Study of pulsed thermoelectric cooler

• Main Author: Tan, Ho Chuan.
• Other Authors: Leong Kai Choong
• Format: Final Year Project
• Language: English
• Published: 2011
• Subjects: DRNTU::Science::Physics::Heat and thermodynamics
• Online Access: http://hdl.handle.net/10356/45672
• Institution: Nanyang Technological University

A thermoelectric cooler, made of bismuth telluride based elements, can achieve better cooling performances momentarily when rectangular pulse currents are introduced to the system. Pulse currents create instantaneous Peltier cooling that depresses the temperature of the cold side before Joule and Thomson effects, that need a finite time to reach the cold side, occur. In reference to established thermodynamic formulation using the Gibbs law and energy conservation methods, the entropy flux densities at regular intervals within the thermoelectric element were analysed and plotted against their respective temporal profile. Temperature-entropy (T-s) diagrams were able to show the amount of net cooling power of the various pulse inputs. In this project, a range of experimental sets of pulse and non-pulse currents were investigated. From the results, it has been observed that a pulse current of magnitude several folds greater than non-pulse currents was able to increase the cooling power of a thermoelectric cooler by as much as 15% during the pulse operation. By comparison of obtained experimental results, it was determined that an optimised pulse current of magnitude three folds above the non-pulse current produced the most efficient cooling effect, as any larger pulse current increased Joulean and Thomas heat that negated the cooling effect.