Poly-disperse simulation of condensing steam-water flow inside a large vertical pipe

The condensation of saturated steam bubbles in sub-cooled water inside a vertical pipe is studied by poly-disperse CFD simulations. Six test cases with varied pressure, liquid sub-cooling and diameter of the gas injection orifices are investigated. Baseline closures presented for non-drag forces in previous work are found to be reliable also in non-isothermal cases. The effect of bubble coalescence and breakup is negligible in cases with small orifice diameter. The Ranz-Marshall correlation leads to a global under-estimation of the condensation rate, especially at high pressure levels.