Amidst escalating climate change, the sustainability of internal combustion
engine (ICE) vehicles, particularly in heavy transport, remains a critical
challenge. Despite emission reductions from 1990 to 2020, ICEs, particularly
diesel engines in Europe, continue to pose environmental challenges, notably in
nitrogen oxide (NOx) emissions. This study proposes a novel solution to address
the problem of NOx emissions by incorporating Air Cycle Technology’s (ACT)
turboexpander into diesel engines. Acting as a second-stage compressor,
intercooler, and expander, the turboexpander aims to lower intake air
temperature, thereby mitigating NOx formation. The study utilizes a 4.4-l
JCB-TCA-74 turbocharged diesel engine retrofitted with the ACT turboexpander as
the experimental platform. The methodology involves using empirical formulae to
calculate the key parameters of engine airflow for a standard turbocharged
diesel engine followed by repeating the calculations for the same engine fitted
with a turboexpander. Parameters including intake temperature, cylinder
temperature, exhaust gas temperature, and NOx emissions are analyzed in depth
and compared for both the engines. Initial calculations suggest that the
turboexpander has the potential to reduce intake temperatures by up to 34°C,
resulting in significant reductions in NOx emissions. These findings underscore
the promising role of turboexpanders in enhancing the sustainability of diesel
engines, urging further exploration across various engine types. As emissions
standards tighten, the adoption of innovative solutions like turboexpanders
could contribute to a cleaner and more sustainable future for the ICE.