Which temperature parameter is commonly used to set start/run limits in gas turbine operation?

• A. EGT
• B. ITT
• C. Ambient temperature
• D. Oil temperature

Answer: (B)

Starting and running limits are set using a parameter that directly mirrors the hottest part of the gas path during ignition and acceleration. Inter-turbine temperature (ITT) measures the temperature between the compressor and turbine in the hot section, so it tracks the actual thermal stress on blades and disks as fuel is added and the engine speeds up. Because ITT responds quickly to changes in operating conditions, it provides a reliable, timely limit to prevent overheating and thermal damage during start and ramp-up. Ambient temperature and oil temperature don’t reflect the hot-section thermal state during startup, and while exhaust gas temperature can be informative, it lags behind the core gas-path temperatures and is less effective for controlling the start/run ramp.