Ignition characteristics of vegetable fuel oils in fuel spray

The present paper concerns the ignition of single droplets of mixtures of rapeseed oil and fuel oil that was used as the biofuel. A special apparatus was built to measure fuel ignitability. On the basis of the measurements the ignition delay time of a droplet was determined as a function of temperature, biofuel composition and droplet size. The experimental results show that the biofuel composition as well as the ambient temperature in the experimental cylinder has a fundamental impact on the ignition phenomenon. Moreover, the results show that the droplet size is also of significance. The influence of the main factors on the delay time of ignition was given by an equation describing the ignition delay time as a function of temperature and the fuel oil fraction.