Research on characteristics of flow boiling and dryout inhibition of rifled tube

Abstract The two-fluid three-flow field mathematical model is used to carry out the numerical simulation of heat transfer characteristics of steam-liquid two-phase flow in dryout and post-dryout region of the rifled tube. The absolute vorticity flux and intensity of the secondary flow are introduced to quantitatively characterize the heat transfer enhancement. The results show that, compared with smooth tube, the rifled tube can greatly reduce the rise of wall temperature and have a significant effect on dryout inhibition. The cross-section wall temperature of rifled tube presents a periodic distribution. The wall temperature at the intersection of the root and rib side is higher due to the fluid retention. After the dryout occurs, the wall temperature is higher than other locations due to the continuous liquid film on the crest being torn. The secondary flow strength and heat transfer enhancement degree of fluid in rifled tube increase with the increase in axial height. The absolute vortex flux, intensity of the secondary flow and absolute value of the vorticity in main flow direction can reflect the degree of fluid disturbance caused by internal thread.