Experimental study on stable steam condensation in a quenching tank

Abstract

SUMMARYExperimental study on direct contact condensation (DCC) of a stable steam discharging into a quenching tank with sub-cooled water has been performed for "ve di!erent sizes of horizontal nozzles over a wide range of steam mass #ux and pool temperature conditions. Two di!erent steam jet shapes (conical and ellipsoidal) were typically observed, depending on the steam mass #ux and the pool temperature. The steam jet expansion ratios, the dimensionless steam jet lengths, and the average heat transfer coe$cients were determined and the e!ects of steam mass #ux, pool temperature, and nozzle diameter on these parameters were discussed. Empirical correlations for the dimensionless steam jet length and the average heat transfer coe$cient as a function of steam mass #ux and condensation driving potential were established. The axial and radial temperature distributions in the steam jet and in the surrounding pool water were measured and the e!ects of steam mass #ux, pool temperature, and nozzle diameter on these parameters were also discussed.

Experimental study on pressure and temperature distributions for low mass flux steam jet in subcooled water

“…For stable steam jet in subcooled water, two typical steam plume shapes including conical and ellipsoidal shapes were observed in sonic steam jet by Chun et al [6] and Kim et al [9] , and for the relatively high water temperature, the steam plume was unstable, which led to divergent shape. Wu et al [10] carried out the experiment on supersonic steam jet condensation in subcooled water, and besides the above steam plume shapes another four steam plume shapes were observed, including double expansion-contraction, double expansion-emanative, contraction-expansion-contraction, and contraction-expansion-emanative shapes.…”

“…The pressure distributions in cone jet and the surrounding zone at steam mass flux of 483 kg/m 2 s were given by Giovanni et al [18] , and the pressures were used to evaluate the velocity profiles. Kim et al [9] measured the axial and radial temperature distributions in the steam jet, which described the expansion and compression waves of an under-expanded jet in the case of the ellipsoidal shaped jet. Kim et al [19] conducted an experiment about the turbulent jet flow induced by steam jet at high steam mass flux of 1000 kg/m 2 s and high steam temperature of 166℃, the velocity and temperature distributions were measured, and the general theory of turbulent jet was found to be applicable to the turbulent flows.…”

“…The pressure and temperature characteristics in the steam plume and the surrounding water were measured in order to analyze the flow and heat transfer mechanism [9,16,17] . Youn et al [2] investigated the dynamic pressure oscillation of the chugging region with the water temperature and steam mass flux in the range of 30-80℃ and 10-80 kg/m 2 s, the change of condensation mode was correlated with pressure pulse generation, and the transition regime agreed well with that identified by Chan et al [5] .…”

“…Kerney et al [13] studied the penetration length of steam jet into the subcooled water, and gave a correlation to predict the dimensionless penetration length. The basic correlation was adopted and corrected with the density or pressure by the later researchers according to their experimental data [6,9,10,13,14] . Petrovic [15] presented a model for direct contact condensation of steam in water to predict the steam plume length, and the ellipsoidal model showed the best agreement with experimental data and was considered to be the most appropriate shape for a wide range of data.…”

Pressure oscillation and steam cavity during the condensation of a submerged steam jet

“…For the steam jet condensation, a lot of works have been developed for many years, like the condensation regime (Cho et al, 1998;Petrovic de With et al, 2007;Wu et al, 2009;Song and Kim, 2011), the steam jet pattern (Chun et al, 1996;Wu et al, 2009), the coefficient of heat transfer (Kim et al, 2001;Shah et al, 2010Shah et al, , 2013Patel et al, 2014) and the steam jet condensation load (Chan, 1978;Fukuda, 1982;Simpson and Chan, 1982). When steam is jetted into water and condensed by water, there will generate some pressure impulse in water pool, which is called condensation oscillation.…”