Heat Transfer Modeling and Thermal Analysis for a Fluidized Bed

heat transfer modeling and thermal analysis for a fluidized bed

This paper presents a mathematical model and a computer simulation program for the numerical prediction of the performance of a fluidized bed cooling tower. The mathematical model is based on the heat and mass transfer equations. This model is used to predict the thermal behavior of a fluidized bed cooling tower with experimental data. In this paper experiments have been performed to measure the thermal performance of a fluidized bed cooling tower of 280 mm diameter. Hollow plastic spheres of three different sizes, with diameters of 20, 25 and 37 mm and particle densities ranging from 70 to 325 kg/m3, were investigated as packing materials, and results for static bed heights of 100 mm and 300 mm are reported. Measurements were obtained at an approximately constant inlet hot water temperature of around 42°C and cover a range of water mass flux from 0.3 to 3.6 kg/sm2. Liquid/gas ratios varied between 0.1 and 5.5. Results for thermal performance are presented showing the effects on the cooling tower characteristic, KaV/L, of the different packing elements and of varying water flow rate, air flow rate and the height of the hot water distributor above the bed. This provides a useful semi experimental relation, in the area generally lacking in design and performance data. It has been found that the accuracy of 5% obtained by using the chosen model can be then taken into account whenever this model is used to predict other characteristics related to the fluidized bed cooling tower.