Experimental research on double-hole steam jets dcc heat transfer characteristics under stable condensation pattern

Abstract

The multi-hole spargers are widely used to discharge the high temperature and high pressure steam for depressurization in most engineering applications due to its high efficiency in heat and mass transfer. However, the steam condensation microscopic mechanisms are very complicated, especially for the multi-hole conditions. In this study, the double-hole spraying steam direct contact condensation (DCC) mechanism and heat transfer characteristics are researched based on the scaled IRWST & ADS experimental facility. The double-hole condensation flow regimes are distinguished on the condensation flow patterns diagram, and the steam condensation analytical models are then developed with characteristic parameters including L, Rex, Rx, δ etc. to quantitatively describe the double-hole condensation features. New empirical correlation for predicting the double-hole steam penetration length L is proposed. Moreover, special temperature distributions along both the steam plumes centerline and middle line reflect the interactions between the adjacent steam plumes, especially for the ellipsoidal plume pattern. In essential, the specific temperature variations reflect the equilibrium and transformation between the thermal dynamic energy and kinetic energy. Finally, the heat transfer coefficients for the double-hole steam condensation are calculated based on the steam plume analytical models. The analysis indicates that the double-hole steam condensation heat transfer coefficients are in same order of magnitude with the single-hole stable condensation case, whereas the lower boundary of heat transfer coefficients deceases to some extent. It provides experimental references for the operation and design of the actual industrial steam condensation applications.