Fluid Flow and Heat Transfer Behaviors under Non-Isothermal Conditions in a Four-Strand Tundish

Abstract

In the continuous casting process, the fluid flow of molten steel in the tundish is in a non-isothermal state. Because of the geometric shape and process parameters of a multi-strand tundish, the fluid flow behavior of each strand is quite inhomogeneous, and the difference in temperature, composition and inclusion content between each strand is great, which directly affects the quality of the steel products. In this paper, the fluid flow, heat transfer phenomena and inclusion trajectories in a four-strand tundish with and without flow-control devices (FCDs) are investigated using a water model and numerical simulation in isothermal and non-isothermal conditions. The results show that natural convection has a significant influence on the flow pattern and temperature distributions of molten steel in the tundish. Without FCDs, the average residence times of the molten steel in the tundish obtained by the isothermal water model, non-isothermal water model and non-isothermal mathematical model were 251.2 s, 263.3 s and 266.0 s, respectively, and the dead zone volumes were 21.51%, 29.26% and 28.21%, respectively. With FCDs, the average residence times of the molten steel obtained by the isothermal water model, non-isothermal water model and non-isothermal mathematical model were 293.0 s, 304.0 s and 305.2 s, respectively, and the dead zone volumes were 43.98%, 50.23% and 52.78%, respectively. The flow characteristics of the molten steel in the tundish were different between the isothermal and non-isothermal conditions. Compared with isothermal conditions, the numerical simulation results were closer to the water model results in non-isothermal conditions. The trial results showed that the fluid flow in a tundish has a non-isothermal characteristic, and the results in non-isothermal conditions can better reflect the actual fluid flow and heat transfer behaviors of molten steel in a tundish.

Digital Twin Design of a Turbulence Inhibitor in a Tundish Based on the Production Cluster Mining Algorithm

“…According to the theory of inclusion, the pressure, velocity, turbulence kinetic energy, vorticity, and divergence of the flow field around the inclusion have a significant effect on the trajectory and distribution of the inclusion [20,21]. Based on the calculation characteristics of CFD [22,23], the inclusion identity code was set as the main key in the inclusion database, and the inclusion database was constructed based on the star model.…”

Deeper Flow Behavior Explanation of Temperature Effects on the Fluid Dynamic inside a Tundish

“…Because of that, in recent years, more researchers have considered the temperature variable in their simulations versus most previous works, which ignore their effects [27][28][29][30][31][32][33][34][35][36][37][38][39][40][41][42][43][44][45]. Both approaches have generated debate about the importance of temperature on flow patterns among researchers [19][20][21][22][23][24][25][26]. Some assure that temperature effects strongly impact the flow patterns inside the tundish.…”

“…The temperature induces a strong inclusion coupling with the flow, which induces an increment in the removal inclusion rate. Zhu et al [23] use a four-strand tundish with baffles, finding that control devices can cushion but not eliminate the temperature impact.…”

Deeper Flow Behavior Explanation of Temperature Effects on the Fluid Dynamic inside a Tundish

“…Because of that, in recent years, more researchers have considered the temperature variable in their simulations [1-26] versus most previous works, which ignore their effects [27][28][29][30][31][32][33][34][35][36][37][38][39][40][41][42][43][44][45]. Both approaches have generated debate about the importance of temperature on the flow patterns among researchers [19][20][21][22][23][24][25][26]. Some assure that temperature effects strongly impact the flow patterns inside the tundish.…”