Papers by Author: Xun Liang Liu

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: . 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: 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: Roller quench is a rapid cooling technique used in strip continuous heat-treatment process, which is one of the most important processes in producing cold-rolled strip steel. Heat transports by contact heat transfer in roller quench, for the complex characteristics of contact heat transfer, roller quench is very difficulty to simulate. In this paper a roller quench heat transfer model is build based on Fourier-Kirchhoff differential equations. A new correlation function of contact conductance is developed from statistical mechanics model results by least square method. This correlation function solves the heat transfer boundary condition in contact region between strip and roller. In this model the contact radiation is also considered. The roller quench model predicts the heat transfer characteristics of roller quench. The model is useful for the designing and controlling of the roller quench system.