Fuel Supply System

Abstract

To provide a fuel feed system capable of suppressing manufacturing costs of a fuel tank, and hardly receiving restriction of an installation space of the fuel tank, though fuel storage capacity is large.SOLUTION: The fuel feed system for feeding liquid fuel comprises: a plurality of fuel tanks each for storing the liquid fuel, that are communicated with each other; and a support structure which supports a lower tank and an upper tank so that at least one of the fuel tanks is set as the lower tank, and at least the other one of the fuel tanks is positioned as the upper tank above the lower tank.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a fuel supply system that supplies fuel from a fuel tank. [Background technology]

[0002] 2. Description of the Related Art Conventionally, in transportation means such as vehicles and ships, and in ground facilities, fuel has been supplied from a fuel tank to equipment such as power generation equipment and engines to operate the equipment (for example, Patent Document 1).

[0003] In recent years, ammonia has attracted attention as a fuel that does not emit carbon dioxide, a greenhouse gas, and its use as a fuel for equipment in various fields has been considered. In order to use liquid ammonia as a fuel, an ammonia tank with the strength and corrosion resistance suitable for storing liquid ammonia is required.

[0004] The calorific value of ammonia is lower than that of heavy oil and liquefied natural gas (LNG), which have traditionally been used as fuels. Therefore, in order to maintain the operating time of the equipment at the same level as when these conventional fuels are used, more ammonia is required, and the volume of the fuel tank must be increased compared to conventional fuels.

[0005] On the other hand, in order to increase the capacity of an ammonia tank, it is necessary to increase the strength of the steel material from which the tank is made. To achieve this, measures such as increasing the thickness of the steel material or using high-strength steel material can be considered. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent Publication No. 2021-126941 Summary of the Invention [Problem to be solved by the invention]

[0007] However, there is a limit to the thickness of steel that material manufacturers can manufacture. In addition, for materials used in ships, for example, the "International Code for the Construction and Equipment of Ships Carrying Liquefied Gas in Bulk" (IGC Code) restricts the upper limit of the physical property value indicating the strength of the material from the viewpoint of preventing stress corrosion cracking caused by ammonia. The IGC Code allows the use of high-strength materials that exceed the upper limit of the physical property value indicating the strength of the material, provided that heat treatment is performed to relieve residual stress after the completion of the ammonia tank. However, the larger the ammonia tank, the larger the heat treatment equipment required, and the longer the construction period, the higher the manufacturing cost of the ammonia tank is expected to be. In addition, there is a problem that the larger the ammonia tank, the more likely it is to be restricted by the installation space.

[0008] SUMMARY OF THE PRESENT DISCLOSURE An object of the present invention is to provide a fuel supply system that can reduce the manufacturing costs of the fuel tank and is not easily restricted by the installation space of the fuel tank, despite having a large fuel storage capacity. [Means for solving the problem]

[0009] The present disclosure encompasses the following aspects. Aspect 1 1. A fuel supply system for supplying a liquid fuel, comprising: a plurality of fuel tanks communicating with each other for storing the liquid fuel; a support structure that supports the lower tank and the upper tank so that at least one of the fuel tanks is a lower tank and at least one other of the fuel tanks is positioned above the lower tank as an upper tank.

[0010] Aspect 2 2. The fuel supply system of claim 1, further comprising a liquid phase pipe connected to the fuel tank so that the liquid fuel stored in the fuel tank is drawn from the fuel tank and transported.

[0011] Aspect 3 the liquid phase pipe has a common flow path portion which serves as a flow path for the liquid fuel that is extracted from each of the fuel tanks and joined together, 3. The fuel supply system according to claim 2, further comprising a pump disposed in the common flow path portion for transporting the liquid fuel.

[0012] Aspect 4 The fuel supply system according to aspect 2 or 3, further comprising a gas phase pipe connected to the fuel tank so as to communicate gas phase spaces in the fuel tank with each other.

[0013] Aspect 5 The fuel supply system of embodiment 4, further comprising a compressor disposed in the gas phase piping for drawing in gas from at least one of the gas phase spaces and sending it to at least one other gas phase space.

[0014] Aspect 6 a plurality of control valves for opening and closing a flow path of the gas phase pipe are provided at a connection end of the gas phase pipe connected to the fuel tank, The fuel supply system of aspect 4 or 5, further including a control device that controls the control valve so that the flow path of the gas phase piping is open during at least one of a period during which the liquid fuel is being poured into the fuel tank and a period during which the liquid fuel is being removed from the fuel tank.

[0015] Aspect 7 The fuel supply system of claim 6, wherein the control device controls the control valve so that the flow path is open in the portion of the gas phase piping connecting the upper tank and the lower tank while the liquid fuel is being removed from each of the upper tank and the lower tank.

[0016] Aspect 8 The fuel tank has a shape that extends in one direction, The support structure includes a plurality of plate-shaped supports arranged at a distance from each other in a direction parallel to the one direction, 8. The fuel supply system of claim 7, wherein each of the plate-shaped supports has a plurality of engaging portions that mate with each of the fuel tanks so that the fuel tanks are arranged extending parallel to each other.

[0017] Aspect 9 A fuel supply system as described in aspect 8, wherein the plate-shaped support body has an interference member arranged in the gap between the lower tank and the mating portion into which the lower tank is fitted, and is configured to prevent contact between the lower tank and the edge of the mating portion on the upper tank side.

[0018] Aspect 10 10. The fuel supply system of any one of aspects 1 to 9, wherein the liquid fuel is liquid ammonia. Effect of the Invention

[0019] According to the fuel supply system of the above aspect, even though the fuel storage capacity is large, the manufacturing cost of the fuel tank can be suppressed, and there is little restriction on the installation space of the fuel tank. [Brief description of the drawings]

[0020] [Figure 1] FIG. 1 is a diagram illustrating an example of a fuel supply system according to an embodiment. [Diagram 2] 6 is a cross-sectional view of the fuel supply system shown in FIG. 5 along line II-II. [Diagram 3] FIG. 4 is a diagram showing an example of a gas flow in a gas phase pipe. [Figure 4] 6 is a cross-sectional view of the fuel supply system shown in FIG. 5 along the line IV-IV. [Diagram 5] FIG. 2 is a top view showing the fuel tank and the support structure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] FIG. 1 shows an example of a fuel supply system according to an embodiment. The fuel supply system 1 is a system for supplying liquid fuel. The liquid fuel may be a liquefied fuel such as liquid ammonia, LNG (Liquefied Natural Gas), or LPG (Liquefied Petroleum Gas), or a fuel that is liquid at room temperature such as heavy oil or light oil. Among these, liquid ammonia is preferably used because it does not emit carbon dioxide, a greenhouse gas, when burned.

[0022] Fig. 2 shows a cross section taken along line II-II of the fuel supply system 1 shown in Fig. 5, which will be referred to later, and Fig. 4 shows a cross section taken along line IV-IV. Fig. 5 shows a top view of upper tanks 13, 14 and a support structure 20, which will be described later. The fuel supply system 1 includes a plurality of fuel tanks 11, 12, 13, 14 (Fig. 2) and a support structure 20 (Figs. 4 and 5).

[0023] The fuel tanks 11-14 are tanks that are connected to each other and are used to store liquid fuel. By providing a plurality of fuel tanks 11-14, the storage capacity of the liquid fuel in the fuel supply system 1 as a whole is increased, and a large amount of fuel can be supplied to the destination equipment, such as an engine or a power generation device. Among the liquid fuels, the calorific value of ammonia is lower than that of heavy oil or LNG, and therefore more ammonia is required to achieve the same operating time of the equipment as when heavy oil or LNG is used as fuel. Therefore, a large storage capacity is effective, particularly when liquid ammonia is used as the liquid fuel.

[0024] In general, in order to manufacture a large-volume fuel tank, it is necessary to increase the strength of the steel material that is the material of the tank. To achieve this, measures such as increasing the thickness of the steel material or using high-strength steel material can be considered, but as described above, various problems are expected. In the fuel supply system 1, by providing multiple fuel tanks 11-14, even if the volume of each fuel tank is reduced, the overall storage capacity is large, so each fuel tank can be made relatively small. Therefore, it is not necessary to excessively increase the strength of the material of the fuel tank, and it is not necessary to excessively increase the thickness of the steel material or use steel material with excessively high strength. In addition, since it is not necessary to use a large fuel tank to ensure the storage capacity, a large heat treatment facility is not required when performing heat treatment to remove residual stress generated in the manufacturing process of the fuel tank. Alternatively, it is possible to avoid the lengthening of the construction period caused by performing heat treatment for each block into which a large fuel tank is divided. In this way, by providing multiple fuel tanks 11-14 and making each fuel tank small, the manufacturing cost of the fuel tank can be reduced. If the fuel tank can be made smaller, large-scale facilities are not required to manufacture the fuel tank, and the number of manufacturers capable of manufacturing the fuel tanks increases, so that the production period can be shortened by placing orders for the manufacture of the multiple fuel tanks 11 to 14 in a distributed manner. This also reduces the manufacturing costs of the fuel tanks.

[0025] The number of fuel tanks included in the fuel supply system 1 is four in the illustrated example, but is not limited thereto and may be two, three, five, six or more. The material of the fuel tank is preferably steel. The thickness of the material of the fuel tank is, for example, 5 to 39.9 mm when the material of the fuel tank is steel.

[0026] The support structure 20 is a structure that supports the lower tank and the upper tank so that at least one of the fuel tanks 11-14 is a lower tank and at least one of the fuel tanks is located above the lower tank as an upper tank. In the example shown in FIG. 2, the fuel tanks 11 and 12 are supported as lower tanks and the fuel tanks 13 and 14 are supported as upper tanks above the lower tanks 11 and 12. In this way, the fuel tanks 11-14 can be arranged vertically stacked, so that the fuel tanks 11-14 can be installed in a space-saving manner. Therefore, for example, the fuel tanks 11-14 can be installed in a relatively narrow space near the stern where the living quarters of the ship are located, and the installation space is less likely to be restricted. This effect is effectively exhibited by the fuel tanks 11-14 being made smaller as described above. Arranging the fuel tanks 11-14 vertically stacked using the support structure 20 is particularly effective when liquid ammonia, which requires a large storage capacity to ensure long operating times of the equipment, is used as the liquid fuel. It is preferable that the support structure 20 supports the fuel tanks 11 to 14 so that they are stacked not only in the vertical direction but also in the lateral direction (the X direction in FIG. 2).

[0027] Despite the large fuel storage capacity, the above fuel supply system 1 can suppress the manufacturing costs of the fuel tanks 11-14 and is not subject to restrictions on the installation space of the fuel tanks 11-14. The fuel supply system 1 is suitable for supplying fuel from the fuel tanks 11-14 to equipment such as engines and power generators in means of transportation such as ships and vehicles and land facilities to operate the equipment. In the fuel supply system 1, the liquid fuel is supplied to the equipment as a supply destination in the form of liquid, gas, or supercritical fluid depending on the type of liquid fuel.

[0028] As shown in Fig. 1, the fuel supply system 1 preferably includes a liquid phase pipe 60. The liquid phase pipe 60 is connected to the fuel tanks 11-14 so that the liquid fuel stored in the fuel tanks 11-14 is taken out from the fuel tanks 11-14 and transferred. Specifically, the liquid phase pipe 60 is connected to each of the fuel tanks 11-14 and is provided so as to extend toward the equipment such as an engine or a power generator that is the supply destination. Since the fuel tanks 11-14 are connected by the liquid phase pipe 60, even if the volume of each fuel tank is small, the fuel supply system 1 as a whole can supply a large amount of liquid fuel to the equipment.

[0029] As shown in FIG. 1, the liquid phase pipe 60 preferably has a common flow path section 61 that serves as a flow path for liquid fuel extracted from each of the fuel tanks 11-14 and joined together. In this case, the fuel supply system 1 preferably includes a pump 70 for transferring the liquid fuel, which is disposed in the common flow path section 61. This allows fuel to be extracted from each of the fuel tanks 11-14, transferred, and supplied to the equipment without providing a pump for each of the fuel tanks 11-14, thereby reducing the number of pumps required for transferring the liquid fuel. The common flow path section 61 shown in FIG. 1 has a common flow path section 61a where the liquid fuel extracted from the lower tank 11 and the upper tank 13 of the fuel tanks 11-14 joins and flows, a common flow path section 61b where the liquid fuel extracted from the lower tank 12 and the upper tank 14 joins and flows, and a common flow path section 61c where the liquid fuel flowing through these common flow path sections 61a and 61b further joins and flows toward the equipment. 1, the pump 70 is disposed in the common flow path section 61c, thereby significantly reducing the number of pumps in the fuel supply system 1. Note that the notations "left side" and "right side" shown in FIG 1 correspond to the left side and right side in FIG 2. On the other hand, the pump for transferring the liquid fuel may be disposed inside each of the fuel tanks 11 to 14, instead of being disposed in the common flow path portion 61. In this case, it is preferable that the liquid phase piping 60 has a piping (not shown) in each of the fuel tanks 11 to 14 for taking out the liquid fuel sucked up by the pump to the outside of the tank. The liquid phase piping 60 is a piping (not shown) for introducing liquid fuel into the tank from the outside, and it is preferable that each of the fuel tanks 11 to 14 has a piping (feeding line) extending from the top of the tank to near the bottom of the tank.

[0030] As shown in FIG. 1, the fuel supply system 1 preferably includes a gas-phase pipe 80. The gas-phase pipe 80 is a pipe connected to the fuel tanks 11-14 so as to communicate the gas-phase spaces in the fuel tanks 11-14 with each other. In the fuel tanks 11-14, a gas-phase space is formed above the stored liquid fuel or in an empty tank. In general, the internal pressure of the gas-phase space of a fuel tank after refueling gradually increases, and therefore, an internal pressure difference may occur between the multiple tanks due to differences in the remaining amount and temperature in the tank. Here, as in the example shown in FIG. 1, the gas-phase spaces of the fuel tanks 11-14 communicate with each other, so that the gas in the gas-phase space flows from the fuel tank with a higher internal pressure to the fuel tank with a lower internal pressure, thereby suppressing the occurrence of an internal pressure difference between the multiple tanks 11-14. Since the internal pressure difference in the gas phase space between the fuel tanks is unlikely to occur, for example, when refilling the fuel tanks 11-14 with liquid fuel, it is possible to prevent a situation in which some fuel tanks are more likely to be refilled with liquid fuel than other fuel tanks, making it difficult to refill evenly. In particular, refilling of liquid ammonia needs to be performed in a sealed state between the fuel tank and the refilling hose so that vaporized ammonia does not leak to the outside, and the internal pressure of the fuel tank is likely to change during refilling, so that it is effective to prevent the internal pressure difference from occurring between the fuel tanks 11-14 as described above.

[0031] As shown in FIG. 1, the fuel supply system 1 preferably includes a compressor 90. The compressor 90 is disposed in the middle of the gas phase piping 80, and is a device for sucking gas (for example, vapor of vaporized liquid fuel) from the gas phase space of at least one of the fuel tanks 11-14 and sending it to the gas phase space of at least one of the other fuel tanks. For example, when a problem such as stress corrosion cracking occurs in one of the fuel tanks 11-14 and repair is required, it is necessary to stop using this fuel tank and ensure redundancy by making it possible to continue the supply of fuel using the remaining fuel tanks. According to the above-mentioned configuration, the compressor 90 is operated to send gas from the gas phase space of a normal fuel tank that is not experiencing a problem into the fuel tank where the problem has occurred, thereby intentionally increasing the internal pressure, so that the liquid fuel can be transferred from the fuel tank where the problem has occurred to the other normal fuel tanks via the liquid phase piping 60. As a result, even if a problem occurs in some of the fuel tanks and they become unusable, the supply of fuel can be continued using the remaining normal tanks. In this way, the fuel supply system 1 can improve redundancy.

[0032] Here, an example of the flow of gas in the gas-phase piping 80 will be described with reference to FIG. 3. For example, when a problem occurs in the fuel tank 12 and gas in the gas-phase space of the fuel tank 11 is to be sent into the fuel tank 12, the valves 80a and 80b provided in the gas-phase piping 80 are opened, the valve 80c is closed, the valves 80d and 80f are opened, the valve 80e is closed, and the valves 80h, 80i, 80k, and 80l are closed. In this state, the compressor 90 is operated to send the gas in the gas-phase space of the fuel tank 11 into the fuel tank 12 through the path indicated by the thick arrow. At this time, the valve 60f is closed, and the valves 60b and 60d are opened to keep the flow path between the fuel tank 12 and the fuel tank 14 open, so that the liquid fuel in the fuel tank 12 can be transferred into the normal fuel tank 14. Note that the gas-phase piping 80 is provided with a plurality of valves (gas-phase control valves) 80a to 80l for opening and closing the flow path in the piping, as shown in FIG. 1. 1, the liquid phase piping 60 is provided with a plurality of valves (liquid phase control valves) 60a to 60f for opening and closing the flow paths in the piping. The opening and closing operations of these valves may be controlled by a control device 100 described later, or they may be opened and closed manually.

[0033] The fuel supply system 1 preferably includes a control device 100 that controls the valves 80a-80l of the gas phase pipe 80 and the valves 60a-60f of the liquid phase pipe 60. The control device 100 preferably controls the valves 80a-80l so that the flow passage of the gas phase pipe 80 is open during at least one of the period during which the liquid fuel is being replenished into the fuel tanks 11-14 and the period during which the liquid fuel is being taken out from the fuel tanks 11-14. By opening the flow passage of the gas phase pipe 80 during these periods, it is possible to suppress the occurrence of an internal pressure difference between the multiple fuel tanks 11-14. The control device 100 includes, for example, a CPU and a memory, and controls each part of the fuel supply system 1 to perform various operations by executing a program stored in the memory. Specifically, the control device 100 controls the operation of the pump 70 and the compressor 90, and the opening and closing of the valves 80a-80l and the valves 60a-60f. The control device 100 also acquires data on measurement values ​​related to the internal pressure, liquid level, etc. of the fuel tanks 11-14, measured by instruments described below. The control device 100 is connected to each of these components. The control device 100 can be placed in a location away from the fuel tanks 11-14 and the support structure 20; for example, the fuel tanks 11-14 and the support structure 20 can be installed outdoors, and the control device 100 can be placed indoors.

[0034] While liquid fuel is being taken out from each of the lower tanks 11, 12 and the upper tanks 13, 14, the control device 100 preferably controls the valves 80a-80l to open the flow paths in the portions of the gas phase piping 80 connecting the lower tanks 11, 12 and the upper tanks 13, 14. When liquid fuel is simultaneously supplied from the fuel tanks 11-14, the liquid fuel is usually supplied from the lower tanks 11, 12 faster than the upper tanks 13, 14, causing the internal pressure to decrease. Therefore, if the gas phase spaces between the lower tanks 11, 12 and the upper tanks 13, 14 are not connected, the remaining amount of liquid fuel is likely to vary between the lower tanks 11, 12 and the upper tanks 13, 14. Therefore, as described above, it is preferable to control the flow path to be open in the portion of the gas phase piping 80 connecting the lower tanks 11, 12 and the upper tanks 13, 14, so that gas flows from the gas phase space of the upper tanks 13, 14, which has a high internal pressure, into the lower tanks 11, 12, whose internal pressure has decreased due to the supply of liquid fuel, thereby suppressing the occurrence of an internal pressure difference. This makes it possible to make the decrease in liquid fuel between the lower tanks 11, 12 and the upper tanks 13, 14 more uniform.

[0035] As shown in Figures 4 and 5, the fuel tanks 11-14 preferably have a shape that extends in one direction. The illustrated fuel tanks 11-14 have a substantially cylindrical shape, with both ends in the longitudinal direction (Y direction) having curved or spherical surfaces that protrude outward. The fuel tanks 11-14 having such a shape are preferably arranged to extend parallel to each other in order to improve the effect of reducing the restrictions on the installation space of the fuel tanks.

[0036] As described above, when the fuel tanks 11-14 have a shape extending in one direction, the support structure 20 preferably has a plurality of plate-shaped supports 21, 22 as shown in Figures 4 and 5. The plate-shaped supports 21, 22 are arranged spaced apart from each other in the longitudinal direction (Y direction) of the fuel tanks 11-14. According to the support structure 20 of this type, it is possible to minimize the space occupied by the support structure 20 while supporting the fuel tanks 11-14, which contributes to improving the effect of reducing restrictions on installation space. The number of plate-shaped supports is two in the illustrated example, but it may be three, four or more.

[0037] The plate-shaped supports 21 and 22 preferably have a plurality of fitting portions that are fitted with the fuel tanks 11 to 14, respectively, so that the fuel tanks 11 to 14 are arranged to extend parallel to one another. The plate-shaped support 21 has fitting portions 21a, 21b, 21c, and 21d, and the plate-shaped support 22 has fitting portions 22a, 22b, 22c, and 22d. In FIG. 2, the reference numerals of the main parts of the plate-shaped support 22 are followed by the reference numerals of the corresponding parts of the plate-shaped support 21 in parentheses. Among the fitting portions 21a to 21d and 22a to 22d, the lower fitting portions 21a, 21b, 22a, and 22b that are fitted with the lower tanks 11 and 12 have holes formed therein through which the lower tanks 11 and 12 are fitted so that they are arranged to pass through. Additionally, upper fitting portions 21c, 21d, 22c, 22d that fit with upper tanks 13, 14 have upwardly opening recesses formed therein into which upper tanks 13, 14 are fitted so as to be disposed from above. Plate-shaped supports 21, 22 of this type are capable of supporting the load of fuel tanks 11-14 in all areas between adjacent holes or recesses, and are therefore suitable for supporting large fuel tanks 11-14 with large volumes.

[0038] The interval between adjacent fuel tanks 11-14 supported by plate-like supports 21, 22 can be determined so as to ensure the strength of plate-like supports 21, 22 that bears the load of fuel tanks 11-14 while minimizing restrictions on installation space.

[0039] The plate-like supports 21 and 22 can be produced, for example, by joining a plurality of plate materials. In the plate-like support 22 of the example shown in Fig. 2, the plate materials arranged adjacent to each other vertically (plate materials 32a and 32b or plate materials 32d and 32e) are joined to each other via a plate material (plate material 32c) arranged horizontally, from the viewpoint of ease of production of the plate-like support 22. In the plate-like support 22 of the example shown in Fig. 2, brackets 32l and 32p are provided between plate materials that are adjacent to each other in the lateral direction and joined together, such as between plate materials 32a and 32d that are adjacent to each other on the left and right, and between plate materials 32b and 32e, in order to reinforce the strength of the plate-like support 22. In addition, brackets 32g, 32h, 32i, and 32j are provided at the center of the plate materials 32a, 32b, 32d, and 32e in the lateral direction, respectively, and brackets 32k, 32n, 32m, and 32r are provided at the end portions of the lateral ends of the plate materials 32a, 32b, 32d, and 32e that are not joined to other plate materials. Note that the brackets are not shown in Fig. 5. Similarly, in the plate-like support 21, plate members (plate members 31a, 31b or plate members 31d, 31e) arranged adjacent to each other vertically are joined to each other with a plate member (plate member 31c) arranged horizontally interposed therebetween. In the plate-like support 21, brackets 31l, 31p are provided between plate members arranged adjacent to each other in the lateral direction and joined together, such as between plate members 31a, 31d arranged adjacent to each other horizontally and between plate members 31b, 31e, and brackets 31g, 31h, 31i, 31j are provided at the lateral center of each of the plate members 31a, 31b, 31d, 31e, and brackets 31k, 31n, 31m, 31r are provided at the lateral ends of the plate members 31a, 31b, 31d, 31e that are not connected to other plate members.

[0040] Gaps between the holes and recesses of the mating parts 21a-21d, 22a-22d and the lower regions of the fuel tanks 11-14 are filled with, for example, a laid liner material (indicated by the reference characters 42a, 42b, 42c, and 42d in FIG. 2). Alternatively, the mating parts 21a-21d, 22a-22d and the lower regions of the fuel tanks 11-14 may be joined by welding after being fitted together.

[0041] The plate-like supports 21, 22 preferably have interference members (indicated by symbols 51a, 52a in FIG. 2) disposed in the gaps between the lower tanks 11, 12 and the lower joints 21a, 21b, 22a, 22b. By disposing such interference members, it is possible to prevent the lower tanks 11, 12 from coming off the lower joints 21a, 21b, 22a, 22b and coming into contact with the upper tanks 13, 14 when they are submerged or the like due to buoyancy and tending to float up. The interference members are made of, for example, the same material (for example, wood) as the liner material.

[0042] In addition, the plate-shaped supports 21, 22 and the upper tanks 13, 14 preferably have an interlocking structure that interlocks with each other. The interlocking structure includes protrusions (indicated by reference characters 13b, 14b in FIG. 2) provided on the outer wall surfaces of the upper tanks 13, 14 as floating prevention devices, locking parts 21e, 21f, 22e, 22f provided on the plate-shaped supports 21, 22, and interference members (indicated by reference characters 53a, 54a in FIG. 2) disposed between the protrusions and the locking parts. By having such an interlocking structure, it is possible to prevent the upper tanks 13, 14 from being dislodged from the upper mating parts 21c, 21d, 22c, 22d due to buoyancy when submerged, and from drifting, etc. The interference members of the interlocking structure are made of the same material (wood) as the liner material, for example, as the interference members (indicated by reference characters 51a, 52a in FIG. 2) described above.

[0043] Each of the fuel tanks 11-14 is provided with compartments 11a, 12a, 13a, and 14a isolated from the fuel tanks 11-14 as a space for accommodating pipes and valves extending from within the tank, and instruments for measuring the tank's internal pressure, liquid level, etc. In Fig. 5, the compartments 11a and 12a located at the same lateral position (X direction) as the compartments 13a and 14a are shown in parentheses.

[0044] 2, the circles inside the circles showing the outlines of the fuel tanks 11-14 indicate reinforcing members 11c, 12c, 13c, and 14c arranged inside the tanks. The reinforcing members 11c, 12c, 13c, and 14c are ring-shaped members that go around the inner wall surface of the fuel tank to support the inner wall surface from the inside, and are arranged at intervals in the longitudinal direction (Y direction).

[0045] Although the fuel supply system of the present invention has been described above, the present invention is not limited to the above-described embodiment, and various improvements and modifications may be made without departing from the spirit and scope of the present invention. [Explanation of symbols]

[0046] 1 Fuel supply system 11, 12 Lower tank (fuel tank) 13, 14 Upper tank (fuel tank) Sections 11a, 12a, 13a, 14a (storage space for instruments, etc.) 13b, 14b Protrusions (anti-floating device) 11c, 12c, 13c, 14c Reinforcing members 20 Support structure 21, 22 Plate-shaped support 21a, 21b, 22a, 22b lower mating part 21c, 21d, 22c, 22d Upper mating part 21e, 21f, 22e, 22f Locking part 31a, 31b, 31c, 31d, 31e Plate material of plate-shaped support 21 31g, 31h, 31i, 31j, 31k, 31l, 31m, 31n, 31p, 31r Brackets of plate-shaped support 21 32a, 32b, 32c, 32d, 32e Plate material of plate-shaped support 22 32g, 32h, 32i, 32j, 32k, 32l, 32m, 32n, 32p, 32r Brackets of plate-shaped support 22 41a, 41b, 41c, 41d: liner material of plate-shaped support 21 42a, 42b, 42c, 42d: liner material of plate-shaped support 22 51a, 52a, 53a, 54a Interference members 60 Liquid phase piping 60a, 60b, 60c, 60d, 60e, 60f Liquid phase control valve 61 Common flow path section 61a, 61b, 61c Common flow path section 70 Pump 80 Gas phase piping 80a, 80b, 80c, 80d, 80e, 80f, 80g, 80h, 80i, 80j, 80k, 80l Gas phase control valve 90 Compressor 100 Control device

Claims

1. A ship fuel supply system for supplying liquid fuel to equipment of a ship, comprising: a plurality of fuel tanks communicating with each other for storing the liquid fuel; a support structure that supports the lower tank and the upper tank such that at least one of the fuel tanks is a lower tank and at least one other of the fuel tanks is located above the lower tank as an upper tank, The fuel tank has a shape that extends in one direction, The support structure includes a plurality of plate-shaped supports arranged at a distance from each other in a direction parallel to the one direction, each of the plate-shaped supports has a plurality of fitting portions that are fitted with the respective fuel tanks so that the fuel tanks are disposed extending parallel to each other; a lower fitting portion, among the plurality of fitting portions, into which the lower tank is fitted, has a through hole through which the lower tank is disposed by penetrating the plate-shaped support body, and a peripheral gap surrounding the lower tank is formed between an edge portion of the lower fitting portion that contacts the through hole and the lower tank disposed in the through hole, A fuel supply system characterized in that the plate-shaped support body has an interference member arranged in the gap region so as to prevent contact between the lower tank and the portion of the edge that contacts the gap region on the upper tank side of the circumferential gap.

2. 2. The fuel supply system according to claim 1, further comprising a liquid phase pipe connected to the fuel tank so that the liquid fuel stored in the fuel tank is taken out of the fuel tank and transported.

3. the liquid phase pipe has a common flow path portion which serves as a flow path for the liquid fuel that is extracted from each of the fuel tanks and joined together, The fuel supply system according to claim 2 , further comprising a pump disposed in the common flow passage portion for transporting the liquid fuel.

4. 4. The fuel supply system according to claim 2, further comprising a gas phase pipe connected to the fuel tank so as to communicate gas phase spaces in the fuel tank with each other.

5. 5. The fuel supply system according to claim 4, further comprising a compressor disposed in the gas phase piping for sucking gas from at least one of the gas phase spaces and sending the gas to at least one other gas phase space.

6. a plurality of control valves for opening and closing a flow path of the gas phase pipe are provided at a connection end of the gas phase pipe connected to the fuel tank, 5. The fuel supply system according to claim 4, further comprising a control device that controls the control valve so that the flow path of the gas phase piping is open during at least one of a period during which the liquid fuel is being put into the fuel tank and a period during which the liquid fuel is being taken out of the fuel tank.

7. 7. The fuel supply system according to claim 6, wherein the control device controls the control valve so that the flow path is open in a portion of the gas phase piping connecting the upper tank and the lower tank while the liquid fuel is being taken out of each of the upper tank and the lower tank.

8. The plate-like support further has a liner material disposed in a gap region of the circumferential gap opposite the gap region with respect to the lower tank, the liner material supporting the lower tank disposed in the through hole, 2. The fuel delivery system of claim 1, wherein the liner material and the interference member are made of wood.

9. Among the plurality of fitting portions, the upper fitting portion into which the upper tank is fitted has a recess that opens upward so that the upper tank is positioned from above, the plate-shaped support body and the upper tank have an interlocking structure in which they interlock with each other, When the interference member is referred to as a first interference member, the meshing structure is A protrusion provided on an outer wall surface of the upper tank; a locking portion provided on the plate-shaped support member to which the protrusion is locked from below; 9. The fuel supply system according to claim 1, further comprising: a second interference member disposed between the projection and the engaging portion.

10. 9. The fuel supply system according to claim 1, wherein the liquid fuel is liquid ammonia.

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