Application of Mathematical Experimentation with Computer in Hydraulic Control

Computer mathematical experimentation technology is applied in pressure hydraulic .The non-linear mathematical model of stage mechanical control system is established by the application of computer mathematical software Maple. The computational results agree with experimental data, and precision is satisfied. The mathematical model is the first apply in the control system of stage mechanical elevator. The method has a wide application in computer auxiliary and simulation of mechanical control system.     

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.     

Dynaical Mathematical Model of String

In the process of oil drilling, drilling string and rock bit are main drilling tools. The fact of their failure would cause serious accidents. To solve this problem, the vibration law of string should be found. The longitudinal vibration model, torsional model and lateral vibration model are founded simultaneity. Many methods are used to build up this model, including finite element technique, numerical technique and computer simulation. The dynamic model reveals the dynamic action of string, it is instructive to design new rock bit and study drilling mechanics.     

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.     

滤棒增塑剂的影响和控制域研究

分别进行了滤棒增塑剂梯度施加研究和生产条件下的控制域研究,研究结果表明,增塑剂设定施加量与实际施加量成线性相关关系;增塑剂施加量与滤棒硬度呈显著正相关关系,并对滤棒圆周和硬度标偏有一定影响,但对滤棒吸阻无显著影响;正常生产条件下,由于受诸多条件影响,增塑剂施加量与滤棒硬度相关性下降,但通过数据分组,可以确定其相关关系,从而选择增塑剂施加量的控制域。     

Numerical Simulation and Analysis of Control Rod Dropping of Qingshan 300 MW Nuclear Reaction

This paper provides a theoretic basis to analyze the mechanism of control rod dropping and a solution method to solve the process of dropping. The authors analyze the effect of different forces acting on the control rod in detail. A mathematical model is built and a program is written to solve the process of downward motion. Finally, the model and relative coefficients of the model are modified according to the experimental data. The modified model can well simulate the process of dropping of the control rod, which gives a powerful proof to the accuracy of the model.     

Dynamic Control Arithmetic and Modeling of Secondary Cooling System for ROKOP Billet Continuous Casting

A dynamic control arithmetic and mathematic model of secondary cooling system for ROKOP billet concasting has been developed in view of the changes of casting speed during concasting process and the high fluctuation of surface temperature due to the use of static control method. By means of computer simulation and by comparison between static and dynamic control method, it proves that the latter one is more adaptive to the changes of casting speed, which leads to lower fluctuation of surface temperature.     

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.     

预测木薯茎叶生物量的数学模型

为了构建预测木薯茎叶生物量的数学模型,调查了5个木薯品种茎秆的基部、中部、上部茎粗及茎秆长度和各个分枝的基部粗度、长度等形态学指标,并将生物量分为茎秆和分枝两部分,分别探讨这两部分生物量与相关形态指标的关系。通过多种模型的反复拟合比较,结果以主茎复合幂函数与分枝集合函数的统合方程的拟合效果较好,均方根误差RMSE为104.2,相关系数r为0.9110,拟合优度较高。并且本模型的拟合效果明显优于前人提出的预测木薯茎叶生物量的数学模型。     

Macroscopic and Microscopic Coupling Mathematical Model for Solidification Process of Twin-roll Thin Strip

A macroscopic and microscopic coupling mathematical model for solidification process of twin-roll thin strip is developed. In the model, the latent heat is treated by the enthalpy method, and the grid and node are divided by assumed streamline boundary. The heterogeneous nucleation and the columnar-equiaxed transform(CET)model are introduced, together with the revison of the dendrite growth dynamic model of KGT. With the help of solid fraction, the coupling of the macro/micro aspects is realized by using different grid-sizes and time-steps, macro and micro, together with the columnar dendrite front tracing. The columnar dendrite arm spacing and deflection angle calculated by proposed model are in agreement with the experimental ones. Therefore, the model is proved to be reliable, and it can be used to predict the effects of the processing parameters on the solidification structure of twin-roll thin strips.     

Establishing and Application of the Mathematical Model of the Impulse Electroflotation Reacting Tank

The properties of the Impulse electroflotation equipment are introduced briefly ,and the factors that influence the treatment effect of Impulse electroflotation are analyzed. The mathematical model of the Impulse electroflotation reacting tank which determines the height, volume and treatment capability of Impulse electroflotation is provided on the base of the basic equations of electroflotation. A calculate software for the design of Impulse electroflotation reacting tank is developed and the source code is given.     

棉花群体干物质生产与分配的数学模型研究

在１９９１～１９９３年棉花高产优质与生态环境因子关系研究的基础上，利用作物生长模拟分析的方法和大量试验资料及相关的气象资料，建立了棉花群体干物质生产与分配的数学模型。该模型包括：叶面积动态，光合生产，干物质积累和分配子模型。所建模型经检验，具有较好的模拟性能，可用于指导棉花生产。     

乳品冷却工艺中自动控制氨用满液式蒸发器的应用

根据乳品生产过程中乳品快速冷却的需要和乳品冷水冷却系统的工作原理,在乳品冷却工艺中应用先进的电子测控技术和控制阀件自动控制氨制冷系统满液式壳管蒸发器,可快速精确地调节冷水温度,使氨系统安全可靠地运行。     

南疆沙壤土地面灌溉高产棉田施肥灌水数学模型研究

在南疆沙壤土棉田,设置了3个处理因子(施氮、施磷和灌水),每个因子依施用量设4个水平,开展了水肥耦合效应对棉花产量影响的田闻试验研究.试验结果表明,棉花产量对氮肥、磷肥、水的依赖程度顺序是:氮肥＞磷肥＞水,并建立了地面灌溉条件下高产棉田水肥施用的多元回归数学施肥模型:y=-677.8075+0.5889 xN+11.1...     

Mathematical Model of Flow Process in 40t/h Pyroflow Circulating Fluidized Bed Boiler

A mathematical model is presented to describe the fluiddynamics processes for the combustion system of 410t/h Pyroflow CFB boiler.A core annulus structure with solid dispersion from core to annulus is considered,and the influence of coal particles fragmentation,attrition and broad size distribution of feeding coal and bed inventory on hydrodynamics is specially taken into account.The simulation results show that the CFB boiler has good hydrodnamic characteristics and high hot cyclone efficiency.     

Mathematical Model of Oxygen Blast Furnace with Preheating Gas Injection into Upper Shaft

An One-dimensional mathematical model,based on oxygen blast furnace with preheating gas injection into upper shaft,has been developed to describe the variation of innerdiameter of blast furnace,13 chemical reactions,the heat losses through the furnace wall,the heatexchange and pressure losses between gas phase and solid phase.The characters of oxygen blastfurnace are discussed,The simulated results indicate that the tem perature of burden in creasesthroughout the upper shaft with the incrcasement of the flow and the temperature of preheating gasinjected,and that the effect of the heating-up of burden is not so large when the com positions ofpreheatin8 gas injeetion are changed.The model is contributed to obtain a deeper understanding ofthe oxygen blast furnace process.     

Mathematical Model of Selective Catalytic Reaction of Nox in Reactor and Its Simulation

As the domestic technology of selective catalytic reduction(SCR) has not been mature.A assembled-parameter dynamic mathematical model is established for the primary chemistry reaction process in SCR reactor.The mass balance equation of the NH3 adsorption-desorption on the catalyzer surface and six gas components,and total energy balance equation in SCR reactor are set up respectively.A dynamic simulation model has developed by using MATLAB simulation tool.The steady calculation for model is carried on.Based on the established dynamic simulation model,two dynamic simulation experiments have been done,which include the simulation experiment of step disturbance about NOx concentration and temperature.The simulation results current is correctl.The analyzed results indicate that the established dynamic mathematical model for SCR reactor is credible,and prove that the simulation model is practical.