Analysis and finding optimal values of a heat exchanger for using in diesel engine exhaust system

In the presented research, the analysis and finding optimal values of a heat exchanger used in the exhaust system of a diesel engine has been discussed. The main purpose of using this heat exchanger is to reduce the temperature of combustion products exhausting from the engine. This can be done by mounting a heat exchanger at the exhaust gas path. In order to analyze the issue, different designs of heat exchangers have been regarded. Three- and five-tube heat exchangers reduce the temperature of the smoke to an acceptable level by increasing the contact surface between the smoke and the cooling water. However, the pressure drop created on the side of the smoke is high in these designs. The use of annular fins and longitudinal fins on the smoke side also increase the heat transfer by increasing the contact surface between the smoke and water flow and the turbulence in the smoke path. However, in this design the heat exchanger outlet temperature is higher than allowed value (350 ). Furthermore, in this design, the pressure drop also increases. After the investigations carried out to reduce the temperature of the smoke, shell and tube heat exchangers have been chosen as the final designs. The shell and tube heat exchangers is capable to reduce the exhaust temperature to 309.42 .