Design Of Pipeline Vibration Detection System For Nuclear Power Plant

Under the background of the green development of "carbon peak" and "carbon neutrality",nuclear power generation has become the most promising power generation mode in China.The pipeline system is an important component in nuclear power plants.In order to facilitate repair and maintenance,pipelines are mostly supported and lifted in nuclear power plants.Compared with the buried pipelines,the supported and lifted pipelines are more susceptible to vibration.Pipeline vibration not only reduces the transportation efficiency of the pipelines,but also causes pipeline damage,leakage,and even safety accidents.In view of this,this paper establishes a dynamic model of the pipeline vibration based on the Flügge motion equations,analyzes the transmission law of the vibration in the pipeline,and designs a pipeline vibration detection system.The experimental research has shown that the system can detect the pipeline vibration in real-time and judge the position and intensity of the vibration source.The research content is of great scientific significance for the safe and stable operation of nuclear power plants.Based on the Flügge motion equations,a dynamic model of the pipeline vibration is established,and the transmission law of the vibration signals in the pipeline is studied.For a pipeline with a length of 2.00 m,a radius of 30.0 mm,and a wall thickness of 1.5 mm,the natural frequency of the pipeline vibration is analyzed.The results have shown that it is di scretely distributed in the range of 20 Hz-10 kHz,and the amplitude of the natural frequency vibration signal can reflect the vibration intensity of the pipeline system.By simulating the pulse input of a free falling mass impacting a pipeline,the acceleration and the attenuation coefficient of the pipeline vibration are analyzed,providing a theoretical basis for the design of the pipeline vibration detection system and the experimental data analysis.Based on PVDF piezoelectric film sensor and taking STM32 as the core processing unit,a pipeline vibration detection system and vibration signal processing algorithms are designed.The system can detect the frequency range of 0.3 Hz to 30 kHz,the acceleration range of ± 10 g,and the sensitivity of 50 mV/g.The system can obtain the natural frequency and the amplitude,attenuation coefficient,propagation speed,propagation direction and other characteristic information at this frequency of the pipeline vibration through embedded self-correlation analysis,cross-correlation analysis,fitting algorithm,Fourier analysis and wavelet analysis,which provides technical support for the subsequent determination of the position and intensity of the vibration source.To verify the feasibility of the pipeline vibration detection system and vibration signal processing algorithms,an experimental system is established and the experimental research is conducted.The research has shown that compared to the moving average method,the vibration signals denoised by the discrete wavelet method are more similar to the original signals and retain more high-frequency information.The single-channel sensor can detect the parameters such as the natural frequency and the amplitude of the pipeline vibration,while the multi-channel sensors can detect the parameters such as the attenuation coefficient and the propagation speed of the vibration signals,so as to determine the position and intensity of the vibration source.The experimental results verify the feasibility of the pipeline vibration detection system.