Experimental study on dynamic pressure pulse in direct contact condation of steam jets discharging into subcooled water

The dynamic pressure resulting from direct contact condensation of steam jets discharging into a subcooled water has been measured as a function of steam mass flux and subcooled water temperature. Steam is discharged in a horizontal direction through four different size nozzles placed in the middle of a quenching tank, which contains water at various temperatures. Four different horizontal nozzles with an internal diameter in the range of 5{approx}20mm were used under the various test conditions of the steam mass flux in the wide range of 24{approx}1190 kg/m{sup 2}-s and the pool water temperature in the range of 20{approx}95 .deg. C. It is observed from the test results that the amplitude of dynamic pressure pulse at condensation oscillation condition becomes greater than that at a stable condensation condition of the same pool temperature . The dynamic pressure tends to increase with pool temperature at the beginning. The amplitude reached a peak at a pool temperature around 60 {approx}80.deg. C depending on nozzle size and steam mass flux and then the amplitude decrased rapidly before the pool water reached saturation temperature. The amplitude of the dynamic pressure pulse at the unstable condition reached it peak at the condition of pool temperature 60.deg. C, but the amplitude peack at the stable condition was found at around 80.deg. C. The chugging phenomena have been observed at low steam mass flux (below 80 kg/m{sup 2}-s). The condensation regime map has been constructed by acoustic/visual observations and dynamic pressure behaviors. The condensation regime map consists of six regimes such as chugging, transient chugging, condensation oscillation, stable condensation, bubble condensation oscillation, and interfacial oscillation condensation. As the pool temperature increases above 90 .deg. C the steam discharging into a subcooled water does not condense completely in the pool and part of it escapes through the free surface of water. The transition from condensation socillations to stable condensation takes place at about 230{approx}270 kg/m{sup 2}-s, but this value increase with increasing pool temperature.