Potential of vapor chambers in boosting output performance of flat thermoelectric generators

Abstract

In conventional flat thermoelectric generators (FTEGs), the output power suffers from insufficient thermoelectric modules (TEMs) and a drop in exhaust temperature. To solve the above problems, this paper proposes three novel FTEG configurations integrating vapor chambers (VCs). Further, based on a multiphysics numerical model, this paper explores the application potential of VCs in the FTEG. Results suggest that: (1) VCs increase the number of TEMs carried by FTEGs and improve the temperature uniformity of TEMs, thus greatly increasing the output power of FTEGs; (2) The output of FTEGs with VCs rises with the increase of exhaust temperature T_ex and mass flow rate m_ex, while the back pressure loss also increases; (3) The increase in thermal conductivity of VCs λ_vc further enhances the output of FTEGs, and λ_vc = 4000 W⋅m⁻¹⋅K⁻¹ is suggested by leveling off the cost and performance improvement; (4) The 3-FTEG features the optimal performance among three configurations, and at T_ex = 800 K, m_ex = 70 g/s, and λ_vc = 4000 W⋅m⁻¹⋅K⁻¹, its output power and net power reach 505.77 W and 464.49 W, respectively, exhibiting the improvements of 65.20 % and 68.68 % compared to those of the FTEG without VCs. This work demonstrates the potential of VCs in improving the performance of FTEGs.