In order to study the capillary-evaporation effect in the porous medium of electronic cigarettes, a theoretical model was established to simulate the heat and mass transfer process in the heating zone of e-cigarettes. Based on the similarity principle, a scaled-model test bench for e-cigarettes was designed and built. After comparing the numerical simulation results with experimental data, the saturation level and the transport rate of e-liquids in the heating zone were studied by applying the theoretical model.

The results showed that the numerical simulation results were basically in accordance with the experimental data. The theoretical model was proved to be reliable to some extent. The average vaporisation rate, average aerosol mass concentration and effective vaporisation heat efficiency increased linearly with the incremental increase of the heating power. Applying the same heating power and puffing regime, a higher propylene glycol content in the e-liquid resulted in a greater vaporisation rate and aerosol mass concentration. The heat efficiency (at same heating power) of propylene glycol was higher than that of vegetable glycerin. Most likely an increased porosity of the wick also increases the saturation level of e-liquid in the heating zone, which results in a higher capacity of the wick to absorb the e-liquid and therefore the probability of dry heating is reduced. The saturation level of the e-liquid in the heating zone is decreased symmetrically from both edges of the porous medium to its center. The transport rate of e-liquid at the beginning of the heating zone was higher than the rate in the center, therefore dry heating was most likely to occur at the center of the heating zone. The e-liquid saturation level in the heating zone decreased with the increase of the heating power. A higher heating power will therefore increase the probability of dry heating.