Influence of different parameters on the tube-to-bed heat transfer coefficient in a gas-solid fluidized bed heat exchanger

In this paper a combined use of CFD techniques and Design of Experiments is proposed in order to study the significance of different variables on the heat transfer coefficient in a gas-solid fluidized bed heat exchanger. Initially a computational model was developed using Ansys Fluent and validated in order to represent the system under study. Then, this model was used to complete the runs of a 2(5-1) fractional factorial design, in which the response variable was the heat transfer coefficient and factors were: particle diameter, particle thermal conductivity, gas velocity, diameter of the heat transfer tubes and distance between tubes. The results of 16 simulation were used to create different models in which the significance of each coefficient was analyzed. Particle diameter proved to be the parameter that influenced the most the response variable, while gas velocity and solid thermal conductivity showed little effect on the heat transfer coefficient.