Dual-mode self-starting residual heat removal system for heat pipe reactor

Abstract

The invention discloses a dual-mode self-starting residual heat removal system for a heat pipe reactor, which belongs to the technical field of nuclear reactor safety, and comprises a heat pipe heat exchanger for dissipating heat of a plurality of heat pipes; the air cooling system comprises an air channel formed in the heat pipe heat exchanger, the heat pipe is located in the air channel, circulation openings are formed in the top and the bottom of the air channel respectively, and when the heat pipe heat exchanger fails, the circulation openings are opened to communicate with the external atmosphere. The waste heat removal heat exchanger is provided with an inner-layer cavity and an outer-layer cavity, the inner-layer cavity and the outer-layer cavity are both filled with molten metal used for heat conduction, the heat pipe penetrates through the inner-layer cavity, and a self-opening assembly is arranged between the inner-layer cavity and the outer-layer cavity. And the self-opening assembly is automatically opened. According to the invention, self-starting dual-mode residual heat removal can be realized under extreme conditions, and the residual heat removal capability and safety margin of the heat pipe reactor system under accident and shutdown conditions are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of nuclear reactor safety, and particularly to a dual-mode self-starting residual heat removal system for a heat pipe reactor. Background Art

[0002] A heat pipe cooled reactor is an advanced reactor that uses heat pipes to export the heat of the reactor core. Compared with traditional light water reactors, heat pipe reactors can achieve high modularity and simplification, have excellent inherent safety characteristics and low maintenance costs. This makes it have broad application prospects in the fields of small nuclear power plants, power supply in remote areas, and energy supply for aerospace and offshore platforms.

[0003] However, currently, for the passive residual heat removal system of heat pipe cooled reactors, it mainly relies on a single residual heat removal design scheme. When this system fails or is insufficient to export the remaining heat of the reactor core, the temperature of the reactor core may continue to rise, leading to fuel damage and serious safety hazards.

[0004] Therefore, a dual-mode self-starting residual heat removal system for a heat pipe reactor is proposed. Summary of the Invention

[0005] The object of the present invention is to provide a dual-mode self-starting residual heat removal system for a heat pipe reactor, aiming to solve or improve at least one of the above technical problems.

[0006] To achieve the above object, the present invention provides the following solution: The present invention provides a dual-mode self-starting residual heat removal system for a heat pipe reactor, including:

[0007] A heat pipe heat exchanger, wherein the circulating cooling medium in the heat pipe heat exchanger is used to dissipate heat from a plurality of heat pipes. One end of each heat pipe is inserted into the core of the heat pipe reactor, and the other end is inserted into the heat pipe heat exchanger;

[0008] An air cooling system, which includes an air channel opened in the heat pipe heat exchanger. The heat pipes are located in the air channel, and through openings are respectively provided at the top and bottom of the air channel. When the heat pipe heat exchanger fails, the through openings open to communicate with the external atmosphere;

[0009] A residual heat removal heat exchanger, which has an inner chamber and an outer chamber. Both the inner chamber and the outer chamber are filled with a metal liquid for heat conduction. The heat pipes penetrate through the inner chamber, and a self-opening component is provided between the inner chamber and the outer chamber. When the heat pipe heat exchanger fails and the temperature of the heat pipes exceeds a preset temperature, the self-opening component automatically opens, causing the metal liquid between the inner chamber and the outer chamber to flow in a self-driven manner.

[0010] Optionally, the waste heat discharge heat exchanger includes an outer shell, and an inner ring sleeve is fixedly connected inside the outer shell. The inner ring sleeve divides the inner space of the outer shell into the inner chamber and the outer chamber, and the outer chamber is wound around the outer of the inner chamber.

[0011] Optionally, the self-opening component includes a plurality of flow channels opened on the inner ring sleeve. Both ends of the flow channel are respectively communicated with the inner chamber and the outer chamber. A sealing plug is inserted into one end of the flow channel facing the outer chamber. A heat expansion member is arranged in the inner chamber, and the heat expansion member is connected to the sealing plug. When the heat pipe heat exchanger fails, the heat expansion member expands due to heat, thereby squeezing the sealing plug to make the sealing plug pop out of the flow channel.

[0012] Optionally, the heat expansion member includes an annular metal plate arranged in the inner chamber. There is a gap between the annular metal plate and the inner ring sleeve. The annular metal plate is wound around the outside of a plurality of the heat pipes. A plurality of through holes communicated with the flow channels are opened on the annular metal plate. A plurality of ejector rods are fixedly connected to the outer wall of the annular metal plate. The plurality of ejector rods are arranged in one-to-one correspondence with the plurality of sealing plugs. One end of the ejector rod away from the annular metal plate extends into the flow channel and is fixedly connected to the sealing plug.

[0013] Optionally, the flow channel includes a main flow channel. One end of the main flow channel is communicated with two sub-flow channels. The ejector rod is located between the two sub-flow channels. The ejector rod penetrates the side wall of the inner ring sleeve and extends into the main flow channel to be fixedly connected to the sealing plug.

[0014] Optionally, the air cooling system further includes an air inlet pipe and an air outlet pipe. The air inlet pipe is fixedly connected and communicated with the flow port at the bottom of the air channel, and the air outlet pipe is fixedly connected and communicated with the flow port at the top of the air channel. A first control valve and a second control valve are respectively fixedly connected to the air inlet pipe and the air outlet pipe.

[0015] Optionally, the first control valve and the second control valve are closed when powered on and opened when powered off.

[0016] Optionally, a chimney is fixedly connected and communicated with the top of the air outlet pipe.

[0017] Optionally, a plurality of heat dissipation fins are arranged on the outer wall of the outer shell.

[0018] Optionally, the heat pipe heat exchanger provides a circulating cooling medium through a Brayton cycle system. The Brayton cycle system includes a turbine, a compressor, a generator, a regenerator, and a pre-cooler;

[0019] The inlet of the turbine is communicated with the outlet of the cooling channel of the heat pipe heat exchanger. The outlet of the turbine is communicated with the first inlet of the regenerator. The first outlet of the regenerator is communicated with the inlet of the pre-cooler. The outlet of the pre-cooler is communicated with the inlet of the compressor. The outlet of the compressor is communicated with the second inlet of the regenerator. The second outlet of the regenerator is communicated with the inlet of the cooling channel of the heat pipe heat exchanger. The generator is drivingly connected with the turbine. Third valves and fourth valves are respectively arranged on the pipelines at the inlet end and the outlet end of the cooling channel of the heat pipe heat exchanger.

[0020] The present invention discloses the following technical effects:

[0021] 1. When the heat pipe heat exchanger stops operating due to various failures such as accidents, the flow ports at the top and bottom of the air channel in the heat pipe heat exchanger are opened. The temperature in the heat pipe is transferred to the air channel, causing the air inside to heat up. The heated air flows upward and exits through the flow port at the top, and the external low-temperature air enters the air channel through the flow port at the bottom, thereby forming natural air flow to dissipate heat from the heat pipes in the heat pipe heat exchanger. When the air cooling system alone is not sufficient to completely remove the core heat and the heat pipe temperature continues to rise, the self-opening component is activated, enabling the inner chamber and the outer chamber to communicate. The temperature of the molten metal in the inner chamber is higher than that in the outer chamber. Under the action of natural circulation of hot and cold fluids, the molten metal begins to flow, conducting the heat of the heat pipe to the outer chamber, and further dissipating heat to the atmospheric environment.

[0022] 2. The present invention makes full use of the heat transfer characteristics of the heat pipe and introduces multi-level waste heat discharge paths. In the face of different environmental conditions and accident types, the reactor adaptively switches between the natural convection air cooling mode in the air cooling system for heat dissipation and the dual-mode waste heat discharge jointly acting with the more efficient waste heat discharge heat exchanger, not only improving the efficiency and stability of waste heat discharge, but also providing a more adaptable technical solution for the safe deployment of small-scale and distributed nuclear energy facilities and energy supply in remote areas.

[0023] 3. The present invention improves the safety and controllability of the heat pipe-cooled reactor under accident conditions and shutdown scenarios as a whole. By realizing automatic waste heat export without external power support, the risk of excessive increase in core temperature can be effectively reduced, laying a solid foundation for the popularization and reliable operation of future nuclear energy applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The drawings constituting a part of this application are used to provide a further understanding of this application. The schematic embodiments of this application and their descriptions are used to explain this application and do not constitute an improper limitation to this application. In the drawings:

[0025] Figure 1 is a schematic structural diagram of the present invention;

[0026] Figure 2 This is a schematic structural diagram of the waste heat discharge heat exchanger in the present invention;

[0027] Figure 3 This is a schematic structural diagram of the flow passage in the present invention.

[0028] In the figure: 1. Heat pipe stack core; 2. Heat pipe; 3. Waste heat discharge heat exchanger; 4. Heat pipe heat exchanger; 5. Brayton cycle system; 6. Inner chamber; 7. Outer chamber; 8. Chimney; 9. Turbine; 10. Compressor; 11. Generator; 12. Regenerator; 13. Pre-cooler; 14. Cooling water pump; 15. Annular metal plate; 16. Flow passage; 161. Total flow channel; 162. Divided flow channel; 17. Sealing plug; 18. Outer shell; 19. Inner ring sleeve; 20. First control valve; 21. Second control valve; 22. Third valve; 23. Fourth valve; 24. Thumb rod; 25. Air inlet pipe; 26. Air outlet pipe. Detailed implementation manners

[0029] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0030] To make the above objects, features, and advantages of the present invention more obvious and understandable, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific implementation manners.

[0031] Referring to Figures 1 - 3 , the present invention provides a dual-mode self-starting waste heat discharge system for a heat pipe stack, including:

[0032] A heat pipe heat exchanger 4, and the circulating cooling medium in the heat pipe heat exchanger 4 is used to dissipate heat from a plurality of heat pipes 2. One end of each heat pipe 2 is inserted into the heat pipe stack core 1, and the other end is inserted into the heat pipe heat exchanger 4; a working medium circulates in the heat pipe 2 for heat transfer;

[0033] An air cooling system, which includes an air passage opened in the heat pipe heat exchanger 4. The heat pipes 2 are located in the air passage, and circulation openings are respectively provided at the top and bottom of the air passage. When the heat pipe heat exchanger 4 fails, the circulation openings are opened to communicate with the external atmosphere;

[0034] The residual heat removal heat exchanger 3 has an inner chamber 6 and an outer chamber 7. Both the inner chamber 6 and the outer chamber 7 are filled with a metal liquid for heat conduction. The heat pipe 2 passes through the inner chamber 6. A self-opening component is arranged between the inner chamber 6 and the outer chamber 7. When the heat pipe heat exchanger 4 fails and the temperature of the heat pipe 2 exceeds a preset temperature, the self-opening component automatically opens, enabling the metal liquid between the inner chamber 6 and the outer chamber 7 to circulate driven by itself.

[0035] In some alternative embodiments, the residual heat removal heat exchanger 3 includes an outer housing 18. An inner ring sleeve 19 is fixedly connected inside the outer housing 18. The inner ring sleeve 19 divides the internal space of the outer housing 18 into an inner chamber 6 and an outer chamber 7. The outer chamber 7 is wound around the outer side of the inner chamber 6.

[0036] In some alternative embodiments, the self-opening component includes a plurality of flow channels 16 formed in the inner ring sleeve 19. Both ends of the flow channel 16 are respectively communicated with the inner chamber 6 and the outer chamber 7. A sealing plug 17 is inserted into one end of the flow channel 16 facing the outer chamber 7. A heat-expansion member is arranged in the inner chamber 6. The heat-expansion member is connected to the sealing plug 17. When the heat pipe heat exchanger 4 fails, the heat-expansion member expands due to heat, thereby squeezing the sealing plug 17 to make the sealing plug 17 pop out of the flow channel 16.

[0037] In some alternative embodiments, the heat-expansion member includes an annular metal plate 15 arranged in the inner chamber 6. There is a gap between the annular metal plate 15 and the inner ring sleeve 19. The annular metal plate 15 is wound around the outside of a plurality of heat pipes 2. A plurality of through holes communicating with the flow channels 16 are formed in the annular metal plate 15. A plurality of ejector rods 24 are fixedly connected to the outer wall of the annular metal plate 15. The plurality of ejector rods 24 are arranged in one-to-one correspondence with the plurality of sealing plugs 17. The end of the ejector rod 24 away from the annular metal plate 15 extends into the flow channel 16 and is fixedly connected to the sealing plug 17.

[0038] In some alternative embodiments, the flow channel 16 includes a main flow channel 161. One end of the main flow channel 161 communicates with two branch flow channels 162. The ejector rod 24 is located between the two branch flow channels 162. The ejector rod 24 penetrates the side wall of the inner ring sleeve 19 and extends into the main flow channel 161 to be fixedly connected to the sealing plug 17.

[0039] When the operating temperature of the heat pipe 2 rises due to insufficient heat dissipation, the metal liquid in the inner chamber 6 thermally expands, forming an internal pressure that squeezes the annular metal plate 15; when the temperature of the heat pipe 2 and the metal liquid in the inner chamber 6 rises to a predetermined value, the annular metal plate 15, under the combined action of thermal expansion and the internal pressure of the metal liquid, squeezes the sealing plug 17 and causes it to disengage from the flow channel 16; thereby opening the flow channel 16, enabling the inner chamber 6 and the outer chamber 7 to communicate, and the metal liquid naturally circulates under the drive of the temperature difference between hot and cold, conducting the heat in the inner chamber 6 into the outer chamber 7, and then transferring it to the outer housing 18 and releasing it to the atmosphere through the outer housing 18.

[0040] In a specific embodiment, there are two flow channels 16, which are arranged symmetrically up and down.

[0041] In a specific embodiment, the metal liquid is a sodium-potassium alloy.

[0042] In a specific embodiment, the working fluid of the heat pipe 2 is sodium.

[0043] In some alternative embodiments, the air-cooling system further includes an air inlet pipe 25 and an air outlet pipe 26. The air inlet pipe 25 is fixedly connected and communicated with the flow port at the bottom of the air channel, and the air outlet pipe 26 is fixedly connected and communicated with the flow port at the top of the air channel. A first control valve 20 and a second control valve 21 are respectively fixedly connected to the air inlet pipe 25 and the air outlet pipe 26.

[0044] In some alternative embodiments, the first control valve 20 and the second control valve 21 are closed when powered on and opened when powered off.

[0045] In some alternative embodiments, a chimney 8 is fixedly connected and communicated with the top of the air outlet pipe 26.

[0046] In a specific embodiment, the air inlet pipe 25 and the air outlet pipe 26 are respectively provided with flow guide plates.

[0047] Through the coordinated arrangement of the flow guide plates, the air flow path entering the air channel of the heat pipe heat exchanger 4 is optimized, guiding the air to fully wash the surface of the heat pipe 2 and improving the heat exchange efficiency.

[0048] In some alternative embodiments, a plurality of heat dissipation fins are arranged on the outer wall of the outer housing 18.

[0049] In some alternative embodiments, the heat pipe heat exchanger 4 is provided with a circulating cooling medium by a Brayton cycle system 5. The Brayton cycle system 5 includes a turbine 9, a compressor 10, a generator 11, a regenerator 12, and a pre-cooler 13;

[0050] The inlet of the turbine 9 is communicated with the outlet of the cooling channel of the heat pipe heat exchanger 4, the outlet of the turbine 9 is communicated with the first inlet of the regenerator 12, the first outlet of the regenerator 12 is communicated with the inlet of the precooler 13, the outlet of the precooler 13 is communicated with the inlet of the compressor 10, the outlet of the compressor 10 is communicated with the second inlet of the regenerator 12, and the second outlet of the regenerator 12 is communicated with the inlet of the cooling channel of the heat pipe heat exchanger 4; the generator 11 is drivingly connected with the turbine 9; the cooling water pump 14 is communicated with the inlet of the regenerator 12; a third valve 22 and a fourth valve 23 are respectively arranged on the pipelines at the inlet end and the outlet end of the cooling channel of the heat pipe heat exchanger 4.

[0051] The third valve 22 and the fourth valve 23 are automatically closed when powered off, and the first control valve 20 and the second control valve 21 are automatically opened when powered off. Thus, when a fault occurs, the valves can be opened or closed without external power, so as to automatically switch to the air natural circulation mode under accident conditions.

[0052] The application principle of the present invention is as follows:

[0053] When the Brayton cycle system 5 stops operating due to an accident, the third valve 22 and the fourth valve 23 are automatically closed when powered off, and the first control valve 20 and the second control valve 21 are automatically opened. Under the action of natural convection of hot and cold air, air flows through the air inlet pipe 25 into the heat pipe heat exchanger 4, then flushes the heat pipe 2 and then passes through the air outlet pipe 26 and is discharged from the chimney 8.

[0054] When the heat of the heat pipe reactor core 1 cannot be completely dissipated only by natural air circulation, the operating temperature of the heat pipe 2 rises, so that the annular metal plate 15 squeezes the sealing plug 17 to make it pop out under the action of the thermal expansion of the metal liquid in the inner chamber 6 and its own thermal expansion, and then the inner chamber 6 and the outer chamber 7 are communicated through the flow channel 16, and the metal liquid starts to flow under the action of natural circulation of hot and cold fluids, and the heat of the reactor is dissipated to the outer shell 18 and finally discharged into the atmospheric environment.

[0055] The present invention makes full use of the heat transfer characteristics of the heat pipe 2 and introduces multiple levels of waste heat discharge paths. Facing different environmental conditions and accident types, the reactor can adaptively switch between the natural convection air cooling mode and the more efficient dual-mode waste heat discharge, which not only improves the efficiency and stability of waste heat discharge, but also provides a more adaptable technical solution for the safe deployment of small-scale and distributed nuclear energy facilities and energy supply in remote areas.

[0056] In the description of the present invention, it should be understood that the orientation or positional relationships indicated by the terms "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. are based on the orientation or positional relationships shown in the drawings, and are only for the convenience of describing the present invention, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the present invention.

[0057] The embodiments described above are only for describing the preferred mode of the present invention, and do not limit the scope of the present invention. Without departing from the design spirit of the present invention, various deformations and improvements made by those of ordinary skill in the art to the technical solutions of the present invention shall fall within the protection scope determined by the claims of the present invention.

Claims

1. A dual-mode self-starting residual heat removal system for a heat pipe stack, characterized in that: include: A heat pipe heat exchanger (4), wherein a circulating cooling medium in the heat pipe heat exchanger (4) is used to dissipate heat from a plurality of heat pipes (2), one end of the heat pipe (2) being inserted into the heat pipe stack core (1), and the other end of the heat pipe (2) being inserted into the heat pipe heat exchanger (4); An air cooling system, the air cooling system comprising an air channel opened in the heat pipe heat exchanger (4), the heat pipe (2) being located in the air channel, the top and bottom of the air channel being respectively provided with flow openings, and when the heat pipe heat exchanger (4) fails, the flow openings are opened to communicate with the external atmosphere; A waste heat discharge heat exchanger (3), the waste heat discharge heat exchanger (3) having an inner chamber (6) and an outer chamber (7), the inner chamber (6) and the outer chamber (7) being filled with molten metal for heat conduction, the heat pipe (2) passing through the inner chamber (6), a self-opening component being arranged between the inner chamber (6) and the outer chamber (7), when the heat pipe heat exchanger (4) fails and the temperature of the heat pipe (2) exceeds a preset temperature, the self-opening component automatically opens, so that the molten metal between the inner chamber (6) and the outer chamber (7) circulates in a self-driven manner.

2. The dual-mode self-starting residual heat removal system for a heat pipe stack according to claim 1, characterized in that: The waste heat discharge heat exchanger (3) comprises an outer shell (18), an inner ring sleeve (19) is fixedly connected to the inner shell (18), and the inner ring sleeve (19) divides the internal space of the outer shell (18) into the inner chamber (6) and the outer chamber (7), and the outer chamber (7) is arranged around the inner chamber (6).

3. The dual-mode self-starting residual heat removal system for a heat pipe stack according to claim 2, characterized in that: The self-opening component comprises a plurality of circulation channels (16) opened on an inner ring sleeve (19), the two ends of the circulation channel (16) being respectively connected to the inner chamber (6) and the outer chamber (7), a sealing plug (17) being inserted into one end of the circulation channel (16) facing the outer chamber (7), a heat-expandable component being arranged in the inner chamber (6), the heat-expandable component being connected to the sealing plug (17), and when the heat pipe exchanger (4) fails, the heat-expandable component is heated and expanded, thereby squeezing the sealing plug (17), causing the sealing plug (17) to pop out of the circulation channel (16).

4. The dual-mode self-starting residual heat removal system for a heat pipe stack according to claim 3, characterized in that: The heat-expandable component comprises an annular metal plate (15) arranged in the inner chamber (6), a gap being provided between the annular metal plate (15) and the inner ring sleeve (19), the annular metal plate (15) being arranged around the outside of the plurality of heat pipes (2), the annular metal plate (15) being provided with a plurality of through holes connected to the circulation channel (16), a plurality of push rods (24) being fixedly connected to the outer wall of the annular metal plate (15), the plurality of push rods (24) being arranged in one-to-one correspondence with the plurality of sealing plugs (17), and the end of the push rod (24) away from the annular metal plate (15) extending into the circulation channel (16) and being fixedly connected to the sealing plug (17).

5. The dual-mode self-starting residual heat removal system for a heat pipe stack according to claim 4, characterized in that: The circulation channel (16) comprises a main flow channel (161), one end of the main flow channel (161) is connected to two branch flow channels (162), the push rod (24) is located between the two branch flow channels (162), and the push rod (24) penetrates the side wall of the inner ring sleeve (19) and extends into the main flow channel (161) to be fixedly connected to the sealing plug (17).

6. The dual-mode self-starting residual heat removal system for a heat pipe stack according to claim 1, characterized in that: The air cooling system further comprises an air inlet pipe (25) and an air outlet pipe (26); the air inlet pipe (25) is fixedly connected to and communicated with the flow opening at the bottom of the air channel, and the air outlet pipe (26) is fixedly connected to and communicated with the flow opening at the top of the air channel; a first control valve (20) and a second control valve (21) are fixedly connected to the air inlet pipe (25) and the air outlet pipe (26), respectively.

7. The dual-mode self-starting residual heat removal system for a heat pipe stack according to claim 6, characterized in that: The first control valve (20) and the second control valve (21) are closed when power is on, and are opened when power is off.

8. The dual-mode self-starting residual heat removal system for a heat pipe stack according to claim 6, characterized in that: The top of the air outlet duct (26) is fixedly connected to and communicated with a chimney (8).

9. The dual-mode self-starting residual heat removal system for a heat pipe stack according to claim 2, characterized in that: A plurality of heat sinks are arranged on the outer wall of the outer shell (18).

10. The dual-mode self-starting residual heat removal system for a heat pipe stack according to claim 1, characterized in that: The heat pipe heat exchanger (4) provides a circulating cooling medium through a Brayton cycle system (5), and the Brayton cycle system (5) includes a turbine (9), a compressor (10), a generator (11), a regenerator (12), and a precooler (13); The inlet of the turbine (9) is communicated with the outlet of the cooling channel of the heat pipe heat exchanger (4), the outlet of the turbine (9) is communicated with the first inlet of the regenerator (12), the first outlet of the regenerator (12) is communicated with the inlet of the precooler (13), the outlet of the precooler (13) is communicated with the inlet of the compressor (10), the outlet of the compressor (10) is communicated with the second inlet of the regenerator (12), and the second outlet of the regenerator (12) is communicated with the inlet of the cooling channel of the heat pipe heat exchanger (4); the generator (11) is transmission-connected with the turbine (9); and a third valve (22) and a fourth valve (23) are respectively provided on the pipelines at the inlet and outlet ends of the cooling channel of the heat pipe heat exchanger (4).

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