Advanced exergy analysis of the turbojet engine main components considering mexogenous, endogenous, exegenous, avoidable and unavoidable exergy destructions

Hakan Caliskan ^a,*, Selcuk Ekici ^b, Yasin Sohret ^c

a. Department of Mechanical Engineering, Faculty of Engineering, Usak University, Usak, 64200, Turkey
         b. Department of Aviation, Igdir University, Igdir, 76000, Turkey
         c. Department of Airframe and Powerplant Maintenance, School of Civil Aviation, Suleyman Demirel University, Isparta, 32700, Turkey

Abstract: In this study, exergy dynamic and advanced exergy analyses are applied to the turbojet engine to assess its mexogenous, endogenous, exogenous, avoidable and unavoidable exergies under the environment conditions of 15 °C temperature and 1 bar pressure. The maximum exergy point in the turbojet engine is found for the combustor in which C11H23 (Jet-A1) fuel is combusted with air, while the minimum one is determined for the air compressor head where the free air enters. The combustion chamber has the maximum fuel, product and irreversibility rates and the air compressor has the minimum fuel and product exergy values, while the minimum irreversibility is found for the turbine. Maximum improvement potential rate is found for the combustion chamber (5141.27 kW), while minimum rate is determined for the turbine of the system (6.95 kW). Also, the turbine component has the highest exergy efficiency (97.20%) due to its expansion process, while combustion chamber component has the lowest exergy efficiency (55.39%) due to low efficient combustion process of the fuel. Furthermore, the mexogenous exergy destructions from maximum to minimum are found for the combustion chamber, air compressor and gas turbine units, respectively. Considering exergy dynamic analysis, the mexogenous exergy destruction rates of the combustion chamber, air compressor and gas turbine are found as 184.4 kW, 103.97 kW and 9.99 kW, respectively. Considering all results, the combustion chamber is the primer component to be handled for better efficiency and improvement.

Keywords: Advanced exergy; Efficiency; Gas turbine; Jet fuel; Mexogenous; Turbojet; Thermodynamic analysis; Aircraft

https://doi.org/10.1016/j.jppr.2022.07.002