Abstract
To understand working features of a micro-tube combustor, combustion of CH4/O2 was carried out in a ceramic tube with an inner diameter of 1.4 mm and a stainless steel tube with an inner diameter of 2 mm respectively. In the tests, combustion characteristics and heat loss of micro-tubes were studied. It is shown that when the equivalent ratio (ER) was less than 1, CH4 was not completely oxidized and a lot of gas H2 and CO were then produced, which lowered the combustion heat release. If ER equaled 1, CH4 was completely oxidized to gas CO2 and water vapor, and the reaction released the maximum combustion heat. Meanwhile, heat loss of the tube wall reached the highest. Heat loss of the stainless steel tube accounted for 22% of the heat release at most. Since wall emissivity of the stainless steel tube was larger than that of the ceramic tube, the radiative heat loss of the former was very large, accounting for 70% of the total heat loss at most. Additionally, because thermal conductivity of ceramic was less than that of stainless steel, temperature gradient along axis of the former was larger than that of the stainless steel tube, which was disadvantageous to axis heat transfer and flame stabilization.
| Original language | English |
|---|---|
| Pages (from-to) | 199-204 |
| Number of pages | 6 |
| Journal | Ranshao Kexue Yu Jishu/Journal of Combustion Science and Technology |
| Volume | 14 |
| Issue number | 3 |
| Publication status | Published - 2008 |
| Externally published | Yes |
Keywords
- Combustion test
- Heat loss
- Methane
- Micro-combustor
- Oxygen