Cooling air system and method for combined cycle power plants

A cooled cooling air (CCA) system (154) is provided for application with gas turbine cycles (10). In an embodiment of the invention, the CCA system includes a shell (158) and tube heat exchanger (160) in which water flow is provided inside the tube(s) and air flow is provided on the shell side. Water (202) exiting the heat exchanger is partially evaporated. Accordingly, the resulting two phase water/(steam flow is admitted to a separator (204) where the steam (164) and water (162) are separated. The saturated steam (164) is flowed to the HRSG (32) whereas the separator water (162) is recycled to the heat exchanger.