What does an increase in turbine inlet air temperature do to turbine efficiency?

An increase in turbine inlet air temperature typically reduces the efficiency of a gas turbine. This effect arises from the thermodynamic principles governing turbine operation.

As the inlet air temperature rises, the density of the air decreases, which means that there is less mass flow through the turbine for a given volumetric flow rate. Lower mass flow reduces the energy available for conversion into mechanical energy, which negatively impacts efficiency.

Additionally, higher inlet temperatures lead to increased heat losses and can push the operating conditions closer to the limits of the material capabilities, which may require operational adjustments that can further detract from efficiency. Therefore, while higher temperature can improve the chemical reaction rates in combustion, it adversely affects the overall thermodynamic cycle of the turbine, resulting in a reduction in its efficiency.