Spiral feeding device capable of absorbing thermal displacement and nuclear fuel conversion system

Abstract

The invention belongs to the technical field of nuclear fuel conversion, and particularly relates to a spiral feeding device capable of absorbing thermal displacement and a nuclear fuel conversion system. The device is installed at an inlet of a reactor barrel and comprises a blowing mechanism, the blowing mechanism comprises an inclined feeding part and a horizontal feeding part arranged on one side of the top of the inclined feeding part, and the bottom end of the inclined feeding part is fixedly connected with the inlet of the reactor barrel through a first flange assembly; the spiral feeding mechanism is arranged on the side, away from the inclined feeding part, of the horizontal feeding part and connected with the horizontal feeding part through a corrugated pipe connecting mechanism. Compared with the prior art, the device has the advantages that the problems of material blocking, outlet deviation and the like caused by deformation of equipment due to the influence of temperature are avoided, the influence of thermal displacement is reduced, the stable proceeding of the feeding process is ensured, the maintenance and inspection frequency of the system is reduced, and the operation cost of the equipment is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of nuclear fuel conversion, and in particular relates to a spiral feeding device capable of absorbing thermal displacement and a nuclear fuel conversion system. Background Art

[0002] In the nuclear fuel conversion system, a screw feeder is used to transport materials into the main reactor. The screw feeder must ensure good sealing performance between the main reactor and the material conveying equipment to prevent gas leakage in the main reactor. Specifically, the screw feeder should have an effective sealing structure and sealing technology to meet the strict requirements of the nuclear fuel conversion system for gas sealing.

[0003] The return material dissolution and feeding device used for nuclear fuel assembly production in the prior art includes a barrel 70, the lower end of the barrel 70 is connected to a discharge bin 71, the lower end of the discharge bin 71 is connected to a feed screw 72, a reducer 73 is connected to the feed screw 72 to provide power to the feed screw 72, the right end of the feed screw 72 is connected to a discharge connecting pipe 74, the upper end of the discharge connecting pipe 74 is provided with an upper cover 75, and the lower end of the discharge connecting pipe 74 is connected to a dissolution column feed port 76.

[0004] Combined with Figure 6 It can be seen that the feeding device is connected to the nuclear combustion reactor through the feeding screw to provide fuel to the reactor. However, due to the high operating temperature of the reactor and the long overall structure, when the temperature of the equipment changes due to the reaction, the reactor barrel will be heated and elongated, which will cause thermal displacement between the reactor barrel and the feeding screw, causing the feeding position to shift, thus affecting the feeding.

[0005] Based on this, the present invention provides a spiral feeding device and a nuclear fuel conversion system that can absorb thermal displacement to overcome the above-mentioned defects. Summary of the invention

[0006] One object of the present invention is to provide a spiral feeding device that can absorb thermal displacement, which avoids the deformation of the equipment due to temperature and causes problems such as material jamming and outlet deviation, reduces the impact of thermal displacement, ensures a smooth feeding process, reduces the number of system maintenance inspections, and reduces equipment operating costs.

[0007] The present invention adopts the following technical solutions:

[0008] A spiral feeding device capable of absorbing thermal displacement, installed at the inlet of a reactor cylinder, comprises:

[0009] A blowing mechanism, the blowing mechanism comprising an inclined feeding portion and a horizontal feeding portion arranged on one side of the top of the inclined feeding portion, wherein the bottom end of the inclined feeding portion is fixedly connected to the inlet of the reactor cylinder through a first flange assembly;

[0010] A spiral feeding mechanism, the spiral feeding mechanism is arranged on a side of the horizontal feeding portion away from the inclined feeding portion, and is connected to the horizontal feeding portion through a bellows connecting mechanism;

[0011] Wherein, the bellows connection mechanism comprises a bellows and a straight pipe member, the straight pipe member comprises a left straight pipe and a right straight pipe, the left straight pipe and the right straight pipe are respectively arranged at the left and right ends of the bellows; and a first flange is arranged at the outer ends of the left straight pipe and the right straight pipe;

[0012] The spiral feeding mechanism includes a feeding sleeve and a spiral rotating shaft. The feeding sleeve is inserted and installed into the horizontal feeding part of the blowing mechanism along the bellows connecting mechanism, and a second flange is arranged on the outer wall of the feeding sleeve. The second flange is connected to the first flange at the outer end of the right straight pipe; the spiral rotating shaft is inserted and installed in the feeding sleeve.

[0013] Furthermore, a nitrogen blowing feeding mechanism is fixedly installed on the top of the inclined feeding part.

[0014] Furthermore, the nitrogen blowing feeding mechanism comprises:

[0015] An end cover, the end cover is mounted on the top of the inclined feeding part;

[0016] A nitrogen blowing pipe extends from the end cover into the inclined feed portion.

[0017] Furthermore, two nitrogen blowing pipes are provided, one extending to the bottom end close to the inclined feed portion, and the other extending to the outlet close to the horizontal feed portion.

[0018] Furthermore, an external feed pipe is fixedly installed at the inlet of the reactor cylinder, the external feed pipe is sleeved on the outer wall of the bottom end of the inclined feed part, and the top end of the external feed pipe is fixedly connected to the inclined feed part through a first flange assembly.

[0019] Furthermore, the reactor barrel is connected to the bottom end of the external feed pipe by welding.

[0020] Furthermore, the bottom end of the inclined feed pipe is in an oblique cone shape.

[0021] Furthermore, a pressure sensor and a temperature sensor are installed in the feed sleeve.

[0022] Furthermore, at least one annular sealing groove is provided on an end surface of one flange in the first flange assembly, and an annular protrusion matching the annular sealing groove is formed on an end surface of another flange in the first flange assembly, and the annular protrusion is placed in the annular sealing groove;

[0023] And / or, at least one annular sealing groove is provided on the end surface of the first flange or the second flange, and an annular protrusion matching the annular sealing groove is formed on the end surface of the second flange or the first flange, and the annular protrusion is placed in the annular sealing groove. Compared with the prior art, the present invention has the following beneficial effects:

[0024] The spiral feeding device capable of absorbing thermal displacement in the present invention is in operation. During the nuclear fuel conversion process, the material first enters the spiral feeding mechanism, which pushes the material forward by its own rotational motion. The spiral feeding mechanism is connected to the horizontal feeding part of the blowing mechanism through a bellows connection mechanism. The horizontal feeding part plays a transition and guiding role, guiding the material to the inclined feeding part. Due to its inclined structure, the inclined feeding part can utilize gravity and the flow inertia of the material to smoothly introduce the material into the reactor cylinder.

[0025] At the same time, during the nuclear fuel conversion process, the temperature change of the reactor cylinder may cause its length to change, resulting in thermal displacement between the blowing mechanism and the spiral feeding mechanism. At this time, the bellows connection mechanism can adapt to this change through its own elastic deformation, avoiding damage to the connection parts of the device or poor material transportation such as jamming due to thermal displacement, thereby improving the reliability and stability of the device. For example, when the reactor cylinder is deformed by heat, a small displacement along the axis of the cylinder will occur, and the horizontally arranged bellows connection mechanism can not only absorb the axial installation error, but also absorb the small lateral error or displacement, so this thermal displacement can be completely absorbed by the bellows. On the other hand, the bellows connection mechanism is connected between the blowing mechanism and the spiral feeding mechanism, which not only ensures that the original material transfer function remains unchanged, but also ensures that the entire device has a certain sealing performance to prevent harmful gases from leaking through the blowing device; and reduces the number of maintenance inspections of the system, reducing the equipment operation cost.

[0026] In addition, the inclined feed portion is fixedly connected to the inlet of the reactor cylinder through the first flange assembly, ensuring the firmness and sealing of the connection, so that the material can accurately and stably enter the reactor cylinder for nuclear fuel conversion reaction. Accordingly, the rigid connection of the flange assembly can fix the angle of the blowing mechanism, ensure that the angle between the blowing mechanism and the furnace axis remains unchanged, and avoid angular displacement of the blowing mechanism.

[0027] The second object of the present invention is to provide a nuclear fuel conversion system, which includes the above-mentioned spiral feeding device capable of absorbing thermal displacement. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. 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 paying creative work.

[0029] Figure 1 This is a schematic diagram of the overall structure of a spiral feeding device capable of absorbing thermal displacement according to a specific embodiment of the present invention;

[0030] Figure 2 for Figure 1 Schematic diagram of the structure of the middle blowing mechanism;

[0031] Figure 3 for Figure 1 Schematic diagram of the structure of the middle bellows connection mechanism;

[0032] Figure 4 for Figure 1 Schematic diagram of the structure of the spiral feeding mechanism;

[0033] Figure 5 for Figure 1 Schematic diagram of the local structure;

[0034] Figure 6 It is a schematic diagram of the structure of a return material dissolving and feeding device used in the production of nuclear fuel assemblies in the prior art;

[0035] Wherein: reactor barrel 1, external feed pipe 10; blowing mechanism 2, inclined feed part 20, horizontal feed part 21; first flange assembly 3; spiral feeding mechanism 4, feed sleeve 40, second flange 401, spiral shaft 41; bellows connecting mechanism 5, bellows 50, left straight pipe 51, right straight pipe 52, first flange 53; nitrogen blowing feeding mechanism 6, end cover 60, nitrogen blowing pipe 61; barrel 70, unloading silo 71, feed screw 72, reducer 73, unloading connecting pipe 74, upper cover 75, dissolution column feed port 76; annular sealing groove 8; annular protrusion 9. DETAILED DESCRIPTION

[0036] The following will be combined with the accompanying drawings in the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work belong to the protection scope of the present invention.

[0037] The following is combined with Figure 1 To Attachment Figure 5 And specific embodiments, the present invention is described in detail:

[0038] like Figure 1-5 As shown, the present invention provides a spiral feeding device capable of absorbing thermal displacement, which is mainly used in the field of nuclear fuel conversion, and can also be extended to be applied to process systems with thermal displacement between the input end and the output end, and can adapt to high temperature and toxic medium conditions. The spiral feeding device is installed at the inlet of the reactor barrel 1, and includes a blowing mechanism 2 and a spiral feeding mechanism 4.

[0039] Among them, the blowing mechanism 2 includes an inclined feed part 20 and a horizontal feed part 21 arranged on one side of the top of the inclined feed part 20, and the whole presents a similar "r"-shaped structure; the bottom end of the inclined feed part 20 is fixedly connected to the entrance of the reactor barrel 1 through the first flange assembly 3. In this embodiment, the first flange assembly 3 is composed of two relatively arranged flanges, and the two flanges are fixedly connected by bolts, and the connection method is simple and reliable. The bottom end of the inclined feed pipe 20 is in an oblique cone shape. The oblique cone design makes the caliber of the bottom end of the feed pipe gradually narrow, which can guide the material and ensure that the position of the material falling and conveying meets the requirements. Under the action of gravity and the flow inertia of the material itself, the material is more likely to flow to the entrance of the reactor barrel 1, reducing the risk of retention and blockage of the material in the feed pipe, and ensuring the smoothness of material transportation. At the same time, the oblique cone shape can speed up the flow rate of the material. As the diameter gradually decreases, the material is compressed to a certain extent during the flow process, thereby increasing the flow speed of the material and improving the material transportation efficiency, so that the material can enter the reactor cylinder 1 faster and meet the continuous feeding requirements of the nuclear fuel conversion process.

[0040] The spiral feeding mechanism 4 is disposed on a side of the horizontal feeding portion 21 away from the inclined feeding portion 20 , and is connected to the horizontal feeding portion 21 via a bellows connecting mechanism 5 .

[0041] When the spiral feeding device capable of absorbing thermal displacement is in operation, during the nuclear fuel conversion process, the material first enters the spiral feeding mechanism 4, which pushes the material forward by its own rotational motion. The spiral feeding mechanism 4 is connected to the horizontal feeding part 21 of the blowing mechanism 2 through the bellows connecting mechanism 5, and the horizontal feeding part 21 plays a transition and guiding role, guiding the material to the inclined feeding part 20. Due to its inclined structure, the inclined feeding part 20 can use gravity and the flow inertia of the material to smoothly introduce the material into the reactor cylinder 1.

[0042] At the same time, during the nuclear fuel conversion process, the temperature change of the reactor barrel 1 may cause its length to change, resulting in thermal displacement between the blowing mechanism 2 and the spiral feeding mechanism 4. At this time, the bellows connection mechanism 5 can adapt to this change through its own elastic deformation, avoiding damage to the connection part of the device or poor material transportation such as jamming due to thermal displacement, thereby improving the reliability and stability of the device. For example, when the reactor barrel 1 is deformed by heat, a small downward displacement along the axis of the barrel will occur, and the horizontally arranged bellows connection mechanism 5 can not only absorb the axial installation error, but also absorb the small lateral error or displacement, so this thermal displacement can be completely absorbed by the bellows. On the other hand, the bellows connection mechanism 5 is used to connect the blowing mechanism 2 and the spiral feeding mechanism 4, which not only ensures that the original material transfer function remains unchanged, but also ensures that the entire device has a certain sealing performance to prevent harmful gases from leaking through the blowing device; and reduces the number of maintenance inspections of the system, reducing the equipment operation cost.

[0043] In addition, the inclined feed portion 20 is fixedly connected to the inlet of the reactor barrel 1 through the first flange assembly 3, ensuring the firmness and sealing of the connection, so that the material can accurately and stably enter the reactor barrel 1 for nuclear fuel conversion reaction. Accordingly, the rigid connection of the flange assembly can fix the angle of the blowing mechanism 2, ensure that the angle between the blowing mechanism 2 and the furnace axis remains unchanged, and avoid angular displacement of the blowing mechanism 2.

[0044] Among them, Figure 1 , 3 As shown, the bellows connection mechanism 5 includes a bellows 50 and a straight pipe.

[0045] The bellows 50 has good elastic deformation capability. During the nuclear fuel conversion process, when the reactor barrel 1 changes in temperature and causes the length to change, the bellows 50 can adapt to the thermal displacement between the blowing mechanism 2 and the spiral feeding mechanism 4 through its own expansion and contraction deformation, thereby avoiding damage to the connection parts due to thermal stress and ensuring the reliability and stability of the device. Meanwhile, the bellows 50 is usually made of metal or other elastic materials.

[0046] The straight pipe member includes a left straight pipe 51 and a right straight pipe 52, which are respectively arranged at the left and right ends of the bellows 50; and first flanges 53 are welded at the outer ends of the left straight pipe 51 and the right straight pipe 52, which are respectively used to be fixedly connected to the horizontal feed part 21 of the blowing mechanism 2 and the spiral feed mechanism 4. The first flanges 53 are arranged at both ends of the straight pipe member, and the flange connection mode has the advantages of firm connection and convenient disassembly, which can ensure the stability of the bellows connection mechanism 5 during the material transfer process.

[0047] like Figure 1 , 2As shown, the spiral feeding mechanism 4 includes a feeding sleeve 40 and a spiral rotating shaft 41. The feeding sleeve 40 is inserted and installed into the horizontal feeding part 21 of the blowing mechanism 2 along the bellows connecting mechanism 5, and a second flange 401 is welded on the outer wall of the feeding sleeve 40, and the second flange 401 is connected to the first flange 53 at the outer end of the right straight pipe 52; it should be noted that when the first flange 53 and the second flange 401 are connected, the sealing of the connection part can be enhanced by installing a sealing gasket or using a sealant. The tightness and rigidity of the flange connection can effectively prevent the leakage of harmful gases through the bellows connecting mechanism 5. The feeding sleeve 40 can be made of a material with a certain strength and corrosion resistance to adapt to the working environment in the field of nuclear fuel conversion. It should be noted that when designing the length and diameter of the feed sleeve 40, it is necessary to comprehensively consider the diameter of the horizontal feed portion 21 of the blowing mechanism 2 and the gap at the intersection of the inclined feed portion 20 and the horizontal feed portion 21, and leave enough gap to ensure that after the reactor barrel 1 is thermally deformed, there is no collision between the feed sleeve 40 and the blowing mechanism 2.

[0048] The spiral shaft member 41 is inserted and installed in the feed sleeve 40. The spiral shaft member 41 can be connected to an external power source through a coupling or other transmission device to drive the spiral shaft member 41 to rotate and push the material forward. Preferably, the spiral shaft member 41 is made of high-strength, wear-resistant material to ensure that it can withstand the friction of the material and the driving torque of the external power source during long-term operation. The surface of the spiral shaft member 41 is treated for smoothness and hardness to improve its surface hardness and smoothness, reduce the adhesion of materials on it, and improve the material transportation efficiency.

[0049] The feed sleeve 40 is connected to the right straight pipe 52 of the bellows connection mechanism 5 and the horizontal feed portion 21 of the blowing mechanism 2 to form a stable material transmission channel. The second flange 401 welded on its outer wall is tightly connected to the first flange 53 at the outer end of the right straight pipe 52, which enhances the sealing of the connection part, effectively prevents the leakage of harmful gases, and also improves the structural stability of the entire device.

[0050] In some more specific embodiments, the feed sleeve 40 needs to extend into the horizontal feed portion 21 of the blowing mechanism 2, close to the inclined feed portion 20 of the blowing mechanism 2, to prevent the material from falling into the bellows 50 of the bellows connecting mechanism 5 and damaging the bellows 50. The accumulation of material in the bellows may change the elastic properties of the bellows, affect its ability to absorb thermal displacement, and may even cause the bellows to be blocked, affecting the normal transportation of materials. If the elasticity of the bellows is affected, during the nuclear fuel conversion process, when the temperature of the reactor barrel changes, the bellows may not be able to effectively absorb the thermal displacement, resulting in damage to the connection part of the device or poor material transportation. By preventing the material from falling into the bellows, the elastic properties of the bellows can be maintained, ensuring the stable operation of the device in a thermally changing environment.

[0051] Further, in some specific embodiments, such as Figure 1 As shown, a nitrogen blowing feeding mechanism 6 is fixedly installed on the top of the inclined feeding part 20, which can blow nitrogen to blow the materials gathered in the inclined feeding part 20 into the reactor barrel 1. The nitrogen blowing feeding mechanism 6 includes an end cover 60 and a nitrogen blowing pipe 61.

[0052] The end cover 60 is installed on the top of the inclined feed part 20; specifically, the end cover 60 can be fixedly installed on the top of the inclined feed part 20 through a flange assembly, so that the end cover 60 can be fixedly installed to avoid relative displacement between the nitrogen blowing feed mechanism 6 and the reactor barrel 1. At the same time, the flange assembly connection has the advantages of convenient and quick disassembly and replacement; the end cover 60 is covered on the top of the inclined feed part 20 and is fixedly installed through the flange assembly, which can provide good sealing performance, prevent external impurities, dust, moisture, etc. from entering the inclined feed part, ensure the purity of the material during transportation, and avoid adverse effects on the nuclear fuel conversion process.

[0053] The nitrogen blowing pipe 61 extends from the end cover 60 into the inclined feed part 20. In this embodiment, two nitrogen blowing pipes 61 are provided, one extending to the bottom end near the inclined feed part 20, and the other extending to the outlet near the horizontal feed part 21, so that the gathered materials are blown to the outlet at the bottom end of the inclined feed part 20 by air pressure. During the material conveying process, nitrogen can be blown into the inclined feed part 20, and the nitrogen gas flow can be used to promote the flow of materials, thereby improving the conveying efficiency and speed of materials. The flow of nitrogen can reduce the risk of accumulation and blockage of materials in the inclined feed part 20, and ensure that the materials smoothly enter the reactor barrel 1. At the same time, in the field of nuclear fuel conversion, some materials may have the characteristics of being flammable and easily oxidized. Blowing in nitrogen can form an inert atmosphere in the inclined feed part 20, reduce the chance of contact between materials and oxygen, prevent oxidation and combustion of materials, and improve the safety of the equipment. In addition, nitrogen is introduced to achieve nitrogen sealing, thereby preventing corrosive gases from entering the gap between the external feed pipe 10 and the blowing mechanism 2, and further avoiding corrosion of the flange, etc.

[0054] In summary, the design of the nitrogen blowing feed mechanism 6 can improve the performance and reliability of the screw feed device and provide better material conveying and processing conditions for the nuclear fuel conversion process.

[0055] It should be noted that in actual use, for certain nuclear fuels, heated nitrogen can be introduced into the nitrogen blowing pipe 61 of the nitrogen blowing feeding mechanism 6 for heating or preheating the fuel. By blowing in heated nitrogen to heat or preheat the nuclear fuel, heat can be more evenly distributed in the nuclear fuel. Compared with the traditional direct heating method, nitrogen as a heat transfer medium can better contact with the nuclear fuel, reduce the risk of local overheating, and thus improve the uniformity of heating. And the heated nitrogen can quickly transfer heat to the nuclear fuel, thereby shortening the heating or preheating time and improving production efficiency. In addition, due to the good heat transfer performance of nitrogen, energy consumption can be reduced and production costs can be reduced.

[0056] Furthermore, in some specific embodiments, Figure 1 As shown, an external feed pipe 10 is fixedly installed at the inlet of the reactor cylinder 1. It should be noted that there are many ways to implement the external feed pipe 10 fixedly installed at the inlet of the reactor cylinder 1, such as welding, flange connection, etc. In this embodiment, the reactor cylinder 1 is welded to the bottom end of the external feed pipe 10, which is simple to implement and has good connection reliability.

[0057] At the same time, the outer feed pipe 10 is sleeved on the outer wall of the bottom end of the inclined feed part 20, and its inner diameter is slightly larger than the outer diameter of the inclined feed part 20, so that the bottom end of the inclined feed part 20 can be smoothly inserted into the outer feed pipe 10. The top end of the outer feed pipe 10 is connected to the middle part of the inclined feed part 20 through the first flange assembly 3, so as to realize the fixed connection between the outer feed pipe 10 and the inclined feed part 20 of the blowing mechanism 2. In order to ensure the sealing of the connection, a sealing gasket can also be installed between the flanges of the first flange assembly 3. The sealing gasket is made of high temperature resistant and corrosion resistant materials, which can effectively prevent material leakage and external gas from entering the reactor barrel 1.

[0058] First, the outer feed pipe 10 is sleeved on the outer wall at the bottom end of the inclined feed part 20 and fixedly connected by the first flange assembly. This design provides double connection guarantees. On the one hand, the sleeve of the outer feed pipe 10 increases the contact area of ​​the connection and improves the stability of the connection; on the other hand, the use of the first flange assembly 3 makes the connection more firm and reliable, and can withstand various stresses and vibrations generated during the nuclear fuel conversion process.

[0059] This stable connection method can ensure that the material can smoothly enter the reactor barrel 1 from the inclined feed part 20, avoid material leakage or transportation interruption caused by loose or unstable connection, and improve the reliability and safety of the device.

[0060] Secondly, the design of the external feed pipe 10 makes it easier to connect the inclined feed part 20 to the reactor barrel 1. During the installation process, it is only necessary to insert the bottom end of the inclined feed part 20 into the external feed pipe 10 and then fix it through the first flange assembly 3. This installation method is simple and fast, reducing installation time and workload. And when maintenance or overhaul is required, it is only necessary to loosen the bolts and nuts on the first flange assembly 3 to remove the inclined feed part 20 from the external feed pipe 10 and perform corresponding maintenance or overhaul work, thereby improving the maintainability of the equipment.

[0061] Furthermore, a pressure sensor for monitoring material pressure and a temperature sensor for monitoring material temperature may be provided in the feed sleeve 40. Both the pressure sensor and the temperature sensor are electrically connected to the controller of the screw feed device to achieve real-time monitoring.

[0062] In this embodiment, two pressure sensors are provided, which are respectively provided at the inner walls of both ends of the feed sleeve 40, so as to monitor the initial state of the material when it enters the sleeve and the state when it leaves the sleeve, and to fully understand the pressure change of the material during the conveying process, providing an important basis for judging the fluidity and blockage of the material; at the same time, the pressure sensor can timely detect the blockage or overload that may occur during the conveying process of the material. When the pressure exceeds the set value, the controller can take corresponding measures, such as stopping the feeding, clearing the blockage, etc., to protect the equipment and ensure the smooth progress of production.

[0063] A temperature sensor is provided, which is arranged at the inner wall of the middle part of the feed sleeve 40; the temperature sensor can timely detect the abnormal increase of the material temperature and provide an early warning signal for preventing fire and explosion. The controller can take corresponding measures according to the temperature signal, such as stopping the feeding, starting the cooling system, etc., to ensure production safety.

[0064] A pressure sensor and a temperature sensor are installed in the feed sleeve 40 and electrically connected to the controller of the screw feed device for real-time monitoring, which can realize comprehensive monitoring of the material conveying process, improve the safety, stability and efficiency of the production process, and also help optimize the production process and reduce production costs.

[0065] Furthermore, at least one annular sealing groove 8 is opened on the end face of a flange in the first flange assembly 3 , and an annular protrusion 9 matching the annular sealing groove 8 is formed on the end face of another flange in the first flange assembly 3 , and the annular protrusion 9 is placed in the annular sealing groove 8 .

[0066] Similarly, at least one annular sealing groove 8 can be opened on the end face of the first flange 53 or the second flange 401, and an annular protrusion 9 matching the annular sealing groove 8 is formed on the end face of the second flange 401 or the first flange 53, and the annular protrusion 9 is placed in the annular sealing groove 8.

[0067] The cooperation between the annular protrusion 9 and the annular sealing groove 8 can form a multiple sealing structure, which effectively prevents fluid leakage at the flange connection. Whether it is gas, liquid or other media, it can be better sealed in the system, improving the reliability and safety of the system. At the same time, in the pipeline system, the pressure may fluctuate. This design can better adapt to pressure changes. The annular protrusion 9 can be adjusted to a certain extent in the annular sealing groove 8 as the pressure changes, maintaining a good sealing effect.

[0068] The cooperation between the annular protrusion 9 and the annular sealing groove 8 can increase the contact area between the flanges, thereby improving the strength and stability of the connection. When subjected to external force or vibration, the flange connection is not easy to loosen or deform, and can also effectively prevent the flange from being misaligned during installation and use.

[0069] It should be noted that a sealing ring can also be arranged in the annular sealing groove 8, and the sealing ring can further fill the small gap that may exist between the annular protrusion 9 and the sealing groove, greatly improving the reliability of the seal and effectively preventing the leakage of various fluid media. At the same time, the sealing ring plays a buffering role between the flanges. When the system is subjected to thermal expansion and contraction caused by vibration, impact or temperature changes, the sealing ring can absorb part of the energy and reduce the impact on the flange connection, thereby enhancing the stability of the connection and reducing the risk of damage to the connection part due to external forces.

[0070] The sealing ring adopts a special structural design and contains shape memory material. The shape memory material can automatically adjust its shape according to changes in environmental factors such as temperature and pressure, thereby dynamically compensating the sealing gap. When the temperature changes during the operation of the system, causing the flange connection to expand and contract, or the pressure fluctuates, the shape memory sealing ring can automatically change its shape to adapt to the changes and always maintain a good sealing effect. At the same time, the shape memory material has good elastic recovery ability and can fit tightly to the surface of the flange. Even if there are slight unevenness or scratches on the surface of the flange, it can ensure that there is no gap between the sealing ring and the flange, thereby improving the reliability of the seal. In addition, the shape memory sealing ring will generate a certain amount of pressure in the process of restoring its shape. This pressure can enhance the fastening force of the flange connection and make the connection between the flanges more secure.

[0071] Based on the above-mentioned spiral feeding device capable of absorbing thermal displacement, the present invention further provides a nuclear fuel conversion system, including the above-mentioned spiral feeding device capable of absorbing thermal displacement. The nuclear fuel conversion system includes all technical solutions of the above-mentioned spiral feeding device capable of absorbing thermal displacement, and at least has all the advantages of the above-mentioned spiral feeding device capable of absorbing thermal displacement, which will not be described in detail here.

[0072] The present invention is further described above with the aid of specific embodiments. However, it should be understood that the specific description here should not be construed as limiting the essence and scope of the present invention. Various modifications made to the above embodiments by ordinary technicians in the field after reading this specification are all within the scope of protection of the present invention.

Claims

1. A spiral feeding device capable of absorbing thermal displacement, installed at the inlet of the reactor cylinder, characterized in that: include: A blowing mechanism, the blowing mechanism comprising an inclined feeding portion and a horizontal feeding portion arranged on one side of the top of the inclined feeding portion, wherein the bottom end of the inclined feeding portion is fixedly connected to the inlet of the reactor cylinder through a first flange assembly; A spiral feeding mechanism, the spiral feeding mechanism is arranged on a side of the horizontal feeding portion away from the inclined feeding portion, and is connected to the horizontal feeding portion through a bellows connecting mechanism; Wherein, the bellows connection mechanism comprises a bellows and a straight pipe; the straight pipe comprises a left straight pipe and a right straight pipe, the left straight pipe and the right straight pipe are respectively arranged at the left and right ends of the bellows; and a first flange is arranged at the outer ends of the left straight pipe and the right straight pipe; The spiral feeding mechanism includes a feeding sleeve and a spiral rotating shaft; the feeding sleeve is inserted and installed to the horizontal feeding part of the blowing mechanism along the corrugated pipe connecting mechanism, and a second flange is arranged on the outer wall of the feeding sleeve, and the second flange is connected to the first flange at the outer end of the right straight pipe; the spiral rotating shaft is inserted and installed in the feeding sleeve.

2. The spiral feeding device capable of absorbing thermal displacement according to claim 1, characterized in that: A nitrogen blowing feeding mechanism is fixedly installed on the top of the inclined feeding part.

3. The spiral feeding device capable of absorbing thermal displacement according to claim 1, characterized in that: The nitrogen blowing feeding mechanism comprises: An end cover, the end cover is mounted on the top of the inclined feeding part; A nitrogen blowing pipe extends from the end cover into the inclined feed portion.

4. The spiral feeding device capable of absorbing thermal displacement according to claim 3 is characterized in that: Two nitrogen blowing pipes are provided, one extending to the bottom end close to the inclined feed portion, and the other extending to the outlet close to the horizontal feed portion.

5. The spiral feeding device capable of absorbing thermal displacement according to claim 1, characterized in that: An external feed pipe is fixedly installed at the inlet of the reactor cylinder, the external feed pipe is sleeved on the outer wall of the bottom end of the inclined feed part, and the top end of the external feed pipe is fixedly connected to the inclined feed part through a first flange assembly.

6. The spiral feeding device capable of absorbing thermal displacement according to claim 5, characterized in that: The reactor barrel is connected to the bottom end of the external feed pipe by welding.

7. The spiral feeding device capable of absorbing thermal displacement according to claim 1, characterized in that: The bottom end of the inclined feeding pipe is in an oblique cone shape.

8. The spiral feeding device capable of absorbing thermal displacement according to claim 1, characterized in that: A pressure sensor and a temperature sensor are installed in the feed sleeve.

9. The spiral feeding device capable of absorbing thermal displacement according to claim 1, characterized in that: At least one annular sealing groove is provided on an end surface of one flange in the first flange assembly, and an annular protrusion matching the annular sealing groove is formed on an end surface of another flange in the first flange assembly, and the annular protrusion is placed in the annular sealing groove; And / or, at least one annular sealing groove is opened on the end surface of the first flange or the second flange, and an annular protrusion matching the annular sealing groove is formed on the end surface of the second flange or the first flange, and the annular protrusion is placed in the annular sealing groove.

10. A nuclear fuel conversion system, characterized in that: A screw feeding device capable of absorbing thermal displacement comprising the above-mentioned one of claims 1 to 9.

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