Primary frequency modulation control system and method in reactor following control mode of sodium-cooled fast reactor

Abstract

The invention provides a primary frequency modulation control system and method in a sodium-cooled fast reactor following control mode. The primary frequency modulation control system in the sodium-cooled fast reactor following control mode comprises a first PID controller, a second PID controller, a steam turbine high-pressure regulating valve, a main water supply regulating valve, an evaporator, an F1 (X) function converter and an F2 (X) function converter. And the first PID controller is connected with a steam turbine high-pressure regulating valve. And the second PID controller is connected with the main feed water regulating valve and the evaporator. The PID controller and the function converter are correspondingly arranged for the high-pressure regulating valve and the main feed water regulating valve of the steam turbine respectively, so that the technical problem that the sodium-cooled fast reactor cannot participate in primary frequency modulation of the power grid in the prior art is solved.

Description

Technical Field

[0001] The present application belongs to the technical field of primary frequency regulation of steam turbine generator sets in nuclear power plants, and specifically relates to a primary frequency regulation control system and method in a sodium-cooled fast reactor follow-up control mode. Background Art

[0002] At present, the sodium-cooled fast reactor (also known as the sodium-cooled fast neutron nuclear reactor) adopts a machine-following-reactor control mode, that is, the power generation power of the steam turbine follows the power of the nuclear reactor, and the unit design does not consider the primary frequency regulation capability.

[0003] Under the new situation where the new power system is increasingly "high in proportion of power electronic equipment and high in proportion of renewable energy", the power grid has put forward higher requirements on the frequency regulation, peak regulation, excitation and voltage regulation capabilities of the generating units, and conducts assessments through market-oriented means. It requires the generating units to tap their potential in operation control, flexibly adjust the frequency while ensuring stable operation, and have stronger network-source coordination and support capabilities.

[0004] Therefore, how to enable sodium-cooled fast reactors to participate in the primary frequency regulation of the power grid, improve the reliability of the power grid, and increase the market competitiveness and economy of the units has become a technical problem that needs to be solved urgently. Summary of the invention

[0005] In view of this, the embodiments of the present application are committed to providing a primary frequency regulation control system and method under the sodium-cooled fast reactor machine-to-stack control mode, by respectively setting corresponding PID controllers and function converters for the turbine high-pressure regulating valve and the main feed water regulating valve, so as to solve the technical problem that the sodium-cooled fast reactor cannot participate in the primary frequency regulation of the power grid in the prior art.

[0006] The first aspect of the present application provides a primary frequency modulation control system under a sodium-cooled fast reactor follow-up control mode, and the primary frequency modulation control system under the sodium-cooled fast reactor follow-up control mode includes a first PID controller, a second PID controller, a turbine high-pressure regulating valve, a main feed water regulating valve, an evaporator, an F1(X) function converter, and an F2(X) function converter. The first PID controller is connected to the turbine high-pressure regulating valve, and is used to receive the main steam header pressure feedback value, calculate the turbine high-pressure regulating valve valve opening instruction using the main steam header pressure deviation value, and output the first valve position instruction current signal to the turbine high-pressure regulating valve according to the turbine high-pressure regulating valve valve opening instruction. The second PID controller is connected to the main feed water regulating valve and the evaporator, and is used to receive the evaporator outlet sodium temperature feedback value, calculate the main feed water regulating valve valve opening instruction using the evaporator outlet sodium temperature deviation value, and output the second valve position instruction current signal to the main feed water regulating valve according to the main feed water regulating valve valve opening instruction. The F1(X) function converter is used to receive the turbine speed deviation signal, and calculate the turbine high-pressure regulating valve opening correction value through the function F1(X) and then output it to the turbine high-pressure regulating valve. The F2(X) function converter is used to receive the turbine speed deviation signal, and calculate the main feedwater regulating valve opening correction value through the function F2(X) and then output it to the main feedwater regulating valve. The turbine high-pressure regulating valve is used to receive the first valve position command current signal and the turbine high-pressure regulating valve opening correction value when the primary frequency modulation is put into operation, and output the valve opening proportional to the first target value superimposed by the first valve position command current signal and the turbine high-pressure regulating valve opening correction value. The main feedwater regulating valve is used to receive the second valve position command current signal and the main feedwater regulating valve opening correction value when the primary frequency modulation is put into operation, and output the valve opening proportional to the second target value superimposed by the second valve position command current signal and the main feedwater regulating valve opening correction value.

[0007] In a specific embodiment of the present application, function F1(X) is a broken line, and the coordinate values ​​of the turning points of function F1(X) are (-3000, -3), (-7.6, -3), (-4, 0), (0, 0), (4, 0), (7.6, 3), and (3000, 3), respectively.

[0008] In a specific embodiment of the present application, function F2(X) is a broken line, and the coordinate values ​​of the turning points of function F2(X) are (-3000, -1821), (-7.6, -4.613), (-4, -2.428), (0, 0), (4, 2.428), (7.6, 4.613), and (3000, 1821), respectively.

[0009] In a specific implementation of the present application, the range of the first valve position command current signal is 4 mA-20 mA; and / or the range of the second valve position command current signal is 4 mA-20 mA.

[0010] In a specific embodiment of the present application, a first control program is installed in the first PID controller. The first control program uses formula 1 to calculate the change in the opening of the steam turbine high pressure regulating valve to generate a valve opening instruction of the steam turbine high pressure regulating valve.

[0011] dV=KP(F0-Ft)+KI(Ft-Ft1)+KD(Ft-2Ft1+Ft2)Formula 1.

[0012] In Formula 1, dV represents the change in the opening of the steam turbine high-pressure regulating valve, F0 represents the target value of the main steam header pressure, Ft represents the feedback value of the main steam header pressure, Ft1 represents the main steam header pressure value at time t1, Ft2 represents the main steam header pressure value at the previous moment of t1, KP represents the proportional coefficient, KI represents the integral coefficient, and KD represents the differential coefficient.

[0013] In a specific embodiment of the present application, KP is 0.01, KI is 1, and KD is 0.

[0014] In a specific implementation of the present application, a second control program is installed in the second PID controller, and the second control program calculates the change in the opening of the main water supply regulating valve to generate a valve opening instruction of the main water supply regulating valve.

[0015] dV'=KP'(F0'-Ft')+KI'(Ft'-Ft1')+KD'(Ft'-2Ft1'+Ft2') Formula 2.

[0016] In formula 2, dV' represents the change in the opening of the main feed water regulating valve, F0' represents the target value of the evaporator outlet sodium temperature, Ft' represents the evaporator outlet sodium temperature feedback value, Ft1' represents the evaporator outlet sodium temperature value at time t1, Ft2' represents the evaporator outlet sodium temperature value at the previous moment of t1, KP' represents the proportional coefficient, KI' represents the integral coefficient, and KD' represents the differential coefficient.

[0017] In a specific embodiment of the present application, KP' is 0.15, KI' is 1, and KD' is 0.

[0018] The second aspect of the present application provides a primary frequency modulation control method in a sodium-cooled fast reactor machine-following-stack control mode, and the primary frequency modulation control method in the sodium-cooled fast reactor machine-following-stack control mode includes: when the turbine speed deviates from 3000RPM and does not exceed ±4RPM, the primary frequency modulation is not actually put into operation, at this time, the main feed water regulating valve maintains the sodium temperature of the evaporator outlet through the second PID controller, and the turbine high-pressure regulating valve maintains the main steam header pressure through the first PID controller, at this time, the first circuit, the second circuit, and the third circuit reach a thermal power balance, and the amount of thermal power generated by the reactor is proportional to the amount of electrical power generated by the turbine. The unit is in the machine-following-stack mode, the turbine electrical power follows the reactor power, and the turbine high-pressure regulating valve does not control the electrical power; when the turbine speed deviates from 3000RPM and exceeds ±4RPM, the primary frequency modulation is actually put into operation, and at this time, the second of the main feed water regulating valve is used to control the main steam header pressure. The target value of the sodium temperature at the evaporator outlet of the PID controller follows the sodium temperature feedback value, that is, the PID input deviation is 0, and the PID output remains unchanged. At this time, the F2(X) function converter uses the function F2(X) to calculate the main feed water regulating valve opening correction value according to the turbine speed deviation signal. The main feed water regulating valve opening correction value is superimposed on the output of the second PID controller to control the valve opening of the main feed water regulating valve. The main steam manifold pressure target value of the first PID controller of the turbine high-pressure regulating valve follows the main steam manifold pressure feedback value, that is, the PID input deviation is 0, and the PID output remains unchanged. At this time, the F1(X) function converter uses the function F1(X) to calculate the turbine high-pressure regulating valve opening correction value according to the turbine speed deviation signal. The turbine high-pressure regulating valve opening correction value is superimposed on the first valve position command current signal to control the valve opening of the turbine high-pressure regulating valve.

[0019] In a specific embodiment of the present application, the primary frequency modulation control method in the sodium-cooled fast reactor follow-up control mode also includes: when the primary frequency modulation starts 60 seconds later, the primary frequency modulation is cut off and put into use, at this time, the unit exits the primary frequency modulation, the main feedwater regulating valve and the turbine high-pressure regulating valve return to PID control, the PID automatically tracks the current value, and slowly maintains the unit at a certain rate to achieve the re-matching of the reactor; during the start of the primary frequency modulation, if a preset fault condition occurs, the primary frequency modulation will be immediately exited. The preset fault conditions include the unit reactor shutdown, the operator manually cuts off the primary frequency modulation, the sodium temperature at the evaporator outlet deviates from the normal value and exceeds the operating range, the turbine exits the pressure control mode, the reactor quickly reduces power, the evaporator outlet superheat is too low, the turbine trips, the main steam header pressure deviates from the normal value and exceeds the allowable range, the frequency difference with the power grid is too large, the reactor power is less than 75%, and the main feedwater regulating valve is cut into manual mode.

[0020] The beneficial effect of the technical solution of the present application is that through the structural design and logical relationship design of the primary frequency regulation control system under the sodium-cooled fast reactor unit-to-reactor control mode, the sodium-cooled fast reactor is enabled to participate in the primary frequency regulation of the power grid, thereby increasing the reliability of the power grid, increasing the market competitiveness and economy of the unit, and contributing to the commercial promotion of fast reactors. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 The figure shows a block diagram of a primary frequency modulation control system in a sodium-cooled fast reactor follow-up control mode provided by an embodiment of the present application.

[0022] Figure 2 The figure is a flow chart of a steam turbine control method in a primary frequency modulation control method in a sodium-cooled fast reactor follow-up control mode provided in an embodiment of the present application.

[0023] Figure 3 The figure is a flow chart of a main feed water control method in a primary frequency modulation control method in a sodium-cooled fast reactor follow-up control mode provided in an embodiment of the present application. DETAILED DESCRIPTION

[0024] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0025] At least one embodiment of the present application provides a primary frequency modulation control system under a sodium-cooled fast reactor follow-up control mode, and the primary frequency modulation control system under the sodium-cooled fast reactor follow-up control mode includes a first PID controller, a second PID controller, a turbine high-pressure regulating valve, a main feed water regulating valve, an evaporator, an F1(X) function converter, and an F2(X) function converter. The first PID controller is connected to the turbine high-pressure regulating valve, and is used to receive the main steam header pressure feedback value, calculate the turbine high-pressure regulating valve valve opening instruction using the main steam header pressure deviation value, and output the first valve position instruction current signal to the turbine high-pressure regulating valve according to the turbine high-pressure regulating valve valve opening instruction. The second PID controller is connected to the main feed water regulating valve and the evaporator, and is used to receive the evaporator outlet sodium temperature feedback value, calculate the main feed water regulating valve valve opening instruction using the evaporator outlet sodium temperature deviation value, and output the second valve position instruction current signal to the main feed water regulating valve according to the main feed water regulating valve valve opening instruction. The F1(X) function converter is used to receive the turbine speed deviation signal, and calculate the turbine high-pressure regulating valve opening correction value through the function F1(X) and then output it to the turbine high-pressure regulating valve. The F2(X) function converter is used to receive the turbine speed deviation signal, and calculate the main feedwater regulating valve opening correction value through the function F2(X) and then output it to the main feedwater regulating valve. The turbine high-pressure regulating valve is used to receive the first valve position command current signal and the turbine high-pressure regulating valve opening correction value when the primary frequency modulation is put into operation, and output the valve opening proportional to the first target value superimposed by the first valve position command current signal and the turbine high-pressure regulating valve opening correction value. The main feedwater regulating valve is used to receive the second valve position command current signal and the main feedwater regulating valve opening correction value when the primary frequency modulation is put into operation, and output the valve opening proportional to the second target value superimposed by the second valve position command current signal and the main feedwater regulating valve opening correction value.

[0026] It should be noted that the shell side medium of the evaporator is the liquid metal sodium of the heat conductor of the second circuit, and the tube side medium is the main feed water of the third circuit. Sodium is cooled by water in the evaporator, and water is heated into steam by sodium. Since the heat conductor sodium of the second circuit is used to transfer the heat of the heat conductor sodium of the first circuit, and the sodium of the first circuit directly cools the nuclear reactor core, the temperature of the sodium of the second circuit directly affects whether the nuclear reactor can operate stably. The feed water flow in the evaporator can control the sodium temperature at the outlet of the evaporator. When the sodium temperature at the outlet of the evaporator is stable, the thermal power of the nuclear reactor is transferred to the third circuit through the sodium of the first and second circuits. At this time, the steam turbine realizes the reactor-machine matching by controlling the pressure of the main steam header.

[0027] The evaporator can be a direct-flow evaporator (also known as a direct-flow heat exchanger). The opening of the high-pressure regulating valve of the steam turbine can control the steam flow entering the steam turbine, thereby controlling the power generation of the steam turbine. The opening of the main feedwater regulating valve can control the feedwater flow entering the evaporator, thereby controlling the sodium temperature at the outlet of the evaporator. PID (Proportion Integration Differentiation) is also known as proportional, integral, and differential control.

[0028] Function F1(X) can be obtained by simulation calculation according to actual needs, and the embodiment of the present application does not specifically limit the function F1(X).

[0029] For example, in at least one embodiment of the present application, function F1(X) is a broken line, and the coordinate values ​​of the turning points of function F1(X) are (-3000, -3), (-7.6, -3), (-4, 0), (0, 0), (4, 0), (7.6, 3), and (3000, 3), respectively.

[0030] Specifically, please see Table 1 below.

[0031] Table 1 Coordinate values ​​of the turning point of function F1(X).

[0032] X -3000 -7.6 -4 0 4 7.6 3000 F1(X) -3 -3 0 0 0 3 3

[0033] Function F2(X) can be obtained by simulation calculation according to actual needs, and the embodiment of the present application does not specifically limit the function F2(X).

[0034] For example, in at least one embodiment of the present application, function F2(X) is a broken line, and the coordinate values ​​of the turning points of function F2(X) are (-3000, -1821), (-7.6, -4.613), (-4, -2.428), (0, 0), (4, 2.428), (7.6, 4.613), and (3000, 1821), respectively.

[0035] For details, please see Table 2 below.

[0036] Table 2 Coordinate values ​​of the turning point of function F2(X).

[0037] X -3000 -7.6 -4 0 4 7.6 3000 F2(X) -1821 -4.613 -2.428 0 2.428 4.613 1821

[0038] In at least one embodiment of the present application, the range of the first valve position command current signal is 4 mA-20 mA; and / or the range of the second valve position command current signal is 4 mA-20 mA.

[0039] In at least one embodiment of the present application, a first control program is installed in the first PID controller. The first control program uses formula 1 to calculate the change in the opening of the steam turbine high pressure regulating valve to generate a valve opening instruction for the steam turbine high pressure regulating valve.

[0040] dV=KP(F0-Ft)+KI(Ft-Ft1)+KD(Ft-2Ft1+Ft2)Formula 1.

[0041] In Formula 1, dV represents the change in the opening of the steam turbine high-pressure regulating valve, F0 represents the target value of the main steam header pressure, Ft represents the feedback value of the main steam header pressure, Ft1 represents the main steam header pressure value at time t1, Ft2 represents the main steam header pressure value at the previous moment of t1, KP represents the proportional coefficient, KI represents the integral coefficient, and KD represents the differential coefficient.

[0042] In at least one embodiment of the present application, KP is 0.01, KI is 1, and KD is 0.

[0043] In at least one embodiment of the present application, a second control program is installed in the second PID controller, and the second control program calculates the change in the opening of the main water supply regulating valve to generate a valve opening instruction of the main water supply regulating valve.

[0044] dV'=KP'(F0'-Ft')+KI'(Ft'-Ft1')+KD'(Ft'-2Ft1'+Ft2') Formula 2.

[0045] In formula 2, dV' represents the change in the opening of the main feed water regulating valve, F0' represents the target value of the evaporator outlet sodium temperature, Ft' represents the evaporator outlet sodium temperature feedback value, Ft1' represents the evaporator outlet sodium temperature value at time t1, Ft2' represents the evaporator outlet sodium temperature value at the previous moment of t1, KP' represents the proportional coefficient, KI' represents the integral coefficient, and KD' represents the differential coefficient.

[0046] In at least one embodiment of the present application, KP' is 0.15, KI' is 1, and KD' is 0.

[0047] At least one embodiment of the present application further provides a primary frequency modulation control method in a sodium-cooled fast reactor machine following the stack control mode, using the primary frequency modulation control system in a sodium-cooled fast reactor machine following the stack control mode provided by the embodiment of the present application. The primary frequency modulation control method in a sodium-cooled fast reactor machine following the stack control mode includes the following steps.

[0048] S1: When the turbine speed deviates from 3000RPM and does not exceed ±4RPM, the primary frequency regulation is not actually put into operation. At this time, the main feedwater regulating valve maintains the sodium temperature at the evaporator outlet through the second PID controller, and the turbine high-pressure regulating valve maintains the main steam header pressure through the first PID controller. At this time, the first, second, and third circuits reach thermal power balance. The steam turbine generates proportional electrical power to the thermal power generated by the reactor. The unit is in the machine-to-reactor mode, the turbine electrical power follows the reactor power, and the turbine high-pressure regulating valve does not control the electrical power.

[0049] S2: When the turbine speed deviates from 3000RPM and exceeds ±4RPM, the primary frequency modulation is actually put into operation. At this time, the target value of the evaporator outlet sodium temperature of the second PID controller of the main feedwater regulating valve follows the sodium temperature feedback value, that is, the PID input deviation is 0, and the PID output remains unchanged. At this time, the F2(X) function converter uses the function F2(X) to calculate the main feedwater regulating valve opening correction value according to the turbine speed deviation signal, and the main feedwater regulating valve opening correction value is superimposed on the output of the second PID controller to control the valve opening of the main feedwater regulating valve. The main steam header pressure target value of the first PID controller of the turbine high-pressure regulating valve follows the main steam header pressure feedback value, that is, the PID input deviation is 0, and the PID output remains unchanged. At this time, the F1(X) function converter uses the function F1(X) to calculate the turbine high-pressure regulating valve opening correction value according to the turbine speed deviation signal, and the turbine high-pressure regulating valve opening correction value is superimposed on the first valve position command current signal to control the valve opening of the turbine high-pressure regulating valve.

[0050] Specifically, the steam turbine control reference in primary frequency regulation Figure 2 , main feed water control reference Figure 3 .

[0051] It should be noted that, through the above step S2, the turbine valve position response and electric power response meet the primary frequency regulation requirements of the power grid. The main feedwater flow rate and turbine power are matched to keep the main steam header pressure relatively stable. Since the stack power does not change, the evaporator outlet sodium temperature will deviate from the current value. Since the mass and specific heat capacity of the sodium in the first and second circuits are very large, the evaporator outlet sodium temperature fluctuation value is within the allowable range of the unit.

[0052] Considering the matching of the reactor machine, the duration of a frequency modulation cannot exceed 60 seconds. In at least one embodiment of the present application, the primary frequency modulation control method in the sodium-cooled fast reactor machine and the reactor control mode further includes the following steps S3 and S4.

[0053] S3: When the primary frequency modulation starts, it will be cut off 60 seconds after it starts. At this time, the unit will exit the primary frequency modulation, and the main feed water regulating valve and the turbine high-pressure regulating valve will return to PID control. PID will automatically track the current value and slowly maintain the unit at a certain rate to achieve stack-machine re-matching.

[0054] S4: During the start of primary frequency regulation, if a preset fault condition occurs, primary frequency regulation will be immediately exited. The preset fault conditions include reactor shutdown, operator manually cutting off primary frequency regulation, evaporator outlet sodium temperature deviating from normal value beyond the operating range, turbine exiting pressure control mode, reactor rapid power reduction, evaporator outlet superheat too low, turbine tripping, main steam header pressure deviating from normal value beyond the allowable range, large frequency difference with the power grid, reactor power less than 75% and main feedwater regulating valve being cut into manual mode.

[0055] The beneficial effects of the embodiments of the present application are: enabling the sodium-cooled fast reactor to participate in the primary frequency regulation of the power grid, increasing the reliability of the power grid, increasing the market competitiveness and economy of the unit, and contributing to the commercial promotion of fast reactors.

[0056] It should be noted that the combination of the various technical features in the embodiments of the present application is not limited to the combination described in the embodiments of the present application or the combination described in the specific embodiments, and all technical features described in the present application can be freely combined or combined in any way unless there is a contradiction between them.

[0057] As shown in this application and claims, unless the context clearly indicates an exception, the words "a", "an" and / or "the" do not refer to the singular and may also include the plural. Generally speaking, the term "comprising" only indicates that the steps and elements that have been clearly identified are included, and these steps and elements do not constitute an exclusive list. The method or device may also include other steps or elements.

[0058] The terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features.

[0059] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A primary frequency modulation control system in a sodium-cooled fast reactor unit-to-pile control mode, characterized in that: It includes a first PID controller, a second PID controller, a turbine high-pressure regulating valve, a main feedwater regulating valve, an evaporator, an F1(X) function converter and an F2(X) function converter, Among them, the first PID controller is connected to the turbine high-pressure regulating valve, used to receive the main steam header pressure feedback value, use the main steam header pressure deviation value to calculate the turbine high-pressure regulating valve valve opening instruction, and output the first valve position instruction current signal to the turbine high-pressure regulating valve according to the turbine high-pressure regulating valve valve opening instruction; the second PID controller is connected to the main feed water regulating valve and the evaporator, used to receive the evaporator outlet sodium temperature feedback value, use the evaporator outlet sodium temperature deviation value to calculate the main feed water regulating valve valve opening instruction, and output the second valve position instruction current signal to the main feed water regulating valve according to the main feed water regulating valve valve opening instruction; the F1(X) function converter is used to receive the turbine speed deviation signal, and calculate the turbine high-pressure regulating valve through the function F1(X) The opening correction value is output to the turbine high-pressure regulating valve after being calculated; the F2(X) function converter is used to receive the turbine speed deviation signal, and calculate the main feed water regulating valve opening correction value through the function F2(X) and then output it to the main feed water regulating valve; the turbine high-pressure regulating valve is used to receive the first valve position command current signal and the turbine high-pressure regulating valve opening correction value when the primary frequency modulation is put into operation, and output a valve opening that is proportional to the first target value on which the first valve position command current signal and the turbine high-pressure regulating valve opening correction value are superimposed; the main feed water regulating valve is used to receive the second valve position command current signal and the main feed water regulating valve opening correction value when the primary frequency modulation is put into operation, and output a valve opening that is proportional to the second target value on which the second valve position command current signal and the main feed water regulating valve opening correction value are superimposed.

2. The primary frequency modulation control system in the sodium-cooled fast reactor unit-to-pile control mode according to claim 1, characterized in that: Function F1(X) is a broken line, and the coordinate values ​​of the turning points of function F1(X) are (-3000, -3), (-7.6, -3), (-4, 0), (0, 0), (4, 0), (7.6, 3), and (3000, 3), respectively.

3. The primary frequency modulation control system in the sodium-cooled fast reactor unit-to-pile control mode according to claim 1, characterized in that: Function F2(X) is a broken line, and the coordinate values ​​of the turning points of function F2(X) are (-3000, -1821), (-7.6, -4.613), (-4, -2.428), (0, 0), (4, 2.428), (7.6, 4.613), and (3000, 1821).

4. The primary frequency modulation control system in the sodium-cooled fast reactor unit-to-pile control mode according to claim 1, characterized in that: The range of the first valve position command current signal is 4 mA-20 mA; and / or the range of the second valve position command current signal is 4 mA-20 mA.

5. The primary frequency modulation control system in the sodium-cooled fast reactor unit-to-pile control mode according to claim 1, characterized in that: The first PID controller is installed with a first control program, which uses formula 1 to calculate the change in the opening of the high-pressure regulating valve of the steam turbine to generate a valve opening instruction of the high-pressure regulating valve of the steam turbine. dV=KP(F0-Ft)+KI(Ft-Ft1)+KD(Ft-2Ft1+Ft2) Formula 1 In Formula 1, dV represents the change in the opening of the steam turbine high-pressure regulating valve, F0 represents the target value of the main steam header pressure, Ft represents the feedback value of the main steam header pressure, Ft1 represents the main steam header pressure value at time t1, Ft2 represents the main steam header pressure value at the previous moment of t1, KP represents the proportional coefficient, KI represents the integral coefficient, and KD represents the differential coefficient.

6. The primary frequency modulation control system in the sodium-cooled fast reactor unit-to-pile control mode according to claim 5, characterized in that: KP is 0.01, KI is 1, and KD is 0.

7. The primary frequency modulation control system in the sodium-cooled fast reactor unit-to-pile control mode according to claim 1, characterized in that: The second PID controller is installed with a second control program, which calculates the change in the opening of the main water supply regulating valve to generate a valve opening instruction for the main water supply regulating valve. dV'=KP'(F0'-Ft')+KI'(Ft'-Ft1')+KD'(Ft'-2Ft1'+Ft2') Formula 2 In formula 2, dV' represents the change in the opening of the main feed water regulating valve, F0' represents the target value of the evaporator outlet sodium temperature, Ft' represents the evaporator outlet sodium temperature feedback value, Ft1' represents the evaporator outlet sodium temperature value at time t1, Ft2' represents the evaporator outlet sodium temperature value at the previous moment of t1, KP' represents the proportional coefficient, KI' represents the integral coefficient, and KD' represents the differential coefficient.

8. The primary frequency modulation control system in the sodium-cooled fast reactor unit-to-pile control mode according to claim 1, characterized in that: KP' is 0.15, KI' is 1, and KD' is 0.

9. A primary frequency modulation control method in a sodium-cooled fast reactor unit-to-pile control mode, characterized in that: include: When the turbine speed deviates from 3000RPM and does not exceed ±4RPM, the primary frequency regulation is not actually put into operation. At this time, the main feedwater regulating valve maintains the sodium temperature of the evaporator outlet through the second PID controller, and the turbine high-pressure regulating valve maintains the main steam header pressure through the first PID controller. At this time, the first, second and third circuits reach thermal power balance. The steam turbine generates electrical power in proportion to the thermal power generated by the reactor. The unit is in the machine-following-the-reactor mode, and the turbine electrical power follows the reactor power. The turbine high-pressure regulating valve does not control the electrical power. When the turbine speed deviates from 3000RPM and exceeds ±4RPM, the primary frequency modulation is actually put into operation. At this time, the evaporator outlet sodium temperature target value of the second PID controller of the main feed water regulating valve follows the sodium temperature feedback value, that is, the PID input deviation is 0, and the PID output remains unchanged. At this time, the F2(X) function converter uses the function F2(X) to calculate the main feed water regulating valve opening correction value according to the turbine speed deviation signal. The main feed water regulating valve opening correction value is superimposed on the output of the second PID controller to control the valve opening of the main feed water regulating valve. The main steam header pressure target value of the first PID controller of the turbine high pressure regulating valve follows the main steam header pressure feedback value, that is, the PID input deviation is 0, and the PID output remains unchanged. At this time, the F1(X) function converter uses the function F1(X) to calculate the turbine high pressure regulating valve opening correction value according to the turbine speed deviation signal. The turbine high pressure regulating valve opening correction value is superimposed on the first valve position command current signal to control the valve opening of the turbine high pressure regulating valve.

10. The primary frequency modulation control method in the sodium-cooled fast reactor machine-to-pile control mode according to claim 9, characterized in that: Also includes: 60 seconds after the start of the primary frequency modulation, the primary frequency modulation will be cut off. At this time, the unit will exit the primary frequency modulation, and the main feed water regulating valve and the turbine high pressure regulating valve will return to PID control. The PID will automatically track the current value and slowly maintain the unit at a certain rate to achieve the re-matching of the stack and the machine. During the start of the primary frequency regulation, if the preset fault conditions occur, the primary frequency regulation will be exited immediately. The preset fault conditions include shutdown of the unit reactor, manual cutting off of the primary frequency regulation by the operator, deviation of the sodium temperature at the evaporator outlet from the normal value exceeding the operating range, exit of the turbine from the pressure control mode, rapid power reduction of the reactor, too low superheat at the evaporator outlet, turbine tripping, main steam header pressure deviation from the normal value exceeding the allowable range, too large frequency difference with the power grid, reactor power less than 75% and the main feed water regulating valve being cut into manual mode.

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