Convective heat transfer across silicon rods under uniform wall heat flux in a laboratory-scale Siemens reactor

The effects of operating and geometric parameters on convective heat transfer (CHT) in Siemens reactor with a laboratory-scale are investigated. A dimensionless analysis of the CHT is performed considering the flow characteristics, rod diameter (d), rod length (L), number of rods, and the distance between adjacent silicon rods. A dimensionless parameter (Hou) is proposed to represent the number of rods and the distance between adjacent rods. Additionally, three dimensionless parameters that affect the CHT, namely, the Rayleigh number, d/L, and Hou, are obtained. The two-factor interaction effects of the dimensionless parameters on the CHT are analyzed, and their relationships are determined for calculating the CHT flux. Based on these relationships, the Nusselt number is calculated for 7- and 8-rod laboratory-scale Siemens reactors, and the relative errors between the predicted and calculated results are 1.4 and 3.2 %, respectively.