Heat transfer and pressure drop in tubes fitted with grooved lobe rotor-assembled strands

The heat transfer enhancement of grooved lobe rotors and smooth tube were investigated in the integrated heat transfer performance test bench of shell-and-tube heat exchanger. The results indicated that heat transfer rate of tube with the grooved lobe rotors increased about 80-120% compared with that of smooth tube, but the coefficients of resistance also increased about 65-75%. It would be necessary to modify the structure of grooved lobe rotors in the future in order to obtain high heat transfer coefficient and a relatively low friction factor.