Hydrogen tank structure
The hydrogen tank structure addresses temperature rise issues by integrating a heat insulating section near the gas flow path, ensuring stable hydrogen filling and maintaining drop resistance performance.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- TOYOTA JIDOSHA KK
- Filing Date
- 2023-06-08
- Publication Date
- 2026-05-11
AI Technical Summary
The existing hydrogen tank structures face issues with temperature rise due to heat transfer from the metal manifold, leading to reduced hydrogen filling capacity and compromised drop resistance performance when using smaller manifolds to mitigate heat mass.
Incorporating a heat insulating section near the hydrogen gas flow path within the manifold, which can be a cavity, heat insulating material on the manifold's outer circumference, a heat insulating coating on the inner wall, or a gas circulation path to reduce heat transfer and maintain temperature stability.
Prevents temperature rise of filled hydrogen gas, maintains hydrogen filling capacity, and preserves drop resistance performance by minimizing heat absorption from the manifold.
Smart Images
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Abstract
Description
Technical Field
[0001] The present invention relates to a hydrogen tank structure.
Background Art
[0002] Conventionally, as such a technical field, for example, there is one described in Patent Document 1. The hydrogen tank structure described in Patent Document 1 includes a plurality of small hydrogen tanks arranged in parallel, and a manifold that fixes these hydrogen tanks and fills 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
Summary of the Invention
Problems to be Solved by the Invention
[0004] However, in the above-described hydrogen tank structure, since the manifold is made of metal and the heat mass (i.e., heat capacity) of the manifold is large, when the cooled hydrogen gas passes through the hydrogen gas flow path inside the manifold, it receives heat from the manifold and the temperature rises. When the temperature rises, the amount of hydrogen filled into the tank decreases, and there is a problem that the tank cannot be filled to its full capacity. In order to solve this problem, it is considered to reduce the size of the manifold so as to reduce the heat mass, but a new problem arises in that the drop resistance performance of the manifold is reduced.
[0005] The present invention has been made to solve such technical problems, and an object thereof is 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 Problems
[0006] The hydrogen tank structure according to the present invention comprises a plurality of parallel hydrogen tanks and a long manifold connected to one end of each hydrogen tank, wherein the manifold has a hydrogen gas passage extending along the longitudinal direction of the manifold inside the manifold and communicating with the inside of each hydrogen tank, and a heat insulating section provided near the hydrogen gas passage.
[0007] In the hydrogen tank structure according to the present invention, the heat insulating section provided near the hydrogen gas flow path plays a role in suppressing heat transfer from the manifold to the hydrogen gas flow path, thereby suppressing the temperature rise of the hydrogen gas flowing through the hydrogen gas flow path. As a result, heat absorption from the manifold during hydrogen gas filling can be reduced, preventing a temperature rise in the filled hydrogen gas. Consequently, a decrease in the amount of hydrogen filled due to temperature rise can be suppressed.
[0008] In the hydrogen tank structure according to the present invention, the heat insulating portion is provided inside the manifold and is a cavity that extends along the longitudinal direction of the manifold. When viewed from the longitudinal direction of the manifold, the cavity is preferably formed in a C-shape in cross-section so as to surround the hydrogen gas flow path, with the opening of the C-shape facing the hydrogen tank side. In this way, the heat insulating portion suppresses heat transfer from the manifold to the hydrogen gas flow path, thereby reducing heat absorption from the manifold and preventing a rise in the temperature of the filled hydrogen gas.
[0009] In the hydrogen tank structure according to the present invention, the manifold further comprises a manifold body provided with the hydrogen gas passage, and the heat insulating portion is preferably a heat insulating material arranged on the outer circumference of the manifold body so as to surround the manifold body. In this case, by using the heat insulating material arranged on the outer circumference of the manifold body to block heat transfer from the external environment to the manifold body, the influence of the outside temperature on the manifold body can be reduced. As a result, heat transfer from the manifold to the hydrogen gas passage can be suppressed, and the temperature rise 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 and prevent the temperature of the filled hydrogen gas from rising.
[0011] In the hydrogen tank structure according to the present invention, the heat insulating section is preferably 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, heat transfer from the manifold to the hydrogen gas flow path can be suppressed to prevent a rise in the temperature of the filled hydrogen gas, and non-uniformity of the temperature of the filled hydrogen gas can be suppressed. [Effects of the Invention]
[0012] According to the present invention, heat transfer from the manifold to the hydrogen gas flow path can be suppressed, and the temperature rise of the filled hydrogen gas can be prevented. [Brief explanation of the drawing]
[0013] [Figure 1] This is a schematic cross-sectional view showing the hydrogen tank structure according to the first embodiment. [Figure 2] This is a cross-sectional view along lines AA and BB in Figure 1. [Figure 3] This is a cross-sectional view showing a hydrogen tank structure according to the second embodiment. [Figure 4]This is a cross-sectional view showing a hydrogen tank structure according to the third embodiment. [Figure 5] This is a schematic cross-sectional view showing a hydrogen tank structure according to the fourth embodiment. [Figure 6] This is a cross-sectional view along the CC and DD lines in Figure 5. [Modes for carrying out the invention]
[0014] Hereinafter, embodiments of the 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 denoted by the same reference numerals, and redundant explanations are omitted.
[0015] [First Embodiment] Figure 1 is a schematic cross-sectional view showing the hydrogen tank structure according to the first embodiment, and Figure 2 is a cross-sectional view along lines AA and BB in Figure 1. In Figure 1, the state before the hydrogen tank 2 is inserted into the receiving recess 34 (described later) of the manifold 3 is shown in order to make the structure of the receiving recess 34 of the manifold 3 easier to understand.
[0016] The hydrogen tank structure 1 of this embodiment is, for example, mounted on a fuel cell vehicle (not shown), and comprises a plurality of parallel hydrogen tanks 2 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 narrowed opening and is a high-pressure vessel having a space inside for storing hydrogen gas. This hydrogen tank 2 has a substantially cylindrical tank body 21 and a nozzle portion 22 attached to the open end of the tank body 21. Although not shown, the tank body 21 has a substantially cylindrical liner with dome-shaped rounded ends and a fiber-reinforced resin layer covering the outer surface of the liner. The liner may be made of aluminum or resin.
[0018] The base part 22 is processed into a cylindrical shape from a metal material such as stainless steel or aluminum alloy, and has a cylindrical base body 23 extending along the axial direction of the hydrogen tank 2, and a flange part 24 connected to one end of the base body 23 and protruding in the radial direction. The base part 22 is fixed to the opening end part by screwing in a state of being externally inserted into the opening end part of the tank body 21.
[0019] Further, on the outer peripheral wall of the base body 23, a male screw part 231 that is screwed with a female screw part 341 formed in the receiving recessed part 34 of the manifold 3 is formed. The flange part 24 serves to enhance the strength of the entire base part 22 and to regulate the screwing depth when screwing with the manifold 3, and is integrally formed with the base body 23.
[0020] As shown in FIG. 1, a plurality of hydrogen tanks 2 having such a structure are arranged side by side along one direction. Each hydrogen tank 2 is connected to the manifold 3 by screwing the male screw part 231 and the female screw part 341 of the receiving recessed part 34 in a state of being inserted into the receiving recessed part 34 of the manifold 3.
[0021] The manifold 3 is a metal member that serves to fix a plurality of hydrogen tanks 2 and to fill hydrogen gas into the interior of each hydrogen tank 2. In the present embodiment, the manifold 3 is formed of, for example, an aluminum extrusion material.
[0022] The manifold 3 has a long manifold body 31 having a rectangular cross section, a hydrogen gas flow path 32 provided inside the manifold body 31, and a heat insulating part 33 provided in the vicinity of the hydrogen gas flow path 32.
[0023] The manifold body 31 is provided with multiple receiving recesses 34 for receiving the nozzle portion 22 of the hydrogen tank 2. As shown in Figure 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 of the manifold body 31 (the hydrogen tank 2 side). The receiving recesses 34 consist of cylindrical cavities and open toward the hydrogen tank 2. The inner circumferential wall of the receiving recess 34 has a female threaded portion 341 formed therein for screwing into the male threaded portion 231 of the nozzle portion 22 of the hydrogen tank 2.
[0024] The hydrogen gas flow path 32 is positioned approximately in the center of the manifold body 31 and has a main flow path 321 that extends along the longitudinal direction of the manifold body 31, and a plurality of sub-flow paths 322 that branch off from the main flow path 321 and connect the main flow path 321 to the receiving recess 34. The main flow path 321 has a circular cross-section, one end in the longitudinal direction is connected to the In / Out connect 4, and the other end is closed by the end plug 5. The sub-flow paths 322 are provided one-to-one for the plurality of receiving recesses 34. The sub-flow paths 322 are positioned 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 an In / Out connect 4. During hydrogen refueling, the hydrogen gas supplied from the hydrogen station flows through the valve and In / Out connect 4 into the main flow path 321 in a cooled state (e.g., -40°C), and then flows into the hydrogen tank 2 via the sub-flow path 322.
[0026] The heat insulating section 33 consists of a cavity that extends along the longitudinal direction of the manifold body 31 inside the manifold body 31. As shown in Figure 2, when viewed from the longitudinal direction of the manifold body 31, the heat insulating section 33 (i.e., the cavity) is formed in a C-shape in cross-section so as to surround the hydrogen gas flow path 32, with the C-shaped opening facing the hydrogen tank 2 side.
[0027] As shown in Figure 1, one end of the thermal insulation section 33 in the longitudinal direction is closed by the In / Out connect 4, and the other end is closed by the end plug 5. On the In / Out connect 4 side, the thermal insulation section 33 communicates with the hydrogen gas flow path 32 via the communication passage 6. During hydrogen filling, hydrogen gas flows into the thermal insulation section 33 (i.e., the cavity) via the communication passage 6, but since the other end of the thermal insulation section 33 is closed by the end plug 5, no hydrogen gas flow occurs.
[0028] As shown in Figure 2, the main channel 321 of the hydrogen gas channel 32 is located inside the C-shaped insulated section 33. On the other hand, the secondary channel 322 of the hydrogen gas channel 32 passes through the opening of the C-shaped insulated section 33 and connects the main channel 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 path 32 via a connecting passage 6, so the pressure in the heat insulating section 33 and the pressure in the hydrogen gas flow path 32 are the same. Furthermore, since the heat insulating section 33 has a C-shaped cross-section and surrounds the main flow path 321 of the hydrogen gas flow path 32, heat transfer from the manifold 3 to the main flow path 321 of the hydrogen gas flow path 32 is suppressed, and heat absorption from the manifold 3 can be reduced. Therefore, when filling with hydrogen, 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. Moreover, by doing so, there is no need to reduce the size of the manifold 3, so the drop resistance performance of the manifold 3 is not affected. As a result, heat absorption from the manifold 3 can be reduced without reducing the drop resistance performance.
[0030] [Second Embodiment] A second embodiment of the hydrogen tank structure will be described below with reference to Figure 3. The hydrogen tank structure 1A of this embodiment differs from the first embodiment described above in the structure of the heat insulating section. The other structures are the same as those of the first embodiment, so a redundant explanation will be omitted.
[0031] As shown in Figure 3, the heat insulating section 33A in this embodiment is a heat insulating material arranged on the outer circumference of the manifold body 31 so as to surround the manifold body 31. More specifically, the heat insulating section 33A is formed into a rectangular tube shape by wrapping a sheet-like heat insulating material around the outer surface of the manifold body 31. The heat insulating material is tightly adhered to the outer surface of the manifold body 31 with, for example, an adhesive. Note that the heat insulating section 33A is not provided in the locations where the receiving recess 34 is formed so as not to interfere with the insertion of the hydrogen tank 2.
[0032] The insulation material may be, for example, a synthetic resin foam or a fibrous insulation material. As the synthetic resin foam, a closed-cell foam such as polyethylene, polypropylene, polystyrene, polyurethane, or phenolic resin can be used. As the fibrous insulation material, glass fiber, polyester or nylon nonwoven fabrics, cellulose fiber, etc., can be used.
[0033] According to the hydrogen tank structure 1A of this embodiment, by using an insulating material placed on the outer circumference of the manifold body 31 to block heat transfer from the external environment to the manifold body 31, the influence of the outside temperature on the manifold body 31 can be reduced. This suppresses heat transfer from the manifold 3 to the hydrogen gas flow path 32 and reduces heat absorption from the manifold 3. Therefore, when hydrogen is filled, it is possible to prevent the temperature of the filled hydrogen gas from rising and to suppress the decrease in the amount of hydrogen filled due to the temperature rise. Furthermore, since the insulating material is placed on the outer circumference of the manifold body 31 so as to surround the manifold body 31, it can also act as a buffer to protect the manifold body 31 and improve the drop resistance of the manifold 3.
[0034] [Third Embodiment] A third embodiment of the hydrogen tank structure will be described below with reference to Figure 4. The hydrogen tank structure 1B of this embodiment differs from the first embodiment described above in the structure of the heat insulating section. The other structures are the same as those of the first embodiment, so a redundant explanation will be omitted.
[0035] As shown in Figure 4, the heat insulating portion 33B in 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 with 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 a melted alloy powder or the like onto the inner wall surface of the main flow path 321 by thermal spraying, or by thermal spraying a ceramic material onto the inner wall surface of the main flow path 321, or by spray-painting a heat insulating coating onto the inner wall surface of the main flow path 321.
[0036] In this embodiment, a thermal insulation coating is not provided around the sub-channel 322, but if necessary, a thermal insulation coating to accommodate the sub-channel 322 may be further provided. That is, the thermal insulation section 33B may have thermal insulation coatings not only around the main channel 321, but also around each sub-channel 322.
[0037] In the hydrogen tank structure 1B of this embodiment, a heat insulating coating with lower thermal conductivity than the manifold body 31 is formed on the entire inner wall surface of the main passage 321 of the hydrogen gas passage 32. Therefore, heat transfer from the manifold 3 to the main passage 321 of the hydrogen gas passage 32 can be suppressed using the heat insulating coating, thereby reducing heat absorption from the manifold 3. Consequently, it is possible to prevent a rise in the temperature of the hydrogen gas being filled during hydrogen filling, and to suppress a decrease in the amount of hydrogen being filled due to the temperature rise. Furthermore, by doing so, it is not necessary to reduce the size of the manifold 3, so the drop resistance performance of the manifold 3 is not affected. As a result, it is possible to reduce heat absorption from the manifold 3 without reducing the drop resistance performance.
[0038] [Fourth Embodiment] A fourth embodiment of the hydrogen tank structure will be described below 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 section. The other structures are the same as those of the first embodiment, so a redundant explanation will be omitted.
[0039] As shown in Figure 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 side opposite the hydrogen tank 2 to the hydrogen gas flow path 32. This 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 Figure 6).
[0040] Furthermore, one end of the heat insulating section 33C in the longitudinal direction (more specifically, the end closer to the In / Out connect 4) is sealed by a plug 7. In addition, a venturi tube 9 for generating negative pressure is provided at this end. The venturi tube 9 is positioned inside the manifold body 31 so as to connect the heat insulating section 33C with the main flow path 321 of the hydrogen gas flow path 32, and its open end is sealed by a plug 8.
[0041] On the other hand, the other end of the heat insulating section 33C in the longitudinal direction is closed by the end plug 5. Furthermore, at this other end, the heat insulating section 33C is in communication with the main flow path 321 of the hydrogen gas flow path 32 via the communication passage 10.
[0042] According to the hydrogen tank structure 1C of this embodiment, the gas circulation path constituting the heat-insulating section 33C is used to suppress heat transfer from the manifold 3 to the main passage 321 of the hydrogen gas passage 32, thereby preventing a rise in the temperature of the filled hydrogen gas. Furthermore, since there is no need to reduce the size of the manifold 3, the drop resistance performance of the manifold 3 is not affected.
[0043] Furthermore, the hydrogen tank structure 1C of this embodiment can suppress temperature non-uniformity of the filled hydrogen gas. This will be explained in detail below.
[0044] Of the multiple parallel hydrogen tanks 2, the hydrogen tank 2 located closest to the In / Out connect 4 receives the least heat from the manifold 3. As the distance from the In / Out connect 4 increases, the cooled hydrogen gas receives heat from the manifold 3 for a progressively longer period, resulting in greater heat absorption from the manifold 3. Consequently, the hydrogen gas flowing through the hydrogen tank 2 located furthest from the In / Out connect 4 has the highest temperature. 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, connecting passage 10, insulating section 33C (i.e., gas circulation path) of the hydrogen gas flow path 32, and the venturi tube 9 form a circuit for circulating the filled hydrogen gas inside the manifold body 31. Due to the negative pressure in the venturi tube 9, a portion of the cooled hydrogen gas circulates along the main flow path 321, connecting passage 10, insulating section 33C, and venturi tube 9, thereby equalizing the temperature of the filled hydrogen gas. As a result, it becomes possible to suppress temperature unevenness of the filled hydrogen gas.
[0046] Although embodiments of the present invention have been described in detail above, the present invention is not limited to the embodiments described above, and various design modifications can be made without departing from the spirit of the 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: Connecting passage, 7,8: Plug, 9: Venturi tube, 21: Tank body, 22: Nozzle section, 23: Nozzle body, 24: Flange section, 31: Manifold body, 32: Hydrogen gas flow path, 33,33A,33B,33C: Insulation section, 34: Receiving recess, 231: Male thread section, 321: Main flow path, 322: Sub-flow path, 341: Female thread section
Claims
1. A hydrogen tank structure comprising multiple parallel hydrogen tanks and a long manifold connected to one end of each hydrogen tank, The aforementioned manifold is Within the manifold, a hydrogen gas flow path extends along the longitudinal direction of the manifold and communicates with the interior of each hydrogen tank, A heat insulating section provided near the hydrogen gas flow path, It has, The aforementioned heat insulating portion is provided inside the manifold and is a cavity that extends along the longitudinal direction of the manifold. A hydrogen tank structure characterized in that, when viewed from the longitudinal direction of the manifold, the cavity is formed in a C-shape in cross-section so as to surround the hydrogen gas flow path, and the C-shaped opening faces the hydrogen tank side.
2. A hydrogen tank structure comprising a plurality of parallel hydrogen tanks and a long manifold connected to one end of each hydrogen tank, The aforementioned manifold is Within the manifold, a hydrogen gas flow path extends along the longitudinal direction of the manifold and communicates with the interior of each hydrogen tank, A heat insulating section provided near the hydrogen gas flow path, It has, The hydrogen tank structure is characterized in that the heat insulating portion is a heat insulating coating provided on the inner wall surface of the hydrogen gas flow path.
3. A hydrogen tank structure comprising a plurality of parallel hydrogen tanks and a long manifold connected to one end of each hydrogen tank, The aforementioned manifold is Within the manifold, a hydrogen gas flow path extends along the longitudinal direction of the manifold and communicates with the interior of each hydrogen tank, A heat insulating section provided near the hydrogen gas flow path, It has, The hydrogen tank structure is characterized in that the heat insulating section is a gas circulation path that communicates with the hydrogen gas flow path and circulates hydrogen gas inside the manifold.