The spinning forming process and he

The spinning forming process and heat transfer performance of 准7mm inner-grooved copper tube with slimmer tooth and larger helical angle were investigated by optimization of die design, process test, observation of tooth profile parameters and heat transfer performance test of single tube. The results show that 4-ball spinning forming process is more suitable for the forming of 准7mm inner-grooved copper tube with slimmer tooth and larger helical angle than 5-ball spinning forming process. During the 4-ball spinning for 准7 mm (external diameter)×0.24mm (wall thickness)×0.15 mm (tooth depth) inner-grooved copper tube with 58 teeth, 11° addendum angle and 30° helical angle, the best rotation-pulling speed ratio is 600. The heat exchange capability of trial-produced sample is obviously improved than the same ordinary tube. Especially, the average condensation heat transfer coefficient increases by 16.99%, while the pressure loss increases slightly