A compact packing humidifier for the micro humid air turbine cycle: Design method and experimental evaluation

The purpose of this research is to develop a compact humidifier with novel ceramic foam corrugated packing, which is conducive to the improvement of the flexibility of humid air turbine cycles, thus has a potential in commercial application. The packing size is calculated with an analytic model based on the Merkel theory and energy effectiveness-NTU function. The simplified structures of the air and water distributors are proposed according to the special characteristics of packing. The evaluation of this humidifier has been carried out by means of experimental data obtained from a mHAT system. Both the steady state performance at off-design conditions and dynamic behavior at start-up process are presented and analyzed. At nominal condition, the humidifier shows a pinch of 12 °C and a relatively pressure loss of 0.59% operating pressure. With the load decreasing from 100% to 50%, the inlet and outlet fluid temperature as well as the outlet air humid ratio will all decrease, but the maximum decrement is not more than 11%. Due to the great thermal capacitance, especially that of the water in its bottom section, a relative slow response of the humidifier has been observed.