Passive miniature nuclear power generation device

Abstract

The invention belongs to the field of passive nuclear power generation, and relates to a passive miniature nuclear power generation device. Reactor core nuclear fuel and a control rod for controlling reactivity of a reactor core are mounted at the middle lower part in the reactor container; a control rod driving mechanism for driving the control rod to move up and down is mounted at the top of the reactor container; the reactor container is filled with a liquid metal coolant; the hot end of the thermoelectric device is communicated with the primary loop side liquid metal coolant heat exchange pipe to provide a high-temperature function of thermoelectric conversion, the cold end of the thermoelectric device is communicated with the secondary loop side cooling water heat exchange pipe to provide a low-temperature function of thermoelectric conversion, thermoelectric conversion is achieved through temperature difference heat energy formed by the high temperature of the hot end and the low temperature of the cold end, and therefore electric energy is generated. The natural convection air cooling heat exchanger is installed on the thermoelectric device and used for discharging waste heat of the thermoelectric device and maintaining the temperature of the cold end. The passive nuclear power generation function is achieved, and the passive nuclear power generation device has the advantages of being high in inherent safety, simple in structure, compact in size, convenient to disassemble, assemble and transport, high in reliability and the like.

Description

Technical Field

[0001] The present invention belongs to the field of passive nuclear power generation, and in particular relates to a passive micro nuclear power generation device. Background Art

[0002] Mineral resource development and comprehensive base support in remote onshore areas (plateaus, mountainous areas, isolated islands, deserts, etc.) require long-term, continuous, stable, reliable, small-capacity power loads (about 0.1 to 10 MWe). Traditional fossil energy security and environmental adaptability are limited. Wind power and solar energy are restricted by geographical and climatic environments and are difficult to meet the power needs of specific users.

[0003] The passive micro-nuclear power generation device has good environmental adaptability. The reactor can operate at full power for 2 to 5 years after a single loading. The design takes into account multiple factors such as improved safety, simplified on-site construction, flexible deployment, modular customization, mass production and simplified operation. It has innovative technical features such as high inherent safety, easy modularization and expansion, convenient truck transportation and deployment, and easy unmanned autonomous operation. It can meet the long-term stable and continuous power generation energy security needs of special users in remote areas. Summary of the Invention

[0004] The purpose of the present invention is to provide a passive micro-nuclear power generation device. The device utilizes nuclear energy technology and the principles of direct thermoelectric conversion technology, and realizes the passive nuclear power generation function through the reasonable arrangement and design of the reactor heat source device, the thermoelectric conversion device, and the air natural convection cooling device. The device has the advantages of high inherent safety, simple structure, compact size, easy disassembly and transportation, and high reliability. It effectively overcomes the problems of power supply stability, long-term sustainability, and reliability existing in the use of fossil fuels and wind power and photovoltaic power plants in remote land areas, and solves the problem of long-term power supply with limited capacity in remote areas.

[0005] The technical solution for achieving the purpose of the present invention is as follows:

[0006] A passive micro-nuclear power generation device comprises: a reactor vessel, core nuclear fuel, control rods, a control rod drive mechanism, liquid metal coolant, a thermoelectric device, and a natural convection air cooling heat exchanger; the core nuclear fuel and control rods for core reactivity control are installed in the middle and lower part of the reactor vessel, and the control rods are connected to the control rod drive mechanism; the reactor vessel is filled with liquid metal coolant; the hot end of the thermoelectric device is connected to the liquid metal coolant heat exchange pipe on the primary circuit side to provide a high-temperature function of thermoelectric conversion, and the cold end of the thermoelectric device is connected to the cooling water heat exchange pipe on the secondary circuit side to provide a low-temperature function of thermoelectric conversion, and the temperature difference heat energy formed by the hot end high temperature and the cold end low temperature is used to realize the thermoelectric conversion function, thereby generating electricity; the cold end of the thermoelectric device is installed with a natural convection air cooling heat exchanger for discharging waste heat of the thermoelectric device and maintaining the low temperature of the cold end.

[0007] The thermoelectric device includes: a primary heat transfer pipe, a hot-end structural material of the thermoelectric device, a cold-end structural material of the thermoelectric device, and a secondary heat transfer pipe; the inlet and outlet of the primary heat transfer pipe are connected to a liquid metal coolant, the inlet and outlet of the secondary heat transfer pipe are connected to a natural convection air cooling heat exchanger, and the hot-end structural material of the thermoelectric device and the cold-end structural material of the thermoelectric device are arranged between the primary heat transfer pipe and the secondary heat transfer pipe; the high-temperature heat of the liquid metal coolant is transferred to the hot-end structural material of the thermoelectric device through the primary heat transfer pipe, the temperature of the cold-end structural material of the thermoelectric device is maintained through the secondary heat transfer pipe, and waste heat of the secondary heat transfer pipe is discharged through the natural convection air cooling heat exchanger; direct current is generated through the thermoelectric effect of the temperature difference between the hot-end structural material of the thermoelectric device and the cold-end structural material of the thermoelectric device.

[0008] An argon blanket is provided on the upper portion of the reactor vessel to compensate for thermal expansion and contraction of the liquid metal coolant and to regulate pressure.

[0009] The device further comprises a DC-AC converter, which is connected to the thermoelectric device hot end structural material and the thermoelectric device cold end structural material of the thermoelectric device to convert DC power into AC power.

[0010] The device also includes a secondary circuit nitrogen pressure stabilizer, which is installed on the secondary circuit heat transfer pipe and is used to perform pressure and volume compensation adjustment on the cooling medium water in the secondary circuit heat transfer pipe.

[0011] The natural convection air cooling heat exchanger adopts a fin-tube heat exchanger to conduct waste heat in a natural convection manner.

[0012] The fin-tube heat exchanger comprises an external fin heat exchange tube bundle and a support structure, and the support structures are installed on the support structure at equal intervals.

[0013] The external fin heat exchange tube bundle adopts high-density fins with folded angles, and the fins are arranged at equal intervals on the heat exchange tube bundle.

[0014] The fin tube heat exchanger can be single-stage, double-stage or multi-stage.

[0015] The beneficial technical effects of the present invention are:

[0016] 1. The passive micro-nuclear power generation device provided by the present invention overcomes the technical deficiencies of traditional fossil energy (thermal power plants), new energy (wind power, solar power), and long-distance high-voltage power transmission in the application of remote areas. By utilizing the principles of nuclear energy technology and direct thermoelectric conversion technology, and through the rational arrangement and design of the reactor heat source device, thermoelectric conversion device, and air natural convection cooling device, the passive nuclear power generation function is realized.

[0017] 2. The present invention provides a passive micro-nuclear power generation device that has the advantages of being independent of active mechanical equipment, having strong inherent safety, a compact structure, and good environmental adaptability. The system operation does not require human intervention or long-term power supply guarantee facilities. At the same time, it utilizes air as a heat well and uses a natural convection air cooler to achieve waste heat discharge and post-shutdown decay heat discharge, greatly improving the inherent heat removal capacity of the micro-nuclear power device.

[0018] 3. In the passive micro-nuclear power generation device provided by the present invention, the primary liquid metal heat transfer system is an independent closed natural circulation system that does not require active mechanical equipment (such as a pump), which not only simplifies the number of system equipment components but also improves the inherent safety of operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic structural diagram of a passive micro-nuclear power generation device provided by the present invention;

[0020] Figure 2 This is a schematic cross-sectional view of a core fuel assembly in a passive micro-nuclear power generation device provided by the present invention;

[0021] Figure 3 A schematic cross-sectional view of a thermoelectric device in a passive micro-nuclear power generation device provided by the present invention;

[0022] Figure 4 This is a schematic structural diagram of a fin-tube heat exchanger in a passive micro-nuclear power generation device provided by the present invention;

[0023] Figure 5 Schematic diagram of the structure of a single-stage fin-tube heat exchanger in the real-time mode of the present invention;

[0024] Figure 6 This is a structural diagram of a two-stage fin-tube heat exchanger in the real-time mode of the present invention. DETAILED DESCRIPTION

[0025] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0026] like Figure 1-6 As shown, the present invention provides a passive micro-nuclear power generation device that utilizes liquid metal-cooled micro-reactor technology to generate electricity. The device comprises: a reactor vessel 1, a core nuclear fuel 2, control rods 3, a control rod drive mechanism 4, an argon blanket 5, a liquid metal coolant 6, a thermoelectric device 7, a secondary nitrogen pressure regulator 8, a natural convection air-cooled heat exchanger 9, and a DC / AC converter 12.

[0027] like Figure 1As shown, a core nuclear fuel 2 and a control rod 3 for core reactivity control are installed in the middle and lower part of the reactor vessel 1, and the control rod 3 is connected to a control rod drive mechanism 4; the reactor vessel 1 is filled with a liquid metal coolant 6; the hot end of the thermoelectric device 7 is connected to the liquid metal coolant 6 heat exchange pipe on the primary circuit side, providing a high-temperature function of thermoelectric conversion, and the cold end of the thermoelectric device 7 is connected to the cooling water heat exchange pipe on the secondary circuit side, providing a low-temperature function of thermoelectric conversion. The temperature difference heat energy formed by the high temperature at the hot end and the low temperature at the cold end is used to realize the thermoelectric conversion function, thereby generating electricity; a natural convection air cooling heat exchanger 9 is installed on the cold end of the thermoelectric device 7 to discharge the waste heat of the thermoelectric device 7 and maintain the low temperature of the cold end.

[0028] like Figure 2 As shown, the core nuclear fuel 2 is arranged in a compact hexagonal shape.

[0029] like Figure 3 As shown, the thermoelectric device 7 includes a primary heat transfer pipe 13, a thermoelectric device hot-end structural material 14, a thermoelectric device cold-end structural material 15, and a secondary heat transfer pipe 16. The inlet and outlet of the primary heat transfer pipe 13 are connected to the liquid metal coolant 6, while the inlet and outlet of the secondary heat transfer pipe 16 are connected to the natural convection air cooling heat exchanger 9. The high-temperature heat of the liquid metal coolant 6 is transferred to the thermoelectric device hot-end structural material 14 through the primary heat transfer pipe 13, and the temperature of the thermoelectric device cold-end structural material 15 is maintained through the secondary heat transfer pipe 16. Waste heat from the secondary heat transfer pipe 16 is discharged through the natural convection air cooling heat exchanger 9. Direct current is generated through the thermoelectric effect of the temperature difference between the thermoelectric device hot-end structural material 14 and the thermoelectric device cold-end structural material 15.

[0030] The number and length of the primary heat transfer tubes 13 and the secondary heat transfer tubes 16 in the thermoelectric device 7 depend on the thermal power of the reactor.

[0031] An argon blanket 5 is provided on the upper portion of the reactor vessel 1 to absorb volume fluctuations of the liquid metal coolant 6, compensate for thermal expansion and contraction of the liquid metal coolant 6, and maintain the liquid metal coolant 6 in the reactor vessel 1; at the same time, the pressure of the reactor vessel 1 is regulated.

[0032] The DC-AC converter 12 is connected to the thermoelectric device hot end structural material 14 and the thermoelectric device cold end structural material 15 of the thermoelectric device 7 to convert direct current into alternating current.

[0033] A secondary circuit nitrogen pressure stabilizer 8 is installed on the secondary circuit heat transfer pipe 16 to compensate and adjust the pressure and volume of the cooling water in the secondary circuit heat transfer pipe 16 .

[0034] The natural convection air cooling heat exchanger 9 uses a fin-tube heat exchanger 17 to remove waste heat by natural convection. Cold air flows in from the inlet at the bottom of the natural convection air cooling heat exchanger 9, flows upward along the V-shaped high-efficiency fin-tube heat exchanger 17 at the bottom, and cools the liquid in the tube. The air then turns into hot air and flows out from the upper side of the inverted V-shaped high-efficiency fin-tube heat exchanger 17. Depending on the waste heat load, the natural convection air cooling heat exchanger 9 can be configured with a single-stage, two-stage, or multi-stage fin-tube heat exchanger 17, such as Figure 5 、 Figure 6 shown.

[0035] like Figure 1 、 Figure 4 As shown, the fin-tube heat exchanger 17 includes an outer fin heat exchange tube bundle 10 and a support structure 11, on which the support structures 11 are evenly spaced. The outer fin heat exchange tube bundle 10 uses high-density fins with folded angles, and the fins are evenly spaced on the heat exchange tube bundle.

[0036] The present invention provides a passive micro-nuclear power generation device, comprising: a core fuel assembly for generating thermal energy; control rods and their drive mechanism for controlling the core's thermal power; a reactor vessel housing the core; a liquid metal coolant for transferring core heat to the hot end of the thermoelectric device; an argon gas chamber for compensating for coolant expansion and contraction and regulating pressure; a thermoelectric device for thermoelectric conversion; and a DC / AC converter for converting DC to AC; a primary heat transfer tube bundle for transferring core heat to the hot end surface of the thermoelectric device; a secondary heat transfer tube bundle for maintaining the temperature of the cold end surface of the thermoelectric device; a natural convection air cooler for passively discharging waste heat through natural convection; and a nitrogen pressure regulator. Its operating principle is as follows:

[0037] When the control rod drive mechanism 4 withdraws the control rods 3 inserted into the core, nuclear fission reactions occur in the core's nuclear fuel elements, generating heat energy in the core. The liquid metal coolant's density decreases as it heats, generating buoyancy and causing it to flow upward. This heat is then transferred to the hot-end structural material 14 of the thermoelectric device 7 through the primary heat transfer tubes 13. This lowers the coolant's temperature and increases its density, generating driving force and achieving primary natural circulation. An inert gas blanket 5, argon, is placed above the reactor vessel 1 to absorb volume fluctuations in the liquid metal coolant and maintain its presence within the vessel.

[0038] In the thermoelectric device, the hot-end structural material 14 of the thermoelectric device is the high-temperature end, and the cold-end structural material 15 of the thermoelectric device is the low-temperature end. The high-temperature heat of the coolant is transferred to the hot-end structural material 14 of the thermoelectric device by the primary heat transfer pipe 13, and the waste heat is removed by the secondary heat transfer pipe 16 while maintaining the temperature of the cold-end structural material 15 of the thermoelectric device. The temperature difference between the hot-end structural material 14 and the cold-end structural material 15 of the thermoelectric device is used to directly produce electricity from the thermoelectric special materials, and the DC-AC converter 12 is used to realize AC output.

[0039] The waste heat discharge device of the secondary circuit adopts a natural convection air cooling heat exchanger 9. The natural convection air cooling heat exchanger 9 adopts an angled high-density fin tube air heat exchanger 17 to maintain the temperature of the cold end structural material 15 of the thermoelectric device of the thermoelectric device, ensuring a certain thermoelectric conversion efficiency. By reasonably designing the cold air inlet, fin arrangement, and hot air flow channel, efficient air natural convection heat exchange is achieved.

[0040] The passive micro-nuclear power generation device provided by the present invention is used to generate electricity. The specific process is as follows:

[0041] 1. Heat energy generation: Nuclear fission reaction occurs in the nuclear fuel elements, generating heat energy in the core;

[0042] 2. Heat transfer: The natural flow of liquid metal coolant is used to achieve heat transfer. The heat energy generated by the reactor core is transferred from the reactor core to the hot end face of the thermoelectric device. The flow is distributed to the contents of each cooling tube bundle through the core outlet coolant distributor. The heat of the coolant is transferred to the hot end face of the thermoelectric device by heat conduction within the tube bundle.

[0043] 3. Thermoelectric production: Utilize the thermoelectric effect of thermoelectric materials to produce direct current, and use a DC-AC converter to achieve AC output;

[0044] 4. Waste heat discharge: An angled fin tube air heat exchanger is used to maintain the temperature of the cold end surface of the thermoelectric device to ensure the efficiency of thermoelectric conversion, while the waste heat is discharged by natural convection of air;

[0045] 5. Natural circulation: The entire process of the passive micro-nuclear power generation device adopts full natural circulation operation, and the power production method adopts a purely static mode. Before starting operation, the system operating status parameters are pre-debugged to ensure that the system meets the power automatic operation range, and then the system realizes power output in natural circulation and automatic control mode.

[0046] The present invention has been described in detail above with reference to the accompanying drawings and embodiments. However, the present invention is not limited to the above embodiments. Various modifications can be made within the scope of knowledge possessed by those skilled in the art without departing from the spirit of the present invention. Any content not described in detail in the present invention may be adapted from existing technologies.

Claims

1. A passive micro-nuclear power generation device, characterized in that: The device comprises: a reactor vessel (1), a core nuclear fuel (2), a control rod (3), a control rod driving mechanism (4), a liquid metal coolant (6), a thermoelectric device (7), and a natural convection air cooling heat exchanger (9); the core nuclear fuel (2) and a control rod (3) for controlling the core reactivity are installed in the middle and lower part of the reactor vessel (1), and the control rod (3) is connected to the control rod driving mechanism (4); the reactor vessel (1) is filled with the liquid metal coolant (6) The hot end of the thermoelectric device (7) is connected to the liquid metal coolant (6) heat exchange pipe on the first circuit side to provide a high-temperature function of thermoelectric conversion. The cold end of the thermoelectric device (7) is connected to the cooling water heat exchange pipe on the second circuit side to provide a low-temperature function of thermoelectric conversion. The temperature difference heat energy formed by the high temperature at the hot end and the low temperature at the cold end is used to realize the thermoelectric conversion function, thereby producing electric energy. The cold end of the thermoelectric device (7) is equipped with a natural convection air cooling heat exchanger (9) for discharging waste heat of the thermoelectric device (7) and maintaining the low temperature of the cold end.

2. A passive micro-nuclear power generation device according to claim 1, characterized in that: The thermoelectric device (7) comprises: a primary heat transfer tube (13), a thermoelectric device hot end structural material (14), a thermoelectric device cold end structural material (15), and a secondary heat transfer tube (16); the inlet and outlet of the primary heat transfer tube (13) are connected to the liquid metal coolant (6), the inlet and outlet of the secondary heat transfer tube (16) are connected to the natural convection air cooling heat exchanger (9), and the thermoelectric device hot end structural material (14), the thermoelectric device cold end structural material (15) are provided between the primary heat transfer tube (13) and the secondary heat transfer tube (16). A cold end structural material (15) is placed; the high temperature heat of the liquid metal coolant (6) is transferred to the hot end structural material (14) of the thermoelectric device through a first-loop heat transfer pipe (13); the temperature of the cold end structural material (15) of the thermoelectric device is maintained through a second-loop heat transfer pipe (16); the waste heat of the second-loop heat transfer pipe (16) is discharged through a natural convection air cooling heat exchanger (9); direct current is generated through the temperature difference thermoelectric effect between the hot end structural material (14) of the thermoelectric device and the cold end structural material (15) of the thermoelectric device.

3. A passive micro-nuclear power generation device according to claim 1, characterized in that: An argon covering layer (5) is provided at the upper part of the reactor container (1) for compensating for thermal expansion and contraction of the liquid metal coolant (6) and for pressure regulation.

4. A passive micro-nuclear power generation device according to claim 1, characterized in that: The device further comprises a DC-AC converter (12), which is connected to the thermoelectric device hot end structural material (14) and the thermoelectric device cold end structural material (15) of the thermoelectric device (7) to convert direct current into alternating current.

5. A passive micro-nuclear power generation device according to claim 1, characterized in that: The device also includes a secondary circuit nitrogen pressure stabilizer (8), which is installed on the secondary circuit heat transfer pipe (16) and is used to perform pressure and volume compensation adjustment on the cooling medium water in the secondary circuit heat transfer pipe (16).

6. A passive micro-nuclear power generation device according to claim 1, characterized in that: The natural convection air cooling heat exchanger (9) adopts a fin tube heat exchanger (17) to discharge waste heat by natural convection of air.

7. A passive micro-nuclear power generation device according to claim 6, characterized in that: The fin-tube heat exchanger (17) comprises an external fin heat exchange tube bundle (10) and a support structure (11), and the support structures (11) are installed on the support structure (11) at equal intervals.

8. A passive micro-nuclear power generation device according to claim 7, characterized in that: The external fin heat exchange tube bundle (10) adopts high-density fins with folded angles, and the fins are arranged at equal intervals on the heat exchange tube bundle.

9. A passive micro-nuclear power generation device according to claim 6, characterized in that: The fin-tube heat exchanger (17) may be single-stage, dual-stage or multi-stage.

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