Calculation of Airflow through the Air Cycle Technology’s Turboexpander and Its Effects on a Diesel Engine—Part I

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.