An automatic internal inspection device for the weld seam of a high-pressure hydrogen storage container

Abstract

This invention relates to the field of inspection of weld seams in high-pressure hydrogen storage container heads. The technical solution is: an automatic internal inspection device for weld seams in high-pressure hydrogen storage container heads, characterized in that: the device includes a mounting base for fixing to a connecting pipe forging, a motor, a phased array probe that can extend into the connecting pipe forging, an ultrasonic detector connected to the phased array probe, and a guide structure for transmitting motor power to drive the phased array probe to move circumferentially within the inner hole of the connecting pipe forging; the guide structure includes a guide plate fixed to the mounting base by fasteners, an annular guide rail disposed on the inner edge of the guide plate, a gear ring disposed on the outer circumferential surface of the guide plate, a gear fixed to the motor shaft and meshing with the gear ring, and a slide table slidably positioned on the guide rail; the motor is fixed on the slide table. This device should be able to perform ultrasonic phased array inspection on butt weld seams of fully multi-layered high-pressure hydrogen storage container heads, and should have the characteristics of high detection sensitivity and convenient operation.

Description

Technical Field

[0001] The invention relates to the field of detection of weld seams of high-pressure hydrogen storage containers, and in particular to an automatic internal detection device for weld seams of high-pressure hydrogen storage containers. Background Art

[0002] The fully multi-layer high-pressure hydrogen storage container is an important equipment for high-pressure hydrogen storage and has been widely used in hydrogen refueling stations. The butt weld and heat-affected zone 4 between the pipe forging 5 and the double-layer hemispherical head 1 are single-layer structures different from other parts of the container (double-layer or multi-layer). Once the defect expands, it may cause the container to rupture, seriously threatening the safety of equipment and personnel, and may even cause catastrophic accidents.

[0003] Since the pipe forging of the multi-layer high-pressure hydrogen storage container has an opening with a narrow inner diameter, this special structure makes it impossible for conventional inspection equipment to enter. Existing X-ray inspection, magnetic particle inspection, penetration inspection and corresponding inspection equipment are difficult to effectively detect defects generated during the manufacturing process and use. Ultrasonic testing has the advantages of easy operation, high resolution, low cost, wide adaptability, and high sensitivity for detecting area defects in thick-walled containers. However, for internal inspection of such narrow openings, ultrasonic testing also has the following difficulties:

[0004] 1) The aperture is small and it is difficult for conventional phased array probes to enter;

[0005] 2) The inner wall is concave with a small radius of curvature, resulting in large energy loss in ultrasonic propagation at the interface;

[0006] 3) The acoustic path from the inner wall of the opening to the heat-affected zone outside the weld exceeds 120 mm, and the commonly used ultrasonic focusing technology is difficult to meet the requirements;

[0007] 4) The welding structure is complex. One side of the area to be inspected is double-layer low-alloy steel (double-layer hemispherical head), and the other side is single-layer austenitic stainless steel (tube forging). It is difficult to judge the waveform, and the welding section is thick. It is difficult to fully cover the inspection thickness range in a single scan.

[0008] 5) The weld is made of austenitic stainless steel with coarse grains and anisotropy, so the sound energy attenuation is large and the scattering is serious.

[0009] Therefore, it is difficult for the existing ultrasonic phased array technology to achieve satisfactory results in the inspection of fixed multi-layer high-pressure hydrogen storage container head butt welds. Summary of the invention

[0010] The purpose of the present invention is to overcome the deficiencies in the above-mentioned background technology and to provide an automatic internal inspection device for the weld of the head of a high-pressure hydrogen storage container. The device should be able to perform ultrasonic phased array inspection on the butt welds of the head of a full-layer high-pressure hydrogen storage container and have the characteristics of high detection sensitivity and easy operation.

[0011] The technical solution of the present invention is:

[0012] An automatic internal inspection device for a weld of a high-pressure hydrogen storage container head, characterized in that the device comprises a mounting seat for fixing on a pipe forging, a motor, a phased array probe that can be inserted into the pipe forging, an ultrasonic detector connected to the phased array probe, and a guide structure for transmitting motor power to drive the phased array probe to move in a circle in the inner hole of the pipe forging;

[0013] The guide structure comprises a guide plate fixed on the mounting seat by fasteners, an annular guide rail arranged on the inner edge of the guide plate, a gear ring arranged on the outer circumference of the guide plate, a gear fixed on the motor shaft and meshing with the gear ring, and a slide table slidably positioned on the guide rail; the motor is fixed on the slide table;

[0014] The phased array probe includes a mounting rod coaxially arranged with the inner ring of the guide plate, a base coaxially fixed to the left end of the mounting rod to extend into the inner hole of the pipe forging, a plurality of array elements fixed on the base, and wires respectively connecting the array elements with the ultrasonic detector; the mounting rod is fixed to the slide table.

[0015] The base is provided with a mounting groove, the array element is fixed in the mounting groove, the sound-transmitting wedge is fixed to the base and covers the array element in the mounting groove, and a protective film is provided on the surface of the array element.

[0016] The phased array probe is fixed on the slide table by a clamping structure; the clamping structure includes a support fixed to the slide table, a sliding rod fixed on the support and arranged perpendicular to the mounting rod, a sliding block that can slide along the sliding rod and is fixed to the mounting rod, and a spring mounted on the sliding rod for pushing the sliding block.

[0017] The base is provided with a buffer piece for protecting the inner hole wall surface of the pipe forging.

[0018] The mounting seat is made of non-metallic material; the mounting seat is provided with an internal thread matched with the pipe forging.

[0019] The beneficial effects of the present invention are:

[0020] The mounting seat of the present invention can be threadedly connected to the pipe forging. The phased array probe is small in size and can be placed in the pipe forging with a narrow opening. The motor is installed on the slide and drives the phased array probe to perform circular motion through the guide structure, thereby realizing automatic internal detection of the weld of the high-pressure hydrogen storage container head. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a main structural schematic diagram of the present invention.

[0022] Figure 2 It is a schematic diagram of the main structure of the phased array probe in the present invention.

[0023] Figure 3 yes Figure 2 Schematic diagram of the right view structure.

[0024] Figure 4 for Figure 3 AA direction schematic diagram in. DETAILED DESCRIPTION

[0025] The present invention will be further described below in conjunction with the accompanying drawings, but the present invention is not limited to the following embodiments.

[0026] like Figure 1 As shown, an automatic internal inspection device for the weld of a high-pressure hydrogen storage container head includes a mounting seat 2, a motor 9, a phased array probe 23, an ultrasonic detector 14, a guide structure, and a clamping structure.

[0027] The mounting seat is used to be fixed on the container pipe forging, and is provided with a mounting hole that matches the outer diameter of the pipe forging, and the mounting hole is provided with an internal thread that matches the external thread of the pipe forging. The mounting seat is made of non-metallic material (such as nylon) to avoid damaging the single-layer pipe forging.

[0028] The guide structure is arranged on the mounting seat. In the guide structure: the guide plate 3 is fixed to the top end surface of the mounting seat by a fastener 6; the guide plate is annular, and its inner ring edge is provided with an annular guide rail (omitted in the figure) arranged along the circumferential direction, and its outer circumferential surface is provided with a gear ring 3.1; the fastener can be a screw 6; the slide 8 can be slidably positioned on the guide rail; the motor is fixed on the slide, and the gear 7 is fixed on the motor shaft and meshes with the gear ring.

[0029] The phased array probe is fixed to the slide by a clamping structure. The phased array probe includes a mounting rod 19, a base 20 and a plurality of array elements 17. The mounting rod is coaxially fixed to the base and vertically passes through the inner ring of the guide plate. The base is provided with a mounting groove 18, the array elements are arranged along the length direction of the base and fixed in the mounting groove, a protective film 24 is provided on the surface of the array element, one end of the wire 13 is connected to the array element and the other end is connected to the ultrasonic detector after passing through the mounting rod, the sound-transmitting wedge 26 is fixed to the base 20 by a screw 22, and the sound-transmitting wedge covers the array element in the mounting groove. The base is also provided with a buffer, which can be an O-ring 21, and an annular groove 25 for installing the O-ring is provided at both ends of the base. The O-ring protrudes from the surface of the base, which can separate the phased array probe from the inner hole wall of the pipe forging to prevent the phased array probe from damaging the inner hole.

[0030] In the phased array probe: an R20 curved sound-transmitting wedge is selected, a 0.1 mm thick protective film is used, the waveform should be a longitudinal wave, the detection frequency is 4 MHz, the array element spacing is 0.8 mm, the array element gap is 0.1 mm, the array element width is 0.7 mm, the array element length is 10 mm, the number of array elements is 128, and the direction control and dynamic focusing of the phased array beam are achieved through 128 array elements.

[0031] In the clamping structure, a support 10 is fixed on a slide table, at least two slide bars 16 are fixed on the support, the slide bars are perpendicular to the phased array probe, a slider 15 is slidably positioned on each slide bar, the slider is also fixed to the mounting rod of the phased array probe, a spring 11 is mounted on the slide bar for pushing the slider, and the slider and the sound-transmitting wedge are respectively arranged on both sides of the phased array probe to ensure that the sound-transmitting wedge can be close to the inner hole wall of the pipe forging under the action of the spring thrust.

[0032] When the motor is working, the gear rolls along the gear ring of the guide plate, driving the slide to make a circular motion. The slide then drives the phased array probe to make a circular motion in the pipe forging, thereby realizing automatic internal inspection of the weld of the high-pressure hydrogen storage container head.

[0033] The method of use of the present invention is:

[0034] Before testing, fill the container with water, using water as a coupling agent for ultrasonic phased array testing;

[0035] Tighten the mounting seat on the pipe forging 5, connect the phased array probe and the ultrasonic detector, insert the phased array probe into the pipe forging, move the front end of the phased array probe to the end of the inner hole of the pipe forging according to the structural size of the container, and then fix the guide plate on the mounting seat through fasteners (the motor, phased array probe, guide structure and clamping structure are integral components);

[0036] Start the ultrasonic detector and adjust the parameters so that the phased array can carry out linear or fan-shaped deflection focusing scanning, and concentrate the focal area on the butt weld of the head; start the motor, drive the phased array probe to make circular motion through the slide, and perform circumferential scanning inside the butt forging.

[0037] During the scanning process, the displayed image on the ultrasonic detector 14 is observed, and the scanning result images obtained by the A scan, B scan, C scan, etc. are analyzed. If a suspected defect is found, the corresponding area is re-inspected;

[0038] After the test is completed, loosen the fasteners, remove the guide plate (motor, phased array probe, guide structure and clamping structure), and finally unscrew the mounting base.

[0039] Through the above method, volume defects, area defects and longitudinal defects in the weld and heat affected zone can be basically detected.

[0040] Finally, it should be noted that the above examples are only specific embodiments of this patent. Obviously, this patent is not limited to the above examples, and there are many variations. All variations that can be directly derived or associated with the content disclosed by ordinary technicians in this field should be considered to be within the scope of protection of this patent.

Claims

1. An automatic internal inspection device for the weld of a high-pressure hydrogen storage container head, characterized in that: The device comprises a mounting base (2) for fixing on a pipe forging, a motor (9), a phased array probe (23) that can be inserted into the pipe forging, an ultrasonic detector (14) connected to the phased array probe, and a guide structure for transmitting motor power to drive the phased array probe to move in a circle in the inner hole of the pipe forging; The guide structure comprises a guide plate (3) fixed to a mounting seat by fasteners, an annular guide rail arranged at the inner edge of the guide plate, a gear ring (3.1) arranged on the outer circumferential surface of the guide plate, a gear (7) fixed to a motor shaft and meshing with the gear ring, and a slide table (8) slidably positioned on the guide rail; the motor is fixed to the slide table; The phased array probe comprises a mounting rod (19) coaxially arranged with the inner ring of the guide plate, a base (20) coaxially fixed to the left end of the mounting rod so as to extend into the inner hole of the pipe forging, a plurality of array elements (17) fixed to the base, and wires (13) respectively connecting the array elements with the ultrasonic detector; the mounting rod is fixed to the slide table; The base is provided with a mounting groove (18), the array element is fixed in the mounting groove, the sound-transmitting wedge (26) is fixed to the base and covers the array element in the mounting groove, and a protective film (24) is provided on the surface of the array element; The phased array probe is fixed on the slide table by a clamping structure; the clamping structure comprises a support (10) fixed to the slide table, a slide bar (16) fixed to the support and arranged perpendicular to the mounting rod, a slider (15) capable of sliding along the slide bar and fixed to the mounting rod, and a spring (11) mounted on the slide bar for pushing the slider; The base is provided with a buffer member for protecting the inner hole wall surface of the pipe forging; The mounting seat is made of non-metallic material; the mounting seat is provided with an internal thread matched with the pipe forging.

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