Typical Characteristics of Gas Turbine-Based CCHP System with Inlet Air Cooling

Abstract

Gas turbine-based CCHP system performance is strongly influenced by the ambient conditions. Gas turbine inlet air cooling technology improves gas turbine performance and its integrated CCHP system performance as well. Using the typical analytical characteristics of the system components, i.e. ， small-sized gas turbine, single pressure HRSG and double-effect water/LiBr absorption chiller, this paper investigated the effect of gas turbine inlet air cooling on the operation performance of an integrated CCHP system. Thermal efficiency, equivalent exergy efficiency and economic exergy efficiency of the system were also discussed. The results indicate that, every 1℃ increase in gas turbine inlet air temperature averagely results in 0.879% decrease in power capacity, 0.282% decrease in heat capacity and 0.205% decrease in cooling capacity. Gas turbine inlet air cooing influences the CCHP thermal efficiency and economic exergy efficiency slightly, even brings out a negative increase. Nomenclature: COP--performance coefficient of chiller COP/ COP 0 --relative performance coefficient G f --relative fuel consumption rate N gt --relative power output Q c --relative cooling capacity Q h --relative heating capacity H u --low calorific value of fuel(kJ/kg) R--load rate of chiller r--ratio of work to heat t a --ambient temperature (℃) t 1 --inlet air temperature (℃) t cs --chilled water temperature t wi --inlet cooling water temperature of chiller X Ac --flowrate ratio of the steam for the absorption chiller to the total HRSG steam η ec --economic exergy efficiency η ec /η ec0 --relative economic exergy efficiency η gt --gas turbine design efficiency π c --pressure ratio of gas turbine p s --steam pressure of HRSG α--price ratio of cooling to power β--price ratio of heating to power γ--ratio of steam flowrate to fuel flowrate τ--temperature ratio of gas turbine 0--design value