A reactor full power range automatic control system and method
By employing automatic control methods with high and low power controllers and time delay elements in nuclear power plants, the problem of inaccurate pressure signals in the first stage of the steam turbine under low load was solved, achieving automatic control across the entire power range of the reactor and improving the degree of automation and economic efficiency.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2023-05-12
- Publication Date
- 2026-04-14
AI Technical Summary
Under low load, existing nuclear power plant reactors cannot achieve automatic control due to inaccurate pressure measurement signals from the first stage of the steam turbine. This forces the use of manual adjustment of control rods, limiting automatic control across the entire power range of the reactor.
The system employs high-power and low-power controllers for logic operations, combined with delay circuits and comparators. By using nuclear power measurements and average temperature signals, it achieves automatic control strategy switching between high and low loads, thereby expanding the range of automatic control.
It achieves automatic control across the entire power range of the reactor, improves the level of automation, reduces operator workload, lowers the possibility of human error, and has good economic benefits.
Smart Images
Figure CN116974246B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the technical field of nuclear power plant instrumentation and control systems, specifically relating to an automatic control system and method for the full power range of a reactor. Background Technology
[0002] Currently, the automatic control range of nuclear power plant reactor power control is generally between 15% FP (FP: full power) and 100% FP, with manual control used when the power is below 15% FP. To further improve the automatic control level of nuclear power plants, it is necessary to implement automatic control at low power levels, thereby achieving automatic control across the entire power range of the reactor. Among existing technologies, there are domestic nuclear power power control systems and methods. These systems receive key parameters from the turbine control system to achieve coordinated control between the reactor and the turbine. There are also nuclear power core target temperature control methods and systems, which define the relationship between temperature and turbine power and adjust the reactor power based on the average core temperature, thereby adjusting the core target temperature. Public reports also describe nuclear power plant unit power control systems that use rod control and position systems to generate rod lifting or insertion command signals based on operator instructions and system-generated switching signals to control reactor power.
[0003] However, none of the above-mentioned documents mention automatic control methods for the reactor across its full power range.
[0004] Currently, the reactor power control system in domestic nuclear power plants generally uses control rods to adjust the average temperature of the reactor coolant to match the reference temperature determined by the turbine load. The turbine load is characterized by the turbine's first-stage pressure signal. Because the first-stage pressure measurement signal is inaccurate under low load (reactor power less than 15% FP), existing nuclear power plants can only manually adjust the control rods under low load conditions. Summary of the Invention
[0005] The technical problem solved by this invention is to provide an automatic control system and method for the full power range of a reactor. Based on the actual situation that the first-stage pressure measurement signal of the steam turbine is inaccurate under low load, and automatic control cannot be achieved by adjusting the average temperature of the reactor coolant, the invention achieves automatic control under low load by adopting different control strategies, and switches between high and low load automatic control strategies at appropriate operating points, thereby realizing automatic control of the reactor across the full power range.
[0006] The technical solution adopted in this invention is as follows:
[0007] An automatic control system for a reactor across its full power range includes a controller signal selector, a high-power controller, a low-power controller, and a comparator. The high-power controller and the low-power controller are each connected to the controller signal selector. The comparator receives a high-power threshold N.S and nuclear power measurement value N C It also issues a power status signal S; the power status signal S is connected in parallel with a delay element, and the delay element issues a delayed status signal T. S The delayed state signal T S After being logically ANDed with the power status signal S, the control status signal C is transmitted to the controller signal selector. V .
[0008] The high-power controller and the low-power controller perform logic operations simultaneously and generate control rod action signals V respectively. H and V L .
[0009] The automatic control method for a reactor's full power range automatic control system includes the following steps:
[0010] S1. During the operation of a nuclear power plant, the high-power controller and low-power controller used for reactor power control perform calculations separately.
[0011] S2. Assume the high-power threshold Ns for nuclear power plants is 20%FP;
[0012] S3. Nuclear power plants are controlled to operate in the low-power range.
[0013] S4. The reactor continues to increase power, and the nuclear power plant operates in the high-power range.
[0014] In step S1, the high-power controller employs an average temperature control strategy with average temperature as the primary regulating variable, and outputs an action signal V. H The low-power controller employs a core power control strategy with core power as the primary regulating variable, and its output action signal is V. L .
[0015] The nuclear power plant operates under low-power range control, specifically including: the measured nuclear power value Nc and the set high-power threshold Ns are processed by a comparator to obtain a power state signal S=1; if the duration of the signal exceeds the set value of the delay circuit, the delay state signal T... S =1, S and T S The output signal after the AND operation is 1, which is the control status signal C. V =1; the control signal selector outputs a low-power controller control signal V. L The control rod's automatic action signal V = V L ;
[0016] If the duration of the signal is less than the set value of the delay circuit, the delay status signal T... S =0, S and T S The output signal after the AND operation is 0, which is the control status signal C.V =0; the control signal selector outputs a high-power controller control signal V. H The control rod's automatic action signal V = V H .
[0017] The reactor continues to increase power, and the nuclear power plant operates in the high-power range under control. Specifically, this includes: the measured nuclear power value Nc and the set high-power threshold Ns are processed by a comparator to obtain a power status signal S = 0. At this time, the output signal of the logic AND unit is false, i.e., the control status signal C. V =0; the control signal selector outputs a high-power controller control signal V. H The control rod's automatic action signal V = V H .
[0018] The 20%FP is the dividing line between high-power and low-power nuclear power plants.
[0019] Compared with the prior art, the beneficial effects of the present invention are as follows:
[0020] (1) The present invention provides an automatic control system and method for the full power range of a reactor. Based on the actual situation that the first stage pressure measurement signal of the steam turbine is inaccurate under low power and automatic control cannot be achieved by adjusting the average temperature of the reactor coolant, the present invention adopts a control strategy of directly controlling nuclear power under low power and a control strategy of controlling the average temperature of the reactor coolant under high power. The present invention also sets up control signal selection logic for high and low power, thereby realizing automatic control of the reactor within the full power range.
[0021] (2) The present invention provides an automatic control system and method for the full power range of a reactor, which can solve the problem that in the existing nuclear power plant reactor power control system, the control rods can only be manually adjusted due to the inaccurate pressure measurement signal of the first stage of the steam turbine under low power.
[0022] (3) The reactor full power range automatic control system and method provided by the present invention has an expanded automatic operation range, a high degree of automation, reduced operator workload, and reduced the possibility of human error, and has good economic benefits. Attached Figure Description
[0023] Figure 1 This is a schematic diagram of an automatic control system for the full power range of a reactor. Detailed Implementation
[0024] 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. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0025] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for 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. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.
[0026] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" 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 this invention based on the specific circumstances.
[0027] like Figure 1 As shown, the present invention provides an automatic control system for the full power range of a reactor, including a controller signal selector, a high-power controller, a low-power controller, and a comparator. The high-power controller and the low-power controller are respectively connected to the controller signal selector. During nuclear power plant operation, the high-power controller and the low-power controller simultaneously perform logic operations and generate control rod action signals V. H and V L The comparator receives a high power threshold N. S and nuclear power measurement value N C It also issues a power status signal S; the power status signal S is connected in parallel with a delay element, and the delay element issues a delayed status signal T. S The delayed state signal T S After being logically ANDed with the power status signal S, the control status signal C is transmitted to the controller signal selector. V ;
[0028] The high-power controller employs an average temperature control strategy with average temperature as the primary regulating variable, and outputs an action signal V. HThe low-power controller employs a core power control strategy with core power as the primary regulating variable, and its output action signal is V. L ;
[0029] The high power threshold N is set in the comparator. S and nuclear power measurement value N C Compare;
[0030] a. When (Ns-N C When ) < 0, it indicates that the nuclear power plant is operating at high power, and the power status signal S = 0. After passing through the "Logic AND" unit, the control status signal C V =0;
[0031] b.When (Ns-N C When the power status signal S > 0, it indicates that the nuclear power plant is operating at low power, and the power status signal S = 1; however, if the duration t is less than the set time of the delay circuit, the delay status signal T S =0, after "logical AND", the control status signal C V =0;
[0032] c. When (Ns-N) C When the power status signal S > 0, it indicates that the nuclear power plant is operating at low power, and the power status signal S = 1; if the duration t is greater than the set time of the delay circuit, the delay status signal T S =1, after "logical AND", the control status signal C V =1;
[0033] When C V When V = 0, the control signal selector selects the high-power controller output signal, and at this time the control rod automatic action signal V = V H When C V When V = 1, the control signal selector selects the low-power controller output signal, and at this time the control rod automatic action signal V = V L .
[0034] This invention employs an automatic average temperature control strategy with average temperature as the primary control variable at high power levels. At low power levels, considering the characteristics of nuclear power plant operation at low power, a control strategy is adopted that directly utilizes nuclear power measurement signals to control reactor nuclear power, thereby achieving automatic control of the reactor power control system at low power.
[0035] The automatic control strategy is switched between high and low power operating conditions by setting a nuclear power threshold signal Ns. When the nuclear power signal exceeds the threshold Ns, the reactor coolant average temperature control strategy is selected; when the nuclear power signal is below the high power threshold Ns and the duration exceeds the preset time interval T, the automatic control strategy is switched. CWhen switching from high power to low power, a control strategy under low load is selected. A delay is set to avoid unnecessary frequent switching. The high power threshold at the switching point from high power to low power should be set high enough to ensure the stability and repeatability of the turbine's first-stage pressure signal near that power value.
[0036] The present invention provides an automatic control method for a reactor across its full power range, comprising the following steps:
[0037] S1. During nuclear power plant operation, the high-power controller and low-power controller for reactor power control perform calculations separately. The high-power controller uses the reactor average temperature as the main control variable, and its output signal is V. H The low-power controller employs a control strategy that uses core power as the primary control variable, and its output signal is V. L .
[0038] S2. Let the high power threshold of the nuclear power plant be Ns = 20%FP, that is, 20%FP is the dividing value between high power and low power of the nuclear power plant.
[0039] S3. When the nuclear power plant is operating in the low-power range (nuclear power measurement value Nc ≤ 20% FP), the nuclear power measurement value Nc and the set high-power threshold Ns are processed by a comparator to obtain the power status signal S = 1. If the duration of the signal exceeds the set value of the delay circuit, the delay status signal T... S =1, S and T S The output signal after the AND operation is 1, which is the control status signal C. V =1. The control signal selector outputs a low-power controller control signal V. L The control rod's automatic action signal V = V L ;
[0040] If the duration of the signal is less than the set value of the delay circuit, the delay status signal T... S =0, S and T S The output signal after the AND operation is 0, which is the control status signal C. V =0; the control signal selector outputs a high-power controller control signal V. H The control rod's automatic action signal V = V H .
[0041] S4. When the reactor continues to increase power, and the nuclear power measurement value Nc > 20%FP, the nuclear power plant operates in the high-power range. The nuclear power measurement value Nc and the set high-power threshold Ns are processed by a comparator to obtain the power status signal S = 0. At this time, the logic AND unit output signal is false (logic signal 0), i.e., the control status signal C. V =0. The control signal selector outputs a high-power controller control signal V. HThe control rod's automatic action signal V = V H .
[0042] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.
[0043] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.
Claims
1. A reactor full-power range automatic control method, based on a reactor full-power range automatic control system, comprising a controller signal selector, a high-power controller, a low-power controller, and a comparator, wherein the high-power controller and the low-power controller are respectively connected to the controller signal selector; the comparator receives a high-power threshold N. S and nuclear power measurement value N C It also issues a power status signal S; the power status signal S is connected in parallel with a delay element, and the delay element issues a delayed status signal T. S The delayed state signal T S After being logically ANDed with the power status signal S, the control status signal C is transmitted to the controller signal selector. V The high-power controller and the low-power controller perform logic operations simultaneously, generating control rod action signals V respectively. H and V L ; Its features are, Includes the following steps: S1. During the operation of a nuclear power plant, the high-power controller and low-power controller used for reactor power control perform calculations separately. S2. Assume the high-power threshold for nuclear power plants is Ns = 20%FP; S3. Nuclear power plants are controlled to operate in the low-power range. S4. The reactor continues to increase power, and the nuclear power plant operates in the high-power range under control. In step S1, the high-power controller employs an average temperature control strategy with average temperature as the primary regulating variable, and outputs an action signal V. H The low-power controller employs a core power control strategy with core power as the primary regulating variable, and its output action signal is V. L ; The nuclear power plant operates under low-power range control, specifically including: the measured nuclear power value Nc and the set high-power threshold Ns are processed by a comparator to obtain a power state signal S=1; if the duration of the signal exceeds the set value of the delay circuit, the delay state signal T... S =1, S and T S The output signal after the AND operation is 1, which is the control status signal C. V =1; the controller signal selector outputs a low-power controller control signal V. L The control rod's automatic action signal V = V L ; If the duration of the signal is less than the set value of the delay circuit, the delay status signal T... S =0, S and T S The output signal after the AND operation is 0, which is the control status signal C. V =0; the controller signal selector outputs a high-power controller control signal V. H The control rod's automatic action signal V = V H .
2. The method according to claim 1, characterized in that, The reactor continues to increase power, and the nuclear power plant operates in the high-power range under control. Specifically, this includes: the measured nuclear power value Nc and the set high-power threshold Ns are processed by a comparator to obtain a power status signal S=0. At this time, the output signal of the logic AND unit is false, i.e., the control status signal C. V =0; the controller signal selector outputs a high-power controller control signal V. H The control rod's automatic action signal V = V H .
3. The method according to claim 2, characterized in that, The 20%FP is the dividing line between high-power and low-power nuclear power plants.