计及物理参数变化的交流电弧炉全过程模型OA

The actual process operation of an electric arc furnace(EAF)shows a phased characteristic in terms of time sequence,but the electrical parameter fluctuations it causes run through the entire smelting process.Existing research mainly focuses on the power quality issues generated during the melting period,failing to effectively associate the multi-stage physical parameter changes with the electrical characteristic modeling throughout the entire process.The proposed AC EAF full-process model considering physical parameter changes in this paper mainly conducts physical process mechanism analysis from two aspects:the microscopic dynamic behavior inside the arc and the evolution law of the external morphology. In terms of microscopic dynamic behavior,arc discharge fundamentally constitutes a gas ionization process where the gaseous medium serves as both energy carrier and charge transport medium,with variations in its composition and concentration significantly influencing discharge characteristics;during EAF smelting operations,oxygen injection and reductant addition processes continuously alter arc zone gas concentrations while adjusting molten steel composition,thereby affecting microscopic particle dynamics within the arc.Regarding macroscopic morphological evolution,the influence of self-magnetic compression forces from arc current on radial force equilibrium is considered through magnetic compression force balance equations to analyze current effects on arc radius,while further examining the influence mechanisms of arc external characteristics across operational phases and segmented operational behavior on the arc,ultimately establishing a functional relationship for full-length arc variation to reflect governing mechanisms of external arc characteristics. The gas concentration needs to be detected using an infrared gas analyzer.However,the intense dynamic characteristics of the smelting process have led to the fact that the length of the electric arc has not yet been determined in a definite form.Therefore,based on the concentration relationships of N2,O2,CO2,and CO discovered by the infrared gas analyzer and combined with the oxidation-reduction reaction laws within the EAF,this paper constructs a gas concentration change curve through iterative time periods to characterize the three-stage decarburization process.Given the positive correlation between arc length and arc voltage,this paper analyzes the electrode operation methods and dynamic characteristics of the molten pool in different smelting stages to reveal the internal mechanism of arc length changes,and then modulates the range of arc length changes based on the fluctuation of arc voltage.The mechanism-data combination method is used to determine the gas concentration change curve and the arc length change function for each period during the EAF smelting process. This model was verified using the actual measurement data of a 55-ton EAF to test its accuracy and applicability throughout the entire smelting process.The results show that by combining the temporal changes in gas concentration and the phased evolution of arc length during each smelting stage,the actual operating state of the AC arc furnace in each stage can be described more precisely.Further,by verifying the influence of various gas concentrations that may occur during the oxidation and reduction periods on the electrical energy quality of the arc furnace,it was found that the gas concentration at specific time periods can effectively characterize the electrical energy quality characteristics of that period.This proves that considering the combined effects of gas concentration and arc length changes on arc characteristics is closer to the physical reality of arc furnace smelting.