光学交流量热法同时测量低热导材料的热导率和比热容
An Optical-Based AC Calorimetry Method to Simultaneously Measure the Thermal Conductivity and Heat Capacity of Poor Thermal Conductors
宋尚智 1张可欣 1杨荣贵 1江普庆1
作者信息
- 1. 华中科技大学能源与动力工程学院,武汉 430074
- 折叠
摘要
传统的交流量热法采用一束经调制的激光周期性加热悬空的薄膜样品,通过热电偶测量样品表面距离加热点不同位置处的交流温升信号,由其幅值随距离的衰减(幅值法)或者相位随距离的滞后(相位法)来提取薄膜样品的面内热扩散率.本文提出新的基于光学的交流量热法可用于同时测定低导热块体材料的热导率及比热容.该方法的可行性通过测量无定形二氧化硅材料的热导率和比热容得到了验证,同时分析了测量误差,还讨论了实验测量应当使用的最佳光斑尺寸和调制频率的选择方法.
Abstract
Conventional AC calorimetry method uses a modulated laser to periodically heat up a suspended thin-film sample and a thermocouple to measure the thermal wave signals at different locations from the heating spot.The in-plane thermal diffusivity of the sample can be extracted from the amplitude attenuation(amplitude approach)or the phase lag(phase approach)as a function of distance between the heating and detecting spots.This paper proposes a novel optical-based AC calorimetry method to simultaneously measure the thermal conductivity and heat capacity of lowly conductive materials.This method is demonstrated and validated through the measurements of an amorphous silica sample.This paper also conducts uncertainty analysis and discusses the selection of the optimal spot size and modulation frequency used for the measurement.
关键词
光学交流量热法/热导率/比热容/低热导材料/热反射Key words
optical-based ac calorimetry/thermal conductivity/specific heat capacity/thermal insulator/thermoreflectance引用本文复制引用
基金项目
国家自然科学基金重点项目(52036002)
出版年
2024
NETL
NSTL
万方数据