Modeling and Experimental Study of a BiSbTeSe-Based Thermoelectric Module for Thermal Energy Recovery

Bi0.4Sb1.6Te2.7Se0.15S0.15 alloy thermoelectric material is introduced in this paper for thermoelectric power generation in the temperature range of 300–500 K. To evaluate the proposed material in a practical service environment, a BiSbTeSe-based thermoelectric module (TEM) with 254 thermoelectric elements is fabricated. Simulations and experiments are undertaken to assess the performance of the BiSbTeSe-based TEM under two different cases of constant heat source and heat flow. An analysis of heat transfer is conducted based on the temperature distribution of different cross-sections. Compared with a conventional Bi2Te3-based TEM, the proposed TEM can output a higher voltage when the temperature difference is higher than 60 K, especially in the heat flow case. When the temperature difference is 200 K, the open-circuit voltages are 10.90 V and 9.79 V, and the maximum output power is 8.8179 W and 7.1279 W under the constant temperature and heat flow cases, respectively. The maximum power is achieved when the load resistance is slightly higher than the internal resistance due to the effect of Peltier heat. The average deviation between the experimental values and simulation results is approximately 5.6%. The experiments verify the rationality and validity of the simulation model. This study reveals that the performance of the proposed BiSbTeSe-based alloy material is better than that of conventional bismuth telluride alloys within the range of 300–500 K. In addition, compared with constant heat thermal boundary conditions, it is more suitable for the heat flow case.