Heat transfer characteristics and cooling capacity of online quenching equipment for plate

Abstract

The finite element method was taken to simulate the heat transfer characteristics and capacity of the online cooling equipment of a 3500 mm medium thickness plate production line. The cooling field on the steel plate surface could be divided into the impact zone and the wall jet zone after cooling water was sprayed on the surface of the steel plate. The impact zone had an intense heat transfer capacity because of the static pressure and the high radial velocity of cooling water. The maximum heat transfer coefficient (HTC) in the impact zone of spray and laminar cooling equipment could reach 20,334 and 10,096 W/(m² °C), respectively. In the wall jet zone, the radial velocity of cooling water was the main factor affecting the heat transfer capacity. With the decrease in velocity, the HTC decreased gradually. There is a linear relationship between the average HTC and the water flow. The average HTCs of spray and laminar cooling equipment in the common range of water flow were 5904–7255 W/(m² °C) and 3012–3369 W/(m² °C), respectively. The HTCs were verified in the 3500 mm medium thickness plate production line.