Numerical Simulation Study on the Interaction Mechanism and Effects on Co-Injection of Pulverized Coal and Hydrochar in the Raceway of Blast Furnace

To solve the energy crisis and slow down the greenhouse effect, it is urgent to find alternative energy sources for the iron and steel production process, hydrochar is an auxiliary fuel and only renewable carbon source that could reduce the injection of bituminous coal into the blast furnace. Numerical simulation is an effective method of understanding the combustion performance in the lower part of the blast furnace, A 3D blowpipe-tuyere-raceway model was established using the computational fluid dynamics (CFD) method to study the interaction mechanism and influence of combustion performance between pulverized coal and hydrochar. The results showed that co-injection of anthracite and hydrochar has a better combustion performance than co-injection of anthracite and bituminous coal, with a more appropriate distribution of temperature, velocity, and gas phase, as the co-injection of hydrochar, the average burnout rate and anthracite burnout rate increased respectively by 6% and 2.1%, which is caused by the interaction mechanism between anthracite and hydrochar. As a result, hydrochar as an auxiliary fuel for blast furnace injection can not only achieve low-carbon production and cut down carbon emission but also promote the combustion process of pulverized coal.