This paper presents the results of a numerical study involving the solidification process of nanofluids in spherical cavities. The model was constructed by applying the heat conduction equation in the solid and liquid phases of the domain, including effective thermal conductivity in the liquid phase so as to accommodate the convective terms of the process. The equations of the model were solved using the finite difference method with an implicit discretization scheme and were validated by comparing results with an analytical solution from the literature. This paper seeks to analyze the effect of nanoparticles on the speed of cooling of the liquid phase and of the solidification times of the nanofluid. Four different types of nanofluids were analyzed all of which had water as the base fluid. The results showed that the nanoparticles in the base fluid accelerate the cooling process and decrease the time taken for complete solidification. (C) 2019 Elsevier B.V. All rights reserved.