多孔铂电极的蓄热传热性能及热稳定性研究

Research on Heat Storage and Heat Transfer Performance and Thermal Stability of Porous Pt Electrodes

摘要:

本文应用固体物理理论和方法，研究了氧传感器多孔铂电极材料的热容量、热导率等蓄热传热性能及热稳定性随温度、时间和晶粒半径的变化规律，探讨了原子非简谐振动对电极材料蓄热传热性能及热稳定性的影响。研究表明，多孔铂电极的热容量随温度的升高先增大后趋于常数，随晶粒半径和时间的增大而减小；多孔铂电极的蓄热稳定性系数随温度的升高先急剧增大后迅速减小，最后趋于常数，在温度约为60 K时，其蓄热稳定性最差。多孔铂电极的热导率随温度的升高先急剧减小后趋于常数，随晶粒半径的增大而增大，随时间的增长而减小；表面层对热导率的贡献随温度先急剧减小后趋于0；多孔铂电极的非简谐效应使其热容量有所减小，而使蓄热稳定性系数和热导率有所增大。本文所得结果与其它文献的结果基本一致，其结论可为固体电解质氧传感器的稳定性问题提供理论指导。

Abstract:

The variations of the heat storage and heat transfer properties such as heat capacity, thermal conductivity, and thermal stability of Platinum electrode for oxygen sensor with temperature, time and grain radius are studied by using the theory and method of solid-state physics, and the effect of anharmonic vibration of atoms on the heat storage and heat transfer properties and the thermal stability is discussed. The results show that the heat capacity of Pt electrode first increases with emperature, then tends to be constant, and decreases with grain radius and time. The thermal storage stability coefficient of the electrode material increases sharply at first and then decreases rapidly with temperature, and finally tends to be constant. When the temperature is about 60K, the thermal storage stability is the worst. The thermal conductivity of Pt electrode material decreases sharply at first and then tends to be constant with temperature, increases with grain radius, and decreases with time. The contribution of the surface layer to thermal conductivity decreases sharply at first and then tends to zero with temperature. The anharmonic effect of the electrode material reduces the heat capacity, while increases the thermal storage stability coefficient and thermal conductivity. The results obtained in this paper are basically consistent with that in other literatures, and the conclusions can provide theoretical guidance for the stability of solid electrolyte oxygen sensors.