Study On Measurement Of Thermal Conductivity By TPS Method

As one of important thermal properties,the thermal conductivity directly reflects the heat transter capability of materials.It is need to be known in many occasions.Therefore,the measurement of the thermal conductivity of materials has extremely important significance for the application of materials.The transient plane heat source method(TPS)not only has the advantages of short measurement time,high accuracy,and wide range,but also has a good adaptability to the sample,and is suitable for measuring the thermal conductivity of almost all kinds of materials,including powders,solids,and liquid media.Therefore,it has attracted more and more researchers ’attention.Hot-Disk Method,as an important branch of TPS technology,has been widely used in the measurement of thermal conductivity of various materials.However,thermal properties of materials will varies with the type of substance and the environmental conditions in which they live,so it is necessary to study the changing mechanism of the thermal properties of materials in different circumstances.In this paper,the development of the measurement technology for thermal conductivity was introduced.Based on TPS method,a liquid thermal conductivity measurement device that can provide a stable temperature environment was developed,and pure water and ethanol were selected as the standard substance to complete the verification experiment.The experimental results showed that the measurement deviation of the thermal conductivity of pure water and ethanol is within 3%,which fully meets the test requirements of liquid thermal conductivity measurement.Finally,a device for measuring the thermal conductivity of solid mamterials at different temperatures and pressures was presented.The thermal conductivity of foam brick was measured under different temperature and pressure conditions.The results showed that pressure change has a significant effect on the thermal conductivity of foam bricks.At pressures below 500 Pa,the thermal conductivity increaseed at a larger rate as pressure increased,and the growth rate of its thermal conductivity value slowed down significantly at pressures above 1000 Pa.At different pressures,the thermal conductivity of the foam brick changed in the same trend when its temperature changed.