Numerical Simulation of Heat Transfer of High-Temperature Slag Flow Inside the Blast Furnace Slag Trench

To investigate the flow and heat transfer process of blast furnace slag through the slag trench after the slag is discharged,a three-dimensional physical model is established and simulated according to the actual size of the slag trench and the physical properties of the high-temperature slag.The temperature field and flow field distribution of the high-temperature slag liquid inside the slag trench is obtained by numerical simulation under different working conditions,and the effects of operating conditions such as slag trench inclination,high-temperature slag inlet flow rate,and inlet temperature are investigated.The results show that the flow rate of high-temperature slag is related to the slope of the slag trench,the greater the slope of the slag trench,the higher the flow rate of high-temperature slag,in which the highest average speed can reach 2.23 m/s when the slope is 8%;changing the inlet flow rate,flowing through the slag trench,the high-temperature slag reaches the highest flow rate at the same position,the overall flow rate changes tend to rise first and then decrease,and the greater the inlet flow rate,the higher the temperature change of high-temperature slag.The higher the inlet flow rate,the higher the temperature change of high-temperature slag,the higher the temperature of high-temperature slag out of the slag trench;the higher the inlet temperature,the higher the overall flow rate of high-temperature slag,and the position of the highest flow rate is relatively backward.

Thermal characteristics and thermal stress analysis of solar thermochemical reactor under high-flux concentrated solar irradiation

Nowadays, using a solar-driven thermochemical reaction system to convert greenhouse gases into high-quality liquid fuels has been proven to be an effective way to address the growing depletion of traditional fossil fuels. However, the utilization of highlyconcentrated solar irradiation runs the high risk of reactor damage issues resulting from thermal stress concentration, which seriously threatens the security and reliability of the total reactor system. In this study, the thermal radiation distribution and thermo-mechanical process in a volumetric reactor were numerically investigated by combining Monte Carlo ray-tracing method with computational fluid dynamics method. Based on the experimental results and thermal characteristic analysis, the formation mechanism of thermal stress concentration and the strategies of improving thermal stress distribution were discussed in detail.The simulation results indicate a great possibility of reactor damage at about 1000℃ operating temperature and 9.0 k W lamp power, which is well-matched with related experimental results. The ceramic damage typically occurs at the inner edges of the through-holes, including the aperture, the gas inlet, and the thermocouple hole, then extends along the lines connecting these holes and finally causes brittle fracture. By reasonable control of the opening direction and the distance between the throughholes, the maximum compressive stress can be reduced by 21.78%.