Maximum cooling temperature and uniform efficiency criterion for inhomogeneous thermoelectric materials
نویسندگان
چکیده
The maximum cooling temperature of a uniform thermoelectric material is limited by its dimensionless figure of merit ZT. Inhomogeneous or graded thermoelectric materials are mainly studied when there is a large temperature gradient and the material composition is typically optimized for maximum local ZT. We show that this is not the correct optimization for maximizing the cooling temperature. We give the theoretical limit of maximum cooling temperature for an ideal inhomogeneous material. Surprisingly, the optimum Seebeck profile in the device has three sections with distinct characteristics. As a contrast to the local ZT optimization, the uniform efficiency criterion is proposed for the design of graded thermoelectric materials in cooling applications. This optimization is applied to the practical Bi2Te3 material which is common in thermoelectric applications. Temperature and electrical conductivity dependences of the material properties are taken into account. The graded material is numerically optimized and it achieves a 27% cooling enhancement compared to the best homogeneous material.
منابع مشابه
Pulsed cooling of inhomogeneous thermoelectric materials
Abstract It has been proven that the maximum cooling temperature of a thermoelectric material can be increased by using either pulsed operation or graded Seebeck profiles. In this paper, we show that the maximum cooling temperature can be further increased by the pulsed operation of optimal inhomogeneous thermoelectric materials. A random sampling method is used to obtain the optimal electrical...
متن کاملExact Solution of a Constrained Optimization Problem in Thermoelectric Cooling
We consider an optimization problem in thermoelectric cooling. The maximum achievable cooling temperature in thermoelectric cooling is, among other things, affected by the Seebeck coefficient profile of the inhomogeneous materials. Mathematically, the maximum cooling temperature is a non-linear functional of the Seebeck coefficient function. In this study, we solve this optimization problem exa...
متن کاملResponse to “ Comment on ‘ Effective thermal conductivity in thermoelectric materials ’ ”
Articles you may be interested in Comment on " Effective thermal conductivity in thermoelectric materials " [J. Response to " Comment on 'Optimization of power and efficiency of thermoelectric devices with asymmetric thermal contacts' " [J. Erratum: " High efficiency semimetal/semiconductor nanocomposite thermoelectric materials " [J. Response to " Comment on 'A new approach to optimum design i...
متن کاملTransient cooling of thermoelectric coolers and its applications for microdevices
If a current pulse with a magnitude several times higher than the steady state optimum current is applied to a thermoelectric cooler, an instantaneously lower temperature than that reachable at the steady state can be obtained. Most previous studies of this transient cooling effect focus on the minimum temperature achievable for free standing thermoelectric (TE) elements. In this work, we syste...
متن کاملCombustion - Thermoelectric Tube
In direct combustion-thermoelectric energy conversion, direct fuel injection and reciprocation of the air flowing in a solid matrix are combined with the solid-gas interfacial heat transfer and the solid conduction to allow for obtaining superadiabatic temperatures at the hot junctions. While the solid conductivity is necessary, the relatively large thermal conductivity of the available high-te...
متن کامل