Guide plate and reactor top structure

Abstract

The invention belongs to the technical field of pressurized water reactors, and particularly relates to a guide plate and a reactor top structure. The reactor top structure comprises a pressure vessel top cover, a ventilation structure, a cylindrical shroud assembly, an anti-seismic bearing plate and a guide plate, the shroud assembly is fixedly installed at the upper end of the pressure vessel top cover, the ventilation structure is arranged on the outer wall of the shroud assembly, and the guide plate is installed on a reactor control rod driving mechanism in the shroud assembly. A flange is arranged at the top of the shroud assembly and used for installing an anti-seismic bearing plate, the anti-seismic bearing plate is in a flange plate shape, and the anti-seismic bearing plate is connected with the flange arranged at the top of the shroud assembly through bolts and fixed to the upper portion of the shroud assembly. The problems that in forced convection cooling of an existing pressurized water reactor top, power must be provided, noise can be generated, economical efficiency is poor, nuclear power safety is affected, installation is not easy, supporting performance is poor, and heat dissipation is not facilitated can be solved.

Description

Technical Field

[0001] The invention belongs to the technical field of pressurized water reactors, and in particular relates to a guide plate and a reactor top structure. Background Art

[0002] High temperature will cause the cable to overheat, which will affect the data transmission of the cable. The function of the guide plate is to prevent the high-temperature gas from flowing out from the top of the pile, and to make the high-temperature gas flow out from the ventilation structure on the upper part of the enclosure as much as possible, thereby reducing the outflow of the top high-temperature gas, thereby reducing the hot spot temperature at the top of the pile, and preventing the cables at the top of the pile from being baked by continuous high-temperature airflow, thereby preventing the top cables from overheating.

[0003] In the reactor top, the reactor control rod drive mechanism is cooled by natural convection to prevent the reactor control rod drive mechanism from overheating. At present, forced convection is used to cool the reactor control rod drive mechanism both at home and abroad. First of all, this method consumes a lot of electricity, which causes the cost of nuclear power plants to rise and the economy to decline. Secondly, the use of forced convection will inevitably use a lot of fans, which will generate huge noise and affect the accuracy of some detectors. Furthermore, after the nuclear power plant loses all power, the fans will stop, and the reactor control rod drive mechanism will not get the necessary cooling, which will cause the reactor control rod drive mechanism to overheat, and the performance of the overheated reactor control rod drive mechanism will decline.

[0004] In the prior art, a truss-type integrated top structure suitable for a high-temperature resistant drive mechanism adopts a bracket-type shroud for better heat dissipation. Although this shroud structure has good heat dissipation for the top, the shroud has disadvantages such as being difficult to install and having poor support. In addition, the integrated top of a pressurized water reactor and the shielding plate in the top adopt a shroud with strong sealing properties. However, this shroud has too strong sealing properties for the reactor control rod drive mechanism, resulting in the heat of the control rod drive mechanism in the shroud not being effectively discharged. The high-temperature gas generated after cooling the control rod drive mechanism will also continuously bake cables and other equipment. Therefore, the above two patents have obvious disadvantages. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a guide plate and a top structure that can solve the problems existing in the forced convection cooling of the top of the existing pressurized water reactor, such as the need to provide electricity, noise, poor economy, impact on nuclear power safety, difficulty in installation, poor support and poor heat dissipation.

[0006] The technical solution adopted by the present invention is:

[0007] A guide plate comprises a first mounting plate, a second mounting plate, a third mounting plate, a fourth mounting plate, a fifth mounting plate and a sixth mounting plate, wherein the six types of plates are arranged in layers from top to bottom, wherein the second mounting plate, the third mounting plate, the fourth mounting plate and the sixth mounting plate are located on the top layer, and the sixth mounting plate is a square structure; the first mounting plate is located on the second layer, and the first mounting plate is a fan-shaped structure located at four corners; the first mounting plate comprises several layers below, and each layer is provided with a fifth mounting plate; the guide plate after arrangement is a circular structure when viewed from above, and is in a structural form in which the outer side is high and the center is low.

[0008] One end of the second mounting plate, the third mounting plate and the fourth mounting plate matches the inner shape of the surrounding tube.

[0009] The No. 1 mounting plate, the No. 2 mounting plate, the No. 3 mounting plate, the No. 4 mounting plate, the No. 5 mounting plate, and the No. 6 mounting plate are all provided with through holes at the center of the space, the positions of the through holes correspond to the control rod drive mechanisms of each reactor, and the diameters of the through holes are the same as the outer diameters of the reactor control rod drive mechanisms.

[0010] A gap is left between adjacent mounting plates to compensate for thermal expansion.

[0011] The distance between the upper surface of the No. 6 mounting plate of the guide plate and the upper surface of the surrounding tube is 510mm; the No. 5 mounting plate and the No. 1 mounting plate are parallel and the distance between their upper surfaces and the upper surface of the surrounding tube is 498mm. The upper surface of the outer circle plate of the guide plate is 12mm higher than the upper surface of the adjacent inner circle plate. The upper surface height decreases by 12mm from the outside to the inside, and is lowest in the center. The distance between the upper surface of the No. 5 mounting plate in the center and the upper surface of the surrounding tube is 570mm.

[0012] A reactor top structure comprises a pressure vessel top cover, a ventilation structure, a cylindrical shroud assembly, a seismic support plate and a guide plate as claimed in claim 5, wherein the shroud assembly is fixedly mounted on the upper end of the pressure vessel top cover, a ventilation structure is provided on the outer wall of the shroud assembly, the guide plate is mounted on a reactor control rod drive mechanism inside the shroud assembly, a flange is provided on the top of the shroud assembly for mounting the seismic support plate, the seismic support plate is in the shape of a flange, and the seismic support plate is connected to the flange provided on the top of the shroud assembly by bolts and fixed above the shroud assembly.

[0013] The ventilation structure is divided into two parts, the upper and lower parts. Cooling air is sent into the interior of the shroud assembly from the lower ventilation structure. The cooling air is used to cool the control rod drive mechanism. The high-temperature gas generated after heating is discharged from the upper ventilation structure.

[0014] The outer diameter of the guide plate is smaller than the inner diameter of the shroud, and the through hole is sleeved on the reactor control rod driving mechanism.

[0015] The guide plate is located slightly above the middle of the upper ventilation structure, a supporting angle steel structure is arranged on the inner side of the upper ventilation structure, and the guide plate is installed on the supporting angle steel.

[0016] It also includes an anti-seismic plate and a shielding plate, wherein the anti-seismic plate is located above the guide plate, and the shielding plate is located above the anti-seismic plate, and the shielding plate serves as a cover plate for the inner hole of the anti-seismic support plate; it also includes a cable bracket fixed directly above the anti-seismic support plate, wherein the end of the cable bracket connected to the anti-seismic support plate is located on the outside of the shielding plate, and is located directly above the anti-seismic support plate.

[0017] Compared with the prior art, the embodiments of the present invention have the following beneficial effects:

[0018] (1) The guide plate and reactor top structure provided by the present invention use natural convection to cool the reactor control rod drive mechanism, which has good economy, quietness and safety. The installation of the guide plate can better utilize the heat dissipation function of the shroud air outlet and significantly reduce the temperature of the hot spot area on the reactor top.

[0019] (2) The present invention provides a guide plate and a reactor top structure, which adopts a structural setting in which the guide plate is fixed on the reactor control rod drive mechanism. When the high-temperature gas flows upward, the above guide plate can not only prevent the high-temperature gas from flowing upward, but also guide the blocked high-temperature gas to the air outlet of the shroud.

[0020] (3) The guide plate provided by the present invention has the advantages of simple structure and easy processing, manufacturing and installation.

[0021] (4) The guide plate and stack top structure provided by the present invention have both good support and excellent heat dissipation performance, which well meet the needs of reducing cable hot spots while ensuring the integration of the stack top structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0023] Figure 1 A front view of a guide plate provided by the present invention;

[0024] Figure 2 A schematic diagram of the overall structure of a guide plate provided by the present invention;

[0025] Figure 3A schematic diagram of the overall structure of a stack top structure capable of achieving natural convection cooling provided by the present invention;

[0026] Figure 4 A schematic diagram of a local structure of a stack top structure capable of achieving natural convection cooling provided by the present invention;

[0027] In the figure: 1. pressure vessel top cover, 2. ventilation structure, 3. enclosure, 4. seismic support plate, 5. cable bracket, 6. reactor control rod drive mechanism, 7. guide plate, 8. shielding plate, 9. seismic plate, 10. No. 1 mounting small plate, 11. No. 2 mounting small plate, 12. No. 3 mounting small plate, 13. No. 4 mounting small plate, 14. No. 5 mounting small plate, 15. No. 6 mounting small plate, 16. through hole. DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of 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 are within the scope of protection of the present invention.

[0029] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0030] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0031] like Figure 1 and Figure 2As shown, a guide plate provided by the present invention comprises a first installation plate 10, a second installation plate 11, a third installation plate 12, a fourth installation plate 13, a fifth installation plate 14, and a sixth installation plate 15, and the six types of plates are arranged in layers from top to bottom, wherein the second installation plate 11, the third installation plate 12, the fourth installation plate 13, and the sixth installation plate 15 are located on the top layer, one end of the second installation plate 11, the third installation plate 12, and the fourth installation plate 13 matches the internal shape of the surrounding tube, and the sixth installation plate 15 is a square structure; the first installation plate 10 is located on the second layer, and the first installation plate 10 is a fan-shaped structure, which is located at the four corners; the first installation plate 10 includes several layers below, and each layer is provided with a fifth installation plate 14;

[0032] The first mounting plate 10, the second mounting plate 11, the third mounting plate 12, the fourth mounting plate 13, the fifth mounting plate 14, and the sixth mounting plate 15 are all provided with a through hole 16 at the center of the space, the position of the through hole 16 corresponds to each reactor control rod drive mechanism 6, and the diameter of the through hole 16 is the same as the outer diameter of the reactor control rod drive mechanism 6;

[0033] The arranged guide plate is a circular structure when viewed from above, and has a high outer side and a low center. When the high-temperature gas flows upward, the guide plate can not only prevent the high-temperature gas from flowing upward, but also guide the blocked high-temperature gas to the air outlet of the surrounding tube.

[0034] The adjacent installation plates on the left and right of the guide plate have a certain gap to compensate for thermal expansion; the upper surface of the sixth installation plate 15 of the guide plate is 510mm away from the upper surface of the shroud 3. The fifth installation plate 14 and the first installation plate 10 are parallel and the upper surface of both is 498mm away from the upper surface of the shroud 3. The upper surface of the outer ring plate of the guide plate 7 is 12mm higher than the upper surface of the adjacent inner ring plate. The upper surface height decreases by 12mm from the outside to the inside, and is lowest at the center. The upper surface of the fifth installation plate 14 at the center is 570mm away from the upper surface of the shroud 3.

[0035] like Figure 3 and Figure 4As shown, a reactor top structure provided by the present invention comprises a pressure vessel top cover 1, a ventilation structure 2, a cylindrical shroud assembly 3, a seismic support plate 4, a cable bracket 5, a reactor control rod drive mechanism 6, a shielding plate 8, a seismic plate 9 and a guide plate 7. The shroud assembly 3 is fixedly mounted on the upper end of the pressure vessel top cover 1. To facilitate air cooling of the control rod drive mechanism 6, a ventilation structure 2 is provided on the outer wall of the shroud assembly 3. The ventilation structure 2 is divided into an upper and lower part. Cooling air is sent into the interior of the shroud assembly 3 from the lower ventilation structure 2. The cooling air is used to cool the control rod drive mechanism 6. The high-temperature gas generated after heating is discharged from the upper ventilation structure 2.

[0036] The guide plate 7 is installed inside the shroud assembly 3, and the outer diameter of the guide plate 7 is smaller than the inner diameter of the shroud 3. The guide plate 7 is mounted on the reactor control rod drive mechanism 6, and a plurality of through holes 16 are provided on the guide plate 7, which pass through the upper and lower ends of the guide plate. The through holes 16 are sleeved on the reactor control rod drive mechanism 6, and the through holes 16 are used to ensure the matching relationship between the reactor control rod drive mechanism 6 and the guide plate 7;

[0037] The guide plate 7 is located slightly above the middle of the upper ventilation structure 2, and a supporting angle steel structure is provided on the inner side of the upper ventilation structure 2, and the guide plate 7 is installed on the supporting angle steel, so that the guide plate 7 is installed on the inner side of the upper ventilation structure 2. The guide plate 7 can block the cooling wind below and facilitate the installation and replacement of a single control rod drive mechanism 6.

[0038] A flange is provided on the top of the enclosure assembly 3 for mounting an anti-seismic support plate 4 .

[0039] The anti-seismic support plate 4 is in the shape of a flange, and the anti-seismic support plate 4 is connected to a flange arranged on the top of the shroud assembly 3 through bolts and is fixed above the shroud assembly 3 .

[0040] It also includes an anti-seismic plate 9 and a shielding plate 8 . The anti-seismic plate 9 is located above the guide plate 7 , and the shielding plate 8 is located above the anti-seismic plate 9 . The shielding plate 8 serves as a cover plate for the inner hole of the anti-seismic support plate 4 .

[0041] In order to facilitate the centralized laying of cables and the connection between the cables and each control rod driving mechanism 6, it also includes a cable bracket 5 fixed directly above the seismic support plate 4. The end of the cable bracket 5 connected to the seismic support plate 4 is located on the outside of the shielding plate 8 and is located directly above the seismic support plate 4.

[0042] The guide plate 7 is made of carbon structural steel or stainless steel.

[0043] Six cable troughs are provided on the outside of the enclosure assembly 3. The temperature of the cables inside the cable troughs cannot exceed the specified temperature, so high-temperature gas cannot gather in the inner area of ​​the enclosure corresponding to the cable troughs. A gap will be left in the guide plate 7 here to avoid the gathering of high-temperature gas in the area inside the enclosure close to the cable troughs and reduce the hot spots in the cable troughs.

[0044] In the present invention, the top of the pile will adopt a natural convection cooling method. The specific process is that cold air enters the shroud 3 from the ventilation structure 2 at the bottom of the shroud 3. When the cold air enters passes through the surface of the reactor control rod drive mechanism 6, it takes away the heat on the reactor control rod drive mechanism 6 by convection heat exchange. The heated gas flows upward due to the density difference. The rising high-temperature gas will encounter the guide plate 7 at a certain height. After encountering the guide plate 7, the high-temperature gas will flow along the geometric shape of the guide plate 7. At this time, the high-temperature gas is being guided by the guide plate. The guided high-temperature gas will be discharged from the ventilation structure 2 at the top of the shroud 3. The shroud 3, ventilation structure 2, and guide plate 7 mentioned above are indispensable. For example, when the guide plate 7 is missing, a large amount of high-temperature airflow will flow out from the top of the pile, which will cause the cable at the top of the pile to overheat. Therefore, the guide plate 7 is used to guide most of the high-temperature airflow from the ventilation structure 2 at the top of the shroud 3 to ensure the normal use of the cable. In addition, cold air must also enter the shroud from the ventilation structure 2 at the bottom of the shroud 3, and only after being heated by the control rod drive mechanism 6 will a density difference be generated to drive the gas to flow upward, thereby realizing natural circulation. If cold air enters the shroud from the ventilation structure 2 at the top of the shroud 3, firstly, the control rod drive mechanism 6 will not be cooled as required, and secondly, the guide plate 7 will not play any role.

[0045] In traditional technology, the reactor control rod drive 6 mechanisms adopt forced convection. In this method, the inlet air flow rate is large, the residence time in the reactor top is short, and the gas temperature rise is small, so the outlet gas will not affect the use of the cable. However, its disadvantages are obvious, including high power consumption, poor economy, noise generation, and the need for electricity.

[0046] The present invention adopts a natural convection cooling method, which has the following significant advantages over the existing top cooling method. First, it adopts a natural convection cooling method, which does not require electricity, thereby reducing power consumption and increasing the economy of the nuclear power plant. Secondly, compared with the forced convection scheme, a large number of fans are required, and the fans generate a lot of noise that affects the accuracy of certain detectors. This scheme adopts natural convection cooling and has good quietness. Finally, when the nuclear power plant loses all power, the new top of the reactor in this scheme can still ensure that the reactor control rod drive mechanism 6 receives the necessary cooling to ensure the safe operation of the nuclear power plant.

[0047] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

[0048] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A guide plate, characterized in that: The invention comprises a first installation plate (10), a second installation plate (11), a third installation plate (12), a fourth installation plate (13), a fifth installation plate (14), and a sixth installation plate (15), wherein the six types of plates are arranged in layers from top to bottom, wherein the second installation plate (11), the third installation plate (12), the fourth installation plate (13), and the sixth installation plate (15) are located on the top layer, and the sixth installation plate (15) is a square structure; the first installation plate (10) is located on the second layer, and the first installation plate (10) is a fan-shaped structure located at four corners; the first installation plate (10) comprises a plurality of layers below, and each layer is provided with a fifth installation plate (14); the deflector after arrangement is a circular structure when viewed from above, and is in a structural form in which the outer side is high and the center is low.

2. The guide plate according to claim 1, characterized in that: One end of the second mounting plate (11), the third mounting plate (12) and the fourth mounting plate (13) matches the internal shape of the surrounding tube.

3. The guide plate according to claim 2, characterized in that: The first mounting plate (10), the second mounting plate (11), the third mounting plate (12), the fourth mounting plate (13), the fifth mounting plate (14), and the sixth mounting plate (15) are all provided with through holes (16) at the center of the space, the positions of the through holes (16) correspond to the control rod drive mechanisms (6) of each reactor, and the diameters of the through holes (16) are the same as the outer diameters of the control rod drive mechanisms (6) of the reactors.

4. The guide plate according to claim 3, characterized in that: A gap is left between adjacent mounting plates to compensate for thermal expansion.

5. The guide plate according to claim 4, characterized in that: The distance between the upper surface of the sixth mounting plate (15) of the guide plate and the upper surface of the shroud is 510 mm; the fifth mounting plate (14) and the first mounting plate (10) are parallel and the distance between the upper surface of the two and the upper surface of the shroud is 498 mm; the upper surface of the outer ring plate of the guide plate (7) is 12 mm higher than the upper surface of the adjacent inner ring plate, and the height of the upper surface decreases by 12 mm from the outside to the inside, and is the lowest at the center. The distance between the upper surface of the fifth mounting plate (14) at the center and the upper surface of the shroud is 570 mm.

6. A stack top structure, characterized in that: The invention comprises a pressure vessel top cover (1), a ventilation structure (2), a cylindrical shroud assembly (3), a seismic support plate (4) and a guide plate (7) as claimed in claim 5, wherein the shroud assembly (3) is fixedly mounted on the upper end of the pressure vessel top cover (1), a ventilation structure (2) is provided on the outer wall of the shroud assembly (3), the guide plate (7) is mounted on the reactor control rod drive mechanism (6) inside the shroud assembly (3), a flange is arranged on the top of the shroud assembly (3) for mounting the seismic support plate (4), the seismic support plate (4) is in the shape of a flange, the seismic support plate (4) is connected to the flange arranged on the top of the shroud assembly (3) by bolts, and is fixed on the top of the shroud assembly (3).

7. The stack top structure according to claim 6, characterized in that: The ventilation structure (2) is divided into two parts, an upper part and an lower part. Cooling air is sent from the lower ventilation structure (2) into the interior of the shroud assembly (3). The cooling air is used to cool the control rod drive mechanism (6). The high-temperature gas generated after heating is discharged from the upper ventilation structure (2).

8. The stack top structure according to claim 6, characterized in that: The outer diameter of the guide plate (7) is smaller than the inner diameter of the shroud (3), and the through hole (16) is sleeved on the reactor control rod driving mechanism (6).

9. The stack top structure according to claim 7, characterized in that: The guide plate (7) is located slightly above the middle of the upper ventilation structure (2), and a supporting angle steel structure is arranged on the inner side of the upper ventilation structure (2), and the guide plate (7) is installed on the supporting angle steel.

10. The stack top structure according to claim 6, characterized in that: It also includes an anti-seismic plate (9) and a shielding plate (8), wherein the anti-seismic plate (9) is located above the guide plate (7), and the shielding plate (8) is located above the anti-seismic plate (9), and the shielding plate (8) serves as a cover plate for the inner hole of the anti-seismic support plate (4); it also includes a cable bracket (5) fixed directly above the anti-seismic support plate (4), and the end of the cable bracket (5) connected to the anti-seismic support plate (4) is located on the outside of the shielding plate (8), and is located directly above the anti-seismic support plate (4).

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