Application of phase equilibrium theory in the heat-transfer process's analysis of heat-not-burn tobacco cigarettes

摘要

Heat-not-burn (HNB) tobacco cigarettes exhibit much lower level of harmful compounds in the mainstream smoke than those of conventional combustion cigarettes, and provide alternative less risky option for many smokers [l].The pyrolysis behaviors of HNB tobacco materials has been changed significantly by the addition of polyhydric alcohol, and existing literatures mainly focused on the analysis of aerosol's chemical compositions in a heat-not-burn tobacco product, while the effect of chemical reaction and mass transfer behavior on heat transfer characteristics have been rarely discussed [2-3]. In this study, the reconstituted tobacco and Flue-cured tobacco were used as experimental samples , and the relationship between the equilibrium moisture content and the relative humidity of the atmosphere was measured by water adsorption & desorption instrument. Moreover, the phase equilibrium theory was introduced to further optimize the One-dimensional Unsteady Heat Conduction Model of electric HNB tobacco cigarettes and find out the influence of water evaporation on heat transfer process in HNB tobacco cigarettes. The experimental results of internal temperatures of electric HNB tobacco cigarettes indicated that the average deviation between the predicted temperature and the measured value was 3.9 C, and the maximum deviation is 26.9 C. Moreover, the heat-transfer model's prediction accuracy of the fast heating stage and the platform peak near 100 degrees were both improved.