Local heat and mass transfer characteristics of different channel configurations in polysilicon chemical vapor deposition reactor

Abstract

As the crucial material of photovoltaic field, the development of polysilicon has attracted intense attention on reducing its cost and improving the polysilicon chemical vapor deposition (CVD) performance. Two-dimensional numerical models have been developed to investigate the local heat and mass transfer performance of polysilicon CVD system by introducing wave-like and trapezoid-like obstacles in the gas flow channels. Effects of different channel configurations on the local velocity, temperature, concentrations of six components, Nusselt number (Nu), Sherwood number (Sh) and seven coordinate angles along the flow direction are presented and detailed analyzed. The disturbing obstacles increase both the local and total Nu, as well as Sh. The seven coordinate angles caused by velocity vector, temperature gradient, and concentration gradient increase near the disturbing structures and decrease out of the disturbing obstacles. However, the disturbing obstacles decrease the total intersection angles leading better heat and mass transfer performance. In brief, compared to conventional straight channel, the proposed channels increase the gas flow velocity and, hence, improved the silicon CVD characteristics.