Energy Production And Consumption Model Of Steelmaking-rolling Process And Its Optimization

The steel industry is vital to China and is the backbone of many industries.It also plays an indispensable role in the entire process of human development.In 2018,crude steel production in China has increased,and world crude steel production has reached 1.08 billion tons.As a basic industry in China,the iron and steel industry strongly support the construction of China's manufacturing powerhouse.At the same time,the steel industry is an important industry of the national economy and a key industry for the country to promote energy conservation and emission reduction.The energy consumption of the steel industry accounts for about 15%of the country's total energy consumption,and there is still a gap of about 10%with the world's advanced countries.Therefore,in the social development and ecological civilization construction,the steel industry has put forward new and higher requirements for energy conservation and emission reduction.In the current research,material flow research or energy flow,research is often the main task,ignoring the idea of material and energy flow coupling,or research in the iron front process.This study is aimed at the post-iron process,and the steelmaking-rolling production process.The main equipment in the process is modeled by the principle of material conservation and energy conservation.The equipment integrates the idea of material flow and energy flow coupling,and then uses the database to link the process and the process.The model uses the Pyomo mathematical programming package based on the Python high-level programming language to build the MINLP model,which is solved by the Ipopt solver of the interior point method.The model verification results show that the relative error is within 10%,indicating that the model meets the actual production requirements.Through optimization of the process through the model,the energy consumption during the steelmaking process is reduced by 5.42%,the energy consumption of the hot rolling process is reduced by 9.80%,and the energy consumption of the steelmaking-rolling process is reduced by 26.57%.After the introduction of the direct rolling process,the energy consumption of the process of the steelmaking-rolling process decreased by 140.39%.The negative energy manufacturing of the steelmaking-rolling process is realized.At the same time,the direct rolling process is optimized to reduce the energy consumption of the direct rolling process by 8.08%.Secondly,in the study on the energy and material migration of major equipment,the sensible heat of the converter in iron removal accounted for 55.43%,the remaining 44.57%was provided by the chemical reaction heat,and the steel slag accounted for 7.62%in the output heat;the sensible heat to the furnace air and the sensible heat of the billet it accounts for 18.64%and 19.09%of total heat.The b-P model is used to analyze the relationship between the main equipment consumption and the load,and the optimal"economic point" of the heating furnace and the direct heating furnace is obtained.Further,eight parameters,including the material inlet temperature of the main equipment,the scrap ratio of the converter,and the calorific value of the mixed gas of the heating furnace were selected to analyze the influence on the energy consumption of the process.When the temperature of the molten iron in the furnace is at 1330?,the energy consumption of the process is the lowest.When the temperature of the molten iron in the furnace is 1400?,the energy consumption of the process is the highest;the amount of scrap added is adjusted according to the temperature of the furnace,and the ratio of scrap to steel is increased at different temperatures.Energy consumption is on the rise.When the heating furnace does not use one kind of gas,the impact on the process energy consumption can be neglected.When the heating value of the mixed gas is increased within a certain range,the process energy consumption will decrease accordingly;the influence of the billet temperature on the process energy consumption Larger,from 25?to 900? process energy consumption decreased by 72.27%;increased waste heat recovery rate for the process energy consumption is linear.The temperature difference between the head and the tail of the straight rolling process increases by 50?,the energy consumption of the process increases by 0.35 kgce·t-1,the temperature of the furnace increases by 70?,the energy consumption of the process decreases by 1.86 kgce·t-1,and the heating time of the head and tail is reduced by 15 s and 18 s respectively.