水浸煤自然发火特性研究

    Study on spontaneous combustion characteristics of water-soaked coal

    • 摘要: 为了研究不同含水率的水浸煤对煤自然发火的影响程度,制备了不同含水率煤样,采用程序升温试验测试煤样的热重和CO产生率,同时使用SEM(扫描电子显微镜)观测不同含水率下的煤样表面形貌特征。结果表明:水分能够改变煤的热分解特性,当煤含水率为6%~14%时,煤自燃所需温度随含水率的增大而降低,缩减煤自燃的进程;当煤含水率为14%~36%时,煤自燃所需温度随含水率的增大而升高,延长煤自燃进程。研究还发现:水分能够影响煤的氧化特性,当含水率低于一定值时,增大煤的含水率能够促进CO的释放,有利于煤的自燃;当含水率高于一定值时,增大煤的含水率能够抑制CO的释放,阻碍煤的自燃,含水率约为14%的煤最易于自燃。同时,含水率对煤体孔隙发育也有双重作用,随着含水率的增加,煤体的孔隙和裂纹增多,但是,当含水率达到一定程度时,煤体的孔隙和裂纹被水分充填,抑制煤体的裂隙扩展和生成。

       

      Abstract: In order to investigate the influence degree of water-soaked coal with different moisture contents on coal spontaneous combustion, coal samples with different moisture contents are prepared, programmed temperature experiment was used to test the thermal weight and CO production rate of coal samples, and SEM (Scanning Electron Microscope) was used to observe the surface morphology characteristics of coal samples with different moisture contents. The results show that moisture can change the thermal decomposition characteristics of coal; when the moisture content of coal is 6%-14%, the temperature required for coal spontaneous combustion decreases with the increase of moisture content, which reduces the process of coal spontaneous combustion; when the moisture content of coal is 14%-36%, the temperature required for coal spontaneous combustion increases with the increase of moisture content, which prolongs the process of coal spontaneous combustion. The study also found that moisture can affect the oxidation characteristics of coal, when the moisture content is lower than a certain value, increasing the moisture content of coal can promote the release of CO and facilitate the spontaneous combustion of coal; when the moisture content is higher than a certain value, increasing the moisture content of coal can inhibit the release of CO and hinder the spontaneous combustion of coal; coal with a moisture content of about 14% is the most prone to spontaneous combustion. In addition, moisture content had a dual effect on the development of coal pores. With the increase of moisture content, the pores and cracks of coal increased, but when the moisture content reached a certain level, the pores and cracks of coal were filled with water, suppressing the expansion and generation of coal cracks.

       

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