The book aims to provide a overview on how to improve the efficiency of shell and heat tube exchangers. The shell and tube heat exchanger was modeled (CATIA), meshed (hyper mesh) and simulated with CFD (ANSYS 15.0). The comparison has been made between the two types of flow breakers. The wave type of flow breakers gives the better result than the step strip flow breaker. Shell and tube heat exchanger is the most common type heat exchanger widely used in oil refinery and other large chemical process, because it suits high pressure application.