US 9,310,109 B2 · Electrocaloric effect heat transfer device dimensional stress control

Abstract

Technologies are generally described herein for electrocaloric effect heat transfer devices and methods effective to facilitate thermal energy transfer while mitigating mechanical stresses caused by expansion or contraction of electrocaloric effect material layers during thermal energy transfer operations. Some example heat transfer devices may include heat transfer stacks with at least two electrocaloric effect materials. Expanding electrocaloric effect material and contracting electrocaloric effect material are utilized to cancel the aggregate longitudinal dimensional change during application of an electric field. Some example heat transfer devices may utilize segmented electrocaloric effect material layers with stress relief gaps separating segments to mitigate delamination stress caused by lateral expansion or contraction of the electrocaloric effect material.

Claims25

Dependent claims

A method to transfer thermal energy from a heat source to a heat dump, the method comprising:

applying at least one electric field across a first electrocaloric effect material layer and across a second electrocaloric effect material layer of a heat transfer device in thermal contact with the heat source and the heat dump;
and
in response to the applied at least one electric field, transferring thermal energy between the first electrocaloric effect material layer and the second electrocaloric effect material layer in a direction from the heat source toward the heat dump while restricting thermal energy transfer in a direction from the heat dump toward the heat source and at least partially canceling a dimensional change of the first electrocaloric effect material layer due to expansion by a dimensional change of the second electrocaloric effect material layer due to contraction so as to maintain an approximate total length of the heat transfer device.

A method to transfer heat through a heat transfer device between a heat source and a heat dump, the method comprising:

applying a first electric field to a first electrocaloric effect material configured to expand and to change temperature of the first electrocaloric effect material in response to application of the first electric field;
applying a second electric field to a second electrocaloric effect material configured to contract and to change temperature of the second electrocaloric effect material in response to application of the second electric field, wherein a thermal rectifier material of the heat transfer device is in thermal contact with the first electrocaloric effect material and the second electrocaloric effect material;
transferring thermal energy, facilitated by the thermal rectifier material, between the first electrocaloric effect material and the second electrocaloric effect material in a direction from the heat source toward the heat dump while maintaining an approximate total length of the heat transfer device;
and
limiting transfer of the thermal energy, facilitated by the thermal rectifier material, between the second electrocaloric effect material and the first electrocaloric effect material.

2 more elements

A heat transfer system, comprising:

a heat source;
a heat dump;
a heat transfer device in thermal contact with the heat source and the heat dump, the heat transfer device comprising:
a first electrocaloric effect material layer;
a second electrocaloric effect material layer in thermal contact with the first electrocaloric effect material;
and
a plurality of electrodes positioned to apply at least one electric field across the first and second electrocaloric effect material layers to transfer thermal energy between the first and second electrocaloric effect material layers in a direction from the heat source toward the heat dump while thermal energy transfer in a direction from the heat dump toward the heat source is restricted, wherein a dimensional change of the first electrocaloric effect material layer due to expansion is at least partially cancelled by a dimensional change of the second electrocaloric effect material layer due to contraction so as to maintain an approximate total length of the heat transfer device.

4 more elements

Dependencies are inferred from the claim text.

Electrocaloric effect heat transfer device dimensional stress control

Life of this patent

Electrocaloric effect heat transfer device dimensional stress control

Life of this patent

Abstract

Claims25