Analysis of Two-Phase Flow in Condensers and Evaporators Based on Two-Fluid Models: Numerical Model and Experimental Comparison

A numerical study of the thermal and fluid-dynamic behaviour of the two-phase flow in conducts is presented. The numerical analysis is based on two-fluid models. The model allows consider that liquid and gas have different velocities and temperatures. The numerical simulation has been developed by means of the finite volume technique based on a one-dimensional transient integration of the continuity, momentum and energy equations. The gas distribution into the tube, pressure, velocities and temperatures of the liquid and gas phase are obtained to resolve the differential equations by means of the Newton-Raphson algorithm. The novelty in this work is how two-fluid model describes the distribution of the interface velocity and temperature differences along the two-phase region. The numerical comparative results show the verification of the numerical model developed, while the experimental comparative results validate the simulation. Experimental and analytical data obtained from literature are used in the validation task.