A reactor neutron temperature measurement channel flange transportation device

Abstract

The present application belongs to the technical field of nuclear power plant reactor maintenance, and specifically relates to a reactor neutron temperature measurement channel flange transportation device; the device includes: a basket and a lifting lug fixed to the upper edge of the basket; the basket is a double-layer structure, the outer layer is a metal frame of a basket-shaped structure, and the inner layer is a non-metallic lining for accommodating the neutron temperature measurement channel flange; the lifting lug is used to lift and transport the basket. On the basis of ensuring sufficient structural strength, the overall weight is greatly reduced, which is convenient for staff to carry or adjust the position of the empty transportation device; the inner layer is made of lightweight non-metallic material, which effectively protects the flange sealing surface and other weak parts from accidental damage.

Description

Technical Field

[0001] The present application belongs to the technical field of nuclear power plant reactor maintenance, and specifically relates to a reactor neutron temperature measurement channel flange transportation device. Background Art

[0002] As an important part of the reactor, the upper assembly is mainly used to seal the main sealing surface of the reactor, form a dense internal space of the reactor, establish a certain pressure, and prevent the internal components of the reactor from floating up under the action of the core water flow. At the same time, the upper assembly plays the role of fixing the control rod drive mechanism and its electrical equipment, fixing the core instrument sensor line terminals and seals. There are 141 pipes arranged on the top cover of the upper assembly, including 18 neutron temperature measurement channel pipes, and the top of the pipes are all provided with lower flanges for sealing. The 54 neutron temperature measurement channels distributed in the core are combined into 18 groups of neutron temperature measurement tube bundles with 3 measurement channels in each group, which are distributed to the 18 neutron temperature measurement channel pipes on the top cover of the upper assembly. The upper flange cooperates with the lower flange to achieve sealing with the pipe. This seal belongs to the primary circuit pressure boundary.

[0003] The sealing structure of the neutron temperature measurement channel includes two types of seals: the seal between the lower flange and the upper flange of the top cover pipe and the seal between the upper flange and the three neutron temperature measurement tubes. The lower flange and the upper flange of the top cover pipe are connected by 6 bolts. Two different types of inner and outer graphite gaskets are arranged between the upper and lower flanges. The sealing is achieved by tightening 6 nuts to compress the two graphite gaskets. A leakage monitoring pipeline is set between the inner and outer gaskets. The sealing structure of the upper flange of the neutron temperature measurement channel pipe and the three neutron temperature measurement tubes mainly includes: a pair of metal half rings, a short sleeve, a graphite gasket, a short sleeve, a graphite gasket, a long sleeve, and a nut. The sealing is achieved by compressing the graphite gasket with a nut with an external thread. The sealing structure of the neutron temperature measurement channel is complex, and multiple sealing surfaces and threaded sections are distributed on the upper flange. Protecting its outer dimensions and the integrity of each sealing surface will directly affect the sealing reliability of the neutron temperature measurement channel.

[0004] During the overhaul of refueling and dismantling, the 18 sets of neutron temperature measurement channel pipes were unsealed in the dismantling stage according to the overhaul regulations, and the upper flanges were removed and hoisted to the reactor hall for cleaning, inspection and storage. During the installation stage, the cleaned and inspected upper flanges were hoisted to the upper component work area in the reactor shaft to reinstall and seal the neutron temperature measurement channel. During the unsealing and sealing process of the neutron temperature measurement channel, the removed upper flanges are generally temporarily stored on the maintenance work platform, and the upper flanges are hoisted to the reactor hall by a cantilever crane. Due to the lack of a dedicated storage container, the small maintenance work platform, the dense personnel, the numerous maintenance tools and the frequent use of various objective factors, there have been many incidents of the upper flange falling to the +24m platform of the reactor shaft and being damaged, and the tools hitting the upper flange sealing surface, making the upper flange unusable, causing great economic losses and posing great industrial safety risks. In addition, the lack of a dedicated transport container means that only one upper flange can be lifted at a time, and the lifting efficiency is extremely low. On the one hand, it affects the unsealing and sealing work time of the neutron temperature measurement channel, and on the other hand, it invisibly increases the possibility of damage to the upper flange. Summary of the invention

[0005] The purpose of this application is to provide a reactor neutron temperature measurement channel flange transportation device to solve the problem of lack of special storage and transportation containers for neutron temperature measurement channel flanges in the prior art, improve the safety and work efficiency of neutron temperature measurement channel flange transportation work, reduce the industrial safety risks of this work, and avoid unnecessary equipment damage and economic loss incidents.

[0006] Technical solution to achieve the purpose of this application:

[0007] The embodiment of the present application provides a reactor neutron temperature measurement channel flange transportation device, the device comprising: a basket and a lifting lug fixed to the upper edge of the basket;

[0008] The basket is a double-layer structure, the outer layer is a metal frame of a basket-shaped structure, and the inner layer is a non-metallic lining for accommodating the neutron temperature measurement channel flange;

[0009] The lifting lugs are used for lifting and transporting the basket.

[0010] Optionally, a basket edge is welded to the upper end surface of the metal frame, and the four corners of the basket edge are welded to the lifting ears;

[0011] A reinforcing rib is welded to the outer surface of the side plate of the metal frame, and the upper end surface of the reinforcing rib is welded to the basket edge.

[0012] Optionally, the lining fits the metal frame, and no relative displacement occurs between the two;

[0013] The upper end surface of the lining is flush with the upper end surface of the basket edge.

[0014] Optionally, the lower end surface of the lining is provided with a countersunk hole corresponding to the protruding portion of the lower part of the flange of the neutron temperature measurement channel;

[0015] The depth of the countersunk hole is greater than the height of the protruding portion at the lower portion of the flange of the neutron temperature measurement channel.

[0016] Optionally, guide columns are provided on the bosses at both ends of the countersunk hole for inserting into the light holes for installing the flange bolts of the neutron temperature measurement channel.

[0017] Optionally, the upper end of the guide column is a conical structure.

[0018] Optionally, the guide column and the lining are connected by threads.

[0019] Optionally, a pin hole is provided on the guide column, and the distance between the pin hole and the boss is greater than the height of the light hole;

[0020] The metal frame and the lining are both provided with through holes corresponding to the pin holes; an anti-drop pin shaft is installed in the through hole;

[0021] One end of the anti-dropout pin shaft is provided with a handle larger than the through hole, the handle is located outside the metal frame, and the other end of the anti-dropout pin shaft is inserted into the pin hole.

[0022] Optionally, a return spring is sleeved on the guide column, and a boss is provided on the guide column;

[0023] One end of the return spring is fixed to the housing, and the other end is clamped on the boss; when the guide post is pulled out of the pin hole, the return spring is compressed.

[0024] Optionally, the basket is used to accommodate a plurality of the neutron temperature measurement channel flanges.

[0025] The beneficial technical effects of this application are:

[0026] (1) A reactor neutron temperature measurement channel flange transport device provided in an embodiment of the present application adopts a double-layer structure design, which greatly reduces the overall weight while ensuring sufficient structural strength, making it convenient for workers to carry or adjust the position of the empty transport device; the inner layer is made of lightweight non-metallic material, which effectively protects the flange sealing surface and other weak parts from accidental damage;

[0027] (2) A reactor neutron temperature measurement channel flange transportation device provided in an embodiment of the present application cleverly utilizes the light hole of the neutron temperature measurement channel flange itself and sets a guide column for use therewith to realize the rapid loading or unloading of the flange into or out of the transportation device, while limiting the movement of the flange in the transportation device. The device fully considers the possible accidental situations such as the breakage of the sling during the lifting of the transportation device, and sets an effective anti-slip and anti-falling device to ensure the safety of the transportation of the neutron temperature measurement channel flange.

[0028] (3) The reactor neutron temperature measurement channel flange transportation device provided in the embodiment of the present application adopts a detachable and replaceable connection method for vulnerable parts that are prone to wear and change during long-term use, thereby ensuring the service life of the transportation device. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 A schematic structural diagram of a reactor neutron temperature measurement channel flange transportation device provided in an embodiment of the present application;

[0030] Figure 2 A top view of a reactor neutron temperature measurement channel flange transportation device provided in an embodiment of the present application;

[0031] Figure 3 A cross-sectional view of a flange storage position of a reactor neutron temperature measurement channel flange transportation device provided in an embodiment of the present application;

[0032] Figure 4 A schematic diagram of centering and dropping of a neutron temperature measurement channel flange of a reactor neutron temperature measurement channel flange transportation device provided in an embodiment of the present application;

[0033] Figure 5 A schematic diagram of the installation of a neutron temperature measurement channel flange of a reactor neutron temperature measurement channel flange transportation device provided in an embodiment of the present application.

[0034] In the figure:

[0035] 1-basket; 11-metal frame; 12-lining, 121-countersunk hole, 122-shoulder; 13-basket edge; 14-reinforcement rib; 15-guide column, 151-pin hole, 152-boss; 16-through hole; 17-anti-drop pin shaft, 171-handle; 18-reset spring;

[0036] 2-Lifting lugs;

[0037] 3- neutron temperature measurement channel flange; 31- protruding portion; 32- light hole; 33- carrying handle. DETAILED DESCRIPTION

[0038] In order to make those skilled in the art better understand the present application, the technical scheme in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the embodiments described below are only a part of the embodiments of the present application, not all. Based on the embodiments recorded in the present application, all other embodiments obtained by those skilled in the art without paying creative work are within the scope of protection of the present application.

[0039] The inventors of the present application have found in their research that, based on the particularity of the structure of the neutron temperature measurement channel flange and the importance of its function, and taking into account objective factors such as on-site maintenance conditions and work flow, the following technical requirements are proposed for the design of the neutron temperature measurement channel flange transportation device: (1) The neutron temperature measurement channel flange transportation device should have sufficient structural strength, but at the same time should be as light as possible to ensure that it can be carried manually when unloaded; (2) Effective measures should be taken to prevent damage to the sealing surface of the portion of the transportation device that contacts the sealing surface of the neutron temperature measurement channel flange; (3) The neutron temperature measurement channel flange can be quickly and conveniently loaded or unloaded in the transportation device without large-scale movement in the transportation device; (4) The transportation device should have a suitable flange loading capacity; (5) The neutron temperature measurement channel flange should have effective anti-slip measures in the transportation device to prevent the flange from falling out of the transportation device due to accidents such as sling breakage during transportation.

[0040] To this end, a neutron temperature measurement channel flange transportation device provided in the present application adopts the following technical solutions in design to meet the above technical requirements: (1) The transportation device adopts an inner and outer double-layer structure, the outer metal frame ensures the overall structural strength, and the inner layer of lightweight non-metallic materials greatly reduces the overall weight; (2) The inner layer of lightweight non-metallic materials effectively protects the flange sealing surface from damage; (3) A guide column is provided, which cooperates with the light hole for mounting bolts on the flange, so that the flange can be quickly loaded into or removed from the transportation device, and the movement of the flange in the transportation device is limited; (4) According to the number of unsealing or sealing of a single neutron temperature measurement channel (such as 2-3 groups), considering the rationality of the placement of the transportation device on the on-site work surface, the transportation basket can accommodate up to 3 neutron temperature measurement channel flanges; (5) An anti-drop pin is provided at the upper end of the guide column to prevent the flange from falling out of the transportation device.

[0041] Based on the above content, in order to clearly and in detail illustrate the above advantages of the present application, the specific implementation methods of the present application will be described below in conjunction with the accompanying drawings.

[0042] See also Figure 1 and Figure 2 , which is a structural schematic diagram and top view of a reactor neutron temperature measurement channel flange transportation device provided in an embodiment of the present application.

[0043] A reactor neutron temperature measurement channel flange transportation device provided in an embodiment of the present application comprises: a basket 1 and a lifting lug 2 fixed to the upper edge of the basket 1;

[0044] The basket 1 is a double-layer structure, the outer layer is a metal frame 11 of a basket-shaped structure, and the inner layer is a non-metallic lining 12, which is used to accommodate the neutron temperature measurement channel flange 3;

[0045] The lifting lug 2 is used for lifting and transporting the basket 1 .

[0046] In the embodiment of the present application, according to the particularity of the neutron temperature measurement channel flange structure and the importance of its function, a neutron temperature measurement channel flange transportation device is developed to address the problems existing in the flange storage and transportation process, filling the gap of the lack of special tools for this work, and utilizing a basket 1 to accommodate the neutron temperature measurement channel flange 3, and utilizing the lifting lug 2 to transport the basket 1 carrying the neutron temperature measurement channel flange 3, thereby avoiding the risks during the maintenance process.

[0047] It can be understood that the basket 1 adopts a double-layer structure design, which greatly reduces the overall weight while ensuring sufficient structural strength, making it convenient for staff to carry or adjust the position of the empty transport device; the inner layer adopts a lightweight non-metallic material lining 12 to effectively protect the flange sealing surface and other weak components from accidental damage.

[0048] In a specific implementation, the outer metal frame 11 can be a metal frame structure with a rectangular appearance. The thickness of the plate is selected based on the load-bearing weight and a suitable safety factor, so as to reduce the overall weight as much as possible while ensuring the structural strength.

[0049] In practical applications, the housing 1 is used to accommodate multiple neutron temperature measurement channel flanges 3. For example, according to the number of unsealing or sealing of a single neutron temperature measurement channel (such as 2-3 groups), and considering the rationality of the placement of the transport device on the on-site work surface, the housing 1 can accommodate up to three neutron temperature measurement channel flanges 3, such as Figure 1 and Figure 2 shown.

[0050] In some possible implementations of the embodiments of the present application, a basket edge 13 is welded to the upper end surface of the metal frame 11, and lifting ears 2 are welded at the four corners of the basket edge 13, which serve as lifting points for lifting and transporting the neutron temperature measurement channel flange transportation device; reinforcing ribs 14 are welded to the outer surface of the side plates of the metal frame 11, and the upper end surfaces of the reinforcing ribs 14 are welded to the basket edge 13.

[0051] It is understandable that the basket edge 13 can increase the transverse strength of the outer metal frame 11 to prevent the neutron temperature measurement channel flange transportation device from being greatly deformed during long-term use. The reinforcing ribs 14 increase the longitudinal strength of the outer metal frame 11 to prevent the neutron temperature measurement channel flange transportation device from being greatly deformed during long-term use.

[0052] In one example, the lining 12 is placed in the metal frame 11 and fits the metal frame 11 , and no relative displacement occurs between the two; the upper end surface of the lining 11 is flush with the upper end surface of the basket edge 13 .

[0053] In some possible implementations of the present application, in order to prevent the flange from moving in the transport device, such as Figure 3-5 As shown, the lower end surface of the lining 12 is provided with a countersunk hole 121 corresponding to the lower protruding portion 31 of the neutron temperature measurement channel flange 3;

[0054] The depth of the countersunk hole 121 is greater than the height of the lower protruding portion 31 of the neutron temperature measurement channel flange 3. The lower end surface of the neutron temperature measurement channel flange 3 is supported on the boss 122 of the liner 12. The lower protruding portion 31 of the flange is inserted into the countersunk hole 121, so that the two important sealing surfaces of the neutron temperature measurement channel flange 3 can be shielded and protected to prevent damage to the sealing surfaces.

[0055] In some possible implementations of the embodiments of the present application, guide posts 15 are provided on the bosses 122 at both ends of the counterbore 121 for inserting into the light holes 32 for bolt installation of the neutron temperature measurement channel flange 3 .

[0056] It can be understood that the guide column 15 plays a guiding role in the process of installing the neutron temperature measurement channel flange 3 into the housing 1, ensuring that the neutron temperature measurement channel flange 3 is quickly and accurately seated on the boss 122 of the liner 12 while the protruding portion 31 at the lower part of the neutron temperature measurement channel flange 3 is inserted into the counterbore 121. The guide column 15 also limits the position of the neutron temperature measurement channel flange 3 in the housing 11 so that it does not undergo a large radial displacement, thereby playing a good fixing role.

[0057] As an example, two bolt holes are symmetrically opened on both sides of each countersunk hole 121 for installing the guide column 15 , and the guide column 15 is connected to the liner 12 by threading.

[0058] In specific implementation, the guide column 15 will inevitably deform and wear after long-term use, resulting in deterioration of the guiding effect until it is unusable. Therefore, the guide column 15 is connected to the liner 12 by a threaded connection so that the guide column 15 is detachable and replaceable and managed as a consumable part.

[0059] In one example, the upper end of the guide column 15 is a tapered structure, so that the light hole 32 for bolt installation of the neutron temperature measurement channel flange 3 can quickly engage with the guide column 15, achieving a better guiding effect.

[0060] In some possible implementations of the present application, a pin hole 151 is provided on the guide column 15 , and the distance between the pin hole 151 and the boss 122 is greater than the height of the light hole 32 ;

[0061] The metal frame 11 and the lining 12 are both provided with a through hole 16 corresponding to the pin hole 151; an anti-drop pin shaft 17 is installed in the through hole 16;

[0062] One end of the anti-dropout pin shaft 17 is provided with a handle 171 larger than the through hole 16 , and the handle 171 is located outside the metal frame 11 . The other end of the anti-dropout pin shaft 17 is inserted into the pin hole 151 .

[0063] It can be understood that the anti-drop pin 17 passes through the metal frame 11 and the lining 12, connecting the two as a whole. The head of the anti-drop pin 17 is inserted into the pin hole 151 of the same elevation on the guide column 15, limiting the upward displacement of the neutron temperature measurement channel flange 3, preventing the flange 3 from falling out of the basket 11 due to accidents such as the breakage of the sling during transportation, and playing an effective anti-drop effect. One end of the anti-drop pin 17 is a handle 171, which is used to manually pull the anti-drop pin 17 out of the pin hole 151 to open the falling channel when the neutron temperature measurement channel flange 3 is loaded into the transport basket.

[0064] In one example, a return spring 18 is sleeved on the guide post 15 , and a boss 152 is provided on the guide post 15 ;

[0065] One end of the return spring 18 is fixed to the housing 1 , and the other end is clamped on the boss 152 ; when the guide post 15 is pulled out of the pin hole, the return spring 18 is compressed.

[0066] It can be understood that the anti-dropout pin shaft 17 is inserted into the guide column 15 at the elastic action portion of the return spring 18, thereby playing an effective anti-dropout role.

[0067] The following is a detailed description of a specific method for using a reactor neutron temperature measurement channel flange transportation device provided in an embodiment of the present application, with reference to a specific example.

[0068] See also Figure 4 , 5 The method for using a reactor neutron temperature measurement channel flange transportation device provided in an embodiment of the present application is as follows:

[0069] (1) Initial status inspection of the neutron temperature measurement channel flange transport device: Check the appearance of the metal frame 11, the lifting lug 2 and the welds for crack damage; check that all guide pillars 15 are not loose, have smooth surfaces without burrs and other defects, and have no obvious axial deformation; check that all anti-drop pins 17 are moving normally and can be reset freely;

[0070] (2) Use a shackle and a lifting strap to connect the lifting lug 2 to the hook of the on-site cantilever crane, slowly lift the hook so that the transport basket is 100 mm off the ground, and adjust the lifting strap so that the transport device is visually level;

[0071] (3) Continue to hoist the neutron temperature measurement channel flange transport device to the upper assembly maintenance platform in the reactor shaft for storage, and disconnect the lifting belt from the cantilever crane hook;

[0072] (4) On-site staff perform the unsealing work of the neutron temperature measurement channel. Install the flange carrying handle 33 in the threaded hole in the center of the disassembled neutron temperature measurement channel flange 3, and lift the neutron temperature measurement channel flange 3 to the top of the basket 1. Use the handle 171 to pull out the two anti-drop pins 17 to open the channel for the neutron temperature measurement channel flange 3 to fall. Align any two symmetrical bolt installation holes 32 of the neutron temperature measurement channel flange 3 with the guide column 15, and slowly lower it until it sits on the boss 122 of the liner 12. Loosen the handle 171, and the anti-drop pin 17 is inserted into the pin hole 151 under the action of the reset spring 18 to play an anti-drop function;

[0073] (5) After the three neutron temperature measurement channel flanges 3 are filled, the lifting belt is reconnected to the hook of the cantilever crane, and the neutron temperature measurement channel flange transportation device is lifted to the reactor hall, and the neutron temperature measurement channel flange 3 is taken out to perform subsequent cleaning and inspection work. Before the next group of workers performs the unsealing work of other neutron temperature measurement channels, repeat the above steps to complete the temporary storage and transportation of the neutron temperature measurement channel flange 3.

[0074] The reactor neutron temperature measurement channel flange transportation device provided in the embodiment of the present application solves the problems existing in the storage and transportation process of the neutron temperature measurement channel flange, improves the safety and work efficiency of the neutron temperature measurement channel flange transportation work, reduces the industrial safety risks of the work, and avoids unnecessary equipment damage and economic loss events. This project can be promoted and applied in related work of the same type of units.

[0075] The reactor neutron temperature measurement channel flange transportation device provided in the embodiment of the present application can be extended to the storage and transportation of other similar equipment in power plants, and also has good reference significance for the storage and transportation of other similar equipment in the same industry.

[0076] The present application is described in detail above in conjunction with the accompanying drawings and embodiments, but the present application is not limited to the above embodiments, and various changes can be made within the knowledge of ordinary technicians in the field without departing from the purpose of the present application. Any content not described in detail in the present application can adopt the existing technology.

Claims

1. A reactor neutron temperature measurement channel flange transportation device, characterized in that: The device comprises: a basket and a hanging ear fixed to the upper edge of the basket; The basket is a double-layer structure, the outer layer is a metal frame of a basket-shaped structure, and the inner layer is a non-metallic lining for accommodating the neutron temperature measurement channel flange; The lifting lugs are used for lifting and transporting the basket; The lower end surface of the lining is provided with a countersunk hole corresponding to the protruding portion of the lower part of the flange of the neutron temperature measurement channel; The depth of the countersunk hole is greater than the height of the protruding portion of the lower portion of the flange of the neutron temperature measurement channel; Guide columns are arranged on the bosses at both ends of the countersunk hole for inserting into the light holes for bolt installation of the flange of the neutron temperature measurement channel; the upper end of the guide column is a conical structure.

2. The reactor neutron temperature measurement channel flange transportation device according to claim 1, characterized in that: A basket edge is welded on the upper end surface of the metal frame, and the four corners of the basket edge are welded with the lifting ears; A reinforcing rib is welded to the outer surface of the side plate of the metal frame, and the upper end surface of the reinforcing rib is welded to the basket edge.

3. The reactor neutron temperature measurement channel flange transportation device according to claim 2, characterized in that: The lining fits the metal frame, and there is no relative displacement between the two; The upper end surface of the lining is flush with the upper end surface of the basket edge.

4. The reactor neutron temperature measurement channel flange transportation device according to claim 1, characterized in that: The guide column and the liner are connected by threading.

5. The reactor neutron temperature measurement channel flange transportation device according to claim 1, characterized in that: A pin hole is provided on the guide column, and the distance between the pin hole and the boss is greater than the height of the light hole; The metal frame and the lining are both provided with through holes corresponding to the pin holes; an anti-drop pin shaft is installed in the through hole; One end of the anti-dropout pin shaft is provided with a handle larger than the through hole, the handle is located on the outside of the metal frame, and the other end of the anti-dropout pin shaft is inserted into the pin hole.

6. The reactor neutron temperature measurement channel flange transportation device according to claim 1, characterized in that: A return spring is sleeved on the guide column, and a boss is provided on the guide column; One end of the return spring is fixed to the housing, and the other end is clamped on the boss; when the guide post is pulled out of the light hole, the return spring is compressed.

7. The reactor neutron temperature measurement channel flange transportation device according to any one of claims 1 to 6, characterized in that: The basket is used to accommodate a plurality of neutron temperature measurement channel flanges.

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