Optimization of the Exhaust Mass Flow Rate and Coolant Temperature for Exhaust Gas Recirculation (EGR) Cooling Devices Used in Diesel Engines

An experimental investigation was conducted to characterize the operational transients of a small-scale 6-tube exhaust gas recirculation (EGR) cooling device, designed to simulate operating conditions of commercial devices, for a wide range of exhaust mass flow rates and different coolant temperatures. The transient pressure drop across the device and the thermal performance were measured for exhaust mass flow rates varying over a full range typically used in commercial devices. The coolant temperatures tested ranged from 25 °C to 55 °C. The temperature distribution on the outer shell surface of the small-scale EGR cooling device was also measured periodically using a thermal imaging camera to characterize the secondary side flow in the experiments. The results show that both the exhaust mass flow rate and the coolant temperature had a significant influence on the transient performance of the 6-tube EGR cooling device.