Experimental and numerical analysis of flow and heat transfer characteristics of EGR cooler in diesel engine

In this study, the heat transfer characteristics of three types of EGR coolers, such as Shell and tube-type EGR cooler (6 mm), Shell and tube-type EGR cooler (8 mm), and stack type-EGR cooler, were numerically investigated. The accuracy of predictions was verified by experimental results. A maximum difference between the numerical result and the experimental result for heat transfer efficiency of 9.22% was obtained. The results showed that the heat transfer efficiency of stack type-EGR cooler is higher of 36.6% and 27.7% than Shell and tube-type EGR cooler (6 mm) and Shell and tube-type EGR cooler (8 mm) was higher respectively. The results showed by increasing the mass flow rate, the heat transfer efficiency in the stack type-EGR cooler almost remain constant. When the stack type-EGR cooler is used, the heat transfer coefficient and Nusselt number improve significantly compared to the Shell and tube-type EGR cooler (6 mm) and Shell and tube-type EGR cooler (8 mm).