# Simulink Model of a Thermoelectric Generator for Vehicle Waste Heat Recovery
## 6 Conclusions  
Considering the vast amounts of wasted thermal energy from internal combustion engines, the study of thermoelectric power generation is necessary as a possibility to increase overall energy efficiency. Thermoelectric devices are environmentally friendly and have numerous other advantages including the lack of moving parts, high reliability the direct conversion of thermal energy into electrical energy, as well as low maintenance requirements. However, the main disadvantage of such devices is their low efficiency owing to the small ZT values currently found in commercial devices. In the present study, two Simulink models are presented (see Appendix A for detailed Simulink blocks). The first model was created based on the work of [PERSON] et al. [20] to estimate thermoelectric parameters of a thermoelectric module. The validation showed that, even though the temperature dependency of the thermoelectric parameters was neglected, there is a relatively good agreement with experimental data. Furthermore, a TEG model was proposed and validated for power output estimations in the case of exhaust gas thermoelectric generators. Model validation was accomplished using the results of [PERSON] et al. [32]. For the validation, the cold side heat exchanger model was adapted to match the cooling method of the authors with reasonable agreement. The next step was to study the possibility of using air as the cooling fluid and to achieve the same cold side temperature, the flow velocity of the cold air was adjusted (an air velocity of 13.1 m/s showed a relatively good agreement). After determining that similar results can be obtained with air as the cooling fluid, a parametric study was performed to show the potential of such a system for ICE exhaust coupling. The test conditions (used as input data for the cold side heat exchanger) consid  
Figure 16: (**a**) Module power output, (**b**) junction temperature, (**c**) module current, and (**d**) module voltage with respect to the load resistance ratio for a velocity of 90 km/h at various temperatures (\(-\)5, 10, 20, and 30 \({}^{\circ}\)C). ered a vehicle (with a respectively large engine capacity) traveling at different speeds (50 80, 90, and 120 km/h) under dissimilar ambient air temperatures (\(-\)5, 10, 20, and 30 \({}^{\circ}\)C). The results showed that either a high air velocity or a low outside temperature leads to greater TEG power output. For the analyzed cases, the peak power output was 4.568 W for a temperature gradient of 108.3 K. It was also found that increasing the heat rejection on the cold side requires a simultaneous growth in heat input at the hot side to facilitate a favorable temperature gradient and, therefore, the power output of the TEG. Overall this demonstrates that it is feasible to install an air-cooled TEG on a heavy-duty vehicle running at constant speed. Conceptualization, N.V.B. ; methodology, N.V.B. ; software, N.V.B. and D.M. validation, F.M., C.D., and N.V.B. ; formal analysis, N.V.B. and F.M. ; investigation, N.V.B. ; resources N.V.B. ; data curation, N.V.B. and D.M. ; writing--original draft preparation, N.V.B. ; writing--review and editing, N.V.B., F.M., and C.D. ; visualization, N.V.B. ; supervision, F.M. ; project administration N.V.B. All authors have read and agreed to the published version of the manuscript. This research received no external funding. Not Applicable. This paper was supported by the Project POCU/380/6/13/123927 \"Entrepreneurial competences and excellence research in doctoral and postdoctoral programs-ANTREDOC\", project co-funded by the European Social Fund. The authors declare no conflict of interest. Appendix A Detailed Simulink blocks (Figures A1-A14). Please note that the values that can be seen in the figures were not necessarily used to validate the model. Also, the iterative temperature calculation loop is not included here. _Heat exchanger-hot side (similar for cold side)_Figure A2: Hot side heat exchanger block—inputs. Figure A3: Hot side heat exchanger block—HX heat transfer equations and outputs.