Experimental study on applying the pyroelectric effect to low-grade waste-heat power recovery

The pyroelectric conversion cycle of heat to electricity is conducted adopting a single copolymer P(VDF-TrFE) (60/40) film of 40 μm thickness for low-grade waste-heat power recovery. Experimental results show that the continuous pyroelectric conversion cycle can be directly realized under the proper conditions without the loss of spontaneous polarization. The external voltage strongly affects the pyroelectric current and electrical energy output. Within the same temperature range and at the same changing rate, the pyroelectric current is enhanced with increasing external voltages. Heightening lower voltage and the difference between upper voltage and lower voltage facilitates electrical energy output. The net output energy density of pyroelectric conversion cycle reaches 40 mJ/cm³ under the condition of the temperature 40-70°C, upper voltage 900 V (electric field intensity approaches to 225 kV/cm). This heat-to-electricity conversion can be applied to low-grade waste-heat power recovery.