This study presents a contribution to the development of a model for vegetable oil droplets vaporization, with a particular focus on the influence of the experimental set-up for their use as fuel in diesel engines. Two systems were considered: an open-environment system obtained through a hot gas flow, and a closed-environment system. Vaporization was conducted under identical conditions, with the results subsequently compared. The findings indicate that, for temperatures between 473 K and 673 K, droplets behaviour in both systems presents only a heating and expansion phase. For temperatures above 673 K, the behaviour of the droplets differs between the devices. In the open environment device, a linear reduction in droplets diameter is observed following the transient phase, suggesting stationary vaporization and enabling the calculation of a vaporization constant and the well-known D 2 law is respected. In the closed-environment device, puffing, micro-explosions and gas ejections are observed, and it is not possible to determine vaporization constant and D 2 law is not respected. The results demonstrate the necessity of developing a model for the thermal decomposition of vegetable oil before attempting to create a model for the vaporization of these oils. In order to achieve this, it is essential to construct an experimental setup that more closely emulates the real conditions within the combustion chamber of a diesel engine, taking into account the variables of pressure, temperature and the heating process.

Experimental Device, Vaporization, Vegetable Oil, Open Enclosure, Closed Enclosure, Diesel Engine