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超(超)临界压力锅炉垂直管屏水冷壁水动力与热偏差调整建议 总被引:2,自引:2,他引:0
垂直管圈超(超)临界压力锅炉一般都在水冷壁管入口安装节流圈,以调节工质流量,使其与对应区域的热负荷相匹配,但是该类型锅炉在投运后往往出现水冷壁节流圈结垢、水动力和热偏差,以致发生爆管.通过对水冷壁结构特点的分析,对爆管原因进行了研究,参考亚临界垂直管圈直流锅炉水动力调整经验,提出超(超)临界压力锅炉垂直管屏水冷壁系统改进和进行水动力调整的建议,即减少水冷壁管入口节流圈数量,在水冷壁管(屏)的入口安装调节装置以及加装水冷壁管屏的监视测点等. 相似文献
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双面水冷壁和垂直多回程管圈的停滞问题前一节的分析指出,自然循环锅炉的水冷壁管组和一些直立度比较大的直流锅炉垂直上升管圈中,在低负荷时吸热偏小的管子中可能发生停滞的问题。停滞问题在各种书 相似文献
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超超临界直流锅炉的水冷壁有螺旋管圈和一次上升垂直管圈两种型式.后者具有结构简单、支吊方便和阻力小的优点.但南于我国第一代300MW直流锅炉的垂直管圈在调峰运行时频繁爆管,所以人们担心这种管圈存热负荷有变化时能否安全运行.泰州电厂1 000 MW超超临界锅炉采用从日本三菱公司引进的技术,水冷壁是带中间混合集箱进口设节流罔的一次上升内螺纹管管圈.为了消化引进技术,通过计算分析,发现这种管圈在BMCR时的静态水动力特性属于强制循环特性.但当偏差管的吸热量增加15%时,出口温度只升高7.7℃.不会影响安全运行. 相似文献
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针对1 000 MW超超临界机组锅炉内螺纹管垂直管屏水冷壁变压运行特性进行了理论分析.重点分析了低质量流速下的水冷壁热偏差对流量偏差的影响关系和内螺纹管传热特性以及直流锅炉水冷壁强制流动特性被自然循环特性部分低偿的流动特性. 相似文献
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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. 相似文献
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Jiancong Dong Tuo Zhou Xiaojiang Wu Jian Zhang Haojie Fan Zhongxiao Zhang 《热科学学报(英文版)》2018,27(6):592-601
This paper presented a coupled heat transfer model combining the combustion in the furnace and the ultra-supercritical(USC) heat transfer in the water wall tubes. The thermal analysis of the spiral water wall in a 1000 MW double reheat USC boiler was conducted by the coupled heat transfer simulations. The simulation results show that there are two peak heat flux regions on each wall of spiral water wall, where the primary combustion zone and burnt-out zone locate respectively. In the full load condition, the maximal heat flux of the primary combustion zone is close to 500 kW/m~2, which is higher than that in the conventional single reheat USC boilers. The heat flux along the furnace width presents a parabolic shape that the values in the furnace center are much higher than that in the corner regions. The distribution of water wall temperature has a perfect accordance with the heat flux distribution of the parabolic shape curves, which can illustrate the distribution of water wall temperature is mainly determined by heat flux on the water wall. The maximal water wall temperature occurs at the middle width of furnace wall and approaches 530°C, which can be allowed by the metal material of water wall tube 12Cr1MoVG. In the primary combustion zone, the wall temperatures in half load are almost close to the values in 75% load condition, caused by the heat transfer deterioration of the subcritical pressure fluid under the high heat flux condition. The simulation results in this study are beneficial to the better design and operational optimization for the double reheat USC boilers. 相似文献
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1000MW塔式直流锅炉炉膛水冷壁管壁温度和热负荷分布的试验研究 总被引:1,自引:1,他引:0
对2台1 000MW超超临界压力塔式直流锅炉炉膛水冷壁管壁温度和热负荷分布进行了测量和计算,并对不同负荷工况、不同磨煤机投运方式下的热负荷和管壁温度分布规律以及炉膛上部垂直水冷壁的热负荷分布进行了分析.结果表明:1 000MW塔式直流锅炉炉膛热负荷的分布规律与其他四角切圆燃烧锅炉炉膛热负荷的分布规律基本一致.由于在最上层的燃烧器上方布置了燃尽风,对炉内烟气的扰动加强,导致沿管长方向的热负荷在54m标高处波动较大;在燃尽风喷嘴中心线以上,因受到燃尽风进入炉膛的影响,水冷壁热负荷大幅度下降.为了避免炉膛大比热区传热恶化,可以将处于拟临界点附近的水冷壁布置在低热负荷区域. 相似文献
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For heat treating cylindrical metal billets, their lay-out in a furnace usually resembles that of an in-line heat-exchanger tube bank, with the air flows orthogonal to the billets. For maximum effectiveness of transferring thermal energy from the forced convecting air to the billets, the optimal horizontal pitch-to-diameter ratio for the billets should be 1·33 ± 0·05. For this same purpose it is advantageous to employ a vertical spacing (between the billets) as large as can be permitted for a given load of billets. 相似文献
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