Hydrogen tank structure

Abstract

To provide a hydrogen tank structure capable of suppressing heat transfer from a manifold to a hydrogen gas flow path, and preventing temperature rise of filled hydrogen gas.SOLUTION: A hydrogen tank structure 1 comprises a plurality of hydrogen tanks 2 arranged in parallel, and a long manifold 3 connected to one end part of each hydrogen tank 2. The manifold 3 extends along a longitudinal direction of the manifold 3 inside the manifold 3, and has a hydrogen gas flow path 32 that communicates with the inside of each hydrogen tank 2, and a heat insulation part 33 provided near the hydrogen gas flow path 32.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a hydrogen tank structure. [Background technology]

[0002] Conventionally, such a technical field is exemplified by that described in Patent Document 1. The hydrogen tank structure described in Patent Document 1 includes multiple small hydrogen tanks arranged in parallel and a manifold for fixing the hydrogen tanks and filling each tank with hydrogen gas. A hydrogen gas flow path is provided inside the manifold, and cooled hydrogen gas is filled into each hydrogen tank via the hydrogen gas flow path. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-32034 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the above-mentioned hydrogen tank structure, the manifold is made of metal and has a large thermal mass (i.e., heat capacity), so when the cooled hydrogen gas passes through the hydrogen gas flow path inside the manifold, it receives heat from the manifold and its temperature rises. When the temperature rises, the amount of hydrogen filled into the tank decreases, resulting in the problem that the tank is not filled to capacity. To solve this problem, consideration has been given to reducing the size of the manifold to reduce the thermal mass, but this creates a new problem of reducing the drop resistance of the manifold.

[0005] The present invention has been made to solve such technical problems, and aims to provide a hydrogen tank structure that can suppress heat transfer from the manifold to the hydrogen gas flow path and prevent the temperature of the filled hydrogen gas from rising. [Means for solving the problem]

[0006] The hydrogen tank structure of the present invention is a hydrogen tank structure comprising a plurality of hydrogen tanks arranged in parallel and a long manifold connected to one end of each hydrogen tank, wherein the manifold extends along the longitudinal direction of the manifold inside the manifold and has a hydrogen gas flow path communicating with the interior of each hydrogen tank, and an insulating section provided in the vicinity of the hydrogen gas flow path.

[0007] In the hydrogen tank structure according to the present invention, the heat insulating portion provided near the hydrogen gas flow path serves to suppress heat transfer from the manifold to the hydrogen gas flow path, and can suppress a rise in temperature of the hydrogen gas flowing through the hydrogen gas flow path. As a result, heat received from the manifold during hydrogen gas filling can be reduced, and a rise in temperature of the filled hydrogen gas can be prevented. As a result, a decrease in the amount of hydrogen filled due to a rise in temperature can be suppressed.

[0008] In the hydrogen tank structure according to the present invention, the insulating section is a hollow section provided inside the manifold and extending along the longitudinal direction of the manifold, and when viewed from the longitudinal direction of the manifold, the hollow section is preferably formed in a C-shaped cross section so as to surround the hydrogen gas flow path, with the opening of the C facing the hydrogen tank. In this way, the insulating section suppresses heat transfer from the manifold to the hydrogen gas flow path, thereby reducing heat reception from the manifold and preventing a rise in temperature of the filled hydrogen gas.

[0009] In the hydrogen tank structure according to the present invention, it is preferable that the manifold further includes a manifold body in which the hydrogen gas flow path is provided, and the heat insulating portion is a heat insulating material arranged on the outer periphery of the manifold body so as to surround the manifold body. In this case, the heat insulating material arranged on the outer periphery of the manifold body is used to block heat transfer from the external environment to the manifold body, thereby reducing the effect of the outside air temperature on the manifold body. As a result, heat transfer from the manifold to the hydrogen gas flow path is suppressed, and a rise in temperature of the filled hydrogen gas can be prevented.

[0010] In the hydrogen tank structure according to the present invention, the heat insulating portion is preferably a heat insulating coating provided on the inner wall surface of the hydrogen gas flow path. In this case, the heat insulating coating can be used to suppress heat transfer from the manifold to the hydrogen gas flow path, thereby preventing a rise in temperature of the filled hydrogen gas.

[0011] In the hydrogen tank structure according to the present invention, it is preferable that the insulating portion is a gas circulation path that communicates with the hydrogen gas flow path and circulates hydrogen gas inside the manifold. In this case, by utilizing the gas circulation path, it is possible to suppress heat transfer from the manifold to the hydrogen gas flow path, thereby preventing a rise in temperature of the filled hydrogen gas and suppressing unevenness in temperature of the filled hydrogen gas. Effect of the Invention

[0012] According to the present invention, it is possible to suppress the heat transfer from the manifold to the hydrogen gas flow passage, and to prevent the temperature rise of the filled hydrogen gas. [Brief description of the drawings]

[0013] [Figure 1] 1 is a schematic cross-sectional view showing a hydrogen tank structure according to a first embodiment. [Diagram 2] 2 is a cross-sectional view taken along lines AA and BB in FIG. 1. [Diagram 3] FIG. 6 is a cross-sectional view showing a hydrogen tank structure according to a second embodiment. [Figure 4]FIG. 11 is a cross-sectional view showing a hydrogen tank structure according to a third embodiment. [Diagram 5] FIG. 11 is a schematic cross-sectional view showing a hydrogen tank structure according to a fourth embodiment. [Figure 6] 6 is a cross-sectional view taken along lines CC and DD in FIG. 5. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Hereinafter, an embodiment of a tank holding structure according to the present invention will be described with reference to the drawings. In the description of the drawings, the same elements are given the same reference numerals and duplicated description will be omitted.

[0015] [First embodiment] Fig. 1 is a schematic cross-sectional view showing the hydrogen tank structure according to the first embodiment, and Fig. 2 is a cross-sectional view taken along lines AA and BB in Fig. 1. Note that in Fig. 1, in order to make it easier to understand the structure of a receiving recess 34 (described later) of a manifold 3, the hydrogen tank 2 is shown in a state before being inserted into the receiving recess 34.

[0016] The hydrogen tank structure 1 of this embodiment is installed, for example, in a fuel cell vehicle (not shown), and comprises a plurality of hydrogen tanks 2 arranged in parallel and a long manifold 3 connected to one end of each hydrogen tank 2.

[0017] The hydrogen tank 2, also called a chamber, is a small-diameter tank with a small mouth, and is a high-pressure container having a space for storing hydrogen gas inside. This hydrogen tank 2 has a substantially cylindrical tank body 21 and a nozzle part 22 attached to the open end of the tank body 21. Although not shown, the tank body 21 has a substantially cylindrical liner with both ends rounded like a dome, and a fiber-reinforced resin layer covering the outer circumferential surface of the liner. The liner may be made of aluminum or resin.

[0018] The nozzle part 22 is made of a metal material such as stainless steel or an aluminum alloy and machined into a cylindrical shape, and has a cylindrical nozzle body 23 extending along the axial direction of the hydrogen tank 2, and a flange part 24 connected to one end of the nozzle body 23 and protruding in the radial direction. The nozzle part 22 is fitted onto the open end of the tank body 21 and fixed to the open end by screwing.

[0019] Further, a male thread portion 231 that screws into a female thread portion 341 formed in the receiving recess 34 of the manifold 3 is formed on the outer peripheral wall of the base body 23. The flange portion 24 serves to increase the strength of the base portion 22 as a whole and to regulate the screwing depth when screwing into the manifold 3. The flange portion 24 is formed integrally with the base body 23.

[0020] A plurality of hydrogen tanks 2 having such a structure are arranged side by side in one direction, as shown in Figure 1. Each hydrogen tank 2 is inserted into a receiving recess 34 of the manifold 3, and is connected to the manifold 3 by screwing the male thread portion 231 into the female thread portion 341 of the receiving recess 34.

[0021] The manifold 3 is a metal member that serves to fix the multiple hydrogen tanks 2 and to fill hydrogen gas into each hydrogen tank 2. In this embodiment, the manifold 3 is formed from, for example, an aluminum extrusion material.

[0022] The manifold 3 has an elongated manifold body 31 having a rectangular cross section, a hydrogen gas flow path 32 provided inside the manifold body 31 , and a heat insulating section 33 provided in the vicinity of the hydrogen gas flow path 32 .

[0023] The manifold body 31 is provided with a plurality of receiving recesses 34 for receiving the nozzle portion 22 of the hydrogen tank 2. As shown in Fig. 1, these multiple receiving recesses 34 are arranged at equal intervals along the longitudinal direction of the manifold body 31 and are located on the same side (the hydrogen tank 2 side) of the manifold body 31. The receiving recesses 34 are formed as cylindrical cavities and open towards the hydrogen tank 2. A female thread portion 341 for screwing together with the male thread portion 231 of the nozzle portion 22 of the hydrogen tank 2 is formed on the inner circumferential wall of the receiving recess 34.

[0024] The hydrogen gas flow path 32 is disposed at approximately the center of the manifold body 31 and has a main flow path 321 extending along the longitudinal direction of the manifold body 31, and a plurality of sub-flow paths 322 branching off from the main flow path 321 and communicating the main flow path 321 with the receiving recess 34. The main flow path 321 has a circular cross section, one end in the longitudinal direction of the main flow path 321 is connected to the In / Out connect 4, and the other end is blocked by an end plug 5. The sub-flow paths 322 are provided in a one-to-one correspondence with the plurality of receiving recesses 34. The sub-flow paths 322 are arranged coaxially with the opening of the tank body 21 inserted into the receiving recess 34.

[0025] The hydrogen gas flow path 32 is connected to a valve (not shown) attached to the manifold 3 via the In / Out connect 4. When filling with hydrogen, hydrogen gas supplied from the hydrogen station flows in a cooled state (for example, at −40° C.) through the valve and the In / Out connect 4 into the main flow path 321, and further flows into the inside of the hydrogen tank 2 via the sub-flow path 322.

[0026] The heat insulating section 33 is composed of a hollow portion extending along the longitudinal direction of the manifold body 31 inside the manifold body 31. As shown in Fig. 2, when viewed from the longitudinal direction of the manifold body 31, the heat insulating section 33 (i.e., the hollow portion) is formed with a C-shaped cross section so as to surround the hydrogen gas flow path 32, with the opening of the C facing the hydrogen tank 2 side.

[0027] 1, one longitudinal end of the heat insulating section 33 is blocked by an In / Out connect 4, and the other end is blocked by an end plug 5. The heat insulating section 33 on the In / Out connect 4 side communicates with the hydrogen gas flow path 32 via a communication passage 6. During hydrogen filling, hydrogen gas also flows into the inside of the heat insulating section 33 (i.e., the hollow portion) via the communication passage 6, but no flow of hydrogen gas occurs because the other end of the heat insulating section 33 is blocked by the end plug 5.

[0028] 2, the main flow passage 321 of the hydrogen gas flow passage 32 is disposed inside the heat insulating portion 33 having a C-shaped cross section. On the other hand, the sub-flow passage 322 of the hydrogen gas flow passage 32 passes through an opening of the C-shaped heat insulating portion 33 and communicates between the main flow passage 321 and the receiving recess 34.

[0029] In the hydrogen tank structure 1 according to this embodiment, the heat insulating section 33 communicates with the hydrogen gas flow passage 32 through the communication passage 6, so that the pressure of the heat insulating section 33 and the pressure of the hydrogen gas flow passage 32 are the same. In addition, the heat insulating section 33 has a C-shaped cross section and surrounds the main flow passage 321 of the hydrogen gas flow passage 32, so that the heat transfer from the manifold 3 to the main flow passage 321 of the hydrogen gas flow passage 32 is suppressed, and the heat reception from the manifold 3 can be reduced. Therefore, when hydrogen is filled, the temperature rise of the filled hydrogen gas can be prevented, and the decrease in the amount of hydrogen filled due to the temperature rise can be suppressed. Furthermore, by doing so, it is not necessary to reduce the size of the manifold 3, so that the drop resistance of the manifold 3 is not affected. As a result, the heat reception from the manifold 3 can be reduced without deteriorating the drop resistance.

[0030] [Second embodiment] A second embodiment of the hydrogen tank structure will be described below with reference to Fig. 3. The hydrogen tank structure 1A of this embodiment differs from the first embodiment described above in the structure of the heat insulating portion. The other structures are the same as those of the first embodiment, so duplicated explanations will be omitted.

[0031] 3, the heat insulating portion 33A in this embodiment is a heat insulating material arranged on the outer periphery of the manifold body 31 so as to surround the manifold body 31. More specifically, the heat insulating portion 33A is formed in a square tube shape by wrapping a sheet-like heat insulating material around the outer periphery of the manifold body 31. The heat insulating material is adhered to the outer periphery of the manifold body 31 with, for example, an adhesive. Note that the heat insulating portion 33A is not provided where the receiving recess 34 is formed so as not to interfere with the insertion of the hydrogen tank 2.

[0032] The heat insulating material may be, for example, a synthetic resin foam or a fiber heat insulating material. As the synthetic resin foam, foams having closed cells such as polyethylene, polypropylene, polystyrene, polyurethane, and phenolic resin can be used. As the fiber heat insulating material, glass fiber, polyester or nylon nonwoven fabric, cellulose fiber, etc. can be used.

[0033] According to the hydrogen tank structure 1A of this embodiment, the influence of the outside air temperature on the manifold body 31 can be reduced by blocking the transfer of heat from the external environment to the manifold body 31 using a heat insulating material arranged on the outer periphery of the manifold body 31. This suppresses the transfer of heat from the manifold 3 to the hydrogen gas flow path 32, and reduces the amount of heat received from the manifold 3. Therefore, when hydrogen is filled, a rise in the temperature of the filled hydrogen gas can be prevented, and a decrease in the amount of hydrogen filled due to the temperature rise can be suppressed. Furthermore, since the heat insulating material is arranged on the outer periphery of the manifold body 31 so as to surround the manifold body 31, it can also perform a buffering function to protect the manifold body 31, and the drop resistance of the manifold 3 can be improved.

[0034] [Third embodiment] Hereinafter, a third embodiment of the hydrogen tank structure will be described with reference to Fig. 4. The hydrogen tank structure 1B of this embodiment differs from the first embodiment described above in the structure of the heat insulating portion. The other structures are the same as those of the first embodiment, so duplicated explanations will be omitted.

[0035] 4, the heat insulating portion 33B of this embodiment is a heat insulating coating provided on the inner wall surface of the hydrogen gas flow path 32. More specifically, a heat insulating coating having a lower thermal conductivity than the manifold body 31 is formed on the entire inner wall surface of the main flow path 321 of the hydrogen gas flow path 32. The heat insulating coating may be formed, for example, by spraying alloy powder or the like onto the inner wall surface of the main flow path 321 by thermal spraying, by thermal spraying a ceramic material onto the inner wall surface of the main flow path 321, or by spray painting a heat insulating paint onto the inner wall surface of the main flow path 321.

[0036] In this embodiment, no thermal insulation coating is provided to surround the sub-flow passages 322, but a thermal insulation coating may be further provided to incorporate the sub-flow passages 322, if necessary. That is, the thermal insulation section 33B may have not only a thermal insulation coating surrounding the main flow passage 321, but also a thermal insulation coating surrounding each of the sub-flow passages 322.

[0037] According to the hydrogen tank structure 1B of this embodiment, a heat insulating coating having a lower thermal conductivity than the manifold body 31 is formed on the entire inner wall surface of the main flow path 321 of the hydrogen gas flow path 32, so that the heat transfer from the manifold 3 to the main flow path 321 of the hydrogen gas flow path 32 can be suppressed using the heat insulating coating, and the heat reception from the manifold 3 can be reduced. Therefore, when hydrogen is filled, the temperature rise of the filled hydrogen gas can be prevented, and the decrease in the amount of hydrogen filled due to the temperature rise can be suppressed. Furthermore, by doing so, there is no need to reduce the size of the manifold 3, so the drop resistance of the manifold 3 is not affected. As a result, the heat reception from the manifold 3 can be reduced without deteriorating the drop resistance.

[0038] [Fourth embodiment] Hereinafter, a fourth embodiment of the hydrogen tank structure will be described with reference to Figures 5 and 6. The hydrogen tank structure 1C of this embodiment differs from the first embodiment described above in the structure of the heat insulating part. The other structures are the same as those of the first embodiment, so duplicated explanations will be omitted.

[0039] 5, the heat insulating section 33C in this embodiment is a gas circulation path that communicates with the hydrogen gas flow path 32 and circulates hydrogen gas inside the manifold 3. Specifically, the heat insulating section 33C is located inside the manifold body 31 on the opposite side of the hydrogen gas flow path 32 from the hydrogen tank 2. The heat insulating section 33C extends along the longitudinal direction of the manifold body 31 so as to be parallel to the main flow path 321. The heat insulating section 33C has a circular cross section (see FIG. 6).

[0040] One longitudinal end of the heat insulating section 33C (more specifically, the end close to the In / Out connect 4) is blocked by a plug 7. Furthermore, a Venturi tube 9 for generating negative pressure is provided at the one end. The Venturi tube 9 is disposed inside the manifold body 31 so as to communicate between the heat insulating section 33C and the main flow path 321 of the hydrogen gas flow path 32, and the open end thereof is blocked by a plug 8.

[0041] On the other hand, the other end in the longitudinal direction of the heat insulating portion 33C is closed by an end plug 5. Furthermore, at the other end, the heat insulating portion 33C communicates with the main flow passage 321 of the hydrogen gas flow passage 32 via a communication passage .

[0042] According to the hydrogen tank structure 1C of this embodiment, the gas circulation path constituting the heat insulating section 33C is utilized to suppress heat transfer from the manifold 3 to the main flow path 321 of the hydrogen gas flow path 32, thereby making it possible to prevent a rise in temperature of the filled hydrogen gas. In addition, since there is no need to reduce the size of the manifold 3, the drop resistance of the manifold 3 is not affected.

[0043] Furthermore, the hydrogen tank structure 1C of this embodiment can suppress unevenness in the temperature of the filled hydrogen gas, as will be described in detail below.

[0044] Of the multiple hydrogen tanks 2 arranged in parallel, the hydrogen tank 2 closest to the In / Out connect 4 receives the least amount of heat from the manifold 3. And as the distance from the In / Out connect 4 increases, the cooled hydrogen gas receives heat from the manifold 3 for a longer period of time, and so the heat received from the manifold 3 also increases. For this reason, the temperature of the hydrogen gas flowing to the hydrogen tank 2 located furthest from the In / Out connect 4 is the highest. In other words, the temperature of the filled hydrogen gas becomes uneven depending on the distance from the In / Out connect 4.

[0045] In this embodiment, the main flow path 321 of the hydrogen gas flow path 32, the communication passage 10, the heat insulating section 33C (i.e., the gas circulation path), and the Venturi tube 9 form a circuit for circulating the filled hydrogen gas inside the manifold body 31. A portion of the cooled hydrogen gas circulates along the main flow path 321, the communication passage 10, the heat insulating section 33C, and the Venturi tube 9 due to the negative pressure of the Venturi tube 9, thereby making it possible to homogenize the temperature of the filled hydrogen gas. As a result, it is possible to suppress non-uniformity in the temperature of the filled hydrogen gas.

[0046] Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments, and various design modifications can be made without departing from the spirit of the present invention as described in the claims. [Explanation of symbols]

[0047] 1, 1A, 1B, 1C: hydrogen tank structure, 2: hydrogen tank, 3: manifold, 4: in / out connect, 5: end plug, 6, 10: communication passage, 7, 8: plug, 9: venturi tube, 21: tank body, 22: nozzle part, 23: nozzle body, 24: flange part, 31: manifold body, 32: hydrogen gas flow passage, 33, 33A, 33B, 33C: heat insulating part, 34: receiving recess, 231: male thread part, 321: main flow passage, 322: secondary flow passage, 341: female thread part

Claims

1. A hydrogen tank structure comprising a plurality of hydrogen tanks arranged in parallel and a long manifold connected to one end of each of the hydrogen tanks, The manifold comprises: a hydrogen gas flow path extending along a longitudinal direction of the manifold within the manifold and communicating with an interior of each hydrogen tank; a heat insulating portion provided in the vicinity of the hydrogen gas flow path; A hydrogen tank structure comprising:

2. the heat insulating portion is a hollow portion provided inside the manifold and extending along a longitudinal direction of the manifold, 2. The hydrogen tank structure according to claim 1, wherein when viewed from the longitudinal direction of the manifold, the hollow portion is formed with a C-shaped cross section so as to surround the hydrogen gas flow path, with an opening of the C facing toward the hydrogen tank.

3. The manifold further includes a manifold body in which the hydrogen gas flow path is provided, 2. The hydrogen tank structure according to claim 1, wherein the heat insulating portion is a heat insulating material arranged on an outer periphery of the manifold body so as to surround the manifold body.

4. 2. The hydrogen tank structure according to claim 1, wherein the heat insulating portion is a heat insulating coating provided on an inner wall surface of the hydrogen gas flow path.

5. 2. The hydrogen tank structure according to claim 1, wherein the heat insulating portion is a gas circulation path that communicates with the hydrogen gas flow path and circulates hydrogen gas inside the manifold.

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