Research on discharge process of Bi2Te3 module under different thermal stimulation conditions

In the actual working process, the working environment temperature of the thermoelectric device is constantly changing, and rarely remains stable, a thermoelectric device is composed of more than one thermoelectric module monomer (PN junction), each of which can be used as an independent research object. To address this issue, the thermoelectric properties of thermoelectric modules (p, n-type Bi2Te3) are measured under different temperature environments. A self-constructed thermoelectric performance test platform, an infrared thermal imager, and a voltage acquisition system are used to monitor different temperature difference conditions in realtime. A transient discharge evaluation model was established to calculate the real-time discharge amplitude of the thermoelectric module based on its temperature gradient distribution. The results show that the error of the transient discharge evaluation model is about 5%, which is reliable. For large-sized thermoelectric modules, the maximum discharge amplitude under open circuit voltage can be obtained solely based on the overall temperature gradient of the thermoelectric module; the amplitude of the electrical output signals increases uniformly when the temperature difference between the two ends of the module is increasing uniformly; and the stable electrical output signals are also produced at both ends of the module when the temperature difference is stabilized. After stabilization, when the temperature drops uniformly, the amplitude of the electrical output signal decreases uniformly. In the range of T = 298-573 K, the greater the temperature difference between the two ends of the thermoelectric module is, the greater the amplitude of the stabilized electrical output signal is; and vice versa. The greater the rate of thermal loading, the faster the increase in the amplitude of the electrical output signal at both ends of the thermoelectric module. This also reduces the time needed to reach steady state equilibrium, enabling the thermoelectric module to produce a stable electrical output earlier than individual p and n-type Bi2Te3 modules.