Supercritical carbon dioxide cycle power generation control system and method for metal cooled reactor

Abstract

The application discloses a kind of metal cooling reactor supercritical carbon dioxide cycle power generation control system and method, the system includes intermediate heat exchanger, circulating pump, reactor, pressure reducing valve, turbine, regenerator, compressor, storage tank inlet valve, storage tank, storage tank exhaust valve, cooler, buffer tank, water pump, pool, generator and control module.Control module includes turbine inlet temperature and pressure control, compressor inlet temperature and pressure control, reactor inlet temperature control, speed control and flow control module, is respectively used for accurately regulating and controlling turbine inlet condition, compressor operating state, reactor operating temperature, turbine and compressor working medium flow and the working medium flow of compressor outlet to regenerator hot side outlet.By fine control the working parameters of each component, the load change of partition control system is realized, and wide load, efficient, stable operation of supercritical carbon dioxide cycle power generation process is realized.

Description

Technical Field

[0001] This invention belongs to the field of novel cycle system control technology, and relates to a control system and method for supercritical carbon dioxide cycle power generation in a metal-cooled reactor. Background Technology

[0002] With the increasing global demand for efficient, clean, and flexible energy solutions, liquid metal-cooled reactors and supercritical carbon dioxide (CO2) are becoming increasingly popular. The integration of cyclic power generation systems is gradually becoming a research hotspot. This cutting-edge technology combination has significant advantages in improving energy conversion efficiency, reducing carbon emissions, and enhancing system flexibility, especially in special applications with extremely high requirements for safety, response speed, and wide-load operation capabilities, such as nuclear submarine propulsion systems, where its potential is particularly prominent.

[0003] Nuclear submarines place extremely stringent requirements on the compactness, reliability, and efficiency of their propulsion systems. Traditional power generation systems often struggle to meet these conditions simultaneously, especially within the space-constrained environment of a nuclear submarine. Therefore, a supercritical carbon dioxide cycle power generation system employing a turbine-compressor coaxial arrangement has become an ideal solution. However, this design requires the turbine speed to change synchronously with the compressor speed, making it difficult to simultaneously meet the optimal speed requirements of both under varying loads, temperatures, and pressures. This results in poor adaptability of the unit under complex and variable operating conditions. Furthermore, to ensure the stability and reliability of synchronous regulation, the unit's operating range may be limited, making it difficult to adapt to the load demands of a nuclear submarine under different operating conditions. Summary of the Invention

[0004] The purpose of this invention is to solve the technical problem of unstable system operation caused by complex operating conditions in the prior art, and to provide a control system and method for supercritical carbon dioxide cycle power generation in metal-cooled reactors.

[0005] To achieve the above objectives, the present invention employs the following technical solution:

[0006] The first aspect of the present invention provides a supercritical carbon dioxide cycle power generation control system for a metal-cooled reactor, comprising an intermediate heat exchanger, a reactor, a turbine, a regenerator, a cooler, a compressor, a storage tank, a generator, and a control module;

[0007] The hot-side outlet of the intermediate heat exchanger is connected to the reactor inlet, and the hot-side inlet of the intermediate heat exchanger is connected to the reactor outlet.

[0008] The cold-side outlet of the intermediate heat exchanger is connected to the turbine inlet; the turbine outlet is connected to the hot-side inlet of the regenerator; the hot-side outlet of the regenerator is connected to the hot-side inlet of the cooler; the hot-side outlet of the cooler is connected to the compressor inlet; the compressor outlet is connected to both the hot-side outlet and the cold-side inlet of the regenerator; the cold-side outlet of the regenerator is connected to the cold-side inlet of the intermediate heat exchanger; a storage tank is provided between the compressor outlet and the hot-side outlet connected to the regenerator.

[0009] The turbine, generator, and compressor are arranged coaxially in sequence.

[0010] The control module includes:

[0011] The core inlet temperature control module is used to control the reactor outlet temperature.

[0012] Turbine inlet temperature control module, used to control turbine inlet temperature;

[0013] Turbine inlet pressure control module, used to control turbine inlet pressure;

[0014] The compressor inlet temperature control module is used to control the compressor inlet temperature.

[0015] The compressor inlet pressure control module is used to control the compressor inlet pressure.

[0016] The reactor inlet temperature control module is used to control the reactor inlet temperature.

[0017] The speed control module is used to control the working fluid flow rate of the turbine and compressor;

[0018] The flow control module is used to control the flow rate of the working fluid from the compressor outlet to the storage tank and from the storage tank to the hot side inlet of the cooler.

[0019] Furthermore, a circulating pump is installed between the hot-side outlet of the intermediate heat exchanger and the reactor inlet, and the turbine inlet temperature control module controls the turbine inlet temperature by adjusting the speed of the circulating pump.

[0020] Furthermore, a pressure-reducing valve is provided at the inlet of the turbine, and the turbine inlet pressure control module controls the turbine inlet pressure by adjusting the opening of the pressure-reducing valve.

[0021] Furthermore, a buffer tank is provided between the hot-side outlet of the cooler and the compressor inlet.

[0022] Furthermore, the cooler's cold-side outlet is connected to a water tank; the water tank is connected to the cooler's cold-side inlet.

[0023] Furthermore, a water pump is installed between the water tank and the cold-side inlet of the cooler.

[0024] Furthermore, the compressor inlet temperature control module controls the compressor inlet temperature by adjusting the speed of the water pump.

[0025] Furthermore, the storage tank is equipped with an inlet valve at the inlet and an outlet valve at the outlet. The compressor inlet pressure control module controls the compressor inlet pressure by adjusting the opening and closing of the inlet valve and the outlet valve.

[0026] Furthermore, the flow control module controls the turbine inlet flow and compressor inlet flow by adjusting the opening of the intake valve and exhaust valve.

[0027] A second aspect of the present invention provides a method for controlling supercritical carbon dioxide cycle power generation in a metal-cooled reactor, comprising the following steps:

[0028] In the medium-to-high load range, the load is adjusted using speed control, specifically as follows:

[0029] Adjust the turbine's rotational speed to match the speed at which the current flow rate has the maximum entropy efficiency.

[0030] Reducing the rotational speed causes a linear change in the working fluid flow rate. By controlling the rotational speed of the circulating pump, the flow rate of the coolant in the reactor is adjusted to maintain a constant turbine inlet temperature.

[0031] Adjust the opening and closing status of the inlet and outlet valves of the storage tank to maintain a constant compressor inlet pressure;

[0032] The pump speed is controlled to regulate the cooling water flow rate to keep the compressor inlet temperature constant. The depth of the reactor control rods inserted into the reactor core is adjusted to make the reactor inlet temperature decrease slightly and then increase slightly.

[0033] In the low-load area, the turbine inlet pressure control method can be used to regulate the load, specifically as follows:

[0034] Keep the turbine at a low speed and reduce the turbine inlet pressure by decreasing the opening of the pressure relief valve in front of the turbine.

[0035] Adjusting the opening of the inlet and outlet valves of the storage tank controls the linear decrease of the working fluid flow rate within the system.

[0036] Adjusting the speed of the circulating pump changes the coolant flow rate of the reactor to maintain a constant turbine inlet temperature;

[0037] Adjust the opening and closing status of the inlet valve and outlet valve of the storage tank to maintain a constant compressor inlet pressure;

[0038] Adjusting the pump speed changes the cooling water flow rate to maintain a constant compressor inlet temperature, while adjusting the depth of the reactor control rods inserted into the reactor core increases the reactor inlet temperature.

[0039] Compared with the prior art, the present invention has the following beneficial effects:

[0040] This invention discloses a supercritical carbon dioxide cycle power generation control system for a metal-cooled reactor. The system incorporates a turbine inlet temperature control module and a turbine inlet pressure control module, enabling precise adjustment of turbine operating conditions, optimizing performance, and extending service life. Simultaneously, the compressor inlet temperature and pressure control module ensures stable compressor operation, preventing malfunctions caused by compressor surge. The speed control module, by adjusting the turbine and compressor speeds, achieves precise control of the working fluid flow rate and turbine performance. This function not only helps maintain pressure balance within the system but also allows for flexible adjustment of power generation according to actual needs, improving the system's response speed and flexibility. The reactor inlet temperature control module ensures safe and stable reactor operation, effectively preventing decreased reaction efficiency or safety hazards caused by excessively high or low temperatures. The flow control module allows the system to flexibly adjust the working fluid flow rate from the compressor outlet to the storage tank inlet and from the storage tank outlet to the cooler hot-side inlet based on external load changes or maintenance requirements, thereby altering the main cycle flow rate. This function not only improves the system's adaptability and flexibility but also helps optimize energy distribution and reduce unnecessary energy consumption.

[0041] Furthermore, the supercritical carbon dioxide cycle power generation control method for metal-cooled reactors of the present invention ensures wide-load operation of the power generation system by controlling the load changes of the system in a zoned manner. By using a speed control method in the medium-to-high load region, employing a speed control function with flow rate as the variable, the system maintains efficient turbine work, achieving efficient power generation in the medium-to-high load region. By using a turbine inlet pressure control method in the low load region, the inefficiency problem of the turbine bypass control method is solved, and the safety risk of coolant solidification associated with the turbine inlet temperature control method is avoided, achieving efficient power generation in the low load region.

[0042] Furthermore, the supercritical carbon dioxide cycle power generation control method for metal-cooled reactors of this invention ensures that the turbine operates at maximum isentropic efficiency by precisely adjusting the turbine's rotational speed to achieve optimal matching with the current flow rate, thereby improving the energy conversion efficiency of the entire cycle system. Adjusting the turbine rotational speed within the range of 40%-110% of rated speed achieves linear changes in the working fluid flow rate, which not only enhances the system's response speed but also ensures the accuracy and stability of load regulation. Maintaining a constant turbine inlet temperature by adjusting the circulating pump speed and maintaining stable compressor inlet pressure by adjusting the inlet and outlet valves of the storage tank effectively avoids the impact of temperature and pressure fluctuations on system performance. Adjusting the insertion depth of the reactor control rods allows for precise control of the reactor inlet temperature, further enhancing the system's adaptability and flexibility to load changes. In the low-load region, maintaining the turbine at 40% of its rated speed and controlling the turbine inlet pressure by adjusting the opening of the turbine-front pressure-reducing valve simplifies the control logic and reduces system instability under low load conditions. By adjusting the opening of the inlet and outlet valves of the storage tank, a linear decrease in the working fluid flow rate within the system was achieved, ensuring stable system operation under low load. Similarly, by adjusting the circulating pump speed and water pump speed to maintain constant turbine inlet temperature and compressor inlet temperature respectively, and by adjusting the storage tank valves to maintain stable compressor inlet pressure, the system stability under low load was further enhanced. In the low-load region, turbine bypass control and turbine inlet temperature control methods are not used. This is mainly due to the following factors:

[0043] Turbine bypass control regulates load by adjusting the flow ratio between the main and branch lines by controlling the opening of the turbine bypass valve. While this method offers rapid load regulation, the constant working fluid flow rate leads to low turbine speed and entropy efficiency in the low-load region, resulting in a significant decrease in turbine work per unit area. Simultaneously, this method increases the coolant temperature within the reactor, thereby increasing reactor power. These changes result in a lower system power generation efficiency compared to the turbine inlet pressure control method.

[0044] Turbine inlet temperature control adjusts the load by controlling the speed of the circulating pump to change the reactor coolant flow rate and thus the turbine inlet temperature. However, this method leads to drastic changes in reactor coolant temperature, posing a thermal shock risk to the core equipment of the power generation system. Under low load conditions, it may cause the reactor inlet temperature to drop to the freezing point, creating a significant hazard to reactor operational safety.

[0045] The method of this invention not only enhances the system's response speed and ensures power generation efficiency, but also guarantees the accuracy and stability of load regulation. Attached Figure Description

[0046] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0047] Figure 1 This is a diagram of the supercritical carbon dioxide cycle power generation control system for the metal-cooled reactor of the present invention.

[0048] Wherein: 1-Intermediate heat exchanger; 2-Circulating pump; 3-Reactor; 4-Pressure reduction valve; 5-Turbine; 6-Regenerator; 7-Cooler; 8-Buffer tank; 9-Compressor; 10-Inlet valve; 11-Storage tank; 12-Exhaust valve; 13-Water pump; 14-Water pool; 15-Generator. Detailed Implementation

[0049] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and marked in the accompanying drawings can generally be arranged and designed in various different configurations.

[0050] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0051] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0052] In the description of the embodiments of the present invention, it should be noted that if terms such as "upper," "lower," "horizontal," or "inner" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of the invention is in use, they are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. Furthermore, terms such as "first" and "second" are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0053] Furthermore, the use of the term "horizontal" does not imply that the component must be absolutely horizontal, but rather that it can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0054] In the description of the embodiments of the present invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the present invention according to the specific circumstances.

[0055] The present invention will now be described in further detail with reference to the accompanying drawings:

[0056] See Figure 1 This invention discloses a supercritical carbon dioxide cycle power generation control system for a metal-cooled reactor, comprising: an intermediate heat exchanger 1, a circulating pump 2, a reactor 3, a pressure reducing valve 4, a turbine 5, a regenerator 6, a cooler 7, a buffer tank 8, a compressor 9, a storage tank inlet valve 10, a storage tank 11, a storage tank exhaust valve 12, a water pump 13, a water pool 14, a generator 15, and a control module.

[0057] The hot side outlet of the intermediate heat exchanger 1 is connected to the inlet of the reactor 3, and the hot side inlet of the intermediate heat exchanger 1 is connected to the outlet of the reactor 3. As a heat exchange device, the intermediate heat exchanger 1 is used for heat transfer of the reactor coolant on its hot side and for heating the working medium (supercritical carbon dioxide) entering the turbine on its cold side.

[0058] The cold-side outlet of the intermediate heat exchanger 1 is connected to the inlet of turbine 5; the outlet of turbine 5 is connected to the hot-side inlet of regenerator 6; the hot-side outlet of regenerator 6 is connected to the inlet of compressor 9; the outlet of compressor 9 is connected to both the hot-side inlet of cooler 7 and the cold-side inlet of regenerator 6; the cold-side outlet of regenerator 6 is connected to the cold-side inlet of intermediate heat exchanger 1; a circulating pump 2 is installed between the hot-side outlet of intermediate heat exchanger 1 and the inlet of reactor 3; a pressure-reducing valve 4 is installed at the front end of the inlet of turbine 5; a buffer tank 8 is installed between the hot-side outlet of regenerator 6 and the inlet of compressor 9. A cooler 7 is installed between the hot-side outlet of regenerator 6 and buffer tank 8; the hot-side outlet of regenerator 6 is connected to the hot-side inlet of cooler 7; the hot-side outlet of cooler 7 is connected to buffer tank 8. A water tank 14 is connected to the cold-side outlet of cooler 7; the water tank 14 is connected to the cold-side inlet of cooler 7. A water pump 13 is installed between the water tank 14 and the cold side inlet of the cooler 7, and a storage tank 11 is installed between the outlet of the compressor 9 and the hot side inlet of the cooler. The inlet of the storage tank 11 is equipped with an air inlet valve 10, and the outlet is equipped with an exhaust valve 12; the turbine 5, the generator 15, and the compressor 9 are arranged coaxially in sequence.

[0059] The control module includes:

[0060] The core inlet temperature control module is used to control the core inlet temperature of reactor 3 by adjusting the depth of the control rod inserted into the core.

[0061] The turbine inlet temperature control module is used to control the inlet temperature of turbine 5 by adjusting the speed of circulating pump 2;

[0062] The turbine inlet pressure control module is used to control the turbine inlet pressure by adjusting the opening of the pressure reducing valve 4;

[0063] The compressor inlet temperature control module is used to control the inlet temperature of the compressor 9 by adjusting the speed of the water pump 13;

[0064] The compressor inlet pressure control module is used to control the compressor 9 inlet pressure by adjusting the opening and closing of the intake valve 10 and the exhaust valve 12;

[0065] The reactor inlet temperature control module is used to control the reactor inlet temperature by adjusting the depth of the control rods inserted into the reactor core in reactor 3.

[0066] The speed control module is used to control the working fluid flow of turbine 5 and compressor 9 by adjusting the speed of turbine 5 and compressor 9;

[0067] The flow control module is used to control the working fluid flow rate from the compressor 9 outlet to the storage tank 11 inlet, or from the storage tank 11 outlet to the cooler 7 hot side inlet, by adjusting the opening of the intake valve 10 and the exhaust valve 12.

[0068] The working process / working principle of this invention is as follows:

[0069] Low-pressure, low-temperature supercritical carbon dioxide enters compressor 9 and is compressed into a high-pressure, low-temperature fluid. It then sequentially enters the cold side of regenerator 6 and the cold side of intermediate heat exchanger 1, absorbing heat and transforming into a high-pressure, high-temperature fluid. This fluid then enters pressure-reducing valve 4. After pressure reduction, the working fluid enters turbine 5, rapidly expands, and drives turbine 5 to rotate. The rotation of turbine 5 drives generator 15 to generate electricity via a mechanical transmission device, thus converting thermal energy into electrical energy. The low-pressure, high-temperature fluid, after performing work, enters the hot side of regenerator 6 and the hot side of precooler 7 to cool back to its initial state, preparing for the next cycle.

[0070] The inlet pressure of turbine 5 is controlled by adjusting the opening of pressure reducing valve 4 according to the power load demand. Decreasing the opening of pressure reducing valve 4 increases the pressure drop through pressure reducing valve 4, thereby reducing the inlet pressure of turbine 5; increasing the opening of pressure reducing valve 4 decreases the pressure drop through pressure reducing valve 4, thereby increasing the inlet pressure of turbine 5.

[0071] Based on the power load demand, the working fluid flow rate of the system is controlled by adjusting the speeds of the coaxial turbine 5 and compressor 9. Decreasing the speed reduces the working fluid flow rate within the system, while increasing the speed increases the working fluid flow rate.

[0072] Based on the power load demand, the flow rate of the working fluid in the system is controlled by adjusting the opening of the inlet valve 10 and the exhaust valve 12 of the storage tank 11. Decreasing the opening of the inlet valve 10 and increasing the opening of the exhaust valve 12 of the storage tank 11 increases the flow rate of the main circulating working fluid by discharging high-density working fluid into the system; increasing the opening of the inlet valve 10 and decreasing the opening of the exhaust valve 12 decreases the flow rate of the main circulating working fluid by collecting low-density working fluid into the storage tank 11.

[0073] The inlet pressure of compressor 9 is controlled by adjusting the opening and closing states of the storage tank inlet valve 10 and the exhaust valve 12 according to the power load demand. Opening the storage tank inlet valve 10 and closing the storage tank exhaust valve 12 increases the inlet pressure of compressor 9; closing the storage tank inlet valve 10 and opening the storage tank exhaust valve 12 decreases the inlet pressure of compressor 9.

[0074] The reactor inlet temperature (R3) is controlled by adjusting the height of the control rods inserted into the reactor core, based on power load requirements. Increasing the control rod height increases the R3 inlet temperature; decreasing the control rod height decreases the R3 inlet temperature.

[0075] Based on the power load demand, the flow rate of cooling water in the water tank 14 is changed by adjusting the speed of water pump 13, thereby controlling the inlet temperature of compressor 9. Decreasing the speed of water pump 13 reduces the flow rate of cooling water; increasing the speed of water pump 13 increases the flow rate of cooling water.

[0076] Based on the power load demand, the coolant flow rate in the reactor core of reactor 3 is changed by adjusting the speed of circulating pump 2, thereby controlling the inlet temperature of turbine 5. Decreasing the speed of circulating pump 2 reduces the coolant flow rate; increasing the speed of circulating pump 2 increases the coolant flow rate.

[0077] Based on the power load demand, the flow rate of the working fluid from the compressor outlet to the tank inlet and the mass of the working fluid from the tank outlet to the hot side inlet of the cooler are controlled by adjusting the opening of the tank inlet valve 10 and the exhaust valve 12, respectively. Increasing the opening of the inlet valve 10 reduces the flow rate into the turbine 5 inlet; decreasing the opening of the inlet valve 10 increases the flow rate into the turbine 5 inlet. Increasing the opening of the exhaust valve 12 increases the flow rate into the compressor 9 inlet, and decreasing the opening of the exhaust valve 12 decreases the flow rate into the compressor 9 inlet.

[0078] This invention provides a method for controlling supercritical carbon dioxide cycle power generation in a metal-cooled reactor, comprising:

[0079] This invention can achieve full load regulation from 0% to 100% through load zoning control.

[0080] In the medium-to-high load range, the load is regulated by speed control. Specifically, the speed of turbine 5 is matched with the speed that maximizes the entropy efficiency of the turbine at the current flow rate, ensuring efficient work by turbine 5 and thus achieving high system power generation efficiency. Controlling the speed within the 40%-110% rated range prevents resonance problems and unstable unit operation. At this time, the working fluid flow rate is linearly changed by adjusting the speed; the coolant flow rate in reactor 3 is adjusted by controlling the speed of circulating pump 2 to maintain a constant inlet temperature of turbine 5; the inlet pressure of compressor 9 is maintained constant by adjusting the opening and closing states of inlet valve 10 and exhaust valve 12 of storage tank 11; the inlet temperature of compressor 9 is maintained constant by controlling the speed of water pump 13 to adjust the cooling water flow rate; and the inlet temperature of reactor 3 is adjusted by adjusting the depth of the control rods inserted into the reactor core.

[0081] In the low-load region, the turbine inlet pressure control method can be used to regulate the load. Maintaining turbine 5 at 40% speed, the turbine inlet pressure is reduced by decreasing the opening of the pressure-reducing valve 4 before turbine 5. The working fluid flow rate in the system is linearly reduced by adjusting the opening of the inlet valve 10 and exhaust valve 12 of the storage tank 11. The inlet temperature of turbine 5 is maintained constant by adjusting the speed of the circulating pump 2 to change the coolant flow rate of reactor 3. The inlet pressure of compressor 9 is maintained constant by adjusting the opening and closing states of the inlet valve 10 and exhaust valve 12 of the storage tank 11. The inlet temperature of compressor 9 is maintained constant by adjusting the speed of the water pump 13 to change the cooling water flow rate. The inlet temperature of reactor 3 is increased by raising the height of the control rods inserted into the reactor core.

[0082] One embodiment of the present invention uses a load reduction method based on a metal-cooled reactor supercritical carbon dioxide cycle power generation control method, as follows:

[0083] Based on the relationship curves between efficiency, flow rate, and speed in the turbine performance curve spectrum, obtain the turbine speed data points corresponding to the highest entropy efficiency of the turbine at each flow rate. Fit the data points to establish the optimal speed control function RS = f (m), and input this function as the control signal into the speed control module.

[0084] Starting from 100% load, the load is reduced using speed control: the turbine and compressor speeds are controlled to decrease from 100% rated speed based on the RS = f(m) function, causing the working fluid flow rate in the system to decrease linearly; the circulating pump speed is reduced to decrease the coolant flow rate in the reactor, maintaining the turbine inlet temperature at 480°C; the opening and closing status of the tank inlet and outlet valves are controlled to maintain the compressor inlet pressure at 7.6MPa; the water pump speed is reduced to decrease the cooling water flow rate, maintaining the compressor inlet temperature at 32°C; the height of the control rods inserted into the reactor core is first slowly reduced and then slowly increased to increase the coolant inlet temperature.

[0085] When the speed drops to 40% of the rated speed, the load is reduced to 38%, while the speed remains unchanged.

[0086] To reduce load, the following methods were employed: The pressure-reducing valve opening was decreased to increase the pressure drop across it, thus lowering the turbine inlet pressure; the tank inlet valve opening was increased while the exhaust valve opening was decreased to linearly reduce the working fluid flow rate; the circulating pump speed was reduced to decrease the coolant flow rate, maintaining the turbine inlet temperature at 480°C; the tank inlet and exhaust valves were adjusted to maintain the compressor inlet pressure at 7.6 MPa; the water pump speed was reduced to decrease the cooling water flow rate, maintaining the compressor inlet temperature at 32°C; and the control rod insertion height into the reactor core was slowly increased to raise the coolant inlet temperature. This continued until the load dropped to 0%.

[0087] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. 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 control method for supercritical carbon dioxide cycle power generation in a metal-cooled reactor, based on a supercritical carbon dioxide cycle power generation control system for a metal-cooled reactor, the supercritical carbon dioxide cycle power generation control system for a metal-cooled reactor comprising: Intermediate heat exchanger (1), reactor (3), turbine (5), regenerator (6), cooler (7), compressor (9), storage tank (11), generator (15) and control module; The hot-side outlet of the intermediate heat exchanger (1) is connected to the inlet of the reactor (3), and the hot-side inlet of the intermediate heat exchanger (1) is connected to the outlet of the reactor (3). The cold-side outlet of the intermediate heat exchanger (1) is connected to the inlet of the turbine (5); the outlet of the turbine (5) is connected to the hot-side inlet of the regenerator (6); the hot-side outlet of the regenerator (6) is connected to the hot-side inlet of the cooler (7), and the hot-side outlet of the cooler (7) is connected to the inlet of the compressor (9); the outlet of the compressor (9) is connected to the hot-side outlet of the regenerator (6) and the cold-side inlet of the regenerator (6) respectively; the cold-side outlet of the regenerator (6) is connected to the cold-side inlet of the intermediate heat exchanger (1); a storage tank (11) is provided between the outlet of the compressor (9) and the hot-side outlet connected to the regenerator (6). The turbine (5), generator (15) and compressor (9) are arranged coaxially in sequence; The control module includes: The core inlet temperature control module is used to control the outlet temperature of the reactor (3); Turbine inlet temperature control module, used to control the turbine (5) inlet temperature; Turbine inlet pressure control module, used to control turbine (5) inlet pressure; The compressor inlet temperature control module is used to control the compressor (9) inlet temperature; The compressor inlet pressure control module is used to control the compressor (9) inlet pressure; The reactor inlet temperature control module is used to control the reactor (3) inlet temperature; The speed control module is used to control the working fluid flow of the turbine (5) and the compressor (9); The flow control module is used to control the working fluid flow from the compressor (9) outlet to the storage tank (11) and from the storage tank (11) to the hot side inlet of the cooler (7); A circulating pump (2) is installed between the hot side outlet of the intermediate heat exchanger (1) and the inlet of the reactor (3). The turbine inlet temperature control module controls the turbine (5) inlet temperature by adjusting the speed of the circulating pump (2). The turbine (5) is equipped with a pressure reducing valve (4) at the inlet. The turbine inlet pressure control module controls the turbine (5) inlet pressure by adjusting the opening of the pressure reducing valve (4). The cooler (7) has a cold side outlet connected to a water tank (14); the water tank (14) is connected to the cold side inlet of the cooler (7); a water pump (13) is installed between the water tank (14) and the cold side inlet of the cooler (7). The compressor inlet temperature control module controls the compressor (9) inlet temperature by adjusting the speed of the water pump (13); The storage tank (11) is equipped with an inlet valve (10) at the inlet and an outlet valve (12) at the outlet. The compressor inlet pressure control module controls the compressor (9) inlet pressure by adjusting the opening and closing of the inlet valve (10) and the outlet valve (12). The flow control module controls the inlet flow of the turbine (5) and the inlet flow of the compressor (9) by adjusting the opening of the inlet valve (10) and the exhaust valve (12); Its characteristic is that it includes the following steps: In the medium-to-high load range, the load is adjusted using speed control, specifically as follows: Adjust the rotational speed of the turbine (5) to match the rotational speed with the maximum entropy efficiency of the turbine at the current flow rate; Reducing the rotation speed causes the working fluid flow rate to change linearly. By controlling the rotation speed of the circulating pump (2), the flow rate of the coolant in the reactor (3) is adjusted to keep the turbine (5) inlet temperature constant. Adjust the opening and closing states of the inlet valve (10) and outlet valve (12) of the storage tank (11) to keep the inlet pressure of the compressor (9) constant; The speed of the water pump (13) is controlled to adjust the cooling water flow rate to keep the inlet temperature of the compressor (9) constant. The inlet temperature of the reactor (3) is first slightly lowered and then slightly raised by adjusting the depth of the control rod of the reactor (3) inserted into the reactor core. In the low-load area, the turbine inlet pressure control method can be used to regulate the load, specifically as follows: Keep the turbine (5) at a low speed and reduce the turbine inlet pressure by reducing the opening of the pressure relief valve (4) in front of the turbine (5); The opening of the air inlet valve (10) and air outlet valve (12) of the regulating storage tank (11) controls the linear decrease of the working fluid flow rate in the system. Adjusting the rotational speed of the circulating pump (2) changes the coolant flow rate of the reactor (3) to keep the turbine (5) inlet temperature constant; Adjust the opening and closing states of the inlet valve (10) and the exhaust valve (12) of the storage tank (11) to keep the inlet pressure of the compressor (9) constant; Adjusting the speed of the water pump (13) changes the flow rate of cooling water to keep the inlet temperature of the compressor (9) constant. The inlet temperature of the reactor (3) is increased by adjusting the depth of the control rods inserted into the reactor core.

2. The method for controlling supercritical carbon dioxide cycle power generation in a metal-cooled reactor according to claim 1, characterized in that, A buffer tank (8) is provided between the hot side outlet of the cooler (7) and the inlet of the compressor (9).

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