Hydro- and thermodynamics of a polydisperse vapor-drop mixture in the channel of regasifier-heater of liquefied natural gas

Abstract

The flow modes of a vapor-drop mixture in a regasifier-heater of liquefied natural gas are numerically studied on the basis of the model that takes into account polydispersity, power, and thermal interaction of phases, processes of breakup, coalescence, evaporation of droplets, and condensation of steam. The dynamics of the carrier medium is described by the system of Navier-Stokes equations for a compressible gas taking into account the exchange of mass, momentum, and energy with a dispersed phase that includes several fractions differing in the size of droplets. Each fraction is described by a system of equations consisting of the continuity equation for the average density, the conservation equations for the momentum components, and the thermal energy conservation equation taking into account the interfacial exchange of mass, momentum, and energy with the carrier medium. Systems of equations of motion for the carrier medium and fractions of the dispersed phase are solved by the explicit McCormack method with the spatial operator splitting in directions and a scheme of nonlinear correction. At each time step, the main part of the computational algorithm is supplemented with models of breakup, coalescence, evaporation of droplets and vapor condensation followed by correction of the hydro- and thermodynamic parameters of the mixture. The calculation of the flow modes of the vapor-drop mixture in the channel of the regasifier-heater of liquefied natural gas is performed based on the described model.