What is a power turbine in gas turbine systems?

A power turbine in gas turbine systems plays a crucial role in the overall operation by converting exhaust gas energy into mechanical power. This conversion process involves the use of high-temperature, high-velocity exhaust gases produced by the combustor. As these gases pass through the power turbine, they cause the turbine blades to rotate, which in turn generates mechanical energy. This mechanical power can either be used to drive the compressor or other machinery, or it can be harnessed to produce electrical energy depending on the system's design.

The other options do not accurately describe the function of a power turbine. For example, the component that increases airflow into the system refers more to a compressor rather than a power turbine, while generating electrical power is typically associated with a generator rather than the turbine itself. Cooling is also not within the primary function of a power turbine, as its main purpose is to convert energy rather than manage thermal aspects of the system. Thus, the identification of the power turbine as a device that converts exhaust gas energy into mechanical power is aligned with its critical function within gas turbine systems.