Electrocaloric refrigerator using electrohydrodynamic flows in dielectric fluids

Markus P. Hehlen; Alexander H. Mueller; Nina R. Weisse-Bernstein; Richard I. Epstein

doi:10.1117/12.2004009

11 March 2013 Electrocaloric refrigerator using electrohydrodynamic flows in dielectric fluids

Markus P. Hehlen, Alexander H. Mueller, Nina R. Weisse-Bernstein, Richard I. Epstein

Proceedings Volume 8638, Laser Refrigeration of Solids VI; 86380D (2013) https://doi.org/10.1117/12.2004009
Event: SPIE OPTO, 2013, San Francisco, California, United States

Abstract

Heat switches are a key enabling element of efficient refrigerators that are based on the electrocaloric effect. We demonstrate a new concept for a heat switch that is based on micro-scale electrohydrodynamic (EHD) flows in thin layers of dielectric fluids. In this device, convective flow of the fluid is controlled by applying an electric field across the fluid layer. This creates a heat switch that can be cycled between a “closed” state with efficient convective heat transport and an “open” state with less efficient conductive heat transport. Substantial switching of the thermal transport coefficient was achieved in 500 μm thick layers of commercial hydrofluoroethers and bias voltages of typically 390 V. The efficacy of the heat switch varied by almost four orders of magnitude for different biasing schemes. The highest efficacy was achieved by biasing a patterned strip electrode and using a planar ground electrode. A preliminary experiment found a thermal conductivity contrast of 4.7±1.1 for the switch in the closed vs. open state. We also characterize the electrocaloric response of commercial multilayer ceramic chip capacitors and show that they can serve as serve as a useful surrogate material for first-generation electrocaloric refrigerators until higher performing multilayer structures of ferroelectric polymers are available.

Citation Download Citation

Markus P. Hehlen, Alexander H. Mueller, Nina R. Weisse-Bernstein, and Richard I. Epstein "Electrocaloric refrigerator using electrohydrodynamic flows in dielectric fluids", Proc. SPIE 8638, Laser Refrigeration of Solids VI, 86380D (11 March 2013); https://doi.org/10.1117/12.2004009

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available