An experimental rig was built and researches on the transport performance of bubble pumps with R134a/R23-DMF solutions and three lifting tubes of different inner diameters (6 mm

8 mm and 12 mm) were conducted. On the same concentration of solutions

the results showed the gas mass flow rate and the generating temperature increased approximately linearly with the increase of the heat input

the pumping ratio decreased approximately reversely with the increase of the gas mass flow rate

and the heat input had slight effect on system pressure. The concentrations of solutions had slight effect on the pumping ratio and generating temperature

but it had obvious effect on system pressure. The pumping ratio of the bubble pump and the poor R134a/R23 solution mass flow rate with lifting tube of 8 mm inner diameter has medium variation range compared with those of 6 mm and 12 mm lifting tubes

but the range of the gas mass flow rate was the widest and the generating temperature was the lowest. It showed that the bubble pump with lifting tube of 8 mm inner diameter was appropriate for the diffusion absorption refrigerator. The experimental results will be helpful to the design of bubble pumps for the diffusion absorption refrigerator.