A helium-xenon cooled microreactor system

Abstract

The application discloses a helium-xenon cooled micro reactor system, which comprises a reactor core subsystem and a Brayton cycle subsystem; the reactor core subsystem is horizontally arranged and is provided with a rotating shaft penetrating the core axis; the Brayton cycle subsystem comprises a turbine, a regenerator, a cooler and a compressor; the turbine is arranged at the fluid outlet end of the reactor core; the regenerator and the cooler are coaxially sleeved with the reactor core, the regenerator is sleeved with the outer side wall of the reactor core, and the cooler is sleeved with the outer side wall of the regenerator; the compressor is arranged at the closed end opposite to the fluid outlet end of the reactor core; the compressor, the reactor core and the turbine are sequentially arranged along the axial direction of the reactor core, and the rotating shaft is connected with the compressor, the reactor core and the turbine. The helium-xenon cooled micro reactor system integrates the functions of heat and electricity conversion and shielding, and can realize the miniaturization and light weight of the reactor system.

Description

Technical Field

[0001] This invention relates to the field of nuclear energy, and more specifically to a helium-xenon cooled microreactor system. Background Technology

[0002] Microreactors are plug-and-play small reactors with a power output of less than 20MW. They are easy to assemble and can be transported by road, rail, and air. They can provide strong support for stable energy supply in deep space and deep sea exploration, as well as remote areas, and can also power propulsion systems. Due to their advantages, the development of microreactors has attracted widespread attention from countries around the world, especially nuclear power-developed countries such as the United States and Russia. Since the 1960s, various types of microreactor systems have been proposed.

[0003] Currently, relatively systematic research has been conducted on the design and development of microreactors. To maximize the application capabilities of microreactors while ensuring radiation safety, their weight and volume should be minimized. Lightweighting and miniaturization are the design goals of microreactor systems. However, in practice, neutrons and gamma rays are uncharged particles, posing significant challenges to shielding. To meet radioactivity requirements, appropriate shielding layers need to be arranged around the reactor system. For gamma rays, high-density heavy metal materials or organic materials containing heavy metals, such as tungsten, lead, lead-boron polyethylene, etc., are required, inevitably increasing the weight and volume of the microreactor system. Shielding design has become a difficult point in microreactor design research. Summary of the Invention

[0004] This invention addresses the shortcomings of existing technologies where ensuring reactor radiation safety inevitably increases the weight and volume of microreactor systems by providing a helium-xenon cooled microreactor system.

[0005] The present invention solves the above-mentioned technical problems through the following technical solution:

[0006] This invention provides a helium-xenon cooled microreactor system, which includes a core subsystem and a Brayton cycle subsystem.

[0007] The core subsystem is arranged laterally and is equipped with a rotating shaft that passes through the core axis;

[0008] The Brayton cycle subsystem includes a turbine, a regenerator, a cooler, and a compressor;

[0009] The turbine is located at the fluid outlet end of the reactor core; the regenerator and the cooler are coaxially sleeved with the reactor core, the regenerator is sleeved with the outer wall of the reactor core, and the cooler is sleeved with the outer wall of the regenerator.

[0010] The compressor is located at the sealed end opposite the fluid outlet end of the reactor core.

[0011] The compressor, the reactor core, and the turbine are arranged sequentially along the axial direction of the reactor core, and the rotating shaft connects the compressor, the reactor core, and the turbine in series.

[0012] In this technical solution, the reactor core subsystem is arranged laterally for easy transportation. The compressor, reactor core, and turbine are arranged sequentially along the axial direction of the reactor core, forming a three-in-one structure. The regenerator is fitted onto the outer wall of the reactor core, and the cooler is fitted onto the outer wall of the regenerator, forming a reactor system integrating thermoelectric conversion and shielding functions. Eliminating the need for a shielding layer significantly reduces the size of the reactor system, making it miniaturized, compact, and lightweight. Preferably, along the axial direction of the reactor core, the turbine is also connected to the generator set's motor via a shaft for driving power generation.

[0013] Preferably, the regenerator is a spiral plate heat exchanger, which includes a first heat exchange channel and a second heat exchange channel. The first heat exchange channel is disposed on the outer side wall of the core, and the second heat exchange channel is stacked on the outer side wall of the first heat exchange channel. The first heat exchange channel and the second heat exchange channel together form a spiral channel around the core.

[0014] In this technical solution, a spiral plate heat exchanger is used, which combines heat exchange with shielding of the reactor core's radial neutrons and gamma rays. It includes a first heat exchange channel and a second heat exchange channel, which can efficiently achieve heat exchange.

[0015] Preferably, the first heat exchange channel and the second heat exchange channel meet one or more of the following conditions;

[0016] The first heat exchange channel and the second heat exchange channel are each independently provided with equidistant fixed-distance columns; in this technical solution, setting fixed-distance columns can increase the heat exchange area in the channel and improve the heat exchange effect.

[0017] The channel spacing between the first heat exchange channel and the second heat exchange channel is 10-20 mm each independently;

[0018] The number of windings of the first heat exchange channel and the second heat exchange channel is independently 4 to 10 layers, preferably 4 layers;

[0019] The sidewall thickness of the first heat exchange channel and the second heat exchange channel is 3 mm each independently;

[0020] The first and second heat exchange channels are made of GH3535 alloy.

[0021] Preferably, the diameter of the spacer column is 10 mm and the distance between the spacer columns is 25 mm.

[0022] Preferably, the cooler is an annular shell-and-tube heat exchanger, the interior of which includes a gas pipe that spirals around the regenerator. The shell of the annular shell-and-tube heat exchanger is fitted onto the regenerator to form a cavity, which surrounds the gas pipe for the flow of coolant fluid.

[0023] In this technical solution, the cooler is an annular sleeve heat exchanger, which combines heat exchange and shielding of the reactor core's radial neutrons and gamma rays. It includes a gas pipe for cooling the hot fluid coming out of the first heat exchange channel. Water is used as the cooling liquid in the coolant chamber to facilitate the removal of residual heat.

[0024] Preferably, the annular shell-and-tube heat exchanger meets one or more of the following conditions;

[0025] The diameter of the annular sleeve heat exchanger is 10cm-30cm, preferably 30cm;

[0026] The sleeve thickness of the annular sleeve heat exchanger is 2-5mm, preferably 3mm;

[0027] The diameter of the gas pipe is 20-30 mm, preferably 25 mm;

[0028] The thickness of the gas pipeline is 2.5 mm.

[0029] Preferably, the first heat exchange channel has a hot fluid inlet at the fluid outlet end of the reactor core for communicating with the outlet of the turbine; the first heat exchange channel has a hot fluid outlet at the sealed end of the reactor core.

[0030] The inlet of the gas pipe is connected to the hot fluid outlet of the first heat exchange channel, and is used to cool the hot fluid coming out of the first heat exchange channel.

[0031] The compressor has an inlet at the sealed end away from the core, and is connected to the outlet of the gas pipeline;

[0032] The second heat exchange channel is provided with a cold fluid inlet at the sealed end of the reactor core;

[0033] The compressor outlet is located at one end near the sealed end of the core and is connected to the cold fluid inlet of the second heat exchange channel.

[0034] The second heat exchange channel is provided with a cold fluid outlet at the fluid outlet end of the reactor core;

[0035] The cold fluid outlet of the second heat exchange channel is connected to the fluid inlet of the core subsystem.

[0036] In this technical solution, the fluid in the core subsystem flows into the turbine from the fluid outlet end of the core subsystem, then flows into the hot fluid inlet of the first heat exchange channel from the turbine outlet, then flows into the gas pipe inlet of the cooler from the hot fluid outlet of the first heat exchange channel, then flows into the compressor inlet from the gas pipe outlet, then flows into the cold fluid inlet of the second heat exchange channel from the compressor outlet, and finally flows back to the fluid inlet end of the core subsystem from the cold fluid outlet of the second heat exchange channel, thus entering the core.

[0037] Preferably, the core subsystem includes, from the axis outwards, a rotating shaft channel, a core active region, a reflector layer, and a shell; wherein,

[0038] The active core region includes a moderator matrix that fills the active core region, and the moderator matrix is ​​provided with a plurality of fuel rods and a plurality of coolant conduits along the circumferential direction of the axis.

[0039] The reflective layer contains several control drums.

[0040] Preferably, the space between the reflector layer and the shell forms a first cavity, and the space between the two end faces of the shell and the moderator matrix forms a second cavity. The first cavity, the second cavity, and the coolant pipe are interconnected. The shell is provided with a fluid inlet end and a fluid outlet end of the reactor core subsystem.

[0041] In this technical solution, the cold fluid outlet is connected to the first cavity, which in turn connects the second heat exchange channel to the first cavity. The cold fluid flowing out of the second heat exchange channel flows into the first cavity, then into the second cavity, and finally into the coolant pipe to complete the fluid circulation.

[0042] Preferably, the core subsystem meets one or more of the following conditions;

[0043] The moderator matrix is ​​made of graphite; it is used to moderate neutrons and to fix the fuel rods and coolant pipes.

[0044] The diameter of the rotating shaft channel is 5cm-10cm, preferably 10cm;

[0045] The sidewall thickness of the rotating shaft channel is 2cm-5cm, preferably 2cm;

[0046] The sidewall material of the rotating shaft channel is boron-containing polyethylene;

[0047] The diameter of the active region in the reactor core is 50-80 cm, preferably 60 cm;

[0048] The length of the active region in the reactor core is 40-60 cm, preferably 50 cm;

[0049] The diameter of the fuel rod is 10-20 mm, preferably 15 mm;

[0050] The fuel rods are fueled by uranium carbide fuel with an enrichment of ≤20%, preferably with a density of 13.6 g / cm³. 3 It belongs to the category of fuels that use high-density, high-thermal-conductivity uranium carbide fuel;

[0051] Preferably, each fuel rod is surrounded by six coolant pipes arranged in a hexagonal pattern; the distance between the center of the fuel rod and the center of the coolant pipe is 13-17 mm, preferably 15 mm; in this technical solution, the uniformly arranged coolant pipes can achieve efficient cooling.

[0052] The fuel enrichment of the active region of the reactor core is divided into three zones along the axis outward, namely 5-10%, 19.75%, and 5-10%, respectively; this is used to improve neutron economy while reducing the neutron flux in the core shaft channel.

[0053] The channel diameter of the coolant is 4-10 mm, preferably 5 mm;

[0054] The thickness of the coolant channel is 0.2–0.5 mm, preferably 0.2 mm;

[0055] The sidewall material of the coolant pipe is SiC;

[0056] The coolant is a helium-xenon mixture; preferably, the proportion of Xe in the helium-xenon mixture is 8% to 30%, and the molecular weight of the mixture is 15 to 42 g / mol.

[0057] The number of control drums is 8;

[0058] The diameter of the control drum is 5-7 cm, preferably 5.75 cm;

[0059] The control drum is a cylinder, and the neutron absorbing material in the control drum is disposed on the side wall of the cylinder. The length is the length of a 60° arc along the circumference of the cylinder, the height is the height of the cylinder, and the thickness is 0.6-1.2cm, preferably 0.8cm.

[0060] In this technical solution, the control drum is used for core reactivity control and core start-up and shutdown.

[0061] The neutron-absorbing material of the control drum is B4C;

[0062] In this technical solution, the B4C layer in the control drum can rotate freely around a circle with a diameter of 5.75. When the reactor is running, the B4C layer turns outward from the core. When the reactor is shut down in an emergency, the B4C layer turns outward to the active region of the core to absorb neutrons, thereby reducing the reactivity of the core below the critical level.

[0063] The thickness of the reflective layer is 15-30cm, preferably 20cm;

[0064] The material of the reflective layer is BeO;

[0065] The thickness of the channel in the first cavity is 1.5-3cm, preferably 2cm;

[0066] The core consolidation rate is 1 to 5 MW, preferably 5 MW;

[0067] The diameter and height of the reactor core are 25-50 cm.

[0068] Based on common knowledge in the field, the above-mentioned preferred conditions can be combined arbitrarily to obtain various preferred embodiments of the present invention.

[0069] The reagents and raw materials used in this invention are all commercially available.

[0070] The significant advantages of this invention are as follows: the transverse arrangement of the core subsystem facilitates transportation; the compressor, core, and turbine are arranged sequentially along the core's axial direction, forming a three-in-one structure; the regenerator is fitted to the outer wall of the core, and the cooler is fitted to the outer wall of the regenerator, forming a reactor system integrating thermoelectric conversion and shielding functions. Eliminating the need for a shielding layer greatly reduces the reactor system's volume, enabling miniaturization, miniaturization, and weight reduction. Furthermore, under the same conditions, compared to traditional Brayton cycle distributed reactor systems, the neutron and gamma doses can be reduced by two orders of magnitude, and the amount of shielding material required can be reduced by one order of magnitude. Attached Figure Description

[0071] Figure 1 This is a schematic diagram of the structure of a helium-xenon cooled microreactor system according to a preferred embodiment of the present invention.

[0072] Figure 2 This is a radial cross-sectional view of the core subsystem of a preferred embodiment of the present invention.

[0073] Figure 3 This is a schematic diagram of the core active region of a preferred embodiment of the present invention.

[0074] Figure 4 This is an axial schematic diagram of the regenerator according to a preferred embodiment of the present invention.

[0075] Figure 5 This is a radial cross-sectional view of the regenerator according to a preferred embodiment of the present invention.

[0076] Figure 6 This is a schematic diagram of the structure of a cooler according to a preferred embodiment of the present invention.

[0077] Explanation of reference numerals in the attached figures:

[0078] Core 1; Shaft passage 11, Core active zone 12, Fuel rods 121, Coolant ducts 122; Radar layer 13, Control drum 131; Shell 14; First cavity 15; Second cavity 16; Moderator matrix 17;

[0079] Shaft 2;

[0080] Turbine 3;

[0081] Regenerator 4; First heat exchange channel 41, second heat exchange channel 42, spacer column 43, hot fluid inlet 44, hot fluid outlet 45, cold fluid inlet 46, cold fluid outlet 47;

[0082] Cooler 5; Gas pipe 51, gas pipe inlet 52, gas pipe outlet 53, coolant inlet 54, coolant outlet 55;

[0083] Compressor 6;

[0084] Generator 7;

[0085] Water-air heat exchanger 8. Detailed Implementation

[0086] The present invention is further illustrated below by way of preferred embodiments, but the invention is not limited to the scope of the embodiments described herein. Experimental methods not specifically described in the following embodiments are performed according to conventional methods and conditions, or as selected in accordance with the product instructions.

[0087] This embodiment provides a helium-xenon cooled microreactor system, which includes a core subsystem and a Brayton cycle subsystem.

[0088] like Figure 1 As shown, the reactor core subsystem is arranged horizontally and is provided with a rotating shaft 2 that passes through the axis of reactor core 1;

[0089] The Brayton cycle subsystem includes turbine 3, regenerator 4, cooler 5, and compressor 6;

[0090] Turbine 3 is located at the fluid outlet end of core 1; regenerator 4 and cooler 5 are coaxially sleeved with core 1, regenerator 4 is sleeved with the outer wall of core 1, and cooler 5 is sleeved with the outer wall of regenerator 4.

[0091] The compressor 6 is located at the sealed end opposite the fluid outlet end of the reactor core 1.

[0092] The compressor 6, the core 1 and the turbine 3 are arranged sequentially along the axial direction of the core 1, and the shaft 2 connects the compressor 6, the core 1 and the turbine 3 in series.

[0093] In this embodiment, the core subsystem is arranged laterally for easy transportation. The compressor 6, core 1, and turbine 3 are arranged sequentially along the axial direction of core 1, forming a three-in-one structure. The regenerator 4 and cooler 5 are coaxially fitted with core 1. The regenerator 4 is fitted with the outer wall of core 1, and the cooler 5 is fitted with the outer wall of regenerator 4, forming a reactor system that integrates thermoelectric conversion and shielding functions. The use of the shielding layer is eliminated, which can greatly reduce the volume of the reactor system, making it as miniaturized and lightweight as possible.

[0094] Preferably, the helium-xenon cooled microreactor system further includes a generator 7, a compressor 6, a reactor core 1, a turbine 3, and a generator 7 arranged sequentially along the axial direction of the reactor core 1, with a rotating shaft 2 connecting the compressor 6, reactor core 1, turbine 3, and generator in series.

[0095] Preferably, such as Figures 4-5 As shown, the regenerator 4 is a spiral plate heat exchanger, which includes a first heat exchange channel 41 and a second heat exchange channel 42. The first heat exchange channel 41 is located on the outer wall of the core 1, and the second heat exchange channel 42 is stacked on the outer wall of the first heat exchange channel 41. The first heat exchange channel 41 and the second heat exchange channel 42 together form a spiral channel around the core 1.

[0096] In this embodiment, a spiral plate heat exchanger is used, which combines heat exchange with shielding of the reactor core's radial neutrons and gamma rays, thus greatly reducing the volume of the reactor system. At the same time, it includes a first heat exchange channel 41 and a second heat exchange channel 42, which can achieve efficient heat exchange while reducing the volume.

[0097] like Figures 4-5 As shown, preferably, the first heat exchange channel 41 and the second heat exchange channel 42 meet one or more of the following conditions;

[0098] Each of the first heat exchange channel 41 and the second heat exchange channel 42 is independently provided with equidistantly arranged fixed columns 43.

[0099] In this embodiment, the fixed-distance column 43 can increase the area in the channel that is in contact with the fluid, that is, increase the heat exchange area of ​​the fluid and improve the heat exchange effect.

[0100] The channel spacing between the first heat exchange channel 41 and the second heat exchange channel 42 is 10-20 mm each;

[0101] The number of windings of the first heat exchange channel 41 and the second heat exchange channel 42 is 4 layers each;

[0102] The sidewall thickness of the first heat exchange channel 41 and the second heat exchange channel 42 is 3 mm each independently;

[0103] The first heat exchange channel 41 and the second heat exchange channel 42 are made of GH3535 alloy.

[0104] Preferably, the diameter of the spacer post 43 is 10mm, and the distance between the spacer posts 43 is 25mm.

[0105] Preferably, such as Figure 6 As shown, the cooler 5 is an annular shell-and-tube heat exchanger. The interior of the annular shell-and-tube heat exchanger includes a gas pipe 51, which spirals around the regenerator 4. The shell of the annular shell-and-tube heat exchanger is installed on the regenerator 4 to form a cavity. The cavity surrounds the gas pipe 51 for the flow of coolant fluid.

[0106] In this embodiment, the cooler 5 is an annular sleeve heat exchanger, which combines heat exchange and shielding of the reactor core radial neutrons and gamma rays. It includes a gas pipe 51 for cooling the hot fluid coming out of the first heat exchange channel 41. Water is used as the cooling liquid in the coolant cavity to facilitate the removal of waste heat.

[0107] In other embodiments, other liquids may be used as the cooling liquid within the coolant chamber.

[0108] Preferably, the annular shell-and-tube heat exchanger meets one or more of the following conditions;

[0109] The diameter of the sleeve in the annular shell-and-tube heat exchanger is 30cm.

[0110] The sleeve thickness of the annular sleeve heat exchanger is 3mm;

[0111] The diameter of the gas pipeline is 25mm;

[0112] The thickness of the gas pipeline is 2.5 mm.

[0113] Preferably, the first heat exchange channel 41 is provided with a hot fluid inlet 44 at the fluid outlet end of the core 1 for communicating with the outlet of the turbine 3; the first heat exchange channel 41 is provided with a hot fluid outlet 45 at the sealed end of the core 1.

[0114] The gas pipeline inlet 52 is connected to the hot fluid outlet 45 of the first heat exchange channel 41 and is used to cool the hot fluid coming out of the first heat exchange channel 41.

[0115] The compressor 6 has an inlet at the sealed end away from the core 1, and is connected to the outlet 53 of the gas pipeline.

[0116] The second heat exchange channel 42 is provided with a cold fluid inlet 46 at the sealed end of the core 1;

[0117] The outlet of compressor 6 is located at one end near the sealed end of core 1 and is connected to the cold fluid inlet 46 of the second heat exchange channel 42.

[0118] The second heat exchange channel 42 is provided with a cold fluid outlet 47 at the fluid outlet end of the core 1;

[0119] The cold fluid outlet 47 of the second heat exchange channel 42 is connected to the fluid inlet of the core subsystem.

[0120] In this embodiment, the fluid in the core subsystem flows into the turbine 3 from the fluid outlet of the core subsystem, then flows into the hot fluid inlet 44 of the first heat exchange channel 41 from the outlet of the turbine 3, and then flows into the gas pipe inlet 52 of the cooler 5 from the hot fluid outlet 45 of the first heat exchange channel 41. It then flows into the inlet of the compressor 6 from the outlet 53 of the gas pipe, and then flows into the cold fluid inlet 46 of the second heat exchange channel 42 from the outlet of the compressor 6. Finally, it flows back to the fluid inlet of the core subsystem from the cold fluid outlet 47 of the second heat exchange channel 42, thus entering the core and completing one fluid cycle.

[0121] Preferably, the helium-xenon cooled microreactor system further includes a water-air heat exchanger 8. The cooler 5 is provided with a coolant inlet 54 at the same end as the outlet 53 of the gas pipeline and a coolant outlet 55 at the same end as the inlet 52 of the gas pipeline. The coolant inlet 54 is connected to the outlet of the water-air heat exchanger 8, and the coolant outlet 55 is connected to the inlet of the water-air heat exchanger 8.

[0122] In this embodiment, waste heat is discharged into the air through the circulation of coolant in cooler 5 and water-air heat exchanger 8.

[0123] Preferably, such as Figure 2 As shown, the reactor core subsystem, from the axis outwards, includes a rotating shaft channel 11, a core active region 12, a reflector layer 13, and a shell 14; wherein,

[0124] The core active region 12 includes a moderator matrix 17 that fills the core active region 12. The moderator matrix 17 is provided with a plurality of fuel rods 121 and a plurality of coolant pipes 122 along the axial circumferential direction.

[0125] The reflective layer 13 is provided with several control drums 131.

[0126] Preferably, the space between the reflector layer 13 and the shell 14 forms a first cavity 15, and the space between the two end faces of the shell 14 and the moderator matrix 17 forms a second cavity 16. The first cavity 15, the second cavity 16 and the coolant pipe 122 are interconnected. The shell 14 is provided with a fluid inlet end and a fluid outlet end of the core subsystem.

[0127] In this embodiment, the cold fluid outlet 47 is connected to the first cavity 15, so that the second heat exchange channel 42 is connected to the first cavity 15. The cold fluid flowing out of the second heat exchange channel 42 flows into the first cavity 15, then flows to the second cavity 16, and finally enters the coolant pipe 122 to complete the fluid circulation.

[0128] Preferably, the reactor core subsystem meets one or more of the following conditions;

[0129] The material of the moderator matrix 17 is graphite;

[0130] The diameter of the rotating shaft channel 11 is 10cm;

[0131] The sidewall thickness of the rotating shaft channel 11 is 2cm;

[0132] The sidewall material of the rotating shaft channel 11 is boron-containing polyethylene;

[0133] The diameter of the active core region 12 is 60 cm;

[0134] The length of the active region 12 in the reactor core is 50 cm;

[0135] The diameter of fuel rod 121 is 15 mm;

[0136] The fuel rod 121 is fueled by uranium carbide fuel with an enrichment of ≤20% and a density of 13.6 g / cm³. 3 ;

[0137] Preferably, such as Figure 3 As shown, each fuel rod 121 is surrounded by 6 coolant pipes 122 arranged in a hexagonal pattern; the distance between the center of the fuel rod 121 and the center of the coolant pipe 122 is 15 mm;

[0138] In this technical solution, the uniformly arranged coolant pipes 122 can efficiently remove the nuclear heat around the fuel rods 121.

[0139] The fuel enrichment of the active zone 12 in the core is divided into three zones along the axis outward, namely 5-10%, 19.75%, and 5-10% respectively.

[0140] The diameter of coolant pipe 122 is 5mm;

[0141] The thickness of coolant pipe 122 is 0.2 mm;

[0142] The sidewall material of coolant pipe 122 is SiC;

[0143] The coolant is a helium-xenon mixture; wherein, the proportion of Xe in the helium-xenon mixture is 8% to 30%, and the molecular weight of the mixture is 15 to 42 g / mol;

[0144] The number of control drums 131 is 8;

[0145] The diameter of the control drum 131 is 5.75 cm;

[0146] The control drum 131 is a cylinder. The neutron absorbing material in the control drum 131 is located on the side wall of the cylinder. The length is the length of a 60° arc along the circumference of the cylinder, the height is the height of the cylinder, and the thickness is 0.8 cm.

[0147] In this embodiment, the control drum 131 is used for the reactivity control of the reactor core 1 and the start-up and shutdown of the reactor core 1.

[0148] The neutron-absorbing material of the control drum 131 is B4C;

[0149] In this embodiment, the B4C layer in the control drum 131 can rotate freely around a circle with a diameter of 5.75. When the reactor is running, the B4C layer turns outward from the core. When the reactor is shut down in an emergency, the B4C layer turns outward to the active region 12 of the core to absorb neutrons, thereby reducing the reactivity of the core below the critical level.

[0150] The thickness of the reflective layer 13 is 20cm;

[0151] The material of reflective layer 13 is BeO;

[0152] The channel thickness of the first cavity 15 is 2cm;

[0153] Core 1 has a power output of 5MW;

[0154] The diameter and height of core 1 are 25-50 cm, which can meet the design requirements for miniaturization and miniaturization of the reactor system.

[0155] The helium-xenon cooled microreactor provided in this embodiment connects the regenerator 4 to the outer wall of the reactor core 1, and the cooler 5 to the outer wall of the regenerator 4, forming a reactor system integrating thermoelectric conversion and shielding functions. Eliminating the need for a shielding layer significantly reduces the size of the reactor system, making it miniaturized, compact, and lightweight. Furthermore, using the Monte Carlo MCNP neutron analysis software, under the same conditions, compared to a traditional Brayton cycle distributed reactor system, the neutron and gamma doses can be reduced by two orders of magnitude, and the amount of shielding material required can be reduced by one order of magnitude.

[0156] While specific embodiments of the present invention have been described above, those skilled in the art should understand that these are merely illustrative examples, and the scope of protection of the present invention is defined by the appended claims. Those skilled in the art can make various changes or modifications to these embodiments without departing from the principles and essence of the present invention, but all such changes and modifications fall within the scope of protection of the present invention.

Claims

1. A helium-xenon cooled microreactor system, characterized in that, The helium-xenon cooled microreactor system includes a core subsystem and a Brayton cycle subsystem. The core subsystem is arranged laterally and is equipped with a rotating shaft that passes through the core axis; The Brayton cycle subsystem includes a turbine, a regenerator, a cooler, and a compressor; The turbine is located at the fluid outlet end of the reactor core; the regenerator and the cooler are coaxially sleeved with the reactor core, the regenerator is sleeved with the outer wall of the reactor core, and the cooler is sleeved with the outer wall of the regenerator. The compressor is located at the sealed end opposite the fluid outlet end of the reactor core. The compressor, the reactor core, and the turbine are arranged sequentially along the axial direction of the reactor core, and the rotating shaft connects the compressor, the reactor core, and the turbine in series. The reactor core subsystem, from the axis outwards, includes, in sequence, a shaft channel, a core active region, a reflector layer, and a shell; wherein... The active core region includes a moderator matrix that fills the active core region, and the moderator matrix is ​​provided with a plurality of fuel rods and a plurality of coolant conduits along the circumferential direction of the axis. The reflective layer is provided with several control drums; The space between the reflector layer and the shell forms a first cavity, and the space between the two end faces of the shell and the moderator matrix forms a second cavity. The first cavity, the second cavity, and the coolant pipe are interconnected. The shell is provided with a fluid inlet end and a fluid outlet end of the reactor core subsystem.

2. The helium-xenon cooled microreactor system as described in claim 1, characterized in that, The regenerator is a spiral plate heat exchanger, which includes a first heat exchange channel and a second heat exchange channel. The first heat exchange channel is located on the outer wall of the core, and the second heat exchange channel is stacked on the outer wall of the first heat exchange channel. The first heat exchange channel and the second heat exchange channel together form a spiral channel around the core. And / or, the Brayton cycle subsystem further includes a motor, and the turbine is also connected to the motor via the shaft along the axial direction of the reactor core.

3. The helium-xenon cooled microreactor system as described in claim 2, characterized in that, The first heat exchange channel and the second heat exchange channel meet one or more of the following conditions; The first heat exchange channel and the second heat exchange channel are each independently provided with equidistantly arranged fixed-distance columns. The channel spacing between the first heat exchange channel and the second heat exchange channel is 10~20 mm each independently; The number of windings of the first heat exchange channel and the second heat exchange channel are each 4 to 10 layers independently; The sidewall thickness of the first heat exchange channel and the second heat exchange channel is 3 mm each independently; The first and second heat exchange channels are made of GH3535 alloy.

4. The helium-xenon cooled microreactor system as described in claim 3, characterized in that, The first heat exchange channel and the second heat exchange channel each have 4 layers of windings.

5. The helium-xenon cooled microreactor system as described in claim 3 or 4, characterized in that, The diameter of the fixed-distance column is 10 mm, and the distance between the fixed-distance columns is 25 mm.

6. The helium-xenon cooled microreactor system as described in claim 2, characterized in that, The cooler is an annular shell-and-tube heat exchanger. The interior of the annular shell-and-tube heat exchanger includes a gas pipe that spirals around the regenerator. The shell of the annular shell-and-tube heat exchanger is fitted onto the regenerator to form a cavity. The cavity surrounds the gas pipe and is used for the flow of coolant fluid.

7. The helium-xenon cooled microreactor system as described in claim 6, characterized in that, The annular sleeve heat exchanger meets one or more of the following conditions; The diameter of the sleeve in the annular sleeve heat exchanger is 10cm-30cm; The sleeve thickness of the annular sleeve heat exchanger is 2-5 mm; The diameter of the gas pipeline is 20-30 mm; The thickness of the gas pipeline is 2.5 mm.

8. The helium-xenon cooled microreactor system as described in claim 7, characterized in that, The diameter of the sleeve of the annular sleeve heat exchanger is 30cm.

9. The helium-xenon cooled microreactor system as described in claim 7, characterized in that, The sleeve thickness of the annular sleeve heat exchanger is 3mm.

10. The helium-xenon cooled microreactor system as described in claim 7, characterized in that, The diameter of the gas pipe is 25 mm.

11. The helium-xenon cooled microreactor system as described in any one of claims 6-10, characterized in that, The first heat exchange channel has a hot fluid inlet at the fluid outlet end of the reactor core for communicating with the turbine outlet; the first heat exchange channel has a hot fluid outlet at the sealed end of the reactor core. The inlet of the gas pipe is connected to the hot fluid outlet of the first heat exchange channel, and is used to cool the hot fluid coming out of the first heat exchange channel. The compressor has an inlet at the sealed end away from the core, and is connected to the outlet of the gas pipeline; The second heat exchange channel is provided with a cold fluid inlet at the sealed end of the reactor core; The compressor outlet is located at one end near the sealed end of the core and is connected to the cold fluid inlet of the second heat exchange channel. The second heat exchange channel is provided with a cold fluid outlet at the fluid outlet end of the reactor core; The cold fluid outlet of the second heat exchange channel is connected to the fluid inlet of the core subsystem.

12. The helium-xenon cooled microreactor system as described in claim 1, characterized in that, The core subsystem meets one or more of the following conditions; The material of the modifier matrix is ​​graphite; The diameter of the rotating shaft channel is 5cm-10cm; The sidewall thickness of the rotating shaft channel is 2cm-5cm; The sidewall material of the rotating shaft channel is boron-containing polyethylene; The diameter of the active region in the reactor core is 50-80 cm; The length of the active region in the reactor core is 40-60 cm; The diameter of the fuel rod is 10~20 mm; The fuel rods are fueled by uranium carbide fuel with an enrichment of ≤20%; The fuel enrichment of the active region of the reactor core is divided into three zones along the axis outward, namely 5-10%, 19.75%, and 5-10% respectively. The diameter of the coolant pipe is 4~10 mm; The thickness of the coolant pipe is 0.2~0.5 mm; The sidewall material of the coolant pipe is SiC; The coolant is a helium-xenon mixture; The number of control drums is 8; The diameter of the control drum is 5-7 cm; The control drum is a cylinder, and the neutron absorbing material in the control drum is disposed on the side wall of the cylinder. The length is the length of a 60° arc along the circumference of the cylinder, the height is the height of the cylinder, and the thickness is 0.6-1.2 cm. The neutron-absorbing material of the control drum is B4C; The thickness of the reflective layer is 15-30 cm; The material of the reflective layer is BeO; The thickness of the channel in the first cavity is 1.5-3 cm; The core consolidation rate is 1~5 MW; The diameter and height of the reactor core are 25-50 cm.

13. The helium-xenon cooled microreactor system as described in claim 12, characterized in that, The diameter of the rotating shaft channel is 10cm.

14. The helium-xenon cooled microreactor system as described in claim 12, characterized in that, The sidewall thickness of the rotating shaft channel is 2cm.

15. The helium-xenon cooled microreactor system as described in claim 12, characterized in that, The diameter of the active region in the reactor core is 60 cm.

16. The helium-xenon cooled microreactor system as described in claim 12, characterized in that, The length of the active region in the reactor core is 50 cm.

17. The helium-xenon cooled microreactor system as described in claim 12, characterized in that, The fuel rod has a diameter of 15 mm.

18. The helium-xenon cooled microreactor system as described in claim 12, characterized in that, The density of the uranium carbide fuel is 13.6 g / cm3.

19. The helium-xenon cooled microreactor system as described in claim 12, characterized in that, Each fuel rod is surrounded by six coolant pipes arranged in a hexagonal pattern; the distance between the center of the fuel rod and the center of the coolant pipe is 13-17 mm.

20. The helium-xenon cooled microreactor system as described in claim 19, characterized in that, The distance between the center of the fuel rod and the center of the coolant pipe is 15 mm.

21. The helium-xenon cooled microreactor system as described in claim 12, characterized in that, The diameter of the coolant pipe is 5 mm.

22. The helium-xenon cooled microreactor system as described in claim 12, characterized in that, The thickness of the coolant pipe is 0.2 mm.

23. The helium-xenon cooled microreactor system as described in claim 12, characterized in that, The proportion of Xe in the helium-xenon mixture is 8% to 30%, and the molecular weight of the mixture is 15 to 42 g / mol.

24. The helium-xenon cooled microreactor system as described in claim 12, characterized in that, The diameter of the control drum is 5.75 cm.

25. The helium-xenon cooled microreactor system as described in claim 12, characterized in that, The thickness of the neutron-absorbing material in the control drum is 0.8 cm.

26. The helium-xenon cooled microreactor system as described in claim 12, characterized in that, The thickness of the reflective layer is 20cm.

27. The helium-xenon cooled microreactor system as described in claim 12, characterized in that, The thickness of the channel in the first cavity is 2 cm.

28. The helium-xenon cooled microreactor system as described in claim 12, characterized in that, The core has a consolidation rate of 5 MW.

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