Flash-driven natural circulation nuclear heat supply reactor

Abstract

The application provides a flash evaporation driven natural circulation nuclear heat supply reactor and belongs to the field of nuclear reactors. The problem of large-scale oscillation caused by flash evaporation and the problem of the need of power for discharging residual heat of a complex reactor structure are solved. The reactor comprises a reactor vessel, a reactor core, a supporting seat, a control rod and a driving mechanism thereof, a thermal rising partition plate, a turbulence assembly, a liquid zone heat exchanger, a gas zone heat exchanger and a non-powered gas cooling residual heat discharge system, the reactor core is connected to the inner bottom wall of the reactor vessel through the supporting seat, the thermal rising partition plate divides the reactor vessel into an ascending channel in the thermal rising partition plate and a descending channel between the thermal rising partition plate and the wall surface of the reactor vessel, the gas zone heat exchanger is arranged above the inner portion of the reactor vessel, the non-powered gas cooling residual heat discharge system is connected to the side wall of the reactor vessel and is used for carrying out the decay heat of the reactor core after the reactor core is stopped, the reactor vessel contains cooling liquid, and the turbulence assembly is used for dividing the thermal rising partition plate into multiple flow channels. The reactor is mainly used for heat dissipation of the reactor.

Description

Technical Field

[0001] This invention belongs to the field of nuclear reactors, and in particular relates to a flash-driven natural circulation nuclear heating reactor. Background Technology

[0002] In recent decades, there have been many designs for heating reactors, such as the shell-type integrated natural circulation pressurized water reactor ATS-500, the Canadian SLOW POKE natural circulation pool heating reactor, and the Swedish Agesa. However, their economic efficiency and safety have not been widely recognized, and they have problems such as complex structures.

[0003] Most existing heating reactors employ natural circulation designs. However, the driving force and heat-carrying capacity of natural circulation are limited. When the core power is high, single-phase natural circulation alone is insufficient to remove the heat generated in the core. Therefore, methods such as reducing reactor power or increasing the height difference between the hot and cold sections within the reactor are often used to improve the reactor's natural circulation capability. These methods, on the one hand, limit the reactor power level and restrict the reactor's application requirements; on the other hand, they increase the reactor's structural size, which is detrimental to reactor miniaturization.

[0004] When the coolant in the reactor approaches saturation temperature, flashing can occur due to pressure reduction. Flashing can effectively enhance the driving force of natural circulation and increase the flow rate of the primary coolant loop, but it can also cause large-scale oscillations, which is detrimental to the operation of a nuclear heating reactor. Summary of the Invention

[0005] In view of this, the present invention aims to propose a flash-driven natural circulation nuclear heating reactor to solve the problems of large-amplitude oscillations caused by flashing and the need for power to discharge waste heat due to the complex reactor structure.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: a flash-driven natural circulation nuclear heating reactor, comprising a reactor vessel, a core, a support base, control rods and their driving mechanisms, a heat rise baffle, a turbulence assembly, a liquid zone heat exchanger, a gas zone heat exchanger, and a passive gas-cooled residual heat removal system. The core is connected to the inner bottom wall of the reactor vessel via the support base. A heat rise baffle is provided at the upper end of the support base. The core, liquid zone heat exchanger, and turbulence assembly are arranged sequentially from bottom to top within the heat rise baffle. The heat rise baffle vents the reactor vessel... The reactor vessel is divided into an ascending channel within the heat-rising baffle and a descending channel between the heat-rising baffle and the reactor vessel wall. The outlet and inlet ends of the ascending channel are connected to the descending channel. A gas zone heat exchanger is installed above the interior of the reactor vessel. The control rods and their drive mechanisms are located at the top of the reactor vessel for stopping the reactor core. The passive gas-cooled residual heat removal system is connected to the side wall of the reactor vessel for removing the core decay heat after stopping the reactor core. The reactor vessel contains coolant. The turbulence assembly is used to divide the heat-rising baffle into multiple flow channels.

[0007] Furthermore, the support base includes a core confining tube, a support plate, and a support assembly. The core confining tube is disposed on the upper end surface of the support plate, and the support assembly is disposed on the lower end surface of the support plate. The support assembly is connected to the bottom wall of the reactor vessel. The reactor core is connected to the upper end of the support plate and housed within the core confining tube. The upper opening of the core confining tube is connected to the heat rise baffle.

[0008] Furthermore, a safety valve is installed on the top wall of the reactor vessel.

[0009] Furthermore, the passive gas-cooled waste heat removal system includes an inlet pipeline, an outlet pipeline, an inlet header, an outlet header, an outer pipeline, a normally closed valve, an exhaust chimney, and an inner pipeline. The inlet header and the outlet header are both connected to the inner wall of the reactor vessel. The outlet end of the inlet header is connected to the inner pipeline, and the inlet end of the outlet header is connected to the outer pipeline. The inner pipeline is housed within the outer pipeline. The outlet end of the outlet header is connected to one end of the outlet pipeline, and the other end of the outlet pipeline is connected to the exhaust chimney. The inlet end of the inlet header is connected to the inlet pipeline located outside the reactor vessel. A normally closed valve that opens when the reactor core is stopped is installed in the inlet pipeline.

[0010] Furthermore, an air purification filter is installed inside the air outlet pipeline.

[0011] Furthermore, an air purification filter is installed inside the intake pipeline, between the normally closed air valve and the inlet manifold.

[0012] Furthermore, the lower half of the reactor vessel is set within a concrete foundation, and the height of the passive gas-cooled waste heat removal system is higher than the upper surface of the concrete foundation.

[0013] Furthermore, the turbulence assembly includes multiple turbulence plates that divide the heat rise baffle into multiple flow channels, with at least one turbulence device disposed in each flow channel.

[0014] Furthermore, the coolant level is lower than the lower edge of the gas zone heat exchanger.

[0015] Furthermore, the heat-raising baffle is a vertically arranged tubular structure with its diameter gradually narrowing from bottom to top.

[0016] Compared with the prior art, the beneficial effects of the present invention are:

[0017] 1. This reactor adopts a fully natural circulation system, eliminating the need for a main pump, simplifying the structure, and improving inherent safety. During normal operation, the coolant uses the reactor core as a heat source and the liquid zone heat exchanger as a heat sink to form a temperature difference between the hot and cold cores, driving natural circulation. The coolant undergoes flash evaporation in the rising channel, thereby increasing the driving force. Meanwhile, the turbulence-disrupting components divide the flow channels in the rising channel, eliminating the oscillations caused by flash evaporation and avoiding component damage caused by oscillations.

[0018] 2. This reactor adopts an atmospheric pressure design inside the reactor vessel, which reduces the pressure on the primary circuit pressure boundary compared to a pressurized water reactor, thereby reducing the possibility of rupture accidents and coolant leakage accidents and improving inherent safety. At the same time, atmospheric pressure simplifies the design of various systems and pipelines and makes the site selection of heating plants more convenient.

[0019] 3. This reactor is equipped with a variety of safety measures, such as gas zone heat exchangers, safety valves, and passive safety systems. The gas zone heat exchanger can discharge the heat carried by the steam accumulated at the upper head of the reactor into the reactor, thereby reducing the pressure on the reactor vessel in a timely manner. The safety valve is normally closed, but can be opened when the heat and pressure in the upper part of the reactor vessel exceed a certain value, or when the gas zone heat exchanger fails and cannot discharge heat, so as to release pressure in a timely manner and prevent more serious accidents from occurring. The passive safety system can be activated in the event of a shutdown or accident, and does not rely on external power. It can limit the severity of an accident and buy time for subsequent accident handling. Attached Figure Description

[0020] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0021] Figure 1 This is a schematic diagram of the structure of a flash-driven natural circulation nuclear heating reactor according to the present invention.

[0022] Figure 2 This is a schematic diagram of the first structural form of the heat-rising partition described in this invention;

[0023] Figure 3 This is a schematic diagram of the second structural form of the heat-rising partition described in this invention;

[0024] Figure 4 This is a schematic diagram of the third structural form of the heat-rising partition described in this invention;

[0025] Figure 5 This is a schematic diagram of the first structural form of the turbulence component described in this invention;

[0026] Figure 6 This is a schematic diagram of the second structural form of the turbulence component described in this invention;

[0027] Figure 7 This is a schematic diagram of the third structural form of the turbulence component described in this invention;

[0028] Figure 8 This is a schematic diagram of the fourth structural form of the turbulence component described in this invention;

[0029] Figure 9 This is a schematic diagram of the passive air-cooled waste heat removal system described in this invention.

[0030] Reactor vessel 1; Core 2; Core enclosure 3; Support plate 4; Support assembly 5; Control rod and its drive mechanism 6; Heat rise baffle 7; Turbine assembly 8; Liquid zone heat exchanger 9; Gas zone heat exchanger 10; Safety valve 11; Inlet pipeline 12; Outlet pipeline 13; Inlet header 14; Outlet header 15; External pipeline 16; Normally closed valve 17; Exhaust chimney 18; Air purification filter 19; Concrete foundation 20; Internal pipeline 21; Baffle 22; Turbine 23. Detailed Implementation

[0031] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of the present invention can be combined with each other, and the described embodiments are only some embodiments of the present invention, not all embodiments. Specific implementation method one:

[0033] Referring to the accompanying drawings, this embodiment describes a flash-driven natural circulation nuclear heating reactor, characterized by comprising a reactor vessel 1, a core 2, a support base, control rods and their drive mechanisms 6, a heat rise baffle 7, a turbulence assembly 8, a liquid zone heat exchanger 9, a gas zone heat exchanger 10, and a passive gas-cooled residual heat removal system. The core 2 is connected to the inner bottom wall of the reactor vessel 1 via the support base. The upper end of the support base is provided with a heat rise baffle 7. The core 2, the liquid zone heat exchanger 9, and the turbulence assembly 8 are arranged sequentially from bottom to top within the heat rise baffle 7. The heat rise baffle 7 divides the interior of the reactor vessel 1 into rising channels within the heat rise baffle 7. The reactor vessel 1 includes a descending channel between the heat riser baffle 7 and the reactor vessel 1 wall. Both the outlet and inlet ends of the ascending channel are connected to the descending channel. A gas zone heat exchanger 10 is installed above the interior of the reactor vessel 1. Control rods and their drive mechanisms 6 are located at the top of the reactor vessel 1 to stop the core 2. A passive gas-cooled residual heat removal system is connected to the side wall of the reactor vessel 1 to remove the decay heat of the core 2 after it has been stopped. The reactor vessel 1 contains coolant. The turbulence assembly 8 divides the heat riser baffle 7 into multiple channels. This division effectively reduces the oscillation effect caused by flashing. The gas zone heat exchanger 10 can remove the heat carried by the steam accumulated at the upper head of the reactor, thus reducing the pressure on the reactor vessel. The power of the gas zone heat exchanger 10 can be adjusted as needed to control the pressure and flashing degree of the gas zone.

[0034] In this embodiment, the support base includes a core confining cylinder 3, a support plate 4, and a support assembly 5. The core confining cylinder 3 is disposed on the upper end surface of the support plate 4, and the support assembly 5 is disposed on the lower end surface of the support plate 4. The support assembly 5 is connected to the bottom wall of the reactor vessel 1. The reactor core 2 is connected to the upper end of the support plate 4 and housed within the core confining cylinder 3. The upper opening of the core confining cylinder 3 is connected to the heat rise baffle 7. The support assembly 5 adopts an existing support structure, which is prior art and will not be described in detail here.

[0035] In this embodiment, a safety valve 11 is provided on the top wall of the reactor vessel 1. The safety valve 11 can be opened when the heat and pressure in the upper part of the reactor vessel exceed a certain value, or when the gas zone heat exchanger 10 fails and cannot dissipate heat, so as to release pressure in time and prevent more serious accidents from occurring.

[0036] In this embodiment, the passive gas-cooled waste heat removal system includes an inlet pipeline 12, an outlet pipeline 13, an inlet header 14, an outlet header 15, an outer pipeline 16, a normally closed valve 17, an exhaust chimney 18, and an inner pipeline 21. The inlet header 14 and the outlet header 15 are both connected to the inner wall of the reactor vessel 1. The outlet end of the inlet header 14 is connected to the inner pipeline 21, and the inlet end of the outlet header 15 is connected to the outer pipeline 16. The inner pipeline... Line 21 is housed within the outer pipeline 16. The outlet end of the outlet header 15 is connected to one end of the exhaust pipeline 13, and the other end of the exhaust pipeline 13 is connected to the exhaust chimney 18. The inlet end of the inlet header 14 is connected to the intake pipeline 12 located outside the reactor vessel 1. The intake pipeline 12 is equipped with a normally closed valve 17 that opens when the reactor core 2 is stopped. The outlet end of the inner pipeline 21 is below the coolant level and is not sealed. The outer pipeline 16 is immersed in the coolant. In the event of a reactor shutdown or accident, the normally closed air valve 17 opens. At this time, the air in the outer pipeline 16 is heated, rises, and enters the exhaust stack 18 through the outlet header 15. Meanwhile, the cold air in the inlet pipeline 12 is drawn into the inner pipeline 21 through the inlet header 14, descends through the inner pipeline 21, and enters the outer pipeline 16, where it is heated by the coolant. This allows the passive gas-cooled waste heat removal system to operate normally until the normally closed air valve 17 is closed again. The entire cycle continuously removes heat without requiring additional power components. Enhanced heat transfer measures, such as longitudinal vortex generators or fins, can be implemented or installed on the outer pipeline 16.

[0037] In this embodiment, an air purification filter 19 is installed inside the outlet pipeline 13. In this embodiment, an air purification filter 19 is installed inside the inlet pipeline 12, between the normally closed valve 17 and the inlet manifold 14. The air purification filter 19 can purify the gas. The air purification filter 19 uses existing filters and is existing technology, which will not be described in detail here.

[0038] In this embodiment, the lower half of the reactor vessel 1 is located within a concrete foundation 20, and the height of the passive gas-cooled waste heat removal system is higher than the height of the upper surface of the concrete foundation 20.

[0039] In this embodiment, the flow-dispersing assembly 8 includes multiple flow-dispersing plates 22, which divide the heat rise baffle 7 into multiple flow channels. At least one flow-dispersing device 23 is disposed within each flow channel. The flow channels formed by the flow-dispersing plates 22, and the flow-dispersing device 23 within each flow channel, eliminate the oscillations caused by flash evaporation. Firstly, by dividing the flow channels, the flash evaporation effect can be diverted; then, the oscillations are reduced by the flow-dispersing device 23 within each flow channel.

[0040] Preferably, there are two baffles 22, which divide the heat rise baffle 7 into four flow channels in a cross shape. Each flow channel is equipped with a baffle 23 to reduce the oscillation caused by the flash evaporation effect.

[0041] In this embodiment, the coolant level is lower than the lower edge of the gas zone heat exchanger 10. This facilitates the normal operation of the gas zone heat exchanger 10 and its ability to remove heat.

[0042] In this embodiment, the heat rise baffle 7 is a vertically arranged tubular tube with its diameter gradually narrowing from bottom to top, forming an overall truncated cone shape. This enhances the driving force of natural circulation brought about by the flash evaporation effect, increases the flow rate of the loop coolant, and, in conjunction with the turbulence-reducing component 8, reduces the oscillation effect caused by the flash evaporation effect.

[0043] During operation, when the reactor is running normally, the coolant in core 2 is heated by core 2, its temperature increases and its density decreases, causing it to flow upwards. Flashing occurs in the rising channel isolated by the heat riser 7. The coolant first undergoes heat exchange in the liquid zone heat exchanger 9, and then passes through the turbulence assembly 8 to eliminate the oscillations caused by flashing. Subsequently, the coolant enters the descending channel and returns to the support assembly 5, flowing back into core 2 from below the support assembly 5 to be heated again, and then repeating the above process to complete the coolant circulation.

[0044] During the flash evaporation process, a large amount of steam is generated. Some of this steam rises above the coolant surface and exchanges heat with the gas-zone heat exchanger 10. If the amount of steam or heat is too large, exceeding a certain limit or posing an accident risk, the safety valve 11 will be opened to release pressure.

[0045] During a shutdown under normal or accident conditions, the control rods and their drive mechanism 6 extend vertically downwards into the reactor core 2 to introduce negative reactivity and initiate the shutdown process. At this time, the passive gas-cooled residual heat removal system is activated.

[0046] Specifically, the normally closed valve 17 will open due to pressure. At this time, the air in the outer pipeline 16 is in a heated state. The hot air rises and enters the exhaust chimney 18 through the outlet manifold 15. Meanwhile, the cold air in the intake pipeline 12 will be drawn into the inner pipeline 21 through the inlet manifold 14, and then descend through the inner pipeline 21 into the outer pipeline 16, where it will be heated by the coolant. Thus, the passive air-cooled waste heat discharge system operates normally until the normally closed valve 17 is closed again. The entire cycle will continuously remove heat without the need for additional power components. Specific Implementation Method Two:

[0048] The only difference between this embodiment and Specific Implementation Method 1 is that the heat-raising baffle 7 is a tube that narrows in the middle and has the same width at the inlet and outlet ends, which can expand the heat exchange area at the outlet end and help the coolant cool down. Specific implementation method three:

[0050] The only difference between this embodiment and Specific Implementation Method 1 is that the outer wall of the heat-raising baffle 7 is curved, which helps to reduce resistance and enhance the fluid dynamics brought about by the flash evaporation effect. Specific implementation method four:

[0052] The only difference between this embodiment and the first specific implementation method is that: the number of the baffles 22 is four and they are connected in a circumferentially distributed manner inside the heat rise baffle 7 to divide the heat rise baffle 7 into eight flow channels. Each flow channel is provided with a baffle 23. This method can further reduce the oscillation effect without affecting the flow dynamics brought about by the flash evaporation effect. Specific implementation method five:

[0054] The only difference between this embodiment and Specific Implementation Method 1 is that: the spoiler 22 is configured as four straight spoilers and one annular spoiler. The four straight spoilers are evenly distributed around the circumference and connected to the outer ring surface of the annular spoiler. Each straight spoiler is provided with a spoiler 23. Multiple spoilers 23 are evenly distributed around the circumference of the inner ring surface of the annular spoiler. The axis of the annular spoiler coincides with the axis of the heat rise baffle 7, which can further reduce the oscillation effect without affecting the flow dynamics brought about by the flash evaporation effect. Specific implementation method six:

[0056] The only difference between this embodiment and the first specific implementation method is that: the baffle plate 22 is provided with four baffles arranged in a grid pattern to divide the heat rise baffle plate 7 into nine flow channels. Four baffles 23 are provided in the square flow channel in the middle flow channel, and two baffles 23 are provided in each flow channel around the perimeter. This can further reduce the oscillation effect without affecting the flow dynamics brought about by the flash evaporation effect.

[0057] The embodiments of the present invention disclosed above are merely illustrative of the invention. These embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention.

Claims

1. A flash-driven, natural circulation nuclear heating reactor, characterized in that: The reactor vessel includes a reactor vessel (1), a reactor core (2), a support base, control rods and their drive mechanisms (6), a heat riser baffle (7), a turbulence assembly (8), a liquid zone heat exchanger (9), a gas zone heat exchanger (10), and a passive gas-cooled waste heat removal system. The reactor core (2) is connected to the inner bottom wall of the reactor vessel (1) via the support base. The upper end of the support base is provided with a heat riser baffle (7). The reactor core (2), the liquid zone heat exchanger (9), and the turbulence assembly (8) are arranged sequentially from bottom to top within the heat riser baffle (7). The heat riser baffle (7) divides the interior of the reactor vessel (1) into rising channels within the heat riser baffle (7). The heat riser (7) and the descending channel between the heat riser (7) and the reactor vessel (1) wall are connected to the descending channel at both the outlet and inlet ends. A gas zone heat exchanger (10) is provided above the inside of the reactor vessel (1). The control rod and its drive mechanism (6) are provided at the top of the reactor vessel (1) to stop the reactor core (2). The passive gas-cooled residual heat removal system is connected to the side wall of the reactor vessel (1) to remove the decay heat of the reactor core (2) after stopping the reactor core (2). The reactor vessel (1) is filled with coolant. The turbulence assembly (8) is used to divide the inside of the heat riser (7) into multiple flow channels. The passive gas-cooled waste heat removal system includes an inlet pipeline (12), an outlet pipeline (13), an inlet header (14), an outlet header (15), an external pipeline (16), a normally closed valve (17), an exhaust chimney (18), and an internal pipeline (21). The inlet header (14) and the outlet header (15) are both connected to the inner wall of the reactor vessel (1). The outlet end of the inlet header (14) is connected to the internal pipeline (21), and the inlet of the outlet header (15) is connected to the internal pipeline (21). The inner pipeline (21) is housed within the outer pipeline (16), the outlet end of the outlet header (15) is connected to one end of the gas outlet pipeline (13), the other end of the gas outlet pipeline (13) is connected to the exhaust chimney (18), the inlet end of the inlet header (14) is connected to the gas inlet pipeline (12) located outside the reactor vessel (1), and the gas inlet pipeline (12) is equipped with a normally closed gas valve (17) that is opened when the reactor core (2) is stopped. The turbulence assembly (8) includes a plurality of turbulence plates (22), which divide the heat rise partition (7) into a plurality of flow channels, and at least one turbulence device (23) is provided in each flow channel. The coolant level is lower than the lower edge of the gas zone heat exchanger (10); The heat riser baffle (7) is a vertically arranged tubular tube with a diameter that gradually narrows from bottom to top.

2. The flash-driven natural circulation nuclear heating reactor according to claim 1, characterized in that: The support base includes a core confining tube (3), a support plate (4), and a support assembly (5). The core confining tube (3) is disposed on the upper end surface of the support plate (4), and the support assembly (5) is disposed on the lower end surface of the support plate (4). The support assembly (5) is connected to the bottom wall of the reactor vessel (1). The core (2) is connected to the upper end of the support plate (4) and housed in the core confining tube (3). The upper opening of the core confining tube (3) is connected to the heat rise baffle (7).

3. A flash-driven natural circulation nuclear heating reactor according to claim 1, characterized in that: A safety valve (11) is installed on the top wall of the reactor vessel (1).

4. A flash-driven natural circulation nuclear heating reactor according to claim 3, characterized in that: An air purification filter (19) is installed inside the air outlet pipeline (13).

5. A flash-driven natural circulation nuclear heating reactor according to claim 4, characterized in that: An air purification filter (19) is installed inside the air intake pipeline (12) and between the normally closed air valve (17) and the inlet manifold (14).

6. A flash-driven natural circulation nuclear heating reactor according to claim 1, characterized in that: The lower half of the reactor vessel (1) is set inside the concrete foundation (20), and the height of the passive gas-cooled waste heat discharge system is higher than the height of the upper surface of the concrete foundation (20).

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