Development of New and High Performance Combustor with Low CO_2 Emission

新型高性能低CO_2排放燃烧器的研制

基本信息

批准号：
10555063
负责人：
TAKITA Kenichi
金额：
$ 6.08万
依托单位：
Tohoku University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B).
财政年份：
1998
资助国家：
日本
起止时间：
1998 至 2000
项目状态：
已结题

项目摘要

Theoretical and experimental investigations were conducted for development of new and high performance combustor with low CO_2 emission. The effect of an addition of CO_2, which absorbed the emission of flame to the unburned gas, on flammability limit and burning velocity was mainly investigated as a model of lean burning technology by using the re-circulation of burnt gas. In the numerical analysis, the reabsorption of radiation emitted from a flame resulted in broader flammability limit and larger burning velocity than those of the adiabatic flame. The burning velocity of the mixture including 10% CO_2 became larger than that of the mixture with no CO_2. Moreover, it was revealed in the analysis that the effect of radiation reabsorption more strongly appeared under high pressure condition than atmospheric pressure because of decrease in the optical thickness at high pressure.Extinction limit of counterflow premixed flame with CO_2 addition was experimentally measured in a high pressure vessel to verify the above theoretical results. Stretch rates at extinction monotonically decreased with the pressure and the concentration of CO_2, and the ratio of decrease was almost same for any condition. Therefore, the effect of radiation reabsorption was small under conditions of the experiment(0.5MPa(pressure), 15mm(diameter of burner)). On the other hand, strong instability of the flame surface due to a hydrodynamic instability at high pressure appeared in the experiment. Therefore, a consideration to such instability is important for a design of combustor used under high pressure condition.

进行了理论和实验研究，以开发具有低CO_2发射的新型和高性能燃烧器。通过使用燃烧气体的重新传输，将添加CO_2的添加CO_2的影响主要研究为未燃烧气体和燃烧速度的易燃性限制和燃烧速度的影响。在数值分析中，与绝热火焰相比，从火焰中发出的辐射的重吸收导致更广泛的易燃性极限和更大的燃烧速度。包括10％CO_2的混合物的燃烧速度比没有CO_2的混合物大。此外，在分析中揭示了辐射重吸收的影响在高压条件下比大气压更强烈地出现在高压下的光学厚度下的降低。在高压上加入的逆流预混合火焰的伸展极限是在高压中添加的。压力容器以验证上述理论结果。随着压力和CO_2的浓度，灭绝时的拉伸速率单调降低，对于任何条件，降低的比率几乎相同。因此，在实验条件下（0.5MPa（压力），15mm（燃烧器的直径）），辐射重吸收的影响很小。另一方面，由于在实验中出现了由于高压下的流体动力不稳定而引起的火焰表面的强烈不稳定。因此，考虑这种不稳定性对于在高压条件下使用的燃烧器的设计很重要。