Method for calculating weight power of reactor of nuclear power station

Abstract

The invention relates to the field of reactor operation and safety, in particular to a nuclear power station reactor weight power calculation method. The method comprises the following steps: 1, checking a reactor power measurement mode of a nuclear power unit, and classifying the reactor power measurement mode into directly measured reactor power and indirectly measured reactor power; 2, finding out the error of the directly measured reactor power, and meanwhile, calculating the error of the indirectly measured reactor power; 3, calculating the weight coefficient of each power according to the error of each measured reactor power obtained in the step 1; and 4, taking the weight coefficients into consideration and summing the power measurement values of the reactors to obtain the weight power of the reactors. According to the invention, the power parameters monitored in the operation process of the reactor can be ensured to have high reliability and accuracy, and the core requirements of safe, stable and reliable operation of the nuclear power station are met.

Description

Technical Field

[0001] The invention relates to the field of reactor operation and safety, and in particular to a method for calculating weighted power of a nuclear power plant reactor. Background Art

[0002] Reactor power is an important parameter for the operation control and monitoring of nuclear power units. It represents the heat generated by the nuclear power plant reactor per unit time and is often used for reactor status monitoring, operation control, shutdown protection, and efficiency calculation. According to different measurement methods, the common nuclear power plant reactor power is divided into the power measured by the external nuclear measurement system (hereinafter referred to as N NFME Power), power measured by the core measurement system (hereinafter referred to as N SPND Power), power calculated by primary circuit parameters (hereinafter referred to as N 1C Power), power calculated by the secondary circuit parameters (hereinafter referred to as N 2C Power), etc. The reactor powers obtained by the above-mentioned different measurement methods can be used for nuclear power plant operation control and monitoring. However, due to the different measurement methods, there are certain deviations between various reactor powers, and each has its own advantages and disadvantages in terms of response speed, accuracy and reliability. Monitoring personnel often need to conduct certain analysis before they can determine a more accurate reactor power. At the same time, due to the failure of some instruments, the reactor power measured by a certain measurement method may also have a certain deviation, affecting the judgment and control of the monitoring personnel. Considering the importance of reactor power to the operation control and monitoring of nuclear power plants, it is crucial to the safe operation of nuclear power plants to be able to monitor reactor power in a timely, reliable and accurate manner. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a method for calculating the weighted power of a nuclear power plant reactor, which can ensure that the power parameters monitored during the operation of the reactor have high reliability and accuracy, and meet the core requirements of safe, stable and reliable operation of the nuclear power plant.

[0004] The present invention provides a method for calculating the weighted power of a nuclear power plant reactor, comprising the following steps:

[0005] Step 1: Check the reactor power measurement methods of the nuclear power unit and classify them into directly measured reactor power and indirectly measured reactor power;

[0006] Step 2: Find out the error of the directly measured reactor power and calculate the error of the indirectly measured reactor power;

[0007] Step 3: Calculate the weight coefficient of each power through the errors of various measured reactor powers obtained in step 1;

[0008] Step 4: Consider the weight coefficient of each reactor power measurement value and sum them up to obtain the reactor weighted power.

[0009] Optionally, in step one, the directly measured reactor power includes power measured by an external nuclear measurement system and power measured by an internal nuclear measurement system.

[0010] Optionally, in step one, the indirectly measured reactor power includes: power calculated by primary loop parameters and power calculated by secondary loop parameters.

[0011] Optionally, in step 2, the error of directly measured reactor power is found based on the factory design document of the instrument or system.

[0012] Optionally, in step 2, the method for calculating the error of the indirectly measured reactor power includes:

[0013] For any addition and subtraction formula: X = U ± V, where the error of the value X is Δx, the error of the value U is Δu, and the error of the value V is Δv, there is the following relationship:

[0014] Δx 2 =Δu 2 +Δv 2

[0015] For any multiplication formula: X = U·V, where the error Δx of the value X, the error Δu of the value U, and the error Δv of the value V, there is the following relationship:

[0016] (Δx / X) 2 =(Δu / U) 2 +(Δv / V) 2 .

[0017] Optionally, in step 2, the method for calculating the error of the indirectly measured reactor power includes: a method for calculating the power error calculated for the primary loop parameters and a method for calculating the power error calculated for the secondary loop parameters;

[0018] The power calculation method for primary circuit parameter calculation is:

[0019]

[0020] Where F is the coolant flow rate through the reactor, m 3 / h;

[0021] ρ is the density of the coolant passing through the reactor, kg / m 3 ;

[0022] h hot is the outlet enthalpy of the coolant passing through the reactor, kJ / kg;

[0023] h cold is the inlet enthalpy of the coolant passing through the reactor, kJ / kg;

[0024] The error ΔN of the power calculated by the primary circuit parameters 1c The calculation method is as follows:

[0025]

[0026] ΔF is the coolant flow error through the reactor,

[0027] Δρ is the density error of the coolant passing through the reactor

[0028] Δ(h hot -h cold ) is the error of the difference between the outlet enthalpy and the inlet enthalpy of the coolant passing through the reactor. The power calculation method for the second loop parameter calculation is:

[0029] N 2c =N SG +N LCQ -N RCP

[0030] Among them, N SG is the thermal power of the steam generator, MW;

[0031] N LCQ is the blowdown heat of the steam generator, MW;

[0032] N RCP is the heat brought into the main pump, MW;

[0033] The error ΔN of the power calculated by the secondary circuit parameters 2c The calculation method is as follows:

[0034]

[0035] ΔN SG is the thermal power error of the steam generator,

[0036] ΔN LCQ The blowdown heat error of the steam generator;

[0037] ΔN RCP Heat error introduced by the main pump.

[0038] Optionally, in step three,

[0039] The calculation method of weight coefficient is:

[0040]

[0041] Among them, W KA weighting factor for reactor power measured in some way.

[0042] ΔN K The reactor power error measured in different ways.

[0043] Optionally, in step 4, the calculation method of the reactor weighted power is:

[0044]

[0045] Where n refers to the total number of measured reactor powers;

[0046] N K Reactor power measured in different ways.

[0047] Compared with the prior art, the method for calculating the weighted power of a nuclear power plant reactor of the present invention can combine the existing various reactor power measurement results and their deviations of nuclear power plants to calculate a more accurate reactor power; the reactor power calculated using the method has good anti-interference performance. The method of the present invention ensures that the power parameters monitored during the operation of the reactor have high reliability and accuracy, meeting the core requirements of safe, stable and reliable operation of nuclear power plants. DETAILED DESCRIPTION

[0048] In order to further understand the present invention, the embodiments of the present invention are described below in conjunction with examples, but it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, rather than limiting the present invention.

[0049] An embodiment of the present invention discloses a method for calculating weighted power of a nuclear power plant reactor, comprising the following steps:

[0050] Step 1: Check the reactor power measurement methods of the nuclear power unit and classify them into directly measured reactor power and indirectly measured reactor power;

[0051] Step 2: Find out the error of the directly measured reactor power and calculate the error of the indirectly measured reactor power;

[0052] Step 3: Calculate the weight coefficient of each power through the errors of various measured reactor powers obtained in step 1;

[0053] Step 4: Consider the weight coefficient of each reactor power measurement value and sum them up to obtain the reactor weighted power.

[0054] The present invention is based on a domestic VVER-1000 pressurized water reactor nuclear power unit, and the weighted power calculation method is applicable to other nuclear power units with multiple reactor power measurement methods.

[0055] In order to ensure the accuracy of the calculation of the reactor weighted power, it is important to accurately calculate the weight coefficient of each measured power. Since the most important characteristics of the reactor power of a nuclear power plant need to have high accuracy and reliability, the calculation of the weight coefficient in the present invention is based on the uncertainty of the power measurement of each power (i.e., the measurement error). The power with a large measurement error should account for a lower proportion in the weighted power. On the contrary, the power with a small measurement error should account for a larger proportion in the weighted power. Only in this way can the reliability and accuracy of the reactor weighted power be guaranteed. Taking a domestic VVER-1000 pressurized water reactor nuclear power unit as an example, it has N NFME Power, N SPND Power, N 1C Power, N 2C The four types of reactor power can be measured accurately by giving the errors of the above measured powers, and then the weight coefficient of each power can be calculated.

[0056] Reactor power monitoring can be divided into two categories: one is direct measurement, such as N NFME Power, N SPND Power, which is obtained by measurement and conversion by a dedicated instrument or system; the other is an indirect measurement value, such as N 1C Power, N 2C Power is calculated based on the measurement values ​​of multiple special instruments through a certain calculation formula or method. For direct measurement values, manufacturers generally provide the measurement error of the relevant instrument or system when supplying, that is, the error of the direct measurement value; but for indirect measurement values, manufacturers only provide the error of the basic value of the measurement of the relevant special instrument when supplying. In order to obtain the error of the indirect measurement value, it is necessary to calculate it through the error transfer formula in the mathematical method. The error transfer formula is:

[0057] For any addition and subtraction formula: X = U ± V, where the error of the value X is Δx, the error of the value U is Δu, and the error of the value V is Δv, there is the following relationship:

[0058] Δx 2 =Δu 2 +Δv 2

[0059] For any multiplication formula: X = U·V, where the error Δx of the value X, the error Δu of the value U, and the error Δv of the value V, there is the following relationship:

[0060] (Δx / X) 2 =(Δu / U) 2 +(Δv / V) 2 .

[0061] In order to further understand the present invention, the method for calculating the weighted power of a nuclear power plant reactor provided by the present invention is described in detail below in conjunction with embodiments. The protection scope of the present invention is not limited by the following embodiments.

[0062] Example 1

[0063] Step 1: Check the reactor power measurement methods of the nuclear power units and classify them into directly measured reactor power and indirectly measured reactor power according to their different measurement methods;

[0064] Reactor power measured by different methods is referred to as N k , where “k” refers to the kth way.

[0065] The directly measured reactor power includes the power measured by the external nuclear measurement system and the power measured by the internal nuclear measurement system.

[0066] The indirectly measured reactor power includes: power calculated by primary loop parameters and power calculated by secondary loop parameters.

[0067] Step 2: For directly measured reactor power, find out the error of the directly measured value through the manufacturer's supply documents;

[0068] The error of different reactor powers is referred to as ΔN k , where “k” refers to the kth way.

[0069] The calculation method of the error of the indirectly measured reactor power includes: a calculation method of the power error calculated for the primary loop parameters and a calculation method of the power error calculated for the secondary loop parameters;

[0070] The power calculation method for primary circuit parameter calculation is:

[0071]

[0072] Where F is the coolant flow rate through the reactor, m 3 / h;

[0073] ρ is the density of the coolant passing through the reactor, kg / m 3 ;

[0074] h hot is the outlet enthalpy of the coolant passing through the reactor, kJ / kg;

[0075] h cold is the inlet enthalpy of the coolant passing through the reactor, kJ / kg;

[0076] The error ΔN of the power calculated by the primary circuit parameters 1c The calculation method is as follows:

[0077]

[0078] ΔF is the coolant flow error through the reactor,

[0079] Δρ is the density error of the coolant passing through the reactor

[0080] Δ(h hot -h cold ) is the error between the outlet enthalpy and the inlet enthalpy of the coolant passing through the reactor

[0081] The power calculation method for the secondary circuit parameter calculation is:

[0082] N 2c =N SG +N LCQ -N RCP

[0083] Among them, N SG is the thermal power of the steam generator, MW;

[0084] N LCQ is the blowdown heat of the steam generator, MW;

[0085] N RCP is the heat brought into the main pump, MW;

[0086] The error ΔN of the power calculated by the secondary circuit parameters 2c The calculation method is as follows:

[0087]

[0088] ΔN SG is the thermal power error of the steam generator,

[0089] ΔN LCQ The blowdown heat error of the steam generator;

[0090] ΔN RCP Heat error introduced by the main pump.

[0091] Step 3: Calculate the corresponding weight coefficient according to the errors of power measurement in the above-mentioned various ways. The calculation method is as follows:

[0092]

[0093] Among them, W K A weighting factor for reactor power measured in some way.

[0094] ΔN K The reactor power error measured in different ways.

[0095] Step 4: Calculate the reactor weighted power N. The calculation method is as follows:

[0096]

[0097] Where n refers to the total number of measured reactor powers;

[0098] N K Reactor power measured in different ways.

[0099] The above embodiments are only used to help understand the method and core idea of ​​the present invention. It should be noted that, for those skilled in the art, several improvements and modifications can be made to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

[0100] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for calculating weighted power of a nuclear power plant reactor, characterized in that: The following steps are involved: Step 1: Check the reactor power measurement methods of the nuclear power unit and classify them into directly measured reactor power and indirectly measured reactor power; Step 2: Find out the error of the directly measured reactor power and calculate the error of the indirectly measured reactor power; Step 3: Calculate the weight coefficient of each power through the errors of various measured reactor powers obtained in step 1; Step 4: Consider the weight coefficient of each reactor power measurement value and sum them up to obtain the reactor weighted power.

2. The method for calculating weighted power of a nuclear power plant reactor according to claim 1, characterized in that: In the step 1, the directly measured reactor power includes the power measured by the external nuclear measurement system and the power measured by the internal nuclear measurement system.

3. The method for calculating weighted power of a nuclear power plant reactor according to claim 1, characterized in that: In the step 1, the indirectly measured reactor power includes: the power calculated by the primary loop parameters and the power calculated by the secondary loop parameters.

4. The method for calculating weighted power of a nuclear power plant reactor according to claim 2, characterized in that: In the step 2, the error of the directly measured reactor power is found based on the factory design document of the instrument or system.

5. The method for calculating weighted power of a nuclear power plant reactor according to claim 3, characterized in that: In the step 2, the method for calculating the error of the indirectly measured reactor power includes: For any addition and subtraction formula: X = U ± V, where the error of the value X is Δx, the error of the value U is Δu, and the error of the value V is Δv, there is the following relationship: Δx 2 =Δu 2 +Δv 2 For any multiplication formula: X = U·V, where the error Δx of the value X, the error Δu of the value U, and the error Δv of the value V, there is the following relationship: (Δx / X) 2 =(Δu / U) 2 +(Δv / V) 2 。 6. The method for calculating weighted power of a nuclear power plant reactor according to claim 3, characterized in that: In the step 2, the calculation method of the error of the indirectly measured reactor power includes: a calculation method for the power error calculated for the primary loop parameters and a calculation method for the power error calculated for the secondary loop parameters; The power calculation method for primary circuit parameter calculation is: Where F is the coolant flow rate through the reactor, m 3 / h; ρ is the density of the coolant passing through the reactor, kg / m 3 ; h hot is the outlet enthalpy of the coolant passing through the reactor, kJ / kg; h cold is the inlet enthalpy of the coolant passing through the reactor, kJ / kg; The error ΔN of the power calculated by the primary circuit parameters 1c The calculation method is as follows: ΔF is the coolant flow error through the reactor, Δρ is the density error of the coolant passing through the reactor Δ(h hot -h cold ) is the error between the outlet enthalpy and the inlet enthalpy of the coolant passing through the reactor The power calculation method for the secondary circuit parameter calculation is: N 2c =N SG +N LCQ -N RCP Among them, N SG is the thermal power of the steam generator, MW; N LCQ is the blowdown heat of the steam generator, MW; N RCP is the heat brought into the main pump, MW; The error ΔN of the power calculated by the secondary circuit parameters 2c The calculation method is as follows: ΔN SG is the thermal power error of the steam generator, ΔN LCQ The blowdown heat error of the steam generator; ΔN RCP Heat error introduced by the main pump.

7. The method for calculating weighted power of a nuclear power plant reactor according to claim 1, characterized in that: In the step three, The calculation method of weight coefficient is: Among them, W K A weighting factor for reactor power measured in some way. ΔN K The reactor power error measured in different ways.

8. The method for calculating weighted power of a nuclear power plant reactor according to claim 1, characterized in that: In step 4, the calculation method of the reactor weighted power is: Where n refers to the total number of measured reactor powers; N K Reactor power measured in different ways.

Images