Computational fluid dynamics simulation of blast furnace shaft.

摘要

Computational fluid dynamics simulation is a tool to better understand the behavior of the gas-solid flow and in-furnace performance of blast furnace. This thesis consists of four parts. First, development and use of a mathematical model to predict the burden distribution which has a great effect on gas distribution and furnace efficiency. Second, simulate the blast furnace shaft process considering chemical reactions, heat exchanges, and gas-solid flow dynamics. Third, validate the burden distribution model and shaft simulation model using plant measurement. Fourth, to conduct parametric study of the major operational parameters i.e. effect of PCI rate, natural gas injection, bosh gas temperature, moisture add, oxygen enrichment, chimney size, and furnace geometry. Simulation is conducted using plant data and a good agreement is observed comparing with plant measurement. The parametric study showed that it is possible to improve the furnace performance by oxygen enrichment, adding moisture. It is also possible to decrease the coke rate by charging more PCI and increasing natural gas injection. Chimney size and furnace geometry can also affect a lot on the gas distribution and pressure drop. The burden distribution model and shaft CFD model can be used as a combination tool to predict the internal condition of a blast furnace.