相变储能温差电池的仿真研究

Simulation of a phase change heat storage thermoelectric generator

相变储能温差电池可以利用自然环境中昼夜交替产生的温度变化,将收集的热量建立温差并转换为电能输出。采用ANSYS软件建立了以水作为相变材料的相变储能温差电池样机的有限元模型。对温差电组件在热、电输出特性不变的前提下进行了等效变换。在模拟的昼夜温度变化条件下,得到了温差电组件内侧和外侧温度、电池输出电压、输出功率和累计输出能量随时间变化的计算结果,计算值与试验值基本符合。计算还给出了不同时刻电池的温度分布,反映出容器内壁延伸出的肋片对相变的强化作用,以及相变在温差电组件处的容器内壁附近首先发生,再逐步扩展到离容器内壁及肋片较远的区域。

Phase change heat storage thermoelectric generators can utilize temperature variations during day/night cycles in the ambient condition, and exploit harvested heat to create a temperature difference and convert to power. A finite element model of a prototype generator with water as phase change material was established using ANSYS. An equivalent transformation of thermoelectric modules was performed based on maintaining thermal and electrical output characteristics. The temperature at inner and outer surfaces of the thermoelectric module, the voltage, power and total output energy of the generator during a simulated day/night temperature variation were obtained. The results were compared with experiment and found to be similar. The calculated temperature distribution shows that phase change is enhanced by fins connected to the inner wall of the container, and it occurs in the vicinity of the wall near the thermoelectric modules first, and then expands to regions farther from the wall and fins.