Design of a Fluid-Based Micro-Scale Electrocaloric Refrigeration System

Abstract

The electrocaloric effect (ECE) is a phenomenon in which reversible temperature and entropy changes of a material due to polarization appear under the application and removal of an electric field. Materials with a giant ECE have recently been reported, suggesting practical application in cooling devices. In this paper, a refrigeration system composed of silicon MEMS cooling elements is designed based on the ECE in a terpolymer. Finite element simulations are performed to explore the system performance. The effect of the form of the applied electric field is studied. The time lag between the electric field and the diaphragm motion is found to affect the cooling power significantly. A parametric study of the operating frequency is also conducted. The results indicate that when the system is operated at a temperature difference of 5 K, a cooling power density of 2 W/cm2 is achieved for one element.

Energy Savings Potential and RD&D Opportunities for Non-Vapor-Compression HVAC Technologies

“…These projected COPs are 16-53% higher than the overall system COP of baseline air conditioners at AHRI test conditions (source temperature of 105°F and sink temperature of 55°F, ; however, they do not take system losses into account and were projected for very small capacities under slightly different temperature conditions. Simulation models have projected COPs of 8.7 for electrocaloric cooling systems with temperature lifts of 9°F and COPs as high as 30 at temperature lifts of 27°F (Guo et al 2013, Ozbolt et al 2013; however researchers have yet to observe this performance in experimental results. We have not identified any estimates or measurements of the efficiency of a full-scale electrocaloric prototype.…”