Irreversibility of thermoelectric cooling model: Newtonian linear heat transfer and finite time thermodynamics.

The irreversibility of the thermoelectric cooling (TEC) model could analyze and optimize refrigeration performance. In present work, a one-dimensional thermal conductivity model of the internal irreversible thermoelectric element was first established. Subsequently, two categories of evaluation indexes were further analyzed, i.e., cooling capacity Qc and coefficient of performance (COP). The thermodynamic model of TEC was then established jointly with finite time thermodynamics. The influences of current and the ratio of heat transfer areas between cold and hot sides on the steady-state characteristics of TEC were further discussed under Newtonian linear heat transfer. In addition, a transient thermodynamic model of TEC equipment was built to compare the effects of pulse width, pulse gradient, and pulse current on the cold side temperature of the TEC module. Theoretical results demonstrated that the effective working range of the steady-state operating current is 2A ≤ I ≤ 25A, and the area ratio of heat transfer between cold and hot sides is 0.07 ≤ x ≤ 1. The cooling capacity (Qc) and coefficient of performance (COP) could reach up to about 50W and 2.0, respectively. In addition, the increase of external heat transfer capacity of the hot side could reduce the transient supercooling temperature and the peak overshoot temperature, simultaneously. Afterward, the cooling capacity was remarkably enhanced. Current research could provide a reliable support for the optimization design and performance improvement of the thermoelectric cooler. Thermal conductivity model of internal irreversible thermoelectric element was established; Effects of cold and hot ends on the TEC were discussed under Newtonian linear heat transfer; Effects of pulse width, gradient and current on TEC cold end temperature were investigated; Heat transfer capacity of TEC hot end could reduce supercooling and overshoot temperatures; The irreversibility of TEC model will enhance its potentials for low grade energy exploitation. [ABSTRACT FROM AUTHOR]