Flow morphology and heat transfer analysis during high-pressure steam condensation in an inclined tube part I: Experimental investigations

In this paper, experimental investigations on the flow morphology and heat transfer in a single steam condenser tube are presented, which were performed at the thermal hydraulic test facility COSMEA (COndensation test rig for flow Morphology and hEAt transfer studies). This facility has been setup to study the interrelation of condensation heat transfer with two- phase flow in an isolated single condenser tube that is cooled by forced convection. Studies have been performed for elevated pressures up to 65 bar at saturation conditions and for inlet steam mass flow of up to 1 kg/s and different inlet steam qualities. The wall heat flux is measured with distributed heat flux probe and global condensation rates have been obtained from integral heat and mass balances. As a unique feature the cross-sectional phase distribution has been studied via X-ray computed tomography. The data is going to be used for the validation of numerical simulations with 1D ATHLET and 3D CFD codes as presented in the second part of this paper.