多媒体高温炉窑温度分析系统

本文提供了一种多媒体高温炉窑温度分析技术,介绍了基于该技术建立的高温炉窑温度分析系统,该系统可以提供高温炉窑的实时窑内温度分布图和其它工况参量。本文根据该系统在水泥回转窑中的应用结果对系统性能进行了分析。     

石灰石窑温度检测系统研究

稳定的温度是石灰石回转窑生产过程中的一个非常重要的参数。它对提升产品质量、提高产量、降低能源损耗等都起着关键的作用。对窑内进行温度控制首先必须精确地检测窑内温度,文中设计了回转窑滑环式测温系统,取得了较好的效果,解决了回转窑高温检测困难大等问题。     

多自由度回转窑滑环供电装置的设计

在对工业铝渣进行烘烤破碎时,要通过窑上风机及窑内加热体控制回转窑窑内温度。回转窑滑环供电装置是供电系统中的关键装置。文中叙述了目前企业中回转窑滑环装置的使用现状,分析了各种滑环供电装置存在的问题。根据现场技术需求,设计了一套多自由度回转窑滑环供电装置。现场使用过程表明,该装置可以适应回转窑在高温工作过程中的轴向和径向变形,可以为回转窑窑体可靠安全地供电。     

含钒页岩焙烧用回转窑结构优化数值模拟研究

建立含钒页岩焙烧用回转窑的稳态传热数学模型,运用Fluent软件模拟计算等径回转窑内流场和温度分布。在合适位置扩大等径回转窑尾内径,对其窑内流场和温度分布进行模拟计算。在此基础上,分析变径大小和变径位置对窑内温度的影响,得到最优的变径回转窑;然后分析比较等径型与变径型回转窑温度分布特征。结果表明:在相同的工艺条件下,在合适位置变径的变径回转窑焙烧段长度比等径型回转窑的长,有利于提高含钒页岩中各低价态钒的氧化率。     

基于多重分形的水泥回转窑工况识别研究

鉴于多重分形理论在定量描述复杂系统非线性运行规律方面具有的独特优势,将多重分形理论引入到工况特征识别研究中来,确认了水泥回转窑窑电流信号的多重分形特性.在此基础上,研究了窑电流多重分形谱参数随工况变化的情况,发现多重分形谱参数的变化趋势与回转窑内工况状态的变化趋势之间具有较强的关联性,进而提出了基于多重分形谱参数进行水泥回转窑异常工况特征提取的新方法,为水泥生产过程中工况状态的在线监控和预报提供了有力支持.     

基于无线技术的回转窑温度监测系统

分析国内外当前回转窑温度监测系统的特点及其局限性,提出了一种基于无线技术和太阳能技术的回转窑温度监测系统解决方案。该方案以S型热电偶作为测温元件,用太阳能作为供电电源,通过无线传输温度信号,摆脱了电源线路和通信线路的束缚,成功地实现了对回转窑窑筒体温度的接触式测量。实践证明：基于本方案设计的回转窑温度监测系统测量精度高、成本低。     

回转窑烧成带温度模糊控制器的设计及仿真

介绍了模糊控制技术在水泥回转窑烧成带温度控制中的应用,利用MATLAB软件对水泥回转窑的模糊控制器进行了计算机仿真,并与传统PID控制器的仿真效果进行了对比,仿真结果表明,该控制方法无超调、控制精度高、稳定性好,能够实现水泥回转窑烧成带温度的仿真控制。其控制效果明显优于传统的PID控制。     

氧化铝回转窑模糊监控系统的设计与应用

在对氧化铝回转窑进行热工分析的基础上,以某氧化铝厂回转窑为研究对象,应用模糊控制理论,设计氧化铝回转窑模糊监控系统,并利用热工分析与智能控制系统软件,在数据通讯的基础上完成在线监控.结果表明,采用模糊监控系统后,窑内熟料温度稳定,模糊监控系统优化了烧结制度,实现了下煤量自动调节,与人工控制的回转窑相比,其热工状况稳定,熟料质量、产量均提高,达到了增产降耗的目的,提高了现代化管理水平.     

基于炼镁回转窑煤粉制备与喷烧系统工艺研究

针对炼镁回转窑煤粉制备与喷烧系统,研究一种适合炼镁回转窑热工制度、适度提高窑内温度、拉长高温带长度、提高锻白质量和产量的工艺,突破传统炼镁业煤粉制备与喷烧系统工艺的弊端和局限性,实现炼镁回转窑煤粉制备与喷烧系统从制粉到喷烧的高效运行。     

水泥回转窑多点温度监测系统设计

水泥回转窑内温度测量是关系到水泥质量的关键问题.文中提出了利用AVR单片机控制光源,通过位移-光强度型光纤温度传感器的调制,带有温度信息的光信号耦合到LOG114芯片进行光电转换及放大,输出信号再由AVR单片机进行A/D转换,经数据分析,得到回转窑内部温度分布的方法.系统具有易安装、多点化、精度高、体积小等特点.     

煤粉定量转子秤的开发和应用

煤粉定量转子秤是能满足现代水泥窑燃烧器特殊要求的一种新型的煤粉测重喂料装置。本文介绍了转子秤的性能、结构原理、应用以及与传统煤粉喂料机的比较。     

基于模糊神经网络的梭式窑自适应控制系统应用研究

针对梭式窑温度控制过程存在非线性、时变性和不确定性等情况,设计了基于模糊神经网络的自适应控制(MRAC)系统并运用于梭式窑中,即采用RBF径向基网络作为梭式窑温度对象的辨识网络,它产生的Jacobin信息与控制误差一起提供给模糊神经网络控制器作为其学习信号,经过MATLAB仿真调整初始参数。最后运用VC++软件结合数据采集卡对燃气梭式窑进行控制。该控制系统能辨识出梭式窑时变性、非线性、长滞后性的对象特性,实时修正控制器参数,以适应对象特性的变化,在实际应用中取得了良好的控制效果。     

基于卡尔曼滤波器的数据融合方法在高温炉检测系统中的应用

本文将数据融合方法引入高温炉窑温度检测系统,充分利用现有检测系统的能力,在不增加任何设备的情况下,提高检测精度,实践证明该方法理论简单、易于实现、精度高,它适用于各种高温炉窑温度检测系统。     

The stress relaxation of cement clinkers under high temperature

The energy consumption of crushing is directly affected by the mechanical properties of cement materials. This research provides a theoretical proof for the mechanism of the stress relaxation of cement clinkers under high temperature. Compression stress relaxation under various high temperatures is discussed using a specially developed load cell, which can measure stress and displacement under high temperatures inside an autoclave. The cell shows that stress relaxation dramatically increases and that the remaining stress rapidly decreases with an increase in temperature. Mechanical experiments are conducted under various temperatures during the cooling process to study the changes in the grinding resistance of the cement clinker with temperature. The effects of high temperature on the load-displacement curve, compressive strength, and elastic modulus of cement clinkers are systematically studied. Results show that the hardening phenomenon of the clinker becomes apparent with a decrease in temperature and that post-peak behaviors manifest characteristics of the transformation from plasticity to brittleness. The elastic modulus and compressive strength of cement clinkers increase with a decrease in temperature. The elastic modulus increases greatly when the temperature is lower than 1000 °C. The compressive strength of clinkers increases by 73.4% when the temperature drops from 1100 to 800 °C.     

改善大掺量粉煤灰水泥石抗碳化性能的试验

采取高温养护、粉煤灰磨细和水泥石内部补足碱3种方法,对大掺量粉煤灰水泥石的抗碳化性能进行改善,利用碳酸盐定量分析法对改善后水泥石的抗碳化性能进行测试,结果表明：高温养护和粉煤灰的磨细对大掺量粉煤灰水泥石的抗碳化性能有较好的改善效果;补足碱对大掺量粉煤灰水泥石抗碳化性能的改善作用不大。     

基于模糊预测控制的回转窑温度控制

介绍了模糊预测控制技术在水泥回转窑温度控制中的应用。水泥生产的关键环节在于水泥回转窑,其中最重要的就是对回转窑温度的控制。针对热工对象存在的大惯性、大迟延问题,运用T-S模糊模型的离线辨识算法对复杂的热工对象建模,得到了回转窑温度控制系统的线性化模型。     

Apparatus for monitoring the resistivity of the hydration of cement cured at high temperature

A resistivity apparatus was developed to investigate the early hydration processes of cementitious materials cured at elevated temperatures. The apparatus consists of a temperature control system, resistivity measurement system, and automatic data acquisition system. The temperature control of the resistivity apparatus was ±0.5°C. Three parallel measurements varied by approximately 5%, which shows that the apparatus was reliable and reproducible. By monitoring the electrical resistivity of fresh cement, the hydration process was characterized. The developed device may provide valuable insights into the mechanisms of cement hydration at high curing temperatures. In addition, increased curing temperature accelerates the setting process and strength development of the cement. However, high temperature has negative effects on compressive strength of the material.     

Temperature and ageing condition effects on the characterization of acrylic bone cement

This study investigates the effect of the environmental temperature and ageing condition on the characterization of acrylic bone cement. The tests were performed according to ISO 5833. The testing parameters were allowed to vary within the limits defined by the standard, in order to assess their effect on the results of the test. In certain cases the tests were also performed under conditions which the standard does not provide for but which are likely to occur clinically. This investigation showed that the cement behaviour may also change in the temperature range specified in the standard. Therefore, it is deemed appropriate to correlate the curing parameters of the bone cement to the environmental temperature, performing the test at different temperatures. In this way the effect of temperature on the duration of the phases in the cement curing could be assessed. The resultant graphical representation of the effect of temperature on the duration of the phases in cement curing has direct clinical relevance. Furthermore, this study showed that the ageing conditions of the mechanically tested specimens affected the results. Hence, it is deemed advisable to modify the ageing conditions of the specimens, fixing them closer to the in vivo conditions.     

篦冷机的渗流传热模型与数值模拟

针对水泥篦冷机内熟料堆积体的多孔介质特性,应用非热平衡理论并结合Forchheimer-Brinkman-Darcy扩展模型,建立篦冷机的渗流换热模型。采用此模型对篦冷机内水泥熟料的冷却过程进行数值模拟,获得了不同供风风速、不同篦速下的气体和熟料层温度的变化规律。研究结果表明,所建模型可以较为准确地反映水泥熟料堆积体的冷却过程;供风风速的增加虽有利于熟料颗粒的冷却,但会降低回收风的温度,不利于热量的回收,合理的供风风速区间为1.5～2.0 m/s;在产量不变的情况下,增加篦速可强化熟料的前端骤冷效果,有利于形成高品质熟料,但是过高的篦速会使篦冷机前端的气体温度偏低,不利于水泥熟料的烧成;在料层厚度不变的情况下,增加篦速,回收风温与出料温度升高,但篦速过高时出料温度偏高;综合考虑产量不变与厚度不变这两种情况下篦速对熟料冷却过程的影响,得出合理的篦速区间为0.006～0.008 m/s。