Research Information System
Thesis Type: Postgraduate
Institution Of The Thesis: Gazi Üniversitesi, Fen Bilimleri Enstitüsü, Turkey
Approval Date: 2019
Thesis Language: Turkish
Student: ŞEYMA NUR EKMEKCİ
Supervisor: NUREDDİN DİNLER
Open Archive Collection: AVESIS Open Access Collection
Abstract:The most common technology that reduces the amount of NOx emitted by modern diesel engines is the Exhaust Gas Recirculation (EGR) system. The EGR cooler is an important component of the EGR system. EGR coolers are made up like the shell-tube heat exchangers with the hot exhaust gas being passed through the tubes and the coolant brought into and taken out of the shell chamber. Since the formation of NOx gases is accelerated at high temperatures, controlling the temperature also controls the formation of harmful NOx gases. The performance of the EGR cooler is largely dependent on the design, shape and size of the cooler tubes and diffuser. It is possible to increase the effectiveness of the EGR cooler by optimizing the size and shape of the tubes. In this study, flow and heat transfer properties of five models are investigated. The temperature, velocity and pressure regions of the fluids in three-dimensional EGR coolers are simulated. In the process of analysis, commercial ANSYS FLUENT software was used. While the EGR coolers were examined numerically, the inlet flow rate of the exhaust gas was changed. The effects of different EGR cooler designs and exhaust gas inlet flow rates on EGR performance are presented numerically. The highest cooler efficiency (77.8%) and the temperature drop (39.8%) were obtained when the inlet flow rate of the exhaust gas was the lowest (0.005 kg/s) in the Model 2 EGR cooler.