Abstract
The characteristic of a saturator (a humidification tower), which is used as a humidifier of the AHAT( Advanced Humid Air Turbine) system, were studied. For various pressure ratios (from 8 to 24) of a gas turbine, the required packing height and the exit water temperature from the saturator were analyzed. Thermal efficiency of the system was compared with the simple cycle and the recuperated cycle. The highest thermal efficiency of the system was 54.7% LHV when the pressure ratio was 20. The efficiency can be raised further by cooling blades with humid air. When the packing height of the saturator was changed, the required size of three heat exchangers around the saturator (a recuperator, an economizer and an air cooler) varied. The packing height with which the sum total of the size of the saturator and these heat exchangers become the minimum was 1m when the pressure ratio was 8, and 6m when the pressure ratio was 24.
