The process in the countercurrent humidifier of HAT cycle involves the evaporation of atomized liquids in a turbulent environment. To allow an optimization of such process and provide data for the validation of numerical calculation, the spray evaporation in a countercurrent air stream was studied experimentally. Measurements were taken for different flow parameters, such as airflow rate and liquid flow rate in order to provide reliable data. Phase-Doppler anemometry (PDA) was applied to obtain the spatial change of the droplet size spectrum in the flow field and to measure droplet size-velocity correlations. These local measured profiles of droplet mean velocities, velocity fluctuations and droplet mean diameters were obtained by averaging over all droplet size classes. Moreover, DualPDA signal processing allows accurate determination of the droplet mass flux and local concentration, from which the global evaporation rates could also be determined. These local temperature profiles were measured using the thermocouple and acquired by data acquisition system based on virtual instrument (VI) technology.
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