Study of the Influence of Heat Exchanger Body Design Parameters on the Performance of a Thermoelectric Generator for Automotive Internal Combustion Engine

Nikolay Anatolyevich Khripach¹, Boris Arkadyevich Papkin¹, Viktor Sergeevich Korotkov¹ and Dmitriy Vladimirovich Zaletov²

¹Federal State Educational Institution of Higher Professional Education “Moscow state university of Mechanical Engineering (MAMI)” 107023 Moscow, Bolshaya Semenovskaya str., 38 ²Mobil GazService Ltd, 603000, Nizhny Novgorod region, Nizhny Novgorod, Holodny side str. 10a

DOI : http://dx.doi.org/10.13005/bbra/2249

ABSTRACT: This article presents a study of the influence of design parameters, such as the thickness and width of thermal fins and inter-fin grooves, on the performance of a thermoelectric generator for an automotive internal combustion engine. The overall dimensions of a thermoelectric generator and, as a consequence, the size of the surface, which exchanges heat with the exhaust gases, are often subject to limitations because it has to fit inside the vehicle’s exhaust system. Changing the thermoelectric generator body design by adding fins that increase the heat exchange area can significantly increase the amount of the recuperated thermal energy. However, it inevitably increases the exhaust gas pressure drop in the thermoelectric generator, which is certainly a negative impact on the internal combustion engine as a whole. According to our research methodology the fin thickness ranged from 0.75 to 5.0 mm and the groove width from 1.0 to 8.0 mm. Consequently, we considered 48 variants of the thermoelectric generator heat exchanger in total. The obtained results show a high degree of non-uniformity of temperature distribution in the cross sections of the thermoelectric generator, which leads to uneven heating of the thermoelectric generator modules, reduced efficiency and overheating. This research enabled us to select a design of the fins, which allows to achieve the heat flow through the thermoelectric generator modules of 19kW with exhaust gas pressure drop of 2.5 kPa, while taking into account additional technical solutions. This research helps to improve the technical and economic parameters of a thermoelectric generator for an automotive internal combustion engine at the model design stage, which significantly accelerates the process of its development. Subsequent laboratory tests of the developed thermoelectric generator model enable us to refine the parameters of the mathematical model and significantly improve accuracy of the calculations.

KEYWORDS: Heat exchanger; Thermoelectric generator; Recuperation of heat energy; Direct conversion of heat into electricity

This work is licensed under a Creative Commons Attribution 4.0 International License.