CPFD simulation of fluidized bed-based gas cooler
Abstract
Fluidization technology is extensively used in numerous industries for various processes including waste-to-energy conversion, chemical synthesis, granulation, drying etc. Fluidized bed systems are used for these applications, offering even heat distribution and effective energy transmission for thermal systems. The addition or extraction of heat is essential for accomplishing desired reactions and controlling the entire process.
One of the leading industries is engaged in performing research and development (R&D) operations to efficiently capture carbon dioxide (CO2). In this process, the exhaust gases need to be cooled down from a temperature of 400 ℃ to 100 ℃ or lower utilizing an existing coolant. This study aims to examine and simulate the available data using CPFD Barracuda VR® to create a more accurate and realistic model of a gas cooler.
This thesis aims to study literature, developing a bubbling fluidized bed, computing the cooling load and tube length, finding the flowrate of the coolant to design an optimal gas cooler according to the fluidized bed principle, where cooling tubes are immersed in the dense region of the fluidized bed. The hot gas is introduced from the bottom, and it cools down because of heat exchange between the coolant and the fluidization gas, as well as between the coolant and the solid particles in the bed.
CPFD Barracuda VR® simulation version 23.1.0 and Techplot 360 is used for simulation and post processing of data. Thermal calculation of the gas cooler is done by NTU method.
The findings of this study shows that the cooling load obtained from calculation is 742.6 J/s which is very close to the simulation result 750 J/s. The heat transfer area, the internal cooling tubes length and coolant flow rate is found to be approximately 49500 mm2, 3221 mm and 12.78 kg/h respectively and vertical tubes shows better performance compared to horizontal tubes alignment.