Parametric optimization and exergy analysis of a high mach number aeroengine with an ammonia mass injection pre-compressor cooling cycle

Abstract

The Ammonia mass injection pre-compressor cooling (Ammonia MIPCC) cycle provides a substantial potential for the development of a high Mach aeroengine. To evaluate performance and analyze exergy of Ammonia MIPCC aeroengine, the parameter matching modeling method and Sequential Quadratic Programming (SQP) optimization are applied. These proposed methods can realize the constraints of compressor outlet temperature, combustor outlet temperature, power balance and flow conservation, thereby optimizing the specific impulse performance. Results show that the optimal operating line (OOL) of the Ammonia MIPCC aeroengine can be divided into two paths: the temperature limit operating line and the maximum specific impulse operating line. Moreover, the OOL of the Ammonia MIPCC aeroengine is always in a high exergy utilization state. When the ammonia rate increases from 0 to 0.08, the changes in exergy reduction rate, specific impulse and specific thrust corresponding to OOL at Ma 3.0 are 18.89%–31.83%, 2347.47 to 1113.56s, 768.91–953.47 N/(kg/s), respectively. Additionally, results show that the cycle with lower inflow cooling requirements can improve economy. In summary, parameter optimization and exergy analysis help to determine the working characteristics of high Mach number Ammonia MIPCC aeroengines, enhance the engine thrust performance and extend the operating envelope.