CN110823998A - A flexible rotating eddy current detection sensor for the heat transfer tube of the evaporator of a nuclear power plant - Google Patents

Abstract

The invention discloses a flexible rotating eddy current detection sensor for a heat transfer tube of an evaporator of a nuclear power plant. The cable in the flexible connector, the functional components respectively include a guide cone component, a plane coil component, a quadrature coil component, a reference coil component, and a multi-core connector component. The guide cone component and the multi-core connector component are located at both ends respectively, and the front end of the cable The front part and the rear end part are respectively fixedly connected with the guide cone assembly and the multi-core joint assembly. The sensor probe of the present invention uses a combination of two types of coils, plane and orthogonal, and is placed in a plane coil material, a plane coil carrier, an orthogonal coil material and an orthogonal coil carrier made of high-elastic plastic sheets. The middle petal ensures good contact between the coil and the tube wall, the signal is stable and the response is large, and the reliability of the eddy current detection is enhanced.

Description

A flexible rotating eddy current detection sensor for the heat transfer tube of the evaporator of a nuclear power plant

technical field

The invention belongs to the field of nuclear power eddy current detection equipment, in particular to a flexible rotating eddy current detection sensor for a heat transfer tube of an evaporator of a nuclear power plant.

Background technique

Eddy current testing technology is one of the non-destructive testing methods in the industry. According to the principle of electromagnetic induction, it can detect surface and near-surface defects of conductive materials. During detection, the coil does not need to be in direct contact with the object to be measured, and can perform high-speed detection, which is easy to automate.

The heat transfer tube of the steam generator is an important part of the pressure-bearing boundary of the primary circuit of the pressurized water reactor nuclear power unit. With the increase of the operating time, the heat transfer tube will have wall thickness reduction, pitting corrosion, intergranular and other mechanisms due to chemical and mechanical mechanisms. Corrosion/stress corrosion cracks, fatigue, wear and other degradation, which directly threaten the long-term safe and stable operation of the unit, so the annual regular maintenance of the nuclear power plant will take the heat transfer tube as the key inspection object, and the heat transfer tube of the evaporator will be inspected. The only effective method is eddy current testing, that is, non-destructive testing from the inner wall of the pipe with an in-penetrating eddy current probe. The inspection generally takes two steps. First, the BOBBIN probe is used to inspect the whole heat transfer tube, that is, the probe is first pushed to the other end of the heat transfer tube, and then the probe is pulled back at a constant speed and the pullback signal is recorded. When a suspicious signal is found, the rotating probe is used to re-verify the defect. However, there is a defect in the use of conventional rotary probes for re-examination. The commonly used rotary probes are rigid probes, which cannot pass through the elbow section of the heat transfer tube. When the BOBBIN probe finds a suspected defect in the elbow section, there is no suitable qualitative judgment method.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a flexible rotating eddy current detection sensor for a heat transfer tube of an evaporator of a nuclear power plant.

In order to solve the above technical problems, the present invention adopts the following technical solutions: A flexible rotating eddy current detection sensor for a heat transfer tube of an evaporator of a nuclear power plant, which includes a plurality of functional components connected in series and a flexible connector connected between two adjacent functional components and cables passing through a plurality of the functional assemblies and flexible connectors, the functional assemblies respectively include a guide cone assembly, a plane coil assembly, a quadrature coil assembly, a reference coil assembly, and a multi-core joint assembly. The assembly and the multi-core connector assembly are located at two ends respectively, and the front end and the rear end of the cable are respectively fixedly connected with the guide cone assembly and the multi-core connector assembly.

Preferably, the guide cone assembly includes a guide cone body and a nylon connector fixedly connected to the guide cone body, and the front end of the cable is fixedly connected to the nylon connector of the guide cone assembly.

Preferably, the planar coil assembly includes a planar coil base, a planar coil blank inserted on the peripheral surface of the planar coil base, a planar coil carrier fixed on the planar coil blank, and a planar coil carrier provided on the planar coil base. The plane coil body in the coil carrier and the nylon connectors respectively fixed on the two ends of the plane coil base.

Preferably, the quadrature coil assembly includes a quadrature coil base, a quadrature coil blank inserted on the peripheral surface of the quadrature coil base, and a quadrature coil carrier fixed on the quadrature coil blank , a quadrature coil body arranged in the quadrature coil carrier, and nylon connectors respectively fixed on both ends of the quadrature coil base.

Preferably, the reference coil assembly includes a reference coil body and nylon connectors respectively fixed on both ends of the reference coil body.

Preferably, the multi-core joint assembly includes a multi-core joint body, a lock nut threadedly connected to the front end of the multi-core joint body, and a nylon connector fixedly connected to the front end of the lock nut, The rear end of the cable is fixedly connected with the nylon connector of the multi-core connector assembly.

Preferably, the flexible connecting member is a torsion spring, and the cable passes through the torsion spring.

Preferably, the functional components sequentially include a guide cone component, a planar coil component, a quadrature coil component, a reference coil component, and a multi-core joint component.

Further, the functional assembly further includes centering petals, and the centering petals are arranged between the guide cone assembly and the planar coil assembly and between the quadrature coil assembly and the reference coil assembly.

The beneficial effect of the present invention is that the sensor probe of the present invention uses two types of coils, plane and quadrature, which are combined and placed on the plane coil material, plane coil carrier, quadrature coil material and quadrature coil carrier made of high elastic plastic sheet In the middle, the centering petals are placed before and after the coil to ensure good contact between the coil and the tube wall, the signal is stable and the response is large, which enhances the reliability of eddy current testing; the use of high-strength torsion springs can greatly improve the transmission of torque and make the probe and the drive motor. There is no time delay, and the flexibility and elasticity of the sensor probe are improved. It can easily pass through the elbow section of the heat transfer tube with a minimum curvature radius of 50mm and an inner diameter of 15mm to 25mm for eddy current inspection. The passage and protection of the cable can avoid the damage of the cable by the external environment and human factors.

Description of drawings

Fig. 1 is the perspective view of the present invention;

Figure 2 is an exploded view of the present invention.

Detailed ways

The present invention is described in detail below in conjunction with the embodiments shown in the accompanying drawings:

As shown in Figures 1 and 2, the flexible rotating eddy current detection sensor for the heat transfer tube of the evaporator of the nuclear power plant includes a plurality of functional components connected in series, a flexible connector connected between two adjacent functional components, and a flexible connector that passes through the plurality of functional components and Cable 9 inside the flexible connector. The functional components sequentially include a guide cone assembly 21, a centering petal 4, a planar coil assembly 22, a quadrature coil assembly 23, a centering petal 4, a reference coil assembly 24, and a multi-core joint assembly 25. The guide cone assembly and the multi-core joint assembly are respectively At both ends, the front end and the rear end of the cable 9 are respectively fixedly connected with the guide cone assembly and the multi-core connector assembly.

The guide cone assembly includes a guide cone body 1 and a nylon connector 2 that is bonded and fixedly connected to the guide cone body 1 , and the front end of the cable 9 is fixedly connected to the nylon connector 2 of the guide cone assembly.

The plane coil assembly includes a plane coil base 7, a plane coil material 6 inserted on the peripheral surface of the plane coil base 7, a plane coil carrier 5 fixed on the plane coil material 6, and a plane coil carrier 5 arranged in the plane coil carrier 5. The plane coil body and the nylon connectors 2 respectively adhered and fixed on both ends of the plane coil base 7 . The quadrature coil assembly includes a quadrature coil base 14, a quadrature coil material 13 inserted on the peripheral surface of the quadrature coil base 14, a quadrature coil carrier 8 fixed on the quadrature coil material 13, The quadrature coil body in the quadrature coil carrier 8 and the nylon connectors 2 respectively adhered and fixed on both ends of the quadrature coil base 14 . Two types of coils, plane and quadrature, are combined and placed in the plane coil material 6, the plane coil carrier 5, the quadrature coil material 13 and the quadrature coil carrier 8 made of high elastic plastic sheets. The middle petal 4 ensures that the coil is in good contact with the tube wall, the signal is stable and the response is large, which enhances the reliability of eddy current detection

The reference coil assembly includes a reference coil body 10 and nylon connectors 2 which are respectively bonded and fixed on both ends of the reference coil body 10 .

The multi-core connector assembly includes a multi-core connector body 12 , a locking nut 11 threadedly connected to the front end of the multi-core connector body 12 , and a nylon connector 2 that is bonded and fixedly connected to the front end of the locking nut 11 , and the cable 9 The rear end of the connector is fixedly connected with the nylon connector 2 of the multi-core connector assembly.

The flexible connector is a torsion spring 3 , and the cable 9 is passed through the torsion spring 3 . The use of high-strength torsion spring 3 can greatly improve the transmission of torque, so that there is no time lag between the probe and the drive motor, and improve the flexibility and elasticity of the sensor probe, which can easily pass through a minimum curvature radius of 50mm and an inner diameter of 15mm ~ 25mm At the same time, the hollow structure of the torsion spring 3 is convenient for the passage and protection of the cable 9, so as to avoid the damage of the cable 9 by the external environment and human factors.

The above-mentioned embodiments are only intended to illustrate the technical concept and characteristics of the present invention, and the purpose thereof is to enable those who are familiar with the art to understand the content of the present invention and implement them accordingly, and cannot limit the protection scope of the present invention. All equivalent changes or modifications made according to the spirit of the present invention should be included within the protection scope of the present invention.

Claims (9)

1. The utility model provides a nuclear power station evaporator heat-transfer pipe flexible rotatory eddy current detection sensor which characterized in that: the multi-core cable connector comprises a plurality of serially connected functional components, a flexible connecting piece connected between two adjacent functional components and a plurality of cables penetrating through the functional components and the flexible connecting piece, wherein the functional components respectively comprise a guide cone component, a planar coil component, an orthogonal coil component, a reference coil component and a multi-core connector component, the guide cone component and the multi-core connector component are respectively located at two ends, and the front end part and the rear end part of each cable are respectively fixedly connected with the guide cone component and the multi-core connector component.

2. The flexible rotary eddy current inspection sensor for a heat transfer pipe of an evaporator of a nuclear power plant according to claim 1, characterized in that: the guide cone assembly comprises a guide cone body and a nylon connecting piece fixedly connected with the guide cone body, and the front end of the cable is fixedly connected with the nylon connecting piece of the guide cone assembly.

3. The flexible rotary eddy current inspection sensor for a heat transfer pipe of an evaporator of a nuclear power plant according to claim 1, characterized in that: the planar coil assembly comprises a planar coil base, a planar coil sheet inserted on the circumferential surface of the planar coil base, a planar coil carrier fixed on the planar coil sheet, a planar coil body arranged in the planar coil carrier and nylon connecting pieces fixed on two end parts of the planar coil base respectively.

4. The flexible rotary eddy current inspection sensor for a heat transfer pipe of an evaporator of a nuclear power plant according to claim 1, characterized in that: the orthogonal coil assembly comprises an orthogonal coil base, orthogonal coil material pieces inserted on the peripheral surface of the orthogonal coil base, an orthogonal coil carrier fixed on the orthogonal coil material pieces, an orthogonal coil body arranged in the orthogonal coil carrier and nylon connecting pieces respectively fixed on two end parts of the orthogonal coil base.

5. The flexible rotary eddy current inspection sensor for a heat transfer pipe of an evaporator of a nuclear power plant according to claim 1, characterized in that: the reference coil assembly comprises a reference coil body and nylon connecting pieces respectively fixed on two end parts of the reference coil body.

6. The flexible rotary eddy current inspection sensor for a heat transfer pipe of an evaporator of a nuclear power plant according to claim 1, characterized in that: the multi-core joint assembly comprises a multi-core joint body, a locking nut in threaded connection with the front end of the multi-core joint body, and a nylon connecting piece fixedly connected with the front end of the locking nut, and the rear end of the cable is fixedly connected with the nylon connecting piece of the multi-core joint assembly.

7. The flexible rotary eddy current inspection sensor for a heat transfer pipe of an evaporator of a nuclear power plant according to claim 1, characterized in that: the flexible connecting piece is a torsion spring, and the cable penetrates through the torsion spring.

8. The flexible rotary eddy current inspection sensor for a heat transfer pipe of an evaporator of a nuclear power plant according to claim 1, characterized in that: the functional assembly sequentially comprises a guide cone assembly, a planar coil assembly, an orthogonal coil assembly, a reference coil assembly and a multi-core joint assembly.

9. The nuclear power plant evaporator heat transfer tube flexible rotary eddy current inspection sensor according to claim 8, characterized in that: the functional assembly further comprises centering petals, and the centering petals are arranged between the guide cone assembly and the planar coil assembly and between the orthogonal coil assembly and the reference coil assembly.

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