To study the heat and mass transfer characteristics of an R134a-DMF (Dimethylformamide) bubble absorption process in a vertical tube

an experimental device for bubble absorption in a vertical tube was fabricated

and a mathematical model of heat and mass transfer in the bubbling absorption process of R134a by an R134a-DMF solution was established. The characteristics of flow patterns of churn flow

slug flow

bubble flow

and single-phase flow were simulated and analyzed at an absorption pressure of 0.35 MPa

a vapor inlet temperature of 5 °C

and a weak solution inlet mass flow rate of 12.0 kg/h

by which the variation in absorption height with inlet parameters was obtained. The proportion of slug flow to the absorption height was the largest in the absorption process. As the absorption process continued

the rate of absorption increased. The variation in the vapor temperature was the largest

followed by the variations in phase interface temperature and solution temperature

and the variation in the cooling water temperature was the smallest. Furthermore

the variations at different temperatures were the largest in the churn flow state and the smallest in the bubble flow state. At the weak solution inlet mass fraction of 0.4 and the weak solution inlet temperature of 45 °C

the absorption height increased from 0.44 m to 1.88 m when the vapor inlet mass flow rate varied from 1.0 kg/h up to 2.5 kg/h.