In this paper,a new measurement technique for determining thermal conductivity of semitransparent media in the temperature range 300-800 K is reported.The experimental setup is based on the step power forced transient...In this paper,a new measurement technique for determining thermal conductivity of semitransparent media in the temperature range 300-800 K is reported.The experimental setup is based on the step power forced transient hot wire technique.It is assumed that the radiative contribution to the heat transfer process arises from emission,not from absorption.In this case,application of the'thermal quadruples'method allows a very simple construction of analytical models of the experimental setup.The parameter sensitivity analysis demonstrates that the thermal conductivity of semitransparent media can be determined from the hot wire temperature response. The experimental results of a kind of glass between 300 and 800 K are presented.展开更多
对固-气两相颗粒多孔材料导热系数的预测,尚未见以实验数据对其各预测模型进行分析及验证其准确度的相关文献。本文利用断电热线法测定石英砂、碳化硅、工程沙以及煤灰的导热系数;将模型预测结果与实验数据进行对比分析,结果表明,Kunii ...对固-气两相颗粒多孔材料导热系数的预测,尚未见以实验数据对其各预测模型进行分析及验证其准确度的相关文献。本文利用断电热线法测定石英砂、碳化硅、工程沙以及煤灰的导热系数;将模型预测结果与实验数据进行对比分析,结果表明,Kunii and Smith模型误差小;考虑孔隙率的影响,利用实测数据对Kunii and Smith模型进行修正,给出新的预测模型;通过与国外学者给出的实测导热系数的对比,验证了本文给出的修正模型的准确性。展开更多
The paper reports the measurements of the thermal conductivity of gaseous HFC32 over the temperature range 254.51K to 341.76K near the saturation line. The thermal conductivities were measured in a transient hot-wire ...The paper reports the measurements of the thermal conductivity of gaseous HFC32 over the temperature range 254.51K to 341.76K near the saturation line. The thermal conductivities were measured in a transient hot-wire instrument employing two anodized tantalum wires as the heat source with an uncertainty of 1%. The resuilts were correlated as a function of temperature for engineering use.展开更多
文摘In this paper,a new measurement technique for determining thermal conductivity of semitransparent media in the temperature range 300-800 K is reported.The experimental setup is based on the step power forced transient hot wire technique.It is assumed that the radiative contribution to the heat transfer process arises from emission,not from absorption.In this case,application of the'thermal quadruples'method allows a very simple construction of analytical models of the experimental setup.The parameter sensitivity analysis demonstrates that the thermal conductivity of semitransparent media can be determined from the hot wire temperature response. The experimental results of a kind of glass between 300 and 800 K are presented.
文摘对固-气两相颗粒多孔材料导热系数的预测,尚未见以实验数据对其各预测模型进行分析及验证其准确度的相关文献。本文利用断电热线法测定石英砂、碳化硅、工程沙以及煤灰的导热系数;将模型预测结果与实验数据进行对比分析,结果表明,Kunii and Smith模型误差小;考虑孔隙率的影响,利用实测数据对Kunii and Smith模型进行修正,给出新的预测模型;通过与国外学者给出的实测导热系数的对比,验证了本文给出的修正模型的准确性。
文摘The paper reports the measurements of the thermal conductivity of gaseous HFC32 over the temperature range 254.51K to 341.76K near the saturation line. The thermal conductivities were measured in a transient hot-wire instrument employing two anodized tantalum wires as the heat source with an uncertainty of 1%. The resuilts were correlated as a function of temperature for engineering use.
