燃烧器区水冷壁(水冷套)分类比较及设计分析

对垂直管圈和螺旋管圈水冷套进行了结构形式、结构特点和设计事项归纳总结.并重点介绍了垂直管圈四角切圆水冷套与螺旋管圈单隔墙水冷套设计注意事项.通过对垂直管圈和螺旋管圈水冷套的结构形式和结构特点的对比,从设计和制造角度进行了分析,不同锅炉形式,不同燃烧器布置需要的水冷套结构也不同.     

直流锅炉与螺旋管圈水冷壁

直流锅炉具有许多特点，在工业发达的国家采用直流锅炉比较多，特别是超临界机组，必须采用直流锅炉。在我国采用直流锅炉的比重不大，对直流锅炉的优缺点了解不多，因此有必要对直流锅炉作进一步的介绍，为发展超临界机组打下基础．直流锅炉水冷壁结构比较复杂，目前主要采用的有螺旋管圈和垂直管圈二大型式，本文重点介绍螺旋管圈，这种管圈十分适用于超临界变压运行机组．图８．     

超临界压力塔式直流锅炉螺旋管圈水冷壁吸热偏差的试验研究

以1000MW超临界压力塔式直流锅炉为例,对不同负荷下螺旋管圈水冷壁的吸热偏差进行了测量和计算．结果表明：螺旋管圈水冷壁的吸热偏差随着机组负荷的改变而变化,负荷越高,吸热偏差越小,在满负荷下,热偏差系数趋于1．在同一负荷下,由下部螺旋管圈和上部垂直管屏构成的水冷壁管吸热偏差比垂直管屏水冷壁的吸热偏差小;螺旋管圈水冷壁对改善炉内热负荷分布不均效果显著．     

四种类型锅炉的制造和安装特点浅析

本文对亚临界参数下的控制循环锅炉,自然循环锅炉,半塔式布置螺旋管圈直流锅炉和垂直管圈的UP型直流锅炉的主要部件的制造和安装进行了简要介绍和比较。并提出上海锅炉厂目前已具有开发和制造半塔式螺旋管圈直流锅炉的能力。     

垂直管圈和螺旋管圈直流锅炉

直流锅炉的水冷壁有的是采用带再循环的垂直管圈,也有的是采用螺旋管圈。这两种型式锅炉的运行都是成功的(表1)。本文将对这两种型式的锅炉在其可能应用的范围内进行比较。全负荷再循环垂直管圈锅炉和螺旋管圈锅炉之间,在制造费用和运行费用上的差别是很小的。在设计正确和尺寸适当的情况下,     

单相螺旋管圈动态特性研究

从过程基本方程出发,建立了单相螺旋管圈及垂直管圈的动态特性方程,并经过二次建模,得到了能够直接求解的微分方程组,将理论计算结果与试验曲线做了比较,证明了模型的正确性,所得结果对进一步研究直流锅炉螺旋管圈水冷壁动态特性具有一定的参考意义。     

超临界锅炉螺旋管圈区域刚性梁结构分析

超临界螺旋管圈区域刚性梁因水冷壁形式的不同而区别于垂直管圈刚性梁,结构形式,荷载传递方式等均采用特殊形式,以合理的结构保证锅炉平稳、安全运行。     

超临界直流锅炉螺旋管圈水冷壁流量分配及壁温计算

根据回路和节点所遵守的质量守恒、动量守恒和能量守恒方程,建立了计算螺旋管圈水冷壁流量和壁温的数学模型.在此基础上,对1台350 MW超临界燃煤锅炉在不同负荷下的水冷壁流量分配及壁温分布进行了计算.结果表明:在锅炉最大连续蒸发量(BMCR)、75%BMCR及30%BMCR负荷下,螺旋管圈水冷壁的流量偏差不超过±6%,工质出口温差不超过10 K,流量偏差和热偏差均较小;各负荷下管壁温度均处于管子的许用温度范围之内,锅炉运行安全可靠.     

超临界锅炉螺旋管圈水冷壁热负荷在线监测的研究

对超临界锅炉螺旋管圈水冷壁烟气热负荷在线监测进行研究,针对超临界螺旋管圈水冷壁的特点,考虑在线监测的要求,在特征管的水冷壁背火侧安装温度测点,根据温度测量数据计算出烟气侧平均热负荷。由现场运行数据的计算结果符合烟气热负荷分布规律。可作为水冷壁壁温计算及偏差调整的基础数据。为水冷壁在线监测提供了一种新方法。     

塔式螺旋管圈锅炉是我国当前应发展的新炉型

当前电网运行要求提供大功率调峰机组,而塔式螺旋管圈直流锅炉是一种适合的炉型.它具有优良的水动力特性、热偏差小、煤种适应性好、防蚀性能优越、金属耗量少及占地面积小等优点.故本文提出应发展塔式螺旋管圈直流锅炉作为我国的一种新炉型.     

等离子束淬火区的组织转变特点

等离子束淬火时，淬硬层与基体之间基本没有过渡区，整个淬硬区的组织近乎全部为隐针马氏体，故硬度高，且硬度在整个硬化层没有明显的变化；淬硬层略有浮凸，并受到来自未流传火的基体的挤压力，这对于提高硬化带的接触疲劳强度是有利的。     

Energy consumption and economic growth in the light of meeting the targets of energy policy in the EU: The bootstrap panel Granger causality approach

The aim of the paper is to assess linkages between energy consumption and economic growth in the light of compliance with the EU energy policy targets stated in the climate and energy package for 2020 in the European Union member states in the period 1993–2011. The study is divided into two main stages. During the first one, using cluster analysis methods, four groups of countries which met three energy policy targets stated in the package at similar levels were identified. During the second stage, the bootstrap Granger panel causality approach proposed by Kònya (2006) was used to verify the hypothesis of causality between energy consumption and economic growth in the countries from four groups created in the previous step. The global financial crisis was also taken into account. The results obtained reveal that the level of compliance with energy policy targets influences linkages between energy consumption and economic growth. The results indicate causal relations in the group of countries with the greatest reduction of greenhouse gas emissions, the highest reduction of energy intensity and the highest share of renewable energy consumption in total energy consumption. In the remaining groups the results mostly confirm the neutrality hypothesis.     

Experimental Observation of Two Phase Flow of R123 Inside a Herringbone Microfin Tube

Vapor-liquid two phase flow behavior of R123 inside herringbone microfin tubes has been studied. Herringbone microfin tube is a kind of internally finned tube in which microfins are installed inside the tube where the microfins form multi-V-shape in flow direction. For the present experiment three different types of herringbone microfin tubes with helix angle B = 8, 14 and 28 are used. Experimental observations showed how flow diverges and converges inside herringbone microfin tube due to fin arrangement. The effect is more remarkable for larger helix angle. From the measurements of the cross-sectional liquid flow rate distribution, the liquid removal and collection and the entrained droplet are discussed. Quantity of liquid droplets is increased with increase of helix angle. The tube with helix angle B = 28 shows higher quantity of liquid droplets than others.     

竖直螺旋槽管壁面液膜在蒸发/冷凝时的传热特性的研究

研究竖直螺旋槽管壁面液膜在传热条件下的液膜形成及流动特性，建立了单组分流体的物理和数学模型并得出解析解，且分析了壁面液膜在蒸发，冷凝及无热传输时的液膜厚度分布及速度分布，结果表明，液膜的形状主要受表面张力影响，在表面内弯处流膜较厚，而在槽道起始部液膜较薄，相对于光滑直管，竖直螺旋槽管壁面液膜具有均匀的厚度分布和更好的传热传质性质，特别在冷凝时壁面液膜更薄且分布更加均匀。     

基于正交设计的大型海上风电齿轮箱多级螺旋角优选研究

以某5 MW海上风电机组两级行星一级平行齿轮箱为研究对象,建立以其第一、二、三级齿轮螺旋角（A、B、C）为三自变量因素,以5°、8°、11°、15°为四离散水平的16组正交试验方案,基于Simpack软件完成对应方案的虚拟样机建模及动力学仿真,对各因素各水平下的均载特性、振动特性进行评估,对正交试验结果的有效性进行验证。研究结果表明：行星级的均载特性主要与该级螺旋角有关,同时受螺旋角影响,一般情况下,螺旋角越大,均载特性越好;影响高速输出轴后轴承位置振动的主要因素为第三级齿轮螺旋角,且当C在8°附近时,振动信号较小。研究结果可为大型海上风电机组齿轮螺旋角精细化设计提供理论支撑。     

强化管内沸腾换热实验研究

主要研究在低过热度下微槽对流动沸腾换热特性的影响，分别以单工质甲醇和甲醇与甲苯的混合物为工质对不同流量情况下光管、直槽管和螺旋槽管的流动沸腾换热特性进行了实验研究。研究结果表明：对单工质甲醇来说，螺旋槽管可以明显起到强化传热作用，而且流量越低，强化传热效果越明显。对混合工质来说，当流量较低时，螺旋槽管强化传热效果不明显，而在流量较高时，强化传热效果比较明显。无论是单工质还是混合工质，直槽管在实验所能达到的壁面温度条件下不能起到明显的强化传热效果。还给出了螺旋槽管强化传热的定性解释。     

水平螺旋槽管壁面液膜特性的研究

研究水平螺旋槽管壁面液膜的形成机理及流动特性。通过建立单组分流体的物理和数学模型，得出了液膜的速度、厚度解析解，并分析了水平螺旋槽管的几何条件对壁面液膜形成的影响。结果表明：液膜的形状主要受表面张力和槽道表面几何形状的影响，在槽道谷底处较厚，而在槽道起始处较薄。相对于光滑直管，水平螺旋槽管壁面液膜具有更均匀的厚度分布，故具有更好的传热传质性能。     

防止衬环加工断裂的工艺探讨

为解决活塞环衬环滚压成型过程中的断带问题,通过试验,分析出了断带原因。经过选用合适的不锈钢带,改变模具设计,生产出合格产品。文章还对衬环材料影响产品的性能方面进行了阐述。     

Experimental Performance Comparison of Shell-Side Heat Transfer for Shell-and-Tube Heat Exchangers with Different Helical Baffles

In this study, experiments were carried out to study the effects of baffle overlap proportion on the shell-side flow resistance and heat transfer performance of the shell-and-tube heat exchangers with helical baffles (STHXsHB). Three STHXsHB with an overlap proportion of 10% and helix angles of 20°, 30°, and 40° were tested. Comparisons were made of the experimental data of the STHXsHB with the same helix angles but 50% overlap proportion. The theory of entransy dissipation was employed to evaluate the irreversible loss in STHXsHB with different helix angles and overlap proportions. The results indicated that both the baffle overlap proportion and the helix angle have a great effect on the shell-side flow resistance and heat transfer. For a given helix angle, the comprehensive performance of STHXsHB with small overlap proportion is always better than that with large overlap proportion at the same mass flow rate or Reynolds number on the shell side. However, for the same heat transfer area, working conditions, and helix angle, the STHXsHB with large baffle overlap proportion has less irreversibility in the heat exchange process, according to the theory of entransy dissipation. In addition, experimental results demonstrated that the configuration of the relatively large helix angle and baffle overlap proportion is the preferred alternative in STHXsHB.     

Tube bundle replacement for segmental and helical shell and tube heat exchangers: Experimental test and economic analysis

In this investigation, the second test analysis with more comprehensive evaluation with a focus on fouling mitigation, increased running-time and economic analysis are shown and then, the thermal design procedure for tube bundle replacement of critical heat exchanger of Butene-1 unit in Petrochemical Company as a case study are described. Finally, experimental data for the average heat transfer coefficient and pressure drop of shell-side in segmental and helix bundles are measured and calculated for the mass flow rate of 14.24 kg/s and then these data are compared with the data from code and EXPRESS. Moreover, additional comparison between code and EXPRESS results are provided to ensure the accuracy of calculation program in various mass flow rates. Based on the same shell in the case studies, the results showed that in addition to improved heat transfer performance of the helix bundle over segmental bundle, helix bundle achieved two to three times longer operational run times. From economic point of view, the results for replacement of segmental bundle with a helix bundle showed that initial and installation costs of helix bundle to segmental bundle could be increased, but maintenance and operating costs can be decreased in the helix bundle, 60% and 20%, respectively. Comparison between code and EXPRESS results with experimental data for the mass flow rate of 14.24 kg/s showed that the deviation in heat transfer coefficient and pressure drop are quite reliable for segmental and helix bundles.