Effect of ethanol addition on flame characteristics of waste oil biodiesel

Abstract

Biodiesel is a kind of clean and renewable energy. The effect of ethanol addition on the flame characteristics of waste oil biodiesel is studied by using OH-PLIF technique from the perspective of OH radical evolution. Ethanol addition leads to the appearance of diffusion flame reaction interface ahead of schedule and shortens the diffusion flame height. The experimental results show a linear correlation between the flame height and the fuel flow rate for a given fuel and oxidant. The same conclusion is drawn from the theoretical analysis of the approximate model. In addition, ethanol addition makes the average OH signal intensity of flame at different fuel flow rate tend to be consistent and the fuel flow rate enlarge where the flame field shows the strongest oxidation performance. Average OH signal intensity begins to weaken at larger fuel flow rate, which indicates that fuel flow rate of fuels blended with ethanol can change in larger range and does not significantly affect the uniformity of combustion.