Patent Grant
11549646
This application is a § 371 of International PCT Application PCT/FR2017/051964, filed Jul. 19, 2017, which claims § 119(a) foreign priority to French patent application FR 1658258, filed Sep. 6, 2016.
The present invention relates to a facility for storing and cooling a liquefied gas, for example, a liquefied natural gas. Furthermore, the present invention relates to a storage method for storing a liquefied gas.
A facility for storing liquefied natural gas is known from document U.S. Pat. No. 3,302,416 A that allows the liquefied natural gas to be stored while it is transported to another building. The cooling device disclosed in document U.S. Pat. No. 3,302,416 A comprises a plurality of compressors, a plurality of engines, and a plurality of heat exchangers configured to cool the liquefied gas coming from the tank and at least one refrigeration source outside the gas storage facility. The refrigeration source corresponds to an item of equipment that is independent relative to the compressors, exchangers, etc. forming the storage facility and allows limited amounts of stored liquefied gas to be sub-cooled in order to be able to avoid a heat gain in said facility and allows the sub-cooled liquid to be reinjected into various zones of the storage space so as to provide relatively uniform temperature conditions in the stored liquid gas with minimal disruption from vapors stratified on the liquid surface. This refrigeration source can be, for example, a container in the form of a cylinder of gas, called cycle gas.
However, the storage facility disclosed in this document comprises numerous independent components, which require numerous mutual interconnection interfaces. Furthermore, these numerous components form a large buffer volume that needs to be filled upon each start-up of each cycle. The use of an internal system enables the cycle gas that is used to operate the facility to be stored, said cycle gas being stored in another item of external equipment when it is hot and being reintroduced into the circuit of the facility once it is cool.
Furthermore, in this document, only the transport function is highlighted, there is no reference to the loading and unloading of the liquefied gas. Indeed, this document simply discloses that when the liquefied gas is transported they ensure that the pressure does not increase and therefore everything that evaporates is reliquefied. However, there is no mention of the unloading of said gas once it has reached its destination.
Liquefaction of natural gas makes its marine transportation conceivable and viable. During shipping, under the effects of thermal ingress in the storage units and of buffeting phenomena, large amounts of gas are generated by evaporation. In order to control the resulting pressure fluctuations, this evaporated gas either can be used for propulsion or can be burnt by a flare or can be reliquefied. Any transfer of liquid to a storage unit in which the pressure and temperature conditions differ from those of the original storage unit leads to the evaporation of the liquefied natural gas, for temperature (hot tank) and/or pressure (flashing of the liquid) reasons. This scenario occurs in the following situations: transfer from a supply vessel to a client, filling of a methane carrier at the terminal, refrigeration of the storage units at the end of the unladen return voyage of a methane carrier.
In particular, the aim of the present invention is to fully or partly overcome the aforementioned problems.
The present invention can involve using a facility that is particularly disclosed in document WO 2009/066044 and for which all the features are incorporated by reference in the present application. The facility can comprise at least: one cryogenic device intended to transfer heat from a cold source to a hot source via a working fluid or a cycle gas circulating through a working circuit or through a closed cycle circuit, the working circuit comprising the following in series: a portion for isothermal, or substantially isothermal, compression of the fluid, a portion for isobaric, or substantially isobaric, cooling of the fluid, a portion for isothermal, or substantially isothermal, expansion of the fluid and a portion for isobaric, or substantially isobaric, reheating of the fluid. The compression portion comprises at least two compressors disposed in series, at least one exchanger for cooling compressed fluid disposed at the output of each compressor. The expansion portion comprises at least one expansion turbine and at least one exchanger for reheating expanded fluid, with the compressors and the one or more expansion turbine(s) being driven by at least one engine, called high-speed engine. The engine comprises an output shaft, one of the ends of which supports and sets into rotation a first compressor by direct coupling and the other end of which supports and sets into rotation a second compressor or an expansion turbine by direct coupling.
In the present invention, a “high-speed engine” is understood to be an engine typically running at a rotation speed of 10,000 revolutions per minute or several tens of thousands of revolutions per minute. A low-speed engine instead runs at a speed of a few thousand revolutions per minute.
The aim of the invention is a facility for storing and cooling a liquefied gas, for example, a liquefied natural gas, the facility comprising:
the engine being mechanically connected, on the one hand, to the compressor in order to drive the compressor and, on the other hand, to the turbine so that the turbine drives the engine,
the facility being characterized in that it comprises at least one connection line configured to recover a liquefied gas to be cooled from at least one remote container, which is separate and independent from the facility, said connection line being fluidly connected to the tank of the facility.
By virtue of this configuration of the facility and particularly due to the closed and autonomous cooling circuit, a buffer volume is not required for storing cycle gas, which reduces the total fluid capacity of the circuit. Indeed, in this configuration, cooling is performed initially: the cycle gas is already at a determined and over-designed pressure in all the items of equipment of the cooling circuit.
Furthermore, this configuration is compact and space-saving, as the distance between the items of equipment of the cooling circuit is not significant. This reduced distance allows a reduced amount of cycle gas to be used and therefore avoids having to excessively increase the pressure in order to cool down to reach an operating pressure. Furthermore, as the turbine is mechanically connected to the compressor by means of the engine, the facility can operate with a single compressor, which reduces the size of the facility and the fluid connections between the various items of equipment of the cooling circuit.
Furthermore, the connection line allows cooling of a liquefied gas to be cooled that comes from a container, which is separate and independent from the facility.
In the present application and according to the invention, the term “container, which is separate and independent from the facility” will be understood to mean a container that does not form part of the facility or of the cooling circuit, for example, the container is on the same vessel, on another vessel or on land.
Moreover, the cooling device does not require valves between the compressor and the turbine, since the speed of the engine simply needs to be controlled and commanded in order to regulate the flow of coolant circulating through the first heat exchanger. Thus, the facility is particularly quick to install and commission, which is particularly advantageous when the facility must be installed on a liquefied gas transport vehicle, for example, on a vessel such as a methane carrier.
When the facility is in operation, the first heat exchanger allows liquefied gas coming from the tank to be cooled, via the cycle gas, to a temperature that is below the temperature of the liquefied gas contained in the tank. This cooling is commonly denoted “sub-cooling”.
According to one feature of the invention, the facility comprises at least one bypass pipe connected to the injection pipe, said bypass pipe being configured to transfer some of the cooled liquefied gas to a remote container, which is separate and independent from the facility.
This allows at least one container, which is separate and independent, to be supplied for the use of cooled liquefied gas.
According to one feature of the invention, the supply line is at least partly coincident with the bypass pipe. Alternatively, the supply line is separate from the bypass pipe.
According to another feature of the invention, the engine is directly connected to the compressor.
According to another feature of the invention, the engine is directly connected to the turbine.
According to one feature of the invention, the facility further comprises a pump configured to supply the cooling device with liquefied gas in the liquid state coming from the tank. In other words, the cooling circuit is fluidly connected to the pump.
According to one feature of the invention, the pump is arranged in the lower region of the tank.
According to one feature of the invention, the output of the turbine is directly fluidly connected to the first heat exchanger.
According to one feature of the invention, the output of the compressor is indirectly fluidly connected to the first heat exchanger.
According to one feature of the invention, the cooling circuit further comprises a second heat exchanger configured to generate a heat exchange between the compressed cycle gas coming from the compressor and the expanded cycle gas coming from the turbine.
According to one feature of the invention, the input of the compressor is fluidly connected to the output of the turbine without an intermediate component other than the first heat exchanger and the second heat exchanger.
According to another feature of the invention, the turbine is fluidly connected to the first heat exchanger by a first connection pipe, without an intermediate component.
According to another feature of the invention, the compressor is fluidly connected to the first heat exchanger by a second connection pipe.
According to one feature of the invention, the cooling circuit comprises at least one first connection component mechanically connecting the engine to the compressor, and at least one second connection component mechanically connecting the engine to the turbine.
According to another feature of the invention, the first connection component comprises a first rotary shaft.
According to another feature of the invention, the second connection component comprises a second rotary shaft.
According to one feature of the invention, the cooling circuit is configured to operate on the basis of a Brayton cycle. In the present application, “Brayton cycle” will be understood to mean a thermodynamic cycle developed by George Brayton that generates a gas, which in the present invention is called cycle gas.
According to one feature of the invention, the cooling circuit comprises a third heat exchanger configured to generate a heat exchange between the cycle gas and a fluid at ambient temperature, for example, water or a coolant, which allows the heat from the cycle gas to be discharged outwards.
According to one feature of the invention, the injection component is arranged in the upper region of the tank. In other words, the injection component injects the cooled liquefied gas in the vapor phase, i.e. above the level of the liquefied gas in the liquid state.
By way of a variation, the injection component is arranged in the lower region of the tank. In other words, the injection component injects the cooled liquefied gas in the liquid phase, i.e. below the level of the liquefied gas in the liquid state.
According to one feature of the invention, the injection component comprises a plurality of injection nozzles arranged in series and/or in parallel.
According to one feature of the invention, the cooling circuit is configured to cool liquefied gas coming from the tank to a temperature between 35 K and 150 K, for example, equal to 110 K or 80 K.
According to another feature of the invention, the cooling circuit is configured to cool liquefied gas coming from the tank at a flow rate between 5 m3/h and 50 m3/h.
According to one feature of the invention, the tank contains a liquefied gas selected from the group formed by a liquefied natural gas, or another methane-rich gas such as biomethane, nitrogen, oxygen, argon and mixtures thereof.
According to one feature of the invention, the cooling circuit contains a coolant selected from the group comprising nitrogen, argon, neon, helium and mixtures thereof.
According to one feature of the invention, the bypass pipe comprises a terminal end comprising a connector intended to be connected to a remote container.
According to one feature of the invention, the bypass pipe preferably comprises a valve, in particular an isolation valve.
A further aim of the invention is a method for using a facility according to the invention for a liquefied gas, for example, a liquefied natural gas, the method comprising at least the following steps:
According to one feature of the invention, the method comprises a transfer step performed after the injection of the cooled liquefied gas, the transfer step comprising transferring at least some of the cooled liquefied gas to at least one remote container, which is separate and independent from said facility, by means of the injection pipe and the bypass pipe of the facility.
Advantageously, the transfer of the liquefied gas can be partial or total depending on the number of tanks of the facility and depending on the requested amount of cooled liquefied gas.
According to one feature of the invention, the facility that is used comprises at least two tanks configured to contain liquefied gas, said method according to the invention being implemented during a journey, in the course of which the tanks are full.
Following delivery, at least one tank can be empty (empty or practically empty of liquid).
According to one feature of the invention, the method comprises an additional step of refrigerating the at least one empty tank of the facility or one or more other empty container(s) of at least one other facility, the refrigeration step comprising:
This means that, particularly for the purposes of a journey of the facility (on a ship), instead of keeping one or more tank(s) empty, liquefied gas is transferred from a non-empty tank to one or more other empty tank(s), particularly to keep them cool.
Advantageously, this refrigeration step is performed after unloading the liquefied gas and before the subsequent filling of the one or more tank(s) of the facility or of the one or more container(s) of at least one other facility.
Advantageously, this refrigeration step is performed continuously to avoid leaving the tanks empty and hot and to allow the thermal load to be equalized in order to limit any losses associated with the final vaporization peak of liquefied gas.
The advantage is to thus only maintain liquid in the tanks of a ship that enables the return voyage, without considering the cooling losses on arrival.
In the end, this allows the amount of liquid to be increased that is transported to the destination in the same ship.
According to one feature of the invention, the refrigeration step is performed during a journey, in the course of which at least one of the tanks is empty.
Furthermore, a further aim of the present invention is a transport vehicle, for example, a transport vessel, for transporting a liquefied gas, for example, a liquefied natural gas, the transport vehicle being characterized in that it comprises a facility according to the invention.
The embodiments and the variations mentioned above can be taken separately or according to any possible technical combination.
The invention will be better understood from the following description, which relates to embodiments according to the present invention, which are provided by way of non-limiting examples and are explained with reference to the accompanying schematic drawings, in which:
As shown in
Furthermore, and as shown in
According to a variation of the first embodiment shown in
For example, another tank 4 is shown as a dotted line in
Of course, in another variation (not shown), the bypass pipe 32 and the connection line 31 can be installed on the same facility.
As shown in
As can be seen in
The cooling circuit 10 further comprises a second heat exchanger 24 configured to generate a heat exchange between the compressed cycle gas 3 and the expanded cycle gas 3, as shown in
The cooling circuit 10 further comprises a third heat exchanger 26 configured to generate a heat exchange between the compressed cycle gas 3 and water or air or any other coolant coming from an external source.
In the event that one or more of the tank(s) 4 contain(s) liquefied natural gas on a vehicle, in particular a ship, the natural gas that vaporizes can be used as fuel for an engine of the vehicle and any excess gas is burnt in a flare, for example.
It can be seen that, according to the known facility (
Of course, the invention is not limited to the embodiments described and shown in the accompanying figures. Modifications are still possible, particularly in terms of the constitution of the various elements or by substitution of equivalent techniques, yet without departing from the scope of protection of the invention.
While the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art in light of the foregoing description. Accordingly, it is intended to embrace all such alternatives, modifications, and variations as fall within the spirit and broad scope of the appended claims. The present invention may suitably comprise, consist or consist essentially of the elements disclosed and may be practiced in the absence of an element not disclosed. Furthermore, if there is language referring to order, such as first and second, it should be understood in an exemplary sense and not in a limiting sense. For example, it can be recognized by those skilled in the art that certain steps can be combined into a single step.
The singular forms “a”, “an” and “the” include plural referents, unless the context clearly dictates otherwise.
“Comprising” in a claim is an open transitional term which means the subsequently identified claim elements are a nonexclusive listing i.e. anything else may be additionally included and remain within the scope of “comprising.” “Comprising” is defined herein as necessarily encompassing the more limited transitional terms “consisting essentially of” and “consisting of”; “comprising” may therefore be replaced by “consisting essentially of” or “consisting of” and remain within the expressly defined scope of “comprising”.
“Providing” in a claim is defined to mean furnishing, supplying, making available, or preparing something. The step may be performed by any actor in the absence of express language in the claim to the contrary.
Optional or optionally means that the subsequently described event or circumstances may or may not occur. The description includes instances where the event or circumstance occurs and instances where it does not occur.
Ranges may be expressed herein as from about one particular value, and/or to about another particular value. When such a range is expressed, it is to be understood that another embodiment is from the one particular value and/or to the other particular value, along with all combinations within said range.
All references identified herein are each hereby incorporated by reference into this application in their entireties, as well as for the specific information for which each is cited.
| Number | Date | Country | Kind |
|---|---|---|---|
| 1658258 | Sep 2016 | FR | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/FR2017/051964 | 7/19/2017 | WO |
| Publishing Document | Publishing Date | Country | Kind |
|---|---|---|---|
| WO2018/046809 | 3/15/2018 | WO | A |
| Number | Name | Date | Kind |
|---|---|---|---|
| 3302416 | Proctor | Feb 1967 | A |
| 10012350 | Le Bruchec et al. | Jul 2018 | B2 |
| 20020038676 | Siegele | Apr 2002 | A1 |
| 20060283206 | Rasmussen | Dec 2006 | A1 |
| 20090211262 | Lee et al. | Aug 2009 | A1 |
| 20100000253 | Fuchs | Jan 2010 | A1 |
| 20160216029 | Ragot | Jul 2016 | A1 |
| Number | Date | Country |
|---|---|---|
| 10 2013 081333 | Apr 2015 | DE |
| 102013018333 | Apr 2015 | DE |
| 1 682 814 | Jul 2006 | EP |
| 2 775 194 | Sep 2014 | EP |
| 3 028 306 | May 2016 | FR |
| 2013-87911 | May 2013 | JP |
| 2016-520771 | Jul 2016 | JP |
| 10-0875064 | Dec 2008 | KR |
| 10-1537277 | Jul 2015 | KR |
| 2009 066044 | May 2009 | WO |
| Entry |
|---|
| DE-102013018333-A1 Translation. |
| International Search Report and Written Opinion for corresponding PCT/FR2017/051964, dated Nov. 10, 2017, English translation. |
| French Search Report and Written Opinion for corresponding FR1658258, dated May 5, 2017. |
| Number | Date | Country | |
|---|---|---|---|
| 20190257475 A1 | Aug 2019 | US |
