Ammonia is regarded as a potential carbon-free alternative fuel. To have a better understanding of its combustion characteristics, development of feasible techniques for ammonia detection in combustion environments is essential. In the present work, planar laser-induced photofragmentation fluorescence (LIPF) was developed for quantitative measurements of ammonia in hot gas flows. A 193 nm ArF excimer laser was used to photo-dissociate ammonia. As a fragment, NH* radicals were generated, and the fluorescence at 336 nm was used for ammonia detection. Quantitative calibration of the LIPF signal was performed in hot flows either from laminar flames or an electric heating-pipe with a known amount of ammonia and temperature. Ultraviolet absorption was used to obtain accurate concentrations of ammonia in the hot flows from laminar flames. The single-shot detection limit of the LIPF technique was estimated to be ∼50 ppm and ∼130 ppm in hot flue gas at 1140 and 1750 K, respectively, and ∼0.2 ppm in a room-temperature nitrogen flow. The technique was applied to detect the slip of ammonia in a premixed laminar ammonia-air flame with a fuel-air equivalence ratio of 1.2. Over 5000 ppm unburned ammonia was detected in the post-flame region and measurements showed good agreement with predictions of a chemical model.

氨被认为是一种潜在的无碳替代燃料。为了更好地了解其燃烧特性，开发用于燃烧环境中氨检测的可行技术至关重要。在目前的工作中，平面激光诱导光碎荧光 (LIPF) 被开发用于热气流中氨的定量测量。193 nm ArF 准分子激光器用于光解氨。作为片段，NH* 自由基产生，336 nm 处的荧光用于氨检测。LIPF 信号的定量校准是在来自层流火焰或具有已知氨和温度的电加热管的热流中进行的。紫外吸收用于获得来自层流火焰的热流中氨的准确浓度。LIPF 技术的单次检测限估计在 1140 和 1750 K 的热烟道气中分别为 ~50 ppm 和 ~130 ppm，在室温氮气流中为 ~0.2 ppm。该技术用于检测燃料空气当量比为 1.2 的预混合层流氨-空气火焰中的氨泄漏。在后火焰区域检测到超过 5000 ppm 的未燃烧氨，测量结果与化学模型的预测非常吻合。