Which component primarily limits exhaust gas temperature (EGT) in a gas turbine engine?

• A. Combustion chamber
• B. Jet pipe
• C. Turbine
• D. Compressors

Answer: (C)

The turbine is the component that primarily limits exhaust gas temperature. After fuel combustion raises the gas temperature, this hot gas must pass through the turbine where it expands and does work to drive the compressor and accessories. The turbine blades and hot-gas path have a maximum temperature limit set by material strength and cooling capability. If the exhaust gas gets hotter than that limit, the turbine would overheat, leading to accelerated wear or failure. Therefore, the engine controls keep the fuel flow so the resulting exhaust temperature stays within the turbine’s thermal limits. The combustion chamber can set how hot the gas could potentially become, but the turbine’s temperature tolerance ultimately governs the actual limit. The jet pipe and compressors don’t impose this thermal constraint.