High-pressure thermo-chemical recuperation – a way toward sustainable propulsion systems

摘要

To meet GHG emission targets and to decrease oil dependency, overall energy consumption of road vehicles must be substantially reduced. Various types of propulsion technologies are under consideration, like internal combustion engine (ICE), hybrid electric (HE), plug-in hybrid electric (PHE), range extended electric (REE), electric battery, fuel cell, etc. The article provides a comparison of various propulsion technologies and arrives to the conclusion that internal combustion engines (ICEs) will be a major propulsion option in the foreseen future with massive penetration of hybrid vehicles to global markets. Utilization of more energy-efficient ICEs together with low-carbon-intensity fuels is, therefore, of great importance on a way toward development of sustainable propulsion systems. About one-third of fuel energy introduced to ICE is wasted with engine exhaust gases. A promising way of engine’s waste heat recovery is by using the energy of the exhaust gases to sustain endothermic reactions of fuel reforming. This approach is called Thermo-Chemical Recuperation (TCR).We go beyond the previous studies in this field by applying direct injection of the reformate gas together with the high-pressure steam-reforming process. We aim at developing a high-pressure TCR-ICE set as a part of a series hybrid propulsion system, thus alleviating the acute problems of the reformer’s startup and transient behavior. The obtained experimental results showed that engine energy efficiency is improved by 18%-39% (higher values at lower loads) and pollutant emissions are reduced by 73-94%, 90-96%, 85-97%, 10-25% for NOx, CO, HC and CO2emissions, respectively, compared with gasoline in a wide power range, without any need in exhaust gas aftertreatment.