In the paper, the results of RANS calculations of turbulent convection in silicon melt, obtained using several eddy-viscosity turbulence models, have been compared with previously published ILES eddy-resolving calculation data for similar conditions. A turbulence model was chosen for its subsequent problem-oriented modification with the algebraic introduction of factors that could produce the required anisotropy of the Reynolds stress tensor and the turbulent heat flux vector including in the Reynolds-averaged equations of momentum and energy. As applied to the problems of calculating the convection in crystal growth furnace crucibles using the Czochralski method, it was shown the expediency of taking either the one-equation k-model or the two-equation k-ε model as the initial RANS-model for modification.