It is well known that a cycle performance can be improved considerably by adopting humid air to a simple gas turbine. Further improvement can be achieved by utilizing LNG (liquified natural gas) cold energy which is obtained during vaporization process of natural gas from liquid to gas state. Qualitatively well known fact of high specific power and improvement of efficiency are analyzed quantitatively for various cases. These include comparisons of power, efficiency and other important operating parameters for the cases of a simple cycle and HAT cycle with and without utilization of LNG cold energy. Compared with simple cycle, HAT cycle got 48% increase in total work, 16% increase in efficiency and HAT-LNG cycle got each 54%, 17% increases at 10 pressure ratio.
An analysis shows that a reasonable matching exists between the amount of LNG as fuel and the energy required to control inlet air temperature. It should be also admitted that use of a high cost liquified natural gas is inevitable for transportation of fuel from production site to consumer.