| The steel rolling reheating furnace is the main energy consuming equipment in the hot rolling process,and the energy saving and consumption reduction of the reheating furnace has always been the focus of research.At present,the main problems are: the difficulty of online determination of the cause and contribution of energy consumption changes,the long analysis period,and the low analysis efficiency,etc.,which make it difficult to achieve timely evaluation of the energy consumption of the reheating furnace.This article takes the walking furnace of Ma'anshan Iron and Steel's No.4 hot rolling mill as the research object,and mainly studies are the following contents:(1)Five key factors were analyzed: the influence mechanism of hot charging temperature,production rhythm,gas calorific value,flue gas oxygen content and furnace pressure control on heating furnace operation.The analysis was combined with production data.For example,on-site billet mixing was more frequent,and some were in alternate cold billet furnaces for heating,with cold billets accounting for 24% and hot billets accounting for about 10%.(2)Established a heating furnace online energy efficiency evaluation model system,including 12 calculation formulas,which could realize online evaluation.The intelligent diagnosis model analyzed and integrated the heat terms according to the burn up equation,and combined the mechanism analysis to determine the four key factors that affect energy consumption: output,furnace temperature,furnace temperature,and steel type.This article gave the specific calculation method of the contribution rate of each influencing factor: define the conditions of the baseline energy consumption,use the online data to calculate the energy value and actual performance value of the baseline energy consumption,and finally obtain the contribution of each influencing factor through normalization degree.(3)Through collecting and processing on-site production data,the change law of energy consumption of heating furnace were analyzed.Mainly include: ?1 When the billet rises from 45? to 600?,the unit consumption drops from 55kgce/t to 45kgce/t,a reduction of 18%;for every 100? rise in the billet temperature,the unit consumption decreases by 3.68kgce/t.?2 Each time the billet is increased by 10 minutes in the furnace,the gas unit consumption increases by an average of 7 MJ/t.?3 Every time the furnace output increases by 10 t,the unit consumption decreases by 0.22kgce/t on average.(4)Through a cloud platform and data reconstruction,a database was established.An online intelligent evaluation system for energy consumption was developed,could realize collect and calculate data in the hot-rolled area and display energy efficiency calculation results in real time.(5)According to the calculation results of the system,energy efficiency assessment and operation optimization cases were given.Mainly include: ?1 According to the calculation result of furnace pressure benchmarking rate,this paper put forward a plan for evaluating furnace pressure operation according to benchmarking level.?2According to the slab data and slab discharge temperature calibration and hot charging rate,and combined with the on-site operating procedure document,the operation of the heating process was optimized.?3 According to the air-fuel ratio index,combined with the recorded air gas data on site,the overall combustion level of the furnace was investigated,and the atmosphere in the furnace was optimized and regulated.It was proposed that for different fuels,the fluctuation range should be set separately,and then the atmosphere in the furnace should be adjusted in accordance with the management documents.(6)The use case of the on-site energy consumption evaluation system was given,and the intelligent evaluation results were displayed online and quantitatively.With the use of the system,the energy consumption of the production line was reduced by about 5%. |
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