Thermal Insulation Performance of SiC-Doped Silica Aerogels under Large Temperature and Air Pressure Differences
Silica aerogel composite is an excellent thermal insulator for spacecraft under high-temperature and complex air environments. This study intends to evaluate SiC-doped silica aerogel’s thermal insulation performance under large temperature and air pressure differences. In this paper, the hot surface...
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MDPI AG
2022-05-01
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| Online Access: | https://www.mdpi.com/2310-2861/8/5/320 |
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| author | Sheng-Nan Zhang Hao-Qiang Pang Ting-Hui Fan Qing Ye Qi-Lin Cai Xi Wu |
| author_facet | Sheng-Nan Zhang Hao-Qiang Pang Ting-Hui Fan Qing Ye Qi-Lin Cai Xi Wu |
| author_sort | Sheng-Nan Zhang |
| collection | DOAJ |
| description | Silica aerogel composite is an excellent thermal insulator for spacecraft under high-temperature and complex air environments. This study intends to evaluate SiC-doped silica aerogel’s thermal insulation performance under large temperature and air pressure differences. In this paper, the hot surface’s temperature response of SiC-doped silica aerogel with different content was studied at significant temperature differences (Δ<i>T</i>) when pressure changes instantaneously. Their thermal insulation performance was evaluated by analyzing the influence of pressure gradients on the unsteady-state heat transfer. When the cold surface’s temperature of the specimen keeps constant at 15 °C and Δ<i>T</i> = 171~912 K, the results demonstrate that the correlative thermal conductivities of silica aerogel with 1% and 5.84% SiC are 0.02223~0.04077 W·m<sup>−1</sup>·K<sup>−1</sup> at <i>P</i> ≈ 10 Pa and 0.03165~0.04665 W·m<sup>−1</sup>·K<sup>−1</sup> at <i>P</i> = 1 atm, respectively. The aerogel composite with 0% SiC showed the best thermal insulation performance at Δ<i>T</i> < 200 K and <i>P</i> ≈ 10 Pa, while the aerogel with 5.84% SiC became the best at Δ<i>T</i> > 700 K and <i>P</i> = 1 atm. In addition, the transient pressure decreases will significantly impair the heat transfer of the gas inside the aerogel, thereby weakening the gaseous thermal conductivity and improving the thermal insulation performance. |
| first_indexed | 2024-03-10T03:50:24Z |
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| id | doaj.art-891464d24e1a467ea6733f8cfa8d129c |
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| issn | 2310-2861 |
| language | English |
| last_indexed | 2024-03-10T03:50:24Z |
| publishDate | 2022-05-01 |
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| series | Gels |
| spelling | doaj.art-891464d24e1a467ea6733f8cfa8d129c2023-11-23T11:08:12ZengMDPI AGGels2310-28612022-05-018532010.3390/gels8050320Thermal Insulation Performance of SiC-Doped Silica Aerogels under Large Temperature and Air Pressure DifferencesSheng-Nan Zhang0Hao-Qiang Pang1Ting-Hui Fan2Qing Ye3Qi-Lin Cai4Xi Wu5College of Energy, Soochow University, 333 East Ganjiang Road, Suzhou 215031, ChinaSchool of Materials Science and Engineering, Shanghai University, Shanghai 200444, ChinaCollege of Energy, Soochow University, 333 East Ganjiang Road, Suzhou 215031, ChinaCollege of Energy, Soochow University, 333 East Ganjiang Road, Suzhou 215031, ChinaCollege of Energy, Soochow University, 333 East Ganjiang Road, Suzhou 215031, ChinaCollege of Energy, Soochow University, 333 East Ganjiang Road, Suzhou 215031, ChinaSilica aerogel composite is an excellent thermal insulator for spacecraft under high-temperature and complex air environments. This study intends to evaluate SiC-doped silica aerogel’s thermal insulation performance under large temperature and air pressure differences. In this paper, the hot surface’s temperature response of SiC-doped silica aerogel with different content was studied at significant temperature differences (Δ<i>T</i>) when pressure changes instantaneously. Their thermal insulation performance was evaluated by analyzing the influence of pressure gradients on the unsteady-state heat transfer. When the cold surface’s temperature of the specimen keeps constant at 15 °C and Δ<i>T</i> = 171~912 K, the results demonstrate that the correlative thermal conductivities of silica aerogel with 1% and 5.84% SiC are 0.02223~0.04077 W·m<sup>−1</sup>·K<sup>−1</sup> at <i>P</i> ≈ 10 Pa and 0.03165~0.04665 W·m<sup>−1</sup>·K<sup>−1</sup> at <i>P</i> = 1 atm, respectively. The aerogel composite with 0% SiC showed the best thermal insulation performance at Δ<i>T</i> < 200 K and <i>P</i> ≈ 10 Pa, while the aerogel with 5.84% SiC became the best at Δ<i>T</i> > 700 K and <i>P</i> = 1 atm. In addition, the transient pressure decreases will significantly impair the heat transfer of the gas inside the aerogel, thereby weakening the gaseous thermal conductivity and improving the thermal insulation performance.https://www.mdpi.com/2310-2861/8/5/320SiC-doped silica aerogelthermal insulation performancetransient pressure changelarge temperature difference |
| spellingShingle | Sheng-Nan Zhang Hao-Qiang Pang Ting-Hui Fan Qing Ye Qi-Lin Cai Xi Wu Thermal Insulation Performance of SiC-Doped Silica Aerogels under Large Temperature and Air Pressure Differences Gels SiC-doped silica aerogel thermal insulation performance transient pressure change large temperature difference |
| title | Thermal Insulation Performance of SiC-Doped Silica Aerogels under Large Temperature and Air Pressure Differences |
| title_full | Thermal Insulation Performance of SiC-Doped Silica Aerogels under Large Temperature and Air Pressure Differences |
| title_fullStr | Thermal Insulation Performance of SiC-Doped Silica Aerogels under Large Temperature and Air Pressure Differences |
| title_full_unstemmed | Thermal Insulation Performance of SiC-Doped Silica Aerogels under Large Temperature and Air Pressure Differences |
| title_short | Thermal Insulation Performance of SiC-Doped Silica Aerogels under Large Temperature and Air Pressure Differences |
| title_sort | thermal insulation performance of sic doped silica aerogels under large temperature and air pressure differences |
| topic | SiC-doped silica aerogel thermal insulation performance transient pressure change large temperature difference |
| url | https://www.mdpi.com/2310-2861/8/5/320 |
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