热风管道的保温与节能

1.前言 最大限度地回收加热炉出炉废气带走的热量,再使其返回炉内,是加热炉节约能源、降低单耗的重要措施之一。为此,除尽量保存出炉废气余热、采用高效率的空气预热器之外,对空气预热器出口至烧嘴之间的热风金属管道进行包扎保温,尽量减少其表面散热损失,也是一个重要方面。 本文以理论计算为依据,计算了不同管径、不同风温、管内空气不同流速等条件下,热风管道不保温、采用不同保温材料以及不同保温层厚度与其表面散热损失之间的关系,可对热风管道的合理设施和包扎保温提供一定的科学依据。     

直埋敷设蒸汽管道的保温

本文探讨和介绍了蒸汽直埋敷设管道的保温及保温层厚度计算方法。     

顶燃式热风炉热风管道长寿设计浅谈

对顶燃式热风炉热风管道的破损机理进行了分析,就热风管道补偿的设计,管道砖衬结构的设计和耐材种类的选择提出了一些看法,并对热风管道砌筑和烘烤提出了一些建议,以确保热风管道安全使用及长寿。     

硅铁矿热炉余热发电烟气管道保温结构分析

针对硅铁矿热炉余热发电锅炉进口烟气管道常用的几种保温结构,对不同保温结构对应的保温层厚度及烟气温降进行了计算,分析了各种保温结构的优缺点,为硅铁矿热炉余热发电烟气管道保温结构的选取提供借鉴和参考。同时,也可供其他行业余热发电类似参数烟气管道的保温结构参考。     

高炉热风管道系统膨胀缝设置

针对传统高炉热风管道系统膨胀缝留设过大、不合理的问题,分析了热风管道工作层砖和轻质隔热砖的膨胀和收缩性质,提出了合理的热风管道膨胀缝设置方法,在生产实践中应用效果良好,对热风管道砌筑具有指导意义。     

昆钢2500m^3高炉热风管道温度异常分析及处理

本文对昆钢2500 m^3高炉热风管道发生温度异常状况的处理实践进行了总结和分析。针对昆钢2500 m^3高炉在开炉6年多后出现的热风管道部分区域温度升高的情况进行原因分析,并根据情况对温度异常部位进行浇注处理,取得了较好的效果,有效抑制了温度的进一步升高,避免了热风管道烧穿恶性事故的发生,为高炉稳定生产奠定了基础。     

PA-80浇注料在高炉热风弯管上的应用

介绍了高炉热风弯管内保温层采用捣制PA－80浇注料代替其它耐火材料后的使用效果,经过理论分析和实践应用,认为这种耐火材料能在高炉热风弯管上推广应用。     

PA—80浇注料在高炉热风弯管上的应用

介绍了高炉热风弯管内保温层采用捣制ＰＡ－８０浇注料代替其它耐火材料后的使用效果，经过理论分析和实践应用，认为这种耐火材料能在高炉热风弯管上推广应用。     

太钢三高炉热风炉易地大修工程热风管道设计的改进

本文结合对太钢三高炉热风管线设计,介绍了波纹补偿器及拉紧装置在热风管道的运用,热风管道内衬耐火材料的选择,热风管道系统采取这些措施后,可以消除因管道受热膨胀、热风支管法兰错位等造成的漏风现象,保证热风管道系统完全可靠的运行。     

高风温热风炉热点问题讨论

本文分析了改变炉箅子结构的方法来增强炉箅子强度,从而使热风炉烟气温度提高到550℃成为可能,还分析了热风主管堵头盲板力、热风管道三通盲板力、联络管弯头盲板力对热风管道的影响,并提出了相应的改进措施。     

Optimum Design of Microirrigation Systems in Sloping Lands

When an area to be irrigated has a high slope gradient in the manifold line direction, an option is to use a tapered pipeline to economize on pipe costs and to keep pressure head variations within desired limits. The objective of this paper is to develop a linear optimization model to design a microirrigation system with tapered, downhill manifold lines, minimizing the equivalent annual cost of the hydraulic network and the annual pumping cost, and maximizing the emission uniformity previously established to the subunit. The input data are irrigation system layout, cost of all hydraulic network components, and electricity price. The output data are equivalent annual cost, pipeline diameter in each line of the system, pressure head in each node, and total operating pressure head. To illustrate its capability, the model is applied in a citrus orchard in S?o Paulo State, Brazil, considering slopes of 3, 6, and 9%. The model proved to be efficient in the design of the irrigation system in terms of the emission uniformity desired.     

高风温热风炉热风管道系统合理结构研究

目前,我国高炉热风炉热风管道结构存在一定的不合理性,限制了热风温度的进一步提高.从确定临界热绝缘直径、采用波纹补偿器和应用耐火材料三方面,论述了获得合理和稳定的热风管道结构的措施.     

Choosing Pipe Diameter to Maximize Inline Storage Volume

For a wastewater collection system, the maximum volume that can be attained with an inline storage pipe is shown to occur when the pipe diameter is chosen to be 2/3 of the thickness of soil profile available for burial of the storage pipe, irrespective of pipeline slope.     

Numerical Modeling of Local Scour below a Piggyback Pipeline in Currents

Local scour below a piggyback pipeline in steady currents is investigated numerically. A piggyback pipeline comprises two pipelines that are arranged in the so-called piggyback configuration with the small pipeline being located directly above the large pipeline. The Reynolds-averaged Navier–Stokes equations and the transport equation for suspended sediment concentration are solved using a finite element method. The bed scour profile is determined through solving sediment mass conservation equation. The numerical model is validated against experimental data available in literature on scour below a single pipeline. Computations are carried out for the diameter ratio [the small pipe diameter (d) to the larger one (D)] of 0.2 and the gap (G, between the two pipelines) to the large diameter ratio G/D ranging from 0.0 to 0.5. It is found that the flow and the scour profiles are influenced significantly by the gap ratio.     

Optimal Design of Pressurized Irrigation Subunit

A linear programming (LP) model is presented for optimal design of the pressurized irrigation system subunit. The objective function of the LP is to minimize the equivalent annual fixed cost of pipe network of the irrigation system and its annual operating energy cost. The hydraulic characteristics in the irrigation subunit are ensured by using the length, energy conservation, and pressure head constraints. The input data are the system layout, segment-wise cost and hydraulic gradients in all the alternative pipe diameters, and energy cost per unit head of pumping water through the pipeline network. The output data are: segment-wise lengths of different diameters, operating inlet pressure head, and equivalent annual cost of the pipeline network. The explicit optimal design is demonstrated with design examples on lateral and submain or manifold of pressurized irrigation systems. The effect of the equations for friction head loss calculation on optimization procedure is investigated through the design example for microirrigation manifold. The performance evaluation of the proposed model in comparison with the analytical methods, graphical methods, numerical solutions, and dynamic programming optimization model reveals the good performance of the proposed model. The verification of operating inlet pressure head obtained by the proposed model with accurate numerical step-by-step method suggested that it is mostly accurate.     

高压水除鳞系统管路预充水方式的选择

热轧生产线配套的高压水除鳞系统设备在除鳞作业间歇时对除鳞阀后管路进行预充水,能有效防止管路失水变成空管而集气,消除除鳞作业时引起管路冲击、振动,防止管路设备的损坏,其预填充水方式有低压充水和高压充水两种。非节能型除鳞泵和蓄能器混合供水的除鳞系统,以及除鳞泵直接供水的除鳞系统宜选择高压充水方式,系统增加的能量很少,安全可靠;节能型除鳞泵和蓄能器混合供水的除鳞系统宜选择低压充水方式,系统能耗低,但系统安全性相对较差。     

主换热器热端温差过大的故障分析及处理

针对在空分设备运行过程中主换热器热端温差过大的现象,从换热介质和热端温差变化阶段的系统运行情况入手,分析了热端温差过大的原因,用压缩空气从下塔对换热器至分子筛吸附器出口之间管道进行反吹,排除了故障,空分系统投入正常运行。     

八钢C高炉热风炉冬季保温技术研究与实践

八钢C高炉热风炉在冬季前施工完毕,很多外部条件不具备正常烘炉,为保证热风炉刚砌筑完的耐材质量,提出了一种新的防冻保温方案和采取一系列临时措施,热风炉内部采用了低温烘炉,烟气从冷风管道经倒流休风管排放,同时热风炉外部采用纤维毯保温措施,保证了热风炉炉壳整个冬季的温度控制在零度以上,为以后冬季施工的热风炉工程提出了新的保温方法。     

Influence of pipe processing on the mechanical properties of K60 steel sheet

The mechanical properties of thick steel sheet (13?C27 mm) produced at PAO MK Azovstal?? and the basic metal in K60 pipe (diameter 1220 mm) for the VSTO pipeline manufactured at PAO Khartsyzskii Trubnyi Zavod are subjected to statistical analysis, so as to establish the variation in the mechanical properties of the steel as a function of the sheet thickness and the wall thickness of the pipe and also under the influence of pipe processing.