In the present study, emission indices for NO, NO₂, HONO, HCHO, CO, particle mass, and particle numbers including particle size distributions for three different offering candles were determined. The candles investigated showed similar emission characteristics with emission indices (g/kg) in good agreement with former candle emission studies. An average HONO/NO_x emission ratio of 6.6 ± 1.1% was obtained, which is much higher compared to most other combustion sources, indicating that candles may be a significant indoor source of this important trace gas. The particle size distributions indicate that the majority of the emitted particles are in the size range 7 ‐ 15 nm. Three modes were observed during burning the candles with very different emission profiles: a “normal burning” mode characterized by low particle number emission rates and small particles; an initial “sooting” behavior after ignition, and a final “smoldering” phase upon candle extinction with higher particle number emission rates and larger particles. The particle emission upon extinction is dependent on the extinction method. The NO_x emission indices were applied in a simple box model to calculate typical indoor NO_x concentration levels from candle emissions, which were in excellent agreement with direct measurements in a typical indoor environment.

中文翻译：

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确定 NO、NO2、HONO、HCHO、CO 和蜡烛发出的颗粒的排放指数。

在本研究中，确定了 NO、NO ₂、HONO、HCHO、CO、粒子质量和粒子数的排放指数，包括三种不同蜡烛的粒度分布。所研究的蜡烛显示出类似的排放特性，排放指数 (g/kg) 与之前的蜡烛排放研究非常吻合。平均 HONO/NO _x获得了 6.6 ± 1.1% 的排放率，与大多数其他燃烧源相比要高得多，这表明蜡烛可能是这种重要微量气体的重要室内来源。粒径分布表明，大部分发射粒子的粒径范围为 7 - 15 nm。在燃烧蜡烛过程中观察到三种模式，具有非常不同的排放特征：“正常燃烧”模式，其特征是低粒子数发射率和小粒子；点燃后的初始“烟尘”行为，以及蜡烛熄灭后的最终“阴燃”阶段，具有更高的粒子数发射率和更大的粒子。消光时的粒子发射取决于消光方法。该NO _X排放指数被应用在一个简单的盒子模型中，以计算来自蜡烛排放的典型室内 NO _x浓度水平，这与典型室内环境中的直接测量非常吻合。