強制振動燃焼の NO_x 低減効果(熱工学, 内燃機関, 動力など)

抄録

Pulsed combustion, which applies spontaneous oscillating combustion, is well known and is utilized practically in liquid heating while taking advantage of its high heat transfer rate and low NO_x emission. However, due to its high acoustic noise, the application is limited. We began this research with the idea that if oscillation was externally applied to combustion, advantages similar to those might be realized while controlling the noise level. Ruiz et al. and few other authors reported a decrease in NO_x emission when air ratio was changed cyclically and the reason for which was attributed to the occurrence of periodical lean-rich combustion. The purpose of this study is to clarify whether combustion with oscillation driven externally can effectively reduce NO_x emission, or whether its effectiveness may be limited to only exceptional conditions. Experiments were carried out in a high-temperature furnace, so that lower oscillation frequency could be realized. In addition, the oscillator was rebuilt so that conditions for fuel and air could be individually controlled.