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通过理论分析及现场测试 ,分析了过量空气系数对注汽锅炉热效率的影响 ,得出了在注汽锅炉实际运行中应加强对过量空气系数的监控 ,使过量空气系数降低 ,从而提高注汽锅炉热效率的结论 相似文献
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锅炉是关系到国计民生的重要设备之一,锅炉的过热器是提高锅炉工作效率的辅助设备。然而过热器的换热管爆管事故时有发生。沈阳市某化工厂使用的75/5.3-Y1锅炉的过热器的换热管2000年发生了爆管的事故,在事故的处理处理中,通过对爆管位置及非爆管位置的比较以及现场取样,并对爆裂和非爆裂的换热管进行了化学成分分析,力学性能试验以及金相组织扫描。通过对其结果的比较和分析,结合锅炉的日常工作状态得出该锅炉过热器爆管的原因。 相似文献
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锅炉4管(即水冷壁管、过热气管、再热器管、节煤气管)的硫化物腐蚀,高温氧化,粒子冲蚀问题,长期严重地困扰着我国各电厂的正常运行及发展。 美国焊接学会标准AWSC2.3-541,英国国家标准BS2569Part2均规定了镍铬合金是锅炉管道有效的防高温腐蚀和耐磨涂层。 相似文献
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船舶供油单元燃油原来是由燃油/废气组合锅炉提供蒸汽加热,船舶正常负荷航行时,加热介质由废气锅炉产生蒸汽能满足加热燃油之需,停航与锚泊时由燃油锅炉产生蒸汽来满足燃油加热之需。供油单元加装辅助电加热装置后,船舶停航与锚泊时,在一定时间内(5~6天)由电加热装置替代燃油锅炉;在船舶航行期间,降速航行而导致废气锅炉蒸汽不足时由电加热替代锅炉燃烧产生加热介质保证燃油的温度,保证船舶正常航行,从而节约船舶能耗。 相似文献
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采用宏观检验、壁厚测定及金相分析等方法,对某公司烟化法余热锅炉运行过程中水冷壁管泄漏原因进行分析。结果表明:水冷壁管受热面积灰和结焦严重,产生严重的燃灰腐蚀,加上除盐水循环不良使管内壁形成高温氧化皮,长期高温运行导致材质老化,促成了水冷壁管受热面泄漏的发生。依据烟化法工艺特点提出了预防措施,为烟化法余热锅炉维护保养提供方法。 相似文献
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"超限超载"的产生与发展,蕴藏着深层的内在运作机理,包含着复杂的经济社会原因.其中道路货物运输价格体系的长期扭曲失衡与成本结构的有欠合理是一个不容忽视的根本原因.为此,公路所开展了货运市场运价与成本"治超"专项研究,先后历时一个多月,行程数千公里,深入7省市运输一线,对21家典型企业和个体业户的23辆货车、24条线路进行了跟踪调查,获取了大量的第一手资料与原始数据,并对此进行了解析. 相似文献
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Ngila Mwase† 《运输评论》2013,33(3):191-206
Zambia has attempted to reduce her excessive transport dependency on her traditional transport routes via South Africa and the former Portugese colonies. The costly construction of the Tanzania‐Zambia Railway (TAZARA) was part of this diversification strategy. This article examines the nature, extent and direction of Zambian traffic, including its historical evolution. It explores further the place of TAZARA among the various routes to Mozambican, Angolan and South African ports, and the ensuing actual and potential competition. Future traffic patterns will be influenced not only by the direct and service‐oriented costs of the different lines, but also by the region's volatile and uncertain political climate. 相似文献
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针对海中箱梁现浇施工中的工程量大、工期紧迫、悬臂法施工不能满足工期要求和施工难度大等问题,文章结合青岛海湾大桥箱梁现浇施工实践,介绍以钢管桩支撑作为承载基础,采用贝雷梁与碗扣式支架相结合的支架,成功地解决现浇箱梁施工难题的方法。 相似文献
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Robert E. Paaswell 《Transportation》1973,2(4):351-371
An examination of current population statistics shows that in the U.S. more than half of the population is without immediate access to a car, and in the U.K. more than three-fifths of the population is without access to a car. This phenomenon has been accentuated by national investment in both countries in major highway programs. The term carless refers to more than just households that own no cars. It extends, in households with cars to those without licenses (old and young), the handicapped, and even the licensed drivers who have no access to the family car when it is in use elsewhere (e.g. at work). The most severely effected are those in urban areas and especially the urban poor. Transportation expenses are limited for the poor when other family expenditures (food, shelter) take a high priority. Once the work trip has been satisfied, money for other trips, for the poor, is not always available. One solution to cost-free travel is pedestrianism (walking), but this too is difficult in urban areas where the pedestrian has been overlooked in favor of the car. Solutions to problems of the carless include dial-a-ride, better public transit, and better design of urban form. 相似文献
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