This paper enhances the thermal uniformity of the thermoelectric generator (TEG) system utilizing diesel engine exhaust gas by optimizing muffler inlet and outlet structures. Two series of computational fluid dynamic simulations at three engine operating modes were conducted to investigate the effects of their diameters and positions on the distribution of the hot-side heat exchanger (HSHE) temperature. The weighted average method was used to select the set of optimal parameters. The results indicate that these structural parameters affect the temperature uniformity on the HSHE base through impact on the exhaust velocity distribution inside the muffler. The optimal model with the inlet diameter of 35mm, outlet diameter of 40mm, and the inlet and outlet positions, respectively, 40mm and 34mm from the muffler centerline, achieves temperature differences across cross-sections of only 1.56K to 2.61K at an engine speed of 1920 rpm and torque of 31Nm. This finding enhanced temperature uniformity by 36.2% compared to the worst model in this study. The optimal muffler inlet and outlet structures obtained in this study offer the foundation to improve the longitudinal temperature uniformity of the TEG system, resulting in strengthening system performance and life span.

thermoelectric generator, thermal uniformity, muffler structure, performance.

Received: April 5, 2023; Accepted: May 8, 2023; Published: May 18, 2023

How to cite this article: Thong D. Hong, Minh Q. Pham, Hien M. Nguyen and Tri Q. Dinh, Optimizing diameters and positions of muffler inlets and outlets to enhance thermal uniformity of the diesel engine thermoelectric generator system, JP Journal of Heat and Mass Transfer 33 (2023), 119-134. http://dx.doi.org/10.17654/0973576323027

This Open Access Article is Licensed under Creative Commons Attribution 4.0 International License

References:

[1] D. Ji, H. Cai, Z. Ye, D. Luo, G. Wu and A. Romagnoli, Comparison between thermoelectric generator and organic Rankine cycle for low to medium temperature heat source: a techno-economic analysis, Sustain. Energy Technol. Assessments 55 (2023), 102914. doi:10.1016/j.seta.2022.102914.
[2] N. V. Burnete, F. Mariasiu, C. Depcik, I. Barabas and D. Moldovanu, Review of thermoelectric generation for internal combustion engine waste heat recovery, Prog. Energy Combust. Sci. 91 (2022), 101009. doi:10.1016/j.pecs.2022.101009.
[3] Z. Niu, H. Diao, S. Yu, K. Jiao, Q. Du and G. Shu, Investigation and design optimization of exhaust-based thermoelectric generator system for internal combustion engine, Energy Convers. Manag. 85 (2014), 85-101.
[4] C. Q. Su, C. Huang, Y. D. Deng, Y. P. Wang, P. Q. Chu and S. J. Zheng, Simulation and optimization of the heat exchanger for automotive exhaust-based thermoelectric generators, J. Electron. Mater. 45 (2016), 1464-1472.
[5] Y. Zhao, S. Wang, M. Ge, Z. Liang, Y. Liang and Y. Li, Performance investigation of an intermediate fluid thermoelectric generator for automobile exhaust waste heat recovery, Appl. Energy 239 (2019), 425-433.
[6] G. Shu, X. Ma, H. Tian, H. Yang, T. Chen and X. Li, Configuration optimization of the segmented modules in an exhaust-based thermoelectric generator for engine waste heat recovery, Energy 160 (2018), 612-624.
[7] T. D. Hong, Q. T. P. Nghiem, T. V. Mai and L. T. Le, A numerical simulation and experimental study on thermal uniformity of heat exchanger in motorcycle thermoelectric generator unit, JP J. Heat Mass Transfer 22 (2021), 89-105.
[8] T. D. Hong, M. Q. Pham, E. B. V. Huynh and T. Q. Dinh, The effects of muffler constructions on thermal uniformity and performance of the diesel engine thermoelectric generator system, JP J. Heat Mass Transfer 33 (2023), 71-82. http://dx.doi.org/10.17654/0973576323024.
[9] O. Bozorg-Haddad, B. Zolghadr-Asli and H. A. Loáiciga, A Handbook on Multi- Attribute Decision Making Methods, Wiley & Sons Publication, Inc., 2020.
[10] ANSYS Inc., ANSYS Fluent Theory Guide, Vol. 15317, Canonsburg, ANSYS Inc., 2013.