Self-driven water replenishing system and method for water pool where reactor body is located

Abstract

The application discloses a self-driven water supplement system and method for a reactor pool, and belongs to the field of nuclear power engineering. The self-driven water supplement system comprises a reactor pool, a reactor container, a main cooling mechanism, a passive cooling mechanism and a monitoring mechanism. The reactor container is arranged in the reactor pool. The main cooling mechanism is in heat exchange connection with the reactor container. The passive cooling mechanism comprises a screw expander, a circulating water pump and a cooling pool. The power input end of the screw expander is connected with the inside of the reactor pool. The power output end of the screw expander is connected with the power input end of the circulating water pump. The water pumping end of the circulating water pump is connected with the inside of the cooling pool. The water supply end of the circulating water pump is connected with the inside of the reactor pool. The main control valve of the monitoring mechanism is connected with the power input end of the screw expander. When the pressure or water level in the reactor pool exceeds the preset value, the monitoring mechanism is used for controlling the main control valve to be opened, so that the automatic water supplement into the reactor pool is realized.

Description

Technical Field

[0001] This invention relates to the technical field of reactor cooling systems, and particularly to a self-driven water replenishment system and method for the water pool where the reactor body is located. Background Technology

[0002] In existing pool-type or shell-and-pool reactors, the reactor core and its containment vessel are immersed in a large pool of water. During normal operation, the reactor transfers the heat from the fission reaction to end users through heat transfer loops and heat exchangers. When the reactor is shut down normally or due to an accident, the pool submerged in the reactor will serve to remove residual heat from the reactor core. As the core decay heat is continuously released into the pool, its water temperature will continuously rise and eventually reach a boiling state.

[0003] In existing technical solutions, additional cooling measures are generally adopted to avoid reactor overheating. However, these measures only consider using natural forces or electrically driven circulating cooling loops formed by factors such as temperature difference and height difference to cool the water pool. They do not consider the situation where the above factors fail or the external heat sink is lost, causing the water pool to overheat and boil, resulting in a drop in the water level. If the water pool is not replenished in time, the reactor decay heat discharge will fail, leading to serious consequences such as core meltdown.

[0004] In other words, existing technologies do not take all factors into account and are prone to failure, so there is an urgent need for a technical solution that can solve this problem. Summary of the Invention

[0005] The purpose of this invention is to provide a self-driven water replenishment system and method for the water pool where the reactor body is located, so as to solve the problem that the prior art is prone to failure.

[0006] To address the aforementioned technical problems, this invention provides a self-driven makeup water system for the reactor body's reservoir, comprising a reactor reservoir, a reactor vessel, an active cooling mechanism, a passive cooling mechanism, and a monitoring mechanism; the reactor reservoir is enclosed as a sealed space; the reactor vessel is located within the reactor reservoir, and a heat exchange pipeline is externally connected to the reactor vessel; the active cooling mechanism is heat-exchange connected to the reactor vessel; the passive cooling mechanism includes a screw expander, a circulating water pump, and a cooling water reservoir; the power input end of the screw expander is connected to the interior of the reactor reservoir, and the screw expander's... The power output end is connected to the power input end of the circulating water pump, and the vent of the screw expander is connected to a waste steam discharge pipeline; the pumping end of the circulating water pump is connected to the interior of the cooling water pool, and the supply end of the circulating water pump is connected to the interior of the reactor pool; the monitoring mechanism includes a pressure sensor, a water level sensor, and a main control valve; the pressure sensor and the water level sensor are both located inside the reactor pool; the main control valve is connected to the power input end of the screw expander; when the pressure or water level in the reactor pool exceeds a preset value, the monitoring mechanism controls the main control valve to open.

[0007] In one embodiment, the self-driven makeup water system further includes a backup cooling mechanism, which includes a backup screw expander and a backup circulating water pump. The power input end of the backup screw expander is connected to the interior of the reactor pool, and the power output end of the backup screw expander is connected to the power input end of the backup circulating water pump. The vent of the backup screw expander is connected to a backup exhaust steam discharge pipeline. The pumping end of the backup circulating water pump is connected to the interior of the cooling water pool, and the supply end of the backup circulating water pump is connected to the interior of the reactor pool. The monitoring mechanism is also used to control the opening and closing of the backup screw expander and the reactor pool.

[0008] In one embodiment, the monitoring mechanism further includes a backup passage valve and a water flow sensor; the backup passage valve is connected to the power input terminal of the backup screw expander; the water flow sensor is located at the outlet of the circulating water pump in the reactor pool; when the water supply of the circulating water pump is measured to be lower than a preset value, the monitoring mechanism is used to control the backup passage valve to open.

[0009] In one embodiment, the backup cooling mechanism further includes a backup water tank, and the pumping end of the backup circulating water pump is connected to the interior of the backup water tank.

[0010] In one embodiment, when the water supply of the circulating water pump is measured to be lower than a preset value, the monitoring mechanism is also used to control the main control valve to close.

[0011] In one embodiment, when the water supply of the circulating water pump is measured to be normal and the water level in the reactor pool is lower than a preset value, the monitoring mechanism is used to control the main control valve and the backup passage valve to open.

[0012] In one embodiment, an emergency valve is connected to the pipeline through which the active cooling mechanism exchanges heat with the reactor vessel. Closing the emergency valve is used to cut off the heat exchange between the active cooling mechanism and the reactor vessel. The heat exchange pipeline is connected to the active cooling mechanism, and a heat exchange valve is connected to the heat exchange pipeline. The heat exchange valve is used to control the opening and closing of the active cooling mechanism and the heat exchange pipeline.

[0013] In one embodiment, the active cooling mechanism includes a first circulating heat exchange loop, a second circulating heat exchange loop, a third circulating heat exchange loop, a first heat exchanger, a second heat exchanger, and a heat-using terminal; the first circulating heat exchange loop is connected between the first heat exchanger and the reactor vessel, the first circulating heat exchange loop is connected to the emergency valve, and the first circulating heat exchange loop is also connected to the heat exchange pipeline; the second circulating heat exchange loop is connected between the first heat exchanger and the second heat exchanger; the third circulating heat exchange loop is connected between the second heat exchanger and the heat-using terminal.

[0014] In one embodiment, the exhaust steam venting pipeline is located inside the building where the reactor vessel is housed.

[0015] To address the aforementioned technical problems, this invention also provides a self-driven water replenishment method for the reactor vessel's water pool. This method utilizes the aforementioned self-driven water replenishment system, where the active cooling mechanism actively cools and dissipates heat from the reactor vessel. When the reactor is shut down or an accident occurs, the active cooling mechanism is shut down, and the heat exchange pipeline is opened to exchange heat with the water in the reactor water pool. If the pressure or water level in the reactor water pool exceeds a preset value, the monitoring mechanism controls the main control valve to open. The steam generated in the reactor water pool drives the screw expander to operate, and the screw expander drives the circulating water pump to operate, drawing water from the cooling water pool to the reactor water pool.

[0016] The beneficial effects of this invention are as follows:

[0017] Since the power input end of the screw expander is connected to the interior of the reactor pool, the power output end of the screw expander is connected to the power input end of the circulating water pump, the pumping end of the circulating water pump is connected to the interior of the cooling water pool, the supply end of the circulating water pump is connected to the interior of the reactor pool, and the main control valve is connected to the power input end of the screw expander, when the pressure or water level in the reactor pool exceeds the preset value, the monitoring mechanism controls the main control valve to open, thereby enabling automatic water replenishment to the reactor pool and effectively solving the problem of easy failure in the prior art. Attached Figure Description

[0018] To more clearly illustrate the technical solution of the present invention, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the structure provided in the first embodiment of the present invention;

[0020] Figure 2 This is a structural schematic diagram provided in the second embodiment of the present invention;

[0021] Figure 3 This is a structural schematic diagram provided in the third embodiment of the present invention.

[0022] The attached figures are labeled as follows:

[0023] 10. Reactor pool;

[0024] 20. Reactor vessel; 21. Heat exchange piping; 22. Emergency valves; 23. Heat exchange valves;

[0025] 30. Active cooling mechanism; 31. First circulating heat exchange circuit; 311. First inlet pipe section; 312. First return pipe section; 313. First circulating pump; 32. Second circulating heat exchange circuit; 321. Second circulating pump; 33. Third circulating heat exchange circuit; 331. Third circulating pump; 34. First heat exchanger; 35. Second heat exchanger; 36. Heat-using terminal;

[0026] 40. Passive cooling mechanism; 41. Screw expander; 42. Circulating water pump; 43. Cooling water tank; 44. Exhaust steam discharge pipeline;

[0027] 51. Pressure sensor; 52. Water level sensor; 53. Main control valve; 54. Backup passage valve;

[0028] 60. Factory buildings;

[0029] 70. Backup cooling system; 71. Backup screw expander; 72. Backup circulating water pump; 73. Backup exhaust steam discharge pipeline; 74. Backup water tank. Detailed Implementation

[0030] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings.

[0031] In existing technologies, the following methods are often used to cool down a reactor under special conditions.

[0032] The first method involves setting up pipelines to actively transport coolant for heat exchange; however, if this method loses its circulating cooling capacity due to a power outage, the water temperature in the pipelines will be almost the same as the water temperature in the reactor pool. Therefore, the reactor pool will not be cooled, and eventually the reactor pool will boil. The reactor will not be effectively cooled and will melt down due to overheating.

[0033] The second approach involves establishing a system where heat is transferred from the water pool to a heat exchanger, and then the heated water is transported to an air cooler outside the containment via a loop and natural circulation. The cooled water is then returned to the heat exchanger inside the water pool after being cooled by the external atmosphere. However, this requires a sufficiently large temperature difference between the external atmosphere and the water pool inside the containment, as well as sufficiently low loop resistance. If the external atmosphere temperature is too high, the water pool will not be able to be cooled, and eventually the water pool containing the reactor will boil, causing the reactor to overheat and melt down due to ineffective cooling.

[0034] The third option is to use the main steam pipeline of the steam generator and the automatic depressurization system to supply steam to the steam turbine, which drives the steam turbine to drive the feedwater pump to achieve automatic water circulation cooling; however, the steam turbine is a large secondary loop power generation device inherent in large pressurized water reactor nuclear power plants, which cannot be converted to use in pool reactors or shell reactors.

[0035] Since existing technologies have not yet found a suitable cooling method for pool-type or shell-type reactors, this invention provides a self-driven water supply system for the reactor body's water pool to address this problem. The core of this self-driven water supply system is that the steam generated in the reactor water pool 10 drives the screw expander 41 to operate. The screw expander 41 then generates driving force to control the circulating water pump 42 to continuously pump water to the reactor water pool 10, thereby achieving fully automatic water supply and cooling operation.

[0036] This self-driven water replenishment system has at least the following advantages:

[0037] First, the self-driven water replenishment system is powered by the steam generated in the reactor pool 10. No additional active drive equipment is needed. As long as the reactor is in a superheated state, steam will be generated continuously. If steam stops being generated, it means that the reactor has cooled down and there is no need to cool it down further.

[0038] Secondly, the self-driven water supply system ensures a continuous water input, guaranteeing that the water level in the reactor pool 10 will not drop below the warning line. Moreover, the continuous water input also ensures that steam can be continuously generated, thus providing a reliable power source for the self-driven water supply system.

[0039] Third, the screw expander 41 is much smaller in volume than the water turbine, which makes it possible to use steam to drive the cooling method of makeup water in pool reactors or shell reactors. This is an extremely important step in improving the safety of pool reactors or shell reactors. Moreover, the screw expander 41 is not only much more stable in operation than the water turbine, but also much easier to maintain. Therefore, it is more in line with the design requirements of a safe and reliable self-driven makeup water system.

[0040] To better illustrate the technical solution of the present invention in detail, several specific embodiments of the self-driven water replenishment system will be provided below.

[0041] Example 1

[0042] like Figure 1 As shown, this embodiment is a self-driven water replenishment system for the reactor body's water pool, including a reactor water pool 10, a reactor vessel 20, an active cooling mechanism 30, a passive cooling mechanism 40, and a monitoring mechanism.

[0043] Regarding the aforementioned reactor pool 10, the reactor pool 10 should be located within the reactor building 60, and the interior of the reactor pool 10 should be enclosed to form a sealed space to facilitate sealed water storage within the reactor pool 10. The sealed space formed by the reactor pool 10 is relatively sealed, not absolutely sealed, because other devices need to be connected inside the reactor pool 10, steam needs to be discharged, and water needs to be injected. Therefore, the sealed space referred to in the reactor pool 10 is a space where all connecting and conductive parts are sealed.

[0044] Regarding the aforementioned reactor vessel 20, the reactor vessel 20 should be located inside the reactor pool 10, and a heat exchange pipeline 21 should be provided on the outside of the reactor vessel 20 for heat exchange. The reactor vessel 20 is used to house the reactor. When the reactor is reacting, it will generate a large amount of heat. Under normal circumstances, this heat is absorbed and carried away by the active cooling mechanism 30. However, if a shutdown for maintenance or an accident occurs, the active cooling mechanism 30 will stop working, and the heat exchange pipeline 21 can be used for heat exchange instead.

[0045] Specifically, in order to achieve the application switching between the active cooling mechanism 30 and the heat exchange pipeline 21, this embodiment is provided with an emergency valve 22 connected to the pipeline for heat exchange between the active cooling mechanism 30 and the reactor vessel 20. Closing the emergency valve 22 is used to cut off the heat exchange between the active cooling mechanism 30 and the reactor vessel 20. The heat exchange pipeline 21 is connected to the active cooling mechanism 30, and a heat exchange valve 23 is connected to the heat exchange pipeline 21. The heat exchange valve 23 is used to control the opening and closing between the active cooling mechanism 30 and the heat exchange pipeline 21.

[0046] For example, when the reactor is operating normally, the emergency valve 22 is in the open state, the heat exchange valve 23 is in the closed state, and the active cooling mechanism 30 controls the coolant to circulate. Since the coolant flows through the reactor vessel 20 to absorb heat, the circulation of the coolant can remove the heat generated by the reactor in a timely manner.

[0047] In case of maintenance or accident, the heat exchange valve 23 can be opened to allow coolant to flow and fill the heat exchange pipe 21, then the operation of the active cooling mechanism 30 can be stopped, and the emergency valve 22 can be closed. Since the heat exchange pipe 21 is directly exposed in the internal space of the reactor pool 10, it will be in direct contact with the water in the reactor pool 10, or even be completely immersed in the water in the reactor pool 10. Because the heat exchange pipe 21 and the reactor vessel 20 are connected by a heat exchange connection in this embodiment, the heat generated in the reactor will first be transferred to the coolant in the heat exchange pipe 21, and then to the water in the reactor pool 10, so that the reactor can still be cooled in time after the active cooling mechanism 30 is shut down.

[0048] It should be noted that, in order to achieve the heat exchange connection between the heat exchange pipeline 21 and the reactor vessel 20, the two can be set to direct contact heat transfer, or the heat exchange connection can be achieved by using a heat exchanger; however, considering the reliability of operation in emergency situations, this embodiment preferably sets the heat exchange pipeline 21 and the reactor vessel 20 to direct contact for heat exchange, and no device is set to drive the coolant circulation, that is, the most basic contact heat transfer method is adopted to ensure long-term stable heat exchange in emergency situations.

[0049] Regarding the aforementioned active cooling mechanism 30, its main function is to ensure timely heat dissipation during normal reactor operation. Therefore, in this embodiment, the active cooling mechanism 30 is connected to the reactor vessel 20 for heat exchange. Specifically, the active cooling mechanism 30 in this embodiment includes a first circulating heat exchange loop 31, a second circulating heat exchange loop 32, a third circulating heat exchange loop 33, a first heat exchanger 34, a second heat exchanger 35, and a heat-using terminal 36. The first circulating heat exchange loop 31 is connected between the first heat exchanger 34 and the reactor vessel 20. An emergency valve 22 is connected to the first circulating heat exchange loop 31, and the first circulating heat exchange loop 31 is also connected to the heat exchange pipeline 21. The second circulating heat exchange loop 32 is connected between the first heat exchanger 34 and the second heat exchanger 35. The third circulating heat exchange loop 33 is connected between the second heat exchanger 35 and the heat-using terminal 36.

[0050] The first circulating heat exchange loop 31, the second circulating heat exchange loop 32, and the third circulating heat exchange loop 33 mentioned above can all be understood as a closed-loop pipeline, and corresponding circulating pumps are installed on the pipeline to realize the active circulation flow of the relevant fluids.

[0051] For example, the first circulating heat exchange loop 31 in this embodiment includes a first liquid delivery pipe section 311, a first liquid return pipe section 312, and a first circulating pump 313. The first liquid delivery pipe section 311 and the first liquid return pipe section 312 are connected to form a closed loop. The first liquid delivery pipe section 311 is used to deliver the cooled coolant to the reactor vessel 20 for heat absorption, and the first liquid return pipe section 312 is used to deliver the heated coolant to the first heat exchanger 34 for heat exchange and cooling. The first circulating pump 313 is connected to the first circulating heat exchange loop 31 to control the circulation of coolant in the first liquid delivery pipe section 311 and the first liquid return pipe section 312. Similarly, the second circulating heat exchange loop 32 is equipped with a second circulating pump 321 to realize liquid circulation flow control, and the third circulating heat exchange loop 33 is equipped with a third circulating pump 331 to realize liquid circulation flow control.

[0052] Emergency valves 22 are connected to both the first liquid delivery pipe section 311 and the first liquid return pipe section 312. When both emergency valves 22 are opened, the coolant can circulate within the first liquid delivery pipe section 311 and the first liquid return pipe section 312. When both emergency valves 22 are closed, the heat exchange between the active cooling mechanism 30 and the reactor vessel 20 is completely cut off. At this time, the reactor vessel 20 only has a heat exchange relationship with the opened heat exchange pipe 21.

[0053] Specifically, regarding the working process of the active cooling mechanism 30, when the active cooling mechanism 30 is working normally, the emergency valve 22 is in the open state, the heat exchange valve 23 is in the closed state, the first circulating heat exchange circuit 31 is filled with coolant, the first circulating pump 313 controls the coolant to flow to the reactor vessel 20 to absorb heat, and then the coolant flows back to the first heat exchanger 34. The first heat exchanger 34 will absorb the heat of the returning coolant so that the coolant is cooled down and then returns to the reactor vessel 20 to absorb heat. This cycle is repeated to achieve timely cooling of the reactor.

[0054] The heat absorbed by the first heat exchanger 34 will be sent to the second heat exchanger 35 through the second circulating heat exchange loop 32. Then, the second heat exchanger 35 will absorb the corresponding heat and send the absorbed heat to the heat-using terminal 36 through the third circulating heat exchange loop 33, so that the heat energy generated by the reactor can be rationally utilized.

[0055] For example, the heat terminal 36 may be a residential heating system, in which case the heat terminal 36 can use the heat generated by the reactor to provide heating for residents; or the heat terminal 36 may be a greenhouse plantation, in which case the heat terminal 36 can use the heat generated by the reactor to create a greenhouse environment.

[0056] Regarding the aforementioned passive cooling mechanism 40, its main function is to achieve cooling and heat dissipation during reactor emergency conditions. Specifically, in this embodiment, the passive cooling mechanism 40 includes a screw expander 41, a circulating water pump 42, and a cooling water pool 43. The power input end of the screw expander 41 is connected to the interior of the reactor water pool 10, and the power output end of the screw expander 41 is connected to the power input end of the circulating water pump 42. The vent of the screw expander 41 is connected to a waste steam discharge pipeline 44. The pumping end of the circulating water pump 42 is connected to the interior of the cooling water pool 43, and the supply end of the circulating water pump 42 is connected to the interior of the reactor water pool 10.

[0057] When the reactor enters a maintenance or accident state, the heat generated by the reactor will cause the water temperature in the reactor pool 10 to rise rapidly. At this time, a large amount of water vapor will be transported through pipelines to the power input end of the screw expander 41, thereby driving the screw expander 41 to generate driving force for the circulating water pump 42. The circulating water pump 42 can then pump water from the cooling water pool 43 through pipelines to the reactor pool 10 to ensure that the reactor is adequately cooled and to prevent the water level from becoming too low.

[0058] Among them, the screw expander 41 is a heat engine that relies on the expansion of gas volume to drive the screw rotor to rotate, converting thermal energy into mechanical energy. Compared with heat engines such as steam turbines and internal combustion engines, the screw expander 41 has a shorter development history and is a new type of power machinery that has achieved significant development in the 21st century. It can be widely used in fields such as industrial waste heat recovery, geothermal power generation, and biomass power generation. It can directly drive generators or directly drive mechanical equipment such as pumps and fans.

[0059] The screw expander 41 has a structure basically the same as that of a twin-screw compressor and works according to the reverse principle of gas compression. It mainly consists of a pair of meshing screw rotors and a casing. The rotors are sealed with gaps between them and between them and the casing, forming a working chamber with a continuously variable volume. The gaseous working fluid containing heat enters the working chamber and expands adiabatically, driving the rotor to rotate and do work. While expanding and doing work, the pressure and temperature of the working fluid decrease, thereby realizing the conversion of heat and work.

[0060] The main advantages of the screw expander 41 are as follows:

[0061] One advantage is the ability to achieve high isentropic efficiency. Excellent screw profile design and micron-level high-precision machining capabilities enable isentropic efficiency exceeding 85%, which is higher than that of velocity turbines.

[0062] Secondly, in addition to the superheated zone, it can reliably adapt to the gas-liquid two-phase zone (saturated steam), and can be used with both high- and low-grade heat sources.

[0063] Thirdly, the gap sealing principle provides a certain degree of descaling and self-cleaning ability.

[0064] Fourthly, the screw rotor has a moderate length-to-diameter ratio, good dynamic balance, is simple and reliable, has no easily damaged parts, and can operate for ten years without major repairs.

[0065] Fifthly, it can be fully automated and unattended.

[0066] It should also be noted that after the steam has finished working on the screw expander 41, the steam will flow through the exhaust steam discharge pipeline 44 and be discharged. Therefore, in order to avoid pollution to the outside world, in this embodiment, the exhaust steam discharge pipeline 44 is located in the building 60 where the reactor vessel 20 is placed. So the discharged steam will never be directly discharged to the outside world, thus providing an important role in improving safety.

[0067] The main function of the aforementioned monitoring mechanism is to monitor the interior of the reactor pool 10 in order to perform relevant control operations in a timely manner. Therefore, the monitoring mechanism in this embodiment includes a pressure sensor 51, a water level sensor 52, and a main control valve 53. Both the pressure sensor 51 and the water level sensor 52 are located inside the reactor pool 10. The main control valve 53 is connected to the power input terminal of the screw expander 41. When the pressure or water level in the reactor pool 10 exceeds the preset value, the monitoring mechanism is used to control the main control valve 53 to open.

[0068] For example, when the reactor vessel 20 is operating normally, the pressure inside the reactor pool 10 is low and the water level is high. Therefore, the monitoring agency will determine that the system is in a normal state and keep the main control valve 53 closed to ensure the sealing of the reactor pool 10.

[0069] However, if the reactor vessel 20 malfunctions, it will transfer heat to the reactor pool 10 through the heat exchange pipe 21. As a result, the reactor pool 10 will heat up and generate a large amount of water vapor, which will cause the internal pressure to rise and the water level to drop. Therefore, the monitoring agency will open the main control valve 53 at this time, which will use steam to drive the screw expander 41 to work and achieve the purpose of replenishing water to the reactor pool 10.

[0070] Example 2

[0071] A second embodiment of the self-driven water replenishment system of the present invention is as follows: Figure 2 As shown, it is basically the same as the first embodiment, except that the self-driven water replenishment system also includes a backup cooling mechanism 70, which includes a backup screw expander 71 and a backup circulating water pump 72; the power input end of the backup screw expander 71 is connected to the interior of the reactor pool 10, the power output end of the backup screw expander 71 is connected to the power input end of the backup circulating water pump 72, and the vent of the backup screw expander 71 is connected to a backup exhaust steam discharge pipeline 73; the pumping end of the backup circulating water pump 72 is connected to the interior of the cooling water pool 43, and the supply end of the backup circulating water pump 72 is connected to the interior of the reactor pool 10; the monitoring mechanism is also used to control the opening and closing of the backup screw expander 71 and the reactor pool 10.

[0072] The operation and effect of the standby screw expander 71 and the standby circulating water pump 72 are the same as those of the screw expander 41 and the circulating water pump 42 mentioned above, so they will not be described again. With this configuration, if the screw expander 41 and the circulating water pump 42 fail, the standby screw expander 71 and the standby circulating water pump 72 can be started to ensure the stable replenishment of water to the reactor pool 10. Of course, the standby screw expander 71 and the standby circulating water pump 72 are not limited to one set, and more can be set according to actual needs.

[0073] In addition, the monitoring mechanism in this embodiment also includes a backup passage valve 54 and a water flow sensor 55; the backup passage valve 54 is connected to the power input terminal of the backup screw expander 71; the water flow sensor 55 is located at the outlet of the circulating water pump 42 in the reactor pool 10; when the water supply of the circulating water pump 42 is measured to be lower than the preset value, the monitoring mechanism is used to control the backup passage valve 54 to open.

[0074] With this setup, the water flow sensor 55 can be used to determine if there is a problem with insufficient water supply to the circulating water pump 42. This ensures that if such a problem occurs, the backup passage valve 54 can be opened in time to continue to replenish water to the reactor pool 10 using the backup screw expander 71 and the backup circulating water pump 72, thus providing better protection for the system's safety.

[0075] Example 3

[0076] A third embodiment of the self-driven water replenishment system of the present invention is as follows: Figure 3 As shown, it is basically the same as the second embodiment, except that the backup cooling mechanism 70 also includes a backup water tank 74, and the pumping end of the backup circulating water pump 72 is connected to the interior of the backup water tank 74.

[0077] With the above configuration, even if the cooling water tank 43 experiences insufficient water supply due to special circumstances, water can be pumped from the backup water tank 74 using the backup cooling mechanism 70, thus providing more adequate preparation for dealing with special circumstances and further improving the safety of the system.

[0078] In addition, this embodiment also includes a monitoring mechanism that controls the main control valve 53 to close when the measured water supply of the circulating water pump 42 is lower than a preset value.

[0079] With this setup, once the main control valve 53 is closed, all the water vapor in the reactor pool 10 will be supplied to the standby cooling mechanism 70, thereby ensuring that the standby cooling mechanism 70 can obtain more power to work when the passive cooling mechanism 40 fails.

[0080] Furthermore, this embodiment also includes a monitoring mechanism that controls the main control valve 53 and the backup passage valve 54 to open when the water supply of the circulating water pump 42 is measured to be normal and the water level in the reactor pool 10 is lower than a preset value.

[0081] With this setup, even if the water supply rate of the passive cooling mechanism 40 cannot keep up with the steam generation rate in the reactor pool 10, the backup cooling mechanism 70 can be activated simultaneously, thus providing synchronized water supply through the two cooling mechanisms and making ample preparations for dealing with more extreme situations.

[0082] It should also be noted that the present invention provides a self-driven water replenishment method for the reactor body pool, which uses the above-mentioned self-driven water replenishment system. The active cooling mechanism 30 actively cools and dissipates heat from the reactor vessel 20. When the reactor is shut down or an accident occurs, the active cooling mechanism 30 is shut down and the heat exchange pipeline 21 is opened to exchange heat with the water in the reactor pool 10. If the pressure or water level in the reactor pool 10 exceeds the preset value, the monitoring mechanism controls the main control valve 53 to open. The steam generated in the reactor pool 10 drives the screw expander 41 to operate. The operation of the screw expander 41 drives the circulating water pump 42 to work. The circulating water pump 42 pumps water from the cooling water pool 43 to the reactor pool 10.

[0083] Using this self-driven water replenishment method will yield the same beneficial effects as described above, so it will not be described further here.

[0084] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A self-driven water replenishment system for the reservoir containing the reactor body, characterized in that, This includes the reactor pool, reactor vessel, active cooling system, passive cooling system, and monitoring system; The reactor pool is enclosed into a sealed space. The reactor vessel is located inside the reactor pool, and the reactor vessel is externally connected to a heat exchange pipeline. The active cooling mechanism is connected to the reactor vessel for heat exchange. The passive cooling mechanism includes a screw expander, a circulating water pump, and a cooling water tank; the power input end of the screw expander is connected to the interior of the reactor water tank, the power output end of the screw expander is connected to the power input end of the circulating water pump, and the exhaust port of the screw expander is connected to a waste steam discharge pipeline; the pumping end of the circulating water pump is connected to the interior of the cooling water tank, and the supply end of the circulating water pump is connected to the interior of the reactor water tank. The monitoring mechanism includes a pressure sensor, a water level sensor, and a main control valve; both the pressure sensor and the water level sensor are located inside the reactor pool; the main control valve is connected to the power input terminal of the screw expander; when the pressure in the reactor pool exceeds a preset value, or when the water level in the reactor pool is lower than a preset value, the monitoring mechanism controls the main control valve to open. The self-driven water replenishment system also includes a backup cooling mechanism, which includes a backup screw expander and a backup circulating water pump; The power input end of the standby screw expander is connected to the interior of the reactor pool, the power output end of the standby screw expander is connected to the power input end of the standby circulating water pump, and the vent of the standby screw expander is connected to a standby exhaust steam discharge pipeline. The pumping end of the standby circulating water pump is connected to the interior of the cooling water pool, and the supply end of the standby circulating water pump is connected to the interior of the reactor pool. The monitoring mechanism is also used to control the opening and closing of the standby screw expander and the reactor pool; The monitoring system also includes backup access valves and water flow sensors; The backup passage valve is connected to the power input terminal of the backup screw expander; The water flow sensor is located at the outlet of the circulating water pump in the reactor pool; When the water supply of the circulating water pump is measured to be lower than a preset value, the monitoring mechanism is used to control the opening of the backup passage valve; An emergency valve is connected to the pipeline through which the active cooling mechanism exchanges heat with the reactor vessel. Closing the emergency valve is used to cut off the heat exchange between the active cooling mechanism and the reactor vessel. The heat exchange pipeline is connected to the active cooling mechanism, and a heat exchange valve is connected to the heat exchange pipeline. The heat exchange valve is used to control the opening and closing of the active cooling mechanism and the heat exchange pipeline.

2. The self-driven water replenishment system according to claim 1, characterized in that, The backup cooling mechanism also includes a backup water tank, and the pumping end of the backup circulating water pump is connected to the interior of the backup water tank.

3. The self-driven water replenishment system according to claim 1, characterized in that, When the water supply of the circulating water pump is measured to be lower than the preset value, the monitoring mechanism is also used to control the main control valve to close.

4. The self-driven water replenishment system according to claim 1, characterized in that, When the water supply of the circulating water pump is measured to be normal and the water level in the reactor pool is lower than the preset value, the monitoring mechanism is used to control the opening of the main control valve and the backup passage valve.

5. The self-driven water replenishment system according to claim 1, characterized in that, The active cooling mechanism includes a first circulating heat exchange loop, a second circulating heat exchange loop, a third circulating heat exchange loop, a first heat exchanger, a second heat exchanger, and a heat-using terminal. The first circulating heat exchange loop is connected between the first heat exchanger and the reactor vessel. The first circulating heat exchange loop is connected to the emergency valve. The first circulating heat exchange loop is also connected to the heat exchange pipeline. The second circulating heat exchange loop is connected between the first heat exchanger and the second heat exchanger; The third circulating heat exchange loop is connected between the second heat exchanger and the heat-using terminal.

6. The self-driven water replenishment system according to claim 1, characterized in that, The exhaust steam discharge pipeline is located inside the building where the reactor vessel is situated.

7. A self-driven water replenishment method for the water pool containing the reactor body, employing the self-driven water replenishment system described in any one of claims 1 to 6, characterized in that, The active cooling mechanism actively cools and dissipates heat from the reactor vessel. When the reactor is shut down or an accident occurs, the active cooling mechanism is shut down and the heat exchange pipeline is opened to exchange heat with the water in the reactor pool. If the pressure in the reactor pool exceeds a preset value, or the water level in the reactor pool is found to be lower than a preset value, the monitoring mechanism controls the main control valve to open. The steam generated in the reactor pool drives the screw expander to operate, and the operation of the screw expander drives the circulating water pump to work. The circulating water pump draws water from the cooling water pool to the reactor pool.

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