Cooling characteristics of hot rolled seamless steel tube by jet impingement

The flow and temperature field variation of hot rolled seamless steel tube with outer diameter of 140 mm and wall thickness of 10 mm were studied by experiment and numerical simulation. The finite element model of circular jet impinging cooling steel tube was established, and the steel tube was divided into different regions in circumferential direction. It was found that the uniformly arranged multiple jets have non-uniform cooling characteristics under the influence of gravity and hollow characteristic. Under the condition of 12 jets, the average heat transfer coefficient in circumferential direction of -15 similar to -45 degrees region is 8385 W/(m(2)K), and the fluctuation of the average heat transfer coefficient in different regions reaches 3222 W/(m(2)K). According to statistical average cooling rate of the experiment, the average cooling rate increases by 34% when 2 jets are increased to 4 jets. When the number of jets exceeds 8, increasing the number of jets has a limited effect on improving average cooling rate. Through reasonable configuration of jet velocity of different nozzle positions, a way to realize uniform cooling was proposed and preliminarily verified. The improved average heat transfer coefficient fluctuation of circumferential was limited to 1000 W/(m(2)K), which significantly improved the uniformity of jet cooling.