Ultrasonic decontamination auxiliary device for pipeline hot spot of pressurized water reactor nuclear power station and use method of ultrasonic decontamination auxiliary device

Abstract

The invention relates to the technical field of pressurized water reactor nuclear power station pipeline hot spot ultrasonic decontamination, in particular to a pressurized water reactor nuclear power station pipeline hot spot ultrasonic decontamination auxiliary device and a using method. According to the scheme, through combination of the electric heater and the ultrasonic vibrator, hot spots of the pipeline are directly heated in the sealed cavity, ultrasonic vibration is generated, and the decontamination effect can be rapidly improved. Large-range energy waste is avoided through local heating, the device is suitable for pipelines of different specifications through the compact modular design, rapid disassembly and assembly are convenient, and the operation difficulty and the time cost are reduced. In addition, the multi-layer sealing design of the sealing ring and the sealing chamber is combined with the application of sealing silica gel, so that the sealing performance under high temperature and high pressure is ensured, and leakage of solution and heat is prevented. The ultrasonic vibrator enhances the chemical decontamination process, especially removal of stubborn corrosives, ensures thorough decontamination, and reduces residual radioactive substances. Due to the advantages, the device has wide application value.

Description

Technical Field

[0001] The invention relates to the technical field of hot spot ultrasonic decontamination of pipelines in a pressurized water reactor nuclear power plant, in particular to an auxiliary device for hot spot ultrasonic decontamination of pipelines in a pressurized water reactor nuclear power plant and a use method thereof. Background Art

[0002] During the maintenance of a pressurized water reactor nuclear power plant unit, in order to carry out equipment maintenance work, it is necessary to isolate the radioactive hot spots in the system and equipment. If the existence of hot spots affects the maintenance work, appropriate radioactive decontamination work needs to be carried out. Chemical decontamination is one of the methods.

[0003] Chemical decontamination uses the dissolving and stripping effects of chemical reagents to remove radioactive activated corrosion products deposited in the pipeline. The decontaminants used in chemical decontamination have high requirements for process temperature, and the general implementation temperature is between 85℃ and 95℃. If the temperature is too low, it is difficult to achieve the ideal decontamination effect, which will also lead to a long decontamination cycle and affect the maintenance of other equipment. In addition, industrial practice has also shown that ultrasound has an auxiliary effect on the chemical decontamination process of equipment.

[0004] During the chemical decontamination process of pipeline hot spots, a small cleaning device is usually connected, which has its own cleaning box and heating device. However, due to the excessive heat dissipation of the system caused by the temporary pipeline being too long, it is generally difficult to reach the process temperature at the hot spots of the pipeline. If an external heating facility is used to increase the temperature of the pipeline at the hot spots, it will greatly facilitate the chemical decontamination effect of the hot spots. At present, there is no similar local heating device Summary of the invention

[0005] In view of the above problems existing in the prior art, the present invention is proposed.

[0006] Therefore, the first purpose of the present invention is to propose a hot spot ultrasonic decontamination auxiliary device for pressurized water reactor nuclear power plant pipelines, which can solve the problem that the hot spots of the primary circuit chemical decontamination pipelines of pressurized water reactor nuclear power plants are difficult to reach the process temperature and the decontamination effect is unsatisfactory.

[0007] In order to solve the above technical problems, the present invention provides the following technical solutions: a hot spot ultrasonic decontamination auxiliary device for a pressurized water reactor nuclear power plant pipeline, which includes a sealing mechanism, including an axial sealing ring, an upper sealing chamber and a lower sealing chamber, the upper sealing chamber and the lower sealing chamber cover the outside of the pipeline, the axial sealing ring is arranged on the inner and outer sides of the upper sealing chamber and the lower sealing chamber, and the upper part of the upper sealing chamber is in an open state; a cleaning mechanism, including a heating element and a vibrating element, and the heating element and the vibrating element are arranged below the lower sealing chamber.

[0008] As a preferred solution of the hot spot ultrasonic decontamination auxiliary device for pressurized water reactor nuclear power plant pipelines described in the present invention, the upper sealing chamber and the lower sealing chamber have semicircular openings on the left and right sides respectively, and the openings match the outer wall of the axial sealing ring.

[0009] As a preferred solution of the hot spot ultrasonic decontamination auxiliary device for pressurized water reactor nuclear power plant pipelines described in the present invention, the axial sealing ring is divided into a first half ring and a second half ring, the first half ring and the second half ring are arranged on the outside of the pipeline and fastened by a fixed structure to form a connection with the upper sealing chamber and the lower sealing chamber.

[0010] As a preferred solution of the hot spot ultrasonic decontamination auxiliary device for pressurized water reactor nuclear power plant pipelines described in the present invention, wherein: the lower part of the upper sealing chamber and the upper part of the lower sealing chamber are both arranged with fastening bolt holes, and the sealing between the upper sealing chamber and the lower sealing chamber is achieved by fastening bolts.

[0011] As a preferred solution of the hot spot ultrasonic decontamination auxiliary device for pressurized water reactor nuclear power plant pipelines described in the present invention, the first half ring and the second half ring are located on the outside of the upper sealing chamber and the lower sealing chamber, and are fastened by steel tie bands.

[0012] As a preferred solution of the hot spot ultrasonic decontamination auxiliary device for pressurized water reactor nuclear power plant pipelines described in the present invention, the fixed structure includes a first sealing ring and a second sealing ring, the first sealing ring and the second sealing ring are located on the inner sides of the upper sealing chamber and the lower sealing chamber, are sleeved on the outer wall of the pipeline, and are fastened by steel tie bands.

[0013] As a preferred solution of the hot spot ultrasonic decontamination auxiliary device for pressurized water reactor nuclear power plant pipelines described in the present invention, one end of the axial sealing ring is processed with an external thread, and one end of the fixed structure is processed with an internal thread, which cooperates with the external thread of the axial sealing ring to clamp the two side surfaces of the upper sealing chamber and the lower sealing chamber.

[0014] As a preferred solution of the hot spot ultrasonic decontamination auxiliary device for pressurized water reactor nuclear power plant pipelines described in the present invention, the upper sealing chamber, the lower sealing chamber, the axial sealing ring, and the fixed structure are all made of stainless steel to ensure the rigidity of the material; the heating element is an electric heater, and the vibrating element is an ultrasonic vibrator.

[0015] Another object of the present invention is to propose a method for using a hot spot ultrasonic decontamination auxiliary device for a pressurized water reactor nuclear power plant pipeline, which includes the following steps: installing the upper sealing chamber and the lower sealing chamber on both sides of the pipeline respectively, and tightly connecting the sealing chamber and the pipeline through the axial sealing ring and the fixed structure to ensure the formation of a closed cavity; injecting desalted water into the chamber formed inside the upper sealing chamber and the lower sealing chamber; starting the heating element to control the temperature in the cavity to reach a preset requirement; starting the vibrating element to enhance the decontamination effect through ultrasonic vibration; after the decontamination process is completed, stopping heating and vibration, and removing the device.

[0016] As a preferred scheme for the method of using the hot spot ultrasonic decontamination auxiliary device for pressurized water reactor nuclear power plant pipelines described in the present invention, when the device is started, a 2% citric acid + 0.1% EDTA decontamination solution is injected into the pipeline to chemically decontaminate the hot spots in the pipeline, and the effects of the heating element and the vibrating element are utilized to enhance the decontamination effect inside the pipeline.

[0017] The beneficial effects of the present invention are as follows: This solution directly heats the hot spots of the pipeline in the sealed cavity and generates ultrasonic vibrations through the combination of an electric heater and an ultrasonic vibrator, which can quickly improve the decontamination effect. Local heating avoids large-scale energy waste, and through a compact modular design, the device is suitable for pipelines of different specifications, which is convenient and quick to disassemble and assemble, reducing the difficulty of operation and time cost. In addition, the multi-layer sealing design of the sealing ring and the sealing chamber combined with the application of sealing silicone ensures the sealing performance under high temperature and high pressure, and prevents the leakage of solutions and heat. The ultrasonic vibrator enhances the chemical decontamination process, especially the removal of stubborn corrosives, ensures the thoroughness of the decontamination, and reduces residual radioactive substances. These advantages make the device have a wide range of application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. Among them:

[0019] Figure 1 This is a structural diagram of the hot spot ultrasonic decontamination auxiliary device for pressurized water reactor nuclear power plant pipelines.

[0020] Figure 2 A step-by-step diagram of the use of the hot spot ultrasonic decontamination auxiliary device for pressurized water reactor nuclear power plant pipelines DETAILED DESCRIPTION

[0021] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings.

[0022] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0023] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor is it an embodiment that is mutually exclusive with other embodiments, either individually or selectively.

[0024] Example 1

[0025] Reference Figure 1 , which is the first embodiment of the present invention, and provides a hot spot ultrasonic decontamination auxiliary device for a pressurized water reactor nuclear power plant pipeline, including: a sealing mechanism 100, including an axial sealing ring 101, an upper sealing chamber 102 and a lower sealing chamber 103, the upper sealing chamber 102 and the lower sealing chamber 103 cover the outside of the pipeline, the axial sealing ring 101 is arranged on both sides of the upper sealing chamber 102 and the lower sealing chamber 103, and the upper part of the upper sealing chamber 102 is in an open state; a cleaning mechanism 200, including a heating element 201 and a vibrating element 202, the heating element 201 and the vibrating element 202 are arranged below the lower sealing chamber 103;

[0026] The sealing mechanism 100 fixes the entire device to the outside of the pipeline through the axial sealing ring, the upper sealing chamber and the lower sealing chamber to form a closed cavity to prevent leakage of solution or gas during the decontamination process; the axial sealing ring 101 provides additional sealing and support to ensure that the upper and lower sealing chambers are stable and do not fall off during operation; the upper sealing chamber 102 is designed with an opening to facilitate installation and exhaust, and at the same time cooperates with the lower sealing chamber to form a closed structure; the combination of the heating element 201 and the vibrating element 202 ensures the increase in the surface temperature of the pipeline, and at the same time enhances the decontamination effect through vibration.

[0027] The close combination of the axial sealing ring and the upper and lower sealing chambers not only achieves the external sealing effect, but also enhances the stability of the equipment under high temperature and vibration working conditions. This structural design not only realizes the decontamination function, but also improves the durability of the equipment in complex environments, avoids the leakage of the solution outside the pipeline, thereby ensuring work efficiency and reducing the frequency of equipment maintenance.

[0028] Example 2

[0029] Reference Figure 1 , which is the second embodiment of the present invention, and this embodiment is based on the previous embodiment.

[0030] Specifically, the upper sealing chamber 102 and the lower sealing chamber 103 have semicircular openings 106 on the left and right sides respectively, and the openings 106 match the outer wall of the axial sealing ring 101; this opening design enables the sealing chamber to be easily wrapped on the pipeline and at the same time match the outer wall of the axial sealing ring, thereby enhancing the sealing performance and reducing the difficulty of installation.

[0031] Specifically, the axial sealing ring 101 is divided into a first half ring 101a and a second half ring 101b. The first half ring 101a and the second half ring 101b are arranged outside the pipeline and fastened by a fixing structure 104 to form a connection with the upper sealing chamber 102 and the lower sealing chamber 103.

[0032] The design of the two half rings makes it easy to wrap around the outside of the pipe during installation, and lock it firmly through the fixing structure to form a stable connection;

[0033] It is worth noting that the axial sealing ring 101 has a variety of different specifications, and each specification of the axial sealing ring 101 has the same outer diameter and a different inner diameter to match pipes of different diameters, and the outer diameter is the same.

[0034] Specifically, fastening bolt holes 105 are arranged at the lower part of the upper sealing chamber 102 and the upper part of the lower sealing chamber 103, and the sealing between the upper sealing chamber 102 and the lower sealing chamber 103 is achieved by fastening bolts 102a;

[0035] The upper and lower sealing chambers are fixed by bolts, which further enhances the sealing of the device and ensures the stability of the cavity during heating and vibration.

[0036] Specifically, the first half ring 101a and the second half ring 101b are located outside the upper sealed chamber 102 and the lower sealed chamber 103, and are fastened by steel tie straps; the steel tie straps further ensure the fixation of the first half ring and the second half ring, increasing the overall stability and vibration resistance of the system.

[0037] Specifically, the fixing structure 104 includes a first sealing ring 104a and a second sealing ring 104b, the first sealing ring 104a and the second sealing ring 104b are located inside the upper sealing chamber 102 and the lower sealing chamber 103, are sleeved on the outer wall of the pipeline, and are fastened by a steel tie;

[0038] The design of two sealing rings ensures the sealing performance between the inside of the device and the pipeline, further preventing leakage; through the close cooperation between the sealing ring and the steel tie, not only efficient sealing performance is achieved, but also the vibration resistance of the equipment is enhanced, so that the device can remain sealed and leak-proof during ultrasonic vibration, while reducing the loss of heat and decontamination solution, and improving the working stability of the device.

[0039] Specifically, one end of the axial sealing ring 101 is processed with an external thread 101c, and one end of the fixing structure 104 is processed with an internal thread 104c, which cooperates with the external thread of the axial sealing ring 101 to clamp the two side surfaces of the upper sealing chamber 102 and the lower sealing chamber 103;

[0040] The design of the external thread and the internal thread enhances the fixing force between the sealing chambers, further improving the stability and external force resistance of the sealing chambers; the axial sealing ring 101 and the fixing structure 104 seal the left and right sides of the upper sealing chamber 102) and the lower sealing chamber 103 with the pores of the pipeline.

[0041] Specifically, the upper sealing chamber 102, the lower sealing chamber 103, the axial sealing ring 101, and the fixed structure 104 are all made of stainless steel to ensure the rigidity of the material; the heating element 201 is an electric heater, and the vibrating element 202 is an ultrasonic vibrator;

[0042] The use of stainless steel ensures the rigidity and durability of the device under high temperature and high pressure conditions; the coordinated work of the electric heater and ultrasonic vibrator in a high temperature environment improves the thoroughness of the internal decontamination process of the pipeline. This design accelerates the stripping of corrosion products and reduces the decontamination time through vibration-assisted heating.

[0043] Example 3

[0044] Reference Figure 2 , which is the third embodiment of the present invention, and this embodiment provides a method for using a hot spot ultrasonic decontamination auxiliary device for a pressurized water reactor nuclear power plant pipeline, comprising the following steps: installing an upper sealing chamber 102 and a lower sealing chamber 103 on both sides of the pipeline respectively, and tightly connecting the sealing chamber and the pipeline through an axial sealing ring 101 and a fixing structure 104 to ensure that a closed cavity is formed; injecting desalted water into the chamber formed inside the upper sealing chamber 102 and the lower sealing chamber 103; starting the heating element 201 to control the temperature in the cavity to reach a preset requirement; starting the vibrating element 202 to enhance the decontamination effect through ultrasonic vibration; after the decontamination process is completed, stopping heating and vibration, and removing the device.

[0045] Specifically, when the device is started, a 2% citric acid + 0.1% EDTA decontamination solution is injected into the pipeline to chemically decontaminate the hot spots in the pipeline, and the effects of the heating element 201 and the vibrating element 202 are utilized to enhance the decontamination effect inside the pipeline.

[0046] When in use, first install the axial sealing ring 101. Before installing the axial sealing ring 101, apply sealing silicone on the surface of the pipeline. After the axial sealing ring 101 is fixed on the pipeline, use a steel tie to fasten the two half rings of the axial sealing ring 101. Then, fix the upper sealing chamber 102 and the lower sealing chamber 103 on the axial sealing ring 101 through the fastening bolts 102a, and apply sealing silicone on the contact part of the axial sealing ring 101 with the upper sealing chamber 102 and the lower sealing chamber 103. Then combine the first sealing ring 104a and the second sealing ring 104b, put them on the outer wall of the pipeline, and then fasten them with a steel tie. Finally, match them with the external thread of the axial sealing ring 101, clamp the two sides of the upper sealing chamber 102 and the lower sealing chamber 103, and apply sealing silicone on the contact part of the axial sealing ring 101 with the side of the upper sealing chamber 102 and the lower sealing chamber 103. After the device is installed, inject deionized water into the chamber formed inside the upper sealing chamber 102 and the lower sealing chamber 103. A 2% citric acid + 0.1% EDTA decontamination solution is injected into the pipeline through a temporary chemical decontamination system to chemically decontaminate the hot spots in the pipeline. The electric heater and ultrasonic vibrator at the bottom of the lower sealed chamber 103 are started to make the desalted water temperature in the chamber formed inside the upper sealed chamber 102 and the lower sealed chamber 103 reach 90°C.

[0047] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A hot spot ultrasonic decontamination auxiliary device for pipelines of a pressurized water reactor nuclear power plant, characterized in that: include, The sealing mechanism (100) comprises an axial sealing ring (101), an upper sealing chamber (102) and a lower sealing chamber (103), wherein the upper sealing chamber (102) and the lower sealing chamber (103) cover the outside of the pipeline, the axial sealing ring (101) is arranged on both the inner and outer sides of the upper sealing chamber (102) and the lower sealing chamber (103), and the upper part of the upper sealing chamber (102) is in an open state; The cleaning mechanism (200) comprises a heating element (201) and a vibrating element (202), wherein the heating element (201) and the vibrating element (202) are arranged below the lower sealed chamber (103).

2. The hot spot ultrasonic decontamination auxiliary device for pipelines of a pressurized water reactor nuclear power plant according to claim 1, characterized in that: The upper sealing chamber (102) and the lower sealing chamber (103) are respectively provided with semicircular openings (106) on the left and right sides, and the openings (106) match the outer wall of the axial sealing ring (101).

3. The hot spot ultrasonic decontamination auxiliary device for pipelines of a pressurized water reactor nuclear power plant according to claim 2, characterized in that: The axial sealing ring (101) is divided into a first half ring (101a) and a second half ring (101b); the first half ring (101a) and the second half ring (101b) are arranged outside the pipeline and fastened by a fixing structure (104) to form a connection with the upper sealing chamber (102) and the lower sealing chamber (103).

4. The hot spot ultrasonic decontamination auxiliary device for pipelines of a pressurized water reactor nuclear power plant according to claim 3, characterized in that: The lower part of the upper sealing chamber (102) and the upper part of the lower sealing chamber (103) are both provided with fastening bolt holes (105), and the sealing between the upper sealing chamber (102) and the lower sealing chamber (103) is achieved by fastening bolts (102a).

5. The hot spot ultrasonic decontamination auxiliary device for pipelines of a pressurized water reactor nuclear power plant according to claim 4, characterized in that: The first half ring (101a) and the second half ring (101b) are located outside the upper sealed chamber (102) and the lower sealed chamber (103), and are fastened by steel cable ties.

6. The hot spot ultrasonic decontamination auxiliary device for pipelines of a pressurized water reactor nuclear power plant according to claim 5, characterized in that: The fixing structure (104) comprises a first sealing ring (104a) and a second sealing ring (104b), wherein the first sealing ring (104a) and the second sealing ring (104b) are located on the inner sides of the upper sealing chamber (102) and the lower sealing chamber (103), are sleeved on the outer wall of the pipeline, and are fastened by a steel tie.

7. The hot spot ultrasonic decontamination auxiliary device for pipelines of a pressurized water reactor nuclear power plant according to claim 6, characterized in that: One end of the axial sealing ring (101) is processed with an external thread (101c), and one end of the fixing structure (104) is processed with an internal thread (104c) which cooperates with the external thread of the axial sealing ring (101) to clamp the two side surfaces of the upper sealing chamber (102) and the lower sealing chamber (103).

8. The hot spot ultrasonic decontamination auxiliary device for pipelines of a pressurized water reactor nuclear power plant according to claim 7, characterized in that: The upper sealing chamber (102), the lower sealing chamber (103), the axial sealing ring (101), and the fixing structure (104) are all made of stainless steel to ensure the rigidity of the material; The heating element (201) is an electric heater, and the vibrating element (202) is an ultrasonic vibrator.

9. A method for using a hot spot ultrasonic decontamination auxiliary device for a pressurized water reactor nuclear power plant pipeline, applicable to the hot spot ultrasonic decontamination auxiliary device for a pressurized water reactor nuclear power plant pipeline according to any one of claims 1 to 8, characterized in that: include: The upper sealing chamber (102) and the lower sealing chamber (103) are respectively installed on both sides of the pipeline, and the sealing chamber is tightly connected to the pipeline through the axial sealing ring (101) and the fixing structure (104) to ensure that a closed cavity is formed; Injecting deionized water into the chamber formed inside the upper sealed chamber (102) and the lower sealed chamber (103); Starting the heating element (201) to control the temperature in the cavity to reach a preset requirement; activating the vibrating member (202) to enhance the decontamination effect through ultrasonic vibration; When the decontamination process is complete, stop heating and vibration and remove the device.

10. The method for using the hot spot ultrasonic decontamination auxiliary device for pipelines of a pressurized water reactor nuclear power plant according to claim 9, characterized in that: When the device is started, a 2% citric acid + 0.1% EDTA decontamination solution is injected into the pipeline to chemically decontaminate the hot spots in the pipeline, and the effects of the heating element (201) and the vibrating element (202) are utilized to enhance the decontamination effect inside the pipeline.

Images