Parametric study of thermoelectric power generators under large temperature difference conditions

To help study the performance of thermoelectric power generators in conditions where there are large temperature differences between the hot-side heat exchanger and the cold-side heat exchanger, this paper presents a simplified numerical model that includes temperature-dependent properties of thermoelectric materials. Specifically, the temperature difference is added into the calculations of the current across thermoelectric legs. The results indicate that the simplified numerical model could reduce calculation time without reducing calculation accuracy. The variable physical properties of thermoelectric materials should be considered in the counter-flow arrangement at high temperature, but they can be neglected in the co-flow arrangement. The inlet temperature of hot fluid and the variable physical properties of thermoelectric materials have a coupling influence on the performance of thermoelectric power generation, which could change the variation trend of output power. The performance of thermoelectric power generation for the counter-flow arrangement is better than that for the co-flow arrangement, especially with high heat transfer coefficients and long channel lengths. When the the various physical properties of thermoelectric materials are considered, the maximum output power and efficiency occur at ratios of load resistance to internal resistance of about 1.5-1.8 for output power and 1.7-2 for efficiency.