Experimental study on the correlation between bubble heat transfer coefficient and pressure oscillation frequency in the bubbling regime of steam jet

Direct contact condensation of steam–water is widely applied in the industrial and food fields. In this work, the bubble condensation pressure oscillation frequency and heat transfer coefficient in vertical upward and downward directions are studied. The steam mass flux range is 22.12–50.13 kg m−2 s−1, and the water subcooling degree is 20–40 K. The bubble heat transfer coefficient and the pressure oscillation frequency have a positive correlation in the two steam jet directions. The mechanism of the positive correlation is analyzed. An artificial neural network model is proposed to calculate the bubble heat transfer coefficient. The proposed model can accurately predict the bubble heat transfer coefficient with correlation coefficient R2 = 0.97, which provides a convenient path for obtaining the coefficient of heat transfer.