  We present high resolution numerical simulations of convection in multiphase
flows (boiling) using a novel algorithm based on a Lattice Boltzmann method. We
first validate the thermodynamical and kinematical properties of the algorithm.
Then, we perform a series of 3d numerical simulations at changing the mean
properties in the phase diagram and compare convection with and without phase
coexistence at $Ra \sim 10^7$. We show that in presence of nucleating bubbles
non-Oberbeck Boussinesq effects develops, mean temperature profile becomes
asymmetric, heat-transfer and heat-transfer fluctuations are enhanced. We also
show that small-scale properties of velocity and temperature fields are
strongly affected by the presence of buoyant bubble leading to high
non-Gaussian profiles in the bulk.
