 262) switchable downstream; 63, 163, 263, and the switchable first three-way connecting member comprises the upstream portion of the energy-production equipment supply circuit or the upstream portion of the heating circuit, the compressor (16a, 16b) And the switchable second three-way connection member allows the outlet of the compressor to be selectively connected to the downstream portion of the energy-producing equipment supply circuit or the downstream portion of the heating circuit. And;
-The downstream portion of the heating circuit includes a third three-way connecting member 69, and the third three-way connecting member removes a part of the gas flow that is transferred to the burner 5 in the heating circuit. Natural gas treatment and delivery system, in order to make it possible to connect said downstream part of said heating circuit to said downstream part of said supply circuit feeding said burner (5). The method of claim 1, wherein the downstream portion of the heating circuit comprises a connection section (64, 65) for connection to the outlet of the compressor and a return section (49) leading toward the tank (2). Wherein the heating circuit and the downstream portion of the burner supply circuit jointly include a portion including a gas heating appliance 57, the gas heating appliance having an inlet and an outlet, the portion Jointly bounded by a fourth three-way connection member (66, 67, 160, 162, 163) switchable upstream and by the third three-way connection member (69, 169, 269) downstream, the The switchable fourth three-way connecting member is the gas heating device at the upstream portion of the burner supply circuit 5 or at the outlet of the compressor 16a, 16b of the heating circuit. It is possible to selectively connect to the inlet of 57, the third three-way connecting member, the outlet of the gas heating device 57 is to the downstream portion of the burner supply circuit, and the tank return portion of the heating circuit (return-to-tank section; 49), a natural gas treatment and delivery system. The method according to claim 1 or 2, wherein the natural gas treatment and delivery system comprises a switchable three-way connection member (70, 170, 270), the switchable three-way connection member (70, 170, 270) The pipeline 71, which is open into the upper part of the tank, can on the one hand be injected into the upper part of the tank 2 so that the downstream part of the heating circuit, or on the other hand the It can be selectively connected to the upstream part of the supply circuit and/or the upstream part of the burner supply circuit which feeds the energy-producing equipment (4, 6) so that the vaporized gas in the tank (2) can be collected. And natural gas treatment and delivery systems. 3. The tank (2) according to claim 1 or 2, comprising a tank filling circuit (61) and a switchable three-way connection member (53), the switchable three-way connection member (53) In the upstream part of the heating circuit, or on the other hand, the pipeline 52 open into the lower part of the tank 2 so that a gas flow can be collected in the lower part of the tank 2 A natural gas treatment and delivery system that allows it to be selectively connected to a charging circuit. The method of claim 1 or 2, wherein the energy-producing equipment supply circuit comprises a phase separator (11a), the phase separator downstream, on the one hand, having the longest carbon chain. It is connected to a return pipe (12a) which allows a heavy fraction of natural gas containing hydrocarbons to be returned to the tank (2) in the form of condensate, on the other hand hydrocarbons having the shortest carbon skeleton. A natural gas treatment and delivery system connected to a pipe (42) connected to the inlet of the compressor (16a, 16b) to conduct a light fraction of natural gas comprising a flow. 6. The natural gas treatment and delivery system according to claim 5, wherein the burner supply circuit (5) bypasses the phase separator (11a). The natural gas treatment and delivery system according to claim 1 or 2, wherein the compressor (16a, 16b) is a multistage compressor. The system according to claim 1 or 2, wherein the natural gas treatment and delivery system comprises a compressor protection device, the protection device comprising a recirculation loop (44) equipped with a valve (18a, 18b), the valve ( 18a, 18b allows the gas flow collected downstream of the compressors (16a, 16b) to be returned upstream of the compressors (16a, 16b). 3. A circuit according to claim 1 or 2, wherein the supply circuit for feeding the energy-producing equipment (4, 6) and the circuit part common to the heating circuit comprises a plurality of compressors (16a, 16b) arranged in parallel. Including, natural gas treatment and delivery system. Energy production equipment equipped with liquefied gas storage tanks (2), energy-producing equipment (4, 6) selected from combustion engines, fuel cells and gas turbines (4, 6) as energy-producing equipment, and burners (5). production installation), and the natural gas treatment and delivery system according to claim 1 or 2. The ship according to claim 10, wherein the energy-producing equipment (4, 6) is for propulsion of the ship. A method of filling a tank of a ship (1) according to claim 11, wherein the fluid is transferred from a floating storage facility or an onshore storage facility (81) through insulated pipelines (80) to the ship (1). ) Of the tank (2) is delivered, the ship tank filling method. As a fluid transfer system, the system comprises: the ship (1) according to claim 11, and the tank (2) installed in the hull of the ship to be connected to a floating storage facility or an onshore storage facility (81). Pipelines (80), and a pump for driving a stream of fluid from the floating or onshore storage facility through the insulated pipelines to the tank of the ship.

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