Papers by Author: Zhi Wen

Abstract: A hydraulic model is used to study the flowing process within a bottom-blowing furnace designed by a company, and the VOF model is adopted to simulate its process. The VOF method can describe the formation, growing up and separation actions in theorizing process by comparing the simulation and experimental results, and this is a foundation of using a model to research the thermal process of the bottom-blowing furnace. It is indicated that a nozzle with disperse spouts can stir a larger zone, by comparing the influence on flowing process of four nozzles with different structures. The disperse spouts are benefit to increase the stirring and reaction efficiencies, but the pressure fluctuations near the nozzle export is more obvious, and it may affect the lifespan of the nozzle.

Abstract: by studying steelmaking-casting-rolling production process, a mathematical model of integrated batch planning is established innovatively to minimize processing costs of whole line and computed by an intelligent optimization ant algorithm. On the premise of utilizing and coordinating capacity of steelmaking and rolling, the mathematical model of integrated batch planning can create integrated batch planning to combine steelmaking-casting-rolling closely according to each process constraint conditions and optimization objective. Furthermore, another mathematical model of job scheduling based on heat process model is proposed to not only guarantee the logistics balance between continuous casting and hot rolling, but also acquire the highest ratio of DHCR and lowest energy consumption.

Abstract: . A one-dimensional mathematical model was developed for describing heat and mass transfer process of lump coal falling in the freeboard zone of COREX melter-gasifier. The temperature distribution, law of moisture evaporation and removal of volatile of lump coal were obtained. Further more, the effects of operating parameters on heat and mass transfer phenomena of lump coal were studied.

Abstract: On the basis of wholly analyzing the mechanism of the heat transfer in the 1880 regenerative furnace, the physical and mathematical 3-D model was set up to describe the heat transfer and combustion in the furnace, and the CFD software was used to simulate the whole combusting process in detail. From this, the law of the flow affected by four classical switching modes was studied in emphasis. The conclusions in the study were helpful to the reasonably design and optimization controlling of such furnaces.

Abstract: On the basis of established mathematic model of regenerator heat transfer process, the process of heat transfer of ceramic honeycomb regenerator with the method of simulation is studied. The temperature distribution curve of regenerator and gas is obtained, the temperatures curve of regenerator and gas are closely related to time is investigated ,and the influence of operation and structure parameter to heat transfer of regenerator is discussed. All this work is to provide guides of rational design of single-ended regenerative burner.

Abstract: In this paper, a mathematical model is established to simulate heat and mass transfer process among the thin material layer consisting of zinc-containing pellets while being reduced in Rotary Heath Furnace (RHF). The material layer model is based on a single pellet model, coupling heat and mass transfer and chemical reactions. The model essentially involved solving the unsteady-state equations with appropriate initial and boundary conditions using the control volume formulation. Temperature distribution, gas phase concentration, metallization rate, and dezincing rate have been obtained and discussed.

Abstract: The continuous annealing process of strip steel is aimed to archive the required physical and mechanical properties. During this process, strip temperature is of great importance for controlling metallurgical transformation and grain size. This paper describes the modeling of the heating process in a horizontal annealing furnace used for producing stainless steel. The steady-state model is designed to predict strip temperature in the heating section, so it can simulate the annealing process of new varieties of steel never been produces. The strip temperatures predicted by model well correspond to the field data. This confirms the correctness and accuracy of the model.

Abstract: The Corex process, which consists of the upper reduction shaft and the melter-gasifier is an alternative ironmaking process to the blast furnace. The Corex melter-gasifier is a countercurrent reactor to produce liquid iron. Directly reduced iron(DRI), noncoking coal, and other additives are charged to the melter-gasifier at their respective temperature, and O2 is blown through the tuyeres. Moving bed of melter-gasifier is an important zone for reduction of iron oxide and melting of DRI, in which lump coal is a function as skeleton of moving bed replacing coke. A two-dimensional mathematical model was developed for describing gas flowing in the moving bed of Corex melter-gasifier. The gas velocity and pressure distribution were obtained. Further more, the effects of deadman porosity and cohesive zone, burden profile and height of moving bed above tuyere on the gas velocity and pressure distribution were studied.

Abstract: A three-dimensional mathematic model is developed for a 100kw single-end recuperative radiant tube and the simulation is performed with the CFD software FLUENT. Also it is used to investigate the effect of distance between combustion chamber exit and inner tube on heat transfer process. The results suggest that the peak value of combustion flame temperature drops along with the increasing of distance, which leads to low NOX discharging. Also radiant tube surface bulk temperature decreases, which causes radiant tube heating performance losses.

Abstract: The purpose of this paper is to discuss the application of oxygen-enriched combustion in metallurgic furnaces. Based on the knowledge of combustion and air separation, some advantages of oxygen-enriched combustion are carried on. In this work, the relation between energy efficiency and oxygen enrichment is presented, the result showed that furnaces can reach more than 10% energy saving by properly applying oxygen-enriched combustion technology. A system which combines the oxygen-enriched combustion technology and the CO2 capture with membrane separation technology is evaluated. In this system, the energy cost for CO2 capture can reach 0.9GJ/(t CO2). Finally, some problems that still need further study are also discussed.