Abstract
Thermal conductivities of gas in free space and in nano-porous materials were theoretical investigated. The Hot Disk thermal constant analyzer based on the transient plane source method was adopted to measure the effective thermal conductivity of nano-porous materials within a gas pressure range from 0.01 Pa to 1 MPa. The influence of temperature and gas pressure on the effective thermal conductivity of nano-porous materials was investigated experimentally. The contribution of gas heat conduction to the effective thermal conductivity of nano-porous materials was decomposed from the experiment result. The effective thermal conductivity of nano-porous materials increases rapidly with the increases of gas pressure. The decomposed contribution of gas heat conduction is higher than the gas thermal conductivity in nano-porous materials and the difference increases with the increment of pressure and even higher than the gas thermal conductivity in free space at 1 MPa. The influence of temperature on the gas heat conduction becomes apparent at gas pressure higher than 400 kPa.
| Original language | English |
|---|---|
| Pages (from-to) | 756-759 |
| Number of pages | 4 |
| Journal | Kung Cheng Je Wu Li Hsueh Pao/Journal of Engineering Thermophysics |
| Volume | 34 |
| Issue number | 4 |
| Publication status | Published - Apr 2013 |
| Externally published | Yes |
Keywords
- Contribution of gas heat conduction
- Effective thermal conductivity
- Gas thermal conductivity
- Nano-porous materials