What condition might cause a high EGT in a gas turbine?

A high exhaust gas temperature (EGT) in a gas turbine can be influenced by various factors, and a dirty compressor blade is one of the more significant contributors. The compressor in a gas turbine is responsible for increasing the pressure and density of the incoming air before it enters the combustion chamber. When compressor blades are dirty, it hinders their ability to effectively compress the air, leading to reduced airflow into the combustion chamber. This insufficient airflow can result in a higher fuel-to-air ratio, causing incomplete combustion and thus elevated EGTs as the fuel does not burn efficiently.

The other conditions mentioned, although they can impact turbine performance, typically do not have as direct an effect on EGT. For instance, dirty fuel lines might lead to fuel starvation but wouldn't substantially elevate EGT on its own. Insufficient oil pressure primarily affects lubrication and can lead to mechanical failures rather than directly causing high EGT readings. A faulty ignition system could prevent the engine from starting or maintaining combustion but wouldn't generally be linked to elevated EGT under normal operating conditions.