Abstract The work concerned the ignition characteristics and alkali metals (Na and K) release behavior during the combustion process of single coal particles with the additional different forms of K contents. The measurement was performed in O2/N2 and O2/CO2 atmospheres. The high-speed camera was used to investigate the influences from different forms of potassium (KCl and K2CO3) on the ignition characteristics, and the temporal release behaviors of alkali metals were obtained with the detection of atomic emission spectrum of alkali metals (Na and K). The sample with additive of KCl has the higher emission intensity and lower ignition delay than that the sample with additive of K2CO3. The substituting CO2 for N2 had more effect for KCl than for K2CO3 addition in the initial stage of volatile combustion, but it reversed as burning progressed. The comparison of the gas phase temperature during the ignition with the appearance moment of the K emission could be further illustrated that the main reason affecting the release of atomic alkali metals was the presence of different form of potassium, which affected the liberation and diffusion rate of the volatiles.

中文翻译：

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添加不同形态钾的单粒煤的着火特性及碱释放研究

摘要 研究了单粒煤在不同形式的钾含量下燃烧过程中的着火特性和碱金属（Na和K）释放行为。测量在 O2/N2 和 O2/CO2 气氛中进行。利用高速相机研究了不同形态的钾（KCl和K2CO3）对着火特性的影响，通过检测碱金属（Na和K）的原子发射光谱，获得了碱金属的时间释放行为。 ）。添加KCl的样品比添加K2CO3的样品具有更高的发射强度和更低的点火延迟。在挥发性燃烧的初始阶段，用 CO2 代替 N2 对 KCl 的影响比对 K2CO3 添加的影响更大，但随着燃烧的进行，这种影响会逆转。