External Fuel Ball Sensor with Self-Diagnosis for Pebble-Bed Reactors
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Solution Overview
Problem
Conventional fuel ball detecting devices in pebble-bed high temperature gas cooled reactors face issues such as structural complexity, maintenance difficulties, radiation pollution, low electromagnetic compatibility, and failure to generate alarms during faults, leading to counting losses and miscounts due to interference in harsh environments.
Innovation Solution
A fuel ball detecting method and system with a self-diagnosis function, utilizing a pair of detecting coils and a signal processor to generate and process sinusoidal alternating current signals, and a single chip microcomputer to determine the presence of fuel balls and diagnose the functionality of the system components, thereby providing a reliable and interference-resistant solution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional detecting devices are installed inside or via side wall drillings of the pipeline, then fuel ball detection can be achieved, but the gas tightness of the pipeline is compromised and the structure becomes complicated
Solution Approach 1:
The detecting coil is extracted from the pipeline interior or side wall drilling configuration and relocated to the exterior of the pipeline. This allows the pipeline to maintain its intact structure and gas tightness while still enabling fuel ball detection through the pipeline wall, thereby resolving the contradiction between detection capability and structural integrity.
Solution Approach 2:
The pipeline wall itself serves as an intermediary medium that transmits electromagnetic signals from the external detecting coil to the fuel ball inside the pipeline. This eliminates the need for internal sensors or side wall drillings, maintaining gas tightness while enabling detection through the existing pipeline structure.
2Reliability
If sensors are installed inside the pipeline or via drillings, then fuel ball detection is possible, but maintenance becomes difficult and radiation pollution occurs during maintenance
Solution Approach 1:
The sensor is extracted from the hazardous interior environment of the pipeline and positioned externally. This allows maintenance personnel to service the sensor without entering the radiation zone, eliminating radiation pollution during maintenance while preserving detection accuracy through the intact pipeline wall.
Solution Approach 2:
The external sensor configuration allows the detection system to be serviced independently of the pipeline interior conditions. The sensor can be accessed, maintained, and replaced from the external environment, making the system self-servicable without requiring disruption of the pipeline interior or exposure to radiation during maintenance operations.
3Reliability
If the detecting coil contacts the radioactivity fuel ball directly, then detection can be performed, but the working life of the sensor is reduced
Solution Approach 1:
The pipeline wall acts as a protective intermediary barrier that shields the external detecting coil from direct contact with radioactive fuel balls. This allows the sensor to maintain detection capability through the pipeline wall while being protected from radiation damage, thereby extending its working life.
Solution Approach 2:
The detecting coil is taken out from direct exposure to the radioactive environment and positioned externally where it can detect fuel balls through the pipeline wall without direct contact. This extraction from the hazardous environment preserves the sensor's working life while maintaining detection functionality.
4Reliability
If conventional detecting devices are used in the high temperature gas cooled reactor, then fuel ball detection is achieved, but electromagnetic interference causes miscount
Solution Approach 1:
The pipeline wall serves as a shielding intermediary that protects the external detecting coil from electromagnetic interference generated within the reactor environment. This allows accurate fuel ball detection while blocking harmful electromagnetic signals from reaching the sensor, resolving the contradiction between detection accuracy and interference resistance.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The system ensures accurate fuel ball counting, reduces radiation pollution, and generates alarms for faults, improving the reliability and anti-interference capabilities of the fuel ball detection process, ensuring safe reactor operation.
Implementation Method 1
exciting a first detecting coil and a second detecting coil of a fuel ball sensor disposed outside a pipeline by a sinusoidal alternating current
Data Source
AI summary
A fuel ball detecting method and system with a self-diagnosis function are provided. The method includes: exciting a first detecting coil and a second detecting coil of a fuel ball sensor disposed outside a pipeline; obtaining a first voltage signal U1 from the first detecting coil and a second voltage signal U2 from the second detecting coil; processing U1 and U2 by differential amplification, band pass filtering, phase sensitive detection and low pass filtering by a signal processor to obtain a fuel ball waveform signal U0; determining whether the fuel ball passes the pipeline according to U0 by a single chip microcomputer; determining whether the first and the second detecting coils, the signal processor and the single chip microcomputer work normally; outputting a result showing whether the fuel ball passes the pipeline, when the first and the second detecting coils, the signal processor and the single chip microcomputer work normally.