Heterogeneous quasi-static reactor core loading system and method of pebble-bed high-temperature gas cooled reactor

Abstract

The invention provides a heterogeneous quasi-static reactor core loading system and method for a pebble-bed high-temperature gas cooled reactor, the system comprises a pebble-bed reactor and a conveying and ball distributing assembly, the reactor core of the pebble-bed reactor is provided with a filling area, the upper end of the pebble-bed reactor is provided with a ball inlet pipe, and the lower end of the pebble-bed reactor is provided with a ball discharging pipe; the ball feeding pipe and the ball discharging pipe are both communicated with the filling area, the filling area comprises a first filling area and a second filling area, the first filling area is located in the middle of the filling area, the second filling area surrounds the first filling area in the circumferential direction of the first filling area, the conveying and ball distributing assembly is provided with a ball inlet and a ball outlet, and the ball inlet is connected with the ball discharging pipe. The ball outlet is connected with the ball inlet pipe and used for receiving and separating the graphite balls and the fuel balls discharged by the ball discharging pipe, the separated graphite balls are introduced into the first filling area, and the fuel balls are introduced into the second filling area. According to the loading system, the center temperature of reactor fuel can be reduced, and the heat production power and safety of a reactor are improved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of nuclear engineering test, and particularly relates to a non-homogeneous quasi-static core loading system and method of a pebble bed high temperature gas cooled reactor. BACKGROUND

[0002] The pebble bed high temperature gas cooled reactor has good inherent safety, high power generation efficiency, strong environmental adaptability and wide application, and has broad commercial application prospects in the fields of nuclear power generation, cogeneration and high temperature process heat. The reactor adopts helium coolant, graphite moderator and coated particle fuel elements, and is stacked into a cylindrical cavity by graphite components, and a flowable spherical fuel element, i.e. a "pebble bed" active zone, is accumulated in the cavity. The spherical fuel elements are filled from above the core and move downward by gravity, and this filling method can realize continuous refueling of the reactor, which is beneficial to improve the utilization rate of rated power. In the balanced core state, if the reactor is entirely filled with random fuel balls, the pebble bed active zone can be considered as a homogeneous core, and if the pebble bed active zone is filled with partitioned graphite balls and fuel balls, it is a non-homogeneous core.

[0003] Due to the characteristics of the neutron physical field of the pebble bed core, the heat release of the reactor will be concentrated in the middle part of the cylindrical core, resulting in the appearance of the center hot spot, and the center hot spot will increase the center temperature of the fuel elements in the region. This parameter is an important safety limit in core design, and if the center temperature of the fuel is too high, the probability of failure of the coating layer and leakage of radioactive substances will be greatly increased. SUMMARY

[0004] The present application aims to at least partially solve one of the technical problems in the related art.

[0005] To this end, the embodiments of the present application propose a non-homogeneous quasi-static core loading system and method of a pebble bed high temperature gas cooled reactor, which can reduce the center temperature of the reactor fuel and improve the heat generation power and safety of the reactor.

[0006] The non-homogeneous quasi-static core loading system of a pebble bed high temperature gas cooled reactor according to the embodiments of the present application comprises:

[0007] The pebble bed reactor has a core with a filling area, an upper end of the pebble bed reactor is provided with a ball inlet pipe, and a lower end of the pebble bed reactor is provided with a ball discharge pipe, the ball inlet pipe and the ball discharge pipe are both in communication with the filling area, the filling area comprises a first filling area and a second filling area, the first filling area is located in the middle of the filling area, the second filling area surrounds the first filling area along the circumference of the first filling area, and in the height direction of the pebble bed reactor, the first filling area is arranged corresponding to the ball discharge pipe;

[0008] A ball conveying and separating assembly has an inlet and an outlet. The inlet is connected to the unloading pipe, and the outlet is connected to the inlet pipe, for receiving and separating graphite balls and fuel balls discharged from the unloading pipe, and for passing the separated graphite balls into the first filling area and the fuel balls into the second filling area.

[0009] The heterogeneous quasi-static core loading system of the pebble bed high-temperature gas-cooled reactor of this invention reduces the temperature of the central hot spot by filling graphite spheres and fuel spheres in sections, thus avoiding safety hazards caused by excessively high temperatures of fuel elements in the central region. The heterogeneous structure allows the fuel spheres to more fully utilize their heat output, improving overall power generation efficiency. The spherical fuel elements (i.e., graphite spheres and fuel spheres) are filled from the top of the core and move downwards under gravity, enabling non-stop refueling of the reactor and improving the utilization rate of rated power.

[0010] In some embodiments, the ball conveying and distributing assembly includes a conveying section, a main conveying pipe, a first sub-pipe, and a second sub-pipe. The ball inlet and ball outlet are arranged on the conveying section. The main conveying pipe connects the ball unloading pipe and the ball inlet. The first sub-pipe connects the first filling area and the ball outlet. The second sub-pipe connects the second filling area and the ball outlet.

[0011] In some embodiments, the conveying and separating assembly further includes a separation section having a separation inlet and a separation outlet. The separation inlet is connected to the ball outlet, and the separation outlet is connected to the first sub-tube and the second sub-tube. The separation section is used to separate the graphite balls and the fuel balls and then pass them into the first filling area and the second filling area through the first sub-tube and the second sub-tube, respectively.

[0012] In some embodiments, there are multiple second sub-tubes, which are arranged at circumferential intervals along the first sub-tube.

[0013] In some embodiments, the ball-falling velocity of the first sub-tube is greater than that of the second sub-tube.

[0014] In some embodiments, the volume of the first filling region is smaller than the volume of the second filling region.

[0015] The present invention discloses a method for loading a heterogeneous quasi-static core of a pebble bed high-temperature gas-cooled reactor, wherein the loading method is performed according to the heterogeneous quasi-static core loading system of the pebble bed high-temperature gas-cooled reactor described in any of the above embodiments, and is characterized by comprising the following steps:

[0016] The equivalent volume of the pebble bed in the pebble bed reactor is determined, and the total number of fuel elements is calculated based on the equivalent volume. The fuel elements include graphite spheres and fuel balls.

[0017]

[0018] Among them, V PB V is the equivalent volume of the ball bed. FE Let ε be the volume of a single fuel element, ε be the porosity of the naturally packed spherical bed, and N be the total number of fuel elements.

[0019] Determine the number of new fuel elements to be added to the pebble bed reactor each day, and obtain the safe limits for the temperature at the center of the pebble bed reactor.

[0020] Adjusting the dropping speed of graphite spheres and fuel spheres ensures that the graphite spheres and fuel spheres are in the core loading configuration and maintains the pebble bed reactor in a dynamic circulation state.

[0021] In some embodiments, determining the number of new fuel elements to be added to the pebble bed reactor each day further includes the following steps:

[0022] Calculated based on the average residence time of fuel elements in the reactor core and the total number of fuel elements:

[0023]

[0024] Where, N fresh The number of new fuel elements introduced each day is denoted by t, and the average fuel residence time is t.

[0025] In some embodiments, the heterogeneous quasi-static core loading method for a pebble bed high-temperature gas-cooled reactor according to the present invention further includes the following step: the average fuel residence time is determined based on the enrichment of fuel elements and the power of the pebble bed reactor. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the heterogeneous quasi-static core loading system of a pebble bed type high-temperature gas-cooled reactor according to an embodiment of the present invention.

[0027] Figure 2 This is an internal schematic diagram of the pebble bed reactor of the heterogeneous quasi-static core loading system of the pebble bed high-temperature gas-cooled reactor according to an embodiment of the present invention.

[0028] Figure 3 This is a cross-sectional schematic diagram of the pebble bed reactor in the heterogeneous quasi-static core loading system of the pebble bed high-temperature gas-cooled reactor according to an embodiment of the present invention.

[0029] Figure 4 This is a schematic diagram of reactor criticality at 200MW power for a heterogeneous quasi-static core loading system of a pebble bed type high-temperature gas-cooled reactor according to an embodiment of the present invention.

[0030] Figure 5This is a schematic diagram of reactor criticality at 250MW power for the heterogeneous quasi-static core loading system of the pebble bed high-temperature gas-cooled reactor according to an embodiment of the present invention.

[0031] Figure label:

[0032] 100. Graphite spheres; 200. Fuel spheres.

[0033] 1. Pellet bed reactor; 11. First filling zone; 12. Second filling zone; 13. Inlet pipe; 14. Outlet pipe.

[0034] 2. Conveying and separating ball assembly; 21. Conveying section; 22. Conveying main pipe; 23. First sub-pipe; 24. Second sub-pipe; 25. Separating section. Detailed Implementation

[0035] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0036] like Figures 1-5 As shown, the heterogeneous quasi-static core loading system of the pebble bed high-temperature gas-cooled reactor of this embodiment includes: a pebble bed reactor 1 and a pebble delivery assembly 2.

[0037] The core of the pebble bed reactor 1 has a filling region. An inlet pipe 13 is located at the upper end of the pebble bed reactor 1, and an outlet pipe 14 is located at the lower end. Both the inlet pipe 13 and the outlet pipe 14 are connected to the filling region. The filling region includes a first filling region 11 and a second filling region 12. The first filling region 11 is located in the middle of the filling region, and the second filling region 12 surrounds the first filling region 11 circumferentially, and extends along the height direction of the pebble bed reactor 1 (e.g., in the direction of height). Figure 1 In the vertical direction, the first filling zone 11 is arranged correspondingly to the unloading pipe 14. The conveying and separating ball assembly 2 has an inlet and an outlet. The inlet is connected to the unloading pipe 14, and the outlet is connected to the inlet pipe 13, for receiving and separating the graphite balls 100 and fuel balls 200 discharged from the unloading pipe 14, and passing the separated graphite balls 100 into the first filling zone 11, and passing the fuel balls 200 into the second filling zone 12.

[0038] Specifically, such as Figures 1-3As shown, the core filling area is connected to external equipment via a feed pipe 13 and a discharge pipe 14. The filling area is used to fill fuel elements (graphite balls 100 and fuel balls 200), with the first filling area 11 located in the center and the second filling area 12 surrounding it. The first filling area 11 and the discharge pipe 14 are arranged vertically, with the first filling area 11 located above the discharge pipe 14. The feed port of the conveying and distributing assembly 2 is connected to the discharge pipe 14, and the discharge port is connected to the feed pipe 13. The conveying and distributing assembly 2 receives the graphite balls 100 and fuel balls 200 discharged from the discharge pipe 14, separates them, and then fills the first filling area 11 and the second filling area 12, respectively.

[0039] Understandably, due to the use of a zoned filling method, the first filling zone 11 is mainly filled with graphite spheres 100, which can effectively reduce the temperature of the central hot spot, thereby reducing the central temperature of the fuel element and improving safety. The second filling zone 12 is mainly filled with fuel spheres 200, which can increase the core's heat output and improve power generation efficiency. The conveying and separating assembly 2 realizes the separation of graphite spheres 100 and fuel spheres 200, allowing them to enter their respective filling zones, thus ensuring the heterogeneous structure of the core.

[0040] In other words, the heterogeneous quasi-static core loading system of the pebble bed high-temperature gas-cooled reactor of this invention reduces the temperature of the central hot spot by filling graphite spheres 100 and fuel spheres 200 in sections, thus avoiding safety hazards caused by excessively high temperatures of fuel elements in the central region. The heterogeneous structure allows the fuel spheres 200 to more fully utilize their heat output, improving overall power generation efficiency. The spherical fuel elements (i.e., graphite spheres 100 and fuel spheres 200) are filled from the top of the core and move downwards by gravity, enabling non-stop refueling of the reactor, which is beneficial for improving the utilization rate of rated power.

[0041] In addition, the partitioned filling method can adjust the ratio of graphite spheres 100 and fuel spheres 200 according to different operational needs, so as to achieve flexible adjustment of the reactor core.

[0042] In some embodiments, the ball conveying and distributing assembly 2 includes a conveying section 21, a main conveying section 22, a first sub-pipe 23, and a second sub-pipe 24. The ball inlet and the ball outlet are arranged on the conveying section 21. The main conveying section 22 connects the ball unloading pipe 14 to the ball inlet. The first sub-pipe 23 connects the first filling area 11 and the ball outlet. The second sub-pipe 24 connects the second filling area 12 and the ball outlet.

[0043] Specifically, such as Figures 1-3As shown, the conveying section 21 includes an inlet and an outlet. The main function of the conveying section 21 is to receive graphite balls 100 and fuel balls 200 from the unloading pipe 14, facilitating subsequent separation of the mixed graphite balls 100 and fuel balls 200, and providing power to transport the separated graphite balls 100 and fuel balls 200 to the filling area. One end of the main conveying pipe 22 is connected to the unloading pipe 14, and the other end is connected to the inlet of the conveying section 21. The main conveying pipe 22 is responsible for conveying the graphite balls 100 and fuel balls 200 from the unloading pipe 14 to the conveying section 21. One end of the first sub-pipe 23 is connected to the outlet on the conveying section 21, and the other end is connected to the first filling area 11. The function of the first sub-pipe 23 is to transport the separated graphite balls 100 to the first filling area 11. One end of the second sub-pipe 24 is connected to the outlet on the conveying section 21, and the other end is connected to the second filling area 12. The function of the second sub-tube 24 is to transport the separated fuel balls 200 to the second filling zone 12.

[0044] Understandably, the conveying unit 21 can be a pneumatic conveying device to convey fuel elements. After the reactor has been operating for a period of time, some graphite spheres 100 and fuel spheres 200 need to be unloaded from the core. These spheres are discharged through the unloading pipe 14 and enter the main conveying pipe 22. The incoming spheres are separated using some separation equipment (such as mechanical separation devices, screening devices, or other separation methods). The separated graphite spheres 100 are conveyed to the first filling zone 11 through the first sub-pipe 23, while the fuel spheres 200 are conveyed to the second filling zone 12 through the second sub-pipe 24.

[0045] Therefore, this partitioned filling method ensures the heterogeneous structure of the reactor core, with the central region filled with graphite spheres 100 to reduce the temperature of the central hot spot, and the surrounding region filled with fuel spheres 200 to improve thermal efficiency. The design of the inlet and outlet allows the entire sphere assembly to be operated continuously, improving refueling efficiency and reactor operational continuity.

[0046] In some embodiments, the conveying and separating ball assembly 2 further includes a separation section 25, which has a separation inlet and a separation outlet. The separation inlet is connected to the ball outlet, and the separation outlet is connected to the first sub-tube 23 and the second sub-tube 24. The separation section 25 is used to separate the graphite ball 100 and the fuel ball 200 and then pass them into the first filling area 11 and the second filling area 12 through the first sub-tube 23 and the second sub-tube 24, respectively.

[0047] Specifically, such as Figures 1-3As shown, the separation inlet is connected to the ball outlet of the conveying section 21, receiving the mixed flow from the conveying section 21, i.e., the airflow containing graphite balls 100 and fuel balls 200. There are usually two or more separation outlets, which are connected to the first sub-pipe 23 and the second sub-pipe 24 respectively. Each separation outlet is responsible for conveying a specific type of ball (graphite ball 100 or fuel ball 200) to the corresponding sub-pipe.

[0048] It is understood that the main body of the separation section 25 may contain one or more separation mechanisms, such as a screen, cyclone separator, vibrating screen, or other types of separation devices. The separation mechanisms are designed to separate the graphite balls 100 and fuel balls 200 based on their physical characteristics (such as size, weight, shape, etc.).

[0049] Preferably, the separation section 25 can be a fuel consumption measurement system, that is, by separating the spheres containing nuclear fuel and those without nuclear fuel, the graphite spheres 100 and fuel spheres 200 mixed after passing through the separation section 25 are separated.

[0050] In other words, the separation section 25 can efficiently separate the graphite spheres 100 and the fuel spheres 200, ensuring partitioned core filling and thus optimizing reactor performance and safety. Of course, the design of the separation section 25 can be adjusted according to actual needs to adapt to different types of pebble bed high-temperature gas-cooled reactors.

[0051] In some embodiments, there are multiple second sub-tubes 24, and the multiple second sub-tubes 24 are arranged at circumferential intervals along the first sub-tube 23.

[0052] Specifically, such as Figures 1-3 As shown, the first sub-tube 23 is a single pipe responsible for transporting the separated graphite spheres 100 to the first filling region 11 of the reactor core. There are multiple second sub-tubes 24, evenly distributed circumferentially along the first sub-tube 23, and each second sub-tube 24 is responsible for transporting the separated fuel spheres 200 to its corresponding second filling region 12. The spacing of the second sub-tubes 24 can be varied; for example, they can be distributed at equal angular intervals around the first sub-tube 23, or their layout can be optimized according to the requirements of the reactor core design.

[0053] Understandably, the design of multiple second sub-tubes 24 enables the distributed delivery of fuel pellets 200, facilitating a uniform distribution of the fuel pellets 200 in the second filling zone 12, thereby improving the thermodynamic performance and operating efficiency of the reactor core. Each second sub-tube 24 can be independently controlled, allowing operators to adjust the delivery rate of fuel pellets 200 based on the thermodynamic characteristics or operating status of the reactor core to optimize reactor performance. By arranging multiple second sub-tubes 24 at intervals, flow balance can also be achieved within the second filling zone 12, reducing the problem of localized overheating of the reactor core due to localized flow overload.

[0054] In some embodiments, the ball drop speed of the first sub-tube 23 is greater than the ball drop speed of the second sub-tube 24.

[0055] Understandably, the first filling zone 11 of the reactor core is typically filled with graphite spheres 100, whose main functions are to moderate and reflect neutrons, and to reduce the temperature of the central hot spot. The graphite sphere 100 filling zone has a large heat capacity, therefore a faster sphere drop velocity is required to ensure a sufficient supply of graphite spheres 100 to meet thermodynamic requirements. Furthermore, the graphite spheres 100, acting as a moderator and reflector layer, are crucial for maintaining the stability and safety of the reactor core. A faster sphere drop velocity ensures that the graphite spheres 100 in the first filling zone 11 can be replenished in a timely manner during core operation to maintain the homogeneity of the core and the dynamic balance of the core sphere flow. The spheres in the middle drop zone drop faster, forming a sphere-stacking shape.

[0056] The first filling zone 11 is located in the middle of the core, while the second filling zone 12 is located around the first filling zone 11 and has multiple second sub-tubes 24 arranged accordingly. The amount of graphite balls falling from the second filling zone 12 is larger than that falling from the first sub-tube 23. Therefore, in order to form a heterogeneous structure of graphite balls 100 in the middle and fuel balls 200 on the outer side in the filling zone, the falling speed of the graphite balls 100 needs to be faster than the feeding speed of the fuel balls 200.

[0057] Furthermore, the high falling velocity of the graphite balls in the first tube 23, and the high falling velocity of the graphite balls 100, means they can reach the first filling zone 11 more quickly. This facilitates rapid filling of the area above the unloading tube with graphite balls, ensuring the stability of the overall circulation structure of the recirculating reactor. This prevents the inability to stably maintain a heterogeneous core due to excessively fast unloading velocity of the graphite balls in the center of the reactor. In other words, if the unloading velocity of the graphite balls in the center of the reactor is too fast, the fuel balls are more likely to move towards the location of the graphite balls, causing the first filling zone in the center of the core to be filled with fuel balls, affecting the core temperature.

[0058] In some embodiments, the volume of the first filling region 11 is smaller than the volume of the second filling region 12.

[0059] It is understandable that, such as Figures 1-3 As shown, the thermodynamic performance requirements of the reactor core necessitate different heat generation and dissipation characteristics in different regions of the core. The smaller volume of the first filling region 11 (typically filled with graphite spheres 100) allows for a reduction in fuel sphere enrichment while ensuring core criticality. In other words, a smaller first filling region 11 helps reduce the power density at the core center, thereby lowering the temperature of the central hotspot and improving reactor safety.

[0060] The following describes a heterogeneous quasi-static core loading method for a pebble bed type high-temperature gas-cooled reactor according to an embodiment of the present invention.

[0061] The heterogeneous quasi-static core loading method for a pebble bed type high-temperature gas-cooled reactor according to embodiments of the present invention is completed according to the heterogeneous quasi-static core loading system of any of the above embodiments for a pebble bed type high-temperature gas-cooled reactor, characterized by comprising the following steps:

[0062] Determine the equivalent volume of the pebble bed in pebble bed reactor 1, and calculate the total number of fuel elements based on the equivalent volume. The fuel elements include graphite spheres 100 and fuel spheres 200.

[0063]

[0064] Among them, V PB V is the equivalent volume of the ball bed. FE Let ε be the volume of a single fuel element, ε be the porosity of the naturally packed pebble bed, and N be the total number of fuel elements.

[0065] Understandably, the formula above can be used to determine how many fuel elements are needed to fill the equivalent volume of the entire pebble bed.

[0066] Determine the number of new fuel elements to be added to pebble reactor 1 each day and obtain the safe limits for temperature at the center of pebble reactor 1. Based on the reactor's operating plan and fuel consumption rate, determine the number of new fuel elements required to be added to the core each day. This typically involves planning the fuel cycle and monitoring the core power level.

[0067] The center temperature of the fuel elements in the middle of the reactor core is an important safety parameter. It is necessary to determine a safe limit for this temperature to ensure that the reactor does not exceed this temperature during operation, thereby preventing fuel element damage or radioactive material leakage.

[0068] The dropping velocities of graphite spheres 100 and fuel spheres 200 are adjusted to ensure their dynamic circulation in the core loading configuration and to maintain the pebble bed reactor 1. By adjusting the dropping velocities of the graphite spheres 100 and fuel spheres 200, their distribution and filling within the core can be controlled. This helps maintain the dynamic circulation state of the core, meaning that the graphite spheres 100 and fuel spheres 200 can continuously fill from the top of the core and move downwards under gravity, achieving refueling without stopping the reactor.

[0069] In some embodiments, determining the number of new fuel elements fed into pebble bed reactor 1 per day further includes the following steps:

[0070] Calculated based on the average residence time of fuel elements in the reactor core and the total number of fuel elements:

[0071]

[0072] Where, N freshLet t be the number of new fuel elements added each day, and t be the average fuel residence time. This formula determines the number of new fuel elements needed daily to maintain fuel cycling and power output in the reactor core.

[0073] In some embodiments, the heterogeneous quasi-static core loading method of the pebble bed high-temperature gas-cooled reactor of the present invention further includes the following step: the average fuel residence time is determined based on the enrichment of fuel elements and the power of the pebble bed reactor 1.

[0074] It is understandable that, such as Figures 1-5 As shown, when the equivalent volume V of the ball bed PB It is 77.8m 3 When left and right, V FE This refers to the volume of a single fuel element, typically taken as 1.13 x 10⁻⁶. -4 m 3 (Using a sphere with a diameter of 6cm); ε is taken as 0.61. According to the above formula, the total number of fuel elements N in the reactor core can be calculated to be approximately 420,000.

[0075] like Figure 4 and Figure 5 As shown, if the fuel element (U235) enrichment is 15%, then a reactor power output between 200MW and 250MW and a mean fuel residence time between 50.5 and 65 days can maintain reactor criticality. The number of new fuel elements N introduced daily can be calculated using Formula 2. fresh The number ranges from 6461 to 8317.

[0076] Therefore, by precisely controlling the enrichment and residence time of fuel elements, a stable power output of the reactor core can be maintained, avoiding excessive power fluctuations. Based on the fuel element enrichment and core power, the optimal fuel residence time can be calculated, thereby optimizing fuel consumption and extending fuel lifespan. Precise control of fuel element residence time can also reduce the risk of fuel element overheating and improve reactor safety.

[0077] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0078] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0079] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0080] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0081] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0082] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A heterogeneous quasi-static core loading system for a pebble bed type high-temperature gas-cooled reactor, characterized in that, include: A pebble bed reactor has a core with a filling region. An inlet pipe is located at the upper end of the pebble bed reactor, and an outlet pipe is located at the lower end. Both the inlet pipe and the outlet pipe are connected to the filling region. The filling region includes a first filling region and a second filling region. The first filling region is located in the middle of the filling region, and the second filling region surrounds the first filling region circumferentially. Furthermore, in the height direction of the pebble bed reactor, the first filling region and the outlet pipe are arranged correspondingly. A ball conveying and separating assembly has an inlet and an outlet. The inlet is connected to the unloading pipe, and the outlet is connected to the inlet pipe, for receiving and separating graphite balls and fuel balls discharged from the unloading pipe, and for passing the separated graphite balls into the first filling area and the fuel balls into the second filling area.

2. The heterogeneous quasi-static core loading system for a pebble bed type high-temperature gas-cooled reactor according to claim 1, characterized in that, The ball conveying and distributing assembly includes a conveying section, a main conveying pipe, a first sub-pipe, and a second sub-pipe. The ball inlet and ball outlet are arranged on the conveying section. The main conveying pipe connects the ball unloading pipe and the ball inlet. The first sub-pipe connects the first filling area and the ball outlet. The second sub-pipe connects the second filling area and the ball outlet.

3. The heterogeneous quasi-static core loading system for a pebble bed type high-temperature gas-cooled reactor according to claim 2, characterized in that, The conveying and separating assembly further includes a separation section, which has a separation inlet and a separation outlet. The separation inlet is connected to the ball outlet, and the separation outlet is connected to the first sub-tube and the second sub-tube. The separation section is used to separate the graphite balls and the fuel balls and then pass them into the first filling area and the second filling area through the first sub-tube and the second sub-tube, respectively.

4. The heterogeneous quasi-static core loading system for a pebble bed type high-temperature gas-cooled reactor according to claim 3, characterized in that, There are multiple second sub-tubes, which are arranged at intervals along the circumference of the first sub-tube.

5. The heterogeneous quasi-static core loading system for a pebble bed type high-temperature gas-cooled reactor according to claim 4, characterized in that, The ball falling speed of the first sub-tube is greater than that of the second sub-tube.

6. The heterogeneous quasi-static core loading system for a pebble bed type high-temperature gas-cooled reactor according to claim 5, characterized in that, The volume of the first filling region is smaller than the volume of the second filling region.

7. A method for loading a heterogeneous quasi-static core of a pebble bed high-temperature gas-cooled reactor, wherein the loading method is performed using the heterogeneous quasi-static core loading system for the pebble bed high-temperature gas-cooled reactor according to any one of claims 1-6, characterized in that... Includes the following steps: The equivalent volume of the pebble bed in the pebble bed reactor is determined, and the total number of fuel elements is calculated based on the equivalent volume. The fuel elements include graphite spheres and fuel balls. Among them, V PB V is the equivalent volume of the ball bed. FE Let ε be the volume of a single fuel element, ε be the porosity of the naturally packed spherical bed, and N be the total number of fuel elements. Determine the number of new fuel elements to be added to the pebble bed reactor each day, and obtain the safe limits for the temperature at the center of the pebble bed reactor. Adjusting the dropping speed of graphite spheres and fuel spheres ensures that the graphite spheres and fuel spheres are in the core loading configuration and maintains the pebble bed reactor in a dynamic circulation state.

8. The heterogeneous quasi-static core loading system for a pebble bed type high-temperature gas-cooled reactor according to claim 8, characterized in that, Determining the number of new fuel elements to be added to the pebble bed reactor each day also includes the following steps: Calculated based on the average residence time of fuel elements in the reactor core and the total number of fuel elements: Where, N fresh The number of new fuel elements introduced each day is denoted by t, and the average fuel residence time is t.

9. The heterogeneous quasi-static core loading system for a pebble bed type high-temperature gas-cooled reactor according to claim 8, characterized in that, It also includes the following steps: The average fuel residence time is determined based on the enrichment of fuel elements and the power of the pebble bed reactor.

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