EXPERIMENTAL INVESTIGATION ON PRESSURE OSCILLATIONS CAUSED BY CONDENSATION INDUCED WATER HAMMER IN A HORIZONTAL PIPE
The condensation induced water hammer (CIWH) phenomenon often occurs during the steam-water direct contact condensation process, which may cause serious damage to the pipes and related system. In this paper, an experimental investigation was performed to study the CIWH phenomenon caused by steam-water direct contact condensation in a horizontal pipe. Firstly, the entire CIWH process was captured by a high speed video camera and its pressure fluctuation was synchronously measured. Four typical flow patterns were observed during the CIWH process: stratification flow, wave flow, slug flow and bubble collapse. Bubble collapse would generate a high pressure peak. Besides, the radial propagation characteristic of pressure oscillation was researched. There all appeared an obvious pressure peak at three radial positions. The pressure peaks of bottom and side were nearly the same, however, the pressure peak of pipe top was obviously higher than those of the other two positions. Finally, it was found that, at a low water temperature, the maximum peak of six axial measuring points gradually increased with steam mass flux increasing. However, when water temperature was high, maximum peak of six axial positions would increase first and then decrease with a maximum pressure peak of 10MPa.