The Simulation Study On Heat Transfer Of Blast Furnace Wall Circulating Water Cooler

With the development of China’s economic society, the energy and water resources problems become more and more severe. As the guaranteed system of blast furnace ironmaking equipment, circulating cooling water system is closely linked with steel enterprises production safety. Blast furnace wall circulating water cooler, scilicet closed cooling tower is the main heat transfer equipment of the system. Its compact structure can save occupied area and energy consumption of water pump. Furthermore, water in the pipe can’t be polluted because of indirect contact. The equipment has a remarkable water saving effect because water can be used directly after cooling. On the premise of production safety, strengthening its heat transfer effect as soon as possible is significant for reducing energy and water resources consumption.There are more experimental studies on closed cooling tower at present. The numerical simulation studies on two-dimensional physical fields. But it is not suitable for all tower types. This paper preliminary studied on its heat transfer situation by CFD. Comprehensive consideration the existing study results and condition limits, a miniature three-dimensional model of cooler is established after appropriate simplifications. And the cooling effect of spray water and air on the cooling water in heat exchange coil are studied separately. By changing the inlet velocity of spray water and air to control their amount, the influences of three factors on heat transfer situation of cooler are studied by using numerical simulation technology. They are the amount of spray water, the temperature of spray water and the amount of air.It is concluded that the influences of these factors on heat transfer situation through numerical simulation.(1) With the increase of spray water amount, the temperature difference of cooling water at the heat exchange coil inlet and outlet is increasing. And the heat transfer effect of the cooler becomes better, but the overall trend slowed down. Comprehensive consideration the effect of heat transfer and economy, the optimal range of the spray water inlet velocity is determined. The optimal range of the spray water amount is also determined.(2) The heat transfer situation is different at different location, which the two-dimensional simulation studies can’t consider.(3) With the increase of spray water temperature at inlet, the temperature difference of cooling water at inlet and outlet is decreasing. And the heat transfer effect of the cooler becomes worse. Consequently, the spray water temperature should be monitored to avoid it becoming too high in the actual process.(4) With the increase of air amount, the temperature difference of cooling water at inlet and outlet is increasing. And the heat transfer effect of the cooler becomes better. In the actual process, there is a small amount evaporation of spray water under the interaction of spray water and air. Thus the heat transfer effect of the cooler becomes better.The numerical simulation results of this paper provide a directional guidance for practical research. The study of this paper provides reference for three-dimensional numerical simulation of closed cooling tower. However, the three-dimensional simulation of the whole structure is remains to be further studied.