Heat Transfer Characteristics of Twin Circular Jet Impingement Cooling on the Strip Surface after Rolling

摘要

The heat transfer characteristics of the strip surface due to the twin circular jet impingement were numerically investigated by a three-dimensional finite element program. Systematic parametric research is conducted by varying the jet velocity of nozzle exit of 7.5 m/s, nozzle to the steel plate surface distance (H=6.7, 11.7, 16.7), and the nozzle to nozzle centre spacing (W=10, 15). The general trend of the distribution of the local Nusselt number and the average Nusselt number variation on the impingement surface of strip was obtained under the various parameters. The results show that, the heat transfer capacity of the strip surface perpendicular to the centre of the two jets decreases with the increase of the nozzle to nozzle centre spacing. The average Nusselt number increases by about 2%-20% with the increase of nozzle to the steel plate surface distance from 6.7 to 11.7 for the nozzle to the steel plate surface distance of 100mm and 200mm, while the average Nusselt number decreases by about 11%-25% with the increase of nozzle to the steel plate surface distance from 11.7 to 16.7.