Energy efficient refrigeration - improvement of compact thermoelectric units through modeling, testing, and control

Abstract

Thermoelectric devices have been applied in compact refrigerators as an alternate to the traditional vapor compression systems. Drawbacks in cost and efficiency, as well as unknown reliability, however, have prevented wide spread use over vapor compression systems. Although thermoelectric devices eliminate both moving parts and circulating refrigerant, an energy efficient and reliable refrigerator is the goal. In this paper, the performance of compact thermoelectric and vapor compression refrigerators has been studied. A mathematical model was developed for the compact thermoelectric refrigerator and validated. A suite of tests were conducted to assess the performance of various control techniques. Through standard control operation, the thermoelectric unit reached a minimum temperature of 5.6°C in 74.4 minutes. With the implementation of pulse width and amplitude modulation control strategies, the thermoelectric unit's minimum temperature was decreased by 1.09°C and power consumption was reduced by 9.13%. The study establishes a basis to further investigate performance improvements for compact thermoelectric refrigerators.