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To get larger cooling performance enhancement for natural draft dry cooling tower with vertical cooling deltas under crosswind, setting angles of windbreak walls were optimized. Considering specific structure of each cooling delta, an efficient numerical model was established and validated by some published results. Aerodynamic fields around cooling deltas under various crosswind speeds were presented, and outlet water temperatures of the two columns of cooling delta were exported as well. It was found that for each cooling delta, there was a difference in cooling performance between the two columns, which is closely related to the characteristic of main airflow outside the tower. Using the present model, air inflow deviation angles at cooling deltas' inlet were calculated, and the effects of air inflow deviation on outlet water temperatures of the two columns for corresponding cooling delta were explained in detail. Subsequently, at cooling deltas' inlet along radial direction of the tower, setting angles of windbreak walls were optimized equal to air inflow deviation angles when no airflow separation appeared outside the tower, while equal to zero when outside airflow separation occurred. In addition, windbreak walls with optimized setting angles were verified to be extremely effective, compared to the previous radial walls.

The thermal resistances of the slag films and the air gap between the slab and the mold are important factors in heat transfer and lubrication control inside a continuous casting mold. The formation, evolution, composition and distribution of the slag film and air gap have significant influences on the initial solidification of the strand shell and slab quality. In this paper, based on experimentally measured thermocouple data and casting conditions, an inverse problem model of mold heat transfer is developed, with the purpose of accurately predicting the mold heat transfer states and slab solidification processes of actual casting conditions. Furthermore, a numerical model of the heat transfer between the air gap and the liquid/ solid slag films is developed, based on analysis of the formation mechanism, distribution and heat transfer characteristics of the air gap and slag films. The non-uniform distribution of the thermal resistance of the air gap and the liquid/solid slag films, and the heat conduction and heat radiation inside them are simulated, which provide a theoretical foundation for exploring the complicated heat transfer behavior and surface crack prediction during the continuous casting process.

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