Chemical Engineering
A. Kamani; I. Mirzaee; N. Pourmahmoud
Abstract
In this study, first-law, second-law, and exergo-economic investigations are accomplished to recover the waste heat of a two-shaft turbofan engine applying a supercritical carbon dioxide Brayton cycle. The efficacy of different operating parameters including the inlet temperature of the turbine, the ...
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In this study, first-law, second-law, and exergo-economic investigations are accomplished to recover the waste heat of a two-shaft turbofan engine applying a supercritical carbon dioxide Brayton cycle. The efficacy of different operating parameters including the inlet temperature of the turbine, the pressure ratio of the compressor, and Mach number on the performance of the proposed system in terms of energy and exergy performance, exergy destruction rate, and annual levelized cost of investment have been examined. The results indicate that the energy performance of the cycle is specified as 42.94%, the second-law performance of the cycle is calculated as 85.88% and the whole power generation amount of the system is achieved to be 9806 kW. Also, the results display that among the various components of the proposed system, the maximum amount of exergy destruction occurred in the low-pressure compressor, the fan, and the mixer. It is found that by increasing the inlet temperature of the high-pressure turbine, the first-law efficiency and the second-law efficiency of the proposed cycle decrease while the total cost rate and exergy destruction rate increase. Moreover, it is inferred that the thermodynamic efficiency of the system rises when the pressure ratio of the compressor and Mach number increase. The outcomes also demonstrate that concerning the capital costs and exergy destruction costs of components, the highest amount is obtained for high-pressure turbine and recuperator, which are 326.3 $/h and 358.4 $/h, respectively.
S. D. Farahani; M. Alibeigi; M. R. Sabzehali
Abstract
The turbofan engines are one of the constitutes significant components of the aero engines. In this study, the thermodynamic modeling of the TF30-P414 turbofan engine is developed and validated with reference values. The aims of this research are to determine the effect of the changes in the thrust, ...
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The turbofan engines are one of the constitutes significant components of the aero engines. In this study, the thermodynamic modeling of the TF30-P414 turbofan engine is developed and validated with reference values. The aims of this research are to determine the effect of the changes in the thrust, fuel mass flow rate, and thermal efficiency with changes of the flight-altitude (H) and the flight-Mach number (Ma). Then, the changing of the exergy efficiency and exergy destruction rate were investigated. The results show that between the different components of the engine in different flight circumstances, the highest exergy destruction occurred in the combustion chamber and the lowest exergy destruction occurred in the nozzle. Also, optimization with the objective function of finding optimum flight conditions to find the highest exergetic efficiency in the flight-Mach number of 1.2 to 2.2 and the flight altitude of 10,000 to 15,000 meters. The results of this optimization reported that the maximum exergetic efficiency happened to the conditions of H=11236 meters and Ma=1.944 with an amount of 32.64%.
