A small pressurized water reactor

Abstract

The application provides a small-sized pressurized water reactor, relates to the technical field of nuclear power, and aims at improving the technical problem that the reactor main loop is not simplified and the equipment is not miniaturized due to the existence of a coolant pump in the prior art small-sized pressurized water reactor with forced circulation. The application comprises a pressure vessel, a reactor core, a heat exchanger, a stabilizer and a coolant driving device, wherein the coolant driving device comprises a driving rotor assembly arranged in the inside of the pressure vessel and a driven rotor assembly arranged in the outside of the pressure vessel; the driving rotor assembly comprises a driving motor and a driving rotor connected with the driving motor; the driven rotor assembly comprises a driven rotor and an impeller connected with the driven rotor; and the driving rotor is magnetically connected with the driven rotor. The application adopts the magnetic connection between the driving rotor and the driven rotor, and no corresponding connecting part is arranged on the pressure vessel, so that the safety is ensured while the equipment volume is reduced.

Description

Technical Field

[0001] This invention relates to the field of nuclear power technology, and more specifically, to a small pressurized water reactor. Background Technology

[0002] Pressurized water reactors typically use light water as a moderator and coolant. There are usually two types of driving forces for coolant flow: one is driven by a coolant pump, called forced circulation; the other relies on the density and height difference of the coolant at the heat exchanger and the reactor core to create a driving force for coolant flow, called natural circulation.

[0003] In small pressurized water reactors employing forced circulation, the presence of coolant pumps hinders the simplification of the reactor main loop and the miniaturization of equipment. Summary of the Invention

[0004] The object of the present invention includes providing a small pressurized water reactor to improve the technical problems in existing small pressurized water reactors employing forced circulation, which are not conducive to the simplification of the reactor main loop and the miniaturization of equipment due to the presence of coolant pumps.

[0005] The embodiments of the present invention can be implemented as follows: In a first aspect, the present invention provides a small pressurized water reactor, comprising a pressure vessel and a reactor core, a heat exchanger, and a pressurizer disposed within the pressure vessel, and further comprising: A coolant drive device, comprising an active rotor assembly disposed inside the pressure vessel and a driven rotor assembly disposed outside the pressure vessel; The active rotor assembly includes a drive motor and an active rotor connected to the drive motor; the driven rotor assembly includes a driven rotor and an impeller connected to the driven rotor; the active rotor and the driven rotor are magnetically connected.

[0006] In an optional embodiment, the pressure vessel includes a shell and an upper end cap and a lower end cap respectively disposed at both ends of the shell; The upper end cap, the shell, and the lower end cap respectively define a first accommodating space, a second accommodating space, and a third accommodating space in the axial direction; The pressure vessel is filled with coolant, which can flow between the first containment space, the second containment space, and the third containment space.

[0007] In an optional embodiment, the voltage regulator is disposed in the first accommodating space.

[0008] In an optional embodiment, the core and heat exchanger are disposed in the second accommodating space, and the core is disposed below the heat exchanger.

[0009] In an optional embodiment, the driven rotor assembly is disposed in the third receiving space.

[0010] In an optional embodiment, the coolant drive device further includes a support housing configured to isolate the driven rotor assembly from the coolant within the third accommodating space.

[0011] In an optional implementation, the heat exchanger is a steam generator.

[0012] In an optional embodiment, the heat exchanger is connected to a water inlet and a steam / hot water outlet, respectively; The water inlet is connected to a water supply pipe, and the steam / hot water outlet is connected to a steam pipe.

[0013] In an optional embodiment, the small pressurized water reactor further includes a containment vessel, in which the pressure vessel is housed.

[0014] In an optional embodiment, high-temperature resistant permanent magnets are provided on the active rotor and the driven rotor.

[0015] The beneficial effects of the small pressurized water reactor provided in this embodiment of the invention include: This invention provides a small pressurized water reactor comprising a pressure vessel, a core, a heat exchanger, a pressurizer, and a coolant drive unit. The coolant drive unit includes an active rotor assembly disposed inside the pressure vessel and a driven rotor assembly disposed outside the pressure vessel. The active rotor assembly includes a drive motor and an active rotor connected to the drive motor. The driven rotor assembly includes a driven rotor and an impeller connected to the driven rotor. The active rotor and the driven rotor are magnetically connected. The drive motor drives the active rotor to rotate, and the active rotor drives the driven rotor to rotate through the magnetic connection, thereby enabling the driven rotor to drive the impeller to rotate. This, in turn, drives the coolant flow within the pressure vessel through the impeller. This improves the problem of low coolant flow rate in the core due to the lack of a coolant pump, which is detrimental to heat transfer and equipment miniaturization. Because the active rotor assembly is disposed outside the pressure vessel, the equipment size is reduced. Furthermore, since the active rotor and the driven rotor are magnetically connected, there is no need to create corresponding connection points on the pressure vessel, thus ensuring safety while reducing equipment size. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of an example of a small pressurized water reactor provided by the present invention.

[0018] Icons: 100 - Pressure vessel; 110 - Shell; 120 - Upper head; 130 - Lower head; 200-Core; 300 - Heat exchanger; 310 - Feed water inlet; 320 - Steam / hot water outlet; 400- Voltage Regulator; 500 - Coolant drive unit; 510 - Drive rotor assembly; 511 - Drive motor; 512 - Drive rotor; 520 - Driven rotor assembly; 521 - Driven rotor; 522 - Impeller; 530 - Support housing; A - First containment space; B - Second containment space; C - Third containment space. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0020] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0021] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0022] In the description of this invention, it should be noted that if terms such as "upper," "lower," "inner," or "outer" are used to indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of this invention is usually placed, they are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0023] Furthermore, the terms "first" and "second" are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0024] It should be noted that, where there is no conflict, the features in the embodiments of the present invention can be combined with each other.

[0025] Pressurized water reactors typically use light water as a moderator and coolant. When the coolant flows through the reactor core, it carries away the heat generated in the fuel assemblies and transfers the heat to other loops through steam generators or heat exchangers.

[0026] There are generally two types of driving forces for coolant flow. One type is driven by coolant pumps, called forced circulation, such as vertical shaft seal pumps, canned pumps, and wet winding pumps used in large commercial pressurized water reactors. The other type relies on the density and height differences of the coolant at the heat exchanger and the reactor core to form a driving force, which causes the coolant to flow. This is called natural circulation.

[0027] Forced circulation pressurized water reactors have higher in-core flow velocities and stronger heat exchange capabilities, while natural circulation pressurized water reactors have lower coolant flow velocities and weaker heat exchange capabilities. Furthermore, a sufficient height difference is required between the reactor core and the heat exchanger, necessitating minimal fluid system resistance and resulting in lower reactor power. Natural circulation reactors, lacking rotating parts, offer better safety than forced circulation reactors.

[0028] Large commercial nuclear power plants typically employ forced circulation, with coolant pumps installed on the cold pipe section between the pressure vessel and the steam generator. For small pressurized water reactors, the reactor coolant system may use either forced circulation or natural circulation.

[0029] In small pressurized water reactors employing forced circulation, the presence of coolant pumps (e.g., shielded pumps) hinders the miniaturization of reactor equipment.

[0030] The following detailed description of the overall structure, working principle, and technical effects of the small pressurized water reactor provided by the present invention, through embodiments and in conjunction with the accompanying drawings, is a practical example.

[0031] Please see Figure 1 This embodiment provides a small pressurized water reactor, including a pressure vessel 100 and a core 200, a heat exchanger 300 and a pressurizer 400 disposed within the pressure vessel 100; the small pressurized water reactor provided in this embodiment also includes a coolant driving device 500, which is configured to drive coolant introduced into the pressure vessel 100.

[0032] When the coolant drive device 500 is in the off state, the coolant is in a natural circulation state. The flow direction of the coolant in the pressure vessel 100 is as follows: the coolant in the core 200 region is heated, which causes the coolant density in that region to decrease and thus flow upward. The coolant is cooled when passing through the heat exchanger 300, which increases the coolant density and causes it to flow downward back to the bottom of the pressure vessel 100 and be heated again by the heat exchanger 300. At this time, the coolant in the pressure vessel 100 achieves natural circulation under the action of density difference.

[0033] When the coolant drive device 500 is in the open state, the coolant is in a forced circulation state. The flow direction of the coolant in the pressure vessel 100 is as follows: the coolant in the core 200 region is heated, causing the coolant density in that region to decrease and thus flow upward. The coolant is cooled when passing through the heat exchanger 300, causing the coolant density to increase and flow downward back to the bottom of the pressure vessel 100. At this time, the coolant can be pumped to the core 200 and reheated under the action of the coolant drive device 500. After being heated, it continues to flow to the heat exchanger 300 for heat exchange. After heat exchange, the coolant in the 300 returns to the coolant drive device 500 and is driven again. At this time, the coolant in the pressure vessel 100 mainly achieves forced circulation under the action of the coolant drive device 500. Figure 1 The middle arrow indicates the flow direction of the coolant in the pressure vessel 100 under the driving action of the coolant driving device 500.

[0034] In this embodiment, the coolant drive device 500 includes an active rotor assembly 510 disposed inside the pressure vessel 100 and a driven rotor assembly 520 disposed outside the pressure vessel 100.

[0035] Furthermore, the active rotor assembly 510 includes a drive motor 511 and an active rotor 512 connected to the drive motor 511; the driven rotor assembly 520 includes a driven rotor 521 and an impeller 522 connected to the driven rotor 521; the active rotor 512 and the driven rotor 521 are magnetically connected.

[0036] In some embodiments, the active rotor 512 consists of a disc-shaped magnetic yoke and an array of permanent magnets. The magnetic yoke is made of low-carbon steel or aluminum alloy and is connected to the drive shaft of the drive motor 511. The permanent magnets (e.g., high energy product materials such as neodymium iron boron) are arranged at equal intervals along the circumference and fixed on the surface of the magnetic yoke in an alternating N-pole and S-pole manner, with the magnetization direction being axial, forming a magnetic field perpendicular to the disc surface of the active rotor 512. The structure of the driven rotor 521 is completely symmetrical to that of the active rotor 512. The driven rotor also includes a disc-shaped magnetic yoke and an array of permanent magnets, with the permanent magnets arranged in opposite polarities to those of the active rotor 512, thereby ensuring mutual attraction and coupling of the magnetic fields.

[0037] In this embodiment, the active rotor 512 and the driven rotor 521 are spaced apart on the outer and inner sides of the pressure vessel 100. When the active rotor 512 rotates under the drive of the drive motor 511, its permanent magnet generates a rotating magnetic field. This magnetic field passes through the pressure vessel 100 and interacts with the permanent magnet of the driven rotor 521, generating a driving force that causes the driven rotor 521 to rotate synchronously, thereby enabling the driven rotor 521 to drive the impeller 522 to rotate.

[0038] In the small pressurized water reactor provided in this embodiment, the active rotor assembly 510 is located outside the pressure vessel 100, thereby reducing the size of the equipment. At the same time, since the active rotor 512 and the driven rotor 521 are magnetically connected, there is no need to open corresponding connection parts (e.g., openings) on the pressure vessel 100, thereby ensuring the safety of the equipment while reducing the size of the equipment.

[0039] In addition, in the event of a power outage, the impeller 522 inside the pressure vessel 100 continues to rotate due to its rotational inertia, which helps to establish a natural circulation.

[0040] In some embodiments, the coolant drive device 500 further includes a support housing 530, and both the support housing 530 and the driven rotor assembly 520 are disposed in the third receiving space C; wherein the support housing 530 is configured to isolate the driven rotor assembly 520 from the coolant in the third receiving space C; the impeller 522 can penetrate the support housing 530 and act on the coolant under the drive of the driven rotor 521.

[0041] Please continue to participate. Figure 1 Furthermore, in this embodiment, the pressure vessel 100 includes a shell 110 and an upper end cap 120 and a lower end cap 130 respectively disposed at both ends of the shell 110; wherein, the upper end cap 120, the shell 110 and the lower end cap 130 sequentially define a first accommodating space A, a second accommodating space B and a third accommodating space C in the axial direction; a coolant is introduced into the pressure vessel 100, and the coolant can flow between the first accommodating space A, the second accommodating space B and the third accommodating space C.

[0042] It is understood that the small pressurized water reactor provided in this embodiment should also include a main pump for pumping coolant into the pressure vessel 100. The coolant (e.g., high-pressure water) is driven by the main pump and enters the pressurized water reactor pressure vessel 100 through the inlet nozzle of the pressure vessel 100.

[0043] The specific flow direction of the coolant within the pressure vessel 100 is as follows: the coolant in the core 200 region is heated (at this time, it is in the second containment space B), causing the coolant density in this region to decrease and thus flow upward. The coolant is cooled when passing through the heat exchanger 300 (at this time, it is in the second containment space B), causing the coolant density to increase and flow downward back to the bottom of the pressure vessel 100 (at this time, it is in the third containment space C). At this time, the coolant can be pumped to the core 200 and reheated under the action of the coolant drive device 500 (at this time, it is in the second containment space B). After heating, it continues to flow to the heat exchanger 300 for heat exchange (at this time, it is in the second containment space B). After heat exchange, the coolant in 300 returns to the coolant drive device 500 and is driven again (at this time, it returns to the third containment space C).

[0044] In this embodiment, the reactor core 200 and the heat exchanger 300 are disposed in the second accommodating space B, and the reactor core 200 is disposed below the heat exchanger 300, so that the coolant can achieve natural circulation under the action of density difference in natural circulation state.

[0045] Furthermore, the heat exchanger 300 is a steam generator, and is connected to a water inlet 310 and a steam / hot water outlet 320, wherein the water inlet 310 is connected to a water supply pipe, and the steam / hot water outlet 320 is connected to a steam pipe.

[0046] Similar to existing technologies, the working principle of a steam generator is as follows: the high-temperature and high-pressure coolant in the primary loop flows through the heat transfer tube bundle and transfers heat to the secondary loop feedwater (which enters the shell through the feedwater inlet 310 via the feedwater pipe) outside the tube bundle. After absorbing heat, the feedwater vaporizes to form saturated steam. After the steam-water separator removes moisture and improves the steam quality, it is transported from the steam / hot water outlet 320 to the steam turbine for power generation through the steam pipe. The primary loop coolant releases heat and its temperature decreases, so it is returned to the reactor for recycling. Throughout the process, the primary and secondary loop working fluids are completely isolated to ensure safety and heat exchange efficiency.

[0047] The small pressurized water reactor provided in this embodiment also includes a containment vessel, in which a pressure vessel 100 is housed.

[0048] In some embodiments, the containment vessel is cylindrical or spherical in shape. Its working principle is to isolate the reactor from the outside world during normal operation to prevent the leakage of radioactive materials. In the event of an accident, it can withstand high temperature and high pressure, and the pressure can be controlled by a spray system to cool down and depressurize, and a pressure relief valve to release pressure.

[0049] The small pressurized water reactor provided in this embodiment can achieve at least the following technical effects: By incorporating a coolant drive device 500, the active rotor assembly 510 and the driven rotor assembly 520 are located on the inner and outer sides of the lower head 130, respectively. This increases the flow rate of the core coolant without compromising the integrity of the lower head 130, thereby enhancing the reactor core heat exchange capacity.

[0050] The higher core coolant flow rate allows for the use of smaller in-core heat exchangers / steam generators and enables a smaller pressure vessel 100.

[0051] In addition, in the event of a power outage, the impeller 522 inside the pressure vessel 100 continues to rotate due to its rotational inertia, which helps to establish a natural circulation.

[0052] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A small pressurized water reactor, comprising a pressure vessel (100) and a reactor core (200), a heat exchanger (300), and a pressurizer (400) disposed within the pressure vessel (100), characterized in that, Also includes: A coolant drive device (500) includes an active rotor assembly (510) disposed inside the pressure vessel (100) and a driven rotor assembly (520) disposed outside the pressure vessel (100). The active rotor assembly (510) includes a drive motor (511) and an active rotor (512) connected to the drive motor (511); the driven rotor assembly (520) includes a driven rotor (521) and an impeller (522) connected to the driven rotor (521); the active rotor (512) and the driven rotor (521) are magnetically connected.

2. The small pressurized water reactor according to claim 1, characterized in that, The pressure vessel (100) includes a shell (110) and an upper end cap (120) and a lower end cap (130) respectively disposed at both ends of the shell (110). The upper end cap (120), the shell (110) and the lower end cap (130) define a first accommodating space (A), a second accommodating space (B) and a third accommodating space (C) respectively in the axial direction. The pressure vessel (100) is filled with coolant, which can flow between the first containment space (A), the second containment space (B) and the third containment space (C).

3. The small pressurized water reactor according to claim 2, characterized in that, The voltage regulator (400) is disposed in the first accommodating space (A).

4. The small pressurized water reactor according to claim 2, characterized in that, The core (200) and the heat exchanger (300) are disposed in the second accommodating space (B), and the core (200) is disposed below the heat exchanger (300).

5. The small pressurized water reactor according to claim 2, characterized in that, The driven rotor assembly (520) is disposed in the third receiving space (C).

6. The small pressurized water reactor according to claim 2, characterized in that, The coolant drive device (500) also includes a support housing (530) configured to isolate the driven rotor assembly (520) from the coolant within the third containment space (C).

7. The small pressurized water reactor according to claim 1, characterized in that, The heat exchanger (300) is a steam generator.

8. The small pressurized water reactor according to claim 1, characterized in that, The heat exchanger (300) is connected to a water inlet (310) and a steam / hot water outlet (320). The water inlet (310) is connected to a water supply pipe, and the steam / hot water outlet (320) is connected to a steam pipe.

9. The small pressurized water reactor according to claim 1, characterized in that, The small pressurized water reactor also includes a containment vessel, in which the pressure vessel (100) is housed.

10. The small pressurized water reactor according to claim 1, characterized in that, High-temperature resistant permanent magnets are provided on the active rotor (512) and the driven rotor (521).

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