Online diagnosis method for effectiveness states of thermocouples of reactor core of pressurized water reactor nuclear power plant

Abstract

The invention belongs to effectiveness diagnosis method for signals, in particular to an online diagnosis method for effectiveness states of thermocouples of a reactor core of a pressurized water reactor nuclear power plant. The online diagnosis method includes firstly, judging whether the quantity of the thermocouples meets requirements or not; secondly, computing average values T1 of measurement data of the available thermocouples; thirdly, judging whether a working condition of a reactor meets thermocouple signal online diagnosis conditions or not; and fourthly, judging the effectiveness of signals of the thermocouples. The online diagnosis method has the advantages that the effectiveness states of the thermocouples of the reactor core of the pressurized water reactor nuclear power plant can be continuously diagnosed in an online manner, thermocouple data with excessively high measurement errors are timely eliminated, and integral measurement accuracy of a system is improved to meet requirements of an SOP (standard operation procedure). In addition, the system can guarantee that thermocouples which are mistakenly eliminated can be timely corrected, and numbers of failed thermocouples can be timely provided, so that the failed thermocouples can be replaced during shut-down refueling.

Description

technical field [0001] The invention belongs to a signal validity diagnosis method, in particular to an online diagnosis method for the validity state of a core thermocouple of a pressurized water reactor nuclear power plant. Background technique [0002] In nuclear power plants, a large number of core thermocouples are usually installed for core temperature measurement. For example, Ling Ao Phase II nuclear power plant has 38 thermocouples for measuring the coolant temperature at the core outlet. These thermocouples work under high temperature, high pressure and high radiation environmental conditions for a long time. The harsh environmental conditions will cause irreversible damage to the thermocouples, resulting in insulation degradation and thermoelectric potential drift. In addition, since thermocouples will introduce various defects during the manufacturing and installation process, these defects may cause large drift of individual thermocouples during operation. In t...

AI Technical Summary

Problems solved by technology

Because the traditional core thermocouple signal processing method cannot identify and eliminate the thermocouples with degraded performance, it cannot meet the requirements of SOP. In addition, because the thermocouples with degraded performance cannot be identified in time, they cannot be replaced during refueling during shutdown

[0004] Due to the arrangement of a large number of redundant measurement channels in the reactor, processing the data of these redundant measurement channels is the most direct way to improve the accuracy of the data, but due to the differences in the core outlet temperature itself, especially in the accident state And under some transient conditions, the state in the core is very complicated, so it is necessary to develop a system that can diagnose and eliminate failed thermocouples without allowing real measurement data to be mistakenly eliminated.