Pressure relief system and pressure relief method after sodium water accident

Abstract

The invention provides a pressure relief system after a sodium water accident, which mainly comprises three relief pipelines where three relief valves are positioned, a multi-stage discharge assembly and a cold sodium pool, and is characterized in that an outlet of an intermediate heat exchanger where a first relief valve is positioned is connected with the relief pipeline of the cold sodium pool; the superheater lower cavity where the second release valve is located is connected with a release pipeline of the multi-stage discharge assembly, and the evaporator lower cavity where the third release valve is located is connected with the release pipeline of the multi-stage discharge assembly. The pressure detector and the temperature detector are installed in the intermediate heat exchanger, the superheater and the evaporator respectively, and the release valve acts after obtaining a detection signal. The multi-stage discharge assembly comprises multi-stage discharge tanks which are connected in series, and pressure relief pieces are installed on outlet pipelines of the multi-stage discharge tanks. And an intermediate heat exchanger is arranged in the cold sodium pool. The pressure relief system can reduce the probability of secondary accidents caused by overhigh pressure of a secondary loop under the condition that the passive rupture disk is exploded or the explosion fails, and effectively prevents equipment damage and even more serious safety accidents caused by pressure surge.

Description

Technical Field

[0001] The invention belongs to the technical field of local accident protection of sodium-cooled fast reactors, and in particular to a pressure relief system and a pressure relief method after a sodium-water accident. Background Art

[0002] In a sodium-cooled fast reactor, the rupture of the heat transfer tube of the steam generator will cause water or water vapor to flow into the liquid sodium, causing a sodium-water reaction. The sodium-water reaction is a highly exothermic chemical reaction that produces a large amount of hydrogen. The sodium-water reaction process will quickly release a large amount of heat energy, which cannot be immediately absorbed or dissipated by the system, so it will quickly accumulate in a local area. When the pressure exceeds the limit that the system can withstand, it will cause the system to explode, resulting in a serious sodium-water accident in the first circuit. In the process of pressure accumulation in the local area, the heat energy in the area is also gradually accumulated, and the temperature of the area will rise sharply. At the same time, the sudden increase in pressure will be transmitted to various key systems in the second circuit in the form of a pressure wave, causing the pressure in the second circuit to rise. In the second circuit, the pressure peak is now in the lower chamber of the intermediate heat exchanger, causing the intermediate heat exchanger to fail.

[0003] At present, in order to ensure the rapid pressure relief of the intermediate heat exchanger and protect the safety of the primary circuit after shutdown, passive bursting discs are often installed on the intermediate heat exchanger and other equipment. When the pressure exceeds the set value, the passive bursting disc will automatically burst and quickly release the pressure to protect the safety of the intermediate heat exchanger and the secondary circuit. After the passive bursting disc explodes, the passive bursting disc will fail, thereby increasing the probability of a secondary accident caused by untimely pressure relief of the secondary circuit. Summary of the invention

[0004] In order to solve the problem that after using passive rupture discs for pressure relief in existing sodium-cooled fast reactor systems, the passive rupture discs fail, resulting in secondary accidents due to untimely pressure relief of the secondary circuit, the present invention provides a pressure relief system and a pressure relief method after a sodium-water accident.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] The present invention provides a pressure relief system after a sodium water accident, comprising a cold sodium pool, wherein an intermediate heat exchanger is installed in the cold sodium pool, wherein a liquid sodium outlet of the intermediate heat exchanger is connected to a liquid sodium inlet of a superheater through a connecting pipe, wherein the liquid sodium outlet of the superheater is connected to a liquid sodium inlet of an evaporator through a connecting pipe, and wherein the liquid sodium outlet of the evaporator is connected to a liquid sodium processing device through a connecting pipe;

[0007] The superheater and the evaporator are connected to a passage control component through a pipeline, the passage control component is connected to a multi-stage discharge component, the passage control component and the multi-stage discharge component are signal-connected to a detector, and the detector is installed in the intermediate heat exchanger, the superheater and the evaporator respectively;

[0008] The multi-stage discharge assembly comprises multi-stage discharge tanks connected in series, one end interface of the multi-stage discharge tanks is respectively connected to the passage control assembly through pipelines, and the other end interface of the multi-stage discharge tanks is installed with a pressure relief component.

[0009] Preferably, the multi-stage discharge tank includes a first-stage discharge tank, the inlet of the first-stage discharge tank is connected to the passage control component through a pipeline, the outlet of the first-stage discharge tank is connected to the inlet of the second-stage discharge tank through a pipeline, and the pressure relief component is installed on the outlet of the second-stage discharge tank.

[0010] Preferably, the pressure relief component is a discharge tank bursting disc.

[0011] Preferably, the passage control assembly comprises a second discharge pipe valve and a third discharge pipe valve, one end of the second discharge pipe valve is connected to the discharge pipe of the superheater through a pipeline, and the other end of the second discharge pipe valve is connected to the inlet of the primary discharge tank through a pipeline;

[0012] One end port of the third discharge pipe valve is connected to the discharge pipe of the evaporator through a pipeline, and the other end port of the third discharge pipe valve is connected to the inlet of the primary discharge tank through a pipeline.

[0013] Preferably, a superheater bursting disc is connected between the inlet of the primary discharge tank and the discharge pipe of the superheater via a pipeline.

[0014] Preferably, an evaporator bursting disc is connected between the inlet of the primary discharge tank and the discharge pipe of the evaporator through a pipeline.

[0015] Preferably, a pressure gauge and a liquid level gauge are installed in both the primary discharge tank and the secondary discharge tank.

[0016] Preferably, a first discharge pipe valve is connected to the connecting pipe between the liquid sodium outlet of the intermediate heat exchanger and the liquid sodium inlet of the superheater through a pipeline, the first discharge pipe valve is connected to the cold sodium pool, and the first discharge pipe valve signal is connected to the detector.

[0017] Preferably, the detector is connected with a warning component, which includes a warning light, a warning processor and a voice alarm, the warning light and the voice alarm signal are connected to the warning processor, and the warning processor signal is connected to the detector.

[0018] The present invention provides a pressure relief method after a sodium water accident, which is applied to the above-mentioned pressure relief system and comprises the following steps:

[0019] Step 1, the detector obtains real-time pressure data and real-time temperature data in the intermediate heat exchanger, superheater and evaporator, and compares them with corresponding preset pressure data and preset temperature data, and generates a control signal based on the comparison result;

[0020] Step 2, the first discharge pipe valve conducts the passage between the connecting pipeline between the intermediate heat exchanger and the superheater and the cold sodium pool based on the control signal, thereby depressurizing the intermediate heat exchanger and discharging liquid sodium;

[0021] The second discharge pipe valve conducts the pipeline between the superheater and the first-stage discharge tank based on the control signal to relieve the pressure of the superheater and discharge liquid sodium;

[0022] The third discharge pipe valve conducts the pipeline between the evaporator and the primary discharge tank based on the control signal to relieve the pressure of the evaporator and discharge liquid sodium;

[0023] Step 3, the pressure gauge and the liquid level gauge detect the pressure value and the liquid sodium level in the primary discharge tank, so that the primary discharge tank releases pressure into the secondary discharge tank and discharges liquid sodium; the evaporator bursting disc on the secondary discharge tank opens to release a mixture of hydrogen and argon into the air, thereby depressurizing the system after the sodium-water reaction accident of the sodium-cooled fast reactor.

[0024] Compared with the prior art, the present invention has the following beneficial technical effects:

[0025] The present invention provides a pressure relief system after a sodium-water accident. The system realizes effective cooling and circulation treatment of high-temperature liquid sodium through the serial arrangement of a cold sodium pool, an intermediate heat exchanger, a superheater, an evaporator and a liquid sodium processing device, effectively responds to the extreme high temperature and pressure surge that may be caused by the sodium-water reaction. In the system, the detector monitors the temperature, pressure and other key parameters in the intermediate heat exchanger, the superheater and the evaporator in real time. If an abnormality is detected, such as temperature exceeding the standard or pressure rising sharply, the passage control component will respond quickly, automatically adjust the fluid flow direction, and guide the high-temperature and high-pressure liquid sodium to flow to the multi-stage discharge component, thereby improving the stability of the pressure relief after the sodium-water reaction accident of the sodium-cooled fast reactor. The multi-stage discharge component adopts a multi-stage discharge tank connected in series to reduce the pressure and temperature of the liquid sodium step by step, ensuring that no harm is caused to the external environment during the discharge process, and then quickly completes the pressure release, effectively preventing the damage to the equipment or more serious safety accidents that may be caused by the system overpressure. When the system detects an abnormality in the intermediate heat exchanger, the superheater or the evaporator, it can quickly start the multi-stage discharge mechanism and release the pressure step by step, effectively preventing the damage to the equipment or even more serious safety accidents caused by the pressure surge. At the same time, the ingenious layout of the cold sodium pool and heat exchange system ensures the continuous circulation and heat exchange of the sodium liquid, maintaining the stable operation of the system. The entire system responds quickly and controls precisely, providing a safer and more reliable guarantee for industrial fields such as nuclear energy.

[0026] Furthermore, the multi-stage emission tanks in the system adopt a first-stage emission tank and a second-stage emission tank in series arrangement. The first-stage emission tank serves as a preliminary pressure reduction link to effectively alleviate the impact force of high-temperature and high-pressure liquid sodium. Subsequently, the outlet of the first-stage emission tank is connected to the inlet of the second-stage emission tank through a pipeline to achieve further pressure reduction and gradual temperature cooling, which not only improves the stability and reliability of the system, but also realizes efficient and safe processing of high-temperature liquid sodium, thereby improving the safety and efficiency of the system.

[0027] Furthermore, the system uses discharge tank bursting discs as pressure relief parts for multi-stage discharge tanks to quickly respond to overpressure, enhance system safety, and effectively prevent accidents from expanding.

[0028] Furthermore, the second discharge pipe valve and the third discharge pipe valve in the system respectively accurately control the fluid path from the superheater and the evaporator to the first-level discharge tank, ensuring that the high-temperature and high-pressure liquid sodium can be quickly and orderly transferred to the safe processing link in an emergency. The superheater bursting disc and the evaporator bursting disc are added between the inlet of the first-level discharge tank and the discharge pipes of the superheater and the evaporator, which greatly enhances the safety protection capability of the system. The superheater bursting disc and the evaporator bursting disc are used as pre-pressure relief devices, which can respond in advance before the system pressure reaches the preset threshold, and release the pressure by instantaneous rupture, effectively preventing the equipment damage or more serious accidents caused by the continuous increase in pressure, which not only reduces the processing pressure of the subsequent discharge tank, but also improves the stability and safety of the overall system. The pressure relief system of the present invention realizes efficient and safe processing of high-temperature liquid sodium, and effectively responds to the challenges brought by the sodium water accident. The synergistic effect of the discharge tanks at all levels and the bursting discs ensures that the pressure and temperature are gradually reduced until the safe discharge standard is reached, which not only improves the automation and intelligence level of the system, but also provides a strong guarantee for the sustainable development of nuclear energy and related industrial fields.

[0029] Furthermore, in this system, pressure gauges and liquid level gauges are installed in both the primary and secondary discharge tanks. By real-time monitoring of the pressure and liquid level changes in the tanks, operators can accurately grasp the working status of the discharge tanks and take corresponding measures to deal with abnormal situations in a timely manner. This not only enhances the safety and stability of the system, but also ensures that high-temperature liquid sodium can be safely and efficiently processed, greatly improving the system's monitoring capabilities and operating efficiency.

[0030] Furthermore, in the present system, a first discharge pipe valve is added to the connecting pipeline between the liquid sodium outlet of the intermediate heat exchanger and the liquid sodium inlet of the superheater, and is directly connected to the cold sodium pool. At the same time, the valve signal is connected to the detector, which enhances the emergency response capability and flexibility of the system. When the detector detects abnormal pressure or temperature in the intermediate heat exchanger or subsequent pipelines, the first discharge pipe valve can respond quickly, automatically open and safely guide the high-temperature liquid sodium back to the cold sodium pool for cooling treatment, which not only effectively avoids further damage to the system by high-temperature and high-pressure liquid sodium, but also ensures the continuity and stability of the entire treatment process.

[0031] The present invention provides a pressure relief method after a sodium-water accident. The method realizes the rapid and effective treatment of high-temperature and high-pressure liquid sodium in a sodium-cooled fast reactor system by integrating intelligent detection, precise control and multi-stage discharge technology. The method first uses a detector to monitor the pressure and temperature in the intermediate heat exchanger, superheater and evaporator in real time. Once an abnormality is found, a control signal is immediately generated to quickly start the first, second and third discharge pipe valves to guide the high-temperature liquid sodium to the cold sodium pool and the multi-stage discharge tank for cooling and pressure reduction. Subsequently, through the precise monitoring of the pressure gauge and the liquid level gauge, it is ensured that the pressure and liquid level in the first-stage discharge tank are within the safe range, and it is transferred to the second-stage discharge tank in a timely manner, and finally the hydrogen and argon mixture is safely released through the evaporator bursting disc to achieve comprehensive pressure relief of the system. This method not only improves the emergency response speed, but also enhances the processing efficiency and safety, and provides a solid guarantee for the safe operation of the sodium-cooled fast reactor. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 A schematic diagram of the connection of a pressure relief system after a sodium water accident provided by the present invention;

[0033] In the attached figure: 1. cold sodium pool; 2. intermediate heat exchanger; 3. first discharge pipe valve; 4. superheater; 5. superheater bursting disc; 6. second discharge pipe valve; 7. evaporator; 8. evaporator bursting disc; 9. third discharge pipe valve; 10. primary discharge tank; 11. secondary discharge tank; 12. discharge tank bursting disc. DETAILED DESCRIPTION

[0034] In the following, only some exemplary embodiments are briefly described. As those skilled in the art will appreciate, the described embodiments may be modified in various ways without departing from the spirit or scope of the present invention. Therefore, the drawings and descriptions are considered to be exemplary and non-restrictive in nature.

[0035] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0036] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0037] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or a communication; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0038] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0039] The embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0040] See also Figure 1 The present invention proposes a pressure relief system after a sodium water accident. The system comprises a cold sodium pool 1, in which a plurality of intermediate heat exchangers 2 are installed. The liquid sodium outlet of each intermediate heat exchanger 2 is connected to the liquid sodium inlet of a superheater 4 through a connecting pipe, the liquid sodium outlet of the superheater 4 is connected to the liquid sodium inlet of an evaporator 7 through a connecting pipe, and the liquid sodium outlet of the evaporator 7 is connected to a liquid sodium processing component;

[0041] Among them, one end port of the first discharge pipe valve 3 is connected to the connecting pipeline between the liquid sodium outlet of the intermediate heat exchanger 2 and the liquid sodium inlet of the superheater 4 through a pipeline, and the other end port of the first discharge pipe valve 3 is connected to the cold sodium pool 1 through a pipeline. The signal of the first discharge pipe valve 3 is connected to the detector, and the detector is respectively installed in the intermediate heat exchanger 2, the superheater 4 and the evaporator 7. When the detector detects that the pressure of the intermediate heat exchanger 2 rises, and detects that the sodium-water reaction occurs in the superheater 4 or the evaporator 7, causing the pressure to rise sharply and the temperature to be abnormal, the detector sends a signal to the first discharge pipe valve 3, so that the first discharge pipe valve 3 is opened, and the liquid sodium transported from the intermediate heat exchanger 2 to the superheater 4 is quickly transported to the cold sodium pool 1, so as to prevent the superheater 4 from overpressure, overheating or even explosion, thereby protecting the safety of the superheater 4 and the operator. When the intermediate heat exchanger 2 or the superheater 4 fails, the first discharge pipe valve 3 serves as an isolation point to isolate the faulty part from the rest of the system to reduce the impact of the fault on the overall operation of the system.

[0042] The port of the discharge pipe on the superheater 4 is connected to one end of a second discharge pipe valve 6, and the other end of the second discharge pipe valve 6 is connected to a multi-stage discharge component through a pipeline. The signal of the second discharge pipe valve 6 is also connected to a detector. When the detector detects that the pressure in the superheater 4 or the evaporator 7 rises sharply or the temperature is abnormal, the signal controls the second discharge pipe valve 6 to open, and the liquid sodium in the superheater 4 is transported to the multi-stage discharge component, so as to avoid the rupture of the heat transfer tube of the superheater 4 or the evaporator 7, which leads to the sodium-water reaction, and the superheater 4 is prevented from being over-pressurized, overheated or even exploded, thereby improving the safety of the system.

[0043] The port of the discharge pipe on the superheater 4 is also connected to one end port of the superheater bursting disc 5 through a pipeline, and the other end port of the superheater bursting disc 5 is also connected to the multi-stage discharge assembly, and the superheater bursting disc 5 and the second discharge pipe valve 6 form two discharge passages in the discharge pipe of the superheater 4 and the multi-stage discharge assembly. When the heat transfer tube of the superheater 4 or the evaporator 7 ruptures, resulting in a sodium-water reaction, the pressure and temperature in the superheater 4 rise sharply, and the superheater 4 is depressurized, cooled, and sodium is discharged through the superheater bursting disc 5, so as to further protect the superheater 4 and improve the safety of the superheater 4 after the sodium-water reaction accident.

[0044] The port of the discharge pipe on the evaporator 7 is connected to one end port of the third discharge pipe valve 9 through a pipeline, and the other end port of the third discharge pipe valve 9 is also connected to the multi-stage discharge component through a pipeline. The signal of the third discharge pipe valve 9 is connected to the detector. When the detector detects that the pressure in the intermediate heat exchanger 2, the superheater 4 and the evaporator 7 increases sharply or the temperature is abnormal, the signal controls the third discharge pipe valve 9 to open, and the liquid sodium in the evaporator 7 is transported to the multi-stage discharge component to avoid the sodium-water reaction caused by the rupture of the heat transfer tube of the superheater 4 or the evaporator 7, and the pressure in the superheater 4 or the intermediate heat exchanger 2 increases. The formed pressure wave is transmitted to the evaporator 7, causing the evaporator 7 to be overpressured, overheated or even exploded, thereby improving the safety of the system.

[0045] The port of the discharge pipe on the evaporator 7 is also connected to one end port of the evaporator bursting disc 8 through a pipeline, and the other end port of the evaporator bursting disc 8 is also connected to the multi-stage discharge assembly, and the evaporator bursting disc 8 and the third discharge pipe valve 9 form two discharge passages in the discharge pipe and the multi-stage discharge assembly of the evaporator 7. When the heat transfer tube of the superheater 4 or the evaporator 7 ruptures, causing the sodium-water reaction to occur, and the pressure and temperature in the evaporator 7 rise sharply, the superheater 4 is depressurized, cooled, and sodium is discharged through the evaporator bursting disc 8, so as to further protect the evaporator 7 and improve the safety of the evaporator 7 after the sodium-water reaction accident.

[0046] The multi-stage discharge assembly includes a multi-stage discharge tank, which includes a first-stage discharge tank 10. The inlet of the first-stage discharge tank 10 is connected to the superheater bursting disc 5, the second discharge pipe valve 6, the evaporator bursting disc 8 and the third discharge pipe valve 9 through pipelines. The outlet of the first-stage discharge tank 10 is connected to the inlet of the second-stage discharge tank 11 through a pipeline, and the outlet of the second-stage discharge tank 11 is connected to the discharge tank bursting disc 12. The multi-stage discharge tank can release pressure step by step under different pressures or fault conditions to avoid damage to the discharge tank or casualties that may be caused by instantaneous pressure release. Each stage of the discharge tank serves as a buffer for the previous stage to ensure a smooth and orderly discharge process.

[0047] The discharge tanks of the multi-stage discharge assembly are equipped with pressure gauges and liquid level gauges, which are used to monitor the pressure and liquid sodium conditions in the discharge tanks. If the pressure value in the first-stage discharge tank 10 reaches a preset pressure value or the liquid sodium level exceeds the preset liquid sodium level, the first-stage discharge tank 10 transports liquid sodium to the second-stage discharge tank 11 or relieves pressure, and the second-stage discharge tank 11 releases a mixture of hydrogen and argon into the air through the discharge tank bursting disc 12 to avoid explosion of the multi-stage discharge assembly.

[0048] The detector is connected with a warning component, which includes a warning light, a warning processor and a voice alarm. The warning light and voice alarm signals are connected to the warning processor, and the warning processor signals are connected to the detector. The warning light and voice alarm are used to warn the staff.

[0049] The present invention proposes a pressure relief method after a sodium water accident, and the method comprises the following steps:

[0050] Step 1, the detector obtains real-time pressure data and real-time temperature data in the intermediate heat exchanger, superheater and evaporator, compares the obtained real-time pressure data with the preset pressure data, and compares the real-time temperature data with the preset temperature data. If the real-time pressure data exceeds the preset pressure data or the real-time temperature data exceeds the preset temperature data, it is determined that the system has a sodium-water response, and a control signal is generated;

[0051] Step 2: After receiving the control signal, the valve of the first discharge pipe is opened, the connecting pipeline between the liquid sodium outlet of the intermediate heat exchanger and the liquid sodium inlet of the superheater is connected to the cold sodium pool, and the liquid sodium transported from the intermediate heat exchanger to the superheater is discharged into the cold sodium pool;

[0052] The second discharge pipe valve is opened after receiving the control signal, connecting the pipeline between the discharge pipe on the superheater and the inlet of the first-stage discharge tank, and transporting the liquid sodium and pressure in the superheater to the first-stage discharge tank;

[0053] The third discharge pipe valve is opened after receiving the control signal, connecting the pipeline between the discharge pipe on the evaporator and the inlet of the first-stage discharge tank, and transporting the liquid sodium and pressure in the evaporator to the first-stage discharge tank;

[0054] Step 3, the pressure gauge detects the pressure value in the first-level discharge tank, and the liquid level gauge detects the liquid sodium level in the first-level discharge tank. If the pressure value reaches a preset pressure value or the liquid sodium level exceeds the preset liquid sodium level, the first-level discharge tank releases pressure and discharges liquid sodium into the second-level discharge tank; the evaporator bursting disc on the second-level discharge tank opens to release a mixture of hydrogen and argon into the air, thereby depressurizing the system after the sodium-water reaction accident of the sodium-cooled fast reactor.

[0055] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It is obvious to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic features of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is defined by the attached claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present invention. Any figure mark in the claims should not be regarded as limiting the claims involved.

[0056] In addition, it should be understood that although this specification is described in accordance with the implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation modes that can be understood by those skilled in the art. The above content is only to illustrate the technical idea of ​​the present invention, and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution according to the technical idea proposed by the present invention shall fall within the protection scope of the claims of the present invention.

Claims

1. A pressure relief system after a sodium water accident, characterized in that: It comprises a cold sodium pool (1), an intermediate heat exchanger (2) is installed in the cold sodium pool (1), a liquid sodium outlet of the intermediate heat exchanger (2) is connected to a liquid sodium inlet of a superheater (4) via a connecting pipe, the liquid sodium outlet of the superheater (4) is connected to a liquid sodium inlet of an evaporator (7) via a connecting pipe, and the liquid sodium outlet of the evaporator (7) is connected to a liquid sodium processing device via a connecting pipe; The superheater (4) and the evaporator (7) are connected to a passage control component via a pipeline, the passage control component is connected to a multi-stage discharge component, the passage control component and the multi-stage discharge component are signal-connected to a detector, and the detector is respectively installed in the intermediate heat exchanger (2), the superheater (4) and the evaporator (7); The multi-stage discharge assembly comprises multi-stage discharge tanks connected in series, one end interface of the multi-stage discharge tanks is respectively connected to the passage control assembly through pipelines, and the other end interface of the multi-stage discharge tanks is installed with a pressure relief component.

2. A pressure relief system after a sodium water accident according to claim 1, characterized in that: The multi-stage discharge tank comprises a primary discharge tank (10), the inlet of the primary discharge tank (10) is connected to the passage control component via a pipeline, the outlet of the primary discharge tank (10) is connected to the inlet of a secondary discharge tank (11) via a pipeline, and the pressure relief component is installed at the outlet of the secondary discharge tank (11).

3. A pressure relief system after a sodium water accident according to claim 2, characterized in that: The pressure relief component is a discharge tank bursting disc (12).

4. A pressure relief system after a sodium water accident according to claim 2, characterized in that: The passage control assembly comprises a second discharge pipe valve (6) and a third discharge pipe valve (9), one end of the second discharge pipe valve (6) is connected to the discharge pipe of the superheater (4) through a pipeline, and the other end of the second discharge pipe valve (6) is connected to the inlet of the primary discharge tank (10) through a pipeline; One end of the third discharge pipe valve (9) is connected to the discharge pipe of the evaporator (7) through a pipeline, and the other end of the third discharge pipe valve (9) is connected to the inlet of the primary discharge tank (10) through a pipeline.

5. A pressure relief system after a sodium water accident according to claim 2, characterized in that: A superheater bursting disc (5) is connected between the inlet of the primary discharge tank (10) and the discharge pipe of the superheater (4) via a pipeline.

6. A pressure relief system after a sodium water accident according to claim 2, characterized in that: An evaporator bursting disc (8) is connected between the inlet of the primary discharge tank (10) and the discharge pipe of the evaporator (7) via a pipeline.

7. A pressure relief system after a sodium water accident according to claim 2, characterized in that: A pressure gauge and a liquid level gauge are installed in both the primary discharge tank (10) and the secondary discharge tank (11).

8. The pressure relief system after a sodium water accident according to claim 1, characterized in that: A first discharge pipe valve (3) is connected to the connecting pipe between the liquid sodium outlet of the intermediate heat exchanger (2) and the liquid sodium inlet of the superheater (4) through a pipeline, the first discharge pipe valve (3) is connected to the cold sodium pool (1), and the first discharge pipe valve (3) is signal-connected to the detector.

9. A pressure relief system after a sodium water accident according to claim 1, characterized in that: The detector is connected with a warning component, which includes a warning light, a warning processor and a voice alarm. The warning light and the voice alarm are connected to the warning processor by signal, and the warning processor is connected to the detector by signal.

10. A pressure relief method after a sodium water accident, applied to the pressure relief system according to any one of claims 1 to 9, characterized in that: The following steps are involved: Step 1, the detector obtains real-time pressure data and real-time temperature data in the intermediate heat exchanger, superheater and evaporator, and compares them with corresponding preset pressure data and preset temperature data, and generates a control signal based on the comparison result; Step 2, the first discharge pipe valve conducts the passage between the connecting pipeline between the intermediate heat exchanger and the superheater and the cold sodium pool based on the control signal, thereby depressurizing the intermediate heat exchanger and discharging liquid sodium; The second discharge pipe valve conducts the pipeline between the superheater and the first-level discharge tank based on the control signal to relieve the pressure of the superheater and discharge liquid sodium; The third discharge pipe valve conducts the pipeline between the evaporator and the primary discharge tank based on the control signal to relieve the pressure of the evaporator and discharge liquid sodium; Step 3, the pressure gauge and the liquid level gauge detect the pressure value and the liquid sodium level in the primary discharge tank, so that the primary discharge tank releases pressure into the secondary discharge tank and discharges liquid sodium; the evaporator bursting disc on the secondary discharge tank opens to release a mixture of hydrogen and argon into the air, thereby depressurizing the system after the sodium-water reaction accident of the sodium-cooled fast reactor.

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