EXPERIMENTAL DIRECT-CONTACT HEAT TRANSFER IN UPWARD AIR-WATER DEVELOPING ANNULAR-FLOW

Some experimental results are presented in order to quantify the impac t of several operating parameters on the direct contact heat and mass transfer processes between hot water and cooling air, flowing upward i nside a vertical, adiabatic, circular tube (12 mm i.d.), in the develo ping co-current annular flow regime. The proposed temperature measurem ent technique for the gas phase is based on the energy and mass balanc e equations applied to proper control volumes. The data processing met hod seems to be particularly suitable for the performance evaluation o f the direct contact heat transfer occurring between the phases during the flow. Further developments are expected in the characterisation o f different injection systems used for the mixing of two fluids in the rmodynamic non-equilibrium conditions.