| Steelmaking-continuous and casting-hot rolling is the three main processes of tight connection in iron and steel production.The corresponding integrated plan of steelmaking-continuous casting-hot rolling needs to further improve the matching level and smooth operation efficiency of iron and steel production logistics by taking into account the production objectives and process constraints of different processes,forming furnace scheduling,casting planning and hot rolling unit planning that can organize production in batches.However,because the planning process is a multi-stage,multi-objective and multi-constrained complex combinatorial optimization problem,and the production objectives and process constraints among steelmaking,continuous casting and hot rolling processes are mutually promoting and restricting,it is very difficult to compile the integrated batch plan of steelmaking,continuous casting and hot rolling.Therefore,it is of great significance and application value to carry out the research on the integrated batch planning method of steelmaking,continuous casting and hot rolling.In this paper,the problem of batch planning of steelmaking-continuous casting-hot rolling is studied with hot strip as the object.The problem of planning of steelmaking-continuous casting,hot rolling planning and integration of steelmaking,casting and rolling are studied by decomposition-coordination method,and the models and optimization algorithms are established respectively.The main research contents and results are as follows:Aiming at the problem of furnace scheduling,a multi-objective optimization model is established,which aims at minimizing the jump penalty of rolling width,the deviation penalty of delivery time and the quantity of non-committees,and a multi-objective optimization model aiming at minimizing the penalty of difference of delivery time and the number of pouring times is established.The steelmaking-continuous casting production planning problem is reduced to a multi-objective multi-traveling salesman problem.An improved multi-objective ant colony algorithm is designed to solve the problem.The effectiveness of the model and the algorithm is verified by test examples of different scales.Aiming at the problem of hot rolling planning,a multi-objective optimization model was established to minimize the thickness jump penalty and hardness jump penalty of hot rolling slab.An improved multi-objective genetic algorithm based on NSGA2 is designed by using probability conflict resolution strategy,elite retention strategy,neighborhood search and other strategies.The optimization strategies of single hot rolling unit and between hot rolling units are proposed to further accelerate the convergence of the solution and improve the optimization ability of the solution.The test results show that the model and algorithm can effectively reduce the penalty of size jump and hardness jump of hot rolled slab.The coordinated matching model of steelmaking,continuous casting and hot rolling is established,and the concept of "time difference between casting and rolling" and the calculation parameters are put forward.By using this parameter,the optimization solution of the integrated plan can be guided to converge in the direction of "increasing hot charging rate",and the joint coordination of steelmaking,continuous casting and hot rolling production plans can be realized.The simulation results of different scale cases show that the hot charging rate of slab can be improved by effectively reducing the "casting-rolling time difference" of slab. |
