Liquid hydrogen vaporizer

Abstract

To form a carburetor for liquid hydrogen in a compact form which can be mounted on a vehicle.SOLUTION: A carburetor 100 for liquid hydrogen conducts heat exchange between liquid hydrogen and helium gas and vaporizes the liquid hydrogen. The carburetor 100 includes: a lower first column tube 21 which is a fin tube comprising a tube 21A through which the liquid hydrogen flows, and a fin assembly 21D attached to an outer periphery of the tube 21A; and a lower casing 11 through which helium gas flows outside the lower first column tube 21. The fin assembly 21D comprises: a sleeve 21B covered on an outer surface of the tube 21A; and a plurality of fins 21C attached to an outer peripheral surface of the sleeve 21B. The sleeve 21B is slidable in a longitudinal direction of the tube 21A.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a structure of a liquid hydrogen vaporizer that vaporizes liquid hydrogen. [Background technology]

[0002] Patent Document 1 discloses a vaporizer that vaporizes liquid hydrogen by heat exchange between liquid hydrogen and helium gas. Patent Document 2 discloses a liquid hydrogen vaporization system that includes a vaporizer that vaporizes liquid hydrogen and a circulation flow path that circulates low-temperature helium gas flowing out of the vaporizer to the vaporizer. This liquid hydrogen vaporization system recovers cold energy generated during the vaporization of liquid hydrogen. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-21433 [Patent Document 2] JP 2015-158225 A Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, in recent years, fuel cell vehicles and hydrogen engine vehicles that use hydrogen gas are being put into practical use. These vehicles are equipped with hydrogen gas tanks, and hydrogen gas filled in the hydrogen gas tank is supplied to the fuel cell or hydrogen engine. There is a demand for these vehicles to have a longer cruising range. In order to increase the cruising range, it has been considered to mount a liquid hydrogen tank on the vehicle, vaporize liquid hydrogen in the vehicle to generate hydrogen gas, and supply the generated hydrogen gas to the fuel cell or hydrogen engine. However, there is a problem in that the vaporizers described in Patent Documents 1 and 2 are large and difficult to mount on the vehicle.

[0005] Therefore, an object of the present disclosure is to make a liquid hydrogen vaporizer compact enough to be mounted on a vehicle. [Means for solving the problem]

[0006] The liquid hydrogen vaporizer disclosed herein is a liquid hydrogen vaporizer that vaporizes liquid hydrogen by exchanging heat between liquid hydrogen and a heating medium, and is characterized in that it comprises a fin tube composed of a tube inside which liquid hydrogen flows and a fin assembly attached to the outer periphery of the tube, and a casing in which a heating medium flows on the outside of the fin tube contained inside, the fin assembly being composed of a sleeve that covers the outer surface of the tube and a plurality of fins attached to the outer periphery of the sleeve, and the sleeve being slidable in the longitudinal direction of the tube.

[0007] In this way, because the sleeve slides relative to the tube, the difference in thermal expansion between the sleeve and the tube can be absorbed, and thermal stress generated in the tube or sleeve can be suppressed. As a result, even if there is a temperature difference between the tube through which the cryogenic liquid hydrogen flows and the sleeve or fins in contact with the heating medium, the heat transfer area can be increased by the fins, and the liquid hydrogen vaporizer can be made compact enough to be mounted on a vehicle.

[0008] In the liquid hydrogen vaporizer of the present disclosure, the sleeve and the fins may be made of a material different from that of the tube.

[0009] For example, by constructing the tube in contact with liquid hydrogen from hydrogen-resistant stainless steel and the sleeve and fins from aluminum, which has a higher thermal conductivity than stainless steel, the heat exchange efficiency can be improved, and the liquid hydrogen vaporizer can be made more compact.

[0010] In the liquid hydrogen vaporizer of the present disclosure, the fin tube may be supported from the inner surface of the casing by the fins, with tips of the fins in contact with the inner surface of the casing.

[0011] As a result, the cryogenic tubes are not directly supported, so the support structure for the fin tubes can be simplified and the liquid hydrogen vaporizer can be made compact.

[0012] In the liquid hydrogen vaporizer of the present disclosure, the tube is composed of a single folded flow path in which an upward folded section, a first horizontal folded section, a downward folded section, and a second horizontal folded section are repeated in sequence with a straight pipe section in between, the fin assembly is provided on the straight pipe section, and each of the fins is a plurality of rectangular plates whose longitudinal direction extends radially from the outer circumferential surface of the sleeve and is attached to the sleeve so that their width direction is the extension direction of the sleeve, and the multiple fins may be arranged in a row with gaps between them along the extension direction of the sleeve.

[0013] This allows the fins to be arranged closely together, making the liquid hydrogen vaporizer compact. Also, since the tube is configured with a single folded flow path, there is no need to provide a header, making it possible to make the liquid hydrogen vaporizer compact.

[0014] In the liquid hydrogen vaporizer of the present disclosure, the heating medium may be helium gas.

[0015] Helium gas does not freeze and remains in a gaseous state even when it comes into contact with the outer surface of the tube, which is close to the temperature of liquid hydrogen. This prevents moisture from freezing on the surface of the tube and degrading the performance of the liquid hydrogen vaporizer, as occurs when air or other heating medium is used. Effect of the Invention

[0016] The present disclosure makes it possible to make a liquid hydrogen vaporizer compact enough to be mounted on a vehicle. [Brief description of the drawings]

[0017] [Figure 1] FIG. 2 is a perspective view of a liquid hydrogen vaporizer according to an embodiment. [Diagram 2]2A and 2B are a plan view and an elevational sectional view showing the tube arrangement of a lower heat exchanger of the liquid hydrogen vaporizer shown in FIG. [Diagram 3] 2A and 2B are a plan view and an elevational sectional view showing the tube arrangement of an upper heat exchanger of the liquid hydrogen vaporizer shown in FIG. 1. [Figure 4] FIG. 2 is a longitudinal cross-sectional view of a fin tube. [Diagram 5] FIG. 2 is a radial cross-sectional view of a fin tube. [Figure 6] 5A to 5C are explanatory diagrams showing a manufacturing method of a turn-back flow path. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] Hereinafter, the liquid hydrogen vaporizer 100 of the embodiment will be described with reference to the drawings. The arrows FR, UP, and RH shown in each drawing indicate the front, upper, and right sides of the liquid hydrogen vaporizer 100, respectively. The opposite directions of the arrows FR, UP, and RH indicate the rear, lower, and left sides. Hereinafter, when the directions of front, rear, left, right, and up and down are used in the description, they refer to the front and rear directions of the liquid hydrogen vaporizer 100, the left and right directions of the left and right directions, and the up and down directions of the up and down directions, unless otherwise specified. In addition, the liquid hydrogen vaporizer 100 is mounted on a vehicle so that the front side is the front of the vehicle (traveling direction), the upper side is the upper side of the vehicle, and the right side is the right side of the vehicle. Therefore, when the liquid hydrogen vaporizer 100 is mounted on a vehicle, the front side, upper side, and right side of the liquid hydrogen vaporizer 100 are the front side, upper side, and right side of the vehicle.

[0019] As shown in FIG. 1, the liquid hydrogen vaporizer 100 is composed of a lower heat exchanger 10 and an upper heat exchanger 30. The lower heat exchanger 10 is composed of a lower tube group 12 and a square box-shaped lower casing 11 that houses the lower tube group 12 inside. The upper heat exchanger 30 is composed of an upper tube group 32 and a square box-shaped upper casing 31 that houses the upper tube group 32. A liquid hydrogen inlet pipe 13 into which liquid hydrogen flows is connected to the right side of the lower tube group 12. In addition, the lower end of a tube group connection pipe 16 that connects the lower tube group 12 and the upper tube group 32 is connected to the left side of the lower tube group 12. The tube group connection pipe 16 extends in the vertical direction, and its upper end is connected to the left side of the upper tube group 32. A hydrogen gas outlet pipe 35 from which vaporized hydrogen gas flows out is connected to the right side of the upper tube group 32.

[0020] A helium gas inlet duct 51, into which helium gas, which is a heating medium, flows in, is connected to the right side of upper casing 31. An upper end of a helium gas connection duct 52, which connects upper casing 31 and lower casing 11, is connected to the left side of upper casing 31. A lower end of helium gas connection duct 52 is connected to the left side of lower casing 11. A helium gas outlet duct 53, through which helium gas flows out after heat exchange, is connected to the right side of lower casing 11.

[0021] Liquid hydrogen that flows into the right side of the lower tube group 12 from the liquid hydrogen inlet pipe 13 flows to the left through the lower tube group 12 and becomes a two-layer flow of liquid hydrogen and hydrogen gas before flowing out to the tube group connecting pipe 16. The liquid hydrogen and hydrogen gas pass through the tube group connecting pipe 16 and flow into the left side of the upper tube group 32. The liquid hydrogen and hydrogen gas that flow into the upper tube group 32 flow to the right through the upper tube group 32 and become hydrogen gas before flowing out of the hydrogen gas outlet pipe 35 on the right side.

[0022] Helium gas that flows into the right side of upper casing 31 from helium gas inlet duct 51 flows to the left inside upper casing 31 and flows into the left side of lower casing 11 through helium gas connection duct 52. Helium gas that flows into lower casing 11 flows to the right inside lower casing 11 and flows out from the right side of lower casing 11.

[0023] Thus, in the lower heat exchange section 10, liquid hydrogen flows from right to left, and helium gas flows from left to right. In the upper heat exchange section 30, liquid hydrogen and hydrogen gas flow from left to right, and helium gas flows from right to left. Therefore, the liquid hydrogen vaporizer 100 is an opposed-type heat exchanger in which the hydrogen and helium gas flow in opposite directions.

[0024] Next, the detailed structure of the lower tube group 12 will be described with reference to FIG. 2. The upper diagram of FIG. 2 is a plan view of the lower heat exchanger 10, and the lower diagram is a cross section of AA shown in the upper diagram. In the upper diagram of FIG. 2, the dashed lines indicate the lower fin tube, U-bend, and piping, and the solid lines indicate the upper fin tube, U-bend, and piping. The arrows in the diagram indicate the direction of flow of liquid hydrogen, and the hollow arrows indicate the direction of flow of helium gas. The figure with a black circle in the center of the circle in the diagram indicates that liquid hydrogen or hydrogen gas in the fin tube flows toward the front side of the paper (from the front to the rear of the vaporizer 100). The figure with an X mark in the circle in the diagram indicates that liquid hydrogen or hydrogen gas in the fin tube flows toward the back side of the paper (from the rear to the front of the vaporizer 100).

[0025] First, the tube arrangement of the lower tube group 12 will be described. The lower tube group 12 is composed of a lower first turn-back flow path block 20A, a lower second turn-back flow path block 20B, a lower third turn-back flow path block 20C, and a lower fourth turn-back flow path block 20D, which are arranged side by side from right to left. The lower first turn-back flow path block 20A is composed of a lower first row tube 21, a lower second row tube 27, an upper first row tube 23, an upper second row tube 25, first and second vertical U-bends 22, 26, and first and second horizontal U-bends 24, 28. The lower first row tube 21, the upper first row tube 23, the lower second row tube 27, and the upper second row tube 25 are straight tube sections composed of straight fin tubes extending in the front-rear direction, and are arranged in parallel with each other at a pitch P in the left-right direction. In addition, in FIG. 2, the sleeve 21B and the fins 21C (see FIGS. 4 and 5) are omitted.

[0026] The lower first row tube 21 and the lower second row tube 27 are straight fin tubes extending in the front-rear direction below the lower tube group 12. The lower first row tube 21 and the lower second row tube 27 are arranged parallel to each other at a pitch of 2P in the left-right direction. The upper first row tube 23 and the upper second row tube 25 are fin tubes arranged above the lower first row tube 21 and the lower second row tube 27 and extending in the front-rear direction. The upper first row tube 23 and the upper second row tube 25 are arranged parallel to each other at a pitch of 2P in the left-right direction at positions shifted leftward from the lower first row tube 21 and the lower second row tube 27 by the pitch P.

[0027] The first vertical U-bend 22 is a U-shaped tube that vertically connects the rear end of the lower first row tube 21 to the rear end of the upper first row tube 23. The second vertical U-bend 26 is a U-shaped tube that vertically connects the rear end of the upper second row tube 25 to the rear end of the lower second row tube 27. The first horizontal U-bend 24 is a U-shaped tube that horizontally connects the front end of the upper first row tube 23 to the front end of the upper second row tube 25. The second horizontal U-bend 28 is a U-shaped tube that horizontally connects the lower second row tube 27 to the lower third row tube 29.

[0028] An elbow 14 is connected to the front end side of the lower first row pipe 21, and a liquid hydrogen inlet pipe 13 is connected to the elbow 14.

[0029] Liquid hydrogen flowing in from the liquid hydrogen inlet pipe 13 flows backward through the lower first row pipe 21 and into the first vertical U-bend 22, as shown by the arrow in the figure. The liquid hydrogen flowing in the first vertical U-bend 22 flows upwardly at the first vertical U-bend 22 and into the upper first row pipe 23. The liquid hydrogen flowing in the upper first row pipe 23 flows forward through the upper first row pipe 23 and into the first horizontal U-bend 24. The liquid hydrogen flowing in the first horizontal U-bend 24 flows horizontally at the first horizontal U-bend 24 and into the upper second row pipe 25. The liquid hydrogen flowing in the upper second row pipe 25 flows backward and into the second vertical U-bend 26. The liquid hydrogen flowing in the second vertical U-bend 26 flows downwardly at the second vertical U-bend 26 and into the lower second row pipe 27. The liquid hydrogen that flows into the lower second row pipes 27 flows forward through the lower second row pipes 27 and flows into the second horizontal U-bend 28. The liquid hydrogen that flows into the second horizontal U-bend 28 flows in a manner such that it is turned back laterally at the second horizontal U-bend 28 and flows into the lower third row pipes 29.

[0030] In this way, the first vertical U-bend 22 constitutes an upward turn portion that turns the flow of liquid hydrogen upward, the second vertical U-bend 26 constitutes a downward turn portion that turns the flow of liquid hydrogen downward, and the first horizontal U-bend 24 and the second horizontal U-bend 28 constitute a first horizontal turn portion and a second horizontal turn portion that turn the flow of liquid hydrogen horizontally.

[0031] In this manner, the lower first turn flow path block 20A is a turn flow path in which the first vertical U-bend 22, the first horizontal U-bend 24, the second vertical U-bend 26, and the second horizontal U-bend 28 are connected with the upper first row tube 23, the upper second row tube 25, and the lower second row tube 27 sandwiched between them, and the lower first row tube 21 is connected below the first vertical U-bend 22.

[0032] The lower second turn flow path block 20B to the lower fourth turn flow path block 20D have the same structure as the lower first turn flow path block 20A. The lower first to lower third turn flow path blocks 20A to 20C are connected to the lower left straight pipe section and the lower right straight pipe section of the lower second to lower fourth turn flow path blocks 20B to 20D by horizontal U-bends. As a result, the lower first turn flow path block 20A to the lower fourth turn flow path block 20D constitute a lower pipe group 12 consisting of a single turn flow path.

[0033] An elbow 15 is connected to the straight pipe at the lower left of the lower fourth turn flow path block 20D, and a tube group connecting pipe 16 is connected to the elbow 15. The tube group connecting pipe 16 is connected to the upper tube group 32.

[0034] Next, the configuration of the upper tube group 32 will be described with reference to Fig. 3. Portions similar to the configuration of the lower tube group 12 described above will be briefly described. As in Fig. 2, the upper view of Fig. 3 is a plan view of the upper heat exchange section 30, and the lower view is a cross section of BB shown in the upper view. In the upper view of Fig. 3, the dashed lines indicate the lower fin tubes, U-bends, and piping, and the solid lines indicate the upper fin tubes, U-bends, and piping. In the drawing, the arrows indicate the flow direction of the two-layer flow of liquid hydrogen and hydrogen gas, and the hollow arrows indicate the flow direction of helium gas.

[0035] The upper tube group 32 is composed of an upper first turn-back flow path block 40A, an upper second turn-back flow path block 40B, an upper third turn-back flow path block 40C, and an upper fourth turn-back flow path block 40D, which are arranged and connected from left to right. The upper first turn-back flow path block 40A is composed of an upper first row tube 41, an upper second row tube 47, a lower first row tube 43, a lower second row tube 45, first and second vertical U-bends 42, 46, and first and second horizontal U-bends 44, 48. The upper first row tube 41, the lower first row tube 43, the upper second row tube 47, and the lower second row tube 45 are straight tube sections composed of straight fin tubes extending in the front-rear direction, and are arranged in parallel with each other at a pitch P in the left-right direction.

[0036] The first vertical U-bend 42 vertically connects the upper first row tube 41 and the lower first row tube 43, and constitutes a downward turn-back portion. The second vertical U-bend 46 vertically connects the lower second row tube 45 and the upper second row tube 47, and constitutes an upward turn-back portion. The first horizontal U-bend 44 horizontally connects the lower first row tube 43 and the lower second row tube 45, and constitutes a first horizontal turn-back portion. The second horizontal U-bend 48 horizontally connects the upper second row tube 47 and the upper third row tube 49, and constitutes a second horizontal turn-back portion.

[0037] In this way, the upper first turn flow path block 40A forms a turn flow path in which the first vertical U-bend 42, the first horizontal U-bend 44, the second vertical U-bend 26, and the second horizontal U-bend 28 are connected with the lower first row tube 43, the lower second row tube 45, and the upper second row tube 47 in between, and the upper first row tube 41 is connected to the upper side of the first vertical U-bend 42.

[0038] The upper second turn flow path block 40B to the upper fourth turn flow path block 40D have the same structure as the upper first turn flow path block 40A. The upper right straight pipe section of each of the upper first to upper third turn flow path blocks 40A to 40C is connected to the upper left straight pipe section of each of the upper second to upper fourth turn flow path blocks 40B to 40D by a horizontal U-bend. As a result, the upper first turn flow path block 40A to the upper fourth turn flow path block 40D constitute the upper tube group 32 composed of a single turn flow path.

[0039] The lower tube group 12 and the upper tube group 32 are connected by a single tube group connecting pipe 16. Therefore, the lower tube group 12 and the upper tube group 32 are configured as a single turn-back flow path as a whole. This eliminates the need for a header, making the configuration simple and compact.

[0040] Next, the configuration of the fin tube will be described with reference to Figs. 4 and 5. As shown in Fig. 4, the lower first row tube 21, which is a fin tube, is composed of a tube 21A and a fin assembly 21D. The fin assembly 21D is composed of a sleeve 21B and a fin 21C attached to the sleeve 21B. Liquid hydrogen or hydrogen gas flows inside the cylindrical tube 21A. The tube 21A is composed of a material such as stainless steel that is resistant to hydrogen. The sleeve 21B is a cylindrical member that is placed on the outer circumferential surface of the cylindrical tube 21A. The sleeve 21B is fitted on the outer circumferential surface of the tube 21A so as to be movable in the longitudinal direction relative to the tube 21A. Each fin 21C is composed of a rectangular plate. Each fin 21C is attached to the outer circumferential surface of the sleeve 21B so that the longitudinal direction extends radially from the outer circumferential surface of the sleeve 21B and the width direction is the extension direction of the sleeve 21B. The multiple fins 21C are arranged in a row along the direction of the sleeve 21B with gaps S between them. The sleeve 21B and the fins 21C are made of a material with a higher thermal conductivity than the material of the tube 21A. When the tube 21A is made of stainless steel, the sleeve 21B and the fins 21C may be made of, for example, aluminum or the like that has a higher thermal conductivity than stainless steel.

[0041] Here, the detailed configuration of the lower first turn-back flow path block 20A will be described with reference to FIG. 5. As shown in FIG. 5, the fins 21C of the lower first row tube 21 of the lower first turn-back flow path block 20A extend radially in four directions, namely, upward, downward, diagonally upward, and diagonally downward. Like the lower first row tube 21, the lower second row tube 27, the upper first row tube 23, and the upper second row tube 25 are each composed of tubes 27A, 23A, and 25A, and fin assemblies 27D, 23D, and 25D. The fin assemblies 27D, 23D, and 25D are each composed of sleeves 23B, 25B, and 28B, and fins 27C, 23C, and 25C. The fins 27C, 23C, and 25C are attached to the sleeves 23B, 25B, and 27B so as to extend radially in four directions. As shown by the white arrows in Fig. 5, the helium gas flows through the gaps S (see Fig. 4) between each of the fins 21C, 23C, 25C, and 27C, which are rectangular plates arranged in a row in the longitudinal direction, and exchanges heat with the liquid hydrogen flowing through the tubes 21A, 23A, 25A, and 27A. When the helium gas passes through the gaps S, it becomes turbulent and flows over the surfaces of each of the fins 21C, 23C, 25C, and 27C, increasing the heat transfer coefficient between each of the fins 21C, 23C, 25C, and 27C and the helium gas. This improves the efficiency of heat exchange between the liquid hydrogen and the helium gas.

[0042] The lower ends 21E of the lower fins 21C of the lower first row tube 21 and the lower ends 27E of the lower fins 27C of the lower second row tube 27 are in contact with the inner surface 11A of the lower casing 11. As a result, the lower first turn-back flow path block 20A is supported from the inner surface 11A of the lower casing 11 by the fins 21C.

[0043] The detailed configuration of each fin tube and the arrangement of the fins included in the lower second turn-back flow path block 20B to the lower fourth turn-back flow path block 20D are similar to those of the lower first turn-back flow path block 20A. The lower ends of the fins of the fin tubes arranged on the lower sides of the lower second turn-back flow path block 20B to the lower fourth turn-back flow path block 20D are in contact with the inner surface 11A of the lower casing 11. As a result, the lower second turn-back flow path block 20B to the lower fourth turn-back flow path block 20D are supported from the inner surface 11A of the lower casing 11 by the fins of the fin tubes.

[0044] The detailed configuration of each fin tube and the arrangement of the fins included in the upper first turn-back flow path block 40A to the upper fourth turn-back flow path block 40D are similar to those of the lower first turn-back flow path block 20A described above. The lower ends of the fin tubes arranged on the lower sides of the upper first turn-back flow path block 40A to the upper fourth turn-back flow path block 40D are in contact with the inner surface 31A (see FIG. 3) of the upper casing 31. As a result, the upper first turn-back flow path block 40A to the upper fourth turn-back flow path block 40D are supported from the inner surface 31A of the upper casing 31 by the fins of the fin tubes.

[0045] Next, referring to FIG. 6, an example of a manufacturing method of a turn-back flow path in which a fin tube and a U-bend are connected will be briefly described. In the following, a part of the manufacturing process of the lower first turn-back flow path block 20A will be described. As shown in the upper diagram of FIG. 6, a long straight tube 70 made of stainless steel or the like is prepared. In addition, a fin assembly 71D in which a fin 71C is attached to a sleeve 71B and a fin assembly 73D in which a fin 73C is attached to a sleeve 73B are prepared. The length of each fin assembly 71D, 73D is approximately the same as the length of the lower first row tube 21 and the upper first row tube 23.

[0046] Next, fin assembly 71D is fitted onto the outer periphery of fin tube component 71 of tube 70. Similarly, fin assembly 73D is fitted onto the outer periphery of fin tube component 73 of tube 70.

[0047] Then, the U-bend component 72 between the fin tube components 71, 73 is bent into a U shape. As a result, the fin tube component 71 becomes the lower first row tube 21 composed of the tube 21A and the fin assembly 21D. Moreover, the fin tube component 73 becomes the upper first row tube 23 composed of the tube 23A and the fin assembly 23D. The U-bend component 72 becomes the first vertical U-bend 22. This manufacturing method makes it possible to form a turn-back flow path in a simple manner without welding the tube and the U-bend.

[0048] The manufacturing method is not limited to the above, and the fin tubes constituting the lower first row pipe 21, the fin tubes constituting the upper first row pipe 23, and the first vertical U-bend 22 may be manufactured separately and then connected by welding or the like.

[0049] In the liquid hydrogen vaporizer 100 described above, the sleeve 21B slides relative to the tube 21A, absorbing the difference in thermal expansion between the sleeve 21B and the tube 21A and suppressing the thermal stress generated in the tube 21A or the sleeve 21B. This allows the liquid hydrogen vaporizer 100 to increase the heat transfer area by the fins 21C even if there is a temperature difference between the tube 21A through which the cryogenic liquid hydrogen flows and the sleeve 21B or the fins 21C which are in contact with the helium gas. This allows the liquid hydrogen vaporizer 100 to be made compact enough to be mounted on a vehicle.

[0050] Furthermore, by constructing sleeve 21B and fins 21C from aluminum or the like, which has a higher thermal conductivity than the stainless steel that constitutes tube 21A, liquid hydrogen vaporizer 100 can have an improved heat exchange efficiency, thereby making liquid hydrogen vaporizer 100 more compact.

[0051] Furthermore, in the liquid hydrogen vaporizer 100, the lower tube group 12 and the upper tube group 32 are entirely configured as a single return flow path, so there is no need to provide a header, making the configuration simple and compact.

[0052] In addition, in the liquid hydrogen vaporizer 100, the fins 27C, 23C, and 25C are attached to the sleeves 23B, 25B, and 27B so as to extend radially in four directions. This allows a large number of rectangular plate fins 21C, 23C, 25C, and 27C to be densely arranged, resulting in a compact configuration. In addition, the turbulence generated when the helium gas passes through the gaps S (see FIG. 4) between the fins 21C, 23C, 25C, and 27C increases the heat transfer coefficient between the fins 21C, 23C, 25C, and 27C and the helium gas, thereby improving the heat exchange efficiency between the liquid hydrogen and the helium gas. This allows the liquid hydrogen vaporizer 100 to be made compact.

[0053] Furthermore, the lower first turn-back flow path block 20A to the lower fourth turn-back flow path block 20D of the liquid hydrogen vaporizer 100 are supported from the inner surface 11A of the lower casing 11 by the fins of the fin tubes. Similarly, the upper first turn-back flow path block 40A to the upper fourth turn-back flow path block 40D are supported from the inner surface 31A of the upper casing 31 by the fins of the fin tubes. This makes it unnecessary to support each tube inside which cryogenic liquid hydrogen flows and whose outer surface has a cryogenic temperature, thereby simplifying the structure.

[0054] Furthermore, liquid hydrogen vaporizer 100 uses helium gas as the heating medium, which remains in a gaseous state without freezing even when it touches the outer surface of the tube, which is close to the temperature of liquid hydrogen, so this prevents moisture from freezing on the surface of the tube and causing a decrease in performance of liquid hydrogen vaporizer 100, as occurs when air or other heating medium is used. [Explanation of symbols]

[0055] 10 lower heat exchange section, 11 lower casing, 11A, 31A inner surface, 12 lower tube group, 13 liquid hydrogen inlet pipe, 14, 15 elbow, 16 tube group connecting pipe, 20A lower first turn flow path block, 20B lower second turn flow path block, 20C lower third turn flow path block, 20D lower fourth turn flow path block, 21 lower first row tube, 21A, 23A, 25A, 27A, 70 tube, 21B, 23B, 25B, 27B, 71B, 73B sleeve, 21C, 23C, 25C, 27C, 71C, 73C fin, 21D, 23D, 25D, 27D, 71D, 73D fin assembly, 21E, 27E lower end, 22, 42 first vertical U-bend, 23 Upper first row tube, 24, 44 First horizontal U-bend, 25 Upper second row tube, 26, 46 Second vertical U-bend, 27 Lower second row tube, 28, 48 Second horizontal U-bend, 29 Lower third row tube, 30 Upper heat exchange section, 31 Upper casing, 32 Upper tube group, 35 Hydrogen gas outlet tube, 40A Upper first turn-back flow path block, 40B Upper second turn-back flow path block, 40C Upper third turn-back flow path block, 40D Upper fourth turn-back flow path block, 41 Upper first row tube, 43 Lower first row tube, 45 Lower second row tube, 47 Upper second row tube, 49 Upper third row tube, 51 Helium gas inlet duct, 52 Helium gas connection duct, 53 Helium gas outlet duct, 71, 73 Fin tube component, 72 U-bend component, 100 Vaporizer for liquid hydrogen.

Claims

1. A liquid hydrogen vaporizer that vaporizes liquid hydrogen by performing heat exchange between liquid hydrogen and a heating medium, A fin tube including a tube through which liquid hydrogen flows and a fin assembly attached to the outer periphery of the tube; A casing in which a heating medium flows outside the fin tubes housed therein, The fin assembly includes: A sleeve that covers the outer surface of the tube; a plurality of fins attached to an outer peripheral surface of the sleeve; The sleeve is slidable in the longitudinal direction of the tube; A liquid hydrogen vaporizer characterized by:

2. 2. The liquid hydrogen vaporizer according to claim 1, the sleeve and the fin are made of a material different from that of the tube; A liquid hydrogen vaporizer characterized by:

3. 3. The liquid hydrogen vaporizer according to claim 1, the fin tube has a tip of a fin in contact with an inner surface of the casing and is supported from the inner surface of the casing by the fin; A liquid hydrogen vaporizer characterized by:

4. 3. The liquid hydrogen vaporizer according to claim 1, The tube is configured as a single folded flow path in which an upward folded portion, a first horizontal folded portion, a downward folded portion, and a second horizontal folded portion are repeated in sequence with a straight pipe portion sandwiched therebetween, The fin assembly is provided on the straight pipe portion, Each of the fins is a plurality of rectangular plates whose longitudinal direction extends in a radial direction from the outer circumferential surface of the sleeve, and is attached to the sleeve such that its width direction is the extension direction of the sleeve, The fins are arranged in a row with gaps between them along the extension direction of the sleeve; A liquid hydrogen vaporizer characterized by:

5. 3. The liquid hydrogen vaporizer according to claim 1, The heating medium is helium gas. A liquid hydrogen vaporizer characterized by:

Images