This work investigates double-diffusive natural convection in a V-shaped sump with a control volume method based on an unstructured triangular grid Two types of boundary conditions involving temperature and concentration distributions are considered herein. Analysis results indicate that the calculated vortex flow for the linear type boundary condition might be ascribed to a numerical error. For another type of abrupt change boundary condition, the concentration gradient is higher than the temperature gradient near the top of the V-shaped sump. A thin Boundary layer exists in the pure solutal convection. Furthermore, double-diffusive natural convection is demonstrated herein.