2017 Volume 17 Issue 3 Pages 210-216
From the engineering point of view, an image diagnose of burner-tip temperature is highly demanded to avoid thermal damage during operation. This study proposes an estimation method of burner-tip temperature based on shape evaluation of non-premixed microflame. An energy balance model involving the heat transfer through side and top of the burner is considered to derive a simple formula to estimate the burner-tip temperature from the flame shape. The methane microflame is experimentally observed under various conditions of ambient air temperature and fuel velocity. Obtained images are quantified by image analysis and three kinds of parameters which characterize the flame shape are successfully determined; the effective radius, the flame height and the quenching distance. The burner-tip temperature is then estimated by the proposed formula under each experimental condition. The estimated burner-tip temperatures show fairly good agreement the measured temperatures by thermocouple. This result suggests that the proposed method based on observation of the microflame allows reasonable estimation of the burner-tip temperature.
