A 40MW-class test facility has been constructed to verify practicability of applying the advanced humid air turbine (AHAT) system to a heavy-duty gas turbine. Verification tests have been carried out from January 2012, and interaction effects between the key components were established.
First, water atomization cooling (WAC) was confirmed to contribute to both increased mass flow rate and pressure ratio for the axial flow compressor. The good agreement between measured and calculated temperatures at the compressor discharge was also confirmed. These results demonstrated the accuracy of the developed prediction model for the WAC.
Second, a control method which realized both flame stability and low NOx emissions was verified. Although the power output and air humidity were lower than the rated values, NOx concentration was about 10 ppm.
Finally, a hybrid nozzle cooling system, which utilized both compressor discharged air and humid air, was developed and tested. The metal surface temperatures of the first stage nozzles were measured, and they were kept under the permissible metal temperature. The measured temperatures on the metal surface reasonably corresponded with calculation results.