Application Of Fractal Technology To The Measurement Of Gas-Solid Fluidization

Parameter measurement of fluidization was important and needed to be solved imminently. Many researchers devoted to it but had gained a little achievement because of the complexity of fluidization. In this thesis,flow regime identification and malfunction diagnosis of fluidization were studied with fractal technology,the presented methods for both flow regime identification and malfunction diagnosis were proved of effectivity. main achievements are as following:1. Fractal Brownian Motion(FBM) was made from Gauss Noise and compared with pressure fluctuation signal of gas-solid fluidization,which demonstrated the similarity between the FBM and the signal. Then,Hurst Exponent was calculated from time series of the signal with R/S method. The exponent was applied in research of the identification and the diagnosis.2. Pressure fluctuation signals of fixed bed,bubbling bed and turbulent bed were analyzed with R/S method. The result showed that the Hurst Exponent of the signal have obvious differences between different flow regime. It increased when flow regime was changed from fixed bed to bubbling bed and more from bubbling bed to turbulent,based on which a new method for identification of flow regime was proposed. To improve the accuracies of identification fuzzy technology was introduced. Experimental results showed that the method was effective and the accuracies can get to above 80%.3. Agglomerate particle was put into the fluidization bed to simulate the agglomeration malfunction. It was found that the Hurst exponent decreased when the malfunction happened. A malfunction coefficient was introduced to diagnose the agglomeration malfunction. Experimental results showed that the malfunction coefficient changed more obviously than Hurst exponent did when malfunction happened,the accuracy of diagnosis was 80.8%.