Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N29/00—Investigating or analysing materials by the use of ultrasonic, sonic or infrasonic waves; Visualisation of the interior of objects by transmitting ultrasonic or sonic waves through the object
  • G01N29/22—Details, e.g. general constructional or apparatus details
  • G01N29/26—Arrangements for orientation or scanning by relative movement of the head and the sensor
  • G01N29/265—Arrangements for orientation or scanning by relative movement of the head and the sensor by moving the sensor relative to a stationary material
• • G—PHYSICS
  • G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
  • G21C—NUCLEAR REACTORS
  • G21C17/00—Monitoring; Testing ; Maintaining
  • G21C17/003—Remote inspection of vessels, e.g. pressure vessels
  • G21C17/013—Inspection vehicles

Definitions

• This disclosure relates to an inspection device, an inspection system, and an inspection method.
• This application claims the benefit of priority to Japanese Patent Application No. 2024-12762, filed January 31, 2024, the contents of which are incorporated herein by reference.
• Pressure vessels used in plants such as nuclear plants or chemical plants are made from ring-shaped metal plates.
• some pressure vessels have a double structure consisting of an inner vessel with a body made of vertically stacked steel plates welded together at the boundary, and an outer vessel surrounding the inner vessel.
• Welded joints, which are the boundaries between welded metal plates, are more susceptible to fracture due to stress concentration than non-welded parts, so inspections of the welded joints of the inner vessel are regularly conducted.
• Inspection of the welded joints of the inner vessel is carried out by remotely operating an inspection device equipped with a sensor and placing it at the inspection location.
• an inspection device equipped with a sensor and placing it at the inspection location.
• a marker is permanently installed at the welded joint of the inner vessel, and the inspection device travels along the surface of the inner vessel using the marker as a guide.
• the inspection device performs ultrasonic flaw detection on the welded joints of the inner vessel while traveling along the surface of the inner vessel.
• a machined track for a rack gear is placed along the welded joint of the inner container.
• the inspection device performs ultrasonic flaw detection on the welded joint of the inner container while traveling along the surface of the inner container.
• Patent Document 1 had the problem that when the inspection device travels horizontally along the welded joint, it is affected by gravity and deviates from the horizontal traveling line along the welded joint. This required control to correct the traveling line of the inspection device, or inspections to be carried out taking into account in advance that the inspection device will deviate from the traveling line.
• Patent Document 2 requires that the rack gear and the pinion gear of the inspection device be mated, making it difficult to install and remove the inspection device by remote control. As a result, workers must install and remove the inspection device, and this inspection device is not suitable for inspecting pressure vessels, which can be subject to high temperatures, high radiation levels, and confined environments.
• the present disclosure therefore aims to provide an inspection device, inspection system, and inspection method that can properly inspect an object to be inspected.
• An inspection device is an inspection device that is placed between an inner container and an outer container in a double container in which both the inner container and the outer container are partially cylindrical.
• the inspection device includes an inspection unit that inspects the inner container, a main body that is provided with wheels for movement, and an arm that has a radial restriction mechanism that restricts radial movement of the double container on the main body.
• the inspection device travels circumferentially around the inner surface of the outer container with one surface of the main body in contact with the vertical upper surface of a guide that extends circumferentially around the outer container.
• the arm may include a first arm extending from the main body toward the inner container, and a second arm connected to the first arm and having the inspection unit movable in the vertical direction.
• the first arm may limit radial movement of the double container in the main body by pressing the second arm against the outer surface of the inner container.
• the first arm may include an elastic body, and the elastic force of the elastic body may be used to remove restrictions on radial movement of the double container in the main body.
• the system may further include a position control mechanism that controls the inspection device to a start position for the inspection, and the position control mechanism may detect an index indicating a reference position provided on the guide and identify the reference position as the position of the inspection device in the double container.
• At least one gap may be provided in the guide extending circumferentially around the outer container, and the gap may be of a length that does not interfere with the circumferential movement of the inspection device.
• An inspection system may include the above-described inspection device, a guide extending circumferentially in the outer container of the double container, and a control device that controls the above-described inspection device.
• An inspection method uses an inspection device for double containers in which both the inner and outer containers are partially cylindrical, the inspection device comprising an inspection unit disposed between the inner and outer containers and inspecting the inner container, a main body provided with wheels for movement, and an arm having a radial restriction mechanism that restricts radial movement of the double container on the main body, and includes the steps of suspending the inspection device and positioning it so that one surface of the main body is in contact with the vertical upper surface of a guide extending circumferentially of the outer container, activating the radial restriction mechanism to restrict radial movement of the double container of the inspection device, driving the wheels to move the inspection device circumferentially around the double container, inspecting the inner container, and stopping the radial restriction mechanism and hoisting the inspection device.
• This disclosure makes it possible to properly inspect the subject.
• FIG. 1 is a perspective view showing a pressure vessel to be inspected.
• FIG. 2 is a diagram showing a schematic relationship between the devices that make up the inspection system.
• FIG. 3 is a perspective view showing the inspection device.
• FIG. 4A is a schematic diagram showing an arm in an inspection device when a radial direction limiting mechanism is not activated.
• FIG. 4B is a schematic diagram showing the arm in the inspection device when the radial direction limiting mechanism is activated.
• FIG. 5A is a perspective view showing a pressure vessel provided with a guide.
• FIG. 5B is a cross-sectional view of a pressure vessel with a guide.
• FIG. 5C is a longitudinal cross-sectional view of a pressure vessel provided with a guide.
• FIG. 6 is a functional block diagram of a control device included in the inspection system.
• FIG. 7 is a flowchart showing the process flow of the inspection method performed by the inspection system.
• FIG. 8 is a perspective view illustrating the configuration of an inspection device according to a modified example.
• the inspection system 100 is a system that includes an inspection device 110 that performs various inspections on a pressure vessel 200 used in a plant such as a nuclear plant or a chemical plant.
• FIG. 1 is a perspective view showing a pressure vessel 200 to be inspected according to the present disclosure.
• the pressure vessel 200 is a double vessel including an inner vessel 210 and an outer vessel 220.
• the inner container 210 is a cylindrical container with a body portion made by stacking annular metal plates 211 vertically and welding their boundaries 212 circumferentially.
• the welded boundaries 212 will be referred to as the weld joints 212.
• the inner container 210 is provided inside the outer container 220. Both the outer container 220 and the inner container 210 are containers having a partially cylindrical shape. A space V is created between the inner container 210 and the outer container 220, which are contained within the outer container 220.
• the outer container 220 also has at least one opening 221 that connects the space V with the outside of the pressure vessel 200. In the present disclosure, four openings 221 are provided, spaced 90 degrees apart around the central axis of the outer container 220.
• the inspection device 110 is placed in the space V from outside the pressure vessel 200 via the opening 221.
• the inspection device 110 performs inspections on the pressure vessel 200 while moving through the space V.
• Specific examples of inspections performed by the inspection device 110 include ultrasonic flaw detection, X-ray transmission inspection, eddy current inspection, penetrant inspection, magnetic particle inspection, and non-destructive inspection such as visual inspection.
• the above-mentioned pressure vessel 200 is a double-walled pressure vessel used in a nuclear power plant, and the inspection system 100 that performs ultrasonic flaw detection on the weld joint 212 of the inner vessel 210 will be described.
• Figure 2 is a diagram explaining the general relationship between the devices that make up the inspection system 100.
• the inspection device 110 is used as the reference, and the perpendicularly intersecting X-axis (radial direction), Y-axis (circumferential direction, circumferential tangential direction), and Z-axis (vertical direction) are defined as shown.
• the inspection system 100 includes the above-mentioned inspection device 110, a guide 120 provided in the pressure vessel 200, a control device 130, and a conveying device 140.
• the guide 120 is a protruding member that protrudes radially inward from the inner surface of the outer container 220.
• the guide 120 extends in the circumferential direction of the outer container 220.
• the guide 120 is provided on the inner surface of the outer container 220 at a position corresponding to the weld joint 212 of the inner container 210.
• the inspection device 110 inspects the inner vessel 210 using, for example, ultrasound.
• the inspection device 110 performs ultrasonic flaw detection on the weld joint 212 of the inner vessel 210.
• the inspection device 110 is provided with at least one wheel on each of its upper and lower vertical surfaces.
• the inspection device 110 is placed in the space V of the pressure vessel 200 with the wheel on the lower vertical surface in contact with the upper vertical surface of the guide 120 and the wheels on both sides parallel to the vertical direction in contact with the inner surface of the outer vessel 220.
• the inspection device 110 performs ultrasonic flaw detection on the weld joint 212 of the inner vessel 210 while moving circumferentially around the inner surface of the outer vessel 220.
• the inspection device 110 is also communicatively connected to the control device 130 (described later) via a cable.
• the transport device 140 places the inspection device 110 in the space V of the pressure vessel 200.
• Each component of the inspection system 100 is described in detail below.
• Figure 3 is a perspective view illustrating the configuration of the inspection device 110 included in the inspection system 100.
• the inspection device 110 includes a main body 111, a first arm 112, a second arm 113, and an inspection unit 114.
• the main body 111 has a rectangular parallelepiped shape.
• the main body 111 is provided with a traveling mechanism 1110 and a position control mechanism 1111.
• the traveling mechanism 1110 is a mechanism that allows the inspection device 110 to travel along the inner surface of the outer container 220.
• the traveling mechanism 1110 includes wheels 1110a.
• the wheels 1110a have a cylindrical shape.
• the wheels 1110a are arranged so that the circular surfaces of the wheels 1110a are parallel to each of the planes (XY planes) of the main body 111 that are parallel to the vertical direction.
• two wheels 1110a are arranged on each of the planes of the main body 111 that are parallel to the vertical direction.
• the vertical upper surface of the main body 111 faces the vertical lower surface of each wheel 1110a.
• the vertical lower surface of the main body 111 faces the vertical upper surface of each wheel 1110a.
• Each of the wheels 1110a arranged on the vertical upper and lower surfaces of the main body 111 may be arranged so that at least a portion of it protrudes radially or circumferentially from the vertical upper and lower surfaces of the main body 111.
• the outer peripheral surfaces of the wheels 1110a provided on the vertical upper and lower surfaces of the main body 111 contact the inner surface of the outer vessel 220 (see Figure 2). Furthermore, the lower vertical surface of the wheels 1110a provided on the vertical lower surface of the main body 111 contacts the upper vertical surface of the guide 120 (see Figure 2).
• the wheel 1110a is driven by a drive device not shown in FIG. 3.
• the drive device that drives the wheel 1110a is, for example, a motor.
• the traveling mechanism 1110 may be composed of wheels 1110a only, or may further include other components.
• other components include a damper or a brake device.
• a damper absorbs vibrations that occur in the wheels 1110a in response to the undulations of the inner surface of the outer container 220.
• a brake device applies a braking force to the wheels 1110a to stop the traveling of the inspection device 110.
• the position control mechanism 1111 is a mechanism for controlling the movement of the inspection device 110 to the inspection start position.
• the position control mechanism 1111 identifies the position of the inspection device 110 based on a reference position linked to the position information in the pressure vessel 200.
• the position control mechanism 1111 then controls the movement of the inspection device 110 to the inspection start position. For this reason, the position control mechanism 1111 has a reference position detection sensor.
• the reference position detection sensor is a sensor that detects an index 123 indicating a reference position provided on the guide 120, which will be described later.
• the type of reference position detection sensor is determined appropriately depending on the index 123 provided on the guide 120.
• a notch is provided on the vertical upper surface of the guide 120 as the index 123 indicating the reference position.
• the index 123 is not limited to a notch.
• Another example of the index 123 is a protrusion that protrudes vertically upward from the vertical upper surface of the guide 120.
• the distance between the main body 111 and the position on the vertical upper surface of the guide 120 where the index 123 is provided differs from the distance between the main body 111 and the position on the vertical upper surface of the guide 120 where the index 123 is not provided. Therefore, in the present disclosure, a distance detection sensor that detects the distance between the main body and the vertical upper surface of the guide 120 is used as the reference position detection sensor.
• the distance detection sensor may be an eddy current distance detection sensor or an optical distance detection sensor.
• the reference position detection sensor may detect the reference position using a mechanical switch.
• the position control mechanism 1111 determines whether or not the indicator 123 is present based on the distance between the main body 111 and the vertical upper surface of the guide 120 detected by the reference position detection sensor. For example, if the distance between the main body 111 and the vertical upper surface of the guide 120 has changed by more than a predetermined value compared to the previously detected distance, the position control mechanism 1111 determines that the indicator 123 is located at the position where the distance has changed by more than the predetermined value. The position control mechanism 1111 sets the position determined to be where the indicator 123 is located as the reference position, and controls the movement of the inspection device 110 to the inspection start position using the reference position as the starting point.
• the first arm 112 has a first support pillar 1120, a radial limiting mechanism 1121, and an actuator 1122.
• the first support pillar 1120 is provided on one end side.
• the radial limiting mechanism 1121 is provided on the other end side.
• the actuator 1122 activates the radial limiting mechanism 1121.
• the radial limiting mechanism 1121 is connected to the second arm 113, which will be described later.
• the radial limiting mechanism 1121 has a pantograph-type configuration.
• the radial limiting mechanism 1121 which has a pantograph-type configuration, will be described below.
• the radial restriction mechanism 1121 has a pantograph 1121a consisting of pantograph arms that intersect in the XY plane or the XZ plane.
• the radial restriction mechanism 1121 is composed of two pantographs 1121a with pantograph arms that intersect in the XY plane.
• the end of each pantograph 1121a facing the outer container 220 is connected to the first support 1120 via a base 1121b.
• the end of each pantograph 1121a facing the inner container 210 is connected to the second arm 113 via a support base 1121c.
• the actuator 1122 activates the radial restriction mechanism 1121.
• the actuator 1122 is provided inside the first support 1120 of the first arm 112.
• the actuator 1122 shortens the distance between one end of each pantograph arm at the end of each pantograph 1121a on the outer surface side of the outer container 220. This causes the pantograph 1121a to extend radially, and the first arm 112 to extend radially.
• the extension of the first arm 112 will be described in detail later using a different drawing.
• the second arm 113 has a second support 1130 and a ball plunger 1131.
• the second arm 113 has ball plungers 1131 provided on both ends of the second support 1130.
• the second arm 113 is arranged so that the longitudinal direction of the second support 1130 is vertical. That is, the second support 1130 is arranged so that its longitudinal direction is positioned perpendicular to the weld joint 212 of the inner vessel 210 in the space V of the pressure vessel 200 (see Figure 2).
• the second support 1130 is connected to the other end of the first arm 112 near its middle portion.
• the inspection unit 114 described below, is provided on the second support 1130 so that it is movable along the second support 1130.
• the second support 1130 is provided with a slide mechanism. By operating the slide mechanism, the inspection unit 114 is moved (scanned) vertically along the length of the second support column 1130 from one end to the other.
• Ball plunger 1131 has a spring (not shown) and ball 1131a inside the body.
• the spring and ball 1131a are arranged in this order, starting from the end of ball plunger 1131 on the second support post 1130 side.
• Ball 1131a is rotatably mounted. Furthermore, ball 1131a may be mounted so that a portion thereof protrudes radially inward.
• Figures 4A and 4B are diagrams showing the operation of an arm including a radial limiting mechanism 1121 having a pantograph-type configuration.
• Figures 4A and 4B are also simplified diagrams of the inspection device 110 in Figure 2, viewed from vertically above.
• Figure 4A is a schematic diagram showing the arm when the radial limiting mechanism 1121 is not activated.
• Figure 4B is a schematic diagram showing the arm when the radial limiting mechanism 1121 is activated.
• the first arm 112 When the radial limiting mechanism 1121 is not activated, the first arm 112 is in a state in which the pantograph 1121a is not extended, as shown in Figure 4A.
• the elastic body 1121d provided between the base 1121b and the support base 1121c prevents the pantograph 1121a from contracting more than necessary when the radial limiting mechanism 1121 is not activated.
• the device length ML which is the length from the inner surface of the outer container 220 to the end of the ball plunger 1131 on the inner container 210 side, is shorter than the distance D from the inner surface of the outer container 220 to the outer surface of the inner container 210. Therefore, the inspection device 110 can move radially within the space V of the pressure vessel 200.
• the device length ML is preferably shorter than the distance from the radial inner surface of the guide 120 to the outer surface of the inner container 210. This allows the inspection device 110 to pass between the guide 120 and the outer surface of the inner container 210. As a result, the inspection device 110 can freely move vertically from the vertical lower surface to the upper surface of the outer container 220 in the space V of the pressure vessel 200.
• the inspection device 110 can move vertically and radially within the space V of the pressure vessel 200.
• the actuator 1122 extends the pantograph 1121a radially inward.
• the ball 1131a of the ball plunger 1131 of the second arm 113 is pressed against the outer surface of the inner container 210.
• the device length ML is equal to the distance D from the inner surface of the outer container 220 to the outer surface of the inner container 210.
• the inspection device 110 When the radial restriction mechanism 1121 is activated and the device length ML matches the distance D, the inspection device 110 is in a tensioned state between the outer surface of the inner container 210 and the inner surface of the outer container 220. This positional relationship restricts the radial movement of the pressure vessel 200 in the inspection device 110, particularly the radially inward movement of the inspection device 110. Meanwhile, the inspection device 110 can move circumferentially by rolling the wheel 1110a and the ball 1131a of the ball plunger 1131.
• the actuator 1122 stops operating, and an elastic force acts in the direction of contraction of the elastic body 1121d, thereby releasing the restriction on the radially inward movement of the inspection device 110. Therefore, even if the inspection device 110 loses power due to a malfunction or other reason, the restriction on the radial movement of the inspection device 110 is released, allowing the inspection device 110 to be retrieved from the space V of the pressure vessel 200.
• the inspection device 110 can freely move vertically from the vertical lower surface to the upper surface of the outer container 220 in the space V of the pressure vessel 200. This allows the inspection device 110 to move freely vertically from the guide 120 in which it is currently located to another guide 120 located vertically above or below it in the pressure vessel 200 by releasing the radial restriction mechanism 1121.
• the inspection unit 114 inspects the inner container 210 as the inspection target.
• the inspection unit 114 is an ultrasonic sensor for performing ultrasonic flaw detection inspection on the weld joint 212 of the inner container 210.
• the inspection unit 114 transmits ultrasonic waves to the weld joint 212 and receives the ultrasonic waves reflected by the weld joint 212.
• the inspection system 100 analyzes the ultrasonic waves received by the inspection unit 114 to inspect whether or not defects such as scratches have occurred in the weld joint 212.
• the inspection unit 114 includes a transmitting unit and a receiving unit.
• the transmitting unit has a vibrator that transmits ultrasonic waves.
• the receiving unit has a vibrator that receives ultrasonic waves.
• the inspection unit 114 scans the second arm 113 in the vertical direction within a range from one end to the other longitudinal end of the second support 1130. This allows the inspection unit 114 to inspect a wide area near the weld joint 212, which is the inspection target
• the inspection unit 114 is provided with a separate ultrasonic transmitter and ultrasonic receiver, this is not limiting.
• the inspection unit 114 may also be provided with an ultrasonic transmitter/receiver unit in which the ultrasonic transmitter and ultrasonic receiver are integrated.
• the inspection unit 114 in this disclosure is exemplified as an ultrasonic sensor having a vibrator and a transmitter and receiver, it is not limited to this.
• the inspection unit 114 may also be an ultrasonic sensor that combines a magnet and a coil that can electromagnetically transmit and receive ultrasonic waves.
• Figure 5A is a perspective view showing the pressure vessel 200 equipped with the guide 120.
• Figure 5B is a horizontal cross-sectional view of Figure 5A.
• Figure 5C is a portion of the vertical cross-sectional view of Figure 5A.
• the guide 120 extends circumferentially on the inner surface of the outer container 220.
• the guide 120 extends along the weld joint 212 of the inner container 210.
• the inspection device 110 is placed in the space V of the pressure vessel 200, the upper surface of the guide 120 contacts the vertical lower surface of the wheel 1110a located on the vertical lower surface of the inspection device 110 shown in FIG. 3.
• the inspection device 110 is pressed against the upper surface of the guide 120 by gravity. This restricts the vertically downward movement of the inspection device 110.
• the inspection device 110 travels on the inner surface of the outer container 220, it is not affected by gravity and can travel horizontally along the weld joint 212.
• the vertically upward movement of the inspection device 110 shown in FIG. 3 is not restricted. This allows the inspection device 110 to be easily removed by moving it to the opening 221 when the inspection is completed or if a malfunction occurs with the inspection device 110.
• the inspection device 110 is positioned in the space V of the pressure vessel 200 so that the weld joint 212 is located near the middle of the second support 1130 of the second arm 113. Therefore, the guide 120, which contacts the vertical lower surface of the wheel 1110a located on the vertical lower surface of the inspection device 110, is located below the weld joint 212 that the inspection device 110 inspects while traveling.
• the guide 120 is located, for example, vertically below the weld joint 212 by about half the vertical width of the main body 111.
• the weld joint 212 is located within the scanning range of the inspection unit 114 of the inspection device 110 while traveling.
• the inspection device 110 can inspect the weld joint 212 over a wide vertical width. Furthermore, problems such as the ball plunger 1131 coming into contact with the weld joint 212 do not occur.
• the material constituting the guide 120 is determined appropriately depending on the environment of space V.
• the pressure vessel 200 is a double-vessel vessel used in a nuclear power plant, and therefore the environment of space V is a high-temperature, high-radiation environment. Therefore, the guide 120 is preferably made of a metal such as iron, lead, or stainless steel.
• a metal guide 120 thermally expands when exposed to the high-temperature environment of space V. Therefore, in the inspection system 100 according to the present disclosure, the guide 120 is provided with at least one gap 121, as shown in Figures 5A and 5B.
• the gap 121 absorbs the thermal expansion of the guide 120. Therefore, deformation of the guide 120 due to thermal expansion is suppressed.
• the gap 121 has a length L that does not interfere with the circumferential movement of the outer vessel 220 of the inspection device 110 shown in Figure 3.
• the length L of the gap 121 is shorter than the diameter of the wheels 1110a of the inspection device 110. This prevents the wheel 1110a from getting stuck in the gap 121 and becoming unable to move, even when the guide 120 is not thermally expanded.
• the guide 120 is not completely fixed to the inner surface of the outer container 220.
• the surface of the guide 120 that comes into contact with the inner surface of the outer container 220 has a recessed portion 122 that corresponds to a pin 222 protruding from the inner surface of the outer container 220.
• the guide 120 is attached to the inner surface of the outer container 220 by hooking the recessed portion 122 onto the pin 222. Because the guide 120 is not completely fixed to the inner surface of the outer container 220, it is able to tolerate slight deformation due to thermal expansion. This allows the guide 120 to be less susceptible to deformation due to thermal expansion than if it were completely fixed to the inner surface of the outer container 220. Furthermore, even if the guide 120 is deformed or damaged due to thermal expansion, it can be easily replaced.
• the guide 120 is provided with an indicator 123 that indicates a reference position (a reference position for identifying the position of the inspection device 110).
• the indicator 123 is a notch. The notch as indicator 123 is different from the gap 121 described above.
• the control device 130 controls the inspection device 110.
• the control device 130 controls at least the travel of the inspection device 110.
• the control device 130 is located outside the pressure vessel 200.
• the control device 130 is connected to the inspection device 110 via a cable and is therefore located in a shielded room provided near the opening 221 of the pressure vessel 200.
• Figure 6 is a functional block diagram of the control device 130 included in the inspection system 100. In Figure 6, dashed arrows indicate the flow of signals.
• the control device 130 includes a control unit 131, a communication unit 132, a display unit 133, and a memory unit 134.
• the control unit 131 is composed of a semiconductor integrated circuit including a CPU (Central Processing Unit).
• the control unit 131 reads programs and parameters for operating the CPU from ROM (Read-Only Memory).
• the control unit 131 also works as a work area in cooperation with RAM (Random Access Memory) and other electronic circuits to manage and control the entire inspection device 110.
• the control unit 131 includes a travel control unit 1310, an arm extension/retraction control unit 1311, an origin return control unit 1312, a scanning unit 1313, an abnormality determination unit 1314, and a position information acquisition unit 1315.
• the travel control unit 1310 controls the travel mechanism 1110 to control the travel of the inspection device 110.
• the travel control unit 1310 can control the rotation and stopping of the wheels 1110a, as well as the rotation direction of the wheels 1110a, by controlling the drive device of the wheels 1110a. This allows the inspection device 110 to move forward or stop in any circumferential direction on the inner surface of the outer container 220.
• the arm extension/retraction control unit 1311 controls the extension and retraction of the arm of the inspection device 110.
• the arm extension/retraction control unit 1311 controls the extension and retraction of the pantograph 1121a by controlling the actuator 1122 in the radial direction limiting mechanism 1121 of the first arm 112.
• the origin return control unit 1312 controls the movement of the inspection device 110 so that it moves to the inspection start position (origin). For example, the origin return control unit 1312 controls the travel mechanism 1110 to travel the inspection device 110, while the reference position detection sensor of the position control mechanism 1111 detects the index 123, which indicates the reference position provided on the guide 120. The origin return control unit 1312 identifies the position of the inspection device 110 in the pressure vessel 200 based on the position information linked to the position (reference position) where the index 123 is detected, and then controls the movement of the inspection device 110 to the inspection start position.
• the scanning unit 1313 scans the inspection unit 114 in the vertical direction.
• the scanning unit 1313 scans the inspection unit 114 in the vertical direction by operating a slide mechanism provided on the second support 1130. More specifically, the scanning unit 1313 scans the inspection unit 114 in the vertical direction along the length of the second support 1130, in a range from one end to the other end.
• the abnormality determination unit 1314 determines whether or not there is an abnormality in the object to be inspected.
• an abnormality is a defect such as a scratch or breakage.
• the abnormality determination unit 1314 receives the inspection results from the inspection unit 114 and determines whether or not there is an abnormality in the object to be inspected based on the inspection results.
• the inspection unit 114 performs an ultrasonic flaw detection inspection on the weld joint 212 of the inner container 210.
• the abnormality determination unit 1314 acquires information indicating the ultrasonic waves received by the receiving unit of the inspection unit 114 as the inspection result.
• the abnormality determination unit 1314 determines whether or not there is an abnormality, such as a scratch, in the weld joint 212 based on the information indicating the acquired ultrasonic waves.
• the position information acquisition unit 1315 acquires position information of the inspection device 110 within the pressure vessel 200.
• the inspection device 110 is provided with an encoder for detecting the amount of movement of the inspection device 110.
• the position information acquisition unit 1315 acquires information indicating the amount of movement of the inspection device 110 from the inspection start position from the encoder, and acquires position information of the inspection device 110 within the pressure vessel 200.
• the position information acquisition unit 1315 may also acquire position information of the inspection unit 114 on the second support 1130.
• an encoder for detecting the amount of movement of the inspection unit 114 is provided on the second arm 113.
• the position information acquisition unit 1315 acquires position information of the inspection unit 114 on the second support 1130 based on information indicating the amount of movement of the inspection unit 114 acquired from the encoder.
• the communication unit 132 communicates with the inspection device 110 via a cable. For example, the communication unit 132 transmits signals to control each component of the inspection device 110. The communication unit 132 also receives inspection results from the inspection device 110.
• the display unit 133 displays various information. For example, it displays the location information of the inspection device 110 acquired by the location information acquisition unit 1315, the inspection results received from the inspection unit 114, and the presence or absence of abnormalities in the inspection object.
• the storage unit 134 is composed of ROM, RAM, flash memory, HDD, etc.
• the storage unit 134 stores programs and various data used by the control unit 131. For example, the storage unit 134 stores in advance the position information of the index 123 indicating the reference position, the inspection results when normal, etc.
• the storage unit 134 also stores the inspection results received from the inspection unit 114.
• the transporting device 140 shown in Figure 2 is a device that transports the inspection device 110.
• the transporting device 140 transports the inspection device 110 from outside the pressure vessel 200 to space V through the opening 221 of the outer vessel 220. More specifically, the transporting device 140 transports the inspection device 110 from outside the pressure vessel 200 to the opening 221 of the outer vessel 220.
• the transporting device 140 suspends the inspection device 110 from the opening 221 using a cable or dedicated wire that connects the inspection device 110 and the control device 130.
• the transporting device 140 suspends the inspection device 110 vertically downward in space V and places it on the vertical upper surface of the desired guide 120.
• the transporting device 140 also suspends the inspection device 110 located on the vertical upper surface of the guide 120 up to the opening 221 by reeling in the cable that connects the inspection device 110 and the control device 130.
• the transport device 140 transports the inspection device 110 from the opening 221 to the outside of the pressure vessel 200.
• a telescopic manipulator is used as the transport device 140.
• the telescopic manipulator transports the inspection device 110 between the outside of the pressure vessel 200 and the opening 221 by extending and retracting.
• FIG. 7 is a flowchart showing the processing flow of the inspection method performed by the inspection system 100.
• the inspection method includes an installation process S100, a radial direction restriction process S101, a return to origin process S102, an inspection process S103, an abnormality determination process S104, a notification process S105, an end determination process S106, a movement process S107, and a recovery process S108. Each process will be described below.
• the transporting device 140 performs the installation process S100, which involves inserting the inspection device 110 into the space V of the pressure vessel 200 and placing it on the desired guide 120.
• the transporting device 140 transports the inspection device 110 to the opening 221. Then, using a cable or dedicated wire connecting the inspection device 110 and the control device 130, the transporting device 140 suspends the inspection device 110 from the opening 221 and places it in contact with the vertical upper surface of the guide 120.
• the arm extension/retraction control unit 1311 executes a radial restriction process S101 that restricts the radial movement of the inspection device 110 placed on the guide 120.
• the arm extension/retraction control unit 1311 controls the radial restriction mechanism 1121 to place the inspection device 110 in a tensioned state between the outer surface of the inner container 210 and the inner surface of the outer container 220. This makes it possible to restrict the radial movement of the inspection device 110, particularly the radially inward movement of the inspection device 110. As a result, it is possible to prevent the inspection device 110 from falling off the guide 120.
• the origin return control unit 1312 executes origin return processing S102, which controls the movement of the inspection device 110 to the inspection start position.
• origin return processing S102 the origin return control unit 1312 controls the travel mechanism 1110 to cause the inspection device 110 to travel in the circumferential direction.
• the origin return control unit 1312 also detects the index 123, which indicates the reference position provided on the guide 120, using the reference position detection sensor of the position control mechanism 1111.
• the origin return control unit 1312 identifies the position of the inspection device 110 in the pressure vessel 200 based on position information linked to the position (reference position) where the index 123 is detected, and then controls the movement of the inspection device 110 to the inspection start position.
• the control unit 131 executes the inspection process S103 to inspect the inspection object.
• the control unit 131 controls the transmission unit of the inspection unit 114 to transmit ultrasonic waves from the transmission unit toward the weld joint 212.
• the reception unit of the inspection unit 114 receives the ultrasonic waves reflected by the weld joint 212.
• the scanning unit 1313 of the control unit 131 also controls the sliding mechanism of the second support 1130 to move the inspection unit 114 vertically. In the inspection process S103, this series of operations, which involves transmitting and receiving ultrasonic waves in the inspection unit 114 and moving the inspection unit 114 vertically, is repeated across the entire vertical width of the weld joint 212.
• the inspection unit 114 transmits the inspection results to the abnormality determination unit 1314.
• the inspection unit 114 may transmit the inspection results to the abnormality determination unit 1314 each time a series of operations involving the transmission and reception of ultrasonic waves to and from the welded joint 212 and the vertical movement of the inspection unit 114 is completed.
• the inspection unit 114 may transmit the inspection results to the abnormality determination unit 1314 all at once after a series of operations involving the transmission and reception of ultrasonic waves to and from the welded joint 212 and the vertical movement of the inspection unit 114 has been repeated across the entire vertical width of the welded joint 212.
• the inspection unit 114 may transmit the inspection results to the abnormality determination unit 1314 at an appropriate time when ultrasonic waves are transmitted and received to and from the welded joint 212 or when the inspection unit 114 is moving vertically.
• the abnormality determination unit 1314 executes abnormality determination processing S104, which determines whether or not an abnormality exists in the test object based on the test results received from the inspection unit 114.
• the abnormality determination unit 1314 determines whether or not an abnormality exists in the test object by comparing the test results received from the inspection unit with normal test results pre-stored in the memory unit 134. If the abnormality determination unit 1314 determines that an abnormality exists in the test object (YES in S104), processing proceeds to notification processing S105. On the other hand, if it determines that no abnormality exists in the test results (NO in S104), processing proceeds to termination determination processing S106.
• the abnormality determination unit 1314 determines whether or not an abnormality exists in the test results based on a comparison with the test results under normal conditions, but this is not limited to this.
• the abnormality determination unit 1314 may determine that an abnormality exists in the test object when the test results received from the test unit 114 indicate an abnormal value.
• the abnormality determination unit 1314 determines whether or not there is an abnormality in the inspection object based on the inspection results received from the inspection unit 114, but this is not limiting.
• a person may determine whether or not there is an abnormality in the inspection object based on the inspection results received from the inspection unit 114.
• specific examples of people who determine whether or not there is an abnormality in the inspection object include workers, managers of the pressure vessel 200, etc.
• control unit 131 determines that the inspection object has an abnormality (YES in S104), it executes notification processing S105 to notify the operator or the manager of the pressure vessel 200 of this fact.
• notification processing S105 the control unit 131 displays on the display unit 133 a display image indicating that the inspection object has been determined to have an abnormality.
• control unit 131 may identify the position in the inspection object where it has been determined that there is an abnormality.
• the control unit 131 uses an encoder to identify the position in the inspection object where it has been determined that there is an abnormality.
• the control device 130 identifies the position in the inspection object where it has been determined that there is an abnormality by combining information indicating the amount of movement from the inspection start position detected by the encoder to the position where the inspection result indicating that there is an abnormality was obtained, with position information of the inspection start position pre-stored in the memory unit 134.
• the control unit 131 may notify the worker or the manager of the pressure vessel 200 of the position information of the position where it has been determined that there is an abnormality, along with the fact that it has been determined that there is an abnormality in the inspection object. This also allows the worker or the manager of the pressure vessel 200 to know the position where it has been determined that there is an abnormality.
• the control unit 131 stores the position information of the position in the inspection object where it has been determined that there is an abnormality in the memory unit 134, in association with the inspection result or inspection time that originally made the determination.
• control unit 131 executes the end determination process S106 to determine whether or not the inspection of the specified inspection range has been completed. As a result, if it is determined that the inspection of the inspection range has not been completed (NO in S106), the process proceeds to the transfer process S107. On the other hand, if it is determined that the inspection of the inspection range has been completed (YES in S106), the process proceeds to the collection process S108.
• the travel control unit 1310 determines that inspection of the inspection range has not been completed (NO in S106), it executes movement process S107, which moves the inspection device 110 in the circumferential direction.
• movement process S107 the travel control unit 1310 controls the travel mechanism 1110 to move the inspection device 110 from the first position where inspection process S103 was executed to a second position.
• the second position is a position different from the first position, and is a position moved from the first position in the circumferential direction of the pressure vessel 200. Then, processing returns to inspection process S103.
• the arm extension/retraction control unit 1311 and the transporting device 140 determine that inspection of the inspection range has been completed (YES in S106), they execute the recovery process S108 to recover the inspection device 110 from the pressure vessel 200.
• the arm extension/retraction control unit 1311 stops the operation of the radial direction limiting mechanism 1121 and releases the restriction on the radial movement of the inspection device 110.
• the transporting device 140 lifts the inspection device 110 up to the opening 221 by winding up the cable or dedicated wire connecting the inspection device 110 and the control device 130, and recovers the inspection device 110 from the opening 221. This completes the inspection method process.
• the inspection system 100 includes an inspection device 110.
• the inspection device 110 inspects the weld joint 212 of the inner container 210 while traveling along the inner surface of the outer container 220 in contact with the vertical upper surface of a guide 120 extending along the inner surface of the outer container 220.
• the inspection device 110 is configured to inspect the weld joint 212 of the inner vessel 210 while traveling along the inner surface of the outer vessel 220 while in contact with the vertical upper surface of a guide 120 provided on the inner surface of the outer vessel 220.
• the inspection device 110 is not in a fixed relationship with the guide 120, and can be easily positioned in the pressure vessel 200 by remote control.
• the inspection device 110 can travel horizontally along the weld joint 212 without being affected by gravity.
• FIG. 8 is a perspective view illustrating the configuration of the inspection device 110a.
• components that have the same functions as those described in the inspection device 110 above will be denoted by the same reference numerals, and their descriptions will not be repeated.
• the inspection device 110a differs from the inspection device 110 in that a plate-like member 1110b is provided on the wheel 1110a.
• the plate-like member 1110b is provided on the vertical underside of the wheel 1110a, which is provided on the vertical underside of the main body 111.
• the length of the plate-like member 1110b is not interfere with the circumferential movement of the pressure vessel 200 in the inspection device 110a.
• the length of the plate-like member 1110b is longer than the length L of the gap 121.
• This disclosure can contribute, for example, to Sustainable Development Goal (SDG) Goal 7: “Ensure access to affordable, reliable, sustainable and modern energy” and Goal 13: “Take urgent action to combat climate change and its impacts.”
• SDG Sustainable Development Goal
• Inspection system 110 Inspection device 111: Main body 112: First arm (arm) 1121: Radial restriction mechanism 113: Second arm (arm) 114: Inspection unit 120: Guide 121: Gap 122: Recessed portion 123: Index 130: Control device 131: Control unit 200: Pressure vessel

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  • 2024-11-18 WO PCT/JP2024/040829 patent/WO2025164042A1/ja active Pending
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