According to the features of melting process of regenerative aluminum melting furnaces, a three-dimensional mathematical model with user-developed melting model, burner reversing and burning capacity model was establi...According to the features of melting process of regenerative aluminum melting furnaces, a three-dimensional mathematical model with user-developed melting model, burner reversing and burning capacity model was established. The numerical simulation of melting process of a regenerative aluminum melting furnace was presented using hybrid programming method of FLUENT UDF and FLUENT scheme based on the heat balance test. Burner effects on melting process of aluminum melting furnaces were investigated by taking optimization regulations into account. The change rules of melting time on influence factors are achieved. Melting time decreases with swirl number, vertical angle of burner, air preheated temperature or natural gas flow; melting time firstly decreases with horizontal angle between burners or air-fuel ratio, then increases; melting time increases with the height of burner.展开更多
Numerical simulation is applied to gas-particle flows of the primary and the secondary air ducts and burner region, and of two kinds of swirl burners. The modeling results of Radial Bias Combustion (RBC) burner well a...Numerical simulation is applied to gas-particle flows of the primary and the secondary air ducts and burner region, and of two kinds of swirl burners. The modeling results of Radial Bias Combustion (RBC) burner well agreed with the data from the three-dimensional Phase-Doppler anemometry (PDA) experiment by Li, et al. The modeling test conducted in a 1025 t/h boiler was to study the quality of aerodynamics for a Central Fuel Rich (CFR) burner, and the Internal Recirculation Zone (IRZ) was measured. In addition, gas-particle flows with a CFR burner were investigated by numerical simulation, whose results accorded with the test data fundamentally. By analyzing the distribution of gas velocity and trajectories of particles respectively, it is found that the primary air’s rigidity of CFR burner is stronger than that of RBC burner, and the primary air mixes with the secondary air later. Furthermore, high concentration region of pulverized coal exists in the burner’s central zone whose atmosphere is reduced, and trajectories of particles in IRZ of CFR burner are longer than that of RBC burner. They are favorable to coal’s ignition and the reduction of NOx emission.展开更多
The influence of oxygen supply mode on the KIVCET (a Russian acronym for flash?cyclone?oxygen?electric?smelting) process was investigated using numerical simulation. The mass rate ratio (MRR) of central oxygen to late...The influence of oxygen supply mode on the KIVCET (a Russian acronym for flash?cyclone?oxygen?electric?smelting) process was investigated using numerical simulation. The mass rate ratio (MRR) of central oxygen to lateral oxygen of the central jet distributor (CJD) burner was defined to express the oxygen supply mode, and the KIVCET process with an MRR ranging from 0.09 to 0.39 was simulated. The results show that there are four efficient reaction regions that correspond to four CJD burners. A higher central oxygen flow improves the mixing between particles and oxygen, thus enhancing reactions and shortening the reaction regions. However, a higher dust rate is induced due to the spread of the particle columns. The optimal MRR for a KIVCET furnace with a smelting capacity of 50000 kg/h is suggested to be 0.31. In this case, the chemical reactions associated with the feed are completed with an acceptable dust rate.展开更多
基金Project(2009bsxt022)supported by the Dissertation Innovation Foundation of Central South University,ChinaProject(07JJ4016)supported by Natural Science Foundation of Hunan Province,ChinaProject(U0937604)supported by the National Natural Science Foundation of China
文摘According to the features of melting process of regenerative aluminum melting furnaces, a three-dimensional mathematical model with user-developed melting model, burner reversing and burning capacity model was established. The numerical simulation of melting process of a regenerative aluminum melting furnace was presented using hybrid programming method of FLUENT UDF and FLUENT scheme based on the heat balance test. Burner effects on melting process of aluminum melting furnaces were investigated by taking optimization regulations into account. The change rules of melting time on influence factors are achieved. Melting time decreases with swirl number, vertical angle of burner, air preheated temperature or natural gas flow; melting time firstly decreases with horizontal angle between burners or air-fuel ratio, then increases; melting time increases with the height of burner.
基金Sponsored by the Ministry of Education of China via the 2004 Year New Century Excellent Talents in University (Grant No NCET-04-0328)Hei-longjiang Province via 2005 Year Key Projects (Grant No GC05A314)
文摘Numerical simulation is applied to gas-particle flows of the primary and the secondary air ducts and burner region, and of two kinds of swirl burners. The modeling results of Radial Bias Combustion (RBC) burner well agreed with the data from the three-dimensional Phase-Doppler anemometry (PDA) experiment by Li, et al. The modeling test conducted in a 1025 t/h boiler was to study the quality of aerodynamics for a Central Fuel Rich (CFR) burner, and the Internal Recirculation Zone (IRZ) was measured. In addition, gas-particle flows with a CFR burner were investigated by numerical simulation, whose results accorded with the test data fundamentally. By analyzing the distribution of gas velocity and trajectories of particles respectively, it is found that the primary air’s rigidity of CFR burner is stronger than that of RBC burner, and the primary air mixes with the secondary air later. Furthermore, high concentration region of pulverized coal exists in the burner’s central zone whose atmosphere is reduced, and trajectories of particles in IRZ of CFR burner are longer than that of RBC burner. They are favorable to coal’s ignition and the reduction of NOx emission.
基金Project(61621062)supported by the Foundation for Innovative Research Groups of the National Natural Science Foundation of China
文摘The influence of oxygen supply mode on the KIVCET (a Russian acronym for flash?cyclone?oxygen?electric?smelting) process was investigated using numerical simulation. The mass rate ratio (MRR) of central oxygen to lateral oxygen of the central jet distributor (CJD) burner was defined to express the oxygen supply mode, and the KIVCET process with an MRR ranging from 0.09 to 0.39 was simulated. The results show that there are four efficient reaction regions that correspond to four CJD burners. A higher central oxygen flow improves the mixing between particles and oxygen, thus enhancing reactions and shortening the reaction regions. However, a higher dust rate is induced due to the spread of the particle columns. The optimal MRR for a KIVCET furnace with a smelting capacity of 50000 kg/h is suggested to be 0.31. In this case, the chemical reactions associated with the feed are completed with an acceptable dust rate.
