Method for measuring the power tilt ratio in a pressurized water reactor core quadrant

Abstract

This invention specifically relates to a method for measuring the quadrant power tilt ratio of a pressurized water reactor core, comprising the following steps: S101, based on the power distribution test data of the pressurized water reactor at various power levels, calculating the temperature difference ΔT between the thermocouple thermometer temperature at the core outlet and the core inlet temperature at various power levels of the pressurized water reactor. i With each fuel assembly containing a thermocouple thermometer, the power p i The correspondence f i And the power of all fuel assemblies in each quadrant j of the reactor core and P Qi The reactor core contains thermocouple thermometers in each quadrant j, and the fuel assembly power and P... Tj Ratio K j S102. Based on the power distribution data under the operating power of the pressurized water reactor, combined with f i and K j The power tilt ratio (QPTR) of the core in each quadrant is calculated under the operating power of the pressurized water reactor. This invention uses f... i Calculate the power p of each fuel assembly containing a thermocouple thermometer. i Reduce the calculation bias of the core quadrant power tilt ratio; consider K j This reduces the calculation bias of the core quadrant power tilt ratio.

Description

Technical Field

[0001] This invention relates to the field of temperature measurement instruments for nuclear power plants, and in particular to a method for measuring the quadrant power tilt ratio of a pressurized water reactor core. Background Technology

[0002] Pressurized water reactor (PWR) nuclear power plants require real-time measurement of core power distribution, primarily including core nuclear power, core axial power deviation, and core quadrant power tilt ratio. Among these, the core quadrant power tilt ratio is a crucial component of core nuclear power measurement and calculation, and its monitoring is subject to strict requirements in relevant nuclear power plant operating technical specifications.

[0003] The "Operating Technical Specifications" require that when the unit's operating power exceeds 50% of its rated thermal power, the core quadrant power tilt ratio must be within the operational limits, specifically <1.02 when the unit is operating at its rated thermal power. However, when the alarm system is inoperable, the core quadrant power tilt ratio must be calculated at least every 12 hours for pressurized water reactors in steady-state operation. When a power range channel is inoperable and its thermal power exceeds 75% of its rated thermal power, the core quadrant power tilt ratio must be confirmed at least every 12 hours using a portable core detector or a core thermocouple thermometer.

[0004] The current industry practice for calculating the core quadrant power tilt ratio using core thermocouple thermometers involves calculating the temperature difference ΔT between the core outlet and inlet thermocouples, then using the average thermocouple temperature difference ΔT across all core quadrants to calculate the average enthalpy rise ΔH of the fuel assembly with thermocouple thermometers in each quadrant. Finally, the average enthalpy rise ΔH corresponding to each core quadrant is equated to the distributed power P of each core quadrant. Qj This allows for the calculation of the core quadrant power tilt ratio.

[0005] The current conventional method of calculating the core quadrant power tilt ratio using core thermocouple thermometers has two technical drawbacks. The first drawback is that the temperatures measured by multiple thermocouple thermometers in the pressurized water reactor's hot, zero-power state exhibit a certain degree of deviation. During the core power increase, the thermocouple thermometers rise by approximately 30-40°C, and this deviation further widens at full power. The measurement error of the thermocouple thermometers is therefore relatively large. The second technical drawback is that directly equating the average enthalpy rise ΔH of the fuel assemblies with thermocouple thermometers in each core quadrant to the power and P of the fuel assemblies in each core quadrant has two technical drawbacks. Qj This does not take into account the power of all fuel assemblies in each quadrant of the reactor core and P. Qj The reactor core contains thermocouple thermometers, fuel assemblies, power, and P in each quadrant. Tj Ratio K jThe core power tilt ratio varies and is not constant across different quadrants. These two technical limitations result in a large deviation in the core quadrant power tilt ratio calculated using core thermocouple thermometers, which cannot meet the practical working requirements for calculating the core quadrant power tilt ratio using core thermocouple thermometers in daily operations. Summary of the Invention

[0006] One objective of this invention is to provide a method for measuring the quadrant power tilt ratio of a pressurized water reactor core, thereby solving the problem of the temperature difference ΔT between the thermocouple temperatures at the core outlet and the core inlet temperature in existing pressurized water reactor core quadrant power tilt ratio measurement methods. i The average enthalpy rise ΔH of the fuel assemblies containing thermocouple thermometers in each quadrant of the reactor core is directly calculated and directly equivalent to the power and P of the fuel assemblies in each quadrant of the reactor core. Qj This leads to a large deviation in the core quadrant power tilt ratio calculated using core thermocouple thermometers. The temperature difference ΔT between the core outlet thermocouple thermometer temperature and the core inlet temperature is addressed. i The measured power p of each fuel assembly containing thermocouples and thermometers in a pressurized water reactor is compared with that of the actual pressurized water reactor. i Perform data processing and calculate ΔT i With p i The correspondence f i , use f i Calculate the power p of each fuel assembly containing a thermocouple thermometer. i This reduces the calculation bias of the core quadrant power tilt ratio.

[0007] The second objective of this invention is to provide a method for measuring the quadrant power tilt ratio of a pressurized water reactor core, which solves the problem in existing methods where the average enthalpy rise ΔH of the fuel assemblies containing thermocouple thermometers in each quadrant of the core is directly equivalent to the power of the fuel assemblies in each quadrant and P. Qj It did not consider the power of all fuel assemblies in each quadrant of the reactor core and P. Qj The reactor core contains thermocouple thermometers, fuel assemblies, power, and P in each quadrant. Tj Ratio K j The different and non-constant values ​​in each quadrant of the reactor core lead to a large deviation in the core quadrant power tilt ratio calculated using core thermocouple thermometers. This issue needs to be addressed by considering the power of all fuel assemblies and P in each core quadrant. Qj The reactor core contains thermocouple thermometers, fuel assemblies, power, and P in each quadrant. Tj Ratio K j This reduces the calculation bias of the core quadrant power tilt ratio.

[0008] The pressurized water reactor core quadrant power tilt ratio measurement method of the present invention has a small calculation deviation of the core quadrant power tilt ratio, which meets the actual working requirements of calculating the core quadrant power tilt ratio using a core thermocouple thermometer in daily use.

[0009] To achieve the above objectives, the present invention provides the following technical solution:

[0010] A method for measuring the quadrant power tilt ratio of a pressurized water reactor core includes the following steps:

[0011] S101. Based on the power distribution test data of the pressurized water reactor at various power levels, calculate the temperature difference ΔT between the thermocouple thermometer temperature at the core outlet and the core inlet temperature at various power levels of the pressurized water reactor. i With each fuel assembly containing a thermocouple thermometer, the power p i The correspondence f i And the power of all fuel assemblies in each quadrant j of the reactor core and P Qj The reactor core contains thermocouple thermometers in each quadrant j, and the fuel assembly power and P... Tj Ratio K j ;

[0012] S102. Based on the power distribution data under the operating power of the pressurized water reactor, combined with f i and K j Calculate the power tilt ratio (QPTR) of the core in each quadrant under the operating power of the pressurized water reactor.

[0013] Furthermore, the method for measuring the quadrant power tilt ratio of a pressurized water reactor core also includes:

[0014] S103. Update f in real time based on the latest test data of power distribution of pressurized water reactor at various power levels. i and K j .

[0015] Further, S101 includes the following steps:

[0016] S1011. Calculate the temperature difference ΔT between the thermocouple temperature at the core outlet and the core inlet temperature at various power levels of the pressurized water reactor. i ;i is the fuel assembly number containing a thermocouple thermometer;

[0017] S1012. Calculate the power p of each fuel assembly containing thermocouples and thermometers at various power levels of a pressurized water reactor. i ;

[0018] S1013. Calculate ΔT for each power level of the pressurized water reactor. i With p i Correspondence ΔT i =f i (p i );

[0019] S1014. Calculate the power and P of all fuel assemblies in each quadrant j of the reactor core. Qj The reactor core contains thermocouple thermometers in each quadrant j, and the fuel assembly power and P... Tjproportion

[0020] In one embodiment, S1011, the temperature difference ΔT between the thermocouple temperature at the core outlet and the core inlet temperature is calculated when the pressurized water reactor is at 0%, 30%, 75%, and 100% full power. i .

[0021] Furthermore, the core inlet temperature is the average of the temperatures of each thermocouple thermometer at the core inlet.

[0022] In one embodiment, S1012, the power p of the pressurized water reactor containing the thermocouple thermometer fuel assembly is calculated at 0%, 30%, 75%, and 100% full power. i .

[0023] Further, in S1012, the power p of the pressurized water reactor containing thermocouple thermometer fuel assemblies is calculated at various power levels. i It includes the following steps:

[0024] During the power distribution test of the pressurized water reactor at various power levels, the core fuel assembly power p of the pressurized water reactor at various power levels was obtained through thermal balance measurements. th ;

[0025] The relative power of each fuel assembly containing thermocouples and thermometers in the core of a pressurized water reactor at various power levels. Substitute into the formula The calculated power p of the pressurized water reactor with thermocouple thermometer fuel assembly at various power levels was obtained. i ;

[0026] Each fuel assembly in the reactor core contains thermocouples and thermometers. (Relative power) It is the ratio of the power of each fuel assembly containing a thermocouple thermometer in the reactor core to the average power of the fuel assembly in the reactor core.

[0027] In one embodiment, S1013, ΔT is calculated for each power of the pressurized water reactor. i and p i The data was processed, and the ΔT value for each power output of the pressurized water reactor was calculated. i With p i Correspondence ΔT i =f i (p i );f i For p i A first-order function.

[0028] In one embodiment, S1014, using the most recent 100% full-power power distribution test data of the pressurized water reactor, the power of all fuel assemblies and P in each quadrant j of the reactor core are calculated. Qj The reactor core contains thermocouple thermometers in each quadrant j, and the fuel assembly power and P...Tj proportion The fuel assemblies in each quadrant of a pressurized water reactor do not include the central set of fuel assemblies; a pressurized water reactor is divided into four quadrants, j being 1 to 4.

[0029] Further, S102 includes the following steps:

[0030] S1021. Real-time calculation of the temperature difference ΔT between the thermocouple thermometers at the core outlet and the core inlet temperature under pressurized water reactor operating power. i ;

[0031] S1022, According to the formula ΔT i =f i (p i Real-time calculation of the power p of each fuel assembly containing thermocouples and thermometers at the operating power of the pressurized water reactor. i ;

[0032] S1023, Based on the power p of each fuel assembly containing thermocouples and thermometers under the operating power of the pressurized water reactor. i Real-time calculation of the power of the pressurized water reactor core in each quadrant j containing the thermocouple thermometer fuel assembly and P under the operating power of the pressurized water reactor. Tj ;

[0033] S1024, According to the formula Real-time calculation of the power of all fuel assemblies and P in each quadrant j of the pressurized water reactor core under the operating power of the pressurized water reactor. Qj ;

[0034] S1025, According to the formula Real-time calculation of the power tilt ratio (QPTR) of each quadrant of the pressurized water reactor core under operating power conditions.

[0035] Beneficial technical effects of the present invention:

[0036] The pressurized water reactor core quadrant power tilt ratio measurement method of the present invention uses the temperature difference ΔT between the thermocouple thermometer temperature at the core outlet and the core inlet temperature. i The measured power p of each fuel assembly containing thermocouples and thermometers at various power levels in a pressurized water reactor. i Perform data processing and calculate ΔT i With p i The correspondence f i , use f i Calculate the power p of each fuel assembly containing a thermocouple thermometer. i To reduce errors; consider the power and P of all fuel assemblies in each quadrant j of the reactor core. Qj The reactor core contains thermocouple thermometers in each quadrant j, and the fuel assembly power and P... Tj Ratio K j Eliminates the deviation introduced by the asymmetry of thermocouple thermometer position; fi and K j The calculation results are updated in real time based on the latest test data on power distribution of pressurized water reactors at various power levels, ensuring high accuracy. Attached Figure Description

[0037] Figure 1 A flowchart of an embodiment of the pressurized water reactor core quadrant power tilt ratio measurement method of the present invention;

[0038] Figure 2 This is a power distribution diagram of a 1 / 4 core fuel assembly in one embodiment;

[0039] Figure 3 This is a diagram showing the distribution of thermocouples at the reactor core outlet in one embodiment. Detailed Implementation

[0040] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein in the specification is for the purpose of describing particular embodiments only and is not intended to be limiting of the application; the term "comprising" and any variations thereof in the specification, claims and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0041] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0042] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings and specific embodiments.

[0043] See Figure 1 This embodiment provides a method for measuring the quadrant power tilt ratio of a pressurized water reactor core, including the following steps:

[0044] S101. Based on the power distribution test data of the pressurized water reactor at various power levels, calculate the temperature difference ΔT between the thermocouple thermometer temperature at the core outlet and the core inlet temperature at various power levels of the pressurized water reactor. i With each fuel assembly containing a thermocouple thermometer, the power p i The correspondence f i And the power of all fuel assemblies in each quadrant j of the reactor core and P Qj The reactor core contains thermocouple thermometers in each quadrant j, and the fuel assembly power and P... Tj Ratio K j ;

[0045] S102. Based on the power distribution data under the operating power of the pressurized water reactor, combined with f i and K j Calculate the power tilt ratio (QPTR) of the core in each quadrant under the operating power of the pressurized water reactor;

[0046] S103. Update f in real time based on the latest test data of power distribution of pressurized water reactor at various power levels. i and K j .

[0047] In this embodiment, S101 includes the following steps:

[0048] S1011. Calculate the temperature difference ΔT between the thermocouple temperature at the core outlet and the core inlet temperature at various power levels of the pressurized water reactor. i ;i is the fuel assembly number containing a thermocouple thermometer;

[0049] S1012. Calculate the power p of each fuel assembly containing thermocouples and thermometers at various power levels of a pressurized water reactor. i ;

[0050] S1013. Calculate ΔT for each power level of the pressurized water reactor. i With p i Correspondence ΔT i =f i (p i );

[0051] S1014. Calculate the power and P of all fuel assemblies in each quadrant j of the reactor core. Qj The reactor core contains thermocouple thermometers in each quadrant j, and the fuel assembly power and P... Tj proportion

[0052] Since the fuel assembly loading scheme affects the core power distribution, it further affects the relationship between the core outlet thermocouple temperature and the corresponding fuel assembly power. To reduce this impact, in this embodiment, in S1011, the temperature difference ΔT between the 28 thermocouple temperatures at the core outlet and the core inlet temperature is calculated for the pressurized water reactor at 0%, 30%, 75%, and 100% full power. i The core inlet temperature is the average value of the temperatures measured by each thermocouple thermometer at the core inlet.

[0053] In this embodiment, in S1012, the power p of the pressurized water reactor containing thermocouple thermometer fuel assemblies is calculated at 0%, 30%, 75%, and 100% full power. i It includes the following steps:

[0054] During the power distribution tests of the pressurized water reactor (PWR), the core fuel assembly power p was obtained through thermal balance measurements at 0%, 30%, 75%, and 100% full power. th ;

[0055] The relative power of the pressurized water reactor core containing thermocouple thermometer fuel assemblies was compared at 0%, 30%, 75%, and 100% full power. Substitute into the formula The calculated power p of the pressurized water reactor with thermocouple thermometer fuel assembly at 0%, 30%, 75%, and 100% full power were obtained. i ;

[0056] Each fuel assembly in the reactor core contains thermocouples and thermometers. (Relative power) It is the ratio of the power of each fuel assembly containing a thermocouple thermometer in the reactor core to the average power of the fuel assembly in the reactor core.

[0057] Figure 2 The figure shows the power distribution of fuel assemblies in a quarter core of a pressurized water reactor at a certain power level. The values ​​in the figure represent the relative power of each fuel assembly containing a thermocouple thermometer in a quarter core of the pressurized water reactor at a certain power level.

[0058] In this embodiment, in S1013, ΔT under various power levels of the pressurized water reactor... i and p i The data was processed, and the ΔT of the pressurized water reactor at 0%, 30%, 75%, and 100% full power was calculated. i With p i Correspondence ΔT i =f i (p i );f i For p i A first-order function.

[0059] f i A detailed breakdown based on each power level is necessary to improve accuracy. i For p i The first-order function can meet the actual working needs of calculating the core quadrant power tilt ratio using a core thermocouple thermometer in daily work.

[0060] The correspondence between each thermocouple thermometer and the fuel assembly f i There is a difference; in this embodiment, there are 28 thermocouple thermometers at the core outlet, therefore there are 28 corresponding relationships f. i .

[0061] In this embodiment, in S1014, the power distribution data of the most recent 100% full power test of the pressurized water reactor is used to calculate the power of all fuel assemblies and P in each quadrant j of the reactor core. QjThe reactor core contains thermocouple thermometers in each quadrant j, and the fuel assembly power and P... Tj proportion

[0062] See Figure 2 The pressurized water reactor unit is divided into 30 fuel assemblies in each quadrant. The fuel assemblies in each quadrant do not include the central fuel assembly. The power and P of all fuel assemblies in each quadrant j of the reactor core... Qj It is the sum of the power of the 30 fuel assemblies in each quadrant j of the reactor core;

[0063] See Figure 3 Each quadrant j of the reactor core contains 7 fuel assemblies with thermocouple thermometers. The power and P of the fuel assemblies with thermocouple thermometers in each quadrant j of the reactor core are... Tj The sum of the power of the 7 fuel assemblies containing thermocouples and thermometers in each quadrant j of the reactor core; the reactor core is divided into four quadrants, j being 1 to 4.

[0064] In this embodiment, S102 includes the following steps:

[0065] S1021. Real-time calculation of the temperature difference ΔT between the thermocouple thermometers at the core outlet and the core inlet temperature under pressurized water reactor operating power. i ;

[0066] S1022, According to the formula ΔT i =f i (p i Real-time calculation of the power p of each fuel assembly containing thermocouples and thermometers at the operating power of the pressurized water reactor. i ;

[0067] S1023, Based on the power p of each fuel assembly containing thermocouples and thermometers under the operating power of the pressurized water reactor. i Real-time calculation of the power of the pressurized water reactor core in each quadrant j containing the thermocouple thermometer fuel assembly and P under the operating power of the pressurized water reactor. Tj ;

[0068] S1024, According to the formula Real-time calculation of the power of all fuel assemblies and P in each quadrant j of the pressurized water reactor core under the operating power of the pressurized water reactor. Qj ;

[0069] S1025, According to the formula Real-time calculation of the power tilt ratio (QPTR) of each quadrant of the pressurized water reactor core under operating power conditions.

[0070] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. A method for measuring the quadrant power tilt ratio of a pressurized water reactor core, characterized in that, Includes the following steps: S101. Based on the power distribution test data of the pressurized water reactor at various power levels, calculate the temperature difference between the thermocouple thermometer temperature at the core outlet and the core inlet temperature at various power levels of the pressurized water reactor. With each fuel assembly containing a thermocouple thermometer, the power Correspondence and each quadrant of the reactor core All fuel components power and With each quadrant of the reactor core Contains thermocouples, thermometers, fuel assembly, power and proportion ; S102. Based on the power distribution data under the operating power of the pressurized water reactor, combined with... and Calculate the power tilt ratio of the core in each quadrant under the operating power of the pressurized water reactor. ; Number the fuel assembly containing the thermocouple thermometer.

2. The method for measuring the quadrant power tilt ratio of a pressurized water reactor core according to claim 1, characterized in that, Also includes: S103. Updated in real time based on the latest power distribution test data of pressurized water reactors at various power levels. and .

3. The method for measuring the quadrant power tilt ratio of a pressurized water reactor core according to claim 1, characterized in that, S101 includes the following steps: S1011. Calculate the temperature difference between the thermocouple temperature at the core outlet and the core inlet temperature at various power levels of the pressurized water reactor. ; Numbering of fuel assemblies containing thermocouple thermometers; S1012. Calculate the power of each fuel assembly containing thermocouples and thermometers at various power levels of a pressurized water reactor. ; S1013, Calculate the power of the pressurized water reactor at various power levels. and Correspondence ; S1014. Calculate the core quadrants. All fuel components power and With each quadrant of the reactor core Contains thermocouples, thermometers, fuel assembly, power and proportion .

4. The method for measuring the quadrant power tilt ratio of a pressurized water reactor core according to claim 3, characterized in that, S1011, Calculate the temperature difference between the thermocouple temperature at the core outlet and the core inlet temperature of the pressurized water reactor at 0%, 30%, 75%, and 100% full power. .

5. The method for measuring the quadrant power tilt ratio of a pressurized water reactor core according to claim 3 or 4, characterized in that, The core inlet temperature is the average value of the temperatures of each thermocouple thermometer at the core inlet.

6. The method for measuring the quadrant power tilt ratio of a pressurized water reactor core according to claim 3, characterized in that, S1012, Calculate the power of the pressurized water reactor containing thermocouple thermometer fuel assemblies at 0%, 30%, 75%, and 100% full power. .

7. The method for measuring the quadrant power tilt ratio of a pressurized water reactor core according to claim 3 or 6, characterized in that, S1012, Calculate the power of the pressurized water reactor with each fuel assembly containing thermocouple thermometers at various power levels. This includes the following steps: During the power distribution test of the pressurized water reactor at various power levels, the power of the core fuel assembly of the pressurized water reactor at each power level was obtained through thermal balance measurement. ; The relative power of each fuel assembly containing thermocouples and thermometers in the core of a pressurized water reactor at various power levels. Substitute into the formula The power of the pressurized water reactor with thermocouple thermometer fuel assemblies at various power levels was calculated. ; Each fuel assembly in the reactor core contains thermocouples and thermometers. (Relative power) It is the ratio of the power of each fuel assembly containing a thermocouple thermometer in the reactor core to the average power of the fuel assembly in the reactor core.

8. The method for measuring the quadrant power tilt ratio of a pressurized water reactor core according to claim 3, characterized in that, S1013, for pressurized water reactors at various power levels and The data was processed and calculated for each power output of the pressurized water reactor. and Correspondence ; for A first-order function.

9. The method for measuring the quadrant power tilt ratio of a pressurized water reactor core according to claim 3, characterized in that, S1014, using the most recent 100% full-power power distribution test data of the pressurized water reactor, calculate the core quadrants. All fuel components power and With each quadrant of the reactor core Contains thermocouples, thermometers, fuel assembly, power and proportion The fuel assemblies in each quadrant of a pressurized water reactor do not include the central set of fuel assemblies; a pressurized water reactor is divided into four quadrants. 1 4.

10. The method for measuring the quadrant power tilt ratio of a pressurized water reactor core according to claim 1, characterized in that, S102 includes the following steps: S1021. Real-time calculation of the temperature difference between the thermocouple thermometers at the core outlet and the core inlet temperature under pressurized water reactor operating power. ; S1022, According to the formula Real-time calculation of the power of each fuel assembly containing thermocouple thermometers at the operating power of the pressurized water reactor. ; S1023, Based on the power of each fuel assembly containing thermocouple thermometers under the operating power of the pressurized water reactor. Real-time calculation of pressurized water reactor operating power in each quadrant of the reactor core Contains thermocouples, thermometers, fuel assembly, power and ; S1024, According to the formula Real-time calculation of pressurized water reactor operating power in each quadrant of the reactor core All fuel components power and ; S1025, According to the formula Real-time calculation of the power tilt ratio of the core in each quadrant under the operating power of the pressurized water reactor .

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