The evaporation heat transfer was experimentally investigated for the slim

cross

smooth and general micro - fin tubes in our study. The results show that the heat transfer coefficients increase with the refrigerant mass flow rate for all tested tubes. The heat transfer coefficient of the cross micro-fin tube is 10% higher than that of the slim micro - fin tube

and again the latter is 10% higher than that of the general micro - fin tube. The pressure drop of the cross micro- fin tube is higher than that of the other micro - fin tubes. Based on the steady state distributed parameter model and the same configuration and test conditions

the performance of evaporators using the these four micro-fin tubes were calculated and compared with each other. The results indicate that the performance of the cross micro - fin tube evaporator is superior to the other evaporators. The pressure drop for the four evaporators is almost identical with a slightly higher pressure drop for the smooth tube evaporator.