High pressure tank

Abstract

The high-pressure tank of the present invention includes a tank body, a deformation sensor disposed on the tank body, and a storage section disposed on the tank body. The storage section is configured to store the number of times fuel gas is filled into the high-pressure tank based on the deformation count of the deformation sensor.

Description

Technical Field

[0001] The technology disclosed in this specification relates to high-pressure tanks for storing fuel gases. Background Technology

[0002] Japanese Patent Application Publication No. 2019-44863 discloses a high-pressure tank equipped with a strain gauge. The strain gauge is connected to a pressure measuring unit. The pressure measuring unit uses the deformation value received from the strain gauge to calculate the internal pressure of the high-pressure tank. By monitoring the internal pressure through the pressure measuring unit, the number of times fuel gas needs to be filled can be calculated.

[0003] High-pressure tanks undergo repeated expansion and contraction due to gas filling and releasing, necessitating tank replacement corresponding to a specified number of filling cycles. Furthermore, there are instances of using second-hand high-pressure tanks. However, the technology described in Japanese Patent Application Laid-Open No. 2019-44863 does not establish a direct correlation between the calculated number of filling cycles and the high-pressure tank. Therefore, it is impossible to properly manage the lifespan of the high-pressure tank. This leads to potential issues such as the possibility of failing to reuse tanks with the correct filling cycles or the possibility of altering the filling cycle count, making it difficult to guarantee the lifespan of second-hand high-pressure tanks. Summary of the Invention

[0004] The high-pressure tank disclosed in this specification includes a tank body, a deformation sensor disposed on the tank body, and a storage unit disposed on the tank body. The storage unit is configured to store the number of times fuel gas has been filled into the high-pressure tank based on the deformation count measured by the deformation sensor.

[0005] According to the above structure, the tank body has a storage section capable of storing a certain number of fills of fuel gas. This allows the high-pressure tank itself to retain a certain number of fills. The lifespan of the high-pressure tank can be appropriately managed. Therefore, even when the high-pressure tank is removed from a vehicle and used as a second-hand part, its lifespan can still be guaranteed. The life cycle of the high-pressure tank can be rationalized.

[0006] The tank body may also have a liner, a reinforcing layer covering the outer periphery of the liner, and a connector mounted on the liner with a clamping hole for clamp engagement. A partition separating the interior and exterior of the high-pressure tank may also be provided at the bottom of the clamping hole. A deformation sensor may also be disposed in the partition. The partition portion is thinner than the portion without the clamping hole, making it an area prone to deformation in response to the internal pressure of the high-pressure tank. Therefore, the partition can function as a diaphragm for detecting deformation. The connector and diaphragm structures can be shared, thus reducing the number of components. This enables miniaturization and cost reduction of the deformation sensor.

[0007] The tank body can also have a liner, a reinforcing layer covering the outer periphery of the liner, and a flanged connector mounted on the liner. A deformation sensor can also be configured on the flange. The flange portion is thinner than the main body of the connector, making it an area that easily deforms in response to the internal pressure of the high-pressure tank. That is, the flange has high sensitivity to displacement caused by internal pressure, thus functioning as a diaphragm for detecting deformation. The connector and diaphragm structures can be shared, thus reducing the number of components. This enables miniaturization and cost reduction of the deformation sensor.

[0008] The vehicle can also be equipped with the high-pressure tank described in technical solution 1. The vehicle can also be equipped with a control unit configured to communicate with the storage unit. The control unit can also be configured to report to the user that the number of refills received from the storage unit has reached a predetermined number. This allows the user to identify when the high-pressure tank needs to be replaced, enabling safe use of the high-pressure tank.

[0009] The detailed description of the technology disclosed in this specification and further improvements are described in the following "Detailed Description".

[0010] The features, advantages, and technical and industrial significance of exemplary embodiments of the present invention will now be described with reference to the accompanying drawings, in which the same reference numerals denote the same elements. Attached Figure Description

[0011] Figure 1 This is a simplified cross-sectional view of hydrogen tank 10.

[0012] Figure 2 This is an enlarged sectional view of the area near the second connector 42.

[0013] Figure 3 This is an enlarged cross-sectional view of the hydrogen tank 210 in Example 2.

[0014] Figure 4 This is an enlarged sectional view of the vicinity of the second joint 42 involved in the modified example. Detailed Implementation

[0015]

Example 1

[0016] <Structure of Hydrogen Tank 10>

[0017] exist Figure 1 A simplified cross-sectional view of the hydrogen tank 10 is shown. The hydrogen tank 10 is used, for example, as a supply source for storing high-pressure hydrogen and supplying hydrogen to a fuel cell. The hydrogen tank 10 includes a liner 20, a reinforcing layer 30, a first connector 41, and a second connector 42. These components constitute the tank body.

[0018] Liner 20 is a component forming the inner layer of hydrogen tank 10, and has a hollow cylindrical shape. Liner 20 is a resin container for storing hydrogen. An opening 21 is formed at the end in the -x direction, and an opening 22 is formed at the end in the +x direction. Reinforcing layer 30 is a layer formed on the outer peripheral surface of liner 20 to reinforce liner 20. Reinforcing layer 30 may, for example, comprise an outer layer of fiber-reinforced resin. Reinforcing layer 30 may, for example, be formed of carbon fiber reinforced plastic (CFRP).

[0019] The first connector 41 is a generally cylindrical component. The first connector 41 has a through hole 41h and a flange 41f. The flange 41f protrudes outward from the outer periphery of the first connector 41 and is a convex-edge component. The flange 41f is formed around the entire circumference of the outer periphery of the first connector 41. The flange 41f is integrally fixed to the liner 20 by blocking the opening 21 of the liner 20. The through hole 41h communicates with the interior of the liner 20. The through hole 41h is the part for fixing by screwing in a valve assembly (not shown). The valve assembly has an inflow passage and an outflow passage. The inflow passage is for filling the hydrogen tank 10 with hydrogen from an external hydrogen source. The outflow passage is for supplying hydrogen from the hydrogen tank 10 to the fuel cell (not shown). Additionally, a main shut-off valve (not shown), a manual valve, a check valve, etc., are provided in the inflow and outflow passages.

[0020] The second connector 42 has clamping holes 42j1 and 42j2 and a flange 42f. The flange 42f is a convex edge-shaped component that protrudes outward from the outer periphery of the second connector 42. The flange 42f is formed around the entire circumference of the outer periphery of the second connector 42. The flange 42f is integrally fixed to the liner 20 by blocking the opening 22 of the liner 20. The clamping holes 42j1 are for engaging with a clamp (not shown). By means of the clamp, the hydrogen tank 10 can be rotatably held during the process of forming the reinforcing layer 30 on the hydrogen tank 10.

[0021] The bottoms of clamp holes 42j1 and 42j2 are arranged opposite each other via deformation detection units 43. That is, the deformation detection unit 43, located at the bottom of clamp hole 42j1, functions as a partition separating the interior and exterior of the hydrogen tank 10. Therefore, the second connector 42 does not communicate with the interior of the lining 20. Furthermore, in Figure 1 In the text, components such as the deformation sensor 44 and the storage unit 47, which are located inside the fixture hole 42j1, are omitted from the description.

[0022] <Structure near joint 42>

[0023] exist Figure 2The diagram shows an enlarged cross-sectional view near the second connector 42. The second connector 42 includes a deformation detection unit 43, a deformation sensor 44, a wire 45, a housing 46, a storage unit 47, an internal connector 48, and a light-emitting unit 49. For ease of illustration, the second connector 42, the deformation detection unit 43, the deformation sensor 44, and the housing 46 are shown in cross-sectional views, while other parts are shown in simplified block diagrams.

[0024] The deformation detection unit 43, deformation sensor 44, wire 45, housing 46, storage unit 47, internal connector 48, and light-emitting unit 49 are disposed inside the clamp hole 42j1. The clamp hole 42j1 is a hole used during the formation of the reinforcing layer 30, and therefore is not used after the tank body is completed. Thus, by using the clamp hole 42j1 as a container for storing these components, the size of the hydrogen tank 10 can be reduced. In addition, in the event of external force applied by a vehicle collision or the like, these components can be protected by the second connector 42.

[0025] The deformation detection unit 43 is a component that isolates the clamp holes 42j1 and 42j2. A recess 43r is formed in the deformation detection unit 43. The deformation detection unit 43 functions as a diaphragm by deforming under pressure through the recess 43r. The deformation detection unit 43 is independently constructed from the second connector 42. This allows for a wider range of material choices for the deformation detection unit 43. By selecting a material with good pressure-deformation characteristics, the detection accuracy of the deformation detection unit 43 can be improved. Furthermore, a hydrogen-permeable coating can be applied to the deformation detection unit 43. This suppresses changes in output characteristics caused by hydrogen permeation.

[0026] The housing 46 has a threaded portion 46s. By screwing the housing 46 into the -x direction, the deformation detection unit 43 can be pressed and fixed to the bottom surface 42b of the clamp hole 42j1. In addition, the housing 46 has an opening 46a through which the wire 45 can pass.

[0027] A deformation sensor 44 is disposed within a deformation detection unit 43, which functions as a partition. The deformation sensor 44 is a unit that converts the displacement of the deformation detection unit 43 into an electrical signal and outputs it. The deformation sensor 44 includes a strain gauge (not shown) and a sensor chip. In this embodiment, the strain gauge is a metal strain gauge with a resistive element made of metal. A wire 45 transmits an electrical signal from the deformation sensor 44 to the storage unit 47.

[0028] The storage unit 47 includes a CPU 47c and a non-volatile memory 47m. The CPU 47c calculates the pressure exerted on the deformation detection unit 43 by the hydrogen inside the hydrogen tank 10 based on the deformation measured by the deformation sensor 44. In addition, the CPU 47c counts the number of times hydrogen is filled into the hydrogen tank 10 and stores the counted number of fillings in the non-volatile memory 47m. The detailed operation of the storage unit 47 will be described later.

[0029] The light-emitting part 49 is a component that can be controlled to light up or turn off based on instructions from the CPU 47c. In this embodiment, the light-emitting part 49 is an LED.

[0030] An internal connector 48 connects to a storage unit 47. An external connector 61 is engaged with the internal connector 48. The external connector 61 connects to the vehicle ECU 63 via a wiring harness 62. This constitutes a vehicle in which the vehicle ECU 63 and the storage unit 47 can communicate with each other. The vehicle ECU 63 is connected to a display 64 and an external communication interface 65. The display 64 is located in the driver's seat and is used to report various information to the user. The external communication interface 65 is used for various communication communication mechanisms (CMs) with the external hydrogen station 70. The communication CM is not particularly limited and can be wireless or wired communication via cable.

[0031] <The Actions of Hydrogen Tank 10>

[0032] An example of the operation of counting the number of times hydrogen is filled into the hydrogen tank 10 will be described. If the deformation detection unit 43 is deformed by the pressure of the hydrogen inside the hydrogen tank 10, the strain gauge of the deformation sensor 44 will also deform proportionally, thereby changing the resistance value of the resistive element. The change in resistance value is detected by the sensor chip and converted into a deformation value. The converted deformation value is sent to the storage unit 47 via the wire 45. The CPU 47c of the storage unit 47 uses the received deformation value to calculate the pressure exerted on the deformation detection unit 43 by the hydrogen inside the hydrogen tank 10. Furthermore, the method of calculating the pressure is not particularly limited. For example, the internal pressure of the hydrogen tank 10 can also be calculated by establishing a mapping between deformation and pressure. The mapping can also be pre-stored in the non-volatile memory 47m.

[0033] Furthermore, the CPU 47c counts the number of times hydrogen filling has been performed by monitoring changes in the pressure applied to the deformation detection unit 43. Moreover, the method for counting the number of fillings is not particularly limited, and various methods can be used. In this embodiment, the CPU 47c monitors whether the pressure rises and exceeds a predetermined filling threshold. If the pressure rise exceeds the filling threshold, it can be determined that hydrogen filling has occurred. In this case, the CPU 47c increments the number of fillings stored in the non-volatile memory 47m by 1.

[0034] Furthermore, the filling threshold only needs to be set larger than the maximum pressure increase that may occur due to temperature changes, etc. This prevents errors in counting the number of fillings caused by pressure fluctuations.

[0035] The number of refill cycles stored in the non-volatile memory 47m is sent to the vehicle ECU 63 via the internal connector 48, the external connector 61, and the wiring harness 62. The vehicle ECU 63 monitors whether the number of refill cycles has reached a predetermined number. The predetermined number of refill cycles is appropriately determined based on the safety factor of the hydrogen tank 10. When the predetermined number of refill cycles is reached, the vehicle ECU 63 displays a warning indicating that the hydrogen tank 10 is nearing the end of its lifespan on the display 64. This allows the user to be notified that the hydrogen tank 10 needs to be replaced, ensuring the safe use of the hydrogen tank 10.

[0036] Furthermore, before hydrogen refilling begins at the hydrogen station 70 into the hydrogen tank 10, the vehicle ECU 63 communicates with the hydrogen station 70 via a communication mechanism (CM). Moreover, if the prescribed number of refills has been reached, hydrogen refilling is restricted. For example, the maximum refill amount is reduced, or the system is set to a state where refilling is not possible. This helps prevent accidents caused by the hydrogen tank 10 nearing the end of its lifespan.

[0037] The CPU 47c of the storage unit 47 controls the light-emitting unit 49 to illuminate when the pressure detected by the deformation detection unit 43 is higher than a safety threshold, and to extinguish when the pressure is lower than the safety threshold. The safety threshold only needs to be preset to a value that ensures the safety of operators during the replacement, disposal, and handling of the hydrogen tank 10. In this embodiment, the safety threshold is set to 1 MPa. Therefore, operators can easily determine the internal pressure status of the hydrogen tank 10 by checking whether the light-emitting unit 49 is illuminated. This reduces the workload for measuring the internal pressure of the hydrogen tank 10 and ensures operational safety.

[0038] <Effect>

[0039] The problem is explained below. Hydrogen tanks repeatedly expand and contract due to the filling and releasing of gas, thus requiring replacement when the number of fillings reaches a specified number. Furthermore, there are cases where used high-pressure tanks are used. However, in the prior art, it is not possible to directly establish a correspondence between the number of fillings and the high-pressure tank. Therefore, it is impossible to properly manage the lifespan of the high-pressure tank. This leads to possibilities such as the failure to reuse fillings or the possibility of altering the filling count, making it difficult to guarantee the lifespan of used hydrogen tanks. Therefore, to ensure the safety of hydrogen tanks even when the number of fillings is unknown, regulations stipulate that a very high safety rate must be met as a test condition (e.g., withstanding approximately 11,000 fillings). Exceeding the safety rate specification results in increased manufacturing costs, size, and weight of the hydrogen tank. Therefore, the hydrogen tank 10 in this specification has a structure in which the tank body has a storage section 47 capable of storing the number of fillings of fuel gas. This allows the hydrogen tank 10 itself to maintain its filling count, thus enabling proper management of the hydrogen tank 10's lifespan. Because the number of filling cycles can be accurately determined, the lifespan of the hydrogen tank 10 can be controlled based on tank replacement. Therefore, the safety margin can be rationalized, thereby controlling the manufacturing cost, size, and weight of the hydrogen tank 10.

[0040] In the hydrogen tank 10 described in this specification, a storage section 47 is disposed inside the second connector 42 that constitutes the main body of the tank. That is, the storage section 47 is integrally formed with the hydrogen tank 10. Therefore, when the hydrogen tank 10 is removed or installed in other vehicles, the number of filling cycles can be reliably maintained. In addition, since it is difficult to disassemble the second connector 42 to remove the storage section 47, it is possible to prevent the alteration of the number of filling cycles.

[0041] In the hydrogen tank 10 of this specification, the deformation detection unit 43, which functions as a partition wall, can function as a diaphragm for detecting deformation. Since the structure of the second connector 42 and the diaphragm structure can be shared, the number of components can be reduced. This enables miniaturization and cost reduction of the hydrogen tank 10.

[0042] Previously, pressure sensors were installed via valves and piping, which narrowed and lengthened the flow path, resulting in pressure loss. In the hydrogen tank 10 of this specification, the deformation sensor 44 can be installed without valves and piping. Therefore, pressure loss caused by the sensor installation structure can be suppressed.

[0043]

Example 2

[0044] <Structure of Hydrogen Tank 210>

[0045] exist Figure 3The figure shows an enlarged cross-sectional view near the second connector 42 in the hydrogen tank 210 of Embodiment 2. The deformation sensor 44 is positioned differently in the hydrogen tank 210 of Embodiment 2 compared to the hydrogen tank 10 of Embodiment 1. Description is omitted by using the same reference numerals for common parts between hydrogen tank 210 and hydrogen tank 10.

[0046] The deformation sensor 44 is disposed on the outer surface of the flange 42f. The deformation sensor 44 is fixed by being clamped by the flange 42f and the reinforcing layer 30. A storage unit 47, an internal connector 48, and a light-emitting unit 49 are disposed inside the clamping hole 42j1. The deformation sensor 44 is connected to the storage unit 47 via a wire 45.

[0047] Flange 42f is a plate-like component that protrudes outward from the outer periphery of the second connector 42. Therefore, it deforms outward (arrow A1 side) with the base BA as the fulcrum in response to an increase in internal pressure of the hydrogen tank 210. Conversely, it deforms inward (arrow A2 side) with the base BA as the fulcrum in response to a decrease in internal pressure of the hydrogen tank 210. This allows flange 42f to function as a cantilevered diaphragm. Furthermore, the deformation of flange 42f can be measured by deformation sensor 44.

[0048] <Effect>

[0049] In Embodiment 1, the deformation detection unit 43 functions as a diaphragm that maintains the entire circumference of the outer periphery of the recess 43r. On the other hand, in Embodiment 2, the flange 42f functions as a cantilevered diaphragm. The cantilevered diaphragm is more easily deformed due to its free end. That is, the cantilevered diaphragm is more sensitive to displacement caused by the internal pressure of the hydrogen tank 210. Therefore, in the hydrogen tank 210 of Embodiment 2, the sensitivity for measuring internal pressure can be further improved. Furthermore, the structure of the second connector 42 and the diaphragm structure can be shared, thus reducing the number of components. This enables miniaturization and cost reduction of the hydrogen tank 210.

[0050] The specific examples of the present invention have been described in detail above, but these are merely illustrative and do not limit the scope of the claims. The technology described in the claims includes technologies modified or altered from the specific examples described above. The technical elements described in this specification or drawings are useful individually or in various combinations, and are not limited to the combinations described in the claims at the time of application. Furthermore, the technology illustrated in this specification or drawings can achieve multiple objectives simultaneously, and achieving one of these objectives is itself technically useful.

[0051] <Variation Example>

[0052] The construction of the deformation detection unit 43 is not limited to the examples described in this specification, and can be various. For example, such as Figure 4As shown, a partition wall 42w can also be formed at a position opposite to the bottom of the clamp hole 42j1 and the bottom of the clamp hole 42j2. A deformation sensor 44 can also be mounted on the partition wall 42w. The partition wall 42w is integrally formed with the second connector 42 and functions as a diaphragm. The deformation of the partition wall 42w can be measured by the deformation sensor 44. Since the structure of the second connector 42 and the diaphragm structure can be shared, the number of components can be reduced.

[0053] The location for counting the number of hydrogen refills is not limited to the storage unit 47. For example, the pressure value measured by the deformation sensor 44 can be sent to the vehicle ECU 63 via the wiring harness 62. The number of hydrogen refills can also be counted by the vehicle ECU 63 based on the pressure changes of the hydrogen tank 10. The number of refills counted by the vehicle ECU 63 can also be sent to the storage unit 47 via the wiring harness 62 and stored in the non-volatile memory 47m.

[0054] The technology described in this specification is not limited to hydrogen tank 10 filled with hydrogen gas. The technology can be applied to any high-pressure tank capable of filling various substances. For example, it can also be applied to high-pressure tanks filled with CNG (compressed natural gas).

[0055] Figure 2 The structure shown is one example. For example, it may also include a seal that seals the housing 46 and the wire 45.

[0056] Deformation detection unit 43 is an example of the adjacent unit. Vehicle ECU 63 is an example of the control unit.

Claims

1. A high-pressure tank comprising: a liner having a cylindrical shape; a reinforcing layer covering an outer periphery of the liner; a first joint provided at one end side of the liner and having a gas inflow passage and a gas outflow passage; a second joint provided at the other end side of the liner, the second joint having a jig hole in which a jig is engageable; a partition wall disposed inside the jig hole to partition an inside of the liner from an outside of the liner, the partition wall being separate from the second joint; and a deformation sensor provided to the partition wall and disposed outside of the liner, wherein a recessed portion is formed in the partition wall, the recessed portion deforms due to pressure, the recessed portion faces the inside of the liner, and the deformation sensor is disposed in a region of the outside of the liner corresponding to the recessed portion.

2. A high-pressure tank comprising: a liner having a cylindrical shape; a first joint provided at one end side of the liner and having a gas inflow passage and a gas outflow passage; a second joint provided at the other end side of the liner, the second joint including a plate-shaped flange and a base portion, the plate-shaped flange protruding outward from an outer peripheral surface of the second joint; a reinforcing layer covering an outer periphery of the liner and an outer side surface of the flange; and a deformation sensor disposed on the outer side surface of the flange and fixed by being sandwiched by the flange and the reinforcing layer, wherein the flange deforms outward of the high-pressure tank with the base portion as a fulcrum in correspondence with an increase in internal pressure of the high-pressure tank, and deforms inward of the high-pressure tank with the base portion as a fulcrum in correspondence with a decrease in internal pressure of the high-pressure tank. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​

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