Description of Dynamic Behavior of a Fluidized Bed with Biomass Fuels by Shannon Entropy Increment Analysis

摘要

The concept of Shannon entropy increment analysis, that is, Shannon entropy increment (SEI) and Shannon entropy increment rate (SEIR) of pressure fluctuations, was developed to recognize the dynamic behavior of fluidizing of cylinder-shaped biomass fuels (2.6 mm in transection diameter and 6 mm in length). Experiments were carried out in a visible biomass fluidized bed with a cross-section of 0.1 m by 0.03 m and height of 0.5 m. The condition of high Shannon entropy was defined as a high level of uncertainty in the ability to predict the dynamic behavior of gas-solid flow. The SEI and SEIR were regarded as the change of uncertainty and the change speed of uncertainty with operating condition, respectively. The results showed that the flow patterns of gas/cylinder-shaped biomass transited in turn with under-fluidization, steady fluidization, and turbulent fluidization when the superficial gas velocities increased. Both SEI and SEIR were pronounced with these flow patterns and transitions. The lowest values of SEI and SEIR were found in the flow pattern of steady fluidization, whereas the highest values of both parameters were found in the flow pattern of turbulent fluidization.