System for removing cryogenic liquefied gas from a ship's tank, related ship, use and method
The system addresses maintenance complexities and space constraints by using a collection container with differential pressure control to transfer liquefied gas externally, enhancing pump accessibility and reducing equipment volume and costs.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- TGE MARINE GAS ENG GMBH
- Filing Date
- 2025-12-17
- Publication Date
- 2026-06-25
AI Technical Summary
Existing systems for extracting cryogenic liquefied gas from ship tanks face challenges such as complex maintenance due to pumps being installed inside the tanks, susceptibility to contamination and clogging, limited service life, and difficulty in monitoring pump condition, as well as space constraints in tank connection compartments.
A system with a collection container connected to the extraction line outside the ship's tank, utilizing a differential pressure control device to manage pressure differences for transferring liquefied gas, eliminating the need for pumps inside the tank and simplifying maintenance by allowing easy access to pumps through a manhole.
This configuration reduces the volume of equipment in the tank connection compartment, facilitates easy pump maintenance, and lowers the number of pumps required, thereby reducing investment and operating costs while preventing large greenhouse gas releases.
Smart Images
Figure EP2025087769_25062026_PF_FP_ABST
Abstract
Description
[0001] Bremen, December 17, 2025 Our reference: TA 3044-02 WO CHA / pwa / fun / jga
[0002] Publisher / owner: TGE Marine Gas Engineering GmbH
[0003] Official file number: Subsequent registration
[0004] TGE Marine Gas Engineering GmbH
[0005] Mildred-Scheel-Straße 1, 53175 Bonn
[0006] System for extracting cryogenic liquefied gas from a ship's tank, ship in question, use and procedure
[0007] The invention relates to a system for extracting cryogenic and deep-freeze liquefied gas from at least one ship tank for a gas consumer, in particular as fuel for a ship propulsion system or for a cargo system, with an extraction line for extracting liquefied gas from the ship tank, wherein the extraction line extends into the ship tank.
[0008] As emission limits become stricter and the maritime industry strives to reduce pollutant emissions, systems are increasingly being developed that allow the propulsion and general operation of equipment on board merchant ships using so-called fuel gases, such as natural gas. For gas operation, it is necessary to store the appropriate fuel gas, also known as combustible gas, on board the ship. Due to the lower energy density of natural gas compared to heavy fuel oil, liquefied natural gas (LNG) is frequently used as the fuel gas, as it allows for a relatively high energy density in the tank volume at relatively low pressure and cryogenic temperatures. Furthermore, the use of alternative fuel gases is also known. This allows the required amount of energy to be provided within the limited space available on board a ship.
[0009] LNG-based gas supply systems typically include a loading system, also known as a bunkering system, a corresponding LNG storage facility in the form of one or more ship tanks, and equipment for fuel conveyance, pressure boosting, fuel conditioning, and safety systems. Furthermore, applications are known in which liquefied gas is transported in cargo tanks on board ships. These systems are also referred to as cargo systems. The task of these cargo systems is also to transfer liquefied gas from the cargo tanks, for example, for tank unloading or similar purposes.
[0010] To pump liquid fuel gas or cargo gas from the ship's tank, pumps, particularly submersible pumps, are used in the prior art and are located within the tank volume. However, the use of such submersible pumps has several disadvantages. Firstly, there is no free access to the pumps without first purging the tanks, as the pumps are installed inside the fuel tank. This makes maintenance work complex. Furthermore, such pumps are susceptible to contamination and clogging of the associated filter, which is also frequently located within the tank volume and, in one embodiment, at the pump's intake housing. In addition, the service life of such pumps is inherently limited, and it is difficult to monitor their condition when they are located within the tank volume.
[0011] In particular, tanks for merchant ships with gas fuel supply systems are often equipped with tank connection rooms in accordance with the applicable regulations, whereas in cargo systems the tank connections on deck are usually located on a tank dome.
[0012] In so-called LCO2 gas tankers, current technology typically installs several tanks on board. Due to the thermodynamic properties of LCO2, the pressure in the tanks must always be kept above the triple point to prevent the liquid from solidifying. For pure CO2, this point is approximately 5.2 bar. Therefore, only pressurized tanks are suitable for transporting LCO2. Some of these LCO2 tankers can also transport LPG. For larger transport volumes, current technology requires more than one tank, each equipped with at least one cargo pump for unloading the LCO2.
[0013] Furthermore, removing such pumps from tanks with tank connection compartments is complex, as a lifting device must be kept within the so-called tank connection compartment, which is located above the tank. Besides the use of submersible pumps, deepwell pumps are also known, but these can require a significant height in the tank connection compartment, resulting from the height of the pump, the motor, and the lifting device. Although these pumps can be serviced without first purging the tank, the available space for maintenance is still limited. In addition, regular maintenance is required, and the pumps may be suboptimal in terms of hydraulic performance at their design point.
[0014] The invention is therefore based on the objective of eliminating, as far as possible, the disadvantages found in the prior art. In particular, a system for extracting cryogenic and cryogenic liquefied gas from at least one ship tank was to be provided, in which the maintenance of the system is simplified and, moreover, the required volume of the tank connection space or the number of pumps installed in the ship tanks and the associated installations and nozzles on the tank are kept as low as possible.
[0015] The invention solves the problem described above with regard to the system by providing a collection container connected to the extraction line, wherein the collection container is arranged outside the ship's tank and is configured to extract the liquefied gas from the ship's tank via the extraction line, wherein the collection container has a differential pressure control device configured to control an internal pressure in the collection container such that it is lower than the internal pressure of the ship's tank in order to transfer the liquefied gas from the ship's tank to the collection container based on the pressure difference.
[0016] The invention utilizes the fact that such a configuration, namely providing the collection tank outside the ship's tank, avoids the need to arrange pumps inside the ship's tank. Furthermore, it has the positive effect of reducing the amount of equipment required within or on the tank connection compartment, thereby reducing the size, i.e., the volume, of the tank connection compartment or the tank dome in cargo systems. The collection tank is preferably located both outside the ship's tank and outside the tank connection compartment. However, it is also conceivable to install the collection tank within the tank connection compartment or on deck. According to one embodiment, the gas consumer is one or more of the following: ship propulsion, generator, steam generator, or fuel cell.
[0017] According to one embodiment, at least one of the following is stored or transported in the cargo tanks of the liquefied gas system: LNG, LPG, ethane, liquefied CO2 (LCO2). 2 ), propane, butane, ammonia.
[0018] According to one embodiment, the collection tank is designed as a pump tank and includes a pump configured to transfer the liquefied gas from the pump tank to the ship's propulsion system or a component of a cargo system, in particular wherein the collection tank has a tank opening, preferably a manhole, for replacing the pump. The collection tank can also have more than one pump.
[0019] A component of the cargo system can be, for example, a pipeline, a tank, or a shore-based facility. Emptying a ship's tank(s) can be done by transferring the cargo to one or more onboard tanks or by transferring it to a shore-based facility or another ship / barge.
[0020] This ensures that the pump is easily accessible via the tank opening or manhole should maintenance or replacement be required. Another advantage of this configuration is the very small volume of the collection / pump tank compared to the ship's fuel tank. Therefore, if the collection / pump tank needs to be opened, only a very small volume needs to be degassed. For this purpose, the liquefied gas can be transferred from the collection / pump tank to the ship's fuel tank by increasing the pressure. This also prevents large quantities of greenhouse gas from being released into the atmosphere. A spare pump can be carried on board the ship, which can replace the pump installed in the collection / pump tank during maintenance. This eliminates the need for redundancies, as maintenance and replacement are now performed using a single pump.Replacing the pump becomes relatively easy. In systems with more than one ship tank, the number of pumps required to transfer the liquefied gas can be reduced, resulting in lower investment and operating costs.
[0021] The pump is preferably a fuel gas pump. The liquefied gas is extracted from the
[0022] The pressure differential between the collection tank and the ship's tank transports the liquefied gas to the pump. The collection tank / pump tank is preferably located in the fuel preparation room or on deck. The pump tank's primary function is to achieve a sufficient net positive suction head (NPSH). This ensures that the pump, particularly the fuel gas pump, can operate. In one embodiment, the pump is a cargo pump designed to transfer liquefied gas loaded into the ship's tank(s).
[0023] According to an alternative embodiment, the system, in addition to the collection tank, has a pump tank with a pump which is designed to pump the liquefied gas from the pump tank to the ship's propulsion or a component of a cargo system, and wherein the pump tank is fluidly connected to the collection tank via a connecting line.
[0024] According to one embodiment, a first pressure sensor for measuring the internal pressure in the collection container is assigned to the collection container, and a second pressure sensor for measuring the internal pressure in the ship's tank is assigned to the ship's tank, with the pressure sensors being connected to the differential pressure control device via signal transmission. The pressure sensors enable pressure monitoring both within the collection container and within the ship's tank.
[0025] According to one embodiment, the collection tank is fluidly connected to a compressor system via a control valve, the differential pressure control device being configured to selectively open the first control valve to the compressor system in order to regulate the pressure inside the collection tank to a lower pressure than in the ship's tank. According to one embodiment, the compressor system is a BOG compressor system, in particular a vapor return compressor system of the ship. Alternatively, however, a separate compressor system can also be provided.
[0026] According to one embodiment, a ship's liquefied gas heating system is fluidly connected to the ship's tank via a control valve, wherein the differential pressure control device is configured to selectively open the valve and supply vaporized gas from the liquefied gas heating system to the ship's tank when a minimum differential pressure between the storage tank and the ship's tank is not maintained. In other words, to maintain the minimum differential pressure, vaporized gas, for example LNG, can be directed into a vapor space of the ship's tank. In this way, the pressure in the ship's tank, and thus also the differential pressure, can be increased. According to another embodiment, the ship's tank is fluidly connected to the compressor system via a control valve, wherein the differential pressure control device is configured to open the control valve when a maximum differential pressure between the storage tank and the ship's tank is exceeded, or when the maximum differential pressure is exceeded.The operating pressure of the ship's tank is opened to allow vaporized gas from the tank to be fed into the compressor system. This lowers the pressure inside the tank, thereby regulating the differential pressure between the collection tank and the ship's tank, as well as the pressure within the tank itself.
[0027] According to one embodiment, a control valve is associated with the extraction line, and a level control device is associated with the collection tank. This device is configured to control the fill level in the collection tank by actuating the control valve. According to another embodiment, a filter unit with a filter element is installed upstream of the pump housing on the inlet side. The filter unit is located outside the pump housing and / or the ship's tank and / or the tank connection compartment (if present) in such a way that the filter element can be replaced without opening the pump housing and / or the ship's tank and / or the tank connection compartment. This simplifies maintenance or replacement of the filter element. According to another embodiment, a filter system with multiple filter elements can be used. Such a filter system is also referred to as a duplex filter.
[0028] According to one embodiment, the ship's tank has a sump, which is formed in particular in the bottom of the ship's tank, with the extraction line extending into the sump. In this way, almost complete emptying of the ship's tank is achieved.
[0029] The invention has been described above with reference to a system for extracting cryogenic and cryogenic liquefied gas from a ship's tank. In a further aspect, the invention relates to a ship with a ship's tank, a gas consumer, in particular a ship's propulsion system, and a system for extracting cryogenic and cryogenic liquefied gas from the ship's tank. The invention solves the problem described above with respect to the ship by designing the system according to one of the aforementioned embodiments. The ship benefits from the same advantages and preferred embodiments as the system according to the invention, and vice versa. To avoid repetition, reference is made to the above statements, and their content is incorporated herein.In a further aspect, the invention relates to the use of a system according to one of the preceding embodiments for a ship, in particular for a ship or cargo system powered by one of the following liquefied gases: liquefied natural gas (LNG), ethane, liquefied petroleum gas (LPG), ammonia, LCO2. This use also takes advantage of the same benefits and preferred embodiments as the system and method according to the invention, and vice versa. To avoid repetition, reference is made to the above statements, and their content is incorporated herein.
[0030] In a further aspect, the invention relates to a method for extracting cryogenic and cryogenic liquefied gas from a ship's tank for a gas consumer, in particular as fuel for a ship's propulsion system or a cargo system. The method solves the aforementioned problem with the following steps: providing a collection container which is connected to a ship's tank via an extraction line; controlling the pressure in the collection container such that it is lower than the internal pressure of the ship's tank in order to transfer the liquefied gas from the ship's tank to the collection container based on the pressure difference.
[0031] This avoids the need to position a pump located in or adjacent to the collection container within the ship's tank or the tank connection compartment. Furthermore, the method also utilizes the same advantages and preferred embodiments as the system, ship, and use according to the invention, and vice versa. To avoid repetition, reference is made to the above statements, and their content is incorporated herein.
[0032] According to one embodiment, the collection container is a pump container which has a pump which is configured to pump the liquefied gas from the pump container to the ship's propulsion or a component of a cargo system, and wherein the pump container preferably has a container opening, in particular a manhole, for replacing the pump.
[0033] The method is further developed by the additional step of providing a pump tank with a pump configured to transfer the liquefied gas from the pump tank to the ship's propulsion system or a component of a cargo system. The method is further developed by connecting the ship's tank to a compressor system via a control valve, and the method includes the step of controlling, in particular reducing, the pressure inside the ship's tank by opening the control valve to the compressor system, especially when a maximum differential pressure between the storage tank and the ship's tank or a maximum operating pressure in the ship's tank is exceeded.
[0034] The method is further developed by connecting the ship's tank to a liquefied gas heating system via a control valve, the method comprising the step of: controlling, in particular increasing the pressure inside the ship's tank by opening the control valve to the liquefied gas heating system, especially when a minimum differential pressure between the collection tank and the ship's tank is undershot.
[0035] Depending on the design and arrangement of the ship's tank and fuel gas processing room, or the deck layout, the minimum differential pressure is, for example, 0.5 bar. According to one embodiment, the maximum differential pressure is 1 to 1.5 bar. This means that, compared to conventional systems, the required pressure in the ship's tank for conveying the fuel to the gas consumer is low. This avoids the risk of pressure fluctuations in the ship's tank, which can occur particularly in heavy seas. The starting pressure in the ship's tank can, if necessary, be adjusted by reducing the steam recirculation to the bunkering system so that the pressure in the ship's tank after bunkering is sufficient to start the fuel gas supply.
[0036] In other words, in a configuration with a pump reservoir and a collection tank, the system exhibits the following basic operating principle:
[0037] The LNG is preferably transferred from the fuel gas storage tank to a fuel gas pump located within or immediately adjacent to a pump housing in the fuel handling room, based on a pressure differential. The storage and pump housings serve to provide sufficient NPSH (Net Positive Suction Head) for the installed pump and ensure stable system control. The pressure in the pump housing is maintained at a low setpoint by a BOG compressor. The pressure in the fuel gas storage tank is maintained at a higher level compared to the pump housing. This is achieved by a differential pressure regulator, which receives input signals from the pressure transmitter in the pump housing and the pressure transmitter in the fuel gas storage tank and acts on the capacity control system of the BOG compressor.If the maximum differential pressure is exceeded, the pressure regulating valve of the fuel gas storage tank (BOG) releases pressure into the BOG compressor system. If the differential pressure is too low, vaporized LNG from the LNG heater / vaporizer is directed into the vapor space of the fuel gas storage tank. The liquid level in the pump housing is regulated by a level controller, which acts on a control valve in the liquid supply line. The system includes an accessible filter to protect the pump suction side. This filter is designed for the pump's suction flow rate and can be serviced without opening the fuel gas storage tank or the pump housing.
[0038] Since no pump is installed in the fuel gas storage tank, the usable LNG volume of the tank is increased because a low-level interlock for a tank pump is not required. This also facilitates the complete emptying of the fuel gas storage tank during operation before a shipyard stay (dry docking).
[0039] Only one pump is installed in the pump reservoir. A redundant pump is kept as a backup spare part in storage. Compared to conventional pressure build-up (PBU) services, as known from low-pressure fuel gas (FGS) systems, the pressure difference between the pump reservoir and the fuel gas storage tank is small. This avoids the risk of pressure fluctuations due to heavy seas.
[0040] The bunkering process is designed so that after the bunkering operation, the initial pressure in the tank is sufficient to fill the pump reservoir and start the fuel gas supply.
[0041] The invention is described below with reference to further exemplary embodiments as follows:
[0042] 1. Exemplary embodiment: System for extracting cryogenic and cryogenic liquefied gas from at least one ship tank for a gas consumer, in particular as fuel for a ship's propulsion system, comprising: an extraction line for extracting liquefied gas from the ship tank, wherein the extraction line extends into the ship tank, a pump container connected to the extraction line, characterized in that the pump container is arranged outside the ship tank and is configured to extract the liquefied gas from the ship tank via the extraction line, wherein the pump container has a differential pressure control device which is configured to control an internal pressure in the pump container such that it is lower than the internal pressure of the ship tank in order to transfer the liquefied gas from the ship tank into the pump container based on the pressure difference.
[0043] 2. Exemplary embodiment: The system according to exemplary embodiment 1, wherein the pump container has a pump which is configured to pump the liquefied gas from the pump container to the ship's propulsion, and wherein the pump container has a container opening, in particular a manhole, for replacing the pump.
[0044] 3. Exemplary embodiment: The system according to one of the preceding exemplary embodiments, wherein a first pressure sensor for measuring the internal pressure in the pump tank is assigned to the pump tank and a second pressure sensor for measuring the internal pressure in the ship tank is assigned to the ship tank, wherein the pressure sensors are connected to the differential pressure control device in a signal-conducting manner.
[0045] 4. Exemplary embodiment: The system according to one of the preceding exemplary embodiments, wherein the pump reservoir is fluidly connected to a compressor system via a control valve, and wherein the differential pressure control device is configured to selectively open the first control valve to the compressor system in order to regulate the pressure inside the pump reservoir to a lower pressure.
[0046] 5. Exemplary embodiment: The system according to exemplary embodiment 4, wherein the compressor system is a BOG compressor system of the ship.
[0047] 6. Exemplary embodiment: The system according to one of the preceding exemplary embodiments, wherein a liquefied gas heating system is fluidly connected to the ship's tank via a control valve, and wherein the differential pressure control device is configured to selectively open the control valve and supply vaporized gas from the liquefied gas heating system to the ship's tank when a minimum differential pressure between the pump container and the ship's tank is undershot.
[0048] 7. Exemplary embodiment: The system according to one of the preceding exemplary embodiments, wherein the ship's tank is fluidly connected to the compressor system via a control valve, and wherein the differential pressure control device is configured to open the control valve when a maximum differential pressure between the pump reservoir and the ship's tank is exceeded or when the maximum operating pressure in the ship's tank is exceeded, in order to supply vaporized gas from the ship's tank to the compressor system. 8. Exemplary embodiment: The system according to one of the preceding exemplary embodiments, wherein a control valve is associated with the extraction line and a level control device is associated with the pump reservoir, which is configured to control a level in the pump reservoir by actuating the control valve.
[0049] 9. Exemplary embodiment: The system according to one of the preceding exemplary embodiments, wherein a filter device with a filter element contained therein is connected upstream of the pump container on the inlet side, and wherein the filter device is arranged outside the pump container and / or the ship's tank in such a way that the filter element can be replaced without opening the pump container and / or the ship's tank.
[0050] 10. Exemplary embodiment: The system according to one of the preceding exemplary embodiments, wherein the ship tank has a sump, which is formed in particular in a bottom or on the underside of the ship tank, and wherein the extraction line is led into the sump.
[0051] 11. Exemplary embodiment: Ship with a ship tank, a ship propulsion system and a system for extracting cryogenic and deep-cooled liquefied gas from the ship tank, wherein the system is designed according to one of the preceding exemplary embodiments.
[0052] 12. Exemplary embodiment: Use of a system according to an exemplary embodiment 1-10 for a ship, in particular for a ship powered by one of the following liquefied gases:
[0053] Liquefied Natural Gas (LNG),
[0054] Ethan,
[0055] Liquefied Petroleum Gas (LPG),
[0056] Ammonia.
[0057] 13. Exemplary embodiment: Method for extracting cryogenic and cryogenic liquefied gas from a ship's tank for a gas consumer, in particular as fuel for a ship's propulsion system, comprising the steps:
[0058] Providing a pump container which is connected to a ship's tank via a suction line,
[0059] Controlling the pressure in the pump container such that it is lower than the internal pressure of the ship's tank, in order to transfer the liquefied gas from the ship's tank to the pump container based on the pressure difference. 14. Embodiment: The method according to embodiment 13, wherein the ship's tank is fluidly connected to a compressor system via a control valve, and wherein the method comprises the step:
[0060] Control, in particular reducing the pressure inside the ship's tank by opening the control valve to the compressor system, especially when a maximum differential pressure between pump tank and ship's tank or the maximum operating pressure of the ship's tank is exceeded.
[0061] 15. Embodiment: Method according to embodiment 13 or 14, wherein the ship's tank is fluidly connected to a liquefied gas heating system via a control valve, and wherein the method comprises the step:
[0062] Control, in particular increasing the pressure inside the ship's tank by opening the control valve to the liquefied gas heating system, especially when a minimum differential pressure between the pump tank and the ship's tank is not reached.
[0063] 16. Exemplary embodiment: Method according to exemplary embodiment 15, wherein the minimum differential pressure, in particular depending on the design and arrangement of the ship tank and fuel gas preparation room, is preferably 0.5 bar and / or the maximum differential pressure is, for example, 1 bar to 1.5 bar.
[0064] Further features and advantages of the invention will become apparent from the attached claims and the following description, in which exemplary embodiments are explained in detail with reference to schematic drawings.
[0065] Specifically, we show:
[0066] Fig. 1 shows a ship with a system according to the invention in a first embodiment for extracting cryogenic and deep-cold liquefied gas for a gas consumer, in particular a ship's propulsion system, from the ship's tank in a schematic representation;
[0067] Fig. 2 shows a ship with a system according to a second embodiment of the invention for extracting cryogenic and deep-cold liquefied gas for a gas consumer, in particular a ship's propulsion system, from the ship's tank in a schematic representation;
[0068] Fig. 3 shows a block diagram of the method according to the invention. Figs. 1 and 2 show a schematically indicated ship 100. The ship 100 has a ship tank 4. The ship 100 also has a gas consumer 6, which is exemplary configured as a ship propulsion system 6, and a system 2 for extracting cryogenic and extremely cold liquefied gas F as fuel for the ship propulsion system 6 from the ship tank 4. A tank connection chamber 50 is arranged above the ship tank 4. This, in turn, is connected via lines not specified in detail to a fuel gas treatment chamber 48.
[0069] System 2 has a withdrawal line 8 for extracting liquefied gas F from the ship's tank 4. The withdrawal line 8 extends into the ship's tank 4. As shown in Fig. 1 and Fig. 2, the withdrawal line 8 extends to a lower region of the ship's tank 4.
[0070] In the embodiment shown in Fig. 1, a collection tank 9, designed as a pump tank 10, is fluid-conductingly connected to the extraction line 8. In this embodiment, the pump tank 10 is located in the fuel gas conditioning chamber 48. Thus, the pump tank 10 is located outside the ship's tank 4 and is configured to extract the liquefied gas F from the ship's tank 4 via the extraction line 8. The pump tank 10 has a differential pressure control device 12. The differential pressure control device 12 is configured to control the internal pressure Pp in the pump tank 10 such that it is lower than the internal pressure PT of the ship's tank 4. In this way, the liquefied gas F can be transferred from the ship's tank 4 to the pump tank 10 based on the pressure difference, without the need to install pumps inside the ship's tank 4.This ensures that, in the event of maintenance work or a necessary replacement, very easy access to a pump 14 located inside the pump tank 10 is guaranteed.
[0071] The pump housing 10 includes a pump 14. The pump 14 is preferably designed as a fuel gas pump 14. The pump 14 is configured to pump the liquefied gas F from the pump housing 10 to the gas consumer 6 or ship propulsion system 6. The pump housing has a housing opening 17, in particular a manhole. After opening the housing opening 17, the pump 14 located inside the pump housing 10 becomes accessible and can be serviced or replaced. A first pressure sensor 18 for measuring the internal pressure Pp in the pump housing is associated with the pump housing 10. A second pressure sensor 20 for measuring the internal pressure PT in the ship tank 4 is associated with the ship tank 4. The pressure sensors 18 and 20 are connected to the differential pressure control device 12 via signal transmission.
[0072] In the embodiment shown in Fig. 2, a collection tank 9 is fluidly connected to the extraction line 8. The collection tank 9 is also fluidly connected to a separate pump tank 10 via a connecting line 11. In this embodiment, the collection tank 9 and the pump tank 10 are located in the fuel gas conditioning chamber 48. Thus, the collection tank 9 and the pump tank 10 are located outside the ship's tank 4 and are configured to extract the liquefied gas F from the ship's tank 4 via the extraction line 8. The collection tank 9 has a differential pressure control device 12. The differential pressure control device 12 is configured to control the internal pressure Pp in the collection tank 9 such that it is lower than the internal pressure PT of the ship's tank 4.In this way, the liquefied gas F can be transferred from the ship's tank 4 to the collection tank 9 based on the pressure difference, without the need to install pumps inside the ship's tank 4. This ensures very easy access to a pump 14 located inside the pump housing 10 in the event of maintenance work or a necessary replacement.
[0073] The pump housing 10 includes a pump 14. The pump 14 is preferably designed as a fuel gas pump 14. The pump 14 is configured to pump the liquefied gas F from the pump housing 10 to the gas consumer 6 or ship propulsion system 6. A first pressure sensor 18 for measuring the internal pressure Pp in the collection tank 9 is assigned to the collection tank 9. A second pressure sensor 20 for measuring the internal pressure PT in the ship tank 4 is assigned to the ship tank 4. The pressure sensors 18 and 20 are connected to the differential pressure control device 12 via signal transmission.
[0074] The collection tank 9 of the embodiments shown in Figs. 1 and 2 is further connected via a control valve 22 to a compressor system 24 of the ship 100. The differential pressure control device 12 is configured to selectively open the first control valve 22 to the compressor system 24 in order to regulate the pressure Pp inside the collection tank 9 to a lower pressure. In the embodiments shown in Figs. 1 and 2, the compressor system 24 is a BOG compressor system 26 of the ship 100. The ship 100 also has a liquefied gas heating system 30. The liquefied gas heating system 30 is connected via a control valve 44 to the ship's tank 4.The differential pressure control device 12 is configured to selectively open the control valve 44 and supply vaporized gas from the liquefied gas heating system 30 to the ship's tank 4 when a minimum differential pressure APmin between the collection tank 9 and the ship's tank 4 is undershot. By supplying the vaporized gas from the liquefied gas heating system 30 to the ship's tank 4, the pressure in the ship's tank 4 is increased, and thus also the differential pressure between the collection tank 9 and the ship's tank 4.
[0075] The ship tank 4 is also fluidly connected to the compressor system 24 via a control valve 32. The differential pressure control device 12 is configured to open the control valve 32 when a maximum differential pressure APmax between the collection tank 9 and the ship tank 4 is exceeded, or when the maximum operating pressure of the ship tank is exceeded, in order to supply vaporized gas from the ship tank 4 to the compressor system 24. By supplying the vaporized gas from the ship tank 4 to the compressor system 24, the pressure in the ship tank 4 can be reduced, and thus the overall differential pressure between the collection tank 9 and the ship tank 4 can be regulated.
[0076] A control valve 33 is assigned to the extraction line 8. A level control device 34 is assigned to the collection tank 9. The level control device 34 is configured to control the fill level in the collection tank 9 by actuating the control valve 33. In this way, the fill level of the collection tank 9 can be monitored and controlled.
[0077] A filter assembly 36 with a filter element 38 is installed upstream of the inlet side of the pump housing 10. The filter element 38 serves to filter the liquefied gas F. The filter assembly 36 is located outside the pump housing 10 and also outside the ship tank 4 and the tank connection compartment 50, such that the filter element 38 can be replaced without opening the pump housing 10, the ship tank 4, or the tank connection compartment 50. This simplifies the maintenance of a pump 14 located in the pump housing 10.
[0078] The ship tank 4 also has a sump 40, which is formed in particular in a base or on the underside 42 of the ship tank 4. The extraction line 8 extends into the sump 40, so that the ship tank 4 can be almost completely emptied. The supply of vaporized liquefied gas from the liquefied gas heating system 30 via the control valve 44 into the ship tank 4 is effected by the supply line 46. The tank connection room 50 is connected to bunkering stations 52 via a liquid line 54 and a vapor return line 56.
[0079] Fig. 3 shows a block diagram of a method 200 for extracting cryogenic and extremely cold liquefied gas F from a ship tank 4. The method 200 comprises the following steps: providing 202 a collection tank 9, which is connected to a ship tank 4 via an extraction line 8; controlling 204 a pressure Pp in the collection tank 9 such that it is lower than an internal pressure PT of the ship tank 4, in order to transfer the liquefied gas F from the ship tank 4 to the collection tank 9 based on the pressure difference.
[0080] The collection tank 9 can be a pump tank 10 and have a pump 14 which is designed to pump the liquefied gas F from the pump tank 10 to the ship's propulsion 6, and wherein the pump tank 10 has a tank opening 17, in particular a manhole, for replacing the pump 14.
[0081] Method 200 further comprises the step: Control 206, in particular reducing the pressure PT inside the ship's tank 4 by opening the control valve 32 to the compressor system 24, especially when a maximum differential pressure APmax between the collection tank 9 and the ship's tank 4 or the maximum operating pressure of the ship's tank is exceeded. Method 200 further comprises the step: Control 208, in particular increasing the pressure PT inside the ship's tank 4 by opening the control valve 44 to the liquefied gas heating system 30, especially when a minimum differential pressure APmin between the collection tank 9 and the ship's tank 4 is not reached. The minimum differential pressure APmin is, for example, 0.5 bar, depending on the design and arrangement of the ship's tank and the fuel gas processing chamber, and the maximum differential pressure APmax is, for example, 1 to 1.5 bar.
[0082] Furthermore, the process 200 can include the step: providing 210 a pump tank 10 with a pump 14, which is configured to pump the liquefied gas F from the pump tank 10 to the ship's propulsion 6. Reference list
[0083] 2. Extraction system
[0084] 4 ship tanks
[0085] 6 Gas consumers, especially ship propulsion
[0086] 8 Extraction line
[0087] 9 collection containers
[0088] 10 pump containers
[0089] 11 Connecting line
[0090] 12 Differential pressure control device
[0091] 14 Pump
[0092] 17 Container opening
[0093] 18 first pressure sensor of the collection container
[0094] 20 Second pressure sensor of the ship's tank
[0095] 22 Control valve
[0096] 24 compressor system
[0097] 26 BOG compressor system
[0098] 27 Vapor Return compressor system
[0099] 28 Reliquefaction system
[0100] 30 Liquid gas heating system
[0101] 32 Control valve
[0102] 33 Control valve
[0103] 34 Level control device
[0104] 36 Filter system
[0105] 38 filter elements
[0106] 40 swamp
[0107] 42 Tank bottom
[0108] 44 Control valve
[0109] 46 Supply line for vaporized gas to the ship's tank
[0110] 48 Fuel gas treatment room
[0111] 50 Tank connection room
[0112] 52 Bunker Station
[0113] 54 Liquid line
[0114] 56 Steam recirculation
[0115] 100 ships
[0116] 200 extraction procedures
[0117] 202 Providing a collection container 204 Controlling pressure in the collection container
[0118] 206 Reducing the pressure inside the ship's tank
[0119] 208 Increasing the pressure inside the ship's tank
[0120] 210 Provision of a pump container F Liquefied gas
[0121] PP pressure inside the collection container
[0122] PT pressure inside the ship's tank
[0123] APmax maximum differential pressure between collection tank and ship tank
[0124] APmin minimum differential pressure between collection tank and ship tank
Claims
Claims 1. System (2) for extracting cryogenic and cryogenic liquefied gas (F) from at least one ship tank (4) for a gas consumer (6), in particular as fuel for a ship propulsion system (6), or a cargo system, comprising: an extraction line (8) for extracting liquefied gas (F) from the ship tank (4), wherein the extraction line (8) extends into the ship tank (4), a collection tank (9) connected to the extraction line (8), characterized in that the collection tank (9) is arranged outside the ship tank (4) and is configured to extract the liquefied gas (F) from the ship tank (4) via the extraction line (8), wherein the collection tank (9) has a differential pressure control device (12) which is configured to control an internal pressure (Pp) in the collection tank (9) such that it is lower than the internal pressure (PT) of the ship tank (4),to transfer the liquefied gas (F) from the ship's tank (4) to the collection tank (9) based on the pressure difference.
2. The system (2) according to claim 1, wherein the collection container (9) is designed as a pump container (10) and has a pump (14) which is configured to pump the liquefied gas (F) from the pump container (10) to the ship's propulsion (6) or a component of a cargo system, in particular wherein the pump container (10) has a container opening (17), preferably a manhole, for replacing the pump (14).
3. The system (2) according to claim 1, wherein the system additionally comprises a pump container (10) with a pump (14) which is configured to pump the liquefied gas (F) from the pump container (10) to the ship's propulsion (6) or a component of a cargo system, and wherein the pump container (10) is fluidly connected to the collection container (9) via a connecting line (11).
4. The system (2) according to one of the preceding claims, wherein a first pressure sensor (18) for measuring the internal pressure (Pp) in the collection container (9) is assigned to the collection container (9) and a second pressure sensor (20) for measuring the internal pressure (PT) in the ship tank (4) is assigned to the ship tank (4), wherein the pressure sensors (18, 20) are connected to the differential pressure control device (12) via signal transmission.
5. The system (2) according to one of the preceding claims, wherein the collection tank (9) is fluidly connected to a compressor system (24) via a control valve (22), and wherein the differential pressure control device (12) is configured to selectively open the first control valve (22) to the compressor system (24) in order to regulate the pressure (Pp) inside the collection tank (9) to a lower pressure than in the ship's tank (4).
6. The system (2) according to claim 5, wherein the compressor system (24) is a BOG compressor system (26), a vapor return compressor system (27), a reliquefaction system (28) of a ship (100).
7. The system (2) according to one of the preceding claims, wherein a liquefied gas heating system (30) is fluidly connected to the ship's tank (4) via a control valve (44), and wherein the differential pressure control device (12) is configured to selectively open the control valve (44) and supply vaporized gas from the liquefied gas heating system (30) to the ship's tank (4) when a minimum differential pressure (APmin) between the collection tank (9) and the ship's tank (4) is undershot.
8. The system (2) according to any one of claims 5 to 7, wherein the ship tank (4) is fluidly connected to the compressor system (24) via a control valve (32), and wherein the differential pressure control device (12) is configured to open the control valve (32) when a maximum differential pressure (AP-max) between the collection tank (9) and the ship tank (4) is exceeded or when the maximum operating pressure in the ship tank (4) is exceeded, in order to supply vaporized gas from the ship tank (4) to the compressor system (24).
9. The system (2) according to one of the preceding claims, wherein a control valve (33) is assigned to the extraction line (8) and a level control device (34) is assigned to the collection container (9), which is configured to control a level in the collection container (9) by actuating the control valve (33).
10. The system (2) according to one of the preceding claims, wherein a filter device (36) with a filter element (38) received therein is connected upstream of the pump container (10) on the inlet side, and wherein the filter device (36) is arranged outside the pump container (10) and / or the ship tank (4) in such a way that the filter element (38) is replaceable without opening the pump container (10) and / or the ship tank (4).
11. The system (2) according to one of the preceding claims, wherein the ship tank (4) has a sump (40) which is formed in particular in a bottom or on the underside (42) of the ship tank (4), and wherein the extraction line (8) extends into the sump (40).
12. Ship (100) comprising a ship tank (4), a ship propulsion system (6) and a system (2) for extracting cryogenic and supercooled liquefied gas (F) from the ship tank (4), wherein the system (2) is configured according to one of the preceding claims.
13. Use of a system (2) according to any one of claims 1-11 for a ship (100), in particular for a ship or cargo system powered by one of the following liquefied gases (F): Liquefied Natural Gas (LNG), Ethan, Liquefied Petroleum Gas (LPG), Liquefied carbon dioxide (LCO2) (limited to cargo system) Ammonia.
14. Method (200) for extracting cryogenic and supercooled liquefied gas (F) from a ship tank (4) for a gas consumer (6), in particular as fuel for a ship propulsion system (6), or a cargo system, comprising the steps: Providing (202) a collection container (9) which is connected to a ship tank (4) via a withdrawal line (8), Controls (204) of a pressure (P p) in the collection container (9) such that it is lower than the internal pressure (PT) of the ship's tank (4) in order to transfer the liquefied gas (F) from the ship's tank (4) to the collection container (9) based on the pressure difference 15. Method (200) according to claim 14, wherein the collection container (9) is a pump container (10) and has a pump (14) which is configured to pump the liquefied gas (F) from the pump container (10) to the ship's propulsion (6) or a component of a cargo system, and wherein the pump container (10) has a container opening (17), in particular a manhole, for replacing the pump (14).
16. Method (200) according to claim 14, wherein the method (200) additionally comprises the following step: Providing (210) a pump container (10) with a pump (14) which is configured to pump the liquefied gas (F) from the pump container (10) to the ship's propulsion (6) or a component of a cargo system.
17. Method (200) according to one of the preceding claims, wherein the ship tank (4) is fluidly connected to a compressor system (24) via a control valve (32), and wherein the method (200) comprises the step: Control (206), in particular reducing the pressure (PT) inside the ship's tank (4) by opening the control valve (32) to the compressor system (24), especially when a maximum differential pressure (APmax) between the collection tank (9) and the ship's tank (4) or the maximum operating pressure of the ship's tank (4) is exceeded.
18. Method (200) according to one of the preceding claims, wherein the ship tank (4) is fluidly connected to a liquefied gas heating system (30) via a control valve (44), and wherein the method (200) comprises the step: Control (208), in particular increasing the pressure (PT) inside the ship's tank (4) by opening the control valve (44) to the liquefied gas heating system (30), especially when a minimum differential pressure (APmin) between the collection tank (9) and the ship's tank (4) is undershot.
19. Method (200) according to one of the preceding claims, wherein the minimum differential pressure (APmin) is 0.5 bar, in particular depending on the design and arrangement of the ship tank and fuel gas preparation room, and / or the maximum differential pressure (APmax) is e.g. 1 bar to 1.5 bar.