Efficient Cooling System Using Electrocaloric Effect

Abstract

The electrocaloric effect in thin films of an electrocaloric material has the potential to be used for efficient cooling systems for high power electronic devices. We numerically calculated the effect of parameters in electrocaloric refrigeration with a thermal switch of fluid motion on the thermal performance. The system of changing air and water flow with the pulse generation of cold energy increased the heat transfer efficiency to 67% at a frequency of 5 Hz. The optimum time delay of water flow to increase the heat transfer efficiency was zero at low frequency and became half of the time period to change heat for a high frequency of 100 Hz. When the heat transfer efficiency was high, the final temperature change in water flow was not the maximum temperature change.

Fluidic and Mechanical Thermal Control Devices

“…Mechanically actuated fluidic thermal switches are used at around room temperature, [ 39,50,51 ] with the exception of some gas‐gap applications at cryogenic temperatures, [ 41,45 ] for electronics cooling, [ 38,42,43 ] insulating materials, [ 48 ] outer space applications, [ 41,47,49 ] and caloric refrigeration. [ 52,53 ] To better discuss such thermal switches, the gas‐gap type is evaluated separately at the end of this section.…”

“…Mechanically actuated macroscopic thermal switches require an external force or pressure to control the motion of one (or several) solid parts. Intermittent contact can be achieved by different means, such as external stepper motors, [ 195 ] piezo‐stack actuators, [ 14,196,197 ] linear actuators, [ 15,198,199 ] solenoid actuators, [ 200 ] motorized z‐stages, [ 201 ] linear direct drive motors, [ 202 ] high‐power motors, [ 203 ] spindle‐drive motors, [ 204,205 ] pressure change, [ 52,206,207 ] or even manually. [ 208,209 ] Pressure change [ 206,207 ] and manual operation [ 208,209 ] have been used in cryogenics, and motors and actuators have been used at around room temperature.…”

3D‐FEM Simulation of a MEMS‐Based Electrocaloric Ba(Zr0.2Ti0.8)O3 Thin‐Film Microfluidic Refrigeration Device

“…They calculated a refrigeration capacity of more than 4.5 W cm −2 at a temperature span of 5 K and 20 Hz. Hirasawa et al . used a pulsatile flow of water and air as a fluid‐based thermal switch and numerically calculate the thermal behavior of their system at a given frequency and heat flow.…”

“…Hirasawae tal. [9] used apulsatile flow of water and air as af luid-based thermal switch and numerically calculate the thermal behavior of their system at ag iven frequencya nd heat flow.F eng and co-workers [10] investigated at hermoelectric EC-thermoelectric sandwich structure as am odel for a solid-state refrigeration device.T hey chose Ba(Zr 0.2 Ti 0.8 )O 3 (BZT-20) as the EC material and calculated ar efrigeration capacity of up to 8Wcm À2 at DT Span = 9K,w here DT Span is the temperature span between the hot and cold reservoirs.…”

Compact Thermal Management Device Using Electrocaloric Effect

“…In common American families, more than 30% of the power usage is spent on space cooling and refrigeration [1]. If we assume there to be a 10% increase of efficiency in the performance of thermal management applications, 110 terawatt hours of energy would be saved in America in 1 year.…”