Demonstration of scientific and economic feasibility of a solid-state heat engine. Final report, November 7, 1977-September 30, 1982

Technical Report · Fri Jan 01 04:00:00 EST 1982

OSTI ID:6315435

Olsen, R B

The use of the pyroelectric effet as a means for direct conversion of heat to electrical enrgy has been studied. Initial work concentrated on the Drummond-Carnot approach; later work focused upon a regenerative electric Ericsson approach. Demonstrated output power was raised from a previous high of 30 microwatts to 1 milliwatt, then 40 milliwatt, and then finally to 1.6 Watt (33 Watt/per liter of active pyroelectric) in separate experiments. Previous experiments had conversion efficiencies of roughly 0.001% (calculated). The 1.6 Watt device had a measured efficiency of 0.5% which is approximately one-tenth of the thermodynamic ideal (Carnot) limit. The active material for these pyroelectric conversion experiments was ceramic lead zirconate modified with Sn/sup 4 +/ and Ti/sup 4 +/ Pb./sub 99/Nb./sub 02/ (Zr./sub 68/Sn./sub 25/Ti./sub 07/)./sub 98/O/sub 3/ (PZST). In addition to its use in pyroelectric conversion experiments, PZST was the subject of several basic physical studies. These studies included the electric field dependence of the electrocaloric, polarocaloric and pyroelectric effects. PZST was also studied to determine its output electrical energy density (10mJ/cm/sup 3/K) as a function of electric field limits, cycle temperature limits, and type of thermodynamic cycle. Furthermore, the effects of hysteretic loss (approx. 10%) were quantified. Regenerative heat flow within the pyroelectric converter was also studied both experimentally and numerically. A plastic pyroelectric material with the required thermodynamic properties for pyroelectric conversion was found. The material is a copolymer of vinylidene fluoride-trifluoroethylene and has a potential cycle energy density of 10 to 35 times greater than existing PZST ceramic. This increased energy density results from the much higher dielectric strength of the copolymer.

• Research Organization: Power Conversion Technology, Inc., San Diego, CA (USA)
• DOE Contract Number: AC03-78ER01736
• OSTI ID: 6315435
• Report Number(s): DOE/ER/01736-T3; ON: DE83009316
• Country of Publication: United States
• Language: English

Related Subjects

30 DIRECT ENERGY CONVERSION
300800* -- Direct Energy Conversion-- Miscellaneous Converters
36 MATERIALS SCIENCE
360104 -- Metals & Alloys-- Physical Properties
360404 -- Materials-- Polymers & Plastics-- Physical Properties-- (-1987)
CERAMICS
DESIGN
DIRECT ENERGY CONVERTERS
EFFICIENCY
HYSTERESIS
LEAD COMPOUNDS
MATERIALS
NIOBIUM COMPOUNDS
OXYGEN COMPOUNDS
PETROCHEMICALS
PETROLEUM PRODUCTS
PLASTICS
PYROELECTRIC EFFECT
RESEARCH PROGRAMS
STANNATES
SYNTHETIC MATERIALS
THERMODYNAMICS
TIN COMPOUNDS
TITANATES
TITANIUM COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
ZIRCONATES
ZIRCONIUM COMPOUNDS