Thermal engineering of electronic cigarettes

Abstract

Electronic cigarettes were developed to vaporise an e-liquid containing nicotine. In addition to chemical composition, health and safety risks are associated with the power supply. The aim of this study was to determine the functioning limits using boiling correlations for the onset of nucleate boiling and critical-heat flux. These estimations are in contrast with the experimentally obtained values. To achieve this, forty-six atomisers were used and filled with a standardized e-liquid. The emissions were generated by supplying different power ratings, starting with a low power, which was increased for each new experiment until a malfunction occurred. The influence is characterised by the mass of the vaporised e-liquid (mass difference of the atomiser before and after the experiment). The results showed good agreement (33% and 19% in absolute deviations, 14% and −1% in relative deviations) between the boiling correlations (Sato and Matsumara, Zuber) and the functional limit of an E-cigarette. This link establishes how an E-cigarette is controlled through boiling. Determining the functional curve of a device should be a standardised requirement to show its physical limitations and would be a major contributor to reducing the risk of device use.