A nuclear power plant secondary side waste heat removal system driven by ORC based on jet technology

Abstract

The application discloses a nuclear power plant secondary side waste heat discharge system driven by an ORC based on a jet technology, and belongs to the technical field of nuclear power plant safety. The non-active natural circulation system comprises a non-active natural circulation loop formed by a steam generator and a vertical pipe cooler which are sequentially connected. The steam generator, the high-efficiency heat exchanger, the air-cooled heat exchanger and the vertical pipe cooler form a secondary side water circulation loop, and the high-efficiency heat exchanger, the ORC turbine, the ORC generator, the ORC condenser and the gas-liquid ejector form an organic Rankine cycle loop. The active system and the non-active system are mutually backed up, the timely discharge of the secondary side waste heat can be realized, the heat discharge effect is good, and the safety and reliability of the system are greatly guaranteed.

Description

Technical Field

[0001] This invention relates to the field of nuclear power plant safety technology, and specifically to a secondary side residual heat removal system for nuclear power plants based on jet technology-driven ORC. Background Technology

[0002] Nuclear power, with its high energy density and low pollution emissions, has become an important component of my country's modern energy system. Most commercially operating nuclear power units worldwide currently employ second-generation nuclear power technology. However, the severe accidents at Three Mile Island, Chernobyl, and Fukushima nuclear power plants between 1979 and 2011 have raised public concerns about the safety of nuclear power. Third-generation nuclear power technology, building upon the mature pressurized water reactor technology, incorporates lessons learned from second-generation operation, uses severe accidents as a design benchmark, considers the containment load under severe accident conditions, and employs passive severe accident mitigation measures. This significantly reduces the likelihood of human error, resulting in substantial improvements in both safety and economic efficiency.

[0003] Although existing nuclear power technology safety systems have added passive safety designs, the limited volume of the cooling water tanks in passive safety systems, coupled with the possibility of damage to facilities in the event of natural disasters such as earthquakes and tsunamis, means that safety hazards still exist, resulting in the inability to guarantee the safety and reliability of the system. In addition, the limited cooling capacity of passive systems in existing technologies makes it impossible to remove residual heat from the reactor core in a timely manner. Summary of the Invention

[0004] This invention addresses the technical problem of limited cooling capacity in existing passive systems, which cannot promptly remove residual heat from the reactor core, thus compromising system safety and reliability. The aim is to provide a secondary-side residual heat removal system for nuclear power plants based on an ORC driven by jet technology. This system combines an organic Rankine cycle (ORC) system with a passive natural circulation system, enabling mutual backup between the active and passive systems. It ensures timely removal of secondary-side residual heat under any circumstances, significantly enhancing system safety and reliability. The system features high safety and excellent heat removal efficiency.

[0005] This invention is achieved through the following technical solution:

[0006] A secondary-side residual heat removal system for nuclear power plants based on jet technology-driven ORC includes a passive natural circulation system and an organic Rankine cycle system;

[0007] The passive natural circulation system includes a steam generator and a vertical tube cooler connected in sequence. The vertical tube cooler condenses the steam from the steam generator to form condensate, and the condensate flows back into the steam generator by gravity, forming a passive natural circulation loop.

[0008] The organic Rankine cycle system includes a high-efficiency heat exchanger, an air-cooled heat exchanger, an ORC turbine, an ORC generator, an ORC condenser, and a gas-liquid ejector. The high-efficiency heat exchanger, the air-cooled heat exchanger, the vertical tube cooler, the ORC condenser, and the gas-liquid ejector are connected in sequence. The ORC condenser is connected to the high-efficiency heat exchanger through the ORC turbine. The ORC generator is driven by the ORC turbine and supplies power to the electrical equipment. The gas-liquid ejector is also connected to the high-efficiency heat exchanger.

[0009] The steam generator, high-efficiency heat exchanger, air-cooled heat exchanger and vertical tube cooler constitute the secondary side water circulation loop, while the high-efficiency heat exchanger, ORC turbine, ORC generator, ORC condenser and gas-liquid ejector constitute the organic Rankine cycle loop.

[0010] As a further technical solution of the present invention

[0011] (1) When a serious accident occurs at a nuclear power plant, resulting in reactor shutdown and power outage.

[0012] The high-efficiency heat exchanger is introduced into an organic working medium to cool the steam from the steam generator. The cooled steam is then sequentially introduced into an air-cooled heat exchanger and a vertical tube cooler to form condensate. The condensate flows back into the steam generator by gravity, forming a secondary side water circulation loop.

[0013] After heat exchange, the organic working fluid forms organic vapor. Part of the organic vapor enters the ORC turbine to expand and do work, driving the ORC generator to generate electricity for the power equipment. The vertical tube cooler introduces condensate into the ORC condenser and cools the organic vapor after it expands and does work, forming a subcooled liquid. Another part of the organic vapor enters the gas-liquid ejector and is drawn into the subcooled liquid before flowing back into the high-efficiency heat exchanger, forming an organic Rankine loop.

[0014] (2) When the organic Rankine cycle system fails, the passive natural cycle system is activated;

[0015] (3) When a serious accident occurs and the ORC loop is operating normally, as the decay heat decreases, the temperature and pressure of the outlet steam of the steam generator and the organic working fluid in the organic Rankine cycle system decrease, the organic Rankine cycle loop is closed, and the secondary side water cycle loop and the passive natural circulation system are in operation.

[0016] As a further technical solution of the present invention, an isolation valve is provided on the outlet pipe connected to the steam generator, and an isolation valve and a check valve are also provided on the return pipe connected to the steam generator.

[0017] As a further technical solution of the present invention, the inlet and outlet of the vertical tube cooler are connected to the heat sink to form a loop.

[0018] As a further technical solution of the present invention, the steam inlet of the vertical tube cooler is connected to the outlet of the steam generator and the outlet of the air-cooled heat exchanger, and the condensate outlet of the vertical tube cooler is connected to the ORC condenser and the water pump.

[0019] As a further technical solution of the present invention, the organic working fluid inlet of the high-efficiency heat exchanger is connected to the organic working fluid storage tank, the organic vapor outlet of the high-efficiency heat exchanger is connected to the ORC turbine and the gas-liquid ejector, and the vapor outlet of the high-efficiency heat exchanger is connected to the inlet of the air-cooled heat exchanger.

[0020] As a further technical solution of the present invention, a shut-off valve six and a check valve three are provided on the connecting pipe between the organic working fluid storage tank and the high-efficiency heat exchanger, and a regulating valve three is provided on the inlet pipe of the organic working fluid storage tank.

[0021] As a further technical solution of the present invention, the organic vapor inlet of the ORC turbine is connected to the organic vapor outlet of the high-efficiency heat exchanger, and the organic vapor outlet of the ORC turbine is connected to the ORC condenser.

[0022] As a further technical solution of the present invention, the organic vapor inlet of the gas-liquid ejector is connected to the organic vapor outlet of the high-efficiency heat exchanger, and the gas-liquid ejector is also connected to the subcooled liquid outlet of the ORC condenser.

[0023] As a further technical solution of the present invention, a regulating valve is provided on the connecting pipe between the gas-liquid ejector inlet and the high-efficiency heat exchanger, a check valve is provided on the connecting pipe between the gas-liquid ejector outlet and the high-efficiency heat exchanger, and a regulating valve is provided on the connecting pipe between the ORC turbine and the high-efficiency heat exchanger.

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

[0025] 1. In the event of a severe accident at a nuclear power plant, the system of the present invention utilizes a gas-liquid ejector to provide driving force for the ORC loop to generate electricity, which powers the electrical equipment in the secondary waste heat removal system. It is combined with a passive natural circulation system, and the two work simultaneously to ensure timely removal of secondary waste heat without relying on external power. It can quickly remove heat in the early stages of a severe accident, ensuring the safety and reliability of the system and solving the problem of limited cooling capacity of passive systems in the prior art.

[0026] 2. In the later stages of an accident or in the event of an ORC loop failure, the system of the present invention can be switched to a passive natural circulation mode, utilizing the secondary side water circulation loop and the passive natural circulation loop to remove residual heat from the secondary side, thereby ensuring the safety of the nuclear power plant.

[0027] 3. By combining an organic Rankine cycle system and a passive natural circulation system, the present invention enables the active and passive systems to back each other up, and can achieve timely discharge of secondary side waste heat under any circumstances, greatly ensuring the safety and reliability of the system. Attached Figure Description

[0028] To more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of the present invention and should not be considered as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort. In the drawings:

[0029] Figure 1 This is a schematic diagram of the structure of the present invention.

[0030] The attached diagram shows the markings and corresponding component names:

[0031] 1-Steam generator, 2-Isolation valve one, 3-Stop valve one, 4-Stop valve two, 5-High-efficiency heat exchanger, 6-Air-cooled heat exchanger, 7-Vertical tube cooler, 8-Stop valve three, 9-Stop valve four, 10-Water pump, 11-Stop valve five, 12-Isolation valve two, 13-Check valve one, 14-Regulating valve one, 15-Regulating valve two, 16-ORC turbine, 17-ORC generator, 18-ORC condenser, 19-Gas-liquid ejector, 20-Check valve two, 21-Regulating valve three, 22-Organic working fluid storage tank, 23-Stop valve six, 24-Check valve three, 25-Heat trap. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the embodiments and accompanying drawings. The illustrative embodiments and descriptions of the present invention are only used to explain the present invention and are not intended to limit the present invention.

[0033] In the following description, numerous specific details are set forth in order to provide a thorough understanding of the invention. However, it will be apparent to those skilled in the art that these specific details are not necessary to practice the invention. In other embodiments, well-known structures, circuits, materials, or methods have not been specifically described in order to avoid obscuring the invention.

[0034] Example 1

[0035] A secondary-side residual heat removal system for nuclear power plants based on jet technology-driven ORC, such as Figure 1 As shown, it includes passive natural circulation systems and organic Rankine circulation systems;

[0036] The passive natural circulation system includes a steam generator 1 and a vertical tube cooler 7 connected in sequence. The vertical tube cooler 7 condenses the steam from the steam generator 1 to form condensate. The condensate flows back into the steam generator 1 by gravity, forming a passive natural circulation loop.

[0037] The organic Rankine cycle system includes a high-efficiency heat exchanger 5, an air-cooled heat exchanger 6, an ORC turbine 16, an ORC generator 17, an ORC condenser 18, and a gas-liquid ejector 19. The high-efficiency heat exchanger 5, the air-cooled heat exchanger 6, the vertical tube cooler 7, the ORC condenser 18, and the gas-liquid ejector 19 are connected in sequence. The ORC condenser 18 is connected to the high-efficiency heat exchanger 5 through the ORC turbine 16. The ORC generator 17 is driven by the ORC turbine 16 and supplies power to the electrical equipment. The gas-liquid ejector 19 is also connected to the high-efficiency heat exchanger 5.

[0038] Among them, the steam generator 1, the high-efficiency heat exchanger 5, the air-cooled heat exchanger 6 and the vertical tube cooler 7 constitute the secondary side water circulation loop, and the high-efficiency heat exchanger 5, the ORC turbine 16, the ORC generator 17, the ORC condenser 18 and the gas-liquid ejector 19 constitute the organic Rankine cycle loop.

[0039] When the system of this invention is running, it can select to activate three circulation loops according to different situations: a passive natural circulation loop, a secondary side water circulation loop, and an organic Rankine circulation loop.

[0040] In the initial stage of a severe accident at a nuclear power plant, the secondary side water circulation loop and the organic Rankine loop are activated. The organic Rankine loop is used to absorb the heat of the high-temperature and high-pressure steam produced by the steam generator 1 to generate electricity, while providing power to electrical equipment such as the air-cooled heat exchanger 6 and water pump 10. The secondary side water circulation loop is used to cool the steam generated from the steam generator 1 on the secondary side, causing it to condense into liquid. In this stage, the ORC is driven by passive jet technology to generate electricity using the residual heat from the secondary side, forming a core decay heat removal system that combines autonomous active and passive technologies. The autonomous active residual heat removal method is based on the ORC being driven by jet technology to generate electricity using the residual heat from the secondary side. It does not rely on external power and can quickly remove heat in the initial stage of a severe accident, ensuring the safety and reliability of the system and solving the problem of limited cooling capacity of passive systems in existing technologies.

[0041] In the later stages of the accident, as decay heat decreases, the temperature and pressure of the outlet steam of steam generator 1 and the organic working fluid in the organic Rankine cycle system decrease, the organic Rankine cycle loop closes, the secondary side water circulation loop and the passive natural circulation system operate, and the system switches to passive natural circulation mode, utilizing the natural circulation of air and cooling water to remove secondary side residual heat, ensuring the safety of the nuclear power plant.

[0042] If the organic Rankine loop fails, the system will start the passive natural circulation loop, thus switching to passive natural circulation waste heat discharge mode. That is, the steam generated from the steam generator 1 will directly enter the vertical tube cooler 7 for cooling and condensation into liquid, and the condensate will then flow back into the steam generator 1.

[0043] Therefore, the system of the present invention, in the early stage of an accident, forms a core decay heat removal system that combines autonomous active and passive operation by combining the secondary side water circulation loop and the organic Rankine loop. It does not rely on external power and can quickly remove heat in the early stage of a severe accident, avoiding heat accumulation and safety hazards. In the later stage of an accident or when the organic Rankine loop fails, it can also remove heat through the secondary side water circulation loop and / or the passive natural circulation loop. The system of the present invention, through mutual backup of the active and passive systems, can achieve timely removal of secondary side residual heat under any circumstances, ensuring the safety and reliability of the system and solving the problem of limited cooling capacity of passive systems in the prior art.

[0044] Example 2

[0045] This embodiment further explains the specific connection structure of the entire system based on embodiment 1.

[0046] like Figure 1 As shown, an isolation valve 2 is installed on the outlet pipe connected to the steam generator 1 to isolate steam. The outlet pipe is connected to the vertical tube cooler 7 and the high-efficiency heat exchanger 5 via two branch pipes. A shut-off valve 3 is installed on the branch pipe connected to the vertical tube cooler 7, and a shut-off valve 4 is installed on the branch pipe connected to the high-efficiency heat exchanger 5. The steam in the pipe can be turned on or off by opening or closing the shut-off valves 3 and 4. The steam generator 1 is connected to the condensate outlet of the vertical tube cooler 7 via a return pipe. The condensate outlet of ORC condenser 18 is connected. The return pipe is equipped with isolation valve 2 12 to isolate the refluxed condensate, and check valve 13 to prevent backflow of water in steam generator 1 due to the pressure difference between steam generator 1 and the valve and gravity. A water pump 10 is installed on the return pipe. A shut-off valve 5 11 is installed in parallel with the water pump 10. A shut-off valve 4 9 is also installed on the return pipe connecting the water pump 10 and the vertical tube cooler 7. At a lower position, the water pump 10 can be used to pressurize and discharge the condensate into the steam generator 1.

[0047] The inlet and outlet of the vertical tube cooler 7 are connected to the heat sink 25 to form a loop. Cooling water is introduced into the vertical tube cooler 7 through the heat sink 25 to cool the incoming steam into condensate. The steam inlet of the vertical tube cooler 7 is connected to the outlet of the steam generator 1 and the outlet of the air-cooled heat exchanger 6. The condensate outlet of the vertical tube cooler 7 is connected to the ORC condenser 18 and the water pump 10. The condensate leaving the outlet of the vertical tube cooler 7 has two paths. One path is that in the passive natural circulation, the condensate flows directly back into the steam generator 1 by gravity. The other path is that in the organic Rankine cycle, the condensate needs to flow into the ORC condenser 18 to cool the organic steam from the ORC turbine 16 into subcooled liquid. After that, the condensate flows out from the condensate outlet of the ORC condenser 18 and flows back into the steam generator 1 through the water pump 10.

[0048] The organic working fluid inlet of the high-efficiency heat exchanger 5 is connected to the organic working fluid storage tank 22, the organic vapor outlet of the high-efficiency heat exchanger 5 is connected to the ORC turbine 16 and the gas-liquid ejector 19, and the vapor outlet of the high-efficiency heat exchanger 5 is connected to the inlet of the air-cooled heat exchanger 6. Inside the high-efficiency heat exchanger 5, an organic working fluid is introduced to cool the steam from the steam generator 1. After absorbing heat, the organic working fluid becomes organic vapor and is discharged from the organic vapor outlet of the high-efficiency heat exchanger 5. The steam from the steam generator 1 is cooled and exits from the high-efficiency heat exchanger. Steam is discharged from the outlet of 5; wherein, the connecting pipe between the organic working fluid storage tank 22 and the high-efficiency heat exchanger 5 is equipped with a shut-off valve 6 23 and a check valve 3 24, and the liquid inlet pipe of the organic working fluid storage tank 22 is equipped with a regulating valve 3 21. The shut-off valve 6 23 opens or closes to realize the opening and closing of the organic working fluid in the pipe. The check valve 3 24 can prevent the backflow of organic working fluid caused by the pressure in the organic vapor generator being higher than the pressure before the valve. The regulating valve 3 21 can regulate the liquid flow rate entering the organic working fluid storage tank 22.

[0049] The organic vapor inlet of the ORC turbine 16 is connected to the organic vapor outlet of the high-efficiency heat exchanger 5, and the organic vapor outlet of the ORC turbine 16 is connected to the ORC condenser 18. The ORC condenser 18 has a condensate inlet and a condensate outlet for the condensate from the vertical tube cooler 7 to flow in and out. A shut-off valve 8 is installed on the pipe connecting the condensate inlet of the ORC condenser 18 and the vertical tube cooler 7. The ORC condenser 18 also has an organic vapor inlet and a subcooled liquid outlet. The organic vapor inlet is used to introduce the organic vapor after the ORC turbine 16 expands and does work. The organic vapor is further cooled by the condensate to form subcooled liquid. The subcooled liquid outlet is used to discharge the subcooled liquid and return it to the steam generator 1 through the water pump 10.

[0050] The organic vapor inlet of the gas-liquid ejector 19 is connected to the organic vapor outlet of the high-efficiency heat exchanger 5. The gas-liquid ejector 19 is also connected to the subcooled liquid outlet of the ORC condenser 18. The outlet of the gas-liquid ejector 19 is connected to the high-efficiency heat exchanger 5. This connection structure is designed to facilitate a portion of the organic vapor from the high-efficiency heat exchanger 5 to enter the gas-liquid ejector 19, be drawn into the subcooled liquid, and then flow back into the high-efficiency heat exchanger 5, thereby forming an organic Rankine cycle loop.

[0051] A regulating valve 14 is installed on the connecting pipe between the inlet of the gas-liquid ejector 19 and the high-efficiency heat exchanger 5 to automatically adjust the opening degree according to the preset temperature and pressure change law of the organic working fluid. A check valve 20 is installed on the connecting pipe between the outlet of the gas-liquid ejector 19 and the high-efficiency heat exchanger 5 to prevent the backflow of the organic working fluid caused by the pressure in the organic vapor generator being higher than the pressure before the valve. A regulating valve 15 is installed on the connecting pipe between the ORC turbine 16 and the high-efficiency heat exchanger 5 to automatically adjust the opening degree according to the preset temperature and pressure change law of the organic working fluid.

[0052] Example 3

[0053] This embodiment further explains the operation flow of the system of the present invention based on embodiment 2.

[0054] When the nuclear power plant is operating normally, all valves in all loops of this system are closed. The vertical tube cooler 7 and the organic working fluid storage tank 22 are pre-filled with cooling water and organic working fluid at a certain liquid level, respectively.

[0055] (1) When a serious accident occurs at a nuclear power plant and the reactor shuts down, heat is discharged through a combination of autonomous and passive methods.

[0056] Isolation valve 1 (2), stop valve 2 (4), stop valve 3 (8), isolation valve 2 (12), stop valve 6 (23), regulating valve 1 (14), and regulating valve 2 (15) automatically open when power is off. The cooling water in the vertical pipe cooler 7 flows into the steam generator 1 under the action of gravity, replenishing the water that evaporates away by the primary side coolant in the steam generator 1.

[0057] After the water in steam generator 1 absorbs heat to form high-temperature and high-pressure steam, it rises along the pipeline and enters the organic steam generator through shut-off valve 24. At the same time, the organic working medium in the organic working medium storage tank 22 flows into the organic steam generator under the action of gravity. After absorbing the heat from the high-temperature and high-pressure steam in steam generator 1, it is transformed into high-temperature and high-pressure organic steam. At this time, the high-temperature and high-pressure steam in steam generator 1 is cooled down.

[0058] After the high-temperature and high-pressure steam from the steam generator 1 is cooled down, it enters the air-cooled heat exchanger 6 for further cooling, which can effectively prevent the water temperature entering the vertical tube cooler 7 from being too high and avoid water evaporation in the tubes of the vertical tube cooler 7, thus avoiding water hammer. The water coming out of the air-cooled heat exchanger 6 enters the vertical tube cooler 7 and is condensed by the cooling water to form condensate. The condensate flows back along the pipe under the action of gravity, and after being pressurized by the water pump 10 at a lower position, it enters the steam generator 1 to form a secondary side water circulation loop.

[0059] After absorbing heat, the organic working fluid forms high-temperature and high-pressure organic vapor, which is then diverted. Part of the high-temperature and high-pressure organic vapor enters the ORC turbine 16 to expand and do work, driving the ORC generator 17 to generate electricity for the air-cooled heat exchanger 6 and the water pump 10. After the ORC turbine 16 expands and does work, the high-temperature and high-pressure organic vapor is converted into low-temperature and low-pressure organic vapor and discharged into the ORC condenser 18. The vertical tube cooler 7 introduces condensate into the ORC condenser 18 and further cools the low-temperature and low-pressure organic vapor after the ORC turbine 16 expands and does work, forming a subcooled liquid. Another part of the high-temperature and high-pressure organic vapor is used as a diverting working fluid and enters the gas-liquid ejector 19. The subcooled liquid is drawn in and mixed by the high-speed organic vapor in the gas-liquid ejector 19 and then flows back into the organic vapor generator in liquid form, forming an organic Rankine loop.

[0060] The power generated by ORC generator 17 can provide backup power for air-cooled heat exchanger 6, water pump 10, and the opening and closing of various valves.

[0061] Therefore, in the event of a severe accident at a nuclear power plant, the secondary water circulation loop and the organic Rankine loop are combined to form a passive and autonomous active operating mode. This mode can quickly dissipate heat in the early stages of a severe accident without relying on external power, ensuring the safety and reliability of the system and solving the problem of limited cooling capacity of passive systems in existing technologies.

[0062] (2) When the organic Rankine cycle system fails, the passive natural circulation system is started to discharge the waste heat in a passive natural circulation manner.

[0063] Gate valve 1 (3), gate valve 4 (9), and gate valve 5 (11) automatically open and remain open, while gate valve 2 (4) and gate valve 3 (8) automatically close and remain closed. Water in steam generator 1 absorbs heat to form high-temperature and high-pressure steam, which then rises along the pipeline and directly enters vertical pipe cooler 7. After being cooled by cooling water, it condenses into condensate and flows back into steam generator 1 under gravity, forming a natural circulation. It operates in a completely passive mode to ensure the normal discharge of secondary waste heat.

[0064] (3) When a serious accident occurs and the ORC loop is operating normally, as the decay heat decreases, the temperature and pressure of the outlet steam of steam generator 1 and the organic working fluid in the organic Rankine cycle system decrease, the organic Rankine cycle loop is closed, and the secondary side water cycle loop and the passive natural circulation system are in operation.

[0065] According to the preset organic working fluid temperature and pressure threshold, shut-off valve 1 (3), shut-off valve 4 (9), and shut-off valve 5 (11) automatically open and remain open, while shut-off valve 3 (8) automatically closes and remains open. The high-temperature and high-pressure steam from the steam generator 1 continues to pass through the organic steam generator and then enters the air-cooled heat exchanger 6 for cooling by natural air circulation. After that, it enters the vertical tube cooler 7 and is cooled and condensed into condensate by cooling water from the heat sink 25. Under the action of gravity, it flows back into the steam generator 1 along the pipe, forming a natural circulation. It operates in a completely passive mode and continues to discharge the secondary side waste heat.

[0066] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A secondary-side residual heat removal system for nuclear power plants based on jet-driven ORC (Organic Residual Heat Collection), characterized in that, Including passive natural circulation systems and organic Rankine circulation systems; The passive natural circulation system includes a steam generator (1) and a vertical tube cooler (7) connected in sequence. The vertical tube cooler (7) condenses the steam from the steam generator (1) to form condensate. The condensate flows back into the steam generator (1) by gravity, forming a passive natural circulation loop. The organic Rankine cycle system includes a high-efficiency heat exchanger (5), an air-cooled heat exchanger (6), an ORC turbine (16), an ORC generator (17), an ORC condenser (18), and a gas-liquid ejector (19). The high-efficiency heat exchanger (5), the air-cooled heat exchanger (6), the vertical tube cooler (7), the ORC condenser (18), and the gas-liquid ejector (19) are connected in sequence. The ORC condenser (18) is connected to the high-efficiency heat exchanger (5) through the ORC turbine (16). The ORC generator (17) is driven by the ORC turbine (16) and supplies power to electrical equipment. The gas-liquid ejector (19) is also connected to the high-efficiency heat exchanger (5). Among them, the steam generator (1), the high-efficiency heat exchanger (5), the air-cooled heat exchanger (6) and the vertical tube cooler (7) constitute the secondary side water circulation loop, and the high-efficiency heat exchanger (5), the ORC turbine (16), the ORC generator (17), the ORC condenser (18) and the gas-liquid ejector (19) constitute the organic Rankine cycle loop.

2. The secondary side residual heat removal system of a nuclear power plant based on jet technology-driven ORC as described in claim 1, characterized in that: (1) When a serious accident occurs at a nuclear power plant, resulting in reactor shutdown and power outage. Organic working fluid is introduced into the high-efficiency heat exchanger (5) to cool the steam from the steam generator (1). The cooled steam is then introduced into the air-cooled heat exchanger (6) and the vertical tube cooler (7) to form condensate. The condensate flows back into the steam generator (1) by gravity to form a secondary side water circulation loop. After heat exchange, the organic working fluid forms organic vapor. Part of the organic vapor enters the ORC turbine (16) to expand and do work, and drives the ORC generator (17) to generate electricity to power the electrical equipment. The vertical tube cooler (7) introduces condensate into the ORC condenser (18) and cools the organic vapor after it expands and does work in the ORC turbine (16) to form subcooled liquid. Another part of the organic vapor enters the gas-liquid ejector (19) and is drawn into the subcooled liquid before flowing back into the high-efficiency heat exchanger (5) to form an organic Rankine loop. (2) When the organic Rankine cycle system fails, the passive natural cycle system is activated; (3) When a serious accident occurs and the ORC loop is operating normally, as the decay heat decreases, the outlet steam of the steam generator (1) and the temperature and pressure of the organic working fluid in the organic Rankine cycle system decrease, the organic Rankine cycle loop is closed, and the secondary side water cycle loop and the passive natural circulation system are in operation.

3. A nuclear power plant secondary-side residual heat removal system based on jet technology-driven ORC according to claim 1, characterized in that, An isolation valve (2) is installed on the outlet pipe connected to the steam generator (1), and an isolation valve (12) and a check valve (13) are also installed on the return pipe connected to the steam generator (1).

4. A nuclear power plant secondary-side residual heat removal system based on jet technology-driven ORC according to claim 1, characterized in that, The inlet and outlet of the vertical tube cooler (7) are connected to the heat sink (25) to form a loop.

5. A nuclear power plant secondary-side residual heat removal system based on jet technology-driven ORC according to claim 1, characterized in that, The steam inlet of the vertical tube cooler (7) is connected to the outlet of the steam generator (1) and the outlet of the air-cooled heat exchanger (6), and the condensate outlet of the vertical tube cooler (7) is connected to the ORC condenser (18) and the water pump (10).

6. A nuclear power plant secondary-side residual heat removal system based on jet technology-driven ORC according to claim 1, characterized in that, The organic working fluid inlet of the high-efficiency heat exchanger (5) is connected to the organic working fluid storage tank (22), the organic vapor outlet of the high-efficiency heat exchanger (5) is connected to the ORC turbine (16) and the gas-liquid ejector (19), and the vapor outlet of the high-efficiency heat exchanger (5) is connected to the inlet of the air-cooled heat exchanger (6).

7. A nuclear power plant secondary-side residual heat removal system based on jet technology-driven ORC according to claim 6, characterized in that, The organic working fluid storage tank (22) is connected to the high-efficiency heat exchanger (5) by a shut-off valve six (23) and a check valve three (24), and the organic working fluid storage tank (22) is connected to a regulating valve three (21).

8. A nuclear power plant secondary-side residual heat removal system based on jet technology-driven ORC according to claim 1, characterized in that, The organic vapor inlet of the ORC turbine (16) is connected to the organic vapor outlet of the high-efficiency heat exchanger (5), and the organic vapor outlet of the ORC turbine (16) is connected to the ORC condenser (18).

9. A nuclear power plant secondary-side residual heat removal system based on jet technology-driven ORC according to claim 1, characterized in that, The organic vapor inlet of the gas-liquid ejector (19) is connected to the organic vapor outlet of the high-efficiency heat exchanger (5), and the gas-liquid ejector (19) is also connected to the subcooled liquid outlet of the ORC condenser (18).

10. A nuclear power plant secondary-side residual heat removal system based on jet technology-driven ORC according to claim 1, characterized in that, A regulating valve (14) is provided on the connecting pipe between the inlet of the gas-liquid ejector (19) and the high-efficiency heat exchanger (5), a check valve (20) is provided on the connecting pipe between the outlet of the gas-liquid ejector (19) and the high-efficiency heat exchanger (5), and a regulating valve (15) is provided on the connecting pipe between the ORC turbine (16) and the high-efficiency heat exchanger (5).

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