Integrated evaluation of Inverted Brayton cycle recovery unit bottomed to a turbocharged diesel engine

摘要

Internal combustion engines evolution has recently gained additional push, in relation to their environmental impact on global warming and air quality deterioration mainly in high congested areas, like urban environments. Several innovative technologies have been introduced in the market and many others are under development in order to reduce CO2 emissions during homologation cycles, including real driving emission tests. Among them, great attention has been paid to the waste heat recovery, since it can assure a significant improvement on overall engine efficiency and, so, fuel saving and CO2 emission reduction. A novel opportunity can be represented by directly exploiting the residual pressure and temperature of the flue gases through an Inverted Brayton cycle (IBC), in which the gases are expanded at a pressure below the environmental one, cooled down and then recompressed to the environmental value.