Frequency Analysis of Direct Contact Condensation Using the Wavelet Transform During the Vertical Steam Injection on the Subcooled Water Pool

An experimental investigation has been performed to analyze the frequency associated with pressure, acoustics, and bubble evolution characteristics during the vertical injection of steam into a subcooled water pool. The frequency analysis is crucial for the structural integrity of the pool. The continuous wavelet transform is used for time domain frequency analysis of the data acquired from the pressure transducer and hydrophone at different steam mass flow rates and submergence of pipe outlet within the pool. The range of mass flow rate for the present study is 10–30 kg/hr, and pipe submergence depth is 1–9 cm. The bubble shape continuously changes with time due to the unstable nature of the direct contact condensation (DCC) phenomenon. The analysis shows that the frequency of pressure and acoustic sound signal increases with the mass flow rate. In addition, the analysis has revealed that the pressure spikes appear relatively in shorter time with an increase of mass flow rate in magnitude scalogram. The amplitude of pressure and acoustic signals decreases with the increase of steam mass flow rate.