Method for calculating reactivity coefficient ratio of nuclear power plant and calculating device thereof
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- CNNC FUJIAN FUQING NUCLEAR POWER
- Filing Date
- 2023-08-14
- Publication Date
- 2026-06-09
Smart Images
Figure CN117171483B_ABST
Abstract
Description
Technical Field
[0001] This application belongs to the field of nuclear power technology, specifically relating to a method and apparatus for calculating the reactivity ratio of a nuclear power plant. Background Technology
[0002] The reactivity ratio is defined as the ratio of the total temperature coefficient to the Doppler power coefficient. In typical nuclear power plants, reactivity ratio measurements are performed to obtain this ratio. To distinguish it from the physical concept of "reactivity coefficient," this ratio will be referred to as the "reactivity ratio" below. Nuclear power plants typically perform reactivity ratio measurements during commissioning to verify that the reactor core meets design requirements.
[0003] However, the current calculation results of the reactivity ratio have a large error compared with the design value. The main reason is that there are defects in the principle and method, which leads to a large error in the measurement results of the reactivity ratio and reduces the accuracy of the verification results of the core meeting the design requirements. Summary of the Invention
[0004] In view of this, the embodiments of this application aim to provide a method and apparatus for calculating the reactivity ratio of a nuclear power plant. By using a rigorously derived formula for calculating the reactivity ratio, the reactivity ratio of the nuclear power plant is calculated, thereby improving the accuracy of the calculation results and more accurately verifying whether the reactor core meets the design requirements.
[0005] The first aspect of this application provides a method for calculating the reactivity ratio of a nuclear power plant, the method comprising: obtaining the reactor thermal power Pr(t) at the current time t, the reactor thermal power Pr0 at the initial time, and the average reactor coolant temperature T at the current time t. avg (t), the average reactor coolant temperature at the initial moment T0, and the rate of change of the average reactor coolant temperature at t=∞. The time t1 for the reactor thermal power to change from Pr0 to Pr(∞) is used to obtain the Doppler power coefficient α. dpc Doppler temperature coefficient α dtc Full power reference temperature T hfp and the reference temperature T for zero power hzp According to Pr(t), Pr0, T avg (t), T0, D ∞ , t, t1, α dtc α dpc T hfp and T hzp The final reactivity coefficient of the nuclear power plant at the current time t was calculated to be...
[0006]
[0007] In the above scheme, the final reactivity ratio of the nuclear power plant at the current time t is calculated according to a formula for calculating the reactivity ratio derived through rigorous steps and mathematical methods. This results in a smaller error and higher accuracy in the final reactivity ratio, which in turn helps to more accurately verify whether the reactor core meets the design requirements.
[0008] In one specific embodiment of this application, the above is based on Pr(t), Pr0, T avg (t), T0, D ∞ , t, t1, α dtc α dpc T hfp and T hzp The final reactivity coefficient of the nuclear power plant at the current time t was calculated to be... Including: based on Pr(t), Pr0, T avg (t), T0, D ∞ The initial reactivity coefficient of the nuclear power plant at the current time t is calculated using t, t1, and t2. According to T hzp T hfp α dtc and α dpc The correction parameter Z is calculated; based on the initial reactivity coefficient ratio of the nuclear power plant at the current time t... And the correction parameter Z, are calculated to obtain
[0009] A second aspect of this application provides a calculation apparatus for the reactivity ratio of a nuclear power plant, comprising an acquisition module and a calculation module. The acquisition module is used to acquire the reactor thermal power Pr(t) at the current time t, the reactor thermal power Pr0 at the initial time, and the average reactor coolant temperature T at the current time t. avg (t), the average reactor coolant temperature at the initial moment T0, and the rate of change of the average reactor coolant temperature at t=∞. The time t1 for the reactor thermal power to change from Pr0 to Pr(∞) was determined, and the Doppler power coefficient α was obtained. dpc Doppler temperature coefficient α dtc Full power reference temperature T hfp and the reference temperature T for zero power hzp The calculation module is used to calculate Pr(t), Pr0, and T. avg (t), T0, D ∞ , t, t1, α dtc α dpc T hfp and T hzp The final reactivity coefficient of the nuclear power plant at the current time t was calculated to be...
[0010]
[0011] A third aspect of this application provides a computer-readable storage medium storing executable instructions for a computer. When executed by a processor, the executable instructions implement the method for calculating the reactivity ratio of a nuclear power plant according to the first aspect of this application.
[0012] A fourth aspect of this application provides an electronic device comprising a processor and a memory. The processor is used to execute the method for calculating the reactivity ratio of a nuclear power plant according to the first aspect of this application. The memory is used to store executable instructions of the processor. Attached Figure Description
[0013] Figure 1 The diagram shown is a flowchart illustrating a method for calculating the reactivity ratio of a nuclear power plant according to an embodiment of this application.
[0014] Figure 2 The diagram shown is a flowchart illustrating a method for calculating the reactivity ratio of a nuclear power plant according to another embodiment of this application.
[0015] Figure 3 The diagram shown is a structural schematic of a nuclear power plant reactivity ratio calculation device provided in an embodiment of this application.
[0016] Figure 4 The diagram shown is a block diagram of an electronic device provided in one embodiment of this application. Detailed Implementation
[0017] Under steady-state full-power conditions, the reactor thermal power decreases to 5%FP, with a power reduction rate of approximately 5%FP / min. The control rod assembly is placed in "manual" mode and remains inactive for 30 minutes after the load reduction, and boron adjustment is prohibited. Temperature and xenon concentration will change after the power reduction.
[0018] The decrease in reactivity caused by an increase in xenon concentration is comparable to the increase in reactivity caused by a decrease in the average temperature of the reactor coolant. The negative reactivity introduced by the xenon transient can be determined by analyzing the rate of temperature decrease in the moderator, and the overall temperature coefficient α can be estimated. ttc With Doppler power coefficient α dpc The ratio of the reactivity coefficients is also known as the reactivity coefficient ratio.
[0019] The reference author is Pan Zefei, and the book is titled "Experimental Methods for Reactor Physics in Pressurized Water Reactor Nuclear Power Plants". The traditional expression for the reactive equilibrium equation is as follows: Formula (1).
[0020] ρ(t)=α dpc ×(Pr(t)-Pr0)+α ttc×(T avg (t)-T0)+Δρ xe (t) (1)
[0021] In formula (1), t: the current time t after the load change, in minutes. Pr(t): the reactor thermal power at the current time t, in %FP. Pr0: the reactor thermal power at the initial time, in %FP; T avg (t): Average reactor coolant temperature at current time t, in °C. T0: Average reactor coolant temperature at initial time, in °C; Δρ xe (t): Represents the change in reactivity due to a change in xenon concentration, in pcm; α dpc Doppler power coefficient: Responsive change due to the Doppler effect when power changes by 1% of rated power. α ttc Total temperature coefficient, representing the change in reactivity caused by temperature variations in fuel and moderator, is expressed in pcm / ℃.
[0022] Traditional equation derivation makes a lot of assumptions and omissions, and finally the formula for calculating the reactivity coefficient ratio is as follows (2).
[0023]
[0024] In formula (2), ΔP(t) represents the difference between the core power at the current time t and the initial power, in units of %FP, ΔP(t) = Pr(t) - Pr0; ΔT avg (t): Represents the difference between the average reactor coolant temperature at the current time t and the average temperature at the initial time, in °C, ΔT avg (t)=T avg (t)-T0; t1: the time it takes for the reactor thermal power to change from Pr0 to Pr(∞), in minutes; The unit is ℃ / minute.
[0025] Careful study revealed that, due to the numerous assumptions and omissions made in the traditional equations during the derivation of formula (2), the calculated reactivity coefficient was less accurate than... The error compared to the design value is relatively large.
[0026] To address the aforementioned problems, this application provides a method and apparatus for calculating the reactivity ratio of a nuclear power plant. The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.
[0027] Based on a rigorous reactivity equilibrium equation, this application derives a formula for calculating the reactivity coefficient ratio through rigorous derivation, as detailed below.
[0028] Δρ=Δρ xe (t)+Δρ(Pr) dop +Δρ(T ref ) mot +Δρ ΔT
[0029] ρ(t)-ρ(0)=Δρ xe (t)+[ρ(t,Pr(t)) dop -ρ(0,Pr0) dop ]+[ρ(t,T ref (t)) mot -ρ(0,T ref (0)) mot ]+[ρ(t) ΔT -ρ(0) ΔT ]
[0030] =Δρ xe (t)+α dpc ×(Pr(t)-Pr0)+α mtc ×(T ref (t)-T ref (0))+[(T avg (t)-T ref (t))-(T avg (0)-T ref (0))]×(α dtc +α mtc )
[0031] =Δρ xe (t)+α dpc ×(Pr(t)-Pr0)+α mtc ×(T ref (t)-T ref (0))+[(T avg (t)-T ref (t))-(T avg (0)-Tref (0))]×α mtc +[(T avg (t)-T ref (t))-(T avg (0)-T ref (0))]×α dtc
[0032] =Δρ xe (t)+α dpc ×(Pr(t)-Pr0)+α mtc ×(T avg (t)-T avg (0))+α dtc (T avg (t)-T avg (0))-α dtc (T ref (t)-T ref (0))
[0033] =Δρ xe (t)+α dpc ×(Pr(t)-Pr0)+α ttc ×(T avg (t)-T avg (0))-α dtc ×(T ref (t)-T ref (0))(3)
[0034] In formula (3), α mtc : Temperature coefficient of the moderator, in pcm / ℃; α dtc : Doppler temperature coefficient, in pcm / ℃. t: Current time t after the load change, in minutes; Pr(t): Reactor thermal power at current time t, in %FP. The reactor core remains critical in the initial state of the experiment, i.e., ρ(0) = 0.
[0035] Comparing formula (3) and formula (1), it can be seen that formula (3) has an additional term α compared to formula (1). dtc (T ref (t)-T ref (0)).
[0036] Assuming that the reference temperature changes linearly with power, the reference temperature can be calculated using the following formula (4).
[0037]
[0038] In formula (4), T hfp This is the reference temperature at full power; T hzpThis is the reference temperature at zero power. Pr is the relative power, expressed as %FP.
[0039] When the nuclear power unit is in reactor-following mode, the reactor power changes with the turbine power. Therefore, before the turbine load changes, the reactor is in a steady state and the xenon is in equilibrium. Within about 30 minutes after the turbine load changes, the xenon change can be well approximated as a linear change. Thus, formula (3) can be rewritten as formula (5).
[0040]
[0041] Within a few minutes (e.g., less than 10 minutes) after a change in turbine load, the reactor thermal power tends to stabilize at a new level (denoted as P(∞)). Taking the derivative of equation (5) with respect to time t, we obtain the expression for k. Substituting this expression into equation (5) and combining it with equation (4), we obtain equation (6).
[0042]
[0043] Approximate the power integral of formula (6) about 10 minutes after the turbine load changes, and obtain the final expression of the reactivity coefficient ratio as shown in formula (7).
[0044]
[0045] In formula (7), t1 is the time when the reactor thermal power tends to a new level (i.e., P(∞)) after the turbine load changes. Comparing formula (7) and formula (2), it can be seen that formula (7) has an additional correction parameter Z compared to formula (2), as shown in formula (8) below.
[0046]
[0047] Accordingly, formula (9) is obtained by combining formula (2), formula (7) and formula (8).
[0048]
[0049] For example, the design value of the reactivity coefficient ratio is 2.9482. Taking the reactivity coefficient measurement test of Fuqing U6C1 as an example, the reactivity coefficient ratio calculated based on formula (2) and formula (7) is shown in Table 1 below.
[0050] Table 1 shows the reactivity coefficient ratios calculated based on formulas (2) and (7), respectively.
[0051]
[0052] As can be seen from the data in Table 1, the deviation between the reactivity coefficient ratio calculated based on formula (2) and the design value is 13.6%, and the deviation between the reactivity coefficient ratio calculated based on formula (7) and the design value is 8.5%. Therefore, it can be seen that the reactivity coefficient ratio calculation method of nuclear power plant provided in the embodiments of this application can obtain a reactivity coefficient ratio with smaller error.
[0053] Based on the above formulas (7) to (9), at least one embodiment of this application provides a method for calculating the reactivity coefficient ratio of a nuclear power plant. Figure 1 The diagram shown is a flowchart illustrating a method for calculating the reactivity ratio of a nuclear power plant according to an embodiment of this application. The execution entity of this calculation method can be a processor or a server, etc. The calculation method includes the following steps.
[0054] S100: Obtain the reactor thermal power Pr(t) at the current time t, the reactor thermal power Pr0 at the initial time, and the average reactor coolant temperature T at the current time t. avg (t), the average reactor coolant temperature at the initial moment T0, and the rate of change of the average reactor coolant temperature at t=∞. The time t1 for the reactor thermal power to change from Pr0 to Pr(∞).
[0055] In some embodiments, the average temperature T of the reactor coolant can be used as a reference. avg From the curve about time, we can obtain D by fitting. ∞ .
[0056] S200: Obtain the Doppler power coefficient α dpc Doppler temperature coefficient α dtc Full power reference temperature T hfp and the reference temperature T for zero power hzp .
[0057] In some embodiments, the operator or processor, etc., can find α from the design documents. dtc α dpc T hfp and T hzp Theoretical data, etc.
[0058] S300: Based on Pr(t), Pr0, T avg (t), T0, D ∞ , t, t1, α dtc α dpc T hfp and T hzp The final reactivity coefficient of the nuclear power plant at the current time t is calculated using formula (7).
[0059] According to the technical solution provided in the embodiments of this application, the final reactivity coefficient ratio of the nuclear power plant at the current time t is obtained by using formula (7) derived through rigorous steps and mathematical methods, thereby making the error of the final reactivity coefficient ratio smaller and the accuracy higher, which is conducive to using the final reactivity coefficient ratio to more accurately verify whether the reactor core meets the design requirements.
[0060] Figure 2 The diagram shown is a flowchart illustrating a method for calculating the reactivity ratio of a nuclear power plant according to another embodiment of this application. Figure 2 The embodiment shown is Figure 1 A variation of the illustrated embodiment. For example... Figure 2 As shown, with Figure 1 The difference in the illustrated embodiment is that steps S310 to S330 are Figure 1 A specific implementation of step S300 in the illustrated embodiment.
[0061] S310: Based on Pr(t), Pr0, T avg (t), T0, D ∞ The initial reactivity coefficient of the nuclear power plant at the current time t is calculated using formula (2), based on t, t1, and t2.
[0062] S320: According to T hzp T hfp α dtc and α dpc The correction parameter Z is calculated by combining formula (8).
[0063] It should be noted that steps S310 and S320 can be performed in a specific order or simultaneously; this application embodiment does not impose any specific limitations on this.
[0064] S330: Based on the initial reactivity coefficient ratio of the nuclear power plant at the current time t. And Z, combined with formula (9), the final reactivity coefficient ratio of the nuclear power plant at the current time t is calculated.
[0065] According to the technical solution provided in the embodiments of this application, the initial reactivity coefficient ratio is calculated separately. And the correction parameter Z, and based on the initial reactivity coefficient ratio And the correction parameter Z is calculated to obtain On the one hand, it provides an alternative way to calculate the final reactivity ratio of a nuclear power plant at the current time t, which helps to simplify the calculation method of the final reactivity ratio. On the other hand, if steps S310 and S320 are performed simultaneously, it helps to increase the rate at which the final reactivity ratio of the nuclear power plant at the current time t is calculated.
[0066] Figure 3 The diagram shows a schematic of a nuclear power plant reactivity ratio calculation device according to an embodiment of this application. The calculation device 100 includes an acquisition module 110 and a calculation module 120. The acquisition module 110 is used to acquire the reactor thermal power Pr(t) at the current time t, the reactor thermal power Pr0 at the initial time, and the average reactor coolant temperature T at the current time t. avg (t), the average reactor coolant temperature at the initial moment T0, and the rate of change of the average reactor coolant temperature at t=∞. The time t1 for the reactor thermal power to change from Pr0 to Pr(∞) was determined, and the Doppler power coefficient α was obtained. dpc Doppler temperature coefficient α dtc Full power reference temperature T hfp and the reference temperature T for zero power hzp The calculation module 120 is used to calculate Pr(t), Pr0, and T. avg (t), T0, D ∞ , t, t1, α dtc α dpc T hfp and T hzp The final reactivity coefficient of the nuclear power plant at the current time t is calculated using formula (7).
[0067] In at least one embodiment of this application, the calculation module 120 is further configured to calculate based on Pr(t), Pr0, and T. avg (t), T0, D ∞ The initial reactivity coefficient of the nuclear power plant at the current time t is calculated using formula (2), based on t, t1, and t2. According to T hzp T hfp α dtc and α dpc The correction parameter Z is calculated using formula (8); according to And Z, calculated using formula (9)
[0068] The computing device is the same as the device corresponding to the nuclear power plant reactivity coefficient ratio calculation method provided in the above-described embodiments of this application, and therefore can at least achieve the above-described corresponding technical effects, which will not be elaborated here.
[0069] Figure 4 The diagram shown is a block diagram of an electronic device provided in one embodiment of this application.
[0070] Reference Figure 4The electronic device 10 includes a processor 11 and a memory 12. The memory 12 is used to store instructions executable by the processor 11, such as application programs. There can be one or more processors 11. The application programs stored in the memory 12 can include one or more modules, each corresponding to a set of instructions. Furthermore, the processor 11 is configured to execute instructions to perform the aforementioned method for calculating the nuclear power plant reactivity ratio.
[0071] Electronic device 10 may also include a power supply component configured for power management, a wired or wireless network interface configured to connect electronic device 10 to a network, and an input / output (I / O) interface. Electronic device 10 can operate on an operating system, such as Windows Server, stored in memory 12. TM Mac OSX TM Unix TM Linux TM FreeBSD TM Or similar.
[0072] A non-transitory computer-readable storage medium, when the instructions in the storage medium are executed by the processor of the aforementioned electronic device 10, enables the electronic device 10 to execute a method for calculating the reactivity ratio of a nuclear power plant. This calculation method is executed by an agent program and includes: obtaining the reactor thermal power Pr(t) at the current time t, the reactor thermal power Pr0 at the initial time, and the average reactor coolant temperature T at the current time t. avg (t), the average reactor coolant temperature at the initial moment T0, and the rate of change of the average reactor coolant temperature at t=∞. The time t1 for the reactor thermal power to change from Pr0 to Pr(∞) is used to obtain the Doppler power coefficient α. dpc Doppler temperature coefficient α dtc Full power reference temperature T hfp and the reference temperature T for zero power hzp According to Pr(t), Pr0, T avg (t), T0, D ∞ , t, t1, α dtc α dpc T hfp and T hzp The final reactivity coefficient of the nuclear power plant at the current time t is calculated using formula (7).
[0073] Those skilled in the art will recognize that the algorithmic steps of the various examples described in conjunction with the embodiments disclosed in this application can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.
[0074] In the several embodiments provided in this application, it should be understood that the disclosed computing methods and computing devices can be implemented in other ways. For example, the computing device embodiments described above are merely illustrative. For instance, the division of modules is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple modules may be combined or integrated into another system, or some features may be ignored or not executed.
[0075] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program verification codes, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.
[0076] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working processes of the computing devices and electronic devices described above can be referred to the corresponding processes in the foregoing computing method embodiments, and will not be repeated here.
[0077] It should be noted that the combination of the technical features in the embodiments of this application is not limited to the combination methods described in the embodiments of this application or the combination methods described in specific embodiments. All technical features described in this application can be freely combined or combined in any way, unless they contradict each other.
[0078] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications or equivalent substitutions made within the spirit and principles of this application should be included within the protection scope of this application.
Claims
1. A method for calculating the reactivity ratio of a nuclear power plant, characterized in that, include: Obtain the reactor thermal power Pr(t) at the current time t, the reactor thermal power Pr0 at the initial time, and the average reactor coolant temperature T at the current time t. avg (t), the average reactor coolant temperature at the initial moment T0, and the rate of change of the average reactor coolant temperature at t=∞. The time t1 during which the reactor thermal power changes from Pr0 to Pr(∞); Obtain the Doppler power coefficient α dpc Doppler temperature coefficient α dtc Full power reference temperature T hfp Total temperature coefficient and the reference temperature T for zero power hzp ; Based on Pr(t), Pr0, T avg (t), T0, D ∞ , t, t1, α dtc α dpc , T hfp and T hzp The final reactivity coefficient of the nuclear power plant at time t was calculated to be... ,in, 。 2. The calculation method according to claim 1, characterized in that, The terms are based on Pr(t), Pr0, and T. avg (t), T0, D ∞ , t, t1, α dtc α dpc T hfp and T hzp The final reactivity coefficient of the nuclear power plant at time t was calculated to be... include: Based on Pr(t), Pr0, T avg (t), T0, D ∞ The initial reactivity coefficient of the nuclear power plant at the current time t is calculated using t, t1, and t2. ,in, ; According to T hzp T hfp α dtc and α dpc The correction parameter Z is calculated, where, ; according to And Z, calculated ,in, .
3. A device for calculating the reactivity ratio of a nuclear power plant, characterized in that, include: The acquisition module is used to acquire the reactor thermal power Pr(t) at the current time t, the reactor thermal power Pr0 at the initial time, and the average reactor coolant temperature T at the current time t. avg (t), the average reactor coolant temperature at the initial moment T0, and the rate of change of the average reactor coolant temperature at t=∞. The time t1 during which the reactor thermal power changes from Pr0 to Pr(∞) is determined, and the Doppler power coefficient α is obtained. dpc Doppler temperature coefficient α dtc Full power reference temperature T hfp Total temperature coefficient and the reference temperature T for zero power hzp ; The calculation module is used to calculate Pr(t), Pr0, and T. avg (t), T0, D ∞ , t, t1, α dtc α dpc , T hfp and T hzp The final reactivity coefficient of the nuclear power plant at time t was calculated to be... ,in, 。 4. A computer-readable storage medium having executable instructions stored thereon, characterized in that, When the executable instructions are executed by the processor, they implement a method for calculating the reactivity ratio of a nuclear power plant as described in claim 1 or 2.
5. An electronic device, characterized in that, include: A processor for executing a method for calculating the reactivity ratio of a nuclear power plant as described in claim 1 or 2; as well as Memory for storing the executable instructions of the processor.