Sodium-cooled reactor system

Abstract

An embodiment of the present invention discloses a sodium-cooled reactor system. The sodium-cooled reactor system includes: multiple reactors, each reactor including a reactor vessel, a reactor core, and a sodium coolant. The sodium coolant is contained within the reactor vessel, and the reactor core is disposed within the reactor vessel. The sodium coolant is used to absorb heat from the reactor core; a sodium pipeline, connected between the reactor vessels of the multiple reactors, used to connect the reactor vessels of the multiple reactors in series to form a sodium circulation loop, and the sodium coolant circulates through the reactor vessels of the multiple reactors and the sodium pipeline; a heat exchange device connected to the sodium pipeline to cool the sodium coolant after absorbing heat from the reactor core; and a sodium drive device connected to the sodium pipeline to drive the sodium coolant to circulate in the sodium circulation loop. The sodium-cooled reactor system in the embodiment of the present invention breaks away from the traditional single-core design and operates multiple reactor cores in series. The multiple cores share a sodium circuit system, thereby improving the thermal efficiency of the reactor system.

Description

Technical Field

[0001] The embodiments of the present invention relate to the technical field of nuclear reactors, and in particular to a sodium-cooled reactor system. Background Art

[0002] Large-scale sodium-cooled fast reactors (SFRs) often adopt a pool-type design. Their reactor vessels contain large quantities of sodium coolant, resulting in a very high sodium loading and power ratio. However, these reactors have long construction cycles and high costs, and their systems lack flexibility for maintenance and modification. For example, if equipment within the reactor pool fails and requires repair, the entire unit must be shut down. Furthermore, if critical equipment suffers irreparable damage, the entire unit can be scrapped, severely impacting the economic viability of the power plant. To address this issue, research on small SFRs has been conducted. Small SFRs, with their smaller system equipment and greater suitability for underground deployment, offer advantages such as increased safety, feasible design and construction techniques, and reasonable costs.

[0003] However, the temperature of the primary circuit system (ie, the sodium coolant circuit) of the current small sodium-cooled fast reactor is only about 300-320° C., and the thermal efficiency of power generation is only about 20-30%, resulting in poor economic efficiency. Summary of the Invention

[0004] According to one embodiment of the present invention, a sodium-cooled reactor system is provided. The sodium-cooled reactor system includes: multiple reactors, each reactor including a reactor vessel, a reactor core, and a sodium coolant. The sodium coolant is contained within the reactor vessel, and the reactor core is disposed within the reactor vessel. The sodium coolant is used to absorb heat from the reactor core. A sodium pipeline is connected between the reactor vessels of the multiple reactors and is used to connect the reactor vessels of the multiple reactors in series to form a sodium circulation loop. The sodium coolant circulates through the reactor vessels of the multiple reactors and the sodium pipeline. A heat exchange device is connected to the sodium pipeline and is used to cool the sodium coolant after absorbing heat from the reactor core. A sodium drive device is connected to the sodium pipeline and is used to drive the sodium coolant to circulate in the sodium circulation loop.

[0005] The sodium-cooled reactor system in the embodiment of the present invention breaks away from the traditional single-core design and operates multiple reactor cores in series. Multiple cores share a sodium loop system, which is more conducive to core cooling control, reduces the temperature rise of a single core, significantly increases the temperature of the sodium coolant in the heat exchange device in the sodium loop, and improves the thermal efficiency of the reactor system. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Other objects and advantages of the present invention will become apparent from the following description of the embodiments of the present invention with reference to the accompanying drawings, which will help to provide a comprehensive understanding of the present invention.

[0007] Figure 1 1 is a schematic structural diagram of a sodium-cooled reactor system according to an embodiment of the present invention.

[0008] Figure 2 1 is a schematic structural diagram of a sodium-cooled reactor system according to another embodiment of the present invention.

[0009] Figure 3 Schematic diagram of the structure of a reactor according to one embodiment of the present invention.

[0010] Figure 4 Schematic diagram of the structure of a sodium process room according to one embodiment of the present invention.

[0011] It should be noted that the drawings are not necessarily drawn to scale, but are merely shown in a schematic manner that does not affect the reader's understanding. DETAILED DESCRIPTION

[0012] To make the purpose, technical solutions, and advantages of this application more clear, the technical solutions of this application will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of this application. Obviously, the described embodiment is only one embodiment of this application, not all embodiments. Based on the described embodiments of this application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0013] It should be noted that, unless otherwise defined, the technical or scientific terms used in this application should have the usual meanings understood by persons of ordinary skill in the field to which this application belongs. If the full text involves descriptions such as "first" and "second", the "first" and "second" descriptions are only used to distinguish similar objects and should not be understood as indicating or implying their relative importance, order of precedence, or implicitly indicating the number of technical features indicated. It should be understood that the data described by "first" and "second" are interchangeable under appropriate circumstances. If "and / or" appears in the full text, its meaning includes three parallel solutions. Taking "A and / or B" as an example, it includes Solution A, Solution B, or solutions in which both A and B are satisfied. In addition, for ease of description, spatial relative terms such as "above", "below", "top", "bottom", etc. may be used here to describe the spatial positional relationship between a device or feature as shown in the figure and other devices or features, and should be understood to also include different orientations in use or operation other than the orientation shown in the figure.

[0014] Sodium-cooled fast reactors (SFRs) are fast neutron spectrum reactors that use liquid metallic sodium as the reactor coolant. Traditional SFR systems utilize a single core design, resulting in a large core temperature rise and low sodium temperature at the core outlet. This results in low thermal efficiency and poor economic efficiency.

[0015] An embodiment of the present invention provides a sodium-cooled reactor system. Figure 1A schematic structural diagram of a sodium-cooled reactor system according to an embodiment of the present invention is shown. Figure 2 A schematic structural diagram of a sodium-cooled reactor system according to another embodiment of the present invention is shown.

[0016] like Figure 1 and Figure 2 As shown, the sodium-cooled reactor system in an embodiment of the present invention includes multiple reactors 100, a sodium pipeline 210, a heat exchange device 220, and a sodium drive device 230. The reactor 100 includes a core 110, a reactor vessel 120, and a sodium coolant. The sodium coolant is contained within the reactor vessel 120, and the core 110 is disposed within the reactor vessel 120. The sodium coolant is used to absorb heat from the core 110. The sodium pipeline 210 is connected between the reactor vessels 120 of the multiple reactors 100, connecting the reactor vessels 120 in series to form a sodium circulation loop. The sodium coolant circulates through the reactor vessels 120 and the sodium pipeline 210 of the multiple reactors 100. The heat exchange device 220 is connected to the sodium pipeline 210 to cool the sodium coolant after absorbing heat from the core 110. The sodium drive device 230 is connected to the sodium pipeline 210 to drive the sodium coolant to circulate within the sodium circulation loop.

[0017] In this embodiment, the reactor is a small loop-type sodium-cooled fast reactor, and multiple small loop-type sodium-cooled fast reactors are connected in series and share a single sodium circulation loop. The sodium-cooled reactor system in this embodiment breaks away from the traditional single-core design. By utilizing the small temperature difference between the inlet and outlet of the sodium coolant of a single small reactor, the cores 110 of multiple small reactors are operated in series. Multiple cores 110 share a single sodium circulation loop, which is more conducive to cooling control of the cores 110, improves the safety of the reactor system, and reduces the temperature rise of a single core 110, which is beneficial to the safety and long-term use of the reactor system. It also significantly increases the temperature of the sodium coolant in the heat exchange device 220 in the sodium loop, thereby improving the thermal efficiency of the reactor system.

[0018] As Figure 1 and Figure 2 Taking the four reactors 100 connected in series as an example, the sodium temperature at the inlet of the first-stage reactor core 110 is designed to be 330°C. The temperature rise of a single core 110 is 80°C, and the sodium temperature at the outlet of the fourth-stage reactor core 110 is designed to be 650°C. Compared to conventional single-core sodium-cooled fast reactors, which have a core inlet sodium temperature of 358°C and an outlet sodium temperature of 540°C, the reactor system in this embodiment reduces the temperature rise of a single core while increasing the final core outlet temperature, thereby improving the thermal efficiency of the reactor system.

[0019] In this embodiment, reactor 100 uses liquid metallic sodium as a coolant. Sodium has high thermal conductivity and a high boiling point, allowing for low-pressure operation. Furthermore, sodium has a low neutron absorption cross-section, effectively dissipating heat from reactor core 110. In some embodiments, uranium dioxide is used as the fuel in core 110.

[0020] In some embodiments, the reactor 100 further includes a passive shutdown module for safely shutting down the reactor 100 in the event of an abnormal or accidental operating condition. In this embodiment, the passive shutdown module includes control rods, a control rod drive, and an electromagnet. The electromagnet is connected between the control rods and the control rod drive, thereby achieving a connection between the control rods and the control rod drive. In this embodiment, the electromagnet has a Curie point temperature, i.e., a magnetic transition temperature.

[0021] During normal operation of the reactor 100, the control rod drive mechanism drives the control rods relative to the core 110. When inserted into the core 110, the control rods absorb neutrons, controlling the rate of the fuel fission reaction in the core 110 and thereby controlling the power of the reactor 100. During an abnormal or accidental operation of the reactor 100, the temperature within the reactor 100 rises. When the temperature reaches the Curie point, the magnetism of the electromagnet decreases, causing the control rods to disengage from the control rod drive mechanism and fall into the core 110, shutting down the reactor 100. After the shutdown, the reactor 100 gradually cools, preventing accidents and ensuring the safety of the reactor 100.

[0022] In some embodiments, the reactor 100 further includes a passive residual heat removal module for removing residual heat from the reactor core 110 when heat within the reactor 100 cannot be normally removed through the sodium circulation loop. Specifically, the residual heat removal module includes a residual heat removal heat exchanger and a cooling water tank. Cooling water circulates between the cooling water tank and the residual heat removal heat exchanger, and sodium coolant circulates between the residual heat removal heat exchanger and the reactor vessel 120.

[0023] During normal operation of the reactor 100, the residual heat removal module is in a standby state. The temperature of the sodium coolant in the residual heat removal heat exchanger is equivalent to the temperature of the cooling water in the cooling water tank, and the pressure of the sodium coolant in the residual heat removal heat exchanger is consistent with the pressure of the sodium coolant in the reactor vessel 120 of the reactor 100. During abnormal or accident conditions of the reactor 100, the residual heat removal module is in an operational state. The sodium coolant in the residual heat removal heat exchanger has a lower temperature and a higher density due to cooling by the cooling water. The sodium coolant in the reactor vessel 120 has a higher temperature and a lower density due to the inability to be cooled normally through the sodium circulation loop. Due to the pressure difference, the sodium coolant in the residual heat removal heat exchanger and the reactor vessel 120 flows in a natural circulation manner, thereby removing heat from the core 110.

[0024] In an embodiment of the present invention, a passive residual heat removal module is provided in the reactor 100. The pressure difference formed by the density difference between the cold and hot working fluids in the residual heat removal module provides driving force, and the residual heat of the reactor 100 is removed by natural circulation to ensure the safety of the reactor 100.

[0025] like Figure 1 and 2 As shown, in some embodiments, the sodium-cooled reactor system further includes a plurality of sodium coolant branches 240, each of which is correspondingly disposed outside each reactor 100 and connected in parallel to the reactor vessel 120 of the reactor 100. By controlling the on / off of each sodium coolant branch 240, a different number of reactors 100 can be selected for series connection.

[0026] This embodiment employs a bypass single-stack design for multiple reactors 100 connected in series. While one reactor 100 undergoes refueling and maintenance, the other reactors 100 can continue to operate. This embodiment utilizes a loop-type small core design and a bypassable single-stack design, allowing for the replacement of the core vessel and auxiliary system equipment. This avoids the need for complete unit shutdown for equipment damage and maintenance in traditional single-core reactors, thus facilitating the safety and long-term operation of the reactor system. Furthermore, this embodiment incorporates redundant cooling capacity within the sodium circulation loop, ensuring cooling of each core even in the event of a single loop leak or loss of flow.

[0027] In some embodiments, each reactor 100 can be arranged underground. Underground nuclear power plants have obvious advantages in containing radioactive materials under severe accident conditions, can simplify off-site emergency plans, and have the technical possibility of eliminating off-site emergency response areas.

[0028] Furthermore, the multiple reactors 100 can be separately arranged in different underground spaces, thereby isolating the multiple reactors 100 and preventing a sodium leakage accident in a single reactor 100 from affecting the operational safety of other reactors 100 .

[0029] Figure 3 FIG. 1 shows a schematic structural diagram of a reactor according to an embodiment of the present invention. Figure 3 As shown, the reactor 100 in this embodiment further includes an outlet pipe 250 and at least one control valve 260. The outlet pipe 250 is disposed on the reactor vessel 120 and is used to connect the reactor vessel 120 of the reactor 100 with the sodium pipeline 210 outside the reactor 100. At least one control valve 260 is disposed on the outlet pipe 250 and is used to control the flow of sodium coolant in the outlet pipe 250.

[0030] In this embodiment, an outlet pipe 250 is provided to lead the sodium coolant in the reactor vessel 120 to the sodium pipeline 210. At the same time, a control valve 260 provided on the outlet pipe 250 is used to control the opening and closing of the outlet pipe 250. Therefore, when a reactor 100 is undergoing refueling maintenance, the circulation of the sodium coolant of the reactor 100 can be stopped, allowing the other reactors 100 to operate normally.

[0031] In some embodiments, the reactor vessel 120 of the reactor 100 contains sodium coolant, and the core 110 is disposed in the sodium coolant. Two outlet pipes 250 are provided on the reactor vessel 120. Both outlet pipes 250 are connected to the sodium coolant in the reactor vessel 120, thereby facilitating the withdrawal of the sodium coolant from the reactor vessel 120. Furthermore, the two outlet pipes 250 are disposed at the height of the bottom and top of the core 110, respectively. In this embodiment, sodium coolant enters the core 110 from the bottom of the core 110 and absorbs heat from the core 110 to cool the core 110; the heated sodium coolant flows out from the top of the core 110, is transported to the sodium pipeline 210 outside the reactor 100 through the outlet pipe 250 at the top of the core 110, and is cooled in the heat exchanger; the cooled sodium coolant is transported to the bottom of the core 110 in the reactor vessel 120 through another outlet pipe 250, thereby realizing the circulation of the sodium coolant.

[0032] In some embodiments, there are two control valves 260, which are connected in series to the outlet pipe 250 to better seal the sodium coolant within the stack container 120 when the control valves 260 are closed. For example, a first control valve 260 and a second control valve 260 are connected in series to the outlet pipe 250, with the first control valve 260 being closer to the stack container 120 than the second control valve 260. In some embodiments, the control valves 260 are shut-off valves.

[0033] In some embodiments, the sodium pipeline 210 and the outlet pipe 250 are seamless stainless steel pipes, connected by welding to minimize sodium leakage. In some embodiments, at least a portion of the walls of the outlet pipe 250 and the sodium pipeline 210 are double-walled to minimize sodium leakage. For example, the wall of the portion of the outlet pipe 250 between the first control valve 260 and the nozzle in the stack container 120 can be double-walled.

[0034] In some embodiments, a siphon breaker device 270 is provided at the outlet of the outlet pipe 250 located within the reactor vessel 120 to limit leakage of sodium coolant within the reactor vessel 120. When the sodium pipeline 210 outside the reactor 100 ruptures or breaks, the sodium coolant within the reactor vessel 120 will leak out of the reactor vessel 100 through the ruptured sodium pipeline 210 via a siphon effect. In this embodiment, the siphon breaker device 270 is provided at the outlet of the outlet pipe 250 to break the siphon effect, thereby stopping the discharge of sodium coolant from the reactor vessel 120 to the outside of the reactor vessel 120 and limiting the amount of sodium coolant leakage from the reactor vessel 120.

[0035] In some embodiments, the sodium-cooled reactor system further includes at least one sodium process room 400, in which the sodium pipeline 210 is disposed. The sodium process room 400 is filled with an inert gas. It should be noted that the sodium process room 400 in the embodiments of the present invention refers to a room or location through which the sodium pipeline 210 passes and where sodium leakage may occur. In some embodiments, the inert gas is nitrogen.

[0036] In this embodiment, the sodium-cooled reactor system can be set up underground. Taking advantage of the fact that underground space is conducive to the construction of an inert gas environment, the sodium process room 400 is set up underground. By flooding with nitrogen, a low-oxygen or oxygen-free environment is constructed in the underground sodium process room 400 to strictly control the cleanliness of the sodium process room 400, avoid sodium combustion accidents when sodium leaks, and ensure the safety of the sodium-cooled reactor system.

[0037] In some embodiments, the sodium-cooled reactor system further includes an alarm module, which is partially disposed in the sodium process room 400 and is configured to sound an alarm when sodium combustion occurs in the sodium process room 400, so as to remind operators to take timely sodium fire emergency measures.

[0038] In some embodiments, the alarm module includes a gas detection device 510, an alarm device and an alarm control device. Figure 4 As shown, a gas detection device 510 is installed in the sodium processing room 400 to detect the gas composition within the sodium processing room 400. An alarm device is used to generate an alarm. For example, the alarm device can generate an alarm using at least one of an acoustic, optical, or electrical signal. An alarm control device is connected to the gas detection device 510 and the alarm device, respectively, to receive detection signals from the gas detection device 510 and control the alarm device based on the detection signals.

[0039] In this embodiment, the gas detection device 510 can detect the gas composition in the sodium process room 400 in real time, and the detection signal of the gas detection device 510 can be transmitted to the alarm control device in real time as an input signal of the alarm control device. The alarm control device determines whether a sodium fire accident has occurred in the sodium process room 400 based on the detection signal. Specifically, when the detection signal of the gas detection device 510 indicates that the gas composition in the sodium process room 400 is abnormal, or indicates that the sodium process room 400 contains other components with a high concentration other than inert gas (for example, nitrogen), the alarm control device sends an alarm signal to the alarm device to control the alarm device to issue an alarm prompt, so that emergency measures can be taken in time when a sodium fire occurs to avoid a safety accident.

[0040] like Figure 4 As shown, in some embodiments, the sodium process room 400 is provided with a smoke exhaust device 600, which is used to discharge smoke when a sodium combustion accident occurs in the sodium process room 400, to ensure that the combustion products in the sodium process room 400 can be discharged in time after a fire occurs, and to prevent the radioactive sodium aerosol generated by the sodium combustion from spreading to adjacent process rooms.

[0041] In some embodiments, the smoke exhaust device 600 includes a smoke exhaust duct 610, a smoke exhaust fan 620, and at least one filter 630. The smoke exhaust duct 610 is partially disposed within the sodium process room 400 and communicates with the exterior of the sodium process room 400. The smoke exhaust fan 620 is disposed on the smoke exhaust duct 610 to draw smoke from the sodium process room 400 into the smoke exhaust duct 610. The filter 630 is disposed on the smoke exhaust duct 610 to filter sodium aerosols from the gas. The smoke exhaust duct 610 is used to discharge the filtered smoke.

[0042] In this embodiment, at least one filter 630 is provided on the smoke exhaust duct 610 to filter the sodium aerosol generated by sodium combustion, and the sodium combustion products are discharged into the filter 630 for purification before being discharged externally, thereby preventing the sodium aerosol from being discharged to the outside and causing pollution.

[0043] The embodiment of the present invention utilizes the underground sodium process room 400 to establish an inert gas environment, which greatly reduces the design of the sodium leakage and sodium fire protection system and improves the economy of the protection system design.

[0044] like Figure 1 and Figure 2 As shown, in some embodiments, a supercritical carbon dioxide power generation module 300 is further included, and carbon dioxide circulates within the supercritical carbon dioxide power generation module 300. The heat exchange device 220 is connected to the supercritical carbon dioxide power generation module 300 and is used to transfer heat from the sodium coolant to the carbon dioxide.

[0045] In some embodiments, a hot fluid cavity and a cold fluid cavity are formed in the heat exchange device 220 , the sodium coolant flows in the hot fluid cavity, and the carbon dioxide flows in the cold fluid cavity, thereby achieving heat transfer between the sodium coolant and the carbon dioxide in the heat exchange device 220 .

[0046] In an embodiment of the present invention, a secondary sodium-supercritical carbon dioxide loop is used to replace the sodium-sodium-water triple loop in the conventional reactor 100 system. A heat exchange device 220 for heat exchange between Na and CO2 is used between the two loops to directly transfer heat from the sodium circulation loop to the CO2 in the secondary loop, thereby avoiding the sodium-water reaction and increasing the hot end temperature of the power cycle.

[0047] In some embodiments, supercritical carbon dioxide power generation module 300 includes a turbine device 310 and a power generation device 320. Turbine device 310 is connected to heat exchange device 220, and carbon dioxide circulates between turbine device 310 and heat exchange device 220. Turbine device 310 is used to convert the thermal energy of carbon dioxide into mechanical energy. Power generation device 320 is connected to turbine device 310 to convert the mechanical energy into electrical energy, thereby achieving power generation in the sodium-cooled reactor system.

[0048] like Figure 1 As shown, in some embodiments, the supercritical carbon dioxide power generation module 300 further includes a first compression device 350, a first heat recovery device 330, and a cooling device 340. The first compression device 350 is connected between the turbine device 310 and the heat exchange device 220, and is used to compress the carbon dioxide discharged from the turbine device 310. The compressed carbon dioxide is transported to the heat exchange device 220 to absorb heat from the sodium coolant. The first heat recovery device 330 is connected between the turbine device 310 and the first compression device 350. The heat recovery device is used to cool the carbon dioxide discharged from the turbine device 310. The cooled carbon dioxide is transported to the first compression device 350. The cooling device 340 is connected between the first heat recovery device 330 and the first compression device 350, and is used to cool the carbon dioxide.

[0049] In this embodiment, the carbon dioxide exhausted from the turbine unit 310 flows sequentially through the first reheating unit 330, the cooling unit 340, and the first compression unit 350 for cooling and compression. Cooling the carbon dioxide exhausted from the turbine unit 310 before compression can prevent the inlet temperature of the first compression unit 350 from being too high.

[0050] like Figure 1As shown, the first reheat device 330 is also connected between the first compression device 350 and the heat exchange device 220. The first reheat device 330 is used to transfer the waste heat of the carbon dioxide discharged from the turbine device 310 to the carbon dioxide compressed by the first compression device 350. The carbon dioxide discharged from the turbine device 310 flows sequentially through the first reheat device 330, the cooling device 340, and the first compression device 350 for cooling and compression. The carbon dioxide compressed by the first compression device 350 flows sequentially through the first reheat device 330 and the heat exchange device 220 for heating. The compressed and heated carbon dioxide then flows back into the turbine device 310.

[0051] In some embodiments, cooling device 340 may be a heat exchanger, with carbon dioxide and a cooling fluid flowing through a hot fluid chamber and a cold fluid chamber of cooling device 340, respectively, to cool the carbon dioxide using the cooling fluid. In this embodiment, cooling device 340 cools the carbon dioxide, thereby creating a temperature difference between the compressed carbon dioxide and the carbon dioxide discharged from turbine device 310. This facilitates heat recovery of the compressed carbon dioxide by first regenerator 330 using the carbon dioxide discharged from turbine device 310.

[0052] In addition, the first heat recovery device 330 is a heat exchanger having a hot fluid chamber (ie, hot end) and a cold fluid chamber (ie, cold end), in which hot fluid and cold fluid flow respectively.

[0053] In this embodiment, the outlet of the turbine device 310 is connected to the hot end inlet of the first heat recovery device 330, the hot end outlet of the first heat recovery device 330 is connected to the inlet of the cooling device 340, the outlet of the cooling device 340 is connected to the inlet of the first compression device 350, the outlet of the first compression device 350 is connected to the cold end inlet of the first heat recovery device 330, and the cold end outlet of the first heat recovery device 330 is connected to the carbon dioxide inlet of the heat exchange device 220.

[0054] The carbon dioxide exhausted from the turbine unit 310 first enters the hot fluid chamber of the first regenerator 330, then enters the cooling unit 340 for cooling, and then enters the first compression unit 350 for compression, thereby increasing the pressure of the carbon dioxide. The compressed carbon dioxide then enters the cold fluid chamber of the first regenerator 330 for heating. The waste heat of the carbon dioxide exhausted from the turbine unit 310 is used to heat the compressed carbon dioxide. This not only increases the temperature of the compressed carbon dioxide but also fully utilizes the waste heat of the carbon dioxide itself, improving the utilization rate of thermal energy and the thermal efficiency of the reactor 100 system.

[0055] In this embodiment, the carbon dioxide discharged from the turbine unit 310 is compressed and heated by the first compression device 350 and the heat exchange device 220 to maintain the carbon dioxide in a supercritical state, thereby achieving carbon dioxide recycling. It should be noted that supercritical carbon dioxide in this embodiment of the present invention refers to carbon dioxide having a temperature above the critical temperature and a pressure above the critical pressure.

[0056] In some embodiments, the supercritical carbon dioxide power generation module 300 can use a recompression Brayton cycle to generate electricity. Figure 2 As shown, the supercritical carbon dioxide power generation module 300 further includes a second heat recovery device 360. The second heat recovery device 360 ​​is connected between the turbine device 310 and the first heat recovery device 330 and is used to cool the carbon dioxide exhausted by the turbine device 310. The second heat recovery device 360 ​​is also connected between the first heat recovery device 330 and the heat exchange device 220 and is used to transfer the waste heat of the carbon dioxide exhausted by the turbine device 310 to the compressed carbon dioxide.

[0057] In this embodiment, the carbon dioxide discharged from the turbine device 310 flows through the second heat recovery device 360, the first heat recovery device 330 and the first compression device 350 in sequence for cooling and compression, and then flows into the first heat recovery device 330, the second heat recovery device 360 ​​and the heat exchange device 220 again for heating, thereby ensuring that the carbon dioxide in the supercritical carbon dioxide power generation module 300 maintains a supercritical state.

[0058] In some embodiments, the second heat recovery device 360 ​​is a heat exchanger, and the second heat recovery device 360 ​​has a hot fluid cavity (i.e., hot end) and a cold fluid cavity (i.e., cold end), and the hot fluid and the cold fluid flow in the hot fluid cavity and the cold fluid cavity of the second heat recovery device 360 ​​respectively.

[0059] In this embodiment, the outlet of the turbine device 310 is connected to the hot end inlet of the second heat recovery device 360, the hot end outlet of the second heat recovery device 360 ​​is connected to the hot end inlet of the first heat recovery device 330, the hot end outlet of the first heat recovery device 330 is connected to the inlet of the cooling device 340, the outlet of the cooling device 340 is connected to the inlet of the first compression device 350, the outlet of the first compression device 350 is connected to the cold end inlet of the first heat recovery device 330, the cold end outlet of the first heat recovery device 330 is connected to the cold end inlet of the second heat recovery device 360, and the cold end outlet of the second heat recovery device 360 ​​is connected to the carbon dioxide inlet of the heat exchange device 220.

[0060] Specifically, the carbon dioxide exhausted from the turbine unit 310 first enters the second reheat unit 360 and the first reheat unit 330 in sequence to release heat, then enters the cooling unit 340 for cooling, and then enters the first compression unit 350 for compression, thereby increasing the pressure of the carbon dioxide. The compressed carbon dioxide then enters the first reheat unit 330 and the second reheat unit 360 in sequence again for heating, using the waste heat of the carbon dioxide exhausted from the turbine unit 310 to heat the compressed carbon dioxide.

[0061] In this embodiment, by providing a second heat recovery device 360, the heat exchange efficiency between the carbon dioxide discharged from the turbine device 310 and the compressed carbon dioxide can be improved, ensuring that the sodium-cooled reactor system maintains high efficiency during changes in power demand, thereby improving the thermal efficiency of the reactor 100 system.

[0062] like Figure 2 As shown, in some embodiments, the supercritical carbon dioxide power generation module 300 further includes a second compression device 370, which is connected between the first reheat device 330 and the second reheat device 360 ​​and is used to compress a portion of the carbon dioxide cooled by the first reheat device 330. The carbon dioxide compressed by the second compression device 370 is transported to the second reheat device 360 ​​for heating. The first compression device 350 is used to compress another portion of the carbon dioxide cooled by the first reheat device 330.

[0063] In this embodiment, the carbon dioxide exhausted from the turbine unit 310 sequentially enters the second regenerator 360 and the first regenerator 330 for heat release. Part of the carbon dioxide cooled by the first regenerator 330 first enters the cooling unit 340 for cooling before entering the first compression unit 350 for compression. Another portion of the carbon dioxide cooled by the first regenerator 330 enters the second compression unit 370 for compression. By providing two compression units and a regenerator, this embodiment enhances the carbon dioxide circulation efficiency and improves the thermoelectric efficiency of the entire reactor 100 system.

[0064] In some embodiments, the inlet of the second compression device 370 is connected to the hot end outlet of the first regenerative device 330, and the outlet of the second compression device 370 is connected to the cold end inlet of the second regenerative device 360. Figure 2 As shown, a diversion point A is provided at the hot end outlet of the first heat regeneration device 330. The carbon dioxide flowing out of the first heat regeneration device 330 is diverted at the diversion point A, with a portion flowing into the cooling device 340 for cooling and then flowing into the first compression device 350 for compression, while the other portion flows into the second compression device 370 for compression.

[0065] At the same time, if Figure 2As shown, a confluence point B is provided at the cold-end entrance of the second reheating device 360. The carbon dioxide compressed by the first compression device 350 enters the first reheating device 330 for reheating, bringing its temperature to the same as that of the carbon dioxide compressed by the second compression device 370. The carbon dioxide reheated by the first reheating device 330 and the carbon dioxide compressed by the second compression device 370 are mixed at the confluence point B, and the mixed carbon dioxide flows into the second reheating device 360 ​​for reheating.

[0066] In the supercritical carbon dioxide power generation module 300 of this embodiment, the carbon dioxide exhausted from the turbine unit 310 is cooled sequentially through the second reheating device 360 ​​and the first reheating device 330. A portion of the carbon dioxide then flows directly into the second compression device 370 for compression. The remaining portion of the carbon dioxide is first cooled by the cooling device 340 before entering the first compression device 350 for compression and then reheating through the first reheating device 330. The carbon dioxide reheated in the first reheating device 330 is mixed with the carbon dioxide compressed in the second compression device 370. The carbon dioxide then flows sequentially into the second reheating device 360 ​​and the heat exchange device 220 for heating, resulting in high-temperature, high-pressure carbon dioxide that flows into the turbine unit 310 to perform work, thus forming a closed power generation cycle.

[0067] As Figure 2 Taking the sodium-cooled reactor system shown as an example, with the sodium coolant branch 240 of the reactor system not in operation, four reactors 100 are connected in series. The sodium temperature at the inlet of the first-stage reactor core 110 is designed to be 330°C, with a temperature rise of 80°C for each core 110. The sodium temperature at the outlet of the fourth-stage reactor core 110 is designed to be 650°C. The heat exchanger 220 then directly transfers heat from the sodium circulation loop to the CO2 in the secondary loop. The supercritical carbon dioxide power generation module 300 in the secondary loop uses a recompression Brayton cycle, achieving a cycle power generation efficiency of approximately 50%.

[0068] In the case of a reactor system in which the sodium coolant branch 240 is in operation, taking the operation of only one reactor 100 as an example, the sodium temperature at the inlet of the core 110 is designed to be 330°C. With a temperature rise of 80°C for a single core 110, the sodium temperature at the outlet of the core 110 is 410°C. The heat in the sodium circulation loop is then directly transferred to the CO2 in the secondary loop by the heat exchanger 220. The supercritical carbon dioxide power generation module 300 in the secondary loop generates electricity using the recompression Brayton cycle described above, achieving a cycle power generation efficiency of approximately 38%.

[0069] In an embodiment of the present invention, a supercritical carbon dioxide recompression cycle is used to generate electricity, replacing the traditional steam power generation system. This reduces the plant volume of the sodium-cooled reactor system and reduces protection costs. Compared to traditional sodium-cooled fast reactors, the multi-reactor series loop sodium-cooled fast reactor in this embodiment increases power generation efficiency by approximately 10%, significantly improving profitability. The sodium-cooled reactor system in this embodiment achieves enhanced overall system safety while also improving thermal efficiency and economic efficiency, promoting the large-scale commercial application of sodium-cooled fast reactors.

[0070] Regarding the embodiments of the present invention, it should also be noted that, in the absence of conflict, the embodiments of the present invention and the features therein may be combined with each other to obtain new embodiments.

[0071] The above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. The protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A sodium-cooled reactor system, characterized in that: include: A plurality of reactors, each reactor comprising a reactor vessel, a reactor core, and a sodium coolant, wherein the sodium coolant is contained in the reactor vessel, the reactor core is disposed in the reactor vessel, and the sodium coolant is used to absorb heat from the reactor core; a sodium pipeline connected between the stack containers of the multiple reactors, for connecting the stack containers of the multiple reactors in series to form a sodium circulation loop, wherein the sodium coolant circulates in the stack containers of the multiple reactors and the sodium pipeline; a heat exchange device connected to the sodium pipeline and used to cool the sodium coolant after absorbing the core heat; A sodium driving device is connected to the sodium pipeline and is used for driving the sodium coolant to circulate in the sodium circulation loop.

2. The system according to claim 1, wherein: Also includes: A plurality of sodium coolant branches are provided, each of the sodium coolant branches is correspondingly arranged outside each of the reactors, and the sodium coolant branches are connected in parallel to the reactor vessel.

3. The system according to claim 1, wherein: Also includes: a supercritical carbon dioxide power generation module, wherein carbon dioxide circulates in the supercritical carbon dioxide power generation module; Wherein, the heat exchange device is connected to the supercritical carbon dioxide power generation module, and the heat exchange device is used to transfer the heat of the sodium coolant to the carbon dioxide.

4. The system according to claim 3, characterized in that The supercritical carbon dioxide power generation module includes: a turbine device connected to the heat exchange device, wherein the carbon dioxide circulates between the turbine device and the heat exchange device, and the turbine device is used to convert the thermal energy of the carbon dioxide into mechanical energy; A power generation device is connected to the turbine device and is used to convert the mechanical energy into electrical energy.

5. The system according to claim 4, characterized in that The supercritical carbon dioxide power generation module also includes: a first compression device connected between the turbine device and the heat exchange device, for compressing carbon dioxide discharged from the turbine device, wherein the compressed carbon dioxide is transported to the heat exchange device to absorb heat from the sodium coolant; a first heat recovery device connected between the turbine device and the first compression device, the first heat recovery device being used to cool carbon dioxide discharged from the turbine device, and the cooled carbon dioxide is transported to the first compression device; a cooling device, connected between the first heat recovery device and the first compression device, for cooling the carbon dioxide; The carbon dioxide discharged from the turbine device flows through the first heat recovery device, the cooling device, and the first compression device in sequence for cooling and compression.

6. The system according to claim 5, characterized in that The first heat recovery device is also connected between the first compression device and the heat exchange device, and is used to transfer the waste heat of the carbon dioxide discharged from the turbine device to the carbon dioxide compressed by the first compression device; Among them, the carbon dioxide discharged from the turbine device flows through the first heat recovery device, the cooling device and the first compression device in sequence for cooling and compression, and the carbon dioxide compressed by the first compression device flows through the first heat recovery device and the heat exchange device in sequence for heating, and the compressed and heated carbon dioxide flows into the turbine device again.

7. The system according to claim 6, characterized in that The supercritical carbon dioxide power generation module also includes: a second heat recovery device connected between the turbine device and the first heat recovery device, for cooling carbon dioxide discharged from the turbine device; The second heat recovery device is further connected between the first heat recovery device and the heat exchange device, and is used to transfer the waste heat of the carbon dioxide discharged from the turbine device to the compressed carbon dioxide; The carbon dioxide discharged from the turbine device flows through the second heat recovery device, the first heat recovery device and the first compression device in sequence to be cooled and compressed, and then flows into the first heat recovery device, the second heat recovery device and the heat exchange device again to be heated.

8. The system according to claim 7, characterized in that The supercritical carbon dioxide power generation module also includes: a second compression device connected between the first reheat device and the second reheat device, for compressing part of the carbon dioxide cooled by the first reheat device, and the carbon dioxide compressed by the second compression device is transported to the second reheat device for heating; The first compression device is used to compress another portion of the carbon dioxide after being cooled by the first heat recovery device.

9. The system according to claim 1, wherein: The reactor further comprises: an outlet pipe, the outlet pipe being provided on the reactor container and being used for connecting the reactor container and the sodium pipeline outside the reactor; At least one control valve is provided on the outlet pipe and is used to control the circulation of the sodium coolant in the outlet pipe.

10. The system according to claim 9, characterized in that A siphon breaking device is provided at the pipe opening of the outlet pipe in the stack container, for limiting leakage of the sodium coolant in the stack container.

11. The system according to claim 9, wherein: Also includes: At least one sodium process room, the sodium pipeline is arranged in the sodium process room, and the sodium process room is filled with inert gas.

12. The system according to claim 11, wherein: Also includes: The alarm module is partially arranged in the sodium process room and is used for giving an alarm when sodium combustion occurs in the sodium process room.

13. The system according to claim 12, wherein: The alarm module includes: a gas detection device, disposed in the sodium process room, for detecting gas composition in the sodium process room; An alarm device, used for sounding an alarm; The alarm control device is connected to the gas detection device and the alarm device respectively, and is used to receive the detection signal of the gas detection device and control the alarm device according to the detection signal.

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