Gas fuel supply system

Abstract

To provide a gas fuel supply system with replaceable cartridges and low cost. [Solution] A gas fuel supply system 2 for a ship according to one embodiment includes a plurality of cartridges 3 that are detachable from the ship's hull and each include a tank 32 for storing liquefied gas, and a gas fuel supply line 4 that guides the vaporized gas of the liquefied gas discharged from the cartridges 3 to a gas consumer as gas fuel. The gas fuel supply line 4 includes a plurality of branch lines 44 connected to the cartridges 3 and a main flow line 41 to which the branch lines 44 are connected. A vaporizer 43 is provided in the main flow line 41.

Description

Technical Field

[0001] The present disclosure relates to a gas fuel supply system mounted on a ship.

Background Art

[0002] Some ships are equipped with gas consumers that consume gas fuel to generate power or electricity. For example, the gas consumers include reciprocating engines, gas turbine engines, boilers, fuel cells, and the like. Such ships are also equipped with a gas fuel supply system that supplies vaporized gas of liquefied gas as gas fuel to the gas consumers.

[0003] For example, Patent Document 1 discloses a gas fuel supply system including a plurality of cartridges called fuel containers that are detachable from the hull. Each cartridge includes a tank for storing liquefied gas and a vaporizer for vaporizing the liquefied gas derived from the tank. Further, FIG. 3 of Patent Document 1 describes a gas fuel supply line that guides vaporized gas from two cartridges as gas fuel to a reciprocating engine.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] If a cartridge including a tank is detachable from the hull like the gas fuel supply system of Patent Document 1, the cartridge with an empty tank can be replaced with a cartridge with a full tank without performing a bunkering operation of refilling liquefied gas into the tank on the ship.

[0006] However, in the gas fuel supply system of Patent Document 1, since each cartridge includes a vaporizer, the cost is high. Therefore, the present disclosure aims to provide a gas fuel supply system that allows for cartridge replacement and is low-cost. [Means for solving the problem]

[0007] This disclosure provides a gas fuel supply system for installation on a ship, comprising: a plurality of cartridges, each including a tank for storing liquefied gas and detachable from the hull of the ship; a gas fuel supply line for guiding vaporized gas from the plurality of cartridges to a gas consumer as gas fuel, the gas fuel supply line including a plurality of branch lines connected to the plurality of cartridges and a main flow line to which the plurality of branch lines are connected; and a vaporizer provided in the main flow line. [Effects of the Invention]

[0008] According to this disclosure, a gas fuel supply system is provided that allows for cartridge replacement and is low-cost. [Brief explanation of the drawing]

[0009] [Figure 1] This is a schematic diagram of a ship equipped with a gas fuel supply system according to one embodiment. [Figure 2] This is a schematic diagram of one cartridge included in the aforementioned gas fuel supply system. [Figure 3] This is a schematic diagram of the gas fuel supply system. [Figure 4] This diagram shows the fluid flow in the first mode, indicated by a thick line. [Figure 5] This diagram shows the fluid flow in the second mode, indicated by a thick line. [Figure 6] This diagram shows the fluid flow in the third mode, indicated by a thick line. [Modes for carrying out the invention]

[0010] Figure 1 shows a gas fuel supply system 2 according to one embodiment. In this embodiment, the gas fuel supply system 2 is installed on the ship 1 together with a first gas consumer 12 and a second gas consumer 13.

[0011] The gas fuel supply system 2 supplies the vaporized gas of the liquefied gas discharged from the tank 32 (described later) as gas fuel to the first gas consumer 12, and also supplies the boil-off gas (BOG) generated in the tank 32 to the second gas consumer 13. Here, "vaporized gas" is a concept that includes not only the gas phase but also the supercritical state. The gas fuel supply system 2 may also supply BOG as gas fuel to the first gas consumer 12.

[0012] The first gas consumer 12 consumes gaseous fuel to generate propulsion power or electricity for propulsion or onboard use. For example, the first gas consumer 12 may be a reciprocating engine, a gas turbine engine, a boiler, a fuel cell, etc.

[0013] The second gas consumer 13 consumes excess BOG to regulate the pressure in the tank 32. For example, the second gas consumer 13 is a GCU (Gas Combustion Unit). The second gas consumer 13 may also be a reciprocating engine, boiler, or fuel cell used for generating electricity or as a heat source for the ship. In Figure 1, the second gas consumer 13 is located on the open deck of the hull 11, but part or all of the second gas consumer 13 may be located below the open deck.

[0014] In this embodiment, the liquefied gas is liquefied hydrogen. However, the liquefied gas is not limited to this and may be LNG (Liquefied Natural Gas), LPG (Liquefied Petroleum Gas), etc.

[0015] The gas fuel supply system 2 includes a plurality of cartridges 3 that are detachable from the hull 11 of the ship 1, and a fuel hub 21 interposed between the cartridges 3, the first gas consumer 12, and the second gas consumer 13. In FIG. 1, the fuel hub 21 is disposed on the open deck of the hull 11, but a part of the fuel hub 21 may be disposed on the open deck and the remainder may be disposed below the open deck.

[0016] In the present embodiment, three cartridges 3 are stacked in a row on the open deck of the hull 11. That is, the upper cartridge 3 is detachable from the hull 11 via the lower cartridge 3. However, the number of cartridges 3 may be two, or may be four or more. Also, the cartridges 3 may be stacked in multiple rows, or two or more cartridges 3 may be placed on the open deck side by side.

[0017] As shown in FIG. 2, each cartridge 3 includes a tank 32 for storing liquefied gas and a frame 31 for supporting the tank 32. For example, the frame 31 includes a plurality of beams and columns along each side of a rectangular parallelepiped extending in the lateral direction.

[0018] BOG is generated by evaporation of the liquefied gas in the tank 32. That is, in the tank 32, a liquid layer is formed by the liquefied gas and a gas layer is formed by the BOG. For example, the tank 32 is a double-walled tank with a vacuum between the inner tank and the outer tank. However, the tank 32 may be a single-walled tank covered with a heat insulating material. Also, in the present embodiment, the tank 32 is horizontally cylindrical, but the tank 32 may be vertically cylindrical, or may be spherical or substantially rectangular parallelepiped-shaped.

[0019] Each cartridge 3 also includes a liquefied gas outlet pipe 33 extending from the liquid layer of the tank 32 and a BOG outlet pipe 35 extending from the gas layer of the tank 32. Joints 3a and 3b are provided at the tips of the liquefied gas outlet pipe 33 and the BOG outlet pipe 35 respectively, and valves 34 and 36 are provided in the middle of the liquefied gas outlet pipe 33 and the BOG outlet pipe 35 respectively. Each of the joints 3a and 3b may be a half of a flange joint or a half of a bayonet joint (male or female).

[0020] Furthermore, each cartridge 3 includes a pressure gauge (PT: Pressure Transmitter) 81, a thermometer (TT: Temperature Transmitter) 82, and a liquid level gauge (LT: Level Transmitter) 83, and also includes a control panel 37 electrically connected to the pressure gauge 81, the thermometer 82, the liquid level gauge 83, and the above-mentioned valves 34 and 36. The control panel 37 is also electrically connected to a connector 3c for connection to a cable 73 described later.

[0021] The pressure gauge 81 detects the gas layer pressure of the tank 32. The thermometer 82 detects the gas layer temperature or the liquid layer temperature of the tank 32. The liquid level gauge 83 detects the liquid level height in the tank 32. The control panel 37 may have a function of controlling the valves 34 and 36 based on the detection results of the pressure gauge 81, the thermometer 82, and the liquid level gauge 83. Alternatively, the control panel 37 may only have a function of a junction box that relays the detection results of the pressure gauge 81, the thermometer 82, and the liquid level gauge 83, as well as the opening degree command to the valves 34 and 36.

[0022] As shown in FIG. 3, the fuel hub 21 includes a gas fuel supply line 4 that guides the vaporized gas of the liquefied gas derived from all the cartridges 3 to the first gas consumer 12 as gas fuel, and a BOG supply line 5 that guides the BOG from all the cartridges 3 to the second gas consumer 13. In FIG. 3, one of the cartridges 3 is omitted for simplicity of the drawing.

[0023] The gas fuel supply line 4 includes a plurality of first branch lines 44, each connected to a cartridge 3, and a first main flow path 41 to which the first branch lines 44 are connected. The upstream end of each first branch line 44, which is a liquefied gas pipeline, is connected to the fitting 3a of the corresponding cartridge 3. Each first branch line 44 is also provided with a check valve 45 to prevent backflow of liquefied gas.

[0024] A valve 42 is provided in the first main flow path 41, and a pump 43 is provided downstream of the valve 42. As described above, in this embodiment, the liquefied gas is liquefied hydrogen, so the pump 43 increases the pressure of the liquefied hydrogen to a pressure higher than the pressure required by the first gas consumer 12, bringing it to a supercritical state. As described above, the concept of "vaporized gas" includes the supercritical state, so "vaporization" includes bringing it to a supercritical state. Therefore, the pump 43 is also a vaporizer that vaporizes the liquefied gas.

[0025] However, if the liquefied gas is LNG or the like, the first main flow path 41 may be equipped with a compressor instead of the pump 43, and a vaporizer, which is a heat exchanger, may be provided upstream of the compressor. Alternatively, the pump 43 may discharge the liquefied gas, and a vaporizer, which is a heat exchanger, may be provided downstream of the pump 43. Furthermore, regardless of whether the liquefied gas is liquefied hydrogen or LNG or the like, the first main flow path 41 may be equipped with a heater that heats the gas fuel, which is a vaporized gas, to the temperature required by the first gas consumer 12.

[0026] The BOG supply line 5 includes a number of second branch lines 54, each connected to a cartridge 3, and a second main flow path 51 to which the second branch lines 54 are connected. The upstream end of each second branch line 54, which is a BOG pipe, is connected to the fitting 3b of the corresponding cartridge 3.

[0027] Valves 52 and 53 are provided in the second main passage 51. Furthermore, a pressure gauge 84 is provided downstream of valve 53 in the second main passage 51. The pressure gauge 84 detects the pressure of the BOG supplied to the second gas consumer 13. The second main passage 51 may be provided with a compressor for sending out the BOG, or with a heater for heating the BOG to a temperature suitable for supplying it to the second gas consumer 13.

[0028] Furthermore, in this embodiment, the relay line 6 branches off from the first main passage 41 of the gas fuel supply line 4 between the valve 42 and the pump 43, and connects to the second main passage 51 of the BOG supply line 5 between the valves 52 and 53. The relay line 6 is equipped with a vaporizer 62, and valves 61 and 63 are provided upstream (between the vaporizer 62 and the first main passage 41) and downstream (between the vaporizer 62 and the second main passage 51) of the vaporizer 62, respectively.

[0029] Valves 42, 52, 53, 61, 63 and pressure gauge 84 located in the gas fuel supply line 4, BOG supply line 5, and relay line 6 are electrically connected to the control device 7. The control device 7 is also electrically connected to the connectors 3c of all cartridges 3 via cable 73.

[0030] The control device 7 includes a processing circuit 71 that controls valves 42, 52, 53, 61, and 63 provided in the gas fuel supply line 4, the BOG supply line 5, and the relay line 6, as well as controlling valves 34 and 36 of each cartridge 3 via the control panel 37. The control device 7 also includes a user interface 72 having a display screen that functions as an input and display. The user interface 72 is, for example, a touchscreen. However, instead of including the user interface 72 in the control device 7, an input and a display may be electrically connected to the control device 7.

[0031] With respect to the control device 7, the functions of the elements disclosed herein can be performed using circuits or processing circuits, including general-purpose processors, dedicated processors, integrated circuits, ASICs (Application Specific Integrated Circuits), conventional circuits, and / or combinations thereof, configured or programmed to perform the disclosed functions. A processor is considered a processing circuit or circuit because it includes transistors and other circuits. In this disclosure, a circuit, unit, or means is hardware that performs the enumerated functions, or hardware programmed to perform the enumerated functions. The hardware may be hardware disclosed herein, or other known hardware that is programmed or configured to perform the enumerated functions. If the hardware is a processor, which is considered a type of circuit, then the circuit, means, or unit is a combination of hardware and software, and the software is used to configure the hardware and / or the processor.

[0032] The processing circuit 71 controls valves 34, 36, 42, 52, 53, 61, and 63 based on the pressure detected by pressure gauges 81 and 84. Specifically, when the processing circuit 71 is discharging liquefied gas from two of the cartridges 3, if the differential pressure ΔP of the gas layer pressure in the tanks 32 of both cartridges 3 is less than a predetermined value α, it keeps the valves 36 of both cartridges 3 closed and opens the valves 34 of both cartridges 3 and the valve 42 provided in the gas fuel supply line 4.

[0033] If the higher of the two gas layer pressures in the tanks 32 of the cartridges 3 is denoted as Ph and the lower as Pl, then ΔP = Ph - Pl. The predetermined value α compared with ΔP is determined by considering the difference in height (so-called head difference) between the liquefied gas outlet pipes 33 of the two cartridges 3 and the pressure loss in the first branch lines 44 corresponding to both cartridges 3 in the gas fuel supply line 4. In other words, if there is a pressure difference at the position of the check valve 45 in the first branch lines 44 corresponding to both cartridges 3, the supply of liquefied gas from one of the cartridges 3 will be stopped, so the predetermined value α is determined so that the supply of liquefied gas from both cartridges 3 is possible.

[0034] On the other hand, if the differential pressure ΔP of the gas layer pressure in the tanks 32 of both cartridges 3 is greater than or equal to a predetermined value α, the processing circuit 71 executes one of the following modes: the first mode shown in Figure 4, the second mode shown in Figure 5, or the third mode shown in Figure 6.

[0035] The first mode is executed when the lower gas layer pressure Pl is lower than the pressure P0 detected by the pressure gauge 84. In Figure 4, the gas layer pressure in the tank 32 of the lower cartridge 3 is lower than the gas layer pressure in the tank 32 of the upper cartridge 3.

[0036] In the first mode, the processing circuit 71 controls valves 34, 36, 42, 52, 53, 61, and 63 so that the vaporized gas vaporized in the vaporizer 62 is supplied to the cartridge 3 with the lower gas pressure in the tank 32. More specifically, the processing circuit 71 keeps valve 36 closed and opens valve 34 in the cartridge 3 with the higher gas pressure in the tank 32, and opens both valves 34 and 36 in the cartridge 3 with the lower gas pressure in the tank 32. The processing circuit 71 also closes valve 53 and opens valves 42, 61, 63, and 52. Then, when the gas pressures in the tanks 32 of both cartridges 3 become approximately equal, the processing circuit 71 closes valves 61, 63, and 52, as well as valve 36 in the cartridge 3 with the lower gas pressure in the tank 32.

[0037] The second mode is executed when the higher gas layer pressure Ph is higher than the pressure P0 detected by the pressure gauge 84. In Figure 5, the gas layer pressure in the tank 32 of the upper cartridge 3 is higher than the gas layer pressure in the tank 32 of the lower cartridge 3.

[0038] In the second mode, the processing circuit 71 controls valves 34, 36, 42, 52, 53, 61, and 63 so that BOG is derived only from the cartridge 3 with the higher gas pressure in the tank 32. More specifically, the processing circuit 71 keeps valve 36 closed and opens valve 34 for the cartridge 3 with the lower gas pressure in the tank 32, and opens both valves 34 and 36 for the cartridge 3 with the higher gas pressure in the tank 32. The processing circuit 71 also closes valves 61 and 63 and opens valves 42, 52, and 53. Then, when the gas pressures in the tanks 32 of both cartridges 3 become approximately equal, the processing circuit 71 closes valves 52 and 53 and valve 36 for the cartridge 3 with the higher gas pressure in the tank 32.

[0039] Depending on the installation location of cartridge 3, the air pressure balance between cartridges 3 may change due to external heat intrusion such as direct sunlight. The third mode is a mode that is executed to adjust the air pressure balance between the two cartridges 3 in such cases.

[0040] In the third mode, the processing circuit 71 controls valves 34, 36, 42, 52, 53, 61, and 63 so that the gas layers in the tanks 32 of both cartridges 3 are in communication with each other. More specifically, as shown in Figure 6, the processing circuit 71 opens valves 34 and 36 of both cartridges 3. The processing circuit 71 also closes valves 52, 53, 61, and 63 and opens valve 42. Then, when the gas layer pressures in the tanks 32 of both cartridges 3 become approximately equal, the processing circuit 71 closes valve 36 of both cartridges 3.

[0041] As described above, in the gas fuel supply system 2 of this embodiment, since the cartridge 3 is detachable from the hull 11, an empty cartridge 3 can be replaced with a full cartridge 3. Moreover, since the pump 43 that functions as a vaporizer is provided in the gas fuel supply line 4 rather than in each cartridge 3, the cost is lower compared to the case where each cartridge 3 is equipped with a vaporizer.

[0042] Furthermore, in the first mode shown in Figure 4, the tank 32 with the lower gas layer pressure can be pressurized, making it possible to make the gas layer pressures of the tanks 32 of both cartridges 3 approximately the same. This allows for stabilization of the pressure of the gas fuel supplied to the first gas consumer 12.

[0043] Furthermore, in the second mode shown in Figure 5, the tank 32 with the higher gas layer pressure can be depressurized, making it possible to make the gas layer pressures of the tanks 32 of both cartridges 3 approximately the same. This allows the pressure of the gas fuel supplied to the first gas consumer 12 to be stabilized.

[0044] Furthermore, in the third mode shown in Figure 6, the tanks 32 of both cartridges 3 can be pressurized. This stabilizes the pressure of the gas fuel supplied to the first gas consumer 12.

[0045] <Variation> This disclosure is not limited to the embodiments described above, and various modifications are possible without departing from the gist of this disclosure.

[0046] For example, the vaporizer 62 may be used as a pressurizing device that returns the vaporized gas to the tank 32 in order to discharge the liquefied gas from the tank 32 and pressurizes the inside of the tank 32.

[0047] Alternatively, a vent mast that releases BOG into the atmosphere may be used instead of the second gas consumer 13. However, if the second gas consumer 13 is used as in the above embodiment, the boil-off gas generated in the tank 32 of each cartridge 3 can be effectively utilized by the second gas consumer 13.

[0048] <Summary> In a first aspect, the present disclosure provides a gas fuel supply system for installation on a ship, comprising: a plurality of cartridges, each including a tank for storing liquefied gas and detachable from the hull of the ship; a gas fuel supply line for guiding vaporized gas from the plurality of cartridges to a gas consumer as gas fuel, the gas fuel supply line including a plurality of branch lines connected to the plurality of cartridges and a main flow line to which the plurality of branch lines are connected; and a vaporizer provided in the main flow line.

[0049] With the above configuration, since the cartridges are detachable from the hull, an empty cartridge can be replaced with a full one. Moreover, since vaporizers are installed in the gas fuel supply line rather than in each cartridge, the cost is lower compared to a system where each cartridge has its own vaporizer.

[0050] In a second embodiment, in the first embodiment, the branching path is a first branching path, the main flow path is a first main flow path, and the gas consumption device is a first gas consumption device, and the gas fuel supply system is a boil-off gas supply line that guides the boil-off gas generated in the tank from the plurality of cartridges to a second gas consumption device, and may further include a boil-off gas supply line that includes a plurality of second branching paths connected to the plurality of cartridges, and a second main flow path to which the plurality of second branching paths are connected. With this configuration, the boil-off gas generated in the tank of each cartridge can be effectively utilized by the second gas consumption device.

[0051] In a third embodiment, in the second embodiment, the vaporizer is a first vaporizer, and the gas fuel supply system further comprises a relay line branching from the first main flow path and connected to the second main flow path, a second vaporizer provided on the relay line, a plurality of valves provided on the gas fuel supply line, the boil-off gas supply line, and the relay line, and a processing circuit for controlling the plurality of valves, wherein when the liquefied gas is discharged from two of the plurality of cartridges, if the differential pressure of the gas bed pressure in the tanks of both cartridges is greater than or equal to a predetermined value, the plurality of valves may be controlled so that the vaporized gas vaporized by the second vaporizer is supplied to the cartridge with the lower gas bed pressure in its tank. With this configuration, the tank with the lower gas bed pressure can be pressurized, so that the gas bed pressure in the tanks of both cartridges can be made to be approximately the same. This makes it possible to stabilize the pressure of the gas fuel supplied to the first gas consumer.

[0052] In a fourth embodiment, in the second embodiment, the gas fuel supply system further comprises a plurality of valves provided in the gas fuel supply line and the boil-off gas supply line, and a processing circuit that controls the plurality of valves, wherein when the processing circuit is discharging the liquefied gas from two of the plurality of cartridges, if the pressure difference between the gas bed pressures of the tanks of both cartridges is greater than or equal to a predetermined value, the plurality of valves may be controlled so that the boil-off gas is discharged only from the cartridge with the higher gas bed pressure. With this configuration, the pressure of the tank with the higher gas bed pressure can be reduced, so that the gas bed pressures of the tanks of both cartridges can be made approximately the same. This makes it possible to stabilize the pressure of the gas fuel supplied to the first gas consumer.

[0053] In a fifth aspect, in the second aspect, the gas fuel supply system further comprises a plurality of valves provided in the gas fuel supply line and the boil-off gas supply line, and a processing circuit that controls the plurality of valves, wherein when the liquefied gas is discharged from two of the plurality of cartridges, the processing circuit may control the plurality of valves so that the gas layers of the tanks of both cartridges are in communication with each other if the differential pressure of the gas layer pressure in the tanks of both cartridges is greater than or equal to a predetermined value. With this configuration, the tanks of both cartridges can be pressurized. This makes it possible to stabilize the pressure of the gas fuel supplied to the first gas consumer. [Explanation of Symbols]

[0054] 1 ship 11 Hull 12. First gas consumption unit 13. Second gas consumption unit 2. Gas fuel supply system 3 cartridges 32 tanks 33 Liquefied gas outlet pipe 35 BOG outlet pipe 4. Gas fuel supply line 41 Main channel 42 valves 43. Pump (vaporizer) 44 Intersection 5 BOG supply lines 51 Main channel 52, 53 valves 54 Forks in the road 6 relay lines 61, 63 valves 62 Vaporizer 7 Control device 71 Processing Circuit 81,84 Pressure gauge

Claims

1. A gas fuel supply system installed on a ship, Each includes a tank for storing liquefied gas and a plurality of cartridges that are detachable from the hull of the ship, A gas fuel supply line that guides the vaporized gas of liquefied gas discharged from the plurality of cartridges to a gas consumer as gas fuel, the gas fuel supply line including a plurality of branch lines connected to the plurality of cartridges, and a main flow path to which the plurality of branch lines are connected, A vaporizer provided in the main flow path, A gas fuel supply system equipped with the following features.

2. The aforementioned branch is the first branch, the aforementioned main flow path is the first main flow path, and the aforementioned gas consumer is the first gas consumer. A boil-off gas supply line that guides boil-off gas generated in the tank from the plurality of cartridges to a second gas consumer, further comprising a plurality of second branch lines connected to the plurality of cartridges, and a second main flow path to which the plurality of second branch lines are connected, according to claim 1, a gas fuel supply system.

3. The aforementioned vaporizer is the first vaporizer, A relay line that branches off from the first main channel and connects to the second main channel, A second vaporizer is provided in the aforementioned relay line, Multiple valves provided in the gas fuel supply line, the boil-off gas supply line, and the relay line, The system further comprises a processing circuit for controlling the plurality of valves, The gas fuel supply system according to claim 2, wherein the processing circuit controls the plurality of valves so that when the liquefied gas is discharged from two of the plurality of cartridges, if the differential pressure of the gas layer pressure in the tanks of the two cartridges is greater than or equal to a predetermined value, the vaporized gas vaporized by the second vaporizer is supplied to the cartridge with the lower gas layer pressure in the tank.

4. Multiple valves provided in the gas fuel supply line and the boil-off gas supply line, The system further comprises a processing circuit for controlling the plurality of valves, The gas fuel supply system according to claim 2, wherein the processing circuit controls the plurality of valves so that when discharging the liquefied gas from two of the plurality of cartridges, if the differential pressure of the gas layer pressure in the tank of both cartridges is greater than or equal to a predetermined value, the boil-off gas is discharged only from the cartridge with the higher gas layer pressure in the tank.

5. Multiple valves provided in the gas fuel supply line and the boil-off gas supply line, The system further comprises a processing circuit for controlling the plurality of valves, The gas fuel supply system according to claim 2, wherein the processing circuit controls the plurality of valves so that the gas layers of the tanks of both cartridges communicate with each other when discharging the liquefied gas from two of the plurality of cartridges, if the differential pressure of the gas layer pressure of the tanks of both cartridges is greater than or equal to a predetermined value.

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