Effect of temperature and gas flow on the efficiency of an air bottoming cycle

摘要

The objective of this research is to analyse the performance of an Air Bottoming Cycle (ABC) by considering the effect of temperature and gas flow. Based on the energetic analysis, a thermodynamic calculation has been performed to investigate improving the thermal efficiency of the ABC. In this research, we suggest that the cycle should be consisted of two sub-cycles: Braysson and Joule. The flue gas from the top cycle is used in braysson cycle turbine to generate the power and the rest of the energy of this flow is exchanged to the pressurized joule cycle air flow. The results indicate that the higher temperature of the braysson inlet turbine and lower braysson turbine outlet temperature will be resulted in higher thermal efficiency. Again, the higher thermal efficiency is related to perform the lower overall pressure ratios in joule cycle. By performing the calculation, the maximum thermal efficiency and also the optimal design point of this ABC have been found. The results of this ABC show an increasing in thermal efficiency and output net work (W); of course this will lead to have less Specific fuel consumption (SFC).