Direct Contact Condensation of Steam Jet in a Pool

Abstract

Abstract The phenomena of direct contact condensation (DCC) of a steam jet discharged in a water pool occur due to the actuation of steam discharging devices submerged in a pool in many industrial processes. There are practically two kinds of technical concerns to consider. The first is the thermal mixing in the water pool, and the other is the thermo-hydraulically induced mechanical loads acting on the structures of relevant systems. The two concerns are interrelated with each other and can be well described only if the local behavior of condensing steam jets and the resultant turbulent jet in a pool is well understood. In this paper, the DCC-related thermo-fluid dynamic features are discussed focusing on these two concerns. The fundamental characteristics of condensing steam jets, such as local characteristics of condensing jets and the resultant turbulent jet, are reviewed, both of which importantly affect the macroscopic circulation motion in a pool. Here the local behavior of condensing jets includes the shapes of steam jet cavity, temperature and pressure profiles in a steam jet region, jet expansion and penetration length, interfacial mass and heat transfer around the cavity, dynamic aspect of steam jet condensation, and the condensation regime map. Then a global motion analysis of thermal mixing in a pool is discussed from the viewpoints of the local hot spot and the thermal stratification with some practical applications to engineering design in mind.