Waste energy recovery analysis of a diesel engine exhaust system

Abstract

The problem of waste energy recuperation from the exhaust gas of diesel engines has been investigated for many years by the manufacturers of passenger vehicles, heavy-duty vehicles and non-road vehicles. Currently, the energy of the exhaust gas is manly used for driving turbochargers. However, only part of the energy contained in the exhaust gas is used for this process. The outstanding energy is wasted through a heat exchange from the exhaust gas through the exhaust pipe to ambient air. Many scientific research works are aimed at the recovery of energy through transferring it from the walls to heat exchangers. The objective of the authors was the analysis of the temperature distribution in a diesel engine exhaust system in the aspect of recuperation of energy lost through heat exchange. To complete the objective, temperature and gas flow measurements were performed on the exhaust system of a 1.3 dm3 diesel engine installed on a dynamic test stand. On the test stand a complete engine exhaust system was installed, identical to that used in a real vehicle. The tests were carried out in the NEDC homologation test that was reproduced on the dynamometer through ISAC 400 software made by AVL. For the measurements, the authors used thermoresistors and a mass flow meter for the exhaust gas mass flow measurement (part of the SEMTECH DS portable exhaust emissions analyzer).