Optimization of pyroelectric conversion of thermal energy through the PZT ceramic buzzer and natural convection

Abstract

The main purpose of this work is to take advantage of the pyroelectric effect to produce electricity. We propose the use of the PZT ceramic buzzer, which possesses pyroelectric properties, to convert thermal energy into electrical energy by pyroelectric effect. We take advantage of natural convection to create temperature variation from a fixed thermal source. The amount of power harvested by this technique is sufficient to supply low-power systems. Our experiment consists in subjecting the PZT ceramic buzzer to a temperature variation insured only by natural convection created in an oil bath. In order to verify the existence of thermal fluctuations and confirm the efficiency of our technique, we use thermal imaging which shows that the temperature changes as a function of time. We propose in this paper an optimization of our energy-harvesting system by studying the effect of the convection system geometry on the pyroelectric response: the effect of volume on the pyroelectric response and the effect of the distance between the oil surface and the pyroelectric ceramic. It appears from our study that the harvested power increases when the distance between the buzzer and the fluid decreases but it increases slightly with the volume of liquid.