The AOK-TFR analysis of high temperature gas–solid two-phase flow

Abstract

Due to the increasing scarcity of coal resources, and a drop in the quality of existing power plant coal, much research figure out best configuration of fluidized beds are required. Against this backdrop, this paper uses lignite coal to examine the heating delivery and spray dynamic characteristics of spouted bed. Unlike existing literature focusing on the research of signals of any fixed point under a fixed condition, this paper tests the signals under dynamic conditions that is, with the air temperature constantly rising. The dynamic temperature and pressure fluctuation signals of fixed points were measured and researched. The reason we chose to research dynamic conditions is that the temperature rising process are dynamic. This paper presents an effective quadric time–frequency representations of signal; namely, the Adaptive Optimal Kernel Time–Frequency Representation (AOK TFR) combined with spectral energy and entropy. The analysis focuses on the internal mechanism of pressure fluctuation signals corresponding to different temperature gradient distribution. We also did a regression analysis of the bed temperature and pressure drop. The results suggest that the AOK TFR method can reveal flow characteristics and spray mechanisms of high-temperature gas–solid two-phase flow from different analysis points, and that this method is an effective nonlinear time–frequency method to analyze other two-phase flow processes. There is a high correlation between drops in pressure and temperature when the operating temperature is between 140°C and 350°C.