Thermal analysis of baffled shell and tube type EGR cooler for different types of tubes using CFD

Exhaust Gas Recirculation (EGR) technique using EGR cooler reduces the NOx content from the tailpipe emission of Diesel engines. Commercial computational fluid dynamics (CFD) code is used to solve and simulate the flow-fields and temperature distribution of fluids inside the EGR cooler. In this investigation two models (model-a and model-b) of EGR coolers are developed using Pro/Engineer Wildfire 4.0 software. Model-a is a single pass baffled shell and tube heat exchanger with staggered tube arrangement of plain tubes and having conical shaped stationary heads (gas inlet/outlet chamber) [2]. Model-b is having the same tube arrangement and spacing as they were in model-a, but the plain tubes were replaced with internally finned tubes to increase the internal surface area of tubes. The finned tubes are of same outer diameter and same tube material as that of plain tubes. In model-a and model-b, the inlet conditions of both the cooling water and hot gases are the same. These models are analysed with Ansys Fluent 13.0 software. The CFD results show that, by replacing the plain tubes with internally finned tubes, the rate of heat exchange between the cooling water and hot gases enhanced.