Production Planning Method for Steelmaking-continuous Casting Process Based on Time Backward and Process Simulation

Reasonable production planning effectively ensures smooth operation. According to the analysis of the characteristics of steelmaking-continuous casting production process, a production planning method for steelmaking - continuous casting process based on time backward inference method and process simulation is presented. Production plan meeting certain criteria is rapidly gained by time backward inference method, and is regarded as input of simulation model in steelmaking process. Considering time randomicity in production process and transporting equipment restriction, production plan meeting more restrictive conditions, such as no equipment conflict, continuous casting, and etc, is acquired through simulating. It assures that the plan is carried out in practice. The instance demonstrates the feasibility of the method.     

The Numerical Simulation Commercial Software for Secondary Cooling Process in Billet Continuous Casting

A numerical simulation commercial software has been developed by the object-oriented Visual Basic programming language on the basis of the 2D mathematical model of secondary cooling Process in billet continuous casting. Thereby an effective experimenting tool for computer simulation of continuous casting process is gained. By simulation with the software, the caster structures and operating parameters in continuous casting can be designed and optimized. The simulating calculation examples on several casters and its production applications indicate that the commercial software developed has more accuracy, practicability and commonality, as also as simpler operating capability. The simulated results have been successfully applied to the design and production of the high-efficiency modification for several billet casters interiorly.     

Simulation optimization for input plan of multi type and batch production with flexible process

Aiming at multi type and batch production system with flexible process, an optimization method for input plan based on Witness simulation is proposed. The scientific problem researched is described. Aiming at the characteristics of multi type and batch production with flexible process, the simulation logic is designed. Taking Witness as simulation platform, the simulation model combining input plan with scheduling for multi type and batch production is constructed. The effectiveness of the method is tested by simulation examination.     

Simulation for Logistics in Steel-making Process of Panzhihua Iron and Steel Corporation

To solve potential scheduling problems in production after renewal of continuous casting process in Vanadium-extracting and Steel-making Plant of Panzhihua Iron and Steel Corporation (PISCO), how to model and simulate logistics system in steel-making processhas been discussed. A series of simulatingtests for logistics system in steel-making processhave been conducted based on inputs of presentsteel-making processof PISCO. In the tests, cases of regular schedule case and cases with repairing converter have also been regarded as essential simulation condition. It has been shown that three casters can not start at same time in order to ensure continuous hot metal supply for casters when three kinds of steel are made. It has also been shown that the simulation system for logistics system in steel-making processis valid and can be used for simulating logisticsin upcoming 100% continuous casting process of PISCO. The better schedule scheme of production and reasonable match of converter-caster in time and capacity can be achieved with the help of using simulation approach.     

Simulation method for multi-machine and multi-task crane scheduling in steelmaking plant

It is of great significance in steel complex to link production flow between work stations and control production rhythm by cranes. Crane scheduling is a multi-machine multi-task problem which limits temporal and spatial constraints and production plan. A simulation model based on evolution rules to solve temporal and spatial constraints is proposed. Its objective is to guarantee execution of production plan in steelmaking plant. And match between cranes and production task on working span is conducted to fulfill temporal constraints between multi-tasks and spatial constraints among multi-cranes. Simulation rules including task allocation, conflicts eliminating and task finishing are also proposed to dominate simulation process. This model avoids difficulties of theoretical calculation for crane scheduling problem. Offline test in a steelmaking plant shows that it is available to make a crane scheduling without conflicts between cranes and plans, which provides a guideline for production scheduling.     

Modeling and realizing of integrated batch planning for steelmaking-continuous casting and hot strip rolling

An integrated batch planning mathematical model based on multi-object optimization is proposed to solve the orderly and efficient flow of material between different working stations in iron and steel enterprises, where production technology constraints, material variations and coupling between steelmaking-continuous casting and hot rolling are analyzed first. According to the requirements of the hot rolling steel strip contracts, the integrated batch planning is divided into sub-plans of rolling plan, casting plan and furnace plan which are independent and coupling to each other, forming rolling plan and furnace plan simultaneously to influence casting plan. Heuristic method based on modified co-evolutionary algorithm is advanced to resolve this problem. The results of simulation and analysis in an iron and steel plant for strip steel production shows that it is feasible to provide effective guidance for integrated batch plan making.     

Dynamic Control Model for the Secondary Cooling of Slab Casting Based on Neural Networks

A dynamic control model for the secondary cooling of slab casting is presented to reduce the difference between the actual temperature and the goal surface temperature of slab. The model, which is based on the BP neural networks for forecasting the temperature and the fuzzy neural networks for dynamically controlling the water in the secondary cooling in the continuous casting, could timely adjust and allocate the water according to the speed and temperature of slab. A series of tests have been conducted based on inputs of the No. 2 slab caster in a steel plant. It has been shown that the model, which integrate the charateristics of water controlling problem in secondary cooling into the temperature status of slab during the cooling process, can control the water in secondary cooling efficiently and dynamically according to the situation of actual production.     

Advance in Mathematic Model of Solidification Heat Transfer Process in Continuous Casting

The mathematic model of solidification heat transfer process in continuous casting strand is useful for quantitatively analyzing heat transfer in continuous casting process, quality control and process control. The heat transfer in continuous cast strand in crystallizer and secondary cooling zone have been analyzed. The attention has been paid to basic logic and methodology in model building up. Typical methods determing solution condition and parameters for the model have been discussed. Some numerical methods at the present time for solving solidification heat transfer model, such as finite difference method, finite-element method and boundary element, have been investigated comparatively. In the future, working on solidification heat transfer model, which is more practical, and the integration of the control model will play an important role in the development of high efficiency continuous casting technology.     

Dynamics modeling and simulation for information diffusion in Internet of things

According to the perception and adaptive interactive features of information diffusion under the environment of Internet of things,with social physics ideas and vibration propagation concept, the dynamics variables of information diffusion in Internet of things and their corresponding effects on propagation behavior are defined and an information diffusion microscopic dynamics model is constructed based on the damped vibration equation．The Multi-Agent simulation technology and Netlogo simulation platform are employed to simulate the dynamic relationship between the microscopic individual propagation behaviors and the macroscopic overall operation mechanism. The rationality of the model is verified with a large number of numerical simulations．The nonlinear evolution rule of information diffusion system is analyzed based on the simulation results,and the corresponding strategies are proposed.     

Intelligent simulation of complex production systems including expert decision

Expert’s decision process plays an important role in production systems. To simulate complex production system including expert decision, an intelligent simulation strategy of complex production system based on interactive simulation and knowledge mining is proposed. The simulation principles and methodology are described. Key technologies of expert decision process simulation are studied in detail from the aspects of simulating algorithm and software programming. The simulation strategy is used and verified in a universal rail production line. Simulation results indicate that the intelligent simulation model can effectively describe complex production system including expert decision. It provides a new method for human machine cooperation and human decision making process study in production systems.     

Trust in Virtual Enterprise：Determinants and Mechanism

Trust is the most basic operation mechanism. From the embedded visual angle, the cooperation relation is considered as the inter-continuation.The trust relation in virtual enterprise is embedded in the network of social relation and will evolve dynamically. The interaction between partners, which is composed of information communion and learning, plays an important role in the creation mechanism of VE's trust . Firstly, this article starts with the time dimension of cooperation relation in VE, compartmentalizes the trust relation of VE as two parts: initial trust and continuous trust. Secondly, it argues that the prior experience of cooperation, reputation and commitment can affect the initial trust obviously, accordingly, the life cycle of VE, opportunism, interdependence and the distance of culture and geographic distribution can determine the generation and development of the continuous trust. Finally, it develops a dynamic process model based on information communion and learning, which perfects Nielsen's static conception model.     

Dynamical niche sets-based cooperativeevolutionary algorithm for job shop scheduling

Job shop scheduling is an important part of manufacturing process. Pre-mature, local optimal solution or low convergence rate of Genetic Algorithm may come across in solving scheduling problem in multi-Job shop. To avoid those unhealthy tendencies, this paper introduced the Dynamical Niche Sets-based Cooperative Evolutionary Algorithm model.In the Algorithm, Process-based chromosome encoding method was used; the crossover operator and mutation operator were designed to adjust operation sequences and choose process routes. The cooperative scheduling problem in multi-Job shop was solved using dynamical niche sets technology and multi-population cooperative evolution method. The Experiment result shows the proposed method has good advantages.     

AN A. C. LOAD FLOW ANALYSIS OF THE RELIABILITY EVALVATION OF COMPOSITE GENERATION AND TRANSMISSION SYSTEMS

An A. C. load flow analysis of the reliability evaluation of composite generation and transmission systems is presented on the basis of a fast outage simulation algorithm and an optimal model of active and reactive power adjustment after outage contingencies. The information of the first -level outage events is utilized for simulating higher -level outage events in the fast outage simulation algorithm ; the optimal model is satisfactory in speed and accuracy with the application of concentric relaxation and linear increment constraint on the comprehensive adjustment of active and reactive power. As an example. the IEEE Reliability Test System is tested and the results show that the method is accurate and well-matched in speed with the method studied by R. Bllinton, et al.     

An optimization method for the nozzle arrangement in secondary cooling zone of continuous casting

Based on the existing research on nozzle arrangement method in secondary cooling zone of continuous casting, the method of superposed water flow density is put forward to optimize the nozzle arrangement at casting direction and transverse section of slab according to the optimization principle. The two-dimension heat transfer model is established. The solidification morphology of cross-section at casting direction is simulated with consideration of the influence of water flow density inhomogeneity on solidification process at transversal section, and the temperature distribution of slab, solidification process, and quality of slab are compared between before and after optimization. The results indicate that the surface temperature of slab is dropped equably after optimization, and the casting blank is cooling uniformly in the water springing zone so as to ensure better quality of the casting blank.     

Solving Sequence of Ceramics in Roller Furnace by Genetic Algorithm

Furnace is the most important equipment in ceramics produce.In order to realize tactics of JIT,a optimal model of roller furnace is given out,and discuss the problem of solving E/T furnace shop scheduling by genetic algorithm.Contrast of genetic algorithm and EDD rule is carry out by computer simulation,the results indicate that the genetic algorithm is better and more practical.     

Modeling and Simulation for 440 t/h CFB Boiler Steam/Water System

Dynamic mathematical model,which is based on the character of power-plant boiler system,is established by the means of modularization. On the basis of dynamic mathematical models,simulation model of the object is created with the advanced continuous simulation language(ACSL).The validity of this model has been verified by the simulation experiments and analysis.The simulation model helps to evaluate the influences that the dynamic process in steam/water's side brings to the boiler's operation and have some directive significance to design method of boiler and optimize run.     

A Simulated Annealing Arithmetic Based on Uniform Design

Some ideas of uniform design in the test design are introduced into Simulated Annealing Arithmetic and a new method of design based on uniform design is discussed. The global optimal solutions of nonlinear multi-peak function can be found by this method. A series of uniformly distributed points are generated by the principle of the uniform design in variable design space. These points are regarded as a series of start points of the optimization model. The Simulated Annealing Arithmetic is chosen to compute and a series of local minimum values can be gained. Before compared with each other, the best value of all local minimum values can be found out, the value is thought as the global minimum in some degree. According to the method, a program is compiled and an example of design is implemented. The result of the example testifies that the method is feasible.     

Realization of Multi-task Scheduling in Linux Based IPC Measurement and Control System

Industrial Personal Computer(IPC) system generally works in long duration,and so a stable software is essential for an IPC system.Linux has a good deal advantages,such as,stability in use,open source code and free of charge, therefore an IPC measurement and control system has developed based on Linux. Multi-task scheduling is the critical part in system software.A simple method to realize multi-task scheduling in IPC measurement and control system based on Linux alarm clock mechanism is presented. Linux alarm clock mechanism is implemented by the cooperation of software timers and system call that is used to install and handle alarm clock.First, Linux process timers,soft interrupt signals, relevant system call are introduced,as well as applications of Linux alarm clock mechanism in multi-task scheduling. And then an example of the application in the IPC measurement and control system is given. The system has passed longtime run test,accomplished expected functions and shown well stability, so that practicability of the scheduling method has been authenticated.     

Design of ship-block production scheduling oriented knowledge navigation system

A knowledge map based knowledge navigation system model is established by combining the domain characteristics of production scheduling to counter the schedulers’ low-efficiency on account of confusion during production scheduling process. Key technology points,i.e. knowledge ontology building,semantic node integration,ontology based semantic relevance and the map implementation technique are analyzed. The knowledge navigation system is applied to ship-block production scheduling decision-making process. The method and technologies are verified in the ship-block scheduling process of a workshop in a shipbuilding factory.     

The Mathematical Model of Cooling and Heat Transfer for the Solidification of Thin Slab during Continuous Casting Process

In the established model, the cooling differences are considered between the surface of inner radius and that of outer radius, and in the transverse direction of thin slab. And the conception for the effective coefficient of spraying water in continuous casting is firstly put forward. According to different casting speeds and different cooling zones, different time step lengths are adopted. In this model the heat transfer differences are thought over among vertical and curved zones, wide and narrow surfaces an well as angular zone of mould. The method of the corrected equivalent specific heat is used to deal with latent heat. The influence of forced convection is considered on heat transfer. Therefore, the model has higher accuracy and is consistent with the practice.