Exergy recovery from the exhaust cooling in a DI diesel engine for BSFC reduction purposes

• The effect of exhaust cooling on exergy recovery is studied experimentally.
• Second law efficiency for double pipe heat exchanger is calculated.
• Results show that the exhaust cooling makes a useful recovered exergy.
• Exergy recovery makes bsfc reduction about 5–15% in different load and speeds.

In this experimental research, the exergy recovery from a DI Diesel engine is investigated where a turbocharged OM314 DIMLER diesel engine was tested at various engine speeds (1200, 1400, 1600, 1800 and 2000 rpm) and torques (20, 40, 60, 80 and 100 N m). For this aim, a double pipe heat exchanger with counter current flow is used in the exhaust of engine. As an important outcome, by increasing the load and engine speed, the recovered exergy increased. Furthermore, the reduction of brake specific fuel consumption (bsfc) due to the use of recovered exergy from exhaust has also been studied in the current study. The results show that by using recovered exergy, bsfc decreased approximately 10%.