Patent Application
20240337344
The invention belongs to the field of NDT, specifically, an NDT device for pipeline.
As the integrity of pipeline is essential to safety in oil & gas transportation and therefore highly concerned by pipeline employer, and poor integrity of pipeline caused by corrosion to pipeline or oil stealing by punching holes on the pipeline will result in a significant economic loss and severe environmental and social impact, it is necessary to test the pipeline regularly, to find out such failure as corrosion, deformation, and leakage in the pipeline, thereby safeguarding the reliable operation of the pipeline.
Currently, methods such as magnetic flux leakage testing and ultrasonic testing are widely used to detect pipeline defects, which have become an important pre-control means to ensure the safe transportation of oil and gas pipelines and are of great significance in eliminating risk factors from said pipelines. With better qualitative and quantitative analysis capability of the defects, the above testing method can effectively evaluate the operating state of the pipeline, and indirectly reduce the incidence of pipeline accidents, thus avoiding heavy losses to the national economy and heavy casualties. However, instruments available for magnetic flux leakage testing feature a heavy load, a certain requirement on flow rate, flow velocity and pressure of the medium, more stringent requirements on the cleanliness of pipeline (pigging needed for many times before commencement of testing) and poor flexibility of equipment in the pipeline because of a greater length (3-4 sections needed). The couplant is required for ultrasonic testing, featuring a lower testing speed and therefore a longer time for testing, also with a certain near-field blind area. To overcome aforesaid problems of large equipment size, poor flexibility of equipment in pipeline, more stringent requirements on cleanliness inside the pipeline and low testing efficiency in said testing methods above, eddy current testing applicable to the conductive pipeline testing is put forward.
Eddy current testing is now an effective method for quantitative nondestructive assessment of surface/sub-surface defects of pipeline structures. It features a rapid non-contact testing process with a higher capability to test surface/sub-surface defects, has become an important pre-control means to ensure the safe transportation of oil and gas pipelines, and is of great significance in eliminating risk factors from said pipelines.
As for the invention, the testing probe generally comprises an excitation coil and an induction coil (the testing coil). An eddy current field is formed via induction on the surface of a tested piece (tested specimen) under the effect of a varying magnetic field produced by the excitation coil. The size and shape of said eddy current field depend on the degree of excitation, parameters of the coil, materials of tested specimen, etc. When the testing probe detects the defect, the original eddy current goes around the defect, which disturbs the eddy current and further affects the magnetic field generated by the eddy current. The defects can be qualitatively and quantitatively analyzed by detecting the change in the magnetic field with the testing coil or a magnetic sensor and extracting the phase and amplitude of a testing signal. The sensitivity and the lift-off height of the eddy current testing probe have always been a hotspot in the eddy current testing field, and the coupling degree between the excitation coil and the testing coil is an important factor affecting the sensitivity and the lift-off height of the testing probe. Therefore, an urgent technical problem to be solved at present is how to improve the coupling degree between the excitation coil and the testing coil.
The invention discloses an NDT device for pipeline, to effectively overcome the problem of lower sensitivity and smaller lift-off height of testing probe because of a poor degree of coupling between the excitation coil and receiving coil of the existing eddy current testing probe.
To realize the purpose of the invention, the invention discloses an NDT device for pipeline, comprising:
A mobile carrier, mainly used to carry and install the probe testing assembly, wherein the mobile carrier can be of a direct tubular structure, or, with other structures arranged on the mobile carrier, the mobile carrier can move with fluid in pipeline or be moved by an actuator.
A probe testing assembly, including a testing component installed on the mobile carrier with a testing element, wherein the testing component is of an integrated structure with the testing element (one or more testing elements on the testing component, i.e. no restriction on quantity of said testing element); once the NDT device for pipeline is placed inside the pipeline, the testing element encapsulating testing probe is close to the inner pipe wall, the testing probe is mainly used to detect any defects on the inner pipe wall, the probe testing assembly can be composed of only one testing component, or jointly of multiple testing components, and accordingly, one or more probe testing assemblies can be available.
The NDT device for pipeline is also provided with a data processing unit, a first signal conditioning unit and a second signal conditioning unit, wherein the testing probe comprises an excitation coil, a receiving coil and a passive resonance coil between the excitation coil and the receiving coil;
The data processing unit is used to generate an excitation signal; the data processing unit, the first signal conditioning unit and the excitation coil are connected in sequence; and the receiving coil, the second signal conditioning unit, and the data processing unit are connected in sequence.
Further, said mobile carrier comprises a cylindrical capsule and a sealing rubber cup, mainly of a mobile carrier structure that can move with fluid in the pipeline, wherein the cylindrical capsule is used for bearing and installation of probe testing assembly and sealing rubber cup; the sealing rubber cup that is made of elastic materials is in a shape of cup when NDT device for pipeline is placed into the pipeline, and edge of the sealing rubber cup can be tightly propped against the inner pipe wall when the edge of the sealing rubber cup is in contact with the inner pipe wall; the sealing rubber cup is used to divide the inside of the pipe into front and rear chambers, and by virtue of a difference in hydraulic pressure between the front and rear chambers of the sealing rubber cup, the NDT device for pipeline can move inside the pipeline; both the sealing rubber cup and the probe testing assembly are installed on the cylindrical capsule; upon installation of the sealing rubber cup and the probe testing assembly, both the center of the sealing rubber cup and the center of the probe testing assembly are located on the central axis of the cylindrical capsule; with NDT device for pipeline placed inside the pipeline, the central axis of cylindrical capsule and the central axis of pipeline are collinear, the sealing rubber cup is placed in front of the probe testing assembly, and because the edge of the sealing rubber cup is tightly propped against the inner pipe wall, inner pipe wall can be cleaned by the sealing rubber cup with NDT device for pipeline moving forward, also with sealing end of sealing rubber cup moving in the same direction as elastic testing element of probe testing assembly but in the opposite direction to mobile carrier, that is, with mobile carrier moving forward, the sealing end of the sealing rubber cup and the elastic testing element are moving backward, while with mobile carrier moving backward, the sealing end of the sealing rubber cup and the elastic testing element are moving forward, so that with the mobile carrier moving forward, the sealing rubber cup and the elastic testing element are moving forward along the inner pipe wall.
Further, all of the said data processing unit, the first signal conditioning unit and second signal conditioning unit are installed inside the cylindrical capsule, and the battery module that is used to supply power for the data processing unit is also installed inside the cylindrical capsule.
Further, a bumper board is also installed at the head of the mobile carrier, wherein said bumper board covers the head of the mobile carrier or is directly installed on the front end face of the mobile carrier, to on one hand protect such head, and on the other hand control the impact force applied to the mobile carrier moving forward.
Further, said probe testing assembly is divided into at least two sets, each of which is installed in sequence outside the mobile carrier along the axis of the mobile carrier, wherein such installation of probe testing assembly outside the mobile carrier means that only the testing element other than the entire structure of the probe testing assembly is located outside the mobile carrier upon installation of the elastic testing assembly; there are multiple testing components in each set of the probe testing assembly, the pipe walls in the circumferential direction can be covered by the total range of testing contributed by testing probes on said multiple testing components, and under the common effect contributed by the testing probes on multiple testing components, the entire circumferential profile of the pipeline can be tested with NDT device for pipeline moving forward inside the pipeline, so that the NDT device for pipeline can move forward in a rotation-free manner.
Further, said testing element is of an elastic testing element, which can not only deform by itself but also move flexibly at the radial direction of the pipeline so that the elastic testing element can deform while impacting an object or bearing an external force. With the NDT device for pipeline placed inside the pipeline, each of the elastic testing elements, during the testing, can be propped against the inner pipe wall, so that the outer side of the elastic testing element can be propped against tightly the inner pipe wall.
Further, said elastic testing element is made of elastic materials which cover testing probes inside, wherein the testing probes are encapsulated in the course of production and fabrication of the elastic testing elements, so there is no need to install the testing probes upon production of the elastic testing element, which can significantly improve both the encapsulation effect of the testing probes and the production efficiency of the elastic testing probes.
Further, a contact surface for testing is formed at one side of the elastic testing element that is propped against the inner pipe wall, i.e. surface contact is formed between the elastic testing element and the inner pipe wall. Because the elastic testing element can deform by itself, once the elastic testing element is propped against the inner pipe wall, said contact surface for testing can be attached to the inner pipe wall.
Further, said testing component is also provided with a connector, wherein such connector and the elastic testing element can be made of same or different materials and are of an integrated structure, mainly referring to that the connector and the elastic testing element are fixed into an integrated structure or they are of the integrated structure at the beginning. No restrictions are applied to the materials of the connector, and such connector is installed on the mobile carrier so that the testing components can be installed on the mobile carrier. With testing components installed and fixed, the elastic testing element can, under the elastic effect, move at the radial direction of the connector, so that the elastic testing element can deform while impacting an object or bearing an external force.
Further, said testing component is also provided with a transition section that is located between the connector and the elastic testing element, that is, the connector, the transition section, and the elastic testing element are integrated, mainly referring to that the connector and the transition section are fixed into the integrated structure, and the transition section and the elastic testing element are fixed into the integrated structure, or the testing components are of integrated structure at the beginning; moreover, the connector and the mobile carrier are connected vertically, preferably referring to that the surface of the connector is vertical to the surface of the mobile carrier, but this connector can also be connected in parallel to the mobile carrier, that is, the surface of connector is in parallel to the surface of the mobile carrier, and therefore the connector can be engaged and fixed onto the mobile carrier.
Further, said probe testing assembly further comprises an annular connector, wherein said annular connector and the elastic testing element can be made of the same or different materials; multiple testing components in the probe testing assembly are spaced on the periphery of the annular connector; the annular connector and the testing element are fixed into the integrated structure or the annular connector is of an integrated structure at the beginning. No restrictions are applied to the materials of this annular connector, and the annular connector can be directly and fixedly sleeved on the mobile carrier or indirectly fixed after being sleeved on the mobile carrier. The elastic testing element can, under the elastic effect, move at the radial direction of the annular connector, so that the elastic testing element can deform while impacting an object or bearing an external force.
Further, said testing component is also provided with a transition section that is located between the annular connector and the elastic testing element, that is, the annular connector, the transition section and the elastic testing element are integrated, mainly referring to that the annular connector and the transition section are fixed into the integrated structure, and the transition section and the elastic testing element are fixed into the integrated structure, or the probe testing assembly is of an integrated structure at the beginning.
Further, the first signal conditioning unit comprises a digital-to-analog conversion module and a first signal amplification module which are connected in sequence; and the second signal conditioning unit comprises a second signal amplification module and an analog-to-digital conversion module which are connected in sequence.
Said system further comprises a management control unit and/or a host computer in a two-way connection with the data processing unit.
Further, the geometrical centers of said excitation coil, passive resonance coil and receiving coil are collinear.
Further, said excitation coil is of a differential coil, while said passive resonance coil and receiving coil are of absolute coils.
Further, said excitation coil, passive resonance coil and receiving coil are PCB planar coils or FPC planar coils.
Further, said excitation coil is provided with two rectangular field coils subject to a symmetrical layout.
Further, said passive resonance coil is provided with multiple secondary resonance coils on PCB that are subject to serial connection and stratified layout; and said receiving coil is provided with multiple secondary receiving coils on PCB that are subject to serial connection and stratified layout.
Further, a resonance point regulating capacitor is connected in series with said passive resonance coil.
Further, said mobile carrier is also provided with a mileage testing assembly that is used to acquire mileage data, wherein said mileage testing assembly is used to locate the testing position of the testing probe by testing the position where the mobile carrier is moving forward in the pipeline, to locate the defect in the pipeline.
Further, said mileage testing assembly is provided with a supporting rod, a wheel support, an odometer wheel and a mileage detector; the supporting rod is installed on the mobile carrier and can swing up and down; the wheel support is installed on the supporting rod and can swing left and right, wherein this design focuses on that the direction of swinging of wheel support is different from the direction of swinging of supporting rod, that is, the supporting rod can also swing left and right while the wheel support can swing up and down; the odometer wheel is installed rotatably on the wheel support, with NDT device for pipeline moving forward inside the pipeline, the odometer wheel is propped against tightly the inner pipe wall; odometer wheel will rotate with the NDT device for pipeline moving forward, and then the mileage detector installed on the wheel support can, based on the number of revolutions of the odometer wheel, acquire the mileage data; the output end of the mileage detector is connected with the data processing unit, to calculate the position where the mobile carrier moves forward as per the perimeter of the odometer wheel and number of revolutions of the odometer wheel, thereby locating the testing probe and further the defect in the pipeline.
Further, the sealing end cap is installed at one end of the wheel support close to the sensor, wherein said sealing end cap is in a shape of the cap and a cavity is formed between the sealing end cap and the wheel support; preferably said cavity is of a sealing chamber, but can also be of a non-sealing chamber, with mileage detector inside.
Further, spring is also connected between the supporting rod and the mobile carrier, wherein the spring, the supporting rod, and the mobile carrier are connected into a triangular structure, the spring can itself provide an elastic effect, and this structure is mainly applicable to the installation that the supporting rod can swing up and down relatively to the mobile carrier, and wheel support can swing left and right relatively to the supporting rod; the spring is connected between the supporting rod and the wheel support for supporting rod to swing left and right relatively to the mobile carrier and the wheel support to swing up and down relatively to the supporting rod.
Further, said mobile carrier is also provided with a mounting seat on which the supporting rod is hinged, so that the supporting rod can be installed on the mobile carrier through the mounting seat that is directly fixed on the mobile carrier, to avoid the supporting rod from directly being hinged with the mobile carrier.
Further, an open slot is formed at the connection between the supporting rod and the wheel support, wherein the wheel support is hinged and installed into the open slot, and the point of hinge for wheel support is located in the open slot and can be protected by the periphery of the open slot.
Further, the open slot is formed on the end face of the supporting rod that is rectangular, wherein no restrictions are applied to the shape (rectangle) of this open slot, but the specific shape of the open slot can depend on the actual installation. A rectangular open slot is only a preferential embodiment.
Further, multiple mileage detector assemblies are spaced at the circumferential direction of the mobile carrier, wherein these assemblies can be spaced at a fixed interval or not, i.e. no restrictions are applied to the spacing between the mileage detector assemblies. The invention has the following beneficial effects:
Eddy current testing is realized by the data processing unit, the first signal conditioning unit, the second signal conditioning unit, and the testing probe without additional magnetizing treatment devices, thus greatly reducing the volume of the system. The cleanliness requirement for the inside of the pipeline is greatly reduced due to the certain lift-off testing capacity of the testing probe. In addition, based on the high integration of the testing probe, the invention not only improves the flexibility of the device through the pipeline but also greatly reduces the system cost. Further, by introducing a passive resonance coil between the excitation coil and the receiving coil in the invention, the coupling between the excitation coil and the receiving coil can be enhanced, thus significantly improving the energy transmission efficiency, further improving the sensitivity of the testing probe so that the probe can accurately test the pipeline defects at a higher lift-off height, and ultimately improving the defect detection capacity of the probe.
By integrating the data processing unit, the first signal conditioning unit, the second signal conditioning unit, the battery module and the management control unit into the cylindrical capsule, the overall structural design is more compact and the dimensions are smaller, making it easy for the device to pass through the pipeline elbow with small curvature, and making it possible for the device to be used for mileage testing and operate normally in the high-pressure environment without short circuit caused by water ingress.
By setting the testing element as an elastic testing element and making the elastic testing element move elastically in the radial direction of the pipeline, the elastic testing element can always be propped against and attached onto the inner pipe wall during testing, thus improving the signal quality and the testing accuracy.
By arranging at least two groups of probe testing assemblies, and making the total range of testing contributed by multiple testing probes cover the pipe wall in the circumferential direction, the range of testing can effectively cover a complete inner pipe wall in the circumferential direction, thus realizing 360° complete movement testing, and avoiding the problem that the pipe wall cannot be completely covered in the circumferential direction due to the arrangement of only one group of probe testing assemblies and the gap caused by radial movement of the elastic testing element.
By using the elastic testing element made of elastic material and wrapping the testing probe with elastic material, the probe is sealed so that it has better water pressure resistance. In addition, with a specific angle, the elastic testing element can ensure that the probe fits well with the pipe wall, and provide sufficient supporting force to prevent the testing probe from shaking during testing and thus make it more stable.
By providing a mileage detector to collect the mileage information of the mobile carrier carried by the invention, the pipeline defects can be located accurately.
By providing a host computer to analyze the testing information fed back by the testing probe, the presence of defects of the pipeline can be determined and the position of the defective pipeline can be located. In addition, the host computer can also transmit the analysis results of these data to the server to realize data storage and sharing, and thus realize defect information traceability management for different pipelines.
By aligning the geometric centers of the excitation coil, the passive resonance coil and the receiving coil, the energy transmission efficiency can be maximized.
The excitation coil is a differential coil, while the passive resonance coil and the receiving coil are absolute coils. The differential coil can form uniform eddy current in the central area of the coil and can generate obvious eddy current change in the middle eddy current area when defects are detected, thus changing the magnetic field and facilitating the identification of defective parts.
Adopting PCB planar coil or FPC planar coil, the probe has the characteristics of small size and high sensitivity to surface defects. In addition, with small effective lift-off, the probe is highly sensitive to defects and has broad application prospects in the field of eddy current testing. Further, the PCB planar coil can be directly manufactured and permanently fixed on the moving assembly.
In addition, the FPC planar coil is elastic enough to allow consistency of the coil with the pipe surface to be tested, so the testing probe also has a very broad prospect in testing complex surface geometry.
Under the action of the resonance coil, the secondary receiving coils arranged in a multilayered structure can improve the testing sensitivity while reducing the optimal testing frequency, and effectively reducing the requirements for excitation signals. Meanwhile, a multi-coil array created by a plurality of resonance sub-coils and receiving sub-coils can increase the testing range and reduce the testing time.
By adjusting the resonance point of the capacitance regulating coil of the resonance point regulating capacitor, the testing capacity of the testing probe can be improved to be suitable for a wider testing environment.
Marks and names of corresponding parts and components as shown on the drawings:
1—mobile carrier; 11—cylindrical capsule; 12—battery module; 2—probe testing assembly; 21—connector; 22—transition section; 23—elastic testing element; 24—testing probe; 21′—annular connector; 22′—transition section; 23′—elastic testing element; 3—mileage testing assembly; 31—mounting seat; 32—supporting rod; 33—wheel support; 34—odometer wheel; 35—spring; 36—open slot; 37—sealing end cap; 38—mileage detector; 4—bumper board; 5—sealing rubber cup; 6—pressure-resistant connecting wire; 7—pressure-resistant connector; 8—bolt; 9—spacer ring.
The invention will be further described in detail with the following specific embodiments and the attached drawings.
As shown in
Under normal circumstances, the axis of the mobile carrier 1 is parallel to that of the pipeline, and the mobile carrier 1 can automatically advance in the pipeline or advance with the fluid through the carried traveling mechanism or other structures. When the mobile carrier 1 moves in the pipeline under the action of the fluid by carrying other structures, the action is the pushing action caused by the pressure difference between the front and rear sides of the mobile carrier 1 when the fluid flows. When the mobile carrier 1 moves in the pipeline under the action of fluid by carrying a traveling mechanism, the traveling mechanism can specifically include a driving mechanism arranged in the mobile carrier 1 and a traveling wheel arranged on the mobile carrier 1, which is driven by the driving mechanism to rotate. Specifically, the traveling wheels are respectively arranged at both ends of the mobile carrier 1, the probe testing assembly 2 can be arranged on the mobile carrier 1 between the traveling wheels, the traveling mechanism can be arranged outside or inside the mobile carrier 1, and existing technology can be adopted for the traveling mechanism.
The probe testing assembly 2 comprises a testing component installed on the mobile carrier 1 and having a testing element in which the testing probe 24 is encapsulated. When the mobile carrier 1 is advancing, the testing probe 24 corresponds to the inner pipe wall, so that the testing probe 24 can test the inner pipe wall.
As shown in
In this embodiment, an eddy current testing system is formed by the data processing unit, the first signal conditioning unit, the second signal conditioning unit and the testing probe 24 without additional magnetizing treatment devices, thus greatly reducing the volume of the system. The cleanliness requirement for the inside of the pipeline is greatly reduced due to the certain lift-off testing capacity of the testing probe. In addition, based on the high integration of the testing probe, the NDT device for pipeline provided by the invention not only improves the flexibility of the device through the pipeline, but also greatly reduces the system cost. Further, the excitation coil generates a primary magnetic field under the action of the excitation signal and is mutually induced with the receiving coil so that the energy of the excitation coil is wirelessly transmitted to the receiving coil. By introducing the passive resonance coil between the excitation coil and the receiving coil, the coupling between the excitation coil and the receiving coil can be enhanced, thereby significantly improving the energy transmission efficiency between the transmitting coil and the receiving coil, further improving the sensitivity of the testing probe 24 so that the probe can accurately test pipeline defects at a higher lift-off height, and improving the defect detection capability of the testing probe 24.
In some other embodiments, as shown in
The head of said mobile carrier 1 is also provided with a bumper board 4 made of rubber material, which not only avoids the damage to the cylindrical capsule 11 caused by the direct impact of the invention on the elbow of the pipeline during high-speed advancement of the invention but also avoids the damage to the data processing unit, the first signal conditioning unit, the second signal conditioning unit and the battery module 12 in the cylindrical capsule 11 caused by excessive shock during the impact process.
If there are two groups of sealing rubber cups 5 and probe testing assemblies 2, one group of sealing rubber cups 5 and probe testing assemblies 2 are tightly installed on the cylindrical capsule 11 by flanges and bolt 8, while the other group of sealing rubber cups 5 and probe testing assemblies 2 are also tightly installed at the rear end of the cylindrical capsule 11 by flanges and bolt 8. To provide a certain movable space for probe testing assembly 2 at the rear side of sealing rubber cup 5, a spacer ring 9 can also be provided between probe testing assembly 2 and the adjacent sealing rubber cup 5.
In some other embodiments, as shown in
In some specific embodiments, the testing element is an elastic testing element 23, so that each testing component in the probe testing assembly 2 tests the inner pipe wall through its elastic testing element 23. The elastic motion direction of the elastic testing element 23 is in the radial direction of the pipeline, thus enabling each elastic testing element 23 to be propped against the inner pipe wall when testing the inner pipe wall, effectively contacting the inner pipe wall through the elasticity of the elastic testing element 23 during movement testing, and providing a relatively stable supporting force, thereby improving signal quality and the testing accuracy while achieving the sealing and good water pressure resistance of the probe.
Here, it should be explained that in the case of propping of the elastic testing element 23 against the inner pipe wall, “propping” includes surface propping and line propping, depending on the testing mode or testing object of the carried testing probe 24.
In some other embodiments, the elastic testing element 23 is made of elastic material, and the testing probe 24 is wrapped with the elastic material, so that the elastic testing element 23 has elasticity and can move radially, resulting in a possible gap between two adjacent elastic testing elements 23 in the same probe testing assembly 2 in a natural state or under small stress. As a result, the entire circumference cannot be covered; in other words, the total range of testing contributed by the elastic testing probes 24 in one group of probe testing assemblies 2 cannot completely cover the pipe wall in the circumferential direction. Therefore, by arranging at least two groups of probe testing assemblies 2, sequentially arranging the testing components of each group of probe testing assemblies on the outer side of the mobile carrier 1 along the axis of the mobile carrier 1, and arranging the elastic testing elements 23 on the adjacent two groups of probe testing assemblies in a staggered manner, the two groups of probe testing assemblies can cooperate so that the pipe walls in the circumferential direction can be covered by the total range of testing contributed by the elastic testing elements 23, thus realizing 360° complete testing of the inner pipe wall, making the testing more comprehensive and effective.
The purpose of the staggered arrangement of more than two groups of probe testing assemblies 2 is mainly to make the range of testing contributed by each elastic testing element 23 cover the entire circumference and provide a certain overlap width. Taking the surface propping as an example, if the width of the propped contact surface, i.e., the width of the testing coverage surface provided by a single testing probe 24 is W, the number of elastic testing elements 23 arranged is n, and the inner diameter of the pipeline is D1, the relation will be
After N1 is calculated, the result is rounded up to an even number to obtain the number of probes to be arranged (n), and the number of probes to be arranged at the front and rear ends are n/2.
In this way, the entire circumference can be covered by two groups of probe testing assemblies. In addition, the above relation shall be satisfied if three or more groups of N are arranged. In other words, after N1 is calculated, the result is rounded up to an integer to obtain the number of probes to be arranged (n), and n/N probes shall be arranged in a staggered manner in the front and rear groups respectively.
In some specific embodiments, the elastic material for the elastic testing element 23 is rubber material or polyurethane material with high elasticity and toughness, and rubber material is preferably used as the elastic material for the embodiments.
In some specific embodiments, as shown in
It can be understood that since the elastic testing element 23 is elastic and its contact surface for testing should be attached to the pipe wall during testing, i.e. when the elastic testing element 23 is in a natural state or an unstressed state, said contact surface for testing or the elastic testing element 23 is not parallel to the axis of the mobile carrier 1 and there is a certainly included angle α (preferably within the range of 3°-7°, depending on the elastic material to be used), the diameter of the testing element of the probe testing assembly 2 larger than the diameter of the inner pipe wall before testing can be changed to a diameter equal to the diameter of the inner pipe wall during testing, and at the same time, said testing element can be attached to the inner pipe wall.
As shown in
Specifically, as shown in
To better construct the testing component and make the constructed testing component be attached to the inner pipe wall, a transition section 22 is provided between the connector 21 and the elastic testing element 23 as shown in
If the probe testing assembly 2 is of a split structure, the probe testing assembly 2 can be integrally molded by a mold directly, and the testing probe 24, which is an NDT testing probe 24, is directly encapsulated in the probe testing assembly 2 during the molding process. Furthermore, set
where R1 is the radius of the inner end of the elastic testing element 23, D1 is the inner diameter of the pipeline, R2 is the radius of the outer end of the elastic testing element 23, and R2 is slightly larger than R1. With the installation position of the testing probe 24 determined, the probe testing assembly 2 is subject to compressive deformation on the inner pipe wall, so that the angle α becomes close to 0°, thus ensuring that the testing probe 24 is attached onto the pipe wall.
As shown in
When the probe testing assembly 2 with integral structure is installed, the annular connector 21′ is vertically connected with the mobile carrier 1, and a transition section 22′ can be arranged between the annular connector 21′ and the elastic testing element 23′, as shown in
When there are two groups of probe testing assemblies 2 with integral structure, the elastic testing element 23′ of the two groups of probe testing assemblies 2 have a certain angular difference in the circumferential direction, so that the testing probe 24 can be fully covered in the circumferential direction. For example, if one group of probe testing assembly 2 has N flexible testing elements 23′ uniformly distributed along the circumferential direction, the angular difference between the front and rear groups of probe testing assemblies 2 is
the angle is designed as
where D1 is the inner diameter of the pipe, R1 is the radius of the inner end of the elastic testing element 23′, R2 is the radius of the inner end of the elastic testing element 23′, and R2 is slightly larger than R1, so that the elastic testing element 23′ is basically flush with the inner wall of the pipe after being squeezed by the inner wall.
In some other embodiments, the first signal conditioning unit includes a digital-to-analog conversion module and a first signal amplification module connected in sequence; and the second signal conditioning unit comprises a second signal amplification module and an analog-to-digital conversion module connected in sequence. More specifically, the digital-to-analog conversion module is of an ADC chip; The first signal amplification module is specifically a power amplifier; The second signal conditioning unit comprises a power supply voltage regulating chip for providing 5V operating voltage and a power supply voltage regulating chip for providing 3.3V operating voltage, an operational amplifier for amplifying signals and a standard voltage chip for providing 4.096V voltage. The 4.096V voltage is divided into 2.048V voltage, which is supplied to the operational amplifier and then output to the ADC chip (analog-to-digital conversion module) after differential amplification. The ADC acquisition chip is a 16-bit, IMSPS, true-differential input, digital-to-analog converter, and provides SPI interface to output the acquired testing data to the data processing unit. It also comprises a 4-bit dual power transceiver and supports bidirectional level conversion. The signal converted by ADC and the clock provided by the data processing unit allows a stronger circuit against interference through the chip. As an option, the signal conditioning unit further comprises a filtering module, which is connected with the signal amplification module and used for filtering a clutter signal.
In some other embodiments, the NDT device for pipeline further comprises a management control unit and a host computer which are bidirectionally connected with the data processing unit, wherein the management control unit is connected to the host computer while the host computer is connected to the server. Specifically, the management control unit is used for self-inspection of the testing probe 24, IMU self-inspection, configuration management, data file management, etc., wherein the self-inspection of the testing probe 24 performs start-stop control and real-time data viewing; configuration management is used to test parameter configuration, RTC timing and parameter configuration for local storage of equipment; data file management is mainly used for data file reading and conversion. Further, the host computer is equipped with data acquisition management software, the data processing unit transmits the testing information (data) fed back by the second signal conditioning unit to the management control unit for storage, and the management control unit further transmits the feedback information to the host computer via the data management software, or the management control unit transmits the feedback information to the data management software of the host computer via the wireless communication module. The testing information is analyzed through the data management software integrated into the host computer, to judge whether the defects occur in the pipelines and to locate the defective pipelines. The host computer transmits the data analysis results to a server at the same time, thus realizing data storage and sharing.
In some other embodiments, the geometric centers of the excitation coil, the passive resonance coil and the receiving coil are collinear, i.e., the excitation coil, the passive resonance coil and the receiving coil are arranged coaxially, improving the energy transmission efficiency to the maximum extent.
In some other embodiments, the excitation coil, the passive resonance coil and the receiving coil are of rectangular coils spirally wound with copper wire, in which the defects are more easily to be identified compared with others in the circular structure.
In some other embodiments, the excitation coil is a differential coil, and the passive resonance coil and the receiving coil are absolute coils. The differential coil can form a uniform eddy current in the central area of the coil, and can generate obvious eddy current change in the middle eddy current area when defects are detected, thus changing the magnetic field and facilitating the identification of defective parts.
In some other embodiments, the excitation coil, the passive resonance coil and the receiving coil are PCB planar coils or FPC planar coils, which are characterized by small size and high sensitivity to surface defects; they have high sensitivity to defects due to the small effective lift-off, and broad prospects in the field of eddy current testing. Further, the PCB planar coil can be directly manufactured and permanently fixed on the moving component. In addition, the FPC planar coil is flexible enough, allowing consistency of the coil with the pipe surface to be detected, so the testing probe 24 also has a very broad prospect in testing complex surface geometry.
In some other embodiments, the excitation coil comprises two symmetrically arranged rectangular field coils to generate more uniform eddy currents under the action of excitation signals.
In some other embodiments, as shown in
In some other embodiments, the passive resonance coil comprises multiple PCB resonance sub-coils which are connected in series and arranged in layers. As a preferred embodiment, the testing probe 24 comprises four layers of passive resonance coils. As shown in
In some other embodiments, the receiving coil comprises a plurality of PCB receiving sub-coils which are connected in series and arranged in layers. As a preferred embodiment, the testing probe 24 comprises four layers of receiving sub-coils. As shown in
As a preferred embodiment, the testing probe 24 of the invention comprises an excitation coil, four layers of resonance sub-coils, and four layers of receiving sub-coils. The whole probe is small in size and convenient to install. For the invention, under the action of the resonance coil, the receiving coil arranged in a multilayered structure can improve the inductance value of the coil, etc., and further can better induce the change in the magnetic flux of the pipeline to be tested, thus improving the testing sensitivity, reducing the optimal testing frequency, and effectively reducing the requirements on excitation signal. Further, a multi-coil array created by a plurality of resonance sub-coils and receiving sub-coils can increase the testing range and reduce the testing time.
In some other embodiments, bending positions of the excitation coil, the passive resonance coil, and the receiving coil are all chamfered at 45° to reduce electromagnetic interference and signal emission, and reducing the signal noise when the external signal frequency is high.
In some other embodiments, the passive resonance coil is connected with a capacitor in series, which is connected with the capacitor via a wire on the left side of the coil. When the passive resonance coil comprises a plurality of resonance sub-coils, one resonance sub-coil is connected in series with a resonance point regulating capacitor, and two via holes are specifically formed outside the resonance sub-coil to place the capacitor. The resonance point of the coil can be adjusted by the capacitance of the capacitor, thereby improving the interference rejection of the testing probe 24 to be suitable for a wider testing environment.
To further illustrate the inventive concept, the testing principle is described as follows:
The NDT device for pipeline is arranged on the mobile carrier 1 and placed in a conductive pipeline to be tested, and the invention starts to work after being powered on. The data processing unit FPGA generates a sine wave excitation signal through a first digital-to-analog conversion module DAC by a DDS method, and the sine wave excitation signal is amplified to 6V by a power amplifier and applied to the excitation coil; the excitation coil is driven by the excitation signal to generate a primary magnetic field, and a passive resonance coil enhances the coupling between the excitation coil and the receiving coil and the tested pipeline. When the tested specimen (tested pipeline) is in the primary magnetic field, the primary magnetic field generates eddy current on the surface of the tested specimen and the flow direction of the eddy current changes at the defect. A secondary magnetic field generated by the eddy current changes due to a change in the eddy current. Changes in the amplitude and phase of the receiving coil are detected by detecting a change in the magnetic flux of the receiving coil. Therefore, the induced voltage generated by the received primary magnetic field and the induced voltage generated by the secondary magnetic field (feedback testing signal) are amplified by the operational amplifier, converted into digital signals recognizable by the data processing unit FPGA through the ADC, and then transmitted to the data processing unit. The data processing unit transmits the feedback testing signal to the host computer. The host computer extracts the amplitude and phase value of the testing signal, obtains the change in the amplitude and phase of the testing signal, and accurately detects the relevant defect information of the tested specimen and the positions of defective pipelines in combination with the coded signal fed back by the encoder.
To further illustrate the technical effect of the application, a concrete testing effect diagram of the resonance coil introduced for the testing probe 24 of the application is given. Wherein
Further, the length, width, and thickness of the artificial defect sample in the application are 450 mm, 300 mm, and 10 mm respectively.
In some other embodiments, as shown in
In some other embodiments, a sealing end cap 37 is arranged at one end of the wheel support 33 close to the sensor, a cavity is formed between the sealing end cap 37 and the wheel support 33, and the mileage detector 38 is placed inside said cavity. When the odometer wheel 34 rotates, the mileage detector 38 generates pulse signals, which are transmitted to the data processing unit and recorded by the management control unit after being processed by the data processing unit, thereby calculating the running mileage of the equipment.
In some other embodiments, a spring 35 is also provided and connected between the supporting rod 32 and the mobile carrier 1, and the spring 35 is a tension spring. Under the action of spring 35, the supporting rod 32 moves radially, so that the wheel surface of the odometer wheel 34 is pressed against the inner wall of the pipeline, which effectively increases the resistance between the wheel surface of the odometer wheel 34 and the inner wall of the pipeline, thus ensuring that the odometer wheel 34 rotates when the invention advances, and making the testing of the mileage detector 38 more accurate.
In some other embodiments, the mobile carrier 1 is also provided with a mounting seat 31, which is fixed on the outer wall of the mobile carrier 1, and the supporting rod 32 is connected by the hinge on the mounting seat 31, so that the supporting rod 32 is not directly connected with the mobile carrier 1, which effectively prevents the supporting rod 32 from directly acting on the mobile carrier 1 when it is subjected to external force, thus effectively protecting the mobile carrier 1.
In some other embodiments, as shown in
In some other embodiments, the open slot 36 is formed on the end face of the supporting rod 32 and is in a rectangular shape, which ensures that while the wheel support 33 can swing against the supporting rod 32, the swing amplitude of the wheel support 33 against the supporting rod 32 can be limited, to avoid jamming when the device passes through the pipe elbow, and swing in a small range can improve the accuracy of odometer wheel 34.
In some other embodiments, there are multiple mileage testing assemblies 3 that are spaced circumferentially along with the mobile carrier 1, which effectively avoids the slipping of the odometer wheel 34 and inaccurate mileage recording, and allows mutual calibration among multiple mileage testings, thereby solving the problem of slipping off the odometer wheel 34 and inaccurate mileage recording.
The odometer wheel 34 mounted on the wheel support 33 can be displayed in the upper, lower, left, and right directions, through the cooperation of the supporting rod 32 and the wheel support 33. When the invention is used, the supporting rod 32 can swing outwards under the action of the spring 35, so that the wheel support 33 swings synchronously, and the odometer wheel 34 mounted on the wheel support 33 is pressed against the inner wall of the pipeline. When the NDT device for pipeline rotates in the forward process, the wheel support 33 swings against the supporting rod 32, so that the odometer wheel 34 on the wheel support 33 can swing along with the wheel support 34 to a certain extent, effectively preventing the odometer wheel 34 from being subjected to torsional force when the NDT device for pipeline rotates, thus making the odometer wheel 34 always press against the inner wall of the pipeline, avoiding the odometer wheel 34 from slipping, and greatly improving the testing accuracy of the mileage detector.
To improve the pressure resistance and waterproofness of the invention, all the electrical components in the cylindrical capsule 11 are connected with the mileage detector 38 and the testing probe 24 through the pressure-resistant connecting wire 6 with the pressure-resistant connector 7, and the communication between the testing probe 24, the mileage detector 38 and the internal circuit hardware is realized through the pressure-resistant connecting wire 6, and the cylindrical capsule can work normally in a high water pressure environment without being short-circuited due to the inflow of water. In addition, the front and rear end covers of the cylindrical capsule 11 are respectively fitted with sealing rings, so that the whole capsule is sealed to protect the battery module 12 and circuit components.
When the invention is placed in the pipeline, the edge of the sealing rubber cup 5 will be attached to the inner wall of the pipeline and the cylindrical capsule 11 will be located in the center of the pipeline through the sealing rubber cup 5 to divide the pipeline into two parts; because of the elasticity of the probe testing assembly 2, when the invention is placed in the pipeline, the probe testing assembly 2 will be deformed, and the elastic testing element 23 of the probe testing assembly 2 will be attached to the inner wall of the pipeline, and by the elasticity of the spring 35, the supporting rod 32 moves radially under the action of the spring 35, so that the wheel surface of the odometer wheel 34 is pressed against the inner wall of the pipeline.
The fluid is sent into the pipeline, forming pressure difference on both sides of the sealing rubber cup 5 and moving the invention forward in the pipeline. While the invention moves forward, the testing probe 24 in the elastic testing element 23 starts to detect the inner wall of the pipeline, while the mileage detector 38 collects mileage information through the rotation of the odometer wheel 34, and the data processing unit FPGA of the testing probe 24 generates sine wave excitation signals through the first digital-to-analog conversion module DAC by DDS method. After being amplified by the power amplifier to 6V, it is applied to the excitation coil, which generates a primary magnetic field driven by the excitation signal. The passive resonance coil enhances the coupling between the excitation coil and the receiving coil and the pipeline to be tested. When the tested part (pipeline to be tested) is in the primary magnetic field, the primary magnetic field generates eddy current on the surface of the tested part and the flow direction of the eddy current changes at the defect. Because the eddy current changes, the secondary magnetic field generated by the eddy current changes. By detecting the change of the magnetic flux of the receiving coil, and then detecting the change of the amplitude and phase of the receiving coil, the received induced voltage generated by the primary magnetic field and the induced voltage generated by the secondary magnetic field (feedback testing signal) are amplified by the operational amplifier, and the digital signal which can be recognized by the data processing unit FPGA is converted by the ADC and transmitted to the data processing unit, which transmits the feedback testing signal to the host computer. The host computer extracts the amplitude and phase value of the testing signal, obtains the amplitude and phase change of the testing signal, and combines the coded signal fed back by the encoder to accurately detect the relevant defect information of the tested piece and the position of the corresponding defective pipeline.
The in-pipeline testing device provided by the invention has the following advantages:
The probe testing assembly has a good overall packaging effect, with the sealing performance of the probe guaranteed under the high-pressure environment (3-20Mpa) inside the pipeline;
The probe testing assembly is of high resiliency, and the testing probe has a good joint effect with the pipe wall without fatigue fracture;
The probe testing assembly is molded, so that the testing probes are accurately positioned inside and have good manufacturing consistency;
The probe testing assembly is packaged as a single part without other connecting or supporting parts; the parts falling off during the operation of the probe testing assembly in the pipeline are reduced;
The testing probe by adopting the passive resonance coil has high testing sensitivity and a higher lift-off value; integration of the testing probe with the mobile carrier and mileage testing assembly can improve the flexibility of the equipment in the pipeline.
The testing probe is packaged at the same time as the probe testing assembly is produced, and because the probe testing assembly is under injection molding, the distance between the testing probe and the outer surface of the elastic testing element can be controlled by the mold so that the proper size can be achieved, the lift-off value between the testing probe and the surface to be tested can meet the best requirements, and the testing probe signal can be optimized.
The embodiments above are only the preferred embodiments for the invention and not used to restrict the invention. For the technicians of the field, various modifications and changes can be made to the invention. Any modification, equivalent replacement and improvement within the concept and principle of the invention, are covered by the range of protection by the invention.
This application is a Continuation of the U.S. application Ser. No. 17/527,133 filed on Nov. 15, 2021, and entitled “Non-destructive Testing Device for Pipeline”, now pending, the entire disclosures of which are incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| Parent | 17527133 | Nov 2021 | US |
| Child | 18748315 | US |
