Investigation of parameters affecting exergy and emission performance of basic and intercooled gas turbine cycles

Abstract

In this article an attempt has been made to analyze the affect of various cycle operating parameters, compressor-pressure-ratio, TRIT (turbine-rotor-inlet-temperature) combustor-primary-zone-temperature, equivalence-ratio, and residence-time on thermodynamic as well as emission performance of the BGT (basic-gas-turbine) and IcGT (intercooled-gas-turbine) cycles on a comparative basis. Thermodynamic assessment of the proposed cycles, shows that rational efficiency of the IcGT (intercooled-gas-turbine cycle) to be 8.39% higher than the BGT (basic-gas-turbine cycle). Overall exergy destruction within the cycles has been found to the 4.42% lower for IcGT cycle as compared to BGT cycle. It has also been observed that the IcGT cycle delivers higher gas turbine specific work and thermal efficiency in comparison to the BGT cycle for the same compressor-pressure-ratio and TRIT. Emission assessment shows that at fixed value of equivalence-ratio and residence-time, NOx emission is higher at higher values of compressor-pressure-ratio (rp,c) for both cycles. The mass of NOx and UHC (unburnt-hydrocarbon) emission increases with increase in equivalence-ratio, whereas CO (carbon-monoxide) emission decreases with increase in equivalence-ratio. Emission performance maps show lower quantum of NOx and CO emission for the IcGT cycle. UHC emission is higher in case of IcGT cycle due to lower combustor inlet air temperature. Overall, both thermodynamic and emission performance of IcGT cycle is superior.