Coupled effects of thermal contact pressure, thermal load, and heat flux distribution on the performance of thermoelectric generator

Thermoelectric generators (TEGs) have attracted sustained research attention in energy harvesting applications such as waste heat recovery, emergency power supplies, and remote sensing, owing to their unique all-solid-state energy conversion characteristics and exceptional operational reliability. Existing studies have individually investigated the critical effects of thermal contact pressure, thermal load, non-uniform heat flux distribution, and liquid cooling dynamics on TEG performance. However, a systematic understanding of their synergistic interactions is still lacking. This work presents a comprehensive experimental study elucidating the multiparameter coupling mechanism through meticulously designed thermal-electrical-structural characterization. Results found that a critical cold-state thermal contact pressure (∼1.2 MPa) is required during TEG assembly. This minimum pressure ensures that interfacial materials do not excessively mitigate TEM-induced thermal stresses at the hot and cold sides. In addition, maximum power output consistently occurs under decreasing heat flux distributions aligned with coolant flow direction, regardless of thermal load levels. The key novelty lies in the systematic, simultaneous quantification of these parameters and the discovery of their synergistic effect, leading to a 12.7% power increase compared to an unfastened TEG (0.61 MPa) with a concave heat flux distribution. This study provides a thermo-mechanical-electrical coupling optimization principle that promotes TEG performance across various heat source configurations. • Thermal-electrical-structural multiparameter coupling was studied. • Critical cold-state installation pressure during TEG assembly was identified. • Optimized hot-side heat flux distribution pattern was identified. • The synergistic optimization yields a power increase of 12.7%.