Thermodynamic and sustainability analysis of an organic rankine cycle system for turbofan engine
With the advancement of aviation industry, the use of energy has increased and its environmental consequences have become more significant. The energy efficiency of the aircraft has been the major interest to restrain the energy consumption increment. Since the energy prices are rising worldwide,...
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| Format: | Thesis |
| Language: | English |
| Published: |
2020
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| Subjects: | |
| Online Access: | http://psasir.upm.edu.my/id/eprint/104218/1/NUR%20ATHIRAH%20BINTI%20MOHD%20NASIR%20-%20IR.pdf |
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| Summary: | With the advancement of aviation industry, the use of energy has increased
and its environmental consequences have become more significant. The
energy efficiency of the aircraft has been the major interest to restrain the
energy consumption increment. Since the energy prices are rising worldwide,
the idea of increasing energy efficiency is a continuous challenge for the
industry. This is the reason why waste heat recovery (WHR) process is chosen
to improve the energy efficiency of aircraft engine. By reusing this waste heat
from the engine, the fuel consumption was reduced. Due to its unique features,
Organic Rankine Cycle (ORC) is a powerful potential for this purpose. This
thesis focused on the analysis of the Organic Rankine Cycle (ORC) from
thermodynamics and sustainability aspects. The performance analysis was
divided into two conditions of fluid which were subcritical and supercritical by
including preheater or superheater. The new ORC system was then integrated
to an aircraft turbofan engine. For a set of values of the initial parameters, the
thermodynamic cycle of the system was solved in the MATLAB software to
attain the net power output, thermal efficiency and the mass flow rate of
working fluid. The integration of ORC to a turbofan engine was performed and
the Thrust-Specific Fuel Consumption (TSFC) along with the fuel burn were
evaluated. From the results, it was noted that a better fuel consumption could
be accomplished by applying the ORC system to the turbofan engine with the
aid of superheater at both subcritical and supercritical conditions which were
noted as Case B and Case D. Taking into account the extra weight that can be
added to the engine, the fuel burn reduction were 7.68% for Case B and
10.74% for Case D. The exergetic sustainability index has emerged to be a
crucial method in determining the sustainability of a system. From this study,
the two best cases, Case B and Case D demonstrated exceptional
exergetic sustainability index at 0.474 and 0.470 respectively. The greater the
value of sustainability index, the better it is for the practical applications. Both of
the cases B and D showed a percentage improvement of 2.16% and 1.29%
respectively compared to the turbofan engine without ORC system. By analyzing the thermodynamic performance and sustainability index of the
system, this research indicated that ORC as waste heat recovery system is
compatible and beneficial to the turbofan engine, as it improves the engine’s
fuel consumption and overall performance. |
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