Numerical investigation of the use of thermoelectric generator before intercooler in turbocharged tractor

In this thesis, the effects of different heat sink designs placed on the cold surface of the modules on the performance of a thermoelectric generator (TEG) system positioned between the compressor and intercooler of a turbocharged tractor engine were numerically analyzed. Literature reviews show that the heat sinks used in TEG modules generally consist of plate-shaped fins. In this thesis, however, perforated and slotted fin geometries were used on the cold side of the TEG module, deviating from the plate type; thus, the aim was to increase heat transfer from the cold surface by changing the boundary layer behavior. As a result of this applied design approach, a significant improvement in the overall performance of the TEG system was achieved. When existing research is examined, it is seen that many studies focus on changes made in the dimensions of p- and n-type semiconductor elements to improve the performance of TEG modules. However, no study has been found that aims to increase heat transfer and therefore TEG performance by changing the plate fins in the heat sinks used in these modules. In this respect, this study makes significant contributions to the literature. This thesis examines plate-type finned (PF) designs, designs created by punching holes in plate fins (PF-CP, PF-FBCP), slotted fins (S0.5H3, S0.5H15, etc.), and open-cell aluminum foam heat sinks with different pore densities (10, 20, and 40 PPI). The effects of these different designs on voltage, current, electrical power, and thermal efficiency obtained from TEJ modules, as well as their effects on parameters such as pressure drop, fan power requirement, and air temperature entering the intercooler, are investigated numerically. In the numerical analyses performed for the S0.5H15 configuration, thermal efficiency was approximately 5% higher, output voltage approximately 3% higher, and total TEJ output power 6.2% higher compared to the plate-finned (PF) configuration. The pressure drop values obtained in heat sinks other than open-cell aluminum foam were almost at the same level. The use of different heat sinks in TEJ systems resulted in an approximately 3.4–3.5% reduction in the air temperature entering the intercooler compared to the non-TEJ system. This reduction demonstrates that TEJ application has a positive effect on engine efficiency.