自然对流欠热沸腾系统声压波动频域分析及工况识别

FREQUENCY DOMAIN ANALYSIS OF SOUND PRESSURE OSCILLATION IN NATURAL CONVECTIVE SUBCOOLED BOILING SYSTEM AND ITS REGIME RECOGNITION

利用计算机数据采集技术获取了自然对流欠热沸腾系统中声压波动的动态信号，通过对典型动态数据的频域分析，结合实测声压时间序列研究，对激波的产生、倍频关系、谱峰聚合等一系列时、频现象的动力学机理进行解释，描述了自然对流欠热沸腾系统的动态发展过程。基于声压频谱，定义并构造了特征向量，通过动态聚类，对该欠热沸腾两相系统的动态过程进行了工况识别，识别结果与对时间序列的定性分析一致，这对构建核安全自动监控系统乃至沸腾两相流工况识别诊断专家系统具有重要意义。

In this paper, dynamical signals of sound pressure oscillation in natural convective subcooled boiling system are obtained by using computer data acquisition technique. Through frequency domain analysis of typical dynamical data, combined with study on the acquired time series of sound pressure,are observed and explained. The time frequency phenomena, such as the onset of shock wave, frequency doubling relation of sound pressure, combination of sound frequency spectrum peaks etc., which describe the characteristics of natural convective subcooled boiling system are presented. Furthermore, based on frequency spectra of sound pressure, related eigen vectors are defined and established and with dynamical clustering method, regime recognition for the dynamical process of system is carried out. Results of recognition are consistent with that of qualitative analysis of time series, which is of great significance for automatic monitoring system of nuclear safety, expertise recognition and diagnostic system of boiling two phase flow regime.