A comprehensive method for judging the failure cause of the sealing ring of the eh system of a nuclear power plant

Abstract

The invention belongs to the technical field of nuclear power facility detection, and particularly relates to a comprehensive judgment method for a nuclear power facility sealing ring failure reason. The process parameters and the operating conditions of a sealing ring are known; appearance inspection is carried out on the failed sealing ring; methods such as a three-dimensional stereo microscope and a scanning electron microscope are adopted to carry out more detailed observation on the failed sealing ring and a sealing groove; one or more characterization method is adopted to carry out component analysis on a sealing medium; one or more characterization method is adopted to analyze the components and the performance of the failed sealing ring; and whether the size of the sealing ring and the size of the groove meet design requirements is inspected. Through integrating the above analysis steps, main reasons for the failure of the sealing ring are determined from the phenomenon to the essence. After the EH system failed sealing ring is systematically and effectively analyzed, the sealing ring failure reasons can be judged accurately and quickly, and targeted prevention is further carried out. The method also has practical reference value in safety use of the sealing ring in other fields such as power, petrochemical industry, chemical industry and metallurgy.

Description

technical field [0001] The invention belongs to the technical field of nuclear power device detection, and in particular relates to a method for judging the cause of failure of a sealing ring of a nuclear power device, in particular to a method for judging the cause of failure of an O-shaped sealing ring in an EH system of a steam turbine. Background technique [0002] Nuclear power steam turbine units generally use a digital electro-hydraulic control system (DEH) to regulate and control the start, stop, normal operation and accident conditions of the steam turbine. The DEH system controls the speed, load and pressure of the generator set through the control of the main steam valve and the adjustment of the valve opening. The hydraulic control system (EH) is an important part of the DEH system, mainly including the oil supply system, the actuator and the emergency blocking system. Its function is to complete the conversion of the DEH command signal to the steam turbine valve...

AI Technical Summary

Problems solved by technology

Once the oil pressure drops, the lifting force of the actuator will become smaller, and the main valve cannot be opened normally, and even cause the trip of the steam turbine, which will cause the reactor to shut down

The pipe fittings of the oil pipeline of the EH system are usually sealed with O-rings. Therefore, whether the O-rings can be sealed normally and effectively will have a great impact on the stability of the oil pressure in the system and the safe operation of the entire unit.

[0003] There have been several cases of premature failure of O-ring seals in the EH system of nuclear power plants. For example, the service life of O-rings for oil motors in the EH system of a nuclear power plant imported from a coastal area is one cycle (12-14 months). Leakage occurred within a month, and the factory had to manually reduce the unit power, isolate the oil motor and carry out maintenance, which had a major impact on the normal operation of the nuclear power unit

However, there is still a lack of systematic and effective failure analysis methods for O-rings at home and abroad, and it is difficult to accurately analyze the cause of failure.

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