A series of experiments are carried out to find approach which can enhance absorption efficiency for transversally grooved tube (TGT) with different sizes

and to choose an optimal tube type. The experiment results show that aqua ammonia can absorb more ammonia gas and the mass transfer coefficient becomes larger with the increase of pressure difference and velocity of cooling water inside tube. When sprinkle density of aqua ammonia outside tube increases

mass transfer coefficient increases firstly and then decreases

so an optimum exists. The group experiments results indicate that transversally grooved tube have better mass transfer ability than smooth tube. For example

when sprinkle density of solution is 479.6kg/(m?h)

mass transfer coefficient of transversally grooved tube rise by 97.8% compared to smooth tube. A common law is discovered during three groups of experiment. Different sizes of TGT have different ability to absorb ammonia gas

and No. 2 tube is the best tube considering absorption efficiency. The ratio of groove width to diameter of this tube is 0.0814. Flow patterns of blend and vortex flow are compared among three transversally grooved tubes with solutions flowing through grooves

and the reason why TGT with different sizes have different absorption efficiency is obtained.