Numerical simulation of the structure optimization of double cavity tuyere in large size blast furnace

The blast furnace tuyere, the key equipment of the blast furnace (BF) cooling system, endures a severe working environment and frequently lends itself to damage. Therefore, improving the service life of tuyere is very important for the long-term stable operation of the blast furnace. This paper establishes a three-dimensional BF double cavity tuyere model based on the computational fluid dynamic method. First, the temperature and velocity distribution characteristics of the tuyere are simulated. Then, the influence of the cooling capacity is investigated by changing the front cavity height, front cavity width, inlet and outlet diameter, and distance from the front cavity baffle. The results indicate that increasing the height of the front cavity of the tuyere is beneficial to improve the cooling capacity of the tuyere. For every 1 mm increase in the front cavity of the tuyere, the tuyere temperature decreases by about 3.4 K. Moreover, appropriately increasing the front cavity width and decreasing the diameter of the cooling water can reduce the temperature of the tuyere. Changing the distance between the inlet and outlet and the baffle has little effect on the cooling capacity of the tuyere. Through comprehensive structural optimization, the temperature and stress of the tuyere are reduced by 21.2 K and 31.65 MPa, respectively. Improving cooling capacity is a combination of several factors. The key factors affecting the cooling of the tuyere are the heat transfer area and the renewal rate of the cooling water.