Supercritical reactor

Abstract

The invention provides a supercritical reactor, which comprises a pressure vessel cylinder, a reactor internal is arranged in the pressure vessel cylinder, and the reactor internal accommodates a peripheral fuel assembly and a middle fuel assembly; an inlet connecting pipe and an outlet connecting pipe are arranged on the pressure container barrel, a lower cavity is formed in the bottom of the pressure container barrel, and one ends of the peripheral fuel assembly and the middle fuel assembly extend to the lower cavity or are arranged above the lower cavity; coolant introduced by the inlet connecting pipe flows to the lower cavity through the peripheral fuel assembly and returns to the middle fuel assembly so as to be discharged from the outlet connecting pipe. The peripheral fuel assembly and the middle fuel assembly are arranged, a coolant entering through the inlet connecting pipe is heated downwards through the peripheral fuel assembly and then enters the middle fuel assembly to be heated, the two-flow reactor core design is adopted, fast reactor core and thermal spectrum series connection are achieved, the height of the reactor core and the density change of the coolant can be reduced, and the reactor core is more compact. The reactor core height neutron distribution is more uniform, the temperature level of a fuel cladding is reduced, and the fuel circulation characteristic is improved.

Description

Technical Field

[0001] The invention relates to the technical field of reactor design, and in particular to a supercritical reactor. Background Art

[0002] Nuclear energy is an efficient and clean energy that can be developed on a large scale. At present, the nuclear power plants in service mainly use the second-generation and second-generation improved pressurized water reactor technology. As the third-generation nuclear power plants enter the mass construction period, the research work on the fourth-generation advanced nuclear energy technology that pursues higher safety, economy and less waste emissions has gradually become a research and development hotspot.

[0003] Traditional supercritical water reactors use a direct-flow reactor, in which the feed water flow rate is matched with the core flow rate to simplify the internal structure of the pressure vessel and limit the maximum temperature of the pressure vessel. The supercritical pressure coolant is heated, evaporated and superheated during a single pass through the core. The coolant density varies greatly throughout the core height, and the neutron distribution uniformity varies greatly throughout the core height.

[0004] In addition, a known disadvantage of the direct-flow reactor is that it is extremely sensitive to uneven heating of the coolant, which can cause the coolant and fuel cladding to overheat to temperatures of about 1000 degrees Celsius. At such high temperatures, the fuel cladding needs to use heat-resistant alloys, and the characteristics of the fuel cycle are prone to deteriorate sharply.

[0005] Based on this, the inventor of the present application proposes a supercritical reactor in order to solve the above technical problems. Summary of the invention

[0006] The technical problem to be solved by the present invention is to provide a supercritical reactor in order to overcome the defects of the prior art such as uneven heating of coolant resulting in low heat transfer efficiency.

[0007] The present invention solves the above technical problems through the following technical solutions:

[0008] The present invention provides a supercritical reactor, which is characterized by comprising:

[0009] A pressure vessel cylinder having a stack internal component disposed therein, wherein the stack internal component accommodates a peripheral fuel assembly and a middle fuel assembly;

[0010] The pressure vessel cylinder is provided with an inlet pipe and an outlet pipe and has a lower chamber at the bottom, and one end of the peripheral fuel assembly and the middle fuel assembly extends to the lower chamber or is placed above the lower chamber;

[0011] The coolant introduced by the inlet nozzle flows to the lower chamber through the peripheral fuel assembly and returns to the middle fuel assembly to be discharged from the outlet nozzle.

[0012] According to one embodiment of the present invention, the internal component comprises an isolation ring and a hanging basket cylinder, the middle fuel assembly is located in the isolation ring, and the isolation ring is located in the hanging basket cylinder to separate the peripheral fuel assembly and the middle fuel assembly;

[0013] The inlet pipe is communicated with the hanging basket cylinder, and the outlet pipe is communicated with the inner side of the isolation ring.

[0014] According to one embodiment of the present invention, at least one flow hole is opened on the cylinder of the hanging basket, and the coolant introduced by the inlet pipe enters the cylinder of the hanging basket through the flow hole.

[0015] According to one embodiment of the present invention, an inner cylinder is sleeved in the hanging basket cylinder, and the outer wall surface of the inner cylinder abuts against the inner wall surface of the hanging basket cylinder;

[0016] The inner cylinder and the isolation ring enclose an inlet cold chamber, the inner cylinder is provided with a matching hole which is in communication with the flow hole and has a corresponding position, and the isolation ring passes through the inner cylinder or is placed in the inner cylinder;

[0017] One end of the peripheral fuel assembly passes through the inner cylinder and extends into the inlet cold chamber or is placed under the inner cylinder, one end of the middle fuel assembly passes through the inner cylinder or is placed under the inner cylinder, and the interior of the isolation ring cooperates with the bottom of the inner cylinder to form a storage chamber.

[0018] According to one embodiment of the present invention, a first connecting hole is provided at one end of the peripheral fuel assembly extending to the inlet cold chamber, and the coolant introduced into the inlet cold chamber by the inlet pipe enters the peripheral fuel assembly through the first connecting hole and flows into the lower chamber;

[0019] A second connecting hole is formed at one end of the middle fuel assembly extending into the storage chamber, and the heated coolant is discharged to the outlet pipe through the second connecting hole.

[0020] According to one embodiment of the present invention, the peripheral fuel assembly and the middle fuel assembly are hollow; or, the peripheral fuel assembly and the middle fuel assembly are provided with flow channels for coolant to flow.

[0021] According to one embodiment of the present invention, the number of the flow holes is multiple;

[0022] The hanging basket cylinder is provided with a plurality of rows of flow units at intervals along its circumference, and each of the flow units is provided with at least one flow hole along the axial direction of the pressure vessel.

[0023] According to one embodiment of the present invention, the hanging basket cylinder and the pressure vessel cylinder enclose a containing annular cavity, and one end of the inlet pipe is connected to the containing annular cavity;

[0024] The coolant introduced by the inlet pipe flows into the hanging basket cylinder through the accommodating annular cavity.

[0025] According to one embodiment of the present invention, a throttling ring is provided in the accommodating annular cavity, and the throttling ring is respectively connected to the hanging basket cylinder and the inner wall of the pressure vessel;

[0026] The throttling ring is provided with a gap flow channel, and at least part of the coolant introduced by the inlet pipe flows to the lower chamber through the gap flow channel.

[0027] According to one embodiment of the present invention, the hanging basket cylinder and the pressure vessel cylinder enclose a containing annular cavity;

[0028] One end of the inlet pipe extends to the hanging basket cylinder and is connected to the hanging basket cylinder. A connecting hole is provided on the hanging basket cylinder, and the connecting hole is communicated with the accommodating annular cavity.

[0029] According to one embodiment of the present invention, a partition plate is provided in the hanging basket cylinder, and the top of the isolation ring is connected to the partition plate;

[0030] The partition plate is provided with at least one through hole communicating with the outlet pipe.

[0031] According to one embodiment of the present invention, a mounting plate is provided on the top of the hanging basket cylinder, an outlet heat chamber is enclosed between the mounting plate and the partition plate, and the outlet pipe is connected to the outlet heat chamber.

[0032] According to one embodiment of the present invention, a pressure vessel top cover is further provided on the top of the pressure vessel cylinder, and a receiving cavity is enclosed between the mounting plate and the pressure vessel top cover;

[0033] A flow groove is provided on the mounting plate or the in-pile component, and at least part of the coolant introduced by the inlet pipe flows into the accommodating cavity through the flow groove.

[0034] According to one embodiment of the present invention, at least one water flow hole is opened in the middle of the mounting plate, and the water flow hole is used to install a guide tube or an in-pile measurement conduit.

[0035] According to one embodiment of the present invention, a guide tube is provided between the inlet connecting pipe and the peripheral fuel assembly, one end of the guide tube faces the inlet end of the peripheral fuel assembly, and the coolant introduced into the inlet connecting pipe is led to the peripheral fuel assembly through the guide tube.

[0036] According to one embodiment of the present invention, a core lower plate is provided at the bottom of the internal components, an isolation cavity is provided in the core lower plate, and the middle fuel assembly is communicated with the isolation cavity and the lower chamber respectively;

[0037] The coolant introduced from the peripheral fuel assembly to the lower chamber flows to the middle fuel assembly through the isolation cavity and the lower chamber respectively, so that the coolant with uniform flow rate is obtained at the inlet of the middle fuel assembly.

[0038] The positive and progressive effects of the present invention are:

[0039] The supercritical reactor of the present invention is provided with peripheral fuel assemblies and middle fuel assemblies. The coolant entering through the inlet pipe is heated downward through the peripheral fuel assemblies and then enters the middle fuel assembly for heating. The dual-flow core design is adopted to realize the core fast and thermal spectrum series connection, which can not only reduce the coolant density change at the core height and make the neutron distribution at the core height more uniform, but also help to reduce the temperature level of the fuel cladding and improve the characteristics of the fuel cycle. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The above and other features, properties and advantages of the present invention will become more apparent through the following description in conjunction with the accompanying drawings and embodiments, in which:

[0041] Figure 1 A schematic diagram of the internal structure of a supercritical reactor according to an embodiment of the present invention;

[0042] Figure 2 for Figure 1 A schematic cross-sectional view of the inlet connection port;

[0043] Figure 3 It is a schematic diagram of the internal structure of another embodiment of the supercritical reactor of the present invention;

[0044] Figure 4 for Figure 3 A schematic cross-sectional view of the inlet connection port;

[0045] Figure 5 This is a schematic diagram of the internal structure of another embodiment of the supercritical reactor of the present invention;

[0046] Figure 6 for Figure 5 Schematic diagram of the cross section at the inlet pipe.

[0047] 1. Pressure vessel cylinder; 11. Inlet pipe; 12. Outlet pipe; 13. Lower chamber; 14. Accommodating ring cavity; 15. Throttle ring; 151. Gap flow channel; 16. Guide pipe;

[0048] 2. Internal components; 21. Circulation slot; 22. Lower core plate; 23. Isolation cavity;

[0049] 3. peripheral fuel assembly; 31. first communication hole;

[0050] 4. middle fuel assembly; 41. second communication hole;

[0051] 5. Isolation ring; 51. Storage chamber;

[0052] 6. Basket cylinder; 61. Circulation hole; 611. Circulation unit; 62. Inner cylinder; 63. Inlet cold chamber; 64. Matching hole; 65. Connection hole; 66. Partition plate; 661. Through hole; 67. Mounting plate; 671. Water flow hole; 68. Outlet hot chamber;

[0053] 7. Top cover of pressure vessel; 71. Accommodating cavity. DETAILED DESCRIPTION

[0054] The present invention is further described below in conjunction with specific embodiments and drawings. More details are elaborated in the following description to facilitate a full understanding of the present invention. However, the present invention can obviously be implemented in a variety of other ways different from the description herein. Those skilled in the art can make similar generalizations and deductions based on actual application situations without violating the connotation of the present invention. Therefore, the protection scope of the present invention should not be limited by the content of this specific embodiment.

[0055] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0056] Please refer to Figures 1 to 6 The present invention proposes a supercritical reactor, which includes a pressure vessel cylinder 1, in which an internal component 2 is arranged, and the internal component 2 accommodates a peripheral fuel assembly 3 and a middle fuel assembly 4; an inlet pipe 11 and an outlet pipe 12 are arranged on the pressure vessel cylinder 1, and a lower chamber 13 is provided at the bottom or is placed above the lower chamber 13, and one end of the peripheral fuel assembly 3 and the middle fuel assembly 4 extends to the lower chamber 13; the coolant introduced into the inlet pipe 11 flows to the lower chamber 13 through the peripheral fuel assembly 3 and returns to the middle fuel assembly 4 to be discharged from the outlet pipe 12.

[0057] The present invention adopts a dual-flow core design of a peripheral fuel assembly 3 and a central fuel assembly 4. The coolant introduced through the inlet pipe 11 first flows through the peripheral fuel assembly 3 to the lower chamber 13, and then flows upward through the central fuel assembly 4 in the lower chamber 13. This is beneficial to reducing the coolant density variation at the core height, making the neutron distribution at the core height more uniform, and is also beneficial to reducing the temperature requirements of the cladding, thereby improving the characteristics of the fuel cycle.

[0058] The number and arrangement of the peripheral fuel assemblies 3 are not limited here, and the peripheral fuel assemblies 3 may be thermal neutron fuel assemblies. Similarly, the number and arrangement of the central fuel assemblies 4 are not limited here, and the central fuel assemblies 4 may be fast neutron fuel assemblies, thereby achieving reactor fuel proliferation.

[0059] Please continue to refer to Figure 1 and Figure 2 The internal component 2 includes an isolation ring 5 and a hanging basket cylinder 6, the middle fuel assembly 4 is located in the isolation ring 5, and the isolation ring 5 is located in the hanging basket cylinder 6 to separate the peripheral fuel assembly 3 and the middle fuel assembly 4; the inlet pipe 11 is connected to the hanging basket cylinder 6, and the outlet pipe 12 is connected to the inner side of the isolation ring 5.

[0060] The isolation ring 5 is located in the hanging basket cylinder 6, and is used to separate the peripheral fuel assembly 3 and the middle fuel assembly 4. The inlet pipe 11 is connected to the peripheral fuel assembly 3. The coolant initially entering through the inlet pipe 11 is first heated by the peripheral fuel assembly 3 and flows downward to the lower chamber 13, and then flows upward through the lower chamber 13 along the middle fuel assembly 4 for reflux heating, and finally flows out from the outlet pipe 12.

[0061] That is, dual-flow heating can be realized through the coordinated arrangement of the isolation ring 5 and the hanging basket cylinder 6, which reduces the coolant density variation at the core height and helps to make the neutron distribution at the core height more uniform.

[0062] Optionally, at least one flow hole 61 is opened on the hanging basket cylinder 6 , and the coolant introduced by the inlet pipe 11 enters the hanging basket cylinder 6 through the flow hole 61 .

[0063] The flow hole 61 is provided to introduce the coolant introduced by the inlet pipe 11 into the space between the hanging basket cylinder 6 and the isolation ring 5. The space between the hanging basket cylinder 6 and the isolation ring 5 can form a buffer for the incoming coolant, thereby improving the uniformity of the coolant flow entering the peripheral fuel assembly 3.

[0064] Please continue to refer to Figure 1 and Figure 2 , the inner cylinder 62 is sleeved in the hanging basket cylinder 6, and the inner cylinder 62 is stacked and sleeved on the inner side of the hanging basket cylinder 6. That is, the outer wall surface of the inner cylinder 62 is closely fitted with the inner wall surface of the hanging basket cylinder 6.

[0065] An inlet cold chamber 63 is enclosed between the inner cylinder 62 and the isolation ring 5. A matching hole 64 is provided on the inner cylinder 62, which is connected to the flow hole 61 and has a corresponding position. One end of the isolation ring 5 is connected to the lower plate 22 of the core (parameters are described below), and the other end of the isolation ring 5 passes through the inner cylinder 62 and the top is connected to the partition plate 66 (see below), or the isolation ring 5 is partially placed in the inner cylinder 62. For example, the isolation ring 5 is divided into two parts, one part is located in the inner cylinder 62, and the other part is installed below the inner cylinder 62.

[0066] One end of the peripheral fuel assembly 3 passes through the inner cylinder 62 and extends into the inlet cold chamber 63 or is placed under the inner cylinder 62. One end of the middle fuel assembly 4 passes through the inner cylinder 62 or is placed under the inner cylinder 62. The interior of the isolation ring 5 cooperates with the bottom of the inner cylinder 62 to form a storage chamber 51.

[0067] The inner cylinder 62 is provided for mounting the peripheral fuel assembly 3 and the middle fuel assembly 4, and providing support for the peripheral fuel assembly 3 and the middle fuel assembly 4. On the other hand, an inlet cold chamber 63 is formed between the outer side of the isolation ring 5 and the inner cylinder 62. The coolant introduced through the inlet connecting pipe 11 enters the inlet cold chamber 63 through the flow hole 61 and the matching hole 64, and forms a buffer in the inlet cold chamber 63, thereby improving the uniformity of the coolant flow entering the peripheral fuel assembly 3.

[0068] Furthermore, a first connecting hole 31 is formed at one end of the peripheral fuel assembly 3 extending to the inlet cold chamber 63, and the coolant introduced into the inlet cold chamber 63 by the inlet connecting pipe 11 enters the peripheral fuel assembly 3 through the first connecting hole 31 and flows to the lower chamber 13; a second connecting hole 41 is formed at one end of the middle fuel assembly 4 extending to the storage chamber 51, and the heated coolant is discharged to the outlet connecting pipe 12 through the second connecting hole 41.

[0069] It should be noted that in the present invention, both the first communicating hole 31 and the second communicating hole 41 are long strip holes, so as to increase the efficiency of coolant inflow or discharge. In practice, the number and shape of the first communicating hole 31 and the second communicating hole 41 are not limited. For example, the number of the first communicating hole 31 and the second communicating hole 41 can be one, two or more, respectively, and the shape of the first communicating hole 31 and the second communicating hole 41 can be, but not limited to, circular, square or polygonal, etc., which are not limited here.

[0070] Moreover, the sizes of the first communicating hole 31 and the second communicating hole 41 can also be adjusted according to actual needs, which is only an example.

[0071] The coolant flow process of this embodiment is as follows: the coolant received by the inlet cold chamber 63 flows into the peripheral fuel assembly 3 through the first connecting hole 31 for heating, and flows downward into the lower chamber 13, and then the coolant in the lower chamber 13 enters through the bottom of the middle fuel assembly 4, and is heated upwards and then discharged into the storage chamber 51 through the second connecting hole 41, and finally discharged through the outlet pipe 12.

[0072] In one embodiment, the peripheral fuel assembly 3 and the middle fuel assembly 4 are hollow. That is, the hollow chamber of the peripheral fuel assembly 3 is connected to the first connecting hole 31, and the hollow chamber of the middle fuel assembly 4 is connected to the second connecting hole 41, thereby allowing the coolant to flow.

[0073] In some optional other embodiments, the peripheral fuel assembly 3 and the middle fuel assembly 4 are provided with flow channels for coolant circulation.

[0074] For example, a dedicated circulation channel may be provided inside for the circulation of the coolant; or a circulation channel may be provided outside for the circulation of the coolant. The arrangement is merely an example and is not limiting.

[0075] Please continue to refer to Figure 1 For the circulation holes 61 on the hanging basket cylinder 6, the number of the circulation holes 61 can be multiple.

[0076] That is, the hanging basket cylinder 6 is provided with a plurality of rows of flow units 611 at intervals along its circumference, and each flow unit 611 is provided with at least one flow hole 61 along the axial direction of the pressure vessel.

[0077] Correspondingly, the number and location of the matching holes 64 provided on the inner cylinder 62 are consistent with those of the flow holes 61 , which will not be described in detail herein, so that the coolant can reach the inlet cold chamber 63 through the flow holes 61 and the matching holes 64 .

[0078] Furthermore, a containing annular cavity 14 is enclosed between the hanging basket cylinder 6 and the pressure vessel cylinder 1 , and one end of the inlet pipe 11 is connected to the containing annular cavity 14 ; the coolant introduced by the inlet pipe 11 flows into the hanging basket cylinder 6 through the containing annular cavity 14 .

[0079] That is, the coolant introduced through the inlet pipe 11 first enters the accommodating annular cavity 14, and then enters the inner cylinder 62 through the accommodating annular cavity 14. The accommodating annular cavity 14 can play a buffering role, so that the flow rate of the coolant entering the inner cylinder 62 is more uniform.

[0080] Furthermore, a throttling ring 15 is provided in the accommodating annular cavity 14, and the throttling ring 15 is respectively connected to the inner walls of the hanging basket cylinder 6 and the pressure vessel cylinder 1; a gap flow channel 151 is opened on the throttling ring 15, and at least part of the coolant introduced by the inlet pipe 11 flows to the lower chamber 13 through the gap flow channel 151.

[0081] On the one hand, the throttling ring 15 relatively blocks the accommodating ring cavity 14, so that most of the coolant flowing in through the inlet pipe 11 flows into the inner cylinder 62, meeting the flow requirement of heat exchange.

[0082] On the other hand, a gap flow channel 151 is provided on the throttling ring 15 for introducing a small amount of coolant to cool the inner wall of the pressure vessel cylinder 1, thereby reducing the design temperature of the pressure vessel cylinder 1 and helping to increase the core flow rate, thereby improving the cooling and heat transfer efficiency.

[0083] Specifically, the throttle ring 15 can be divided into two parts, for example, one part is installed on the hanging basket cylinder 6, and the other part is installed on the inner wall of the pressure vessel cylinder 1, and the two parts cooperate to form a gap flow channel 151. Alternatively, the throttle ring 15 can also be an integrated structure, for example, installed on the outside of the hanging basket cylinder 6, and form a gap flow channel 151 between the inner wall of the pressure vessel cylinder 1, both methods are acceptable and are not limited here.

[0084] In some optional other implementations, please refer to Figure 3 and Figure 4 The hanging basket cylinder 6 and the pressure vessel cylinder 1 enclose an accommodating annular cavity 14; one end of the inlet pipe 11 extends to the hanging basket cylinder 6 and is connected to the hanging basket cylinder 6. A connecting hole 65 is opened on the hanging basket cylinder 6, and the connecting hole 65 is connected to the accommodating annular cavity 14.

[0085] That is, refer to Figure 3 and Figure 4 The inlet pipe 11 can directly transport the coolant to the inner cylinder 62, and flow to the accommodating annular cavity 14 through the connecting hole 65 set on the inner cylinder 62, so that there is also coolant in the accommodating annular cavity 14. In this way, the accommodating annular cavity 14 can further cool the peripheral side wall of the pressure vessel through the gap flow channel 151.

[0086] Regarding the coolant circulation method, the above Figure 1 and Figure 2 How to set up and Figure 3 and Figure 4 Any setting method is available and is not limited here.

[0087] Please refer to Figure 1 and Figure 3 A partition plate 66 is provided in the hanging basket cylinder 6 , and the top of the isolation ring 5 is connected to the partition plate 66 ; at least one through hole 661 communicating with the outlet pipe 12 is opened on the partition plate 66 .

[0088] Furthermore, a mounting plate 67 is provided on the top of the hanging basket cylinder 6 , and an outlet hot chamber 68 is enclosed between the mounting plate 67 and the partition plate 66 , and the outlet pipe 12 is connected to the outlet hot chamber 68 .

[0089] That is, the partition plate 66 is used to converge the coolant discharged from the middle fuel assembly 4, so that the coolant flow rate in the outlet hot chamber 68 is more uniform.

[0090] It should be noted that the mounting plate 67 is sealed and connected to the inner cylinder 62 by welding, and other optional sealing installation methods may also be used, which are not limited here. The mounting plate 67 is used to isolate the outlet hot chamber 68 and the accommodating chamber 71 of the pressure vessel top cover 7.

[0091] Specifically, a pressure vessel top cover 7 is also provided on the top of the pressure vessel cylinder 1, and a accommodating cavity 71 is enclosed between the mounting plate 67 and the pressure vessel top cover 7; a flow groove 21 is opened on the mounting plate 67 or the in-core component 2, and at least part of the coolant introduced by the inlet pipe 11 flows into the accommodating cavity 71 through the flow groove 21.

[0092] A flow groove 21 is provided on the mounting plate 67 or the in-core component 2, and part of the coolant can be guided to the accommodating cavity 71 for storage through the flow groove 21. When a serious accident occurs in the core, the stored coolant can flow to the core through the guide tube and the fuel assembly due to pressure and its own gravity, so as to alleviate the occurrence of the core accident.

[0093] Reference Figure 1 The present invention takes the example of setting the flow groove 21 on the top of the internal component 2 as an example for explanation, and the number of the flow grooves 21 can be one, two, or more, etc., which is not limited here. When the number of the flow grooves 21 is more than one, the plurality of flow grooves 21 can be evenly spaced and arranged along the outer circumference of the internal component 2, thereby improving the uniformity of the coolant flowing to the accommodating cavity 71 and also improving the cooling efficiency of the pressure vessel top cover 7.

[0094] In some other embodiments, the circulation groove 21 can also be set on the mounting plate 67, and the outer periphery of the mounting plate 67 is connected to the pressure vessel cylinder 1 or the in-core component 2. The specific setting method of the circulation groove 21 is only given as an example and is not limited.

[0095] Optionally, at least one water flow hole 671 is opened in the middle of the mounting plate 67, and the water flow hole 671 is used to install a guide tube or an in-pile measurement guide tube.

[0096] The guide tube or the in-core measuring conduit is used to provide a channel for the coolant in the accommodating chamber 71 to flow downward, so that when a serious accident occurs in the core, the coolant in the accommodating chamber 71 can be used to replenish the core with water.

[0097] For example, one end of the guide tube is inserted into the water flow hole 671, and the other end is connected to the top of the peripheral fuel assembly 3 or the middle fuel assembly 4 through a flange, or the other end of the guide tube is inserted into the peripheral fuel assembly 3 or the middle fuel assembly 4 to be connected to the peripheral fuel assembly 3 or the middle fuel assembly 4. In this way, the cooling water in the accommodating cavity 71 can flow through the guide tube to the peripheral fuel assembly 3 or the middle fuel assembly 4 and finally flow to the core when a serious core accident occurs, thereby providing coolant for the core and slowing down the progress of the accident.

[0098] Please refer to Figure 5 and Figure 6 A guide tube 16 is provided between the inlet pipe 11 and the peripheral fuel assembly 3 , one end of the guide tube 16 faces the inlet end of the peripheral fuel assembly 3 , and the coolant introduced into the inlet pipe 11 is led to the peripheral fuel assembly 3 through the guide tube 16 .

[0099] Please refer to Figure 5 A guide tube 16 may be disposed inside each flow hole 61 , and the guide tube 16 may allow the coolant to flow directly to the inlet of the peripheral fuel assembly 3 , thereby improving the efficiency of the peripheral fuel assembly 3 in receiving the coolant.

[0100] Please continue to refer to Figure 1 A core lower plate 22 is provided at the bottom of the internal component 2, and an isolation cavity 23 is provided in the core lower plate 22. The middle fuel assembly 4 is connected with the isolation cavity 23 and the lower chamber 13 respectively; the coolant led to the lower chamber 13 by the peripheral fuel assembly 3 flows into the middle fuel assembly 4 through the isolation cavity 23 and the lower chamber 13 respectively, so that each of the middle fuel assemblies 4 has a more uniform flow rate.

[0101] An isolation cavity 23 is provided on the lower core plate 22, and a plurality of channels connected to the middle fuel assembly 4 are opened on the lower core plate 22. The coolant flowing to the lower chamber 13 through the peripheral fuel assembly 3 is mixed with the lower chamber 13 and enters the middle fuel assembly 4 through the isolation cavity 23, thereby making the inlet flow distribution of the middle fuel assembly 4 more uniform.

[0102] The operating principle of one embodiment of the supercritical reactor of the present invention is described as follows:

[0103] The coolant at 280°C enters the accommodating annular cavity 14 through the inlet pipe 11, flows into the basket cylinder 6 through the accommodating annular cavity 14, then enters the peripheral fuel assembly 3, and descends to the lower chamber 13 through the peripheral fuel assembly 3. At this time, the average mixing temperature of the coolant heated by the peripheral fuel assembly 3 is 385°C. In the lower chamber 13, the coolants heated unevenly are mixed with each other and distributed to the inlet area of ​​the middle fuel assembly 4, and then flow upward through the middle fuel assembly 4 to the outlet hot chamber 68. At this time, the temperature of the coolant in the outlet hot chamber 68 reaches 510°C. Thereafter, the overheated coolant is mixed in the outlet hot chamber 68 and finally discharged from the outlet pipe 12.

[0104] The above-mentioned 280° C., 385° C. and 510° C. are just examples and are not limited to specific numbers.

[0105] It can be seen that the heating temperature of the coolant of the middle fuel assembly 4 of the present invention is 125°C, which can ensure that the cladding temperature of the middle fuel assembly 4 is controlled within 700°C.

[0106] It should be noted that the coolant at 280°C partially flows into the accommodating cavity 71 and the area between the pressure vessel cylinder 1 and the in-core component 2, so that the temperature of the pressure vessel top cover 7 and the pressure vessel cylinder 1 can be controlled within 400°C, which will not exceed the temperature value that the existing pressure vessel top cover 7 and the pressure vessel cylinder 1 can withstand.

[0107] Similarly, 125° C. and 700° C. are just examples and are not limiting.

[0108] In summary, the supercritical reactor of the present invention is provided with a peripheral fuel assembly 3 and a middle fuel assembly 4. The coolant entering through the inlet pipe 11 is heated downward through the peripheral fuel assembly 3, and then enters the middle fuel assembly 4 for heating. The dual-flow core design is adopted to realize the core fast and thermal spectrum series connection, which can not only reduce the coolant density change at the core height, make the neutron distribution at the core height more uniform, but also help to reduce the temperature level of the fuel cladding and improve the characteristics of the fuel cycle.

[0109] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "install", "connect", "connect", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can also be a mechanical connection. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0110] In the description of the present application, it should be understood that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction, and therefore cannot be understood as limiting the scope of protection of the present application; the directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself.

[0111] The present application uses specific words to describe the embodiments of the present application. For example, "one embodiment", "an embodiment", and / or "some embodiments" refer to a certain feature, structure or characteristic related to at least one embodiment of the present application. Therefore, it should be emphasized and noted that "one embodiment" or "an embodiment" or "an alternative embodiment" mentioned twice or multiple times in different positions in this specification does not necessarily refer to the same embodiment. In addition, some features, structures or characteristics in one or more embodiments of the present application can be appropriately combined.

[0112] Accordingly, in some embodiments, the numerical parameters used in the specification and claims are approximate values, which may vary according to the characteristics required by the individual embodiments. In some embodiments, the numerical parameters should take into account the specified significant digits and adopt the method of general digit retention. Although the numerical domains and parameters used to confirm the breadth of the range in some embodiments of the present application are approximate values, in specific embodiments, the setting of such numerical values ​​is as accurate as possible within the feasible range.

[0113] Although the present invention is disclosed as above with preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications without departing from the spirit and scope of the present invention. Therefore, any modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the protection scope defined by the claims of the present invention.

Claims

1. A supercritical reactor, characterized in that: include: A pressure vessel cylinder having a stack internal component disposed therein, wherein the stack internal component accommodates a peripheral fuel assembly and a middle fuel assembly; The pressure vessel cylinder is provided with an inlet pipe and an outlet pipe and has a lower chamber at the bottom, and one end of the peripheral fuel assembly and the middle fuel assembly extends to the lower chamber or is placed above the lower chamber; The coolant introduced by the inlet nozzle flows to the lower chamber through the peripheral fuel assembly and returns to the middle fuel assembly to be discharged from the outlet nozzle.

2. The supercritical reactor according to claim 1, characterized in that: The internal components include an isolation ring and a hanging basket cylinder, the middle fuel assembly is located in the isolation ring, and the isolation ring is located in the hanging basket cylinder to separate the peripheral fuel assembly and the middle fuel assembly; The inlet pipe is communicated with the hanging basket cylinder, and the outlet pipe is communicated with the inner side of the isolation ring.

3. The supercritical reactor according to claim 2, characterized in that: At least one flow hole is provided on the cylinder of the hanging basket, and the coolant introduced by the inlet pipe enters the cylinder of the hanging basket through the flow hole.

4. The supercritical reactor according to claim 3, characterized in that: An inner cylinder is sleeved in the hanging basket cylinder, and the outer wall surface of the inner cylinder abuts against the inner wall surface of the hanging basket cylinder; The inner cylinder and the isolation ring enclose an inlet cold chamber, the inner cylinder is provided with a matching hole which is in communication with the flow hole and has a corresponding position, and the isolation ring passes through the inner cylinder or is placed in the inner cylinder; One end of the peripheral fuel assembly passes through the inner cylinder and extends into the inlet cold chamber or is placed under the inner cylinder, one end of the middle fuel assembly passes through the inner cylinder or is placed under the inner cylinder, and the interior of the isolation ring cooperates with the bottom of the inner cylinder to form a storage chamber.

5. The supercritical reactor according to claim 4, characterized in that: A first connecting hole is formed at one end of the peripheral fuel assembly extending to the inlet cold chamber, and the coolant introduced into the inlet cold chamber by the inlet pipe enters the peripheral fuel assembly through the first connecting hole and flows into the lower chamber; A second connecting hole is formed at one end of the middle fuel assembly extending into the storage chamber, and the heated coolant is discharged to the outlet pipe through the second connecting hole.

6. The supercritical reactor according to claim 5, characterized in that: The peripheral fuel assembly and the middle fuel assembly are hollow; or, the peripheral fuel assembly and the middle fuel assembly are provided with flow channels for coolant to flow.

7. The supercritical reactor according to claim 3, characterized in that: The number of the flow holes is multiple; The hanging basket cylinder is provided with a plurality of rows of flow units at intervals along its circumference, and each of the flow units is provided with at least one flow hole along the axial direction of the pressure vessel.

8. The supercritical reactor according to claim 3, characterized in that: The hanging basket cylinder and the pressure vessel cylinder enclose a containing annular cavity, and one end of the inlet pipe is connected to the containing annular cavity; The coolant introduced by the inlet pipe flows into the hanging basket cylinder through the accommodating annular cavity.

9. The supercritical reactor according to claim 8, characterized in that: A throttling ring is provided in the accommodating annular cavity, and the throttling ring is respectively connected to the hanging basket cylinder and the inner wall of the pressure vessel; The throttling ring is provided with a gap flow channel, and at least part of the coolant introduced by the inlet pipe flows to the lower chamber through the gap flow channel.

10. The supercritical reactor according to claim 3, characterized in that: The hanging basket cylinder and the pressure vessel cylinder enclose a containing annular cavity; One end of the inlet pipe extends to the hanging basket cylinder and is connected to the hanging basket cylinder. A connecting hole is provided on the hanging basket cylinder, and the connecting hole is communicated with the accommodating annular cavity.

11. The supercritical reactor according to claim 3, characterized in that: A partition plate is provided in the cylinder of the hanging basket, and the top of the isolation ring is connected to the partition plate; The partition plate is provided with at least one through hole communicating with the outlet pipe.

12. The supercritical reactor according to claim 11, characterized in that: A mounting plate is provided on the top of the hanging basket cylinder, and an outlet heat chamber is formed between the mounting plate and the partition plate, and the outlet pipe is communicated with the outlet heat chamber.

13. The supercritical reactor according to claim 12, characterized in that: A pressure vessel top cover is also provided on the top of the pressure vessel cylinder, and a receiving cavity is enclosed between the mounting plate and the pressure vessel top cover; The mounting plate or the in-pile component is provided with a flow groove, and at least part of the coolant introduced by the inlet pipe flows into the accommodating cavity through the flow groove.

14. The supercritical reactor according to claim 13, characterized in that: At least one water flow hole is opened in the middle of the installation plate, and the water flow hole is used for installing a guide cylinder or an in-pile measurement guide tube.

15. The supercritical reactor according to claim 3, characterized in that: A guide tube is provided between the inlet connecting pipe and the peripheral fuel assembly, one end of the guide tube faces the inlet end of the peripheral fuel assembly, and the coolant introduced by the inlet connecting pipe is led to the peripheral fuel assembly through the guide tube.

16. The supercritical reactor according to claim 1, characterized in that: A core lower plate is provided at the bottom of the internal components, and an isolation cavity is provided in the core lower plate, and the middle fuel assembly is communicated with the isolation cavity and the lower chamber respectively; The coolant introduced from the peripheral fuel assembly to the lower chamber flows uniformly to the middle fuel assembly through the isolation cavity and the lower chamber respectively.

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