Thermodynamic Analysis of Effects of the Inlet Air Cooling on Cycle Performance in Combined BraytonDiesel Cycle

Abstract

In the present study, the effects of inlet air cooling on compound cycle performance in adiesel gas turbine engine system where waste heat is used in the composite power systemin the sustainable energy system were investigated thermodynamically. The effects of theinlet air cooling the system that enhances power production and the resulting thermal efficiency values were analyzed based on various operational variables (gas turbine pressureratio, diesel engine compression ratio, gas turbine inlet and fresh air inlet temperatures,etc.). The energy losses in each system component were determined and the second lawefficiency of the system was determined based on the introduced operational parameters.The gas turbine unit in the model included a gas generator with two compressors and ahigh-pressure turbine, and a low-pressure power turbine running on a separate shaft. Thediesel engine and gas-generator exhaust gases were mixed and expanded in a low-pressureturbine, leading to the production of power with the waste energy. In the cycle, an intakeair cooler, an intercooler and a recuperative air pre-heater were used. In the intake air cooling cycle, the power increase was around 15% when the pressure rate of the low-pressurecompressor was 3.5. Natural gas was used as fuel in the thermodynamic model. The cycleirreversibilitywas used in the calculations based onthe thermodynamic concepts