A fixed bracket for measuring neutron temperature in core nuclear measurement

Abstract

The present invention belongs to the field of mechanical design technology, and specifically relates to a fixed bracket used for a core nuclear neutron temperature measurement channel. The present invention is used to fix the neutron temperature measurement channel, including a vertical bracket top, a vertical support rod, and a lower base; the vertical bracket top is connected to the lower base through a vertical support rod, the vertical bracket is used to fix the neutron temperature measurement channel, and the lower base is installed on a hole on a transport platform. The present invention can reduce unnecessary eye-to-eye processes, and the upper hard tube portion of the neutron temperature measurement channel is fixed in three layers, which can make it easier to fix the neutron temperature measurement channel, saving time and effort.

Description

Technical Field

[0001] The invention belongs to the technical field of mechanical design, and in particular relates to a fixing bracket used for a neutron temperature measurement channel of a core nuclear measurement. Background Art

[0002] The core nuclear measurement system is used for monitoring the local linear power density of the reactor core and the core power field distribution. The core nuclear measurement system of some nuclear power plants involves the protection of the reactor. When the parameters exceed the allowable value, a protection signal will be generated and sent to the reactor protection system. It plays a very important role in the instrumentation and control system of the nuclear power plant.

[0003] The on-site instrument of the core nuclear measurement system is the neutron temperature measurement channel. There are 54 channels in a single unit, which are installed in the reserved holes of the fuel assemblies respectively. They are used to monitor the neutron flux density (power density), coolant inlet and outlet, the temperature of the lower part of the pressure top cover, the coolant level and other functions. The total length is nearly 13 meters, and it is immersed in the reactor coolant for nearly 12 meters. The upper 1m of the neutron temperature measurement channel is a hard tube, and the lower nearly 12 meters is a soft tube. When the neutron temperature measurement channel is pulled out, it mainly fixes the upper 1m of the hard tube.

[0004] Due to the need for refueling during overhaul, the neutron temperature measurement channel needs to be pulled out and fixed on the transport platform. After the refueling is completed, it is reinstalled from the transport platform into the fuel assembly. In order to ensure the reliable fixation of the neutron temperature measurement channel during this period, it is necessary to consider the fixing method of the neutron temperature measurement channel on the transport platform.

[0005] The transport platform is designed with 18 holes (including a personnel passage) reserved for the extraction and installation of neutron temperature measurement channels. Each hole can be used for the installation and removal of three neutron temperature measurement channels. In the early stage, according to the Russian design, the method adopted was to use thin ropes to tie and fix them on the first layer of fence of the transport platform.

[0006] When the existing neutron temperature measurement channel fixing bracket is used, the channel is first at the bottom of the core (the third platform), and is finally manually pulled into the small round hole of the transport platform (the first platform), and then fixed with the bracket. Moreover, the three neutron temperature measurement channels are pulled up and fixed together. After pulling up, the bracket needs to be inserted into the middle of the three channels, and then the three neutron temperature measurement channels are aligned with the three holes of the bracket. The neutron temperature measurement channel itself is heavy, which has a great impact on the alignment process. Accurate alignment is difficult and time-consuming.

[0007] This patent is designed and developed to address the above situation. It is a fixed bracket used for the neutron temperature measurement channel of the core nuclear measurement. It adopts a parallel socket method to reduce unnecessary eye alignment, and the upper hard tube part of the neutron temperature measurement channel is fixed in three layers, which can make it easier to fix the neutron temperature measurement channel and save time and effort. Summary of the invention

[0008] The purpose of the present invention is to provide a fixing bracket for a neutron temperature measuring channel of a core nuclear measurement, which adopts a parallel socket method and is directly inserted from the side. The base is directly seated in a platform mounting hole, thereby reducing unnecessary eye alignment processes. In addition, a three-layer fixing is performed on the upper hard tube portion of the neutron temperature measuring channel, which can make it easier to fix the neutron temperature measuring channel and save time and effort.

[0009] The technical solution adopted by the present invention is:

[0010] A fixing bracket used for a core nuclear measurement neutron temperature measurement channel is used to fix the neutron temperature measurement channel, comprising a vertical bracket top, a vertical support rod, and a lower base; the vertical bracket top is connected to the lower base through the vertical support rod, the vertical bracket is used to fix the neutron temperature measurement channel, and the lower base is installed on a hole on a transport platform.

[0011] The top of the vertical bracket includes a clamp and a connecting rod. The connecting rod has a T-shaped structure. A clamp is installed on each of the three end points of the T-shaped connecting rod. The clamp is used to fix and pull out the neutron temperature measurement channel. The T-connecting part of the connecting rod is provided with a mounting hole for installing the vertical support rod.

[0012] The lower base is a circular steel plate structure, including a vertical support rod mounting hole and a fork. A vertical support rod mounting hole is provided at the center of the circle of the lower base for mounting the vertical support rod. Three forks with the same opening direction are opened on the lower base.

[0013] The three forks are parallel, and the opening distance of the forks is greater than the bottom hose diameter of the neutron temperature measurement channel; the port positions of the forks correspond to the position of the clamp.

[0014] Three steel arc blocks are distributed in a circular pattern on the lower part of the base between the three forks, and the arrangement of the steel arc blocks will not obstruct the forks; the cylinder composed of the steel arc blocks is used to cooperate with the holes reserved on the transport platform.

[0015] The three fork ends are all reserved with neutron temperature measurement channel mounting holes, and the mounting holes are the same size as the diameter of the hollow cylinder at the bottom of the neutron temperature measurement channel, which is convenient for the installation of the neutron temperature measurement channel. At the same time, the size of the mounting hole is also smaller than the diameter of the large cylinder at the upper channel of the neutron temperature measurement channel, and the hollow cylinder at the bottom of the hard tube part of the neutron temperature measurement channel is just stuck in the mounting hole.

[0016] A semicircular boss is arranged above the mounting hole, the opening direction of the boss is consistent with the fork opening, and the opening is consistent with the fork opening in size.

[0017] A sliding block is provided inside the fork opening, a fastening device is provided on the sliding block, and the sliding block slides to a certain position and passes through the fastening device.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] The present invention provides a fixing bracket for a neutron temperature measuring channel of a core nuclear measurement. The fixing bracket can be directly inserted at an angle during the pulling out process of the neutron temperature measuring channel, and then installed in a hole of a platform. The problem of channel damage caused by interlacing and winding during the pulling out process of the neutron temperature measuring channel can be prevented, and the eye alignment process is no longer required. The neutron temperature measuring channel can be fixed three times, saving time and effort. The inconvenience of using the existing bracket is well solved. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 :Three-dimensional schematic diagram of the fixed bracket for the transport platform of the neutron temperature measurement channel

[0021] Figure 2 :Schematic diagram of the bottom bracket structure of the fixed bracket of the neutron temperature measurement channel transportation platform

[0022] Figure 3 : Schematic diagram of the top of the vertical bracket

[0023] Figure 4 :Schematic diagram of the boss structure

[0024] Figure 5 :Schematic diagram of the bottom of the neutron temperature measurement channel

[0025] In the figure: 1-vertical bracket, 2-vertical support rod, 3-lower base, 4-clamp, 5-connecting rod, 6-mounting hole, 7-steel arc block, 8-boss, 9-mounting hole, 10-vertical support rod mounting hole, 11-fork, 12-fastening device, 13-slider, 14-arc slider; 15-locking clamp, 101 inverted frustum; 102 hollow cylinder; 103 large channel cylinder. DETAILED DESCRIPTION

[0026] The following is a further detailed description of a fixing bracket for measuring the neutron temperature of a core nuclear measurement provided by the present invention in conjunction with the accompanying drawings and specific embodiments.

[0027] like Figure 1 As shown, the present invention provides a fixing bracket for a core nuclear neutron temperature measurement channel, which is used to fix the neutron temperature measurement channel. The neutron temperature measurement channel has a structure as shown in FIG. Figure 5As shown, it includes an inverted truncated table 101, a hollow cylinder 102, and a large channel cylinder 103. The fixed bracket includes a top of a vertical bracket 1, a vertical support rod 2, and a lower base 3. The top of the vertical bracket 1 is connected to the lower base 3 through the vertical support rod 2. The vertical bracket 1 is used to fix the fixture 4 and is in the same vertical line as the fork on the lower base 3. It can fix the neutron temperature measurement channel without generating torque.

[0028] The lower base 3 is installed on the hole on the transport platform. The three semi-arc blocks at the bottom of the lower base 3 are slightly smaller than the hole, and the plate surface of the lower base 3 covers the hole.

[0029] like Figure 2 As shown, the top of the vertical support 1 includes a clamp 4 and a connecting rod 5. The connecting rod 5 has a T-shaped structure. A clamp 4 is installed on each of the three ends of the T-shaped connecting rod 5. The clamp 4 is used to fix and pull out the neutron temperature measurement channel; the T-connecting portion of the connecting rod 5 is provided with a mounting hole 6 for mounting the vertical support rod 2;

[0030] like Figure 3 As shown, the lower base 3 is a circular steel plate structure, including a steel arc block 7, a boss 8, a mounting hole 9, a vertical support rod mounting hole 10, a fork 11, a fastening device 12, and a slider 13. A vertical support rod mounting hole 10 is provided at the center of the circular steel plate for installing the vertical support rod 2; the fixed bracket is made of steel, which is cheap and has good stability, and can effectively fix the neutron temperature measurement channel on the transportation platform.

[0031] The circular steel plate has three forks 11 with the same opening direction, and the port position of the fork 11 corresponds to the position of the clamp 4.

[0032] The three forks 11 are parallel, and the opening distance of the forks 11 is greater than the bottom hose diameter of the neutron temperature measurement channel; three steel arc blocks 7 are distributed in a circular pattern on the lower part of the base between the forks, and the setting of the steel arc will not hinder the forks; the cylinder composed of the steel arc blocks 7 is used to cooperate with the holes reserved on the transport platform.

[0033] The circle formed by the steel arc block 7 is slightly smaller than the hole of the transport platform, so that the fixed bracket can be firmly installed in the hole of the platform when it is installed;

[0034] Neutron temperature measurement channel mounting holes 9 are reserved at the ends of the three forks 11. The mounting holes 9 are the same size as the diameter of the hollow cylinder 102 at the bottom of the neutron temperature measurement channel, which is convenient for the installation of the neutron temperature measurement channel. At the same time, the size of the mounting hole is also smaller than the diameter of the large cylinder 103 at the upper part of the neutron temperature measurement channel. The hollow cylinder 102 at the bottom of the hard tube of the neutron temperature measurement channel is just stuck in the mounting hole. A semicircular boss 8 is arranged above the mounting hole, the opening direction of the boss 8 is consistent with the fork 11, and the opening is consistent with the fork 11 in size. The bottom of the neutron temperature measurement channel is an inverted cone 101, and there is a hollow cylinder 102 on the inverted cone 101. Above the hollow cylinder 102 is a large channel cylinder 103. The height from the boss to the mounting hole is higher than the height of the large channel cylinder 103. When the neutron temperature measurement channel is installed in place, under the influence of gravity, the large channel cylinder 103 of the neutron temperature measurement channel will be just stuck on the boss and the large channel cylinder 103 is supported on this steel plate to prevent running.

[0035] A slider 13 is provided inside the fork opening 11 , and a fastening device 12 is provided on the slider 13 . The slider 13 slides to a certain position and passes through the fastening device 12 .

[0036] A slide is provided at the center of the side wall of the boss 8, an arc-shaped slider is provided inside the slide, and a locking clamp is provided at the end of the slider. After the bottom of the hard tube portion of the neutron temperature measurement channel is seated on the boss three, the sliding slider surrounds the neutron temperature measurement channel and is fixed by the locking clamp to play a secondary fixing role; as shown in the figure, a slide groove is provided at the upper edge of the mounting hole on the supporting circular steel plate, a slider is slidably provided in the slide groove, and a fastening device is provided at the end of the slider. When the hollow cylinder 102 is seated in the mounting hole, the slider is pushed so that the slider just blocks the fork, and the hollow cylinder 102 is locked by the fastening device to facilitate fixing; it plays a tertiary fixing role.

[0037] After this fixed bracket is put into use, during the overhaul of the unit, the neutron temperature measurement channels will not be intertwined or collide with each other when being pulled out to the transportation platform, and there is no need for eye-to-eye operation, which greatly reduces the maintenance time and saves time and effort.

[0038] During the overhaul of the unit, the fixed bracket achieved the purpose of fixing the neutron temperature measurement channel firmly and orderly on the transport platform. It was supported by a steel base, and three neutron temperature measurement channels in the same transport platform hole were installed by using the reserved holes of the base and the upper parallel openings. The existing hole size of the transport platform was cleverly used to complete the design of the stable installation of the neutron temperature measurement channel. This scheme has a good reference significance for the neutron temperature measurement channel that needs to be fixed on the transport platform during the overhaul of the unit. By changing the base, the support rod and the fork, and then fixing it with a clamp, the installation and fixation of the neutron temperature measurement channel on the transport platform can be better guaranteed.

[0039] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the art who, within the technical scope disclosed by the present invention, makes equivalent substitutions or changes based on the technical scheme and inventive concept of the present invention should be covered within the protection scope of the present invention.

Claims

1. A fixing bracket for a core nuclear neutron temperature measurement channel, used to fix the neutron temperature measurement channel, characterized in that: It includes a vertical bracket top, a vertical support rod, and a lower base; the vertical bracket top is connected to the lower base through the vertical support rod, the vertical bracket is used to fix the neutron temperature measurement channel, and the lower base is installed on the hole on the transport platform; the vertical bracket top includes a clamp and a connecting rod, the connecting rod has a T-shaped structure, and a clamp is respectively installed on the three end points of the T-shaped connecting rod, and the clamp is used to fix and pull out the neutron temperature measurement channel; the T-connecting part of the connecting rod is provided with a mounting hole for installing the vertical support rod; the lower base is a circular steel plate structure, including a vertical support rod mounting hole and a fork, a vertical support rod mounting hole is provided at the center of the circle of the lower base for installing the vertical support rod, and three forks with the same opening direction are opened on the lower base; three steel arc blocks are distributed in a circular pattern on the lower part of the base between the three forks, and the setting of the steel arc blocks will not hinder the fork; the cylinder composed of steel arc blocks is used to cooperate with the holes reserved on the transport platform; The three forks are parallel, and the opening distance of the forks is greater than the bottom hose diameter of the neutron temperature measurement channel; the port position of the forks corresponds to the position of the clamp; The three fork ends are all reserved with neutron temperature measurement channel mounting holes, and the mounting holes are the same size as the diameter of the hollow cylinder at the bottom of the neutron temperature measurement channel, which is convenient for the installation of the neutron temperature measurement channel. At the same time, the size of the mounting hole is also smaller than the diameter of the large cylinder at the upper channel of the neutron temperature measurement channel, and the hollow cylinder at the bottom of the hard tube part of the neutron temperature measurement channel is just stuck in the mounting hole.

2. The fixing bracket for measuring the neutron temperature of a core according to claim 1 is characterized in that: A semicircular boss is arranged above the mounting hole, the opening direction of the boss is consistent with the fork opening, and the opening is consistent with the fork opening in size.

3. The fixing bracket for measuring the neutron temperature of a core according to claim 1 is characterized in that: A sliding block is provided inside the fork opening, a fastening device is provided on the sliding block, and the sliding block slides to a certain position and passes through the fastening device.

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