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.     

Real-time Supervisory Control System of Steam-injection Boiler

To guarantee the safety and reliability of steam-injection boiler, the real-time supervisory control system of steam-injection boiler is developed. This system consists of host computer and slave computer two levels system. The run parameters and run status of steam boiler are automatic supervisory with the host computer. The important parameters acquisition and manual adjustment to run parameters of steam boiler are accomplished by the slave computer. The practice proves the validity of this system.     

基于PLC的锅炉补水泵控制系统研究

设计了一套水暖锅炉自动调温系统应用于农业生产,主要部件包括主机、辅机、控制系统和水暖管道装置等。基于PLC的锅炉补水泵控制系统能够对整个锅炉的运行状况进行监测、报警、控制,保证锅炉正常、可靠地运行。该设计克服了以往养殖水暖锅炉中存在的缺陷,可以保证锅炉补水泵控制系统稳定可靠工作。     

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.     

Temperature Control of High Temperature Melt Viscosity Test Instrument

The construction and function of high temperature melt viscosity test instrument are introduced in this paper. And the character of temperature control system is given. In order to improve dynamic and static performance of the temperature control system, a new method is proposed which combines threshold control with adaptive fuzzy PID control. While the current temperature of the heating furnace is much lower than the given temperature, threshold control works in order to protect system and improve dynamic performance. When the current temperature is close to the given value, adaptive fuzzy PID control works to improve static performance. At last, simulation and experiment results validate the proposed control method.     

南京局地气候系统反演建模研究

为了研究南京局地气候动力系统的演变,利用无量纲处理后的南京站1951—2013年逐年云量、气温和降水资料,采用反演建模方法,构建了1951—2013年南京局地气候模型,并对南京局地气候模型的各项系数进行了初步的物理解释。结果发现,南京局地气候模型中云量指数的变化与云量指数、降水指数和降水指数的二次项有关;气温指数的变化与气温指数、云量指数、降水指数和气温指数的二次项有关;降水指数的变化与降水指数、云量指数和降水指数的二次项有关。以每30年的数据反演局地气候模型,发现非线性部分系数呈减小趋势,其中利用1961—1990年和1962—1991年数据的反演结果中,云量和降水变化方程中降水二次项系数都发生了突变。线性部分在气候态附近保持稳定。     

中式生产线锅炉的选型与工程监理的管理技术

锅炉设备在食品工业中的应用范围很广,很多的食品企业都应用锅炉的蒸汽进行加热操作。介绍了中小型食品生产线对锅炉设备的选型标准及安装形式,以及锅炉蒸汽管路与食品生产线成套设备安装的工程监理,以期为在实际生产操作中选择合适的锅炉设备和降低安装成本提供参考。     

Numerical Value Stimulation and Run Experiment of Burning Device in a Boiler

This article analyzes what causes the lower main steam temperature of 1# boiler in the PZH-Steel Plant, then designs reconstructive project of spout of burning device which will be up and diameter of tangent round which will be decreased. At the same time, it is analyzed through numerical value stimulation and usual thermal calculation of boiler, and the result of calculation is used to reconstruct the actual boiler. The result of reconstructive run experiment shows that numerical value stimulation was correct, and attains anticipated object.     

Defects detection in the inner surface of pipes based on inverse heat conduction problem

It is a typical ill posed inverse heat conduction problem to estimate the geometry boundary of the inner surface of pipe by the temperature of outer surface. With the establishment of a two dimensional steady model for pipe with irregular inner surface, the inverse problem is transformed into a direct problem and an optimization problem. Based on the temperature at the outer surface obtained from the infrared thermography and the variation of the object function, the conjugate gradient method (CGM) is introduced into the geometry problem. With the numerical analysis of three typical defects, the effects of the measurement errors, choice of the initial value, boundary conditions and number of discrete temperature points are discussed and the proposed methodology is approved.     

Saturation and Parameter Variation Influence Precision of Observer

The authors analyze the influence in vector controlled induction machine caused by parameter variation and main flux saturation affects speed estimation of adaptive state observer. According to simulation of the modified scheme with saturated induction motor model, it is proved that when the vector control scheme operates in field weakening region, the main flux saturation will obviously influence precision of speed observer and bring great error of speed estimation. Thereby, the main flux saturation should be compensated to improve performance of the vector control system.     

Two Types Modules for the Boiler Attached to 330 MW Unit

Boiler is an important facility in power plant , the safety and economy of unit is affected by it. Studying the dynamic of boiler can improve the knowledge about boiler , which is important for. Features of MMS are introduced based on MMS simulation setting, and the real time capable module and non real time capable module are compared from principle. Real time capable dynamic model of boiler and non real time capable dynamic model of boiler of 330 MW unit are established . The experimental results show that the dynamic process of two type model accords with the mechanism of the object , at the same time, the validity of real time capable module is discussed .     

Simulation Research of Control Parameters in Induction Motor Vector Control System

In order to obtain the effect rules of control parameters of speed regulator on performance indexes of induction vector-controlled system and the setting rules of control parameters of speed regulator,according to rotor flux oriented control principle,a vector control model of induction motor is established and simulated with the software of Matlab/Simulink.This vector control system is proved that it possesses good static and dynamic performance.This paper analyzes the effect of control parameters' variations of speed regulator on performance indexes and gives simulation results.     

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.     

Modeling and Simulation Analysis of the Electromechanical Coupling Facts about Precision Transmission System

Electro-mechanical coupling facts about transmission system influence dynamic characteristic and response characteristic of servo system. The coupling factors of precision transmission system are put forward, and the modelling methods of electro-mechanical system are analyzed. Based on the large-scale precise horizontal machining center, the dynamic chart of servo feed system is gained through analyzing mathematical model of the taehes, and the influence on transmission stiffness and transmission error is simulated in precision transmission system. Through changing parameters in servo feed system, the influence on dynamic characteristic and response characteristic is analyzed, so it provides a mathematical model for parameter optimization.     

基于PID算法对热风炉热风温度控制及仿真分析

在农作物金银花干燥期间,为了满足干燥热风的温度和风速的稳定性要求,针对热风炉出风口热风温度与设定的温度值滞后和稳定性差等问题,设计了一套以单片机STM32作为核心处理器和模糊自适PID算法作为参数控制器的控制系统,实现模糊自适PID算法对参数进行调整。利用Matlab语言建立模型,对整套控制系统进行仿真分析。结果表明:出风口热风温度的稳定性能达到95%以上,该研究方法提高控制系统的性能,有利于农作物干燥的质量和效率。     

Petri网逆网在主轴故障诊断中的应用

比较了成熟期27个梨品种的果胶含量、半乳糖醛酸含量、果肉硬度和可溶性固形物含量,并分析果胶含量与果实品质特性的相关性。结果表明,不同梨品种间的果肉硬度、可溶性固形物、果胶、半乳糖醛酸含量4个指标的差异性都达到极显著水平(P0.01),果肉硬度均值为2.76 kg·cm-2,F值为47.03;半乳糖醛酸含量为0.64%~1.73%,F值为89.24,品种间差异最大;可溶性固形物含量为9.41%~15.19%,F值为17.66,品种间差异最小;果胶含量为0.23%~1.02%,与可溶性固形物和半乳糖醛酸含量呈极显著正相关(P0.01),Pearson相关系数分别为0.618和0.680。     

A SELF-TUNING CONTROL FOR A PARALLEL AC/DC POWER SYSTEM

Based on a non-linear system model, an adaptive control methodology is presented for a parallel AC/DC power system by means of on-line recursive parameter identifications. Taking the advantage of rapid power regulatiing ability of the DC power system and combining with the generalized minimum variance self-tuning control principles, the dynamic qualities of the controlled system has been greatly improved. Using SISO form makes the control system very simple to implement. Through the design, simulation and analysis of the self-tuning control system for a practical example, it shows that the self-tuning control strategy is very promising for AC/DC power systems.     

The design of torque dynamic sliding mode controller in permanent magnet synchronous generator for wind turbine

Permanent magnet synchronous generator for wind turbine is a multivariable nonlinear system with strong coupling. Considering the influence of the volatile parameters of the generator on the performance of vector control, the torque dynamic sliding-mode control strategy is further studied. The proposed first order dynamic sliding-mode control strategy reduces the chattering by using a new switch function constituted with derivative element. With the dynamic sliding-mode controller in the power outer loop, the PMSG vector control system shows excellent robustness and insensitivity to the parameters and disturbance, which is confirmed by simulation.     

Simulation Modeling and Simulation Analysis for the Boiler Attached to 360 MW Unit

Using modular simulation technique,a mathematical model for the combustion and air/gas system of the W shape flame boiler is presented.The experimental resulats show that.The dynamic process accords with the mechanism process of the object.     

MATHEMATICAL MODEL AND DIGITAL SIMULATION FOR A REGENERATIVE HEATING SYSTEMS OF 200MW REHEATING STEAM TURBINE

Based on the physical processes of regenerative heating systems, the mathematical models of regenerative system,reheat system and steam turbine for a 200MW reheating steam turbine are presented, and the digital simulation of them on IBM-PC is also provided in this paper. The present work is a part of the study of the dynamic characteristics of all power systems. The mathematical model is expressed into state space form ,and its matrix is standardized to avoid the repeatation of establishing the models of heat exchangers.