Tank inspection methods

Abstract

To provide a tank inspection method with which water injected into a tank during inspection can be efficiently discharged.SOLUTION: A tank inspection method TIM includes a support step P1, a water injection step P2, a pressure increase step P3, and a water discharge step P4. The support step P1 includes supporting a tank while crossing a central axis with a horizontal plane so that openings provided at both ends in a direction along the central axis of the tank are an upper opening and a lower opening. The water injection step P2 includes injecting water into the tank from the lower opening of the tank and exhausting air inside the tank from the upper opening. The pressure increase step P3 includes increasing the water pressure inside the tank to a predetermined pressure by pressure-feeding water to the lower opening in a state where an upper valve for opening and closing an upper channel connected with the upper opening is closed. The water discharge step P4 includes discharging water from the lower opening of the tank.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a method for inspecting a tank. [Background technology]

[0002] BACKGROUND ART A tank inspection method has been known in the past in which water is injected into the tank to increase the pressure inside the tank (see Patent Document 1 below). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2017-125733 Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure provides a tank inspection method that allows for efficient drainage of water injected into the tank during inspection. [Means for solving the problem]

[0005] One aspect of the present disclosure is a method for inspecting a tank, comprising: a support step of supporting the cylindrical tank by crossing the central axis with a horizontal plane so that openings provided at both ends of the central axis of the tank become an upper opening and a lower opening; a water filling step of pouring water into the tank from the lower opening of the tank supported in the support step and discharging air from inside the tank from the upper opening; a pressurization step of pumping water to the lower opening while closing an upper valve that opens and closes an upper flow path connected to the upper opening of the tank that has been filled with water in the water filling step, thereby increasing the water pressure inside the tank to a predetermined pressure; and a drainage step of discharging water from the lower opening of the tank after the pressurization step is completed.

[0006] In the draining step, air may be pumped into the upper opening of the tank.

[0007] In the water injection step, the upper valve may be closed when air bubbles contained in the water flowing through the upper flow path are no longer detected.

[0008] The tank may have, for example, a cylindrical body having a larger diameter than the openings at both ends along the central axis, and funnel-shaped shoulder portions provided between each of the openings and the body and having a diameter that decreases toward each of the openings. In the supporting step, the angle between the central axis of the tank and a horizontal plane is within an angular range that allows the tank to move vertically upward as it approaches the upper opening along a path on the inner surface that connects an arbitrary point on the inner surface of the shoulder portion and the upper opening by the shortest distance. [Effects of the Invention]

[0009] According to each of the above aspects of the present disclosure, it is possible to provide a tank inspection method that can efficiently drain water injected into the tank during inspection. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a process flow diagram of an inspection device illustrating an embodiment of a tank inspection method of the present disclosure. [Figure 2] 1 is a flowchart illustrating an embodiment of a tank inspection method of the present disclosure. [Figure 3] 3 is a cross-sectional view showing an example of a tank to be inspected by the inspection method shown in FIG. 2. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, an embodiment of a tank inspection method according to the present disclosure will be described with reference to the drawings.

[0012] Fig. 1 is a process flow diagram of an inspection device 100 illustrating an embodiment of a tank inspection method according to the present disclosure. Fig. 2 is a flowchart illustrating an embodiment of a tank inspection method according to the present disclosure. The tank inspection method TIM of this embodiment primarily inspects tanks T that are, for example, multiple small-diameter high-pressure hydrogen tanks mounted on fuel cell vehicles, but can also inspect general tanks.

[0013] The tank inspection method TIM of this embodiment includes, for example, a supporting step P1, a water injection step P2, a pressure increase step P3, and a drainage step P4 shown in Fig. 2, and can be performed by an inspection device 100 as shown in Fig. 1. The inspection device 100 includes, for example, a water tank 101, a low-pressure pump 102, one or more clamps 103, an air bubble sensor 104, a high-pressure pump 105, and an air supply unit 106.

[0014] The inspection device 100 may, for example, be equipped with a plurality of clamps 103, and by supporting one tank T on each clamp 103, it is possible to simultaneously inspect a plurality of tanks T. Note that the number of clamps 103 equipped in the inspection device 100, i.e., the number of tanks T that can be simultaneously inspected, can be increased or decreased depending on, for example, the performance of the low-pressure pump 102 and the high-pressure pump 105 that pump water to each tank T via the water supply line 111.

[0015] The water tank 101 stores water used for testing the tanks T, for example. The water tank 101 includes, for example, a heater 101h and an agitator 101a, and maintains the temperature of the stored water within a predetermined temperature range. The low-pressure pump 102 is provided, for example, in a water supply line 111 connecting the water tank 101 and the clamp 103, and pumps water to each tank T via the water supply line 111.

[0016] A filter 111f, for example, is provided in the water supply line 111 between the water tank 101 and the low-pressure pump 102. In addition, a pressure gauge 111p, two check valves 111c, a differential pressure type high-pressure flow meter 111h, a water supply valve 111w, and a lower valve 111b, for example, are provided in the water supply line 111 between the low-pressure pump 102 and each of the clamps 103.

[0017] Furthermore, a low-pressure return line 112 branches off from the water supply line 111 between the pressure gauge 111p and the check valve 111c, and a high-pressure return line 113 branches off from the water supply line 111 between the two check valves 111c, each extending to the water tank 101. The low-pressure return line 112 and the high-pressure return line 113 are provided with a low-pressure regulator 112r and a high-pressure regulator 113r, respectively.

[0018] 3 is a cross-sectional view showing an example of a tank T that is an inspection target of the tank inspection method TIM of this embodiment. The tank T has, for example, a generally cylindrical shape, and an opening T1 is provided at each of one end and the other end of the tank T in the longitudinal direction along the central axis Ta of the tank T. Each opening T1 opens, for example, at the tip of a cylindrical neck portion T2 provided at both ends of the tank T in the longitudinal direction.

[0019] A cylindrical nozzle T3 having a thread on the outer periphery is attached to the periphery of each neck portion T2 of the tank T. The tank T also has a cylindrical body portion T4 having a larger diameter than the opening portion T1, and a shoulder portion T5 provided between each opening portion T1 and the body portion T4, as shown in Fig. 1 or 3. The shoulder portion T5 has a funnel-, dome-, or truncated cone-like shape, with its diameter decreasing toward each opening portion T1, as shown in Fig. 3.

[0020] 1, each clamp 103 of the inspection device 100 has, for example, one side connected to a water supply line 111 and the other side connected to an overflow line 114. The clamp 103 supports the tank T by, for example, holding both longitudinal ends of the tank T along the central axis Ta. More specifically, each clamp 103 clamps, for example, the nozzles T3 at both ends of the tank T, and supports the tank T with one opening T1 connected to the water supply line 111 and the other opening T1 connected to the overflow line 114.

[0021] Furthermore, each clamp 103 supports the tank T with the central axis Ta of the cylindrical tank T intersecting the horizontal plane. More specifically, each clamp 103 supports the tank T upright so that the central axis Ta along the longitudinal direction of the tank T is parallel to the vertical direction and perpendicular to the horizontal plane. With the tank T supported by the clamp 103, the opening T1 provided at one end of the tank T and the opening T1 provided at the other end of the tank T become a lower opening T1b located below in the vertical direction and an upper opening T1t located above in the vertical direction, respectively.

[0022] When the tank T is supported by each clamp 103, the central axis Ta of the tank T does not necessarily have to be perpendicular to the horizontal plane. The clamp 103 can support the tank T, for example, so that the central axis Ta of the tank T has an angle within a predetermined range with respect to the horizontal plane. Here, the range of the angle of the central axis Ta of the tank T with respect to the horizontal plane can be set as follows.

[0023] First, as shown in Fig. 3, a path R on the inner surface of the shoulder portion T5 of the tank T is assumed to be the shortest path connecting an arbitrary point P on the inner surface of the upper shoulder portion T5 of the tank T and the upper opening T1t of the tank T. Then, the angle of the central axis Ta of the tank T supported by the clamp 103 relative to the horizontal plane is set within a range that allows it to move vertically upward along this path R as it approaches the upper opening T1t.

[0024] With the tank T supported by each clamp 103, the overflow line 114 connected to the upper opening T1t of each tank T extends, for example, from each clamp 103 to the water tank 101. In the inspection device 100 of this embodiment, the overflow line 114 forms an upper flow path connected to the upper opening T1t of the tank T, and the water supply line 111 forms a lower flow path connected to the lower opening T1b of the tank T.

[0025] The overflow line 114 is provided with, for example, a pressure gauge 114p, an upper valve 114t, an overflow valve 114o, an air bubble sensor 104, and a filter 114f. The air bubble sensor 104 detects, for example, the presence or absence of air bubbles in the water flowing through the overflow line 114. The air bubble sensor 104 may be, for example, a photoelectric, capacitance, or ultrasonic air bubble sensor.

[0026] The high-pressure pump 105 is connected, for example, between the two check valves 111c of the water supply line 111. The high-pressure pump 105 pumps water to the lower openings T1b of each tank T via the water supply line 111, for example, to increase the water pressure inside the tank T to a predetermined pressure. The air supply unit 106 includes, for example, an air compressor, and pumps air into the air supply line 115.

[0027] The air supply line 115 branches into multiple branch lines at branch points between the air supply unit 106 and each clamp 103, for example, and is connected between the upper valve 114t and the overflow valve 114o of the overflow line 114. The air supply line 115 is provided with an air intake valve 115a in each branch line downstream of the branch point. Each air intake valve 115a opens and closes its corresponding branch line of the air supply line 115.

[0028] The inspection device 100 also has a drain line 116 that branches off from between the lower valve 111b and the water supply valve 111w of the water supply line 111 connected to each clamp 103 and extends to the water tank 101. The drain line 116 is provided with, for example, a drain valve 116d and a filter 116f.

[0029] The tank inspection method TIM of this embodiment will be described in detail below.

[0030] As shown in Fig. 2, when the tank inspection method TIM of this embodiment is started, a supporting step P1 is first performed. At the start of this supporting step P1, the water supply valve 111w and the lower valve 111b of the water supply line 111, the upper valve 114t and the overflow valve 114o of the overflow line 114, the air intake valve 115a of the air supply line 115, and the drain valve 116d of the drain line 116 shown in Fig. 1 are closed.

[0031] In the supporting step P1, the tank T is supported by each clamp 103 with the central axis Ta of the cylindrical tank T intersecting the horizontal plane. More specifically, for example, the tank T is supported by each clamp 103 with the tank T standing upright and the central axis Ta of the tank T perpendicular to the horizontal plane. As a result, the openings T1 provided at one end and the other end of the longitudinal direction of the tank T along the central axis Ta of the tank T become a lower opening T1b and an upper opening T1t located on the lower and upper sides in the vertical direction, respectively.

[0032] In the supporting step P1, the angle between the central axis Ta of each tank T and the horizontal plane is, for example, within the above-mentioned predetermined angle range. Here, the predetermined angle range is an angle range within which the tank T can move vertically upward as it approaches the upper opening T1t along a path R on the inner surface of the shoulder portion T5 of the tank T that connects an arbitrary point P on the inner surface of the shoulder portion T5 of the tank T shown in Fig. 3 with the upper opening T1t of the tank T in the shortest distance.

[0033] Next, the water injection step P2 is performed. In the water injection step P2, for example, the water supply valve 111w and the lower valve 111b of the water supply line 111, and the upper valve 114t and the overflow valve 114o of the overflow line 114 shown in FIG. 1 are opened. Furthermore, the low-pressure pump 102 is operated to pump water from the water tank 101 through the filter 111f, the check valve 111c, the high-pressure flow meter 111h, the water supply valve 111w, and the lower valve 111b of the water supply line 111 to the lower opening T1b of each tank T.

[0034] As a result, water is poured into the tank T from the lower opening T1b of each tank T supported in the supporting step P1, and air inside the tank T is discharged from the upper opening T1t of each tank T. In the water pouring step P2, when each tank T is filled with water, the water inside the tank T overflows from the upper opening T1t of the tank T, flows into the overflow line 114, passes through the filter 114f, and returns to the water tank 101.

[0035] In the water injection step P2, the air bubble sensor 104 detects, for example, air bubbles contained in the water flowing through the overflow line 114. When the air bubble sensor 104 no longer detects any air bubbles, the inspection device 100 closes the upper valve 114t of the overflow line 114, which is the upper flow path connected to the upper opening T1t of each tank T. Furthermore, when inspecting multiple tanks T consecutively, the water supply valves 111w and lower valves 111b connected to the other tanks T are closed, except for the water supply valve 111w and lower valve 111b connected to the tank T to be inspected first.

[0036] Thereafter, the low-pressure pump 102 is stopped, and the water injection process P2 ends. The water injection process P2 may be performed simultaneously for multiple tanks T, or may be performed sequentially for each tank T. When the water pressure in the water supply line 111 detected by the pressure gauge 111p exceeds a predetermined pressure, for example, the low-pressure regulator 112r of the low-pressure return line 112 opens, and water is released from the water supply line 111 to the water tank 101 via the low-pressure return line 112.

[0037] Next, the pressurization step P3 is carried out. The pressurization step P3 is started after the water filling step P2 is completed, with the upper valve 114t that opens and closes the overflow line 114, which is the upper flow path connected to the upper opening T1t of the tank T that is full of water, closed. In the pressurization step P3, the high-pressure pump 105 pumps water to the lower opening T1b of each tank T, thereby increasing the water pressure inside the tank T to a predetermined pressure. The pressurization step P3 may be carried out simultaneously for multiple tanks T, or may be carried out sequentially for each tank T.

[0038] When the pressurization step P3 is performed sequentially for each tank T, water is pumped by the high-pressure pump 105 to the lower opening T1b of the tank T to be pressurized first. After the water pressure inside the tank T to be pressurized first is increased to a predetermined pressure, for example, about 105 MPa, the water supply valve 111w and the lower valve 111b connected to that tank T are closed. Thereafter, the water supply valve 111w and the lower valve 111b of the water supply line 111 connected to the tank T to be inspected second are opened.

[0039] Then, water is pumped by the high-pressure pump 105 to the lower opening T1b of the tank T that is to be pressurized second, and the water pressure inside that tank T is increased to a predetermined pressure, and then the water supply valve 111w and the lower valve 111b connected to that tank T are closed. Thereafter, the water pressure inside the other tanks T is increased to predetermined pressures in sequence, and the water supply valves 111w and the lower valves 111b connected to those tanks T are closed. This allows the expensive high-pressure pump 105 to operate continuously, improving operating efficiency.

[0040] Finally, the high-pressure pump 105 is stopped, and the pressurization step P3 ends. When the water pressure inside the tank T detected by the pressure gauge 114p exceeds a predetermined pressure, for example, the high-pressure regulator 113r of the high-pressure return line 113 opens, and water is discharged from the water supply line 111 through the high-pressure return line 113 to the water tank 101.

[0041] Next, the drainage step P4 is carried out. In the drainage step P4, for example, the lower valve 111b of the water supply line 111, which was closed in the pressurization step P3, is opened, and the drainage valve 116d of the drainage line 116 is opened, thereby reducing the water pressure inside each tank T. Furthermore, the overflow valve 114o and the upper valve 114t of the overflow line 114 are opened, and water is discharged from the lower opening T1b of the tank T to the drainage line 116, and air is introduced into the tank T from the upper opening T1t of the tank T. The water discharged into the drainage line 116 passes through the filter 116f and returns to the water tank 101.

[0042] In this drainage step P4, air may be pressure-fed from the air supply unit 106 to the upper opening T1t of the tank T. More specifically, for example, the overflow valve 114o of the overflow line 114 is closed, and each air intake valve 115a of the air supply line 115 is opened, and air is pressure-fed from the air supply unit 106 through the air supply line 115 and the upper valve 114t to the upper opening T1t of each tank T. Thereafter, the tank T is removed from each clamp 103, and the tank inspection method TIM shown in FIG. 2 is completed.

[0043] As described above, the tank inspection method TIM of this embodiment includes a supporting step P1, a water filling step P2, a pressurization step P3, and a draining step P4. In the supporting step P1, the cylindrical tank T is supported so that the central axis Ta intersects the horizontal plane, with the openings T1 provided at both ends of the central axis Ta of the tank T being the upper opening T1t and the lower opening T1b. In the water filling step P2, water is poured into the tank T through the lower opening T1b of the tank T supported in the supporting step P1, and air inside the tank T is discharged through the upper opening T1t. In the pressurization step P3, water is pumped to the lower opening T1b while the upper valve 114t, which opens and closes the overflow line 114, an upper flow path connected to the upper opening T1t of the tank T filled with water in the water filling step P2, is closed, thereby increasing the water pressure inside the tank T to a predetermined pressure. In the draining step P4, water is discharged through the lower opening T1b of the tank T after the pressurization step P3 is completed.

[0044] With this configuration, in the supporting step P1, one of the openings T1 provided at both ends in the longitudinal direction along the central axis Ta of the cylindrical tank T can be an upper opening T1t, and the other can be a lower opening T1b located at a position lower than the upper opening T1t. As a result, in the water pouring step P2, by pouring water into the tank T from the lower opening T1b, air inside the tank T can be efficiently discharged from the upper opening T1t.

[0045] Furthermore, by supporting the cylindrical tank T with the central axis Ta of the tank T intersecting the horizontal plane in the supporting step P1, it is possible to prevent air pockets from forming inside the tank T in the water filling step P2 and to prevent water from remaining inside the tank T in the water draining step P4. Furthermore, by draining the water inside the tank T from the lower opening T1b in the water draining step P4, the water poured into the tank T during inspection can be efficiently drained by the action of gravity.

[0046] Furthermore, according to the tank inspection method TIM of this embodiment, the water injection process P2, the pressurization process P3, and the drainage process P4 can be performed using the same inspection device 100, and the equipment required for each process can be integrated to reduce equipment costs. Furthermore, the water injection nozzle and drainage nozzle can be eliminated, reducing equipment costs and the time required for each process. Furthermore, the time required to transport the tank T between processes can be reduced.

[0047] Furthermore, in the tank inspection method TIM of this embodiment, in the drainage step P4, air is pressurized and sent to the upper opening T1t of the tank T. As a result, the air pressurized and sent into the tank T through the upper opening T1t pushes the water in the tank T out of the lower opening T1b. Therefore, according to the tank inspection method TIM of this embodiment, the water injected into the tank T during inspection can be efficiently discharged.

[0048] Furthermore, in the tank inspection method TIM of this embodiment, in the water filling step P2, the upper valve 114t is closed when air bubbles contained in the water flowing through the overflow line 114, which is the upper flow path, are no longer detected. This makes it possible to completely discharge any air remaining in the tank T in the water filling step P2 and to carry out the pressurization step P3 with the tank T entirely filled with water.

[0049] In the tank inspection method TIM of this embodiment, the tank T to be inspected has a cylindrical body portion T4 whose diameter is larger than that of the openings T1 at both ends along the central axis Ta, and funnel-shaped shoulder portions T5 provided between each opening T1 and the body portion T4 and whose diameter decreases toward each opening T1. In the tank inspection method TIM of this embodiment, in the supporting step P1, the angle between the central axis Ta of the tank T and a horizontal plane is set within a predetermined angular range. As shown in FIG. 3 , this predetermined angular range is an angular range within which the tank T can move vertically upward as it approaches the upper opening T1t along a path R on the inner surface of the shoulder portion T5 that connects an arbitrary point P on the inner surface of the shoulder portion T5 and the upper opening T1t by the shortest distance.

[0050] With this configuration, by supporting the cylindrical tank T with the central axis Ta of the tank T intersecting the horizontal plane at an angle within a predetermined range in the supporting step P1, it is possible to prevent air pockets from forming inside the tank T in the water filling step P2. Similarly, it is possible to prevent water from accumulating on the inner surface of the shoulder portion T5 when discharging water from the tank T in the draining step P4. Therefore, according to the tank inspection method TIM of this embodiment, the water poured into the tank T during inspection can be efficiently discharged.

[0051] As described above, according to this embodiment, it is possible to provide a tank inspection method TIM that can efficiently discharge water injected into the tank T during inspection.

[0052] The above has described in detail an embodiment of the tank inspection method according to the present disclosure using drawings, but the specific configuration is not limited to this embodiment, and even if there are design changes, etc., within the scope that does not deviate from the gist of the present disclosure, they are included in the present disclosure. [Explanation of symbols]

[0053] 114 Overflow line (upper flow path) 114t upper valve P any point P1 Support process P2 Water injection process P3 Pressure increase process P4 Drainage process R pathway T Tank T1 opening T1t Upper opening T1b lower opening T4 Torso T5 Shoulder section Ta center axis How to inspect a TIM tank

Claims

1. a supporting step of supporting the cylindrical tank such that the central axis intersects with a horizontal plane so that openings provided at both ends of the central axis of the tank become an upper opening and a lower opening; a water filling step in which water is poured into the tank from the lower opening of the tank supported in the supporting step, air is discharged from the tank from the upper opening, and the water overflowing from the upper opening flows into a water tank through an overflow line, thereby filling the tank with water; a pressure increasing step of pumping water into the lower opening of the tank filled with water in the water pouring step to increase the water pressure inside the tank to a predetermined pressure; a drainage step of draining water from the lower opening of the tank after the pressurization step is completed, an upper valve and an overflow valve are provided in the overflow line in this order from the upper opening to the water tank; an air supply line, which is branched from the overflow line and through which air is supplied from an air supply unit, is connected to the overflow line between the upper valve and the overflow valve; The air supply line is provided with an air intake valve, In the water pouring step, the upper valve and the overflow valve are opened, and after the water overflowing from the upper opening flows into the water tank through the overflow line, the upper valve is closed. In the pressurization step, the water pressure inside the tank is increased to a predetermined pressure with the upper valve closed, A tank inspection method, characterized in that, in the draining process, the overflow valve is closed, the upper valve and the air intake valve are opened, and air from the air supply line is pressurized and sent to the upper opening of the tank.

2. 2. The tank inspection method according to claim 1, wherein the upper valve is closed when air bubbles contained in the water flowing through the overflow line are no longer detected during the water injection process.

3. The tank has a cylindrical body portion having a larger diameter than the openings at both ends in a direction along the central axis, and funnel-shaped shoulder portions provided between each of the openings and the body portion, the diameter of which decreases as the shoulder portions approach each of the openings, 2. The tank inspection method according to claim 1, wherein in the supporting step, the angle between the central axis of the tank and a horizontal plane is within an angular range that allows the tank to move vertically upward as it approaches the upper opening along a path on the inner surface that connects any point on the inner surface of the shoulder portion and the upper opening in the shortest distance.

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