An investigation on thermoelectric coolers operated with continuous current pulses

• Periodical supercooling in TEC can be achieved in continuous pulse operation.
• A validated numerical model is used.
• The temperature increment is similar to a first-order step response.
• The maximum temperature drop in the different pulses is approximately identical.
• The temperature varying curve in the first pulse is decisive.

This paper studies the refrigeration characteristics of a thermoelectric cooler (TEC) operated under continuous current pulses. A validated numerical model is used to obtain the temperature curves versus time. Obtained results reveal that applying a next current pulse before the complete recovery of temperature overshoot would cause an lift of the temperature curve over the next pulse. However, the temperature increment varies very similar to that of the first-order step response. After a few of current pulses, the temperature shows a varying trend completely periodical. Furthermore, shorter current period results in greater temperature increment and slighter supercooling effect. The shortest current period to achieve a periodical supercooling effect is greatly subject to the temperature overshoot because the maximum temperature drop is approximately identical in each subsequent current periods. Moreover, although the initial temperature increases as the cooling load increases, the temperature varying characteristics are highly similar for the different cooling loads. This indicates that the temperature curve of the first pulse is decisive in a continuous operation. Results obtained here show that the periodical supercooling effect could be achieved if the current period is properly designed.