Fuel supply device

Abstract

A fuel supply device according to the present invention comprises: a housing that includes a fuel supply port through which a liquid fuel is supplied, a gas supply port through which a gas containing oxygen is supplied, and a fuel discharge port through which the liquid fuel is discharged; and a tube unit that is accommodated in the housing and that allows the gas to pass therethrough to reach the liquid fuel, wherein a plurality of tubes included in the tube unit are each constituted by a plurality of layers arranged in the radial direction of that tube, the plurality of layers include a porous layer and a non-porous layer which allows the gas to pass therethrough but which does not allow the liquid fuel to pass therethrough, and the non-porous layer is positioned between the porous layer and a region in the housing where the liquid fuel is accommodated.

Description

fuel supply device

[0001] The present disclosure relates to a fuel supply system.

[0002] Patent Document 1 discloses a fuel supply device intended to feed fuel into an engine after dissolving air in the fuel.

[0003] Japanese Patent Application Laid-Open No. 2019-19815

[0004] An object of one aspect of the present disclosure is to provide a fuel supply device that can dissolve an oxygen-containing gas in a liquid fuel well for a long period of time.

[0005] A fuel supply device according to one aspect of the present disclosure includes a housing having a fuel supply port through which liquid fuel is supplied, a gas supply port through which oxygen-containing gas is supplied, and a fuel outlet port through which the liquid fuel is discharged, and a tube unit housed in the housing and permeable to gas, wherein each of the plurality of tubes included in the tube unit is composed of a plurality of layers arranged along the radial direction of the plurality of tubes, the plurality of layers including a porous layer and a non-porous layer that is permeable to gas but not to liquid fuel, and the non-porous layer is located between an area in the housing where the liquid fuel is contained and the porous layer.

[0006] This fuel supply device is configured to allow the supply of oxygen-containing gas to the liquid fuel supplied from the fuel supply port into the housing using a tube unit. Each of the multiple tubes included in the tube unit is composed of multiple layers. The multiple layers include a porous layer and a non-porous layer that is permeable to gas but not to liquid fuel, and the non-porous layer is located between the porous layer and the area in the housing where the liquid fuel is stored. This reduces the likelihood of the liquid fuel coming into contact with the porous layer, making clogging of the porous layer less likely to occur. This allows the oxygen-containing gas to efficiently permeate the multiple tubes over a long period of time, and therefore the gas is efficiently supplied to the liquid fuel over a long period of time. Therefore, by using the fuel supply device, it is possible to efficiently dissolve the oxygen-containing gas in the liquid fuel over a long period of time.

[0007] One ends of the tubes may be connected to the gas supply port, and the non-porous layer may be located radially outward of the porous layer. In this case, by implementing an external perfusion method in which liquid fuel flows outside the tubes, it is possible to effectively dissolve oxygen-containing gas in the liquid fuel for a long period of time. The housing may have a first passage extending from the gas supply port to the interior of the housing, and the tube unit may have a first bundling part bundling one ends of the tubes and a first metal ring having a hole through which the first bundling part is passed, and at least a portion of the first bundling part may extend into the first passage into which the first metal ring is fitted. In this case, gas and liquid leakage between one end of each tube and the gas supply port may be prevented.

[0008] One ends of the tubes may be connected to a fuel supply port, and the other ends of the tubes may be connected to a fuel outlet, and the non-porous layer may be located radially inward of the porous layer. In this case, by implementing an internal perfusion system in which liquid fuel flows inside the tubes, it is possible to effectively dissolve an oxygen-containing gas in the liquid fuel for a long period of time. The housing may have a first passage extending from the fuel supply port to the interior of the housing and a second passage extending from the fuel outlet to the interior of the housing. The tube unit may have a first bundling part bundling one ends of the tubes, a second bundling part bundling the other ends of the tubes, a first metal ring having a hole through which the first bundling part is passed, and a second metal ring having a hole through which the second bundling part is passed, and at least a portion of the first bundling part may be inserted into the first passage in which the first metal ring is fitted, and at least a portion of the second bundling part may be inserted into the second passage in which the second metal ring is fitted. In this case, gas and liquid leakage can be prevented between one end of each tube and the fuel supply port, and between the other end of each tube and the fuel supply port.

[0009] The plurality of layers may further include a second non-porous layer, and the porous layer may be located between the non-porous layer and the second non-porous layer in the radial direction. In this case, in both the external perfusion method and the internal perfusion method, it is possible to satisfactorily dissolve the oxygen-containing gas in the liquid fuel for a long period of time.

[0010] The fuel supply device may further include a pressurizing mechanism for pressurizing the inside of the housing, in which case the amount of oxygen dissolved in the liquid fuel can be increased.

[0011] The gas may be air or oxygen, and the fuel supply device may further include a gas supply mechanism that supplies the gas into the housing while pressurizing it. In this case, even when the gas is air or oxygen, oxygen can be dissolved in the liquid fuel.

[0012] The housing may be made of stainless steel, tin-galvanized steel, aluminized steel, aluminum, or galvanized steel, which increases the durability of the housing.

[0013] According to one aspect of the present disclosure, it is possible to provide a fuel supply device that can dissolve an oxygen-containing gas in a liquid fuel well for a long period of time.

[0014] FIG. 1 is a schematic configuration diagram of a combustion system including a fuel supply device according to an embodiment. FIG. 2 is a schematic cross-sectional view showing an air intake device according to an embodiment. FIG. 3 is a schematic perspective view showing a tube unit according to an embodiment. FIG. 4 is a schematic end view showing a tube unit according to an embodiment. FIG. 5 is a schematic cross-sectional view taken along line A-A shown in FIG. 4. FIG. 6 is a schematic cross-sectional view showing a tube according to this embodiment. FIG. 7(a) is a schematic cross-sectional view of a tube according to another example, and FIG. 7(b) is a schematic cross-sectional view of a tube according to yet another example. FIG. 8 is a schematic cross-sectional view showing an air intake device according to a modified example. FIG. 9 is a schematic cross-sectional view of a detail of an air intake device according to yet another modified example.

[0015] Hereinafter, an embodiment of a fuel supply device according to the present disclosure will be described with reference to the drawings. In the description of the drawings, the same or corresponding elements are designated by the same reference numerals, and duplicate explanations will be omitted as appropriate. The drawings may be partially simplified or exaggerated to facilitate understanding, and the dimensional ratios and the like are not limited to those shown in the drawings.

[0016] FIG. 1 is a schematic diagram of a combustion system including a fuel supply device according to this embodiment. As shown in FIG. 1 , the combustion system 100 is a group of devices for burning liquid fuel, and includes a fuel tank 101, a liquid supply device 102, an air supply device 103, a gas supply device 104, a dissolved oxygen sensor 105, and a combustion device 106. In the combustion system 100, the fuel tank 101 is located at the most upstream position, and the combustion device 106 is located at the most downstream position. The fuel supply device included in the combustion system 100 only needs to include at least the air supply device 103. The fuel supply device itself supplies liquid fuel to a predetermined device, but is not limited to this. The fuel supply device does not necessarily have a mechanism for moving the liquid fuel. In this case, the fuel supply device may supply liquid fuel to the combustion device 106 by the operation of an external device, such as a pump, separate from the fuel supply device. In this embodiment, the fuel supply device includes the liquid supply device 102, the air supply device 103, and the gas supply device 104. Although not shown, the combustion system 100 may include a device (flow rate sensor) that detects the amount of liquid fuel discharged from the fuel tank 101 in a predetermined period of time.

[0017] The fuel tank 101 is a device that stores liquid fuel and is, for example, a container made of resin or alloy. The liquid fuel stored in the fuel tank 101 is a liquid that burns with supplied oxygen and may be alcohol such as ethanol or methanol, or a petroleum product such as diesel, kerosene, heavy oil, gasoline, or kerosene. The alcohol may be biofuel, synthetic fuel (e-fuel), or the like. The material of the fuel tank 101 is appropriately determined depending on the type of liquid fuel, and may be, for example, an alloy or resin. For example, if the fuel tank 101 is made of an alloy, the fuel tank 101 may be made of stainless steel, tin-galvanized steel, aluminum-plated steel, aluminum, or zinc-plated steel. If the fuel tank 101 is made of resin, the fuel tank 101 may be made of polyolefin such as high-density polyethylene, glass fiber-reinforced plastic, or rubber. For example, if the liquid fuel is ethanol, the fuel tank 101 is made of tin-galvanized steel, high-density polyethylene, etc. For example, if the liquid fuel is a petroleum product, the fuel tank is made of aluminized steel, aluminum, high-density polyethylene, etc.

[0018] The liquid sending device 102 is a device that sends liquid fuel in the fuel tank 101 downstream, and is located downstream of the fuel tank 101. The liquid sending device 102 is, for example, a fuel pump, and is located in a fuel flow path that connects the fuel tank 101 and the air supply device 103. When the liquid sending device 102 supplies liquid fuel to the air supply device 103, the inside of the air supply device 103 can be pressurized. In this case, the liquid sending device 102 functions as a pressurizing mechanism that pressurizes the inside of the housing 4 of the air supply device 103 (see FIG. 2 described later).

[0019] The air supply device 103 is a device that supplies a gas containing oxygen to the supplied liquid fuel, and is located downstream of the liquid delivery device 102. The air supply device 103 is supplied with the liquid fuel delivered from the fuel tank 101 by the liquid delivery device 102, and is a device that discharges the supplied liquid fuel downstream. In this embodiment, the air supply device 103 supplies at least oxygen to the liquid fuel, thereby dissolving at least oxygen in the liquid fuel. The air supply device 103 is located between the liquid delivery device 102 and the dissolved oxygen sensor 105 in the combustion system 100. A specific description of the air supply device 103 will be given later.

[0020] The gas supply device 104 is a device that supplies a gas containing oxygen to the gas supply device 103. The gas may be oxygen gas or air. The oxygen contained in the gas is １６ Not limited to O only, １７ O and １８ O. From the viewpoint of dissolving oxygen in the gas supply device 103, the gas supply device 104 may pressurize the gas and supply it into the housing 4 of the gas supply device 103 (see FIG. 2 described later). In this case, the gas supply device 104 functions as a gas supply mechanism that pressurizes the gas and supplies it into the housing 4. In addition, the gas supply device 104 can also function as a pressurization mechanism that pressurizes the inside of the housing 4. When the gas is oxygen gas, the gas supply device 104 has at least a device that stores the oxygen gas. When the gas is air, the gas supply device 104 has at least a recovery mechanism that recovers the air.

[0021] The dissolved oxygen sensor 105 is a device that measures the amount of oxygen dissolved in the liquid fuel, and is located downstream of the gas supply device 103. Depending on the measurement result of the dissolved oxygen sensor 105, the amount of gas supplied per unit time to the gas supply device 103 by the gas supply device 104 may vary.

[0022] The combustion device 106 is a device that combusts the liquid fuel supplied from the air supply device 103, and is, for example, an internal combustion engine, a heating appliance, a burner, etc. Internal combustion engines include automobile engines, marine engines, aircraft engines, construction machinery, and generators. When the combustion device 106 burns light oil, heavy oil, kerosene, biofuel, synthetic fuel (e-fuel), etc. as liquid fuel, the combustion efficiency within the combustion device 106 tends to improve, and therefore the amount of particulate matter (PM) emitted from the combustion device 106 can be reduced.

[0023] Fig. 2 is a schematic cross-sectional view showing an air supply device according to this embodiment. As shown in Fig. 2, the air supply device 103 includes a hollow fiber membrane module for dissolving an oxygen-containing gas in a fuel, and more specifically, includes a tube unit 3 in which a plurality of tubes 2 are bundled together, and a housing 4 that houses the tube unit 3. In the air supply device 103, the plurality of tubes 2 included in the tube unit 3 divide the interior of the housing 4 into a first region, which is the internal space 2a of each of the plurality of tubes 2 (see Fig. 5 described later), and a second region, which is the space 4b outside the plurality of tubes 2.

[0024] The first region is a region to which liquid fuel is supplied from the liquid delivery device 102, and the second region is a region to which gas containing oxygen is supplied from the gas supply device 104. In this embodiment, in the gas supply device 103, liquid is supplied to the internal space 2a (first region) of each of the plurality of tubes 2, and gas is supplied to the space 4b (second region) outside the plurality of tubes 2, thereby dissolving oxygen in the liquid fuel. Thus, the internal space 2a is the first region in the housing 4 where the liquid fuel is accommodated, and the space 4b is the second region in the housing 4 where the gas is accommodated.

[0025] The tube 2 is a tubular hollow fiber membrane that is permeable to gas but not to liquid fuel. The tube 2 is made of, for example, a fluorine membrane. However, the material and shape of the tube 2 can be changed as appropriate. Examples of materials for the tube 2 include polytetrafluoroethylene (PTFE), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), tetrafluoroethylene-ethylene copolymer (ethylene copolymer resin) (ETFE), polychlorotrifluoroethylene (PCTFE), amorphous fluoropolymer (non-crystalline fluororesin; AF), fluororesins such as polyvinylidene fluoride (PVDF), polypropylene (PP), polymethylpentene (PMP), silicone, polyimide, and polyamide. Examples of amorphous fluoropolymers include Teflon (registered trademark) AF.

[0026] Fig. 3 is a schematic perspective view showing a tube unit according to this embodiment. Fig. 4 is a schematic end view showing a tube unit according to this embodiment. Fig. 5 is a cross-sectional view taken along line A-A in Fig. 4. Note that Figs. 3 and 4 illustrate a case in which the tube unit 3 is composed of seven tubes 2. However, the number of tubes 2 included in the tube unit 3 is not particularly limited. For example, the number of tubes 2 constituting the tube unit 3 may be several tens or several hundreds.

[0027] The tube unit 3 is a gas-permeable member housed in a housing 4. As shown in Figures 3 to 5, in the tube unit 3, both ends of a plurality of tubes 2 are bound together. The tube unit 3 has a binding part 5 that binds together the plurality of tubes 2. The binding part 5 includes a first binding part 5A that binds together one ends of the plurality of tubes 2 and a second binding part 5B that binds together the other ends of the plurality of tubes 2.

[0028] The first binding part 5A and the second binding part 5B are attached to the housing 4. For example, the configuration of the first binding part 5A is the same as the configuration of the second binding part 5B. Therefore, in the following description, when there is no need to distinguish between the first binding part 5A and the second binding part 5B, the first binding part 5A and the second binding part 5B will be collectively described as the binding part 5. Note that the configuration of the first binding part 5A may be different from the configuration of the second binding part 5B.

[0029] The bundling part 5 includes an outer tube 6 into which the ends of the plurality of tubes 2 are inserted, and a sealing part 7 filled between the ends of the plurality of tubes 2 and the outer tube 6. The outer tube 6 is the outermost layer of the bundling part 5. The outer tube 6 has, for example, a cylindrical shape. The outer tube 6 is attached to the housing 4. The outer tube 6 is made of, for example, a fluororesin such as PFA or PTFE.

[0030] The sealing portion 7 bundles the ends of the multiple tubes 2 and seals the gap between the ends of the multiple tubes 2 and the outer tube 6. The sealing portion 7 does not fill the internal spaces 2a of each of the multiple tubes 2. The sealing portion 7 fills the gaps between the multiple tubes 2 and between the tubes 2 and the outer tube 6. Only the internal spaces 2a of each of the multiple tubes 2 are open from the end faces of the sealing portion 7. The sealing portion 7 is made of a fluororesin such as FEP or PFA, for example.

[0031] Each of the multiple tubes 2 is composed of multiple layers 20 arranged along the radial direction of the tube 2. The "radial direction" refers to the direction toward or away from the axis of the tube in a plane perpendicular to the direction in which the tube extends. The "radial outer side" refers to the radial direction away from the axis, and the "radial inner side" refers to the radial direction toward the axis. The multiple layers 20 include a porous layer 21 and a non-porous layer 22 that is permeable to gas but not to liquid fuel. The non-porous layer 22 is located between the porous layer 21 and the region in the housing 4 where the liquid fuel is accommodated (i.e., the internal space 2a). The porous layer 21 and the non-porous layer 22 will be described in detail later.

[0032] Each end of the multiple tubes 2 bound by the sealing portion 7 may have a cylindrical portion 2b and a protruding portion 2c protruding from the cylindrical portion 2b. The cylindrical portion 2b is formed, for example, by a cylindrically extending portion extending in the extension direction of the tubes 2. The protruding portion 2c is a portion protruding radially outward from the cylindrical portion 2b. The protruding portion 2c may be, for example, a thickened portion (a bulging portion) at a portion of each end of the multiple tubes 2, or a portion of each end of the multiple tubes 2 that is curved as if pinched. At each end of the multiple tubes 2, for example, the wall is thickened at the protruding portion 2c.

[0033] For example, in the protruding portion 2c, the layer 20 located radially inward of the tube 2 among the multiple layers 20 has a thicker wall. In this case, the protruding portion 2c is formed by the layer 20 located radially inward of the tube 2 among the multiple layers 20 protruding radially outward. However, unlike the example of Figure 4, in the protruding portion 2c, the layer 20 located radially outward of the tube 2 among the multiple layers 20 may have a thicker wall. In this case, the layer 20 located radially outward of the tube 2 among the multiple layers 20 protruding radially outward is formed by the layer 20 located radially outward of the tube 2.

[0034] The number of protrusions 2c that the tube 2 has may be one or more. When the tube 2 has multiple protrusions 2c, the shapes of the multiple protrusions 2c may be the same as each other or may be different from each other. The directions in which the multiple protrusions 2c protrude may be the same as each other or may be different from each other. Note that the tube 2 does not necessarily have to have any protrusions 2c.

[0035] The direction in which the protrusions 2c protrude may be constant (constant) depending on the position in the extension direction of the tube 2, or may vary depending on the position in the extension direction of the tube 2. The protrusions 2c may be formed over the entire end of the tube 2 along the extension direction of the tube 2, or may be formed partially or intermittently along the extension direction of the tube 2. For example, at the ends of multiple tubes 2, multiple tubular portions 2b may be arranged in a close-packed structure, and the protrusions 2c may be arranged in gaps formed between the multiple tubular portions 2b. Examples of methods for forming the protrusions 2c include using a tube 2 on which the protrusions 2c are formed in advance, or filling the gaps between the ends of the multiple tubes 2 and the outer tube 6 while portions of the tube 2 are pinched out with a jig.

[0036] Returning to FIG. 2 , the housing 4 will be described in detail. As shown in FIG. 2 , the housing 4 has a housing body 11 and a lid 12. The material of the housing 4 is appropriately determined depending on the type of liquid fuel, similar to the fuel tank 101, and may be made of, for example, an alloy or resin. For example, if the housing 4 is made of an alloy, the housing 4 may be made of stainless steel, tin-galvanized steel, aluminum-plated steel, aluminum, or zinc-plated steel. If the housing 4 is made of resin, the housing 4 may be made of polyolefin such as high-density polyethylene, glass fiber reinforced plastic, or rubber. From the viewpoint of durability, the housing 4 may be made of an alloy.

[0037] The housing body 11 is a portion that houses the tube unit 3. The housing body 11 has a tubular shape, such as a cylindrical shape or a rectangular tubular shape. When the housing body 11 has a rectangular tubular shape, the appearance of the housing body 11 may be a substantially rectangular parallelepiped shape. The housing body 11 may also have a cylindrical shape with a bottom. The housing body 11 has a bottom 11b, a side 11c that extends from the bottom 11b in the direction in which the axis of the housing body 11 extends (axial direction), and an opening 11d located at the end of the side 11c opposite to the bottom 11b.

[0038] The lid 12 is a lid that is airtightly joined to the housing body 11 and closes the opening 11d of the housing body 11. The lid 12 is joined to the housing body 11 by, for example, welding, screwing, or fitting. The housing body 11 and the lid 12 may be integral with each other.

[0039] The housing 4 has a first opening 13 and a second opening 14 that communicate with the internal space 2a of the plurality of tubes 2, and a third opening 15a that communicates with a space 4b outside the plurality of tubes 2 inside the housing 4. For example, the housing main body 11 has a protrusion 11f that protrudes from the bottom 11b to the outside of the housing main body 11 and a protrusion 11g that protrudes from the side 11c to the outside of the housing main body 11. The third opening 15a is formed in the protrusion 11f. In this embodiment, the first opening 13 functions as a liquid supply port through which liquid fuel is supplied, the second opening 14 functions as a liquid outlet port through which the liquid fuel is discharged, and the third opening 15a functions as a gas supply port through which oxygen-containing gas is supplied. Therefore, in this embodiment, one end of the plurality of tubes 2 is connected to the first opening 13, which is the liquid supply port, and the other end of the plurality of tubes 2 is connected to the second opening 14, which is the liquid outlet port.

[0040] The cover 12 has, for example, a main body 12b, a first protrusion 12c protruding from the main body 12b in a direction opposite to the housing body 11, and a second protrusion 12d protruding from the main body 12b in a direction opposite to the housing body 11 at a position different from the first protrusion 12c. For example, the first protrusion 12c and the second protrusion 12d are cylindrical. For example, the first opening 13 is formed at the end of the first protrusion 12c opposite to the housing body 11, and the second opening 14 is formed at the end of the second protrusion 12d opposite to the housing body 11.

[0041] The housing 4 has a first passage 16 extending from the first opening 13 into the housing 4, and a second passage 17 extending from the second opening 14 into the housing 4. For example, the first passage 16 is formed inside the first protruding portion 12c, and the second passage 17 is formed inside the second protruding portion 12d. In this embodiment, the first passage 16 extends from the liquid supply port into the housing 4, and the second passage 17 extends from the liquid discharge port into the housing 4.

[0042] For example, the first passage 16 is defined by a first inner wall 16b extending from the first opening 13, a second inner wall 16c extending from the first inner wall 16b toward the opposite side of the first opening 13, and a third inner wall 16d extending from the second inner wall 16c toward the opposite side of the first inner wall 16b. The first inner wall 16b extends from the first opening 13 toward the housing body 11. The first opening 13 is defined by, for example, the first inner wall 16b. A first tube 18b communicating with each internal space 2a of the plurality of tubes 2 is joined to the first opening 13 by, for example, welding, screwing, or fitting, and is connected to the liquid delivery device 102.

[0043] At least a portion of the first bundling portion 5A extends into the first passage 16. For example, the first bundling portion 5A is airtightly joined to the first passage 16. That is, the first bundling portion 5A of the tube unit 3 is airtightly connected to the housing 4. The first bundling portion 5A is joined to the housing 4 (e.g., the first passage 16) by, for example, welding, screwing, or fitting. The width (e.g., diameter) of the second inner wall 16c is smaller than the width of the first inner wall 16b. For example, the first bundling portion 5A is fixed to the second inner wall 16c.

[0044] The third inner wall 16d includes, for example, an inclined surface 16f extending from the second inner wall 16c and an extending surface 16h extending from the end of the inclined surface 16f opposite the second inner wall 16c to the space 4b. The inclined surface 16f is inclined relative to the second inner wall 16c so as to widen as it moves away from the second inner wall 16c.

[0045] For example, the air supply device 103 includes a first ferrule 23A, a first metal ring 24A, and a first set screw 25A. The first ferrule 23A is made of, for example, resin. The first ferrule 23A includes, for example, a cylindrical portion 23b and an inclined cylindrical portion 23c that expands in diameter from the cylindrical portion 23b and decreases in diameter as it moves away from the cylindrical portion 23b.

[0046] The first ferrule 23A has a cylindrical shape. The first bundling part 5A is inserted into the first ferrule 23A, and the first bundling part 5A inserted into the first ferrule 23A is fixed to the housing 4. At this time, the inclined cylindrical part 23c of the first ferrule 23A is in close contact with the inclined surface 16f of the first passage 16.

[0047] The first metal ring 24A has a hole 24d through which the first binding part 5A is passed. The first metal ring 24A has, for example, an annular part 24b through which the first binding part 5A is passed and a cylindrical part 24c into which the first ferrule 23A is inserted. For example, the hole 24d is formed in each of the annular part 24b and the cylindrical part 24c. From the standpoint of durability, for example, the material of the first metal ring 24A may be the same as the material of the housing 4.

[0048] The first binding part 5A is passed through the annular part 24b and is passed through the first ferrule 23A. The inner diameter of the annular part 24b is smaller than the inner diameter of the cylindrical part 24c. The first binding part 5A is in close contact with the inner surface of the annular part 24b, and the first ferrule 23A (e.g., the cylindrical part 23b) is in close contact with the inner surface of the cylindrical part 24c.

[0049] The first set screw 25A has a cylindrical shape and the first binding portion 5A is inserted through it. The first binding portion 5A, which is inserted through the first set screw 25A, is passed through the first metal ring 24A and the first ferrule 23A. The first set screw 25A is screwed into the first passage 16 (e.g., the third inner wall 16d) with the first ferrule 23A, through which the first binding portion 5A is inserted, and the first metal ring 24A inserted into the first passage 16. Therefore, at least a portion of the first binding portion 5A is inserted into the first passage 16 into which the first metal ring 24A is fitted.

[0050] For example, the second passage 17 is defined by a first inner wall 17b extending from the second opening 14, a second inner wall 17c extending from the first inner wall 17b in a direction opposite to the second opening 14, and a third inner wall 17d extending from the second inner wall 17c in a direction opposite to the first inner wall 17b. For example, the configurations of the first inner wall 17b, the second inner wall 17c, and the third inner wall 17d are the same as the configurations of the first inner wall 16b, the second inner wall 16c, and the third inner wall 16d described above. The third inner wall 17d includes, for example, an inclined surface 17f extending from the second inner wall 17c and an extending surface 17h extending from an end of the inclined surface 17f opposite the second inner wall 17c to the space 4b.

[0051] The second opening 14 is defined by a first inner wall 17b. A second pipe 18c is joined to the second opening 14, communicating with the internal spaces 2a of each of the tubes 2. The second pipe 18c is joined to the second opening 14 by, for example, welding, screwing, or fitting, and is connected to the outside of the combustion system 100. At least a portion of the second bundling portion 5B extends into the second passage 17. The manner in which the second bundling portion 5B is joined to the second passage 17 is the same as the manner in which the first bundling portion 5A is joined to the first passage 16, for example.

[0052] For example, the air supply device 103 has a second ferrule 23B, a second metal ring 24B, and a second set screw 25B. The configurations of the second ferrule 23B, the second metal ring 24B, and the second set screw 25B are the same as the configurations of the first ferrule 23A, the first metal ring 24A, and the first set screw 25A described above. Therefore, in the following, for the second ferrule 23B, the second metal ring 24B, and the second set screw 25B, descriptions that overlap with those described above will be assigned the same reference numerals and will be omitted as appropriate.

[0053] The second binding portion 5B is inserted into the second ferrule 23B, and the second binding portion 5B inserted into the second ferrule 23B is fixed to the housing 4. The second metal ring 24B has a hole 24f through which the second binding portion 5B is inserted. The second metal ring 24B has, for example, an annular portion 24b and a tubular portion 24c, and the second binding portion 5B inserted into the annular portion 24b is inserted into the second ferrule 23B. The second binding portion 5B is in close contact with the inner surface of the annular portion 24b, and the second ferrule 23B is in close contact with the inner surface of the tubular portion 24c.

[0054] The second binding portion 5B is passed through the second set screw 25B. The second binding portion 5B, which is passed through the second set screw 25B, is passed through the second metal ring 24B and the second ferrule 23B. The second set screw 25B is screwed into the second passage 17 (e.g., the third inner wall 17d) with the second ferrule 23B, through which the second binding portion 5B is inserted, and the second metal ring 24B inserted into the second passage 17. Therefore, at least a portion of the second binding portion 5B is inserted into the second passage 17 into which the second metal ring 24B is fitted.

[0055] The third opening 15a is an opening formed to supply a gas containing oxygen to the space 4b of the housing 4. A third pipe 18d that communicates with the space 4b of the housing 4 is joined to the third opening 15a. The third pipe 18d is joined to the third opening 15a by, for example, welding, screwing, or fitting, and is connected to the gas supply device 104.

[0056] The air supply device 103 has a plurality of wrappers 26. For example, the plurality of tubes 2 have a ring portion 2d that is formed into a ring shape inside the housing 4. The plurality of tubes 2 extending from the first bundling portion 5A are bent into a ring shape at the ring portion 2d, and then extend from the ring portion 2d to the second bundling portion 5B.

[0057] The wrapper straps 26, for example, bundle the plurality of tubes 2 at the annular portion 2d. For example, the plurality of wrapper straps 26 are lined up along the annular portion 2d to bundle the plurality of tubes 2. As an example, four wrapper straps 26 are lined up at equal intervals along the annular portion 2d.

[0058] An example of a method for supplying gas to a liquid fuel will be described below. First, the liquid fuel is supplied to the internal space 2a of the tube 2 by the liquid supply device 102 connected to the first pipe 18b. Simultaneously with the supply of the liquid fuel, a gas containing oxygen is supplied to the space 4b of the housing 4 by the gas supply device 104 connected to the third pipe 18d. At this time, the inside of the housing 4 is pressurized. Therefore, as the liquid fuel passes through the internal spaces 2a of the plurality of tubes 2, the gas that has permeated each tube 2 is supplied to the liquid fuel. This allows the liquid fuel to be supplied with gas (particularly, oxygen to be dissolved in the liquid fuel). The supplied liquid fuel is then discharged to the second pipe 18c. Through the above steps, the series of steps of the gas supply method is completed.

[0059] Next, the multiple layers 20 of the tube 2 will be described with reference to Fig. 6. Fig. 6 is a schematic cross-sectional view showing a tube according to this embodiment. As shown in Fig. 6, in the tube 2, the non-porous layer 22 is located radially inward of the porous layer 21.

[0060] The porous layer 21 functions as a support layer for the tube 2. The porous layer 21 is, for example, a porous membrane. As an example, the porous layer 21 is produced by melt-extruding the material that constitutes the porous layer 21 into a tubular shape. For example, the thickness of the porous layer 21 at the protruding portion 2 c of the tube 2 is greater than the thickness of the porous layer 21 in the portion other than the protruding portion 2 c of the tube 2.

[0061] The non-porous layer 22 is a member for preventing contact between the liquid fuel and the porous layer 21, and is a thin film thinner than the porous layer 21. The non-porous layer 22 is formed on the inner circumferential surface of the porous layer 21 by a dipping method. The thickness of the non-porous layer 22 is, for example, 1 μm. The non-porous layer 22 is also referred to as a skin layer. For example, the pore diameter of the non-porous layer 22 is 1 nm or less. Therefore, the non-porous layer 22 has high gas permeability while blocking the passage of liquid fuel. For example, the thickness of the non-porous layer 22 at the protruding portion 2 c of the tube 2 is the same as the thickness of the non-porous layer 22 in the portion other than the protruding portion 2 c of the tube 2.

[0062] Next, the effects achieved by the fuel supply device according to this embodiment will be described. In the air supply device 103 included in the fuel supply device described above, the tube unit 3 is configured to allow oxygen-containing gas to be supplied to the liquid fuel supplied into the tubes 2 from the first opening 13, which is the fuel supply port. Each of the multiple tubes 2 included in the tube unit 3 is composed of multiple layers 20. The multiple layers 20 include a porous layer 21 and a non-porous layer 22 that is permeable to gas but not to liquid fuel. The non-porous layer 22 is located inside the porous layer 21. Therefore, by implementing an internal perfusion method in which liquid fuel flows inside the tubes 2, the liquid fuel is less likely to come into contact with the porous layer 21, making clogging of the porous layer 21 less likely to occur. Therefore, oxygen-containing gas can easily permeate the multiple tubes 2 for a long period of time, and the gas is also efficiently supplied to the liquid fuel for a long period of time. Therefore, by using the fuel supply device described above, it is possible to effectively dissolve oxygen-containing gas in the liquid fuel for a long period of time.

[0063] In addition, by using the fuel supply device, liquid fuel with a higher oxygen content than usual is supplied to the combustion device 106, which is located downstream of the air intake device 103. The oxygen dissolved in the liquid fuel acts to support the combustion of the liquid fuel. This reduces the rate at which the liquid fuel remains unburned in the combustion device 106. Therefore, when light oil, heavy oil, kerosene, biofuel, or the like is used as the liquid fuel, it is possible to suppress the generation of PM, carbon monoxide, and the like that accompanies unburned liquid fuel. Furthermore, regardless of the type of liquid fuel, it is also possible to improve the combustion efficiency of the liquid fuel in the combustion device 106.

[0064] In this embodiment, one ends of the tubes 2 are connected to the first opening 13, which serves as a gas supply port, and the non-porous layer 22 is located radially inward of the porous layer 21. Therefore, particularly by implementing the internal perfusion method, it is possible to effectively dissolve oxygen-containing gas in the liquid fuel for a long period of time. The housing 4 also has a first passage 16 extending from the first opening 13 to the interior of the housing 4. The tube unit 3 includes a first bundling portion 5A bundling one ends of the tubes 2 and a first metal ring 24A having a hole 24d through which the first bundling portion 5A passes. At least a portion of the first bundling portion 5A may extend into the first passage 16 into which the first metal ring 24A is fitted. In this case, gas and liquid leakage between one end of each tube 2 and the first opening 13 can be prevented. Therefore, clogging of the porous layer 21 is unlikely to occur for a long period of time.

[0065] In this embodiment, the fuel supply device may further include a liquid sending device 102 that is a pressurizing mechanism for pressurizing the inside of the housing 4. In this case, the amount of oxygen dissolved in the liquid fuel can be increased.

[0066] In this embodiment, the gas is air, and the fuel supply device may further include a gas supply device 104, which is a gas supply mechanism that pressurizes the gas and supplies it into the housing 4. In this case, even when the gas is air, oxygen can be dissolved well in the liquid fuel for a long period of time.

[0067] In this embodiment, the housing 4 may be made of stainless steel, tin-galvanized steel, aluminum-plated steel, aluminum, or zinc-plated steel, which can increase the durability of the housing 4.

[0068] 7A is a schematic cross-sectional view showing another example of a tube. As shown in FIG. 7A, the non-porous layer 22A included in the tube 2A is located radially outward of the porous layer 21. When the tube 2A described above is used, an external perfusion method in which the liquid fuel flows outside the tube 2A is implemented, making it difficult for the liquid fuel to come into contact with the porous layer 21, thereby achieving the same effects as the above embodiment.

[0069] FIG. 7B is a schematic cross-sectional view showing another example of a tube. As shown in FIG. 7B, the multiple layers 20 of the tube 2B include a porous layer 21, a non-porous layer 22, and a second non-porous layer 22B. In the tube 2B, the porous layer 21 is located radially between the non-porous layer 22 and the second non-porous layer 22B. When the tube 2B is housed in a housing 4, liquid fuel may be supplied to the internal space 2a of the tube 2A or to the space 4b of the housing 4. In this case, whether the liquid fuel flows inside the tube 2B or outside the tube 2B within the space 4b of the housing 4, the liquid fuel is less likely to come into contact with the porous layer 21, thereby achieving the same effects as the above embodiment. In other words, when the tube 2B is used, whether it is an internal perfusion system or an external perfusion system, the same effects as the above embodiment are achieved. Thus, in the tube according to the present disclosure, one end of the tube is connected to a fuel supply port or a gas supply port, and the other end of the tube is connected to a fuel exhaust port or a gas exhaust port.

[0070] An air supply device 103A according to a modified example will be described below with reference to Fig. 8. The air supply device 103A includes a ferrule 43 having a different shape from the first ferrule 23A and the second ferrule 23B, and a metal ring 44 having a different shape from the first metal ring 24A and the second metal ring 24B. The air supply device 103A has a third inner wall 16x extending in the direction in which the first protrusion 12c protrudes, and a third inner wall 17x extending in the direction in which the second protrusion 12d protrudes.

[0071] The ferrule 43 has, for example, a cylindrical portion 43b and a tapered cylindrical portion 43c whose diameter decreases with increasing distance from the cylindrical portion 43b. The metal ring 44 has an annular portion 44b that contacts the first set screw 25A (or second set screw 25B) and an inner surface 44c that slopes so that the metal ring 44 becomes thinner with increasing distance from the annular portion 44b. The ferrule 43 and the metal ring 44 enter the first passage 16 and the second passage 17, respectively, with the inner surface 44c in contact with the tapered cylindrical portion 43c. As described above, the air supply device 103A having the ferrule 43 and the metal ring 44 can also achieve the same effects as the air supply device 103 described above.

[0072] An overview of an air supply device according to another modification will be described below. The configuration of the air supply device according to this modification may be the same as that of the air supply device 103 of the above embodiment. The air supply device according to this modification is an external perfusion type device, and includes, for example, a housing and a hollow fiber membrane disposed in the interior space of the housing. The hollow fiber membrane is a tube 2A (see FIG. 7(a)) or a tube 2B (see FIG. 7(b)). In one example, the housing includes a cylindrical body serving as a main body, a first lid attached to one end of the cylindrical body, and a second lid attached to the other end of the cylindrical body. In one example, the hollow fiber membrane extends along the axial direction of the cylindrical body. In one example, the cylindrical body and the first lid are joined at a first joint. At the first joint, the cylindrical body and the first lid are joined by welding, screwing, or meshing. In one example, the cylindrical body and the second lid are joined at a second joint. At the second joint, the cylindrical body and the second lid are joined by welding, screwing, or mating. In one example, the housing has at least one gas supply port, fuel supply port, and fuel discharge port, similar to the air supply device 103 described above. The gas supply port connects the internal space of the hollow fiber membrane to the outside of the housing so as to supply oxygen-containing gas to the internal space of the hollow fiber membrane. The fuel supply port connects the outside of the housing to the internal space of the housing so as to supply liquid fuel from the outside of the housing to the internal space of the housing. The fuel discharge port connects the outside of the housing to the internal space of the housing so as to discharge liquid fuel supplied to the outside of the housing from the internal space of the housing. In one example, an air supply device according to another modified example has a first sealing portion that seals one end of the cylindrical body in the axial direction and a second sealing portion that seals the other end of the cylindrical body in the axial direction. In this case, one end of the hollow fiber membrane in the axial direction can be fixed to the first sealing portion, and the other end of the hollow fiber membrane in the axial direction can be fixed to the second sealing portion. Even when the air intake device according to the other modified example described above is used in the fuel supply device, the same effects as those of the above embodiment can be achieved.

[0073] Hereinafter, another modified example of the details of each air supply device will be described with reference to Fig. 9. Fig. 9 is a schematic cross-sectional view of a detail of an air supply device according to another modified example. The detail 110 of the air supply device shown in Fig. 9 shows a modified example of the combination of the first protrusion 12c and the first pipe 18b shown in Fig. 2 or Fig. 8, but is not limited to this. For example, the detail 110 may show a modified example of the combination of the second protrusion 12d and the second pipe 18c, or a modified example of the combination of the protrusion 11f and the third pipe 18d.

[0074] The first inner wall 116b of the passage 116 in the protrusion 112c included in the detail 110 includes an inclined surface 116j extending from the second inner wall 116c toward the opening 113, and an extended surface 116k extending from the inclined surface 116j to the opening 113. The inclined surface 116j is inclined relative to the second inner wall 116c so as to narrow as it moves away from the second inner wall 116c. In one example, the passage 116 includes a ferrule 123 that is in close contact with the inclined surface 116j, a metal ring 124, and a set screw 125 that is screwed into the passage 116. The ferrule 123, the metal ring 124, and the set screw 125 have similar characteristics and structures to the first ferrule 23A, the first metal ring 24A, and the first set screw 25A, respectively. Here, a tube 118b connected to an external device of the air supply device (e.g., the liquid delivery device 102, the gas supply device 104, the combustion device 106, etc. shown in FIG. 1 ) is inserted through each of the ferrule 123, the metal ring 124, and the set screw 125. Thus, at least a portion of the tube 118b enters the passage 116 into which the metal ring 124 is fitted.

[0075] By utilizing the above-described detail 110, gas and liquid leakage can be prevented between the portion of pipe 118b that enters passage 116 and opening 113. This improves the airtightness and liquid-tightness of the air supply device. Furthermore, by replacing detail 110 not only with the combination of first protrusion 12c and first pipe 18b, but also with at least one of the combination of second protrusion 12d and second pipe 18c and the combination of protrusion 11f and third pipe 18d, the airtightness and liquid-tightness of the air supply device can be further improved.

[0076] A fuel supply device according to one aspect of the present disclosure is, for example, as described in [1] to [9] below, and has been described in detail based on the above embodiment and the above modified examples. [1] A fuel supply device comprising: a housing having a fuel supply port through which liquid fuel is supplied, a gas supply port through which oxygen-containing gas is supplied, and a fuel outlet port through which the liquid fuel is discharged; and a tube unit housed in the housing and permeable to the gas, wherein each of a plurality of tubes included in the tube unit is constituted by a plurality of layers arranged along a radial direction of the plurality of tubes, the plurality of layers including a porous layer and a non-porous layer that is permeable to the gas but not to the liquid fuel, the non-porous layer being located between a region in the housing where the liquid fuel is stored and the porous layer. [2] The fuel supply device according to [1], wherein one ends of the plurality of tubes are connected to the gas supply port, and the non-porous layer is located outside the porous layer in the radial direction. [3] The fuel supply device according to [2], wherein the housing has a first passage extending from the gas supply port into the housing, the tube unit has a first bundling part bundling one ends of the plurality of tubes and a first metal ring having a hole through which the first bundling part is passed, and at least a part of the first bundling part enters the first passage into which the first metal ring is fitted. [4] The fuel supply device according to [1], wherein one ends of the plurality of tubes are connected to the fuel supply port, and the other ends of the plurality of tubes are connected to the fuel discharge port, and the non-porous layer is located more inward than the porous layer in the radial direction.[5] The fuel supply device according to [4], wherein the housing has a first passage extending from the fuel supply port into the housing and a second passage extending from the fuel outlet into the housing, the tube unit has a first bundling part bundling one ends of the plurality of tubes, a second bundling part bundling the other ends of the plurality of tubes, a first metal ring having a hole through which the first bundling part is passed, and a second metal ring having a hole through which the second bundling part is passed, at least a portion of the first bundling part extending into the first passage into which the first metal ring is fitted, and at least a portion of the second bundling part extending into the second passage into which the second metal ring is fitted. [6] The fuel supply device according to any of [1] to [5], wherein the plurality of layers further includes a second non-porous layer, and the porous layer is located between the non-porous layer and the second non-porous layer in the radial direction. [7] The fuel supply device according to any one of [1] to [6], further comprising a pressurizing mechanism that pressurizes the inside of the housing. [8] The fuel supply device according to any one of [1] to [7], wherein the gas is air, and further comprising a gas supply mechanism that supplies the gas into the housing while pressurizing it. [9] The fuel supply device according to any one of [1] to [8], wherein the housing is made of stainless steel, tin-galvanized steel, aluminum-plated steel, aluminum, or zinc-plated steel.

[0077] The fuel supply device according to the present disclosure has been described above. However, the fuel supply device according to the present disclosure is not limited to the above-described embodiments and modifications, and may be modified within the scope of the spirit of the claims. For example, the configuration of the combustion system according to the present disclosure, the shape, size, material, number, and arrangement of each part of the air intake device and tube unit may be modified as appropriate within the scope of the spirit of the present disclosure.

[0078] In the above embodiment and modified example, an example was described in which each end of the plurality of tubes 2 has a protrusion 2c. However, not all ends of the plurality of tubes 2 need to have a protrusion 2c, and at least some of the ends of the plurality of tubes may have a protrusion 2c. Even with this configuration, the ends of the plurality of tubes can be closely arranged, thereby improving the binding strength of the plurality of tubes.

[0079] In the above embodiment and modified example, the tubular portion 2b has been described as extending cylindrically along the extension direction of the tube 2. However, the tubular portion may have any shape as long as it extends cylindrically along the extension direction of the tube. The tubular shape of the tubular portion may be, for example, an oval, elliptical, or rectangular cylindrical shape. Even if the tubular portion is formed in this manner, if a protrusion protrudes from the tubular portion, the ends of multiple tubes can be closely arranged to improve the binding strength of the multiple tubes.

[0080] In the above embodiment and modified example, the tube unit 3 has been described as having a sealing portion 7. However, for example, in the case of a tube unit used in an air supply device other than the air supply device 103, the sealing portion 7 that seals between the ends of the multiple tubes 2 and the outer cylinder 6 may not be provided.

[0081] In the above embodiment and modified example, the housing body 11 has the protrusion 11f. However, for example, a protrusion with an opening may be provided on the cover 12 instead of the protrusion 11f.

[0082] 2, 2A, 2B...Tube, 2a...Internal space, 2b...Cylinder part, 2c...Protrusion part, 2d...Annular part, 3...Tube unit, 4...Casing, 4b...Space, 5...Bundling part, 5A...First bundling part , 5B...second binding part, 6...outer cylinder, 7...sealing part, 11...housing body, 11b...bottom part, 11c...side part, 11d...opening, 11f...protrusion part, 12...lid part, 12b...main body part, 12c...first Projection part, 12d...Second protrusion part, 13...First opening, 14...Second opening, 15a...Third opening, 16...First passage, 16b...First inner wall, 16c...Second inner wall, 16d...Third inner wall, 16f ... Inclined surface, 16h... Extension surface, 16x... Third inner wall, 17... Second passage, 17b... First inner wall, 17c... Second inner wall, 17d... Third inner wall, 17f... Inclined surface, 17h... Extension surface, 17x... Third 3 inner wall, 18b...first tube, 18c...second tube, 18d...third tube, 20...layer, 21...porous layer, 22, 22A...non-porous layers, 22B...second non-porous layer, 23A...first ferrule, 23b...tubular portion, 23B...second ferrule, 23c...inclined tubular portion, 24A...first metal ring, 24b...annular portion, 24B...second metal ring, 24c...tubular portion, 24d, 24f...holes , 25A...first pressure screw, 25B...second pressure screw, 26...tie band, 43...ferrule, 43b...tubular portion, 43c...inclined cylindrical portion, 44...metal ring, 44b...annular portion, 44c...inner surface, 100...combustion system, 101...fuel tank, 102...liquid delivery device, 103, 103A...air supply device, 104...gas supply device, 105...dissolved oxygen sensor, 106...combustion device.

Claims

1. A fuel supply device comprising: a housing having a fuel supply port for supplying liquid fuel, a gas supply port for supplying oxygen-containing gas, and a fuel discharge port for discharging the liquid fuel; and a tube unit housed in the housing and permeable to the gas, wherein each of a plurality of tubes included in the tube unit is made up of a plurality of layers aligned in the radial direction of the plurality of tubes, the plurality of layers including a porous layer and a non-porous layer that is permeable to the gas but not to the liquid fuel, and the non-porous layer is located between an area in the housing where the liquid fuel is housed and the porous layer.

2. The fuel supply device according to claim 1, wherein one ends of the plurality of tubes are connected to the gas supply port, and the non-porous layer is located outside the porous layer in the radial direction.

3. A fuel supply device as described in claim 2, wherein the housing has a first passage extending from the gas supply port to the inside of the housing, the tube unit has a first bundling part bundling one ends of the plurality of tubes and a first metal ring having a hole through which the first bundling part is passed, and at least a portion of the first bundling part extends into the first passage into which the first metal ring is fitted.

4. A fuel supply device as described in claim 1, wherein one ends of the plurality of tubes are connected to the fuel supply port, the other ends of the plurality of tubes are connected to the fuel discharge port, and the non-porous layer is located more inward than the porous layer in the radial direction.

5. A fuel supply device as described in claim 4, wherein the housing has a first passage extending from the fuel supply port into the housing and a second passage extending from the fuel discharge port into the housing, the tube unit has a first bundling part bundling one ends of the plurality of tubes, a second bundling part bundling the other ends of the plurality of tubes, a first metal ring having a hole through which the first bundling part is passed, and a second metal ring having a hole through which the second bundling part is passed, at least a portion of the first bundling part extending into the first passage in which the first metal ring is fitted, and at least a portion of the second bundling part extending into the second passage in which the second metal ring is fitted.

6. A fuel supply device according to any one of claims 1 to 5, wherein the plurality of layers further includes a second non-porous layer, and the porous layer is located between the non-porous layer and the second non-porous layer in the radial direction.

7. A fuel supply device according to any one of claims 1 to 6, further comprising a pressurizing mechanism for pressurizing the inside of the housing.

8. A fuel supply device according to any one of claims 1 to 6, wherein the gas is air, and further comprising a gas supply mechanism that supplies the gas into the housing while pressurizing it.

9. A fuel supply device according to any one of claims 1 to 8, wherein the housing is made of stainless steel, tin-galvanized steel, aluminum-plated steel, aluminum, or zinc-plated steel.

Images