• Anupam Kumari

The present work details thermodynamic and emission analysis of a Brayton-Brayton hybrid gas turbine cycle for Auxiliary Power Unit (APU) in aircraft applications. Energy, exergy and emission analysis of the proposed brayton -brayton cycle has been considered in order to establish its importance in futuristic auxiliary power units in aviation sector. The analyzed cycle comprises of two-gas turbine cycles back to back with one acting as the higher temperature topping cycle and the other utilizing the heat of the topping cycle and acting as the lower temperature bottoming cycle. Component level thermodynamic mathematical modeling of components of brayton-brayton cycle has been done. A code has been developed in C++ programming language which is based on the thermodynamic model of cycle components proposed. Results show that, the specific work initially increases with increase of pressure ratio (rp,c) at any turbine inlet temperature (TIT) but it starts decreasing at very high values of rp,c,. Gas turbine efficiency and specific work both increase for a fixed value of rp,c with the increase in TIT. The cycle is best suited for applications where power requirement ranges between 300-550 kJ/kg. The exergy analysis shows that maximum exergy loss of around 27% occurs during combustion in the cycle. The emission analysis shows that with increase in compressor pressure ratio NOX and primary-zone-temperature increase whereas CO and UHC emission decreases.

Brayton-brayton cycle; emission; equivalence ratio; exergy; exergy loss; hybrid cycle. Nomenclature

"ENERGY, EXERGY AND EMISSION ANALYSIS OF PROPOSED BRAYTON-BRAYTON HYBRID CYCLE FOR AUXILIARY POWER UNIT IN AIRCRAFT SYSTEM", International Journal of Emerging Technologies and Innovative Research (www.jetir.org), ISSN:2349-5162, Vol.9, Issue 9, page no.96-105, September-2022, Available :http://www.jetir.org/papers/JETIRFS06017.pdf

"ENERGY, EXERGY AND EMISSION ANALYSIS OF PROPOSED BRAYTON-BRAYTON HYBRID CYCLE FOR AUXILIARY POWER UNIT IN AIRCRAFT SYSTEM", International Journal of Emerging Technologies and Innovative Research (www.jetir.org | UGC and issn Approved), ISSN:2349-5162, Vol.9, Issue 9, page no. pp96-105, September-2022, Available at : http://www.jetir.org/papers/JETIRFS06017.pdf