沙砾油层的着火与燃烧特性

Characteristics of Ignition and Combustion of Grit Oil Layer

通过实验和有关分析研究了火烧油层采油技术中所涉及的多孔介质油层着火与燃烧特性.在进行火烧油层实验的基础上,测得了油层中7个测点的温度变化,利用红外CCD拍摄了4个顺序时刻的辐射图像.结果表明,散热条件及油层的透气性等条件影响了油层的着火和燃烧区域的走向,燃烧区域向保温条件好和透气条件好的方向移动,油层的着火特性与点火器的功率有直接的关系,提高燃烧器功率可以促进着火的成功率.对实验测得的燃烧温度做Hurst指数分析,得出油层燃烧的分数维近似为1,结果表明油层的燃烧不同于流化床燃烧等常规的火焰燃烧,燃烧的紊乱程度明显低于常规的燃烧,其热量传递方式主要以辐射和导热为主,对流作用很少,提高燃烧温度对燃烧的稳定和平稳推进影响很大.

The characteristics of ignition and combustion of lacunaris medium oil layer were investigated through experiments and relevant analysis and these characteristics were involved in the oil extraction technology with burning oil layer. Based on the experiments of burning oil layer, the curves of temperatures versus time of seven points in oil layer at three operating conditions were obtained respectively and the images of heat radiation at four different times were photographed by using infrared CCD sequentially. The experimental results indicate that the spreading direction of combustion region in oil layer is influenced by cooling condition and ventilating capability. The ignition characteristic of oil layer is related directly to the power of ignitor and increasing the power of ignitor can promote the success probability of ignition. The fractal dimension of the oil layer combustion is about one through the Hurst coefficient analyzing of combustion temperatures. The analysis results indicate that the combustion of lacunaris medium oil layer is different from the conventional combustion such as the combustion of fluid bed and its turbulent degree is power obviously. Consequently, the heat convection in this kind of combustion is infrequent and the combustion temperature greatly influences the stability of combustion and smooth of spreading.