Improving fuel utilization in steel mill operations using linear programming
Abstract This paper describes the use of linear programming to improve the fuel utilisation at a major Midwestern steel mill. In particular, linear programming is used to determine an efficient fuel allocation plan for this steel mill, which reduces the total fuel costs for the steel mill operations. The efficient fuel allocation plan that is developed utilises two externally purchased fuels: natural gas and fuel oil, and two gases: blast furnace gas and coke plant gas, which are internally generated as natural by-products of the production process. Test results from the application of the linear programming model are presented and discussed, and indicate that considerable cost savings can be achieved by utilizing a fuel allocation plan which more effectively utilizes the by-product gases which are produced within the steel making process.
Prediction and Optimal Scheduling of Byproduct Gases in Steel Mill: Trends and Challenges
Byproduct gases generated during the iron and steel making process are important energy sources in steel plant, which accounted for 30% of total energy consumption. With the increasing need for production cost control in steel industry, the refined management of byproduct gases has become prominent. The prediction and optimal scheduling of byproduct gases are two key factors in the optimal management of byproduct gases. However, due to the complexity and dispersivity of byproduct gas generation and consumption, it is difficult to build a comprehensive and reasonable prediction and scheduling model. This paper reviews current methods in the prediction and scheduling of byproduct gas system and discusses some of the key factors and opportunities in improving the model. Emerging trends that are likely to influence the current or future byproduct gas prediction and scheduling are also discussed.
Global attractivity in time-delayed predator-prey systems
Abstract For a predator-prey model with time-delay due to gestation, criteria are obtained for persistence and global attractivity. The global attractivity criteria apply only to models with a decreasing prey isocline.