基于电热效应的带状制冷结构的模拟研究

Simulation Study of Belt Refrigeration Structure Based on Electrocaloric Effect

提出了一种基于电热效应的带状电热模块的模块化固体制冷装置。在该装置中,由电热材料P(VDF-TrFE-CFE)三元聚合物制成带状电热模块,在驱动轮带动下依次通过电极、热端蓄热器、冷端蓄热器实现电热效应的4个阶段,实现连续供冷。利用数值模拟对该结构的一个制冷单元进行了研究,研究了电热模块的极化时间、长度、运动速度、温度跨度以及所施加的电场强度的影响。研究结果表明:电热模块的极化时间对获得稳定的制冷功率密度(CPD)至关重要。CPD随着电热模块长度的增大而增大,随着其运动速度的增大而增大,随着两端温度跨度的增加而减小,并且与电场强度表现出很强的正相关性。另外,不同电场强度下存在最佳的COP/COPc值。在温度跨度为3 K、电场强度为160 MV/m的情况下,该制冷单元的CPD达到了6.61 W/cm^(2)。

Based on the electrocaloric effect, a novelty refrigeration device with a ribbon electrocaloric module made of electrocaloric material P(VDF-TrFE-CFE) ternary polymer was proposed. In the device, the ribbon electrocaloric module was driven by a driving wheel and moved sequentially pass through electrodes, hot end, and cold end. In this way, the EC module would undergo four stages of electrocaloric effect. Continuous cooling could be achieved at the cold end. A numerical simulation study of a cooling unit of the structure was carried out, and the effects of the polarization time, length, movement speed, temperature span and applied electric field strength of the electrocaloric module on the cooling performance were investigated. The results showed that the polarization time of the electrocaloric module was essential to obtain a stable cooling power density(CPD). The CPD increased with the increase of the length of the electrocaloric module and its motion speed, decreased with the increase of the temperature span at both ends. It also showed a strong positive correlation with the electric field strength. The optimal COP/COPc values existed for different electric field strengths. The cooling power density of a cooling unit reached 6.61 W/cm at a temperature span of 3 K and an electric field strength of 160 MV/m.