Calculators
Gas Turbine Heat Rate Correction
Corrects ISO-rated combustion turbine output and heat rate to site conditions per ISO 2314 and ISO 3977-2. Applies multiplicative correction factors for ambient temperature, barometric pressure, humidity, inlet filter loss, and exhaust back-pressure.
Method: Output and heat-rate correction factors are applied multiplicatively against ISO-rated performance: KT (ambient temperature), KP (barometric pressure), KIL (inlet loss), KEL (exhaust loss), KRH (humidity). Slopes are typical values for heavy-duty frame machines — substitute OEM curves when available. Temperature correction is piece-wise linear about 59 °F: above ISO output drops at −0.38 %/°F and heat rate rises at +0.12 %/°F; below ISO output rises at +0.24 %/°F and heat rate falls at −0.08 %/°F. Pressure: +1.0 %/% of 14.696 psia. Inlet loss: −0.38 %/inH&sub2;O output, +0.12 %/inH&sub2;O HR. Exhaust loss: −0.12 %/inH&sub2;O output, +0.04 %/inH&sub2;O HR. Accuracy ±2–3% within ±40 °F of ISO. Not valid for part-load, DLN firing-temp biasing, or evaporative/chiller inlet cooling. References: ISO 2314:2009 Gas turbines — Acceptance tests; ISO 3977-2; GPSA Engineering Data Book §15; GE Power GER-3567H.
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