Performance Simulation of EHE for 300MW CFB

With the development of circulating fluidized bed boiler(CFB),the study field of external heat exchanger(EHE) is greater in extent and degree.In order to research the working process of EHE,the model which deals with flow and heat transfer of EHE for 300MW CFB of Dong Fang Boiler Grou PCo.Ltd.is presented.Based on the cell modeling theory,the EHE is divided into several chamber by heating surfaces.The mass and energy conservation equations of each cell have been developed according to some reasonable assumption.The complete mathematical model has been compiled by Fortran and solved by classical Algorithm of Runge-Kutta.The static test and perturbation experiment of simulating model has been performed.The simulation results show that the model has been reached the steady state rapidly,the dynamic responses are reasonable and the modeling presented in the paper is reliable and appropriate.     

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。     

Mathematical Model of Control Cooling for Screw Rod After Rolling

The on line hot treatment can not only boost the strength but also gain lower cost. It is usually called tempcore which was developed greatly these years. The process of tempcor art is introduced and the core subject mathematical models is studied. According to the heating exchanging property of screw rod in cooling after rolling.Two mathematical models including beginning cooling model and cooling water amount model are obtained by analysing, deducing theoretically and simplifying mathematically. Its structure is simple and practiced .The parameter of model is obtained from measuring data of work site. It is able to suite the change of work site, so it can be used in practiced controlling.     

Numerical Simulation Analysis on Fire Facilities in an Underground Garage

The article uses the large Eddy simulation of Fire Dynamics Simulator（FDS）and parallel computing methods to numerical simulation on fire facilities in an underground garage. The main research is the effects of exhaust system and automatic sprinkler system in fire scene. Results show that: exhaust system can discharge high temperature and toxic gases, reduce smoke concentration and improve visibility effectively. Automatic water spray equipment mainly reduces heat release rate, and make smoke flow near the ceiling, which control the fire temperature very well. Combined with mechanical smoke exhaust system, it can better control the development of fire and effectively put out the initial fire. This study provides reference for fire safety design and assessment, which is of great significance to reduce casualties and property losses caused by the fire of underground garage.     

Numerical Simulation of Groundwater Flow and Quality

With societal development, wastes exist in industry, agriculture and human life. In particular, a large volume of urban industrial sewage is discharged and pesticides and fertilizers are widely used, leading to groundwater pollution in many areas. Based on a water quality model of hydrodynamic dispersion and the multi element balance (MEB) method, a general program for simulating groundwater flow and quality is carried out using the program VC++ for visual presentation. Using this program in a case study, the transportation mechanism of groundwater flow and quality is simulated numerically. The result indicates that the program is visual and can be manipulated well. It offers a point of reference for the reasonable exploitation, protection and utilization of the groundwater.     

A Fuzzy Controller with Simulating Human Intelligent Control and Its Simulation Analysis

In the intelligent control system with microprocessor controlling, the development of embedded software requires some simple and practical intelligent control algorithms. The algorithms can not only make the control system's performance good, but also meet the demands of real time control. Aim at the problem, it is presented that a fuzzy controller with simulating human intelligent control. The structure , control algorithms and the simulation results of the controller are given. The simulation and application show that the fuzzy controller with simulating human intelligent control has many advantages such as fast response, less overshoot, good robust. The design of the controller does not need the accuracy math model of controlled object.     

Numerical Simulation of Mechanical Behaviors of Articular Cartilages

Articular cartilage, which is composed with a solid phase of collagen fibers and proteoglycan and a pore fluid phase, can be depicted with two-phase porous medium model based on mixture theory. This paper analyzed the creep and stress relaxation responses of confined compression problems of articular cartilage with the developed finite element method. The obtained responses of velocities of both solid and fluid phases and the effective stresses of solid phase as well as the pore pressures during the creep and stress relaxation processes of articular cartilage tissues under confined compression can be used as a theoretical reference for man-made cartilage materials, and behave important significance for the research in bio-mechanical engineering area.     

Numerical Simulation of Frost Characteristic on Refrigeration System Evaporator

In order to analyze the running performance of refrigeration air conditioning system and confirm thaw periods in reason, frost process and change process of frost thickness of evaporator surface are studied. Based on basic theory and experiential formula of heat transfer process and mass transfer process, the math model of mass transfer of vapor on evaporator outside and growth process of frost are established. Aiming at a sort of finned-tube evaporator, frost process and change process of frost thickness are simulated numerically. The influence of environment parameters is analyzed.     

Numerical Simulation in Flow Field of CNG Vehicle Catalytic Converters

The steady flow in the catalytic converters of CNG was simulated. The gas can breakaway in the entering pipe and the flow of the gas can convergence well in the exhaust pipe. The flow distributing mainly depends on the flow capability of the expanding pipe. The pressure falls apparently in the carrier of catalytic converters. The noble metals in the center of the catalytic converters are consumed more quickly than the edge zone.     

Numerical Simulation on Drying Characteristics of a Combined Microwave-convection Process

Combined microwave-convection drying characteristics are investigated by numerical simulation. Combined microwave-convection drying has advantage of swift drying and sterilization. Based on qualitative analyses on the mechanism of combined microwave-convection drying, the differential equations are established and the numerical simulation method is described. The humidity, vapor pressure and temperature, along the radius in a spherical pill, are calculated by the numerical simulation during drying process. The calculation results show the relationship between humidity, vapor pressure, temperature and drying time, and that drying process is greatly influenced by input microwave power. The calculation results are good consistent with the experimental datum.     

A Numerical Simulation of Two-Dimension PoissonProcess and its Application in Simulation of an Uneven Road

An attempt is made to develop a numerical simulation rnodel of two-dimensionpoisson prcoess. Simulated and checked on computer,the road surface and spectrum of the roadwhich close to the ISO,The methed developed in this pa per is proved to be feasible and practicable.     

Numerical Simulation of Strata Movement Behavior in Deep Excavation

According to the complex conditions of deep excavation in Nantong mine, FLAC program are carried out for strata movement, ground pressure and surface displacement due to coal extraction. Based on the analysis of Nantong mine, the basic features of strata movement, the fundamental behavior of ground pressure and the related parameters of surface displacement are obtained. The results are of referential value for mining, supporting and preventing of surface displacement.     

沿海防护林网防风效应数值模拟研究

为研究沿海防护林网的防风效能,采用计算流体力学软件FLUENT对上海浦东新区的水杉林网周围的气流场分布进行了数值模拟。结果表明：水杉林网对气流有着明显的削弱作用,风速在林带前5 H左右处逐渐下降,在林带后出现回流现象,随后林带对气流的作用逐渐减弱,风速逐渐恢复。各林带的有效防护距离在10 H左右,因此,林网中林带间距设置在15 H左右比较合适。     

Numerical Simulation of HVAC in Vehicle Air Conditioning System

Through applying the theory of Computational Fluid Dynamics(CFD),this paper describes the numerical simulation of a typical HVAC in vehicle air conditioning system for improving on the structure of HVAC,shortening the time periods of product design and reducing the costs of design. By applying CFD to simulate designs and improve on the inconsepuential designs,it can make the symmetrical distributing of velocity and temperature of air in HVAC,obtain a proper value of velocity and reduce the yawp value.From the result of simulation,the numerical model has been optimized.It advances the capability of air-conditioning system.While applying CFD to the design of HVAC,it carry the purpose of shortening design the periods of HVAC and reducing the costs of empolderings and tests.     

Numerical Simulation of Berthing Velocity of the Ship

Based on the field data of berthing velocity for the ship (10000t-50000t), the berthing velocities have been numerically simulated by using Monte Carlo method in this paper. After statistical tests, it shows that the maximum values of the berthing velocity follow a Gumber distribution and the probability curves of failure for the means of maximum values are also obtained. The present results have been compared with the ones determined by specification of harbor engineering both at home and abroad.     

密集烤房内温度与气流分布数值模拟研究

提高烤房内温度及气流组织分布的均匀性,不仅可有效提高烟叶烘烤质量,而且可在一定程度上缩短烘烤时间,从而降低烘烤能耗。以密集型标准烤房为模拟研究对象,建立了装烟室内空气流动的k-ε两方程三维紊流模型。利用大型计算流体力学软件Fluent,对密集烤房内温度场及速度场进行了系统地数值模拟。分析了装烟室内温度及气流分布的均匀性,并获得了密集烤房合理的送风量。相关的数值模拟结果可为密集烤房结构、气流组织分布优化及循环风机选型提供参考。     

Optimization of Helix Intake Port Based on Numerical Simulation

With numerical simulation, an analysis is done on the three-dimension air flow in the helix intake port of a diesel engine. The anthors acquire the distribution of characteristic parameters of air in the port, such as velocity, pressure, turbulence kinetic energy, as well as the flow coefficient and rotate moment around the erect axes at the outlet. The results of simulation indicate that the negotiability of the port is very good while the ability of forming eddy can be enhanced, so several improve measures have been put forward. Comparing with simulation results of these measures, it finds out that the method of combining increase the distance between the definition curve of volute cavity and central line of valve protruding support as well as increase the eddy shell angle can obviously enhance the ability of forming eddy, which is an efficient and rational method.