Binglin Zheng

An Effective Approach for the Scheduling of Steel-making and Continuous Casting System with Stochastic Processing Requirements

Abstract The steel-making and continuous casting system (SCCS) is the bottleneck in the iron and steel production, SCCS often involve various uncertainties such as the emergency customer orders, inaccurate estimate of ingredient components, the unpredictable machine breakdown or the inaccurate estimate of processing time. How to consider such uncertainties to build a better schedule in a limited time by a computationally efficient manner is becoming critical for the production of iron and steel. The stochastic dynamic programming method is adopt to solve the obtained subproblems which are relaxed by Lagrangian relaxation multipliers, a good dual solution is selected by using “ordinal optimization,” and the actual schedule is dynamically constructed based on the dual solution and the realization of random processing requirements. The method has been tested by using practical data from the Shanghai Bashan steel plant in China and could get near optimal solutions in a limited time; the stochastic processing requirements are effectively handled for the production.

A two-stage heuristic method for vulcanization production scheduling

There are more product specifications, great production and much equipment over the whole process of rubber tire vulcanization. Aiming at rubber tire vulcanization production scheduling single-process, parallel machines scheduling problem with special process constraint, a two-stage scheduling strategy of vulcanization production, the load distribution of equipment and operation plans sequencing, is proposed. Equipment load distribution model of vulcanization machine based on 0–1 integer programming is built and improved maximum elimination algorithm is proposed. Operative plan sorting model based on 0–1 integer programming is built and an optimal algorithm based on minimum delay time is proposed. The algorithm was tested by online data. Results show that the two-stage scheduling method can quickly workout the optimal scheduling planning of vulcanization, reduce the production cost, and improve productivity. The method will lay the firm groundwork for application to production process in the future.

Cast Batch Planning for Steelmaking and Continuous Casting Based on Ant Colony Algorithm

A multi-objective 0-1 integer programming model is established in order to solve the complex problem of cast batch planning for steelmaking and continuous casting which is considered as vehicle routing problem. To solve the complex multi-constrained, multi-objective cast batch planning model for steelmaking and continuous casting, a method is proposed which combines rules with ant colony algorithm. The algorithm is tested by online data. Results show that the proposed algorithm can quickly workout the optimal cast batch planning for steelmaking and continuous casting, and can lay the firm groundwork for application to production process in the future.

Guided variable neighborhood harmony search for integrated charge planning in primary steelmaking processes

The planning for rectangular plate products (slabs) in an integrated steel plant is extremely hard and important. Due to the large scale and complex integrated operational constraints, the planning problem is quite difficult to achieve an optimal solution even a feasible solution. From the practical point of view, this paper discusses an integrated charge planning (ICP) problem, with flexible product specifications. The purpose is to improve the efficiency and feasibility of planning, the customer satisfaction levels and the production costs, considering the integrated operational constraints. An integer programming model is formulated, and the problem is NP-hard. A new heuristics based on a variable neighborhood search (VNS), named the guided VNS embedded in harmony search, is designed. The computational results demonstrate that the proposed model and algorithm are feasible and effective for ICP.

Model and algorithm of integrated lot planning for steelmaking-continous casting-hot rolling

Integrated lot planning(ILP) for steelmaking-continous casting-hot rolling(SM-CC-HR) is analyzed and a prize collecting vehicle routing problem model is proposed. The model considers a lot of SM, CC and HR production process constraints.An improved MAX-MIN Ant System(IMMAS) with Variable Neighborhood Search(VNS) is introduced for the model.In the IMMAS, The heuristic information is constructed according to the rules to give slabs with less penalty, higher surface grade and higher priority. The experimental results show that the proposed model and algorithm are effective, the satisfying solutions can be obtained within acceptable time.

Simulation system for logistics in steelmaking process based on Flexsim

Because of the complexity, dynamicity and uncertainty of the steelmaking process, it is difficult to establish the simulation model to express most characteristics of the mixed production system for mathematical method. This paper researches the steelmaking logistics model which includes production equipment and production process, and establishes the simulation system for logistics in steelmaking process based on Flexsim which includes the process simulation, human-computer interaction and decision-making. The simulation results have shown the efficiency of the simulation system by practical production data. The simulation system supplies the object experimental platform for the study of steelmaking scheduling methods which are suitable for practice.

Model and algorithm for integrated charge plan in the steel industry

According to the demand of integrated production and the characteristic of charge plan in the steel industry, firstly, use graph theory to describe charge plan; secondly, a bi-objective charge plan model is introduced in detail considering weight range, flow limitation and other factors; To solve this model, a two-phase heuristic algorithm (THA) is introduced, which deals with the simple graph with vertex clustering method firstly, and then design a novel probability match algorithm to solve the optimization model; Finally, the simulation with large-scale production data shows that the model and algorithm is feasible.

Study on dynamic scheduling stimulation of steelmaking and continuous casting

This paper researches the dynamic scheduling of the steel-making and casting stimulation. It includes the disturbances productions, disturbances processing, processing evaluation and feedback adjustment. In the disturbances productions, it has the four functions, including the setting process, the disturbance intensities productions and devices information production. It designs the production module of the steel-making scheduling disturbances. In the disturbance process, it includes the disturbances pre-processing, the disturbance processing functions in the low intensity period, the high intensity period and the top high intensity period. It includes the optimization module of casting and flowering time, the optimization module of steel-making scheduling redundancy time and adjustment policy of the flowering-intelligence.

Research on molten iron logistics balance model in iron-steel correspondence scheduling

Molten iron logistics balance is one of iron & steel production planning and scheduling problems. It lies on the first layer in iron-steel correspondence scheduling system. Productivity constraints of blast furnace and steel-making, demand weight constraints of molten iron for steel-making, weight constraints of on-line molten iron were comprehensively considered and a multi-objective mathematical programming model of molten iron logistics balance problem was established. The multiple objectives including maximizing productivity of blast furnace and steel-making and minimizing transportation cost were taken into account in the model. By conversion method the model was converted into linear programming which can be solved by standard linear programming software. And the evaluation indices of model were computed. The experimental results using practical production data show the proposed model is effective and feasible.

Method for hot rolling planning considering material requirements of downstream production lines

Hot rolling planning in steel and iron production process is analyzed and a prize-collecting vehicle routing problem model with uncertain rolling planning numbers for hot rolling planning is presented with balancing the workloads of downstream production lines as one objective. The model considers the jump limit of discharging temperature, finishing rolling temperature and coiling temperature of adjacent slabs, the rolling position of slab surface grade and mix rolling of multiple rolling type slabs, but also considers the reasonable arranging of warm-up materials and staple materials. A two-stage algorithm based on Variable Neighborhood Tabu Search is designed to solve the model. Computational experiments with industrial data show the effectiveness of the proposed model and algorithm.