Waste Heat Recovery via Inverted Brayton Cycle Bottoming a Twin-Turbo Gasoline Engine

Abstract

<div class="section abstract"><div class="htmlview paragraph">Air pollution from internal combustion engines poses a significant apprehension for both global warming and public health on a worldwide scale. The adoption of hybridization and electrification within the vehicular fleet can help to tackle these challenges. This study evaluates a waste heat recovery system for electric power generation, based on the Inverted Brayton Cycle (IBC) coupled with a high-performance gasoline engine. The Mercedes-Benz CLS 350 CGI engine platform was modelled in AVL Boost software and validated against the reference published experimental data. The engine model was then modified to incorporate the IBC to study the performance of the proposed hybrid propulsion system. The IBC power output was calculated at a wide range of engine speed and load, and results showed that up to 18 kW of extra power output can be generated by the IBC system. Compared to the IC engine in isolation, by employing the IBC in hybrid series powertrain configuration, electrical power output increased by up to 20% at high speed and load. Moreover, IBC coupling in a parallel hybrid configuration decreased the main engine fuel consumption by 10-20% at high engine load.</div></div>