Device for simulating transient change of secondary side of steam generator and temperature control method

Abstract

The invention provides a device for simulating the transient change of the secondary side of a steam generator and a temperature control method, relates to the technical field of simulation of the transient change of the secondary side, and aims to simulate the transient change of the secondary side of the steam generator of a pressurized water reactor under the working conditions of load shedding, variable power and the like under accurate control. Comprising a steam generator simulation container, a pressure container, a pressure relief container, a plurality of electric heating elements, a plurality of valves and a water replenishing pressurization system. The steam generator simulation container is connected to the pressure container and the pressure relief container; the nitrogen injection connecting pipe of the pressure container is also connected with a nitrogen injection branch; the bottoms of the steam generator simulation container and the pressure container are respectively provided with an electric heating element, and the water replenishing pressurization system is connected to the pressure container and the steam generator simulation container. The system has the advantages of multi-path temperature change control, high temperature control precision and simple and accurate simulation control.

Description

Technical Field

[0001] The present invention relates to the technical field of simulation of secondary side transient changes, and in particular to a device and a temperature control method for simulating transient changes of a secondary side of a steam generator. Background Art

[0002] In a pressurized water reactor system, the steam generator is the hub connecting the primary and secondary circuits. It can transfer the heat generated by the reactor to the feed water on the secondary side of the steam generator, generate steam to drive the turbine to generate electricity. Whether the steam generator can operate safely and reliably has a very important impact on the normal operation of the entire pressurized water reactor device.

[0003] Pressurized water reactors usually need to perform load shedding conditions (causing the pressure and temperature of deionized water / steam on the secondary side of the steam generator to increase first and then decrease), power increase conditions (causing the pressure and temperature of deionized water / steam on the secondary side of the steam generator to decrease rapidly first and then maintain stability) and power reduction conditions (causing the pressure and temperature of deionized water / steam on the secondary side of the steam generator to increase rapidly first and then maintain stability) according to electricity demand, emergency situations or mission requirements. During load shedding conditions, power increase conditions and power reduction processes, the thermal-hydraulic parameters such as pressure, temperature, density and other measurement parameters related to safety, such as water level values, will change significantly on the secondary side of the steam generator, which places higher requirements on the material properties of components such as the heat transfer tubes of the steam generator, and the accuracy and reliability of measuring instruments.

[0004] Therefore, establishing a test device that can simulate the transient changes on the secondary side of the steam generator of a pressurized water reactor under load rejection and variable power conditions plays an important role in studying and improving the material properties, accuracy and reliability of measuring instruments related to the steam generator of the pressurized water reactor. Summary of the invention

[0005] The object of the present invention is to provide a device and a temperature control method for simulating transient changes on the secondary side of a steam generator, which can simulate transient changes on the secondary side of a steam generator of a pressurized water reactor under load rejection conditions and power variation conditions under accurate control.

[0006] The present invention is achieved through the following technical solutions:

[0007] The present invention first provides a device for simulating transient changes of the secondary side of a steam generator, comprising a steam generator simulation container, a pressure vessel, a pressure relief vessel, a plurality of electric heating elements, a plurality of valves and a water replenishment and pressurization system; the water vapor discharge pipe at the top of the steam generator simulation container is connected to the fluid injection pipe of the pressure relief vessel through a pipeline provided with a fifth valve; the water vapor injection pipe at the top of the steam generator simulation container is connected to the discharge pipe at the top of the pressure vessel through a pipeline provided with a fourth valve; the deionized water injection pipes at the bottom and top of the steam generator simulation container are respectively connected to the deionized water discharge pipe of the pressure vessel through a pipeline provided with a second valve and a third valve; the lower part of the steam generator simulation container is connected to the fluid injection pipe of the pressure relief vessel through a pipeline provided with a sixth valve; the nitrogen injection pipe of the pressure vessel is also connected to the nitrogen injection branch provided with a first valve;

[0008] The bottoms of the steam generator simulation container and the pressure container are respectively provided with a first electric heating element and a second electric heating element.

[0009] The water supplement and pressurization system is connected to the bottom of the pressure vessel and the bottom of the steam generator simulation vessel.

[0010] The present invention also provides a method for simulating transient changes of the secondary side of a steam generator, which is applied to the above-mentioned device for simulating transient changes of the secondary side of a steam generator, and comprises the following steps:

[0011] According to the target temperature of the transient change on the secondary side, the temperature of the steam generator simulation container is controlled by adjusting the first electric heating element, by adjusting the opening of the second, third, and fourth valves between the pressure vessel and the steam generator simulation container, and by adjusting the opening of the fifth valve between the steam generator simulation container and the pressure relief container.

[0012] Preferably, by adjusting the first electric heating element, by adjusting the second, third and fourth valve openings between the pressure vessel and the steam generator simulation vessel,

[0013] The method for controlling the temperature of the steam generator simulation container by adjusting the opening of the fifth valve between the steam generator simulation container and the pressure relief container is:

[0014] Get the target temperature T tar and the current temperature T pre ;

[0015] Get the adjusted temperature ΔT:

[0016] ΔT=T pre -T tar ;

[0017] If ΔT>0, by reducing the power of the first electric heating element, by increasing the opening of the fifth valve between the pressure relief vessel and the steam generator simulation vessel, by increasing the opening of the second and third valves between the pressure vessel and the steam generator simulation vessel, nitrogen is used to simultaneously pressurize the low-temperature deionized water and water vapor in the pressure vessel into the bottom and upper part of the steam generator simulation vessel to achieve rapid temperature reduction and precise control;

[0018] If ΔT<0, by increasing the power of the first electric heating element, by increasing the opening of the fourth valve between the pressure vessel and the steam generator simulation container, and by increasing the opening of the second, third, and fourth valves between the pressure vessel and the steam generator simulation container, the high-temperature deionized water and water vapor in the pressure vessel can be simultaneously injected into the steam generator simulation container to achieve rapid temperature reduction and precise control.

[0019] Preferably, when simulating load shedding conditions:

[0020] The water replenishment and exhaust of the steam generator simulation container and the pressure vessel are completed by the water replenishment and pressurization system;

[0021] The deionized water in the steam generator simulation container and the pressure container is heated by the first electric heating element and the second electric heating element respectively, and when the temperature of the deionized water is 150° C., the steam space is established respectively;

[0022] heating the steam generator simulation container by the first electric heating element until the temperature and pressure reach the operating range of the steam generator simulation container;

[0023] heating the pressure vessel by the second electric heating element until the temperature and pressure reach a level higher than that of the steam generator simulation vessel;

[0024] Raising the temperature of the steam generator simulation container by opening and adjusting the opening of the second valve, the opening of the third valve, the opening of the fourth valve and the first electric heating element;

[0025] Lowering the temperature of the steam generator simulation container by opening and adjusting the opening of the fifth valve, the opening of the sixth valve, and the first electric heating element;

[0026] When the required values ​​of the temperature and pressure reduction stage of the load shedding condition are reached, the fifth valve and the sixth valve are closed, and the power of the first electric heating element is adjusted to maintain the temperature and pressure of the deionized water and water vapor inside the steam generator simulation container.

[0027] Preferably, when simulating a power-up condition:

[0028] The water replenishment and exhaust of the steam generator simulation container and the pressure vessel are completed by the water replenishment and pressurization system;

[0029] heating the deionized water inside the steam generator simulation container by the first electric heating element;

[0030] Discharging a portion of the deionized water in the pressure vessel, and injecting nitrogen into the pressure vessel through the nitrogen injection branch to increase the pressure, so that the pressure inside the pressure vessel is greater than the pressure inside the steam generator simulation container;

[0031] According to the power increase working condition requirement, the deionized water inside the steam generator simulation container is heated by the first electric heating element;

[0032] Lowering the temperature of the steam generator simulation container by opening and adjusting the openings of the second valve, the third valve, and the fifth valve and cutting off the first electric heating element;

[0033] When the temperature requirement value of the power-up condition is reached, the second valve, the third valve and the fifth valve are closed, and the power of the first electric heating element is adjusted to maintain the temperature and pressure of the deionized water and water vapor inside the steam generator simulation container.

[0034] Preferably, when simulating a power reduction condition:

[0035] The water replenishment and exhaust of the steam generator simulation container and the pressure vessel are completed by the water replenishment and pressurization system;

[0036] The deionized water in the steam generator simulation container and the pressure container is heated by the first electric heating element and the second electric heating element respectively, and when the temperature of the deionized water is 150° C., the steam space is established respectively;

[0037] heating the steam generator simulation container by the first electric heating element until the temperature and pressure reach the operating range of the steam generator simulation container;

[0038] heating the pressure vessel by the second electric heating element until the temperature and pressure reach a level higher than that of the steam generator simulation vessel;

[0039] Raising the temperature of the steam generator simulation container by opening and adjusting the opening of the second valve, the opening of the third valve, the opening of the fourth valve and the first electric heating element;

[0040] When the required value of the power reduction condition is reached, the second valve, the third valve and the fourth valve are closed, and the power of the first electric heating element is adjusted to maintain the temperature and pressure of the deionized water and water vapor inside the steam generator simulation container.

[0041] Preferably, the method for increasing the temperature of the steam generator simulation container by adjusting the first electric heating element and adjusting the second, third and fourth valves between the pressure vessel and the steam generator simulation container is:

[0042] The fitting function f of the opening degree and opening time of each valve and the value of decreasing or increasing temperature under the corresponding simulation conditions is established respectively. ij (k i ,t),f ij (k i ,t) represents the opening of the i-th valve in the simulated situation j is k i The total temperature change when the duration is t;

[0043] Establishing a fitting function g(T0, p, t) of the initial temperature, the power and the opening time of the first electric heating element and the value of the temperature increase, where g(T0, p, t) represents the total value of the temperature change when the power of the first electric heating element is adjusted to p and the heating time is t when the initial temperature is T0;

[0044] Solve the following objective function to obtain the power of the first electric heating element and the opening of each valve:

[0045] Objective function:

[0046] Among them, e is a natural constant, var(k i ≠0) represents finding the variance of the opening of all valves whose opening is not 0;

[0047] Constraints:

[0048]

[0049] Among them, t th is the preset experience time threshold;

[0050] Substitute the obtained power of the first electric heating element and the opening of each valve into the following expression to solve the time t:

[0051]

[0052] The method for lowering the temperature of the steam generator simulation container by adjusting the second, third, and fourth valves between the pressure container and the steam generator simulation container and adjusting the fifth valve between the pressure relief container and the steam generator simulation container is as follows:

[0053] Solve the following objective function to obtain the opening of each valve:

[0054] Objective function: min t*var(k i ≠0);

[0055] Among them, e is a natural constant, var(k i ≠0) represents finding the variance of the opening of all valves whose opening is not 0;

[0056] Constraints:

[0057]

[0058] Substitute the obtained opening of each valve into the following expression to solve the time t:

[0059]

[0060] The technical solution of the present invention has at least the following advantages and beneficial effects:

[0061] The present invention not only realizes multi-method simulation of transient changes of the secondary side of the steam generator of a pressurized water reactor under load rejection conditions, but also realizes multi-path joint simulation of transient changes of the secondary side of the steam generator of a pressurized water reactor under power increase conditions and power reduction conditions by connecting steam generator simulation containers, pressure containers, pressure relief containers, electric heating elements, valves and other equipment.

[0062] The invention has a simple structure, high cost performance, and is easy to operate in various working condition simulations, and is convenient to be applied in actual work;

[0063] In the specific simulation, the device of the present invention is easy to calculate for temperature control, saves energy consumption as much as possible, has high reliability, and further improves the cost performance of the device application;

[0064] The present invention can be used for research and improvement of thermal hydraulic analysis, heat transfer tube material properties, accuracy and reliability of measuring instruments, etc. related to steam generators of onshore civilian pressurized water reactor nuclear power plants and offshore floating pressurized water reactor nuclear power plants, and can play an important role in improving the performance of pressurized water reactor steam generators and ensuring safe and reliable operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0065] Figure 1 A schematic diagram of the structure of a device for simulating transient changes on the secondary side of a steam generator provided in Example 1 of the present invention;

[0066] Icons: 101 - second electric heating element, 102 - first electric heating element, 103 - support reinforcement ring, 104 - support structure, V1 - first valve, V2 - second valve, V3 - third valve, V4 - fourth valve, V5 - fifth valve, V6 - sixth valve, V7 - seventh valve, V8 - eighth valve. DETAILED DESCRIPTION

[0067] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0068] Example 1

[0069] This embodiment provides a device for simulating transient changes in the secondary side of a steam generator, see Figure 1 The present invention first provides a device for simulating transient changes on the secondary side of a steam generator, comprising a steam generator simulation container, a pressure vessel, a pressure relief vessel, a plurality of electric heating elements, a plurality of valves and a water replenishment and pressurization system; the water vapor discharge pipe at the top of the steam generator simulation container is connected to the fluid injection pipe of the pressure relief vessel through a pipeline provided with a fifth valve V5; the water vapor injection pipe at the top of the steam generator simulation container is connected to the discharge pipe at the top of the pressure vessel through a pipeline provided with a fourth valve V4; the deionized water injection pipes at the bottom and top of the steam generator simulation container are respectively connected to the deionized water discharge pipe of the pressure vessel through a pipeline provided with a second valve V2 and a third valve V3; the lower part of the steam generator simulation container is connected to the fluid injection pipe of the pressure relief vessel through a pipeline provided with a sixth valve V6; the nitrogen injection pipe of the pressure vessel is also connected to a nitrogen injection branch provided with a first valve V1;

[0070] The bottoms of the steam generator simulation container and the pressure container are respectively provided with a first electric heating element 102 and a second electric heating element 101 .

[0071] The water supplement and pressurization system is connected to the bottom of the pressure vessel and the bottom of the steam generator simulation vessel.

[0072] In this embodiment, a plurality of support structures 104 are disposed in the middle of the steam generator simulation container, and a support reinforcement ring 103 is disposed at the bottom of the steam generator simulation container.

[0073] As a preferred solution, the material of the pipeline is stainless steel.

[0074] Furthermore, the water make-up and boosting system includes a water make-up pump, a boosting pump and a water make-up tank, one end of the water make-up pump and one end of the boosting pump are respectively connected to the bottom of the pressure vessel and the bottom of the steam generator simulation container through a pipeline provided with an eighth valve V8 and a seventh valve V7; the other end of the water make-up pump and the other end of the boosting pump are respectively connected to the water make-up tank through a pipeline.

[0075] The device of this embodiment can select one, two or three methods of injecting high-temperature and high-pressure water vapor, injecting high-temperature and high-pressure deionized water and adding electric heating elements to work together to increase temperature and pressure according to the requirements of different working conditions, and select one, two or three methods of discharging high-temperature and high-pressure water vapor, discharging high-temperature and high-pressure deionized water and removing electric heating elements to work together to reduce temperature and pressure. By controlling the opening of the valves on each branch and the input power of the electric heating elements, it is possible to achieve an accurate simulation of the transient changes on the secondary side of the steam generator of the pressurized water reactor under the load rejection condition. The injection and removal of high-temperature and high-pressure water vapor and high-temperature and high-pressure deionized water can be achieved by controlling the valves of the corresponding pipelines. This embodiment can simulate different working conditions, such as load rejection conditions, power increase conditions and power reduction conditions, through different temperature increase and temperature reduction control methods. In addition, the steam generator simulation container of this embodiment can achieve the tilting of the steam generator simulation container in any direction and at different angles by adjusting the height of the support seat of the fixed multiple support structures 104, thereby realizing the accurate simulation of the transient changes of the secondary side of the steam generator of the pressurized water reactor under the load rejection condition and the variable power condition when the steam generator is tilted. The support structure 104 can preferably be 4 and evenly distributed along the circumference of the steam generator simulation container. In addition, in addition to the low-temperature deionized water delivery equipment used in the water replenishment and pressurization system of this embodiment, there is no need to use additional high-temperature deionized water / water vapor delivery equipment, and the delivery of high-temperature and high-pressure deionized water, low-temperature and high-pressure deionized water, and high-temperature and high-pressure water vapor can be achieved. The pressure relief container can depressurize and cool the high-temperature and high-pressure water vapor and high-temperature and high-pressure deionized water.

[0076] Example 2

[0077] This embodiment is based on the technical solution of Embodiment 1 and provides a temperature control method for simulating transient changes on the secondary side of a steam generator, comprising the following steps:

[0078] According to the target temperature of the transient change on the secondary side, the temperature of the steam generator simulation container is controlled by adjusting the first electric heating element 102, by adjusting the opening of the second valve V2, the third valve V3, and the fourth valve V4 between the pressure vessel and the steam generator simulation container, and by adjusting the opening of the fifth valve V5 between the steam generator simulation container and the pressure relief container.

[0079] Further, by adjusting the first electric heating element 102, by adjusting the openings of the second valve V2, the third valve V3, and the fourth valve V4 between the pressure vessel and the steam generator simulation vessel, and by adjusting the opening of the fifth valve V5 between the steam generator simulation vessel and the pressure relief vessel, the method for controlling the temperature of the steam generator simulation vessel is:

[0080] Get the target temperature T tar and the current temperature T pre ;

[0081] Get the adjusted temperature ΔT:

[0082] ΔT=T pre -T tar ;

[0083] If ΔT>0, by reducing the power of the first electric heating element 102; by increasing the opening of the fifth valve V5 between the pressure relief vessel and the steam generator simulation vessel; by increasing the opening of the second valve V2 and the third valve V3 between the pressure vessel and the steam generator simulation vessel, nitrogen is used to press the low-temperature deionized water and water vapor in the pressure vessel into the bottom and upper part of the steam generator simulation vessel at the same time; these three methods can work together to achieve rapid temperature reduction and precise control;

[0084] If ΔT<0, by increasing the power of the first electric heating element 102; by increasing the opening of the fourth valve V4 between the pressure vessel and the steam generator simulation container; by increasing the opening of the second valve V2, the third valve V3, and the fourth valve V4 between the pressure vessel and the steam generator simulation container, the high-temperature deionized water and water vapor in the pressure vessel can be injected into the steam generator simulation container at the same time; these three methods can work together to achieve rapid temperature reduction and precise control.

[0085] This embodiment can simulate a variety of working conditions, as follows:

[0086] First, when simulating load shedding conditions:

[0087] The water replenishment and exhaust of the steam generator simulation container and the pressure vessel are completed by the water replenishment and pressurization system;

[0088] The deionized water in the steam generator simulation container and the pressure container is heated by the first electric heating element 102 and the second electric heating element 101 respectively, and when the temperature of the deionized water is 150° C., the steam space is established respectively;

[0089] Heating the steam generator simulation container by the first electric heating element 102 until the temperature and pressure reach the operating range of the steam generator simulation container;

[0090] The pressure vessel is heated by the second electric heating element 101 until the temperature and pressure reach a level higher than that of the steam generator simulation vessel;

[0091] Raising the temperature of the steam generator simulation container by opening and adjusting the opening of the second valve V2, the opening of the third valve V3, the opening of the fourth valve V4 and the first electric heating element 102;

[0092] Lowering the temperature of the steam generator simulation container by opening and adjusting the opening of the fifth valve V5, the sixth valve V6 and adjusting the opening of the first electric heating element 102;

[0093] When the required values ​​of the temperature and pressure reduction stage of the load shedding condition are reached, the fifth valve V5 and the sixth valve V6 are closed, and the power of the first electric heating element 102 is adjusted to maintain the temperature and pressure of the deionized water and water vapor inside the steam generator simulation container.

[0094] Secondly, when simulating the power-up condition:

[0095] The water replenishment and exhaust of the steam generator simulation container and the pressure vessel are completed by the water replenishment and pressurization system;

[0096] Heating the deionized water inside the steam generator simulation container by the first electric heating element 102;

[0097] Discharging a portion of the deionized water in the pressure vessel, and injecting nitrogen into the pressure vessel through the nitrogen injection branch to increase the pressure, so that the pressure inside the pressure vessel is greater than the pressure inside the steam generator simulation container;

[0098] According to the power increase working condition requirement, the deionized water inside the steam generator simulation container is heated by the first electric heating element 102;

[0099] Lowering the temperature of the steam generator simulation container by opening and adjusting the openings of the second valve V2, the third valve V3 and the fifth valve V5 and cutting off the first electric heating element 102;

[0100] When the temperature requirement of the power-up condition is reached, the second valve V2, the third valve V3 and the fifth valve V5 are closed, and the power of the first electric heating element 102 is adjusted to maintain the temperature and pressure of the deionized water and water vapor inside the steam generator simulation container.

[0101] On the other hand, when simulating derated conditions:

[0102] The water replenishment and exhaust of the steam generator simulation container and the pressure vessel are completed by the water replenishment and pressurization system;

[0103] The deionized water in the steam generator simulation container and the pressure container is heated by the first electric heating element 102 and the second electric heating element 101 respectively, and when the temperature of the deionized water is 150° C., the steam space is established respectively;

[0104] Heating the steam generator simulation container by the first electric heating element 102 until the temperature and pressure reach the operating range of the steam generator simulation container;

[0105] The pressure vessel is heated by the second electric heating element 101 until the temperature and pressure reach a level higher than that of the steam generator simulation vessel;

[0106] Raising the temperature of the steam generator simulation container by opening and adjusting the opening of the second valve V2, the opening of the third valve V3, the opening of the fourth valve V4 and the first electric heating element 102;

[0107] When the required value of the power reduction condition is reached, the second valve V2, the third valve V3 and the fourth valve V4 are closed, and the power of the first electric heating element 102 is adjusted to maintain the temperature and pressure of the deionized water and water vapor inside the steam generator simulation container.

[0108] Finally, the method of increasing the temperature of the steam generator simulation container by adjusting the first electric heating element and adjusting the second valve V2, the third valve V3, and the fourth valve V4 between the pressure vessel and the steam generator simulation container is preferably:

[0109] The fitting function f of the opening degree and opening time of each valve and the value of decreasing or increasing temperature under the corresponding simulation conditions is established respectively. ij (k i ,y),f ij (k i ,t) represents the opening of the ith valve in the simulated case j is k i The total value of temperature change when the duration is t;

[0110] Establishing a fitting function g(T0, p, t) of the initial temperature, the power and the opening time of the first electric heating element and the value of the temperature increase, where g(T0, p, t) represents the total value of the temperature change when the power of the first electric heating element is adjusted to p and the heating time is t when the initial temperature is T0;

[0111] Solve the following objective function to obtain the power of the first electric heating element and the opening of each valve:

[0112] Objective function:

[0113] Among them, e is a natural constant, var(k i ≠0) represents finding the variance of the opening of all valves whose opening is not 0;

[0114] Constraints:

[0115]

[0116] Among them, t th is the preset experience time threshold;

[0117] Substitute the obtained power of the first electric heating element and the opening of each valve into the following expression to solve the time t:

[0118]

[0119] The method for lowering the temperature of the steam generator simulation container by adjusting the second valve V2, the third valve V3, the fourth valve V4 between the pressure container and the steam generator simulation container, and adjusting the fifth valve V5 between the pressure relief container and the steam generator simulation container is as follows:

[0120] Solve the following objective function to obtain the opening of each valve:

[0121] Objective function: min t*var(k i ≠0);

[0122] Among them, e is a natural constant, var(k i ≠0) represents finding the variance of the opening of all valves whose opening is not 0;

[0123] Constraints:

[0124]

[0125] Substitute the obtained opening of each valve into the following expression to solve the time t:

[0126]

[0127] In this embodiment, when setting a specific temperature adjustment scheme, the power consumption of the first heating element and the difference in the opening and closing degrees of different valves are reduced as much as possible, which can facilitate adjustment and reduce power consumption and save energy. The purpose of setting constraints is to avoid too long an adjustment time, so that the adjustment can definitely achieve the purpose within a certain empirical time.

[0128] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A device for simulating transient changes on the secondary side of a steam generator, characterized in that: It comprises a steam generator simulation container, a pressure container, a pressure relief container, a plurality of electric heating elements, a plurality of valves and a water replenishment and pressurization system; the water vapor discharge pipe on the top of the steam generator simulation container is connected to the fluid injection pipe of the pressure relief container through a pipeline provided with a fifth valve; the water vapor injection pipe on the top of the steam generator simulation container is connected to the discharge pipe on the top of the pressure container through a pipeline provided with a fourth valve; the deionized water injection pipes at the bottom and top of the steam generator simulation container are respectively connected to the deionized water discharge pipe of the pressure container through a pipeline provided with a second valve and a third valve; the lower part of the steam generator simulation container is connected to the fluid injection pipe of the pressure relief container through a pipeline provided with a sixth valve; the nitrogen injection pipe of the pressure container is also connected to the nitrogen injection branch provided with a first valve; The bottoms of the steam generator simulation container and the pressure container are respectively provided with a first electric heating element and a second electric heating element. The water supplement and pressurization system is connected to the bottom of the pressure vessel and the bottom of the steam generator simulation vessel.

2. A method for simulating transient changes in the secondary side of a steam generator, applied to the device for simulating transient changes in the secondary side of a steam generator as claimed in claim 1, characterized in that: The following steps are involved: According to the target temperature of the transient change on the secondary side, the temperature of the steam generator simulation container is controlled by adjusting the first electric heating element, by adjusting the opening of the second, third, and fourth valves between the pressure vessel and the steam generator simulation container, and by adjusting the opening of the fifth valve between the steam generator simulation container and the pressure relief container.

3. The temperature control method for simulating transient changes of the secondary side of a steam generator according to claim 2, characterized in that: By adjusting the first electric heating element, by adjusting the second, third, and fourth valve openings between the pressure vessel and the steam generator simulation vessel, The method for controlling the temperature of the steam generator simulation container by adjusting the opening of the fifth valve between the steam generator simulation container and the pressure relief container is: Get the target temperature T tar and the current temperature T pre ; Get the adjusted temperature ΔT: ΔT=T pre -T tar ; If ΔT>0, by reducing the power of the first electric heating element, by increasing the opening of the fifth valve between the pressure relief vessel and the steam generator simulation vessel, by increasing the opening of the second and third valves between the pressure vessel and the steam generator simulation vessel, nitrogen is used to simultaneously pressurize the low-temperature deionized water and water vapor in the pressure vessel into the bottom and upper part of the steam generator simulation vessel to achieve rapid temperature reduction and precise control; If ΔT<0, by increasing the power of the first electric heating element, by increasing the opening of the fourth valve between the pressure vessel and the steam generator simulation container, and by increasing the opening of the second, third, and fourth valves between the pressure vessel and the steam generator simulation container, the high-temperature deionized water and water vapor in the pressure vessel can be simultaneously injected into the steam generator simulation container to achieve rapid temperature reduction and precise control.

4. The temperature control method for simulating transient changes of the secondary side of a steam generator according to claim 3, characterized in that: When simulating load shedding conditions: The water replenishment and exhaust of the steam generator simulation container and the pressure vessel are completed by the water replenishment and pressurization system; The deionized water in the steam generator simulation container and the pressure container is heated by the first electric heating element and the second electric heating element respectively, and when the temperature of the deionized water is 150° C., the steam space is established respectively; heating the steam generator simulation container by the first electric heating element until the temperature and pressure reach the operating range of the steam generator simulation container; heating the pressure vessel by the second electric heating element until the temperature and pressure reach a level higher than that of the steam generator simulation vessel; Raising the temperature of the steam generator simulation container by opening and adjusting the opening of the second valve, the opening of the third valve, the opening of the fourth valve and the first electric heating element; Lowering the temperature of the steam generator simulation container by opening and adjusting the opening of the fifth valve, the opening of the sixth valve, and the first electric heating element; When the required values ​​of the temperature reduction and pressure reduction stage of the load shedding condition are reached, the fifth valve and the sixth valve are closed, and the power of the first electric heating element is adjusted to maintain the temperature and pressure of the deionized water and water vapor inside the steam generator simulation container.

5. The temperature control method for simulating transient changes in the secondary side of a steam generator according to claim 3, characterized in that: When simulating power-up conditions: The water replenishment and exhaust of the steam generator simulation container and the pressure vessel are completed by the water replenishment and pressurization system; heating the deionized water inside the steam generator simulation container by the first electric heating element; Discharging a portion of the deionized water in the pressure vessel, and injecting nitrogen into the pressure vessel through the nitrogen injection branch to increase the pressure, so that the pressure inside the pressure vessel is greater than the pressure inside the steam generator simulation container; According to the power increase working condition requirement, the deionized water inside the steam generator simulation container is heated by the first electric heating element; Lowering the temperature of the steam generator simulation container by opening and adjusting the openings of the second valve, the third valve, and the fifth valve and cutting off the first electric heating element; When the temperature requirement value of the power-up condition is reached, the second valve, the third valve and the fifth valve are closed, and the power of the first electric heating element is adjusted to maintain the temperature and pressure of the deionized water and water vapor inside the steam generator simulation container.

6. The temperature control method for simulating transient changes of the secondary side of a steam generator according to claim 3, characterized in that: When simulating a reduced power condition: The water replenishment and exhaust of the steam generator simulation container and the pressure vessel are completed by the water replenishment and pressurization system; The deionized water in the steam generator simulation container and the pressure container is heated by the first electric heating element and the second electric heating element respectively, and when the temperature of the deionized water is 150° C., the steam space is established respectively; heating the steam generator simulation container by the first electric heating element until the temperature and pressure reach the operating range of the steam generator simulation container; heating the pressure vessel by the second electric heating element until the temperature and pressure reach a level higher than that of the steam generator simulation vessel; Raising the temperature of the steam generator simulation container by opening and adjusting the opening of the second valve, the opening of the third valve, the opening of the fourth valve and the first electric heating element; When the required value of the power reduction condition is reached, the second valve, the third valve and the fourth valve are closed, and the power of the first electric heating element is adjusted to maintain the temperature and pressure of the deionized water and water vapor inside the steam generator simulation container.

7. The temperature control method for simulating transient changes in the secondary side of a steam generator according to claim 3, characterized in that: The method for increasing the temperature of the steam generator simulation container by adjusting the first electric heating element and adjusting the second, third and fourth valves between the pressure vessel and the steam generator simulation container is: The fitting function f of the opening degree and opening time of each valve and the value of decreasing or increasing temperature under the corresponding simulation conditions is established respectively. ij (k i ,t),f ij (k i ,t) represents the opening of the i-th valve in the simulated situation j is k i The total temperature change when the duration is t; Establishing a fitting function g(T0, p, t) of the initial temperature, the power and the opening time of the first electric heating element and the value of the temperature increase, where g(T0, p, t) represents the total value of the temperature change when the power of the first electric heating element is adjusted to p and the heating time is t when the initial temperature is T0; Solve the following objective function to obtain the power of the first electric heating element and the opening of each valve: Objective function: Among them, e is a natural constant, var(k i ≠0) represents finding the variance of the opening of all valves whose opening is not 0; Constraints: Among them, t th is the preset experience time threshold; Substitute the obtained power of the first electric heating element and the opening of each valve into the following expression to solve the time t: The method for lowering the temperature of the steam generator simulation container by adjusting the second, third, and fourth valves between the pressure container and the steam generator simulation container and adjusting the fifth valve between the pressure relief container and the steam generator simulation container is as follows: Solve the following objective function to obtain the opening of each valve: Objective function: min t*var(k i ≠0); Among them, e is a natural constant, var(k i ≠0) represents finding the variance of the opening of all valves whose opening is not 0; Constraints: Substitute the obtained opening of each valve into the following expression to solve the time t:

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