面向温差发电装置的相变散热器设计与测试

Design and Test of Phase Change Materials for Thermoelectric Power Generation Device

为构建环境监测自供电无线传感器网络,针对温差发电装置转换效率低、发电时间短等无法满足无线传感器的供电需求,本研究设计4种相变材料封装壳体作为温差发电装置的散热器,通过提供周期性热源,模拟自然环境,研究不同封装结构对发电特性及相变材料温度特性的影响。结果表明,相变散热器不仅可显著提升装置的平均电压,而且可有效延长发电时长。与风冷散热器相比,含有相变散热器的发电装置平均提升电压22%,最大输出电压可达1 V;温差平均提升42%,最大温差可达85℃;断开热源后,相变散热器作为热源反向供电,可在无光照或夜间持续供电,反向温差最大可达22℃,平均发电时长延长220%。此外,蜂窝状腔体结构的发电特性明显优于其他结构,腔体内部嵌入的微型平板热管可有效克服相变材料导热率低的缺点。壳体结构可大幅提升相变材料内部传热速率,含有相变散热器的温差发电装置可充分满足无线传感器网络持续供电的需求。

In order to build a self-powered wireless sensor network for environmental monitoring,aiming at the factors such as low conversion efficiency and short power generation time of thermoelectric power generation device cannot meet the power supply demand of wireless sensor,four kinds of phase change material cavities were designed as the radiator of thermoelectric power generation device.By providing periodic source and simulating natural environment,the effects of different packaging structures on the characteristics of power generation and the temperature characteristics of PCMs were studied.Results showed that the phase change radiator can not only significantly increase the average voltage of the device,but also effectively extend the generation time.Compared with air-cooled radiators,power generation device with phase change radiators increased the voltage by 22%on average,and the maximum output voltage can reach 1V;the temperature difference increased by 42%on average,and the maximum temperature difference can reach 85℃.After removing the external heat source,the phase change radiator served as a reverse power source,which can continuously supply power in the absence of light or at night.The maximum reverse temperature difference can reach 22℃,and the average power generation time was extended by 220%.In addition,the power generation characteristics of honeycomb cavity structure were obviously better than other structures,and the micro-channel heat pipe embedded in the cavity can effectively overcome the disadvantage of low thermal conductivity of phase change materials.The cavity can greatly improve the heat transfer rate inside the phase change material,and the thermoelectric device with phase change radiator can fully meet the demand of continuous power supply of wireless sensor network.