共查询到18条相似文献,搜索用时 156 毫秒
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燃煤电站锅炉水冷壁的高温腐蚀现象较为普遍,特别是锅炉低氮燃烧后,水冷壁的高温腐蚀情况加剧,影响锅炉的安全运行.以670 MW超临界燃煤电站煤粉垂直浓淡分离燃烧锅炉水冷壁高温腐蚀为例,从煤粉分配、还原性气氛、二次风分配等方面分析了水冷壁高温腐蚀的原因,并制定了相应的防范措施. 相似文献
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基于某热电厂实际情况,分析该厂煤粉锅炉水冷壁高温腐蚀的机理、高温腐蚀的影响因素并探讨抑制措施。 相似文献
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由于生活垃圾成分复杂,生活垃圾焚烧发电锅炉的水冷壁的高温腐蚀问题也更为复杂,腐蚀会导致管壁过薄,对锅炉运行产生严重的安全隐患。文中通过对某台垃圾焚烧发电锅炉的腐蚀情况进行研究,并分析该台垃圾焚烧发电锅炉水冷壁腐蚀产物的元素含量,结合垃圾成分,运行中焚烧炉出口O_2/CO的含量,推断该锅炉水冷壁的腐蚀主要为高温Cl腐蚀。并针对水冷壁的腐蚀,采用涂覆Cr-Ni防腐材料对该锅炉第一烟道水冷壁进行了表面防腐,经半年的运行观察,该防腐涂层的防腐效果较好。 相似文献
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燃煤锅炉水冷壁烟侧高温腐蚀的机理及影响因素 总被引:9,自引:0,他引:9
随着对环保要求的日益提高以及煤粉锅炉向大容量高参数发展,电厂燃煤锅炉水冷壁高温腐蚀现象的发生日趋频繁,有的甚至已经影响到锅炉运行的安全性与经济性。作者系统地论述了水冷壁高温腐蚀的类型以及形成机理,分析了影响高温腐蚀的各种因素,为解决煤粉煤炉水冷壁高温腐蚀提供了一定的理论依据。 相似文献
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前后墙对冲旋流燃烧锅炉由于炉内燃烧组织方式和炉膛结构特点,水冷壁高温腐蚀主要发生在主燃区和还原区的左右两侧墙上,通过锅炉的摸底工况试验,诊断锅炉运行存在的问题,在此基础上进行燃烧优化调整,降低了水冷壁近壁区域烟气中还原性气体和腐蚀性气体的含量,以此来减缓水冷壁高温腐蚀的速率. 相似文献
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大型锅炉水冷壁高温腐蚀探讨 总被引:8,自引:0,他引:8
从理论和实际出发 ,阐述了水冷壁发生高温腐蚀的类型 ,大型贫煤锅炉水冷壁发生高温腐蚀的原因 ,四角切圆燃烧方式防止高温腐蚀的措施。针对石洞口电厂锅炉改造 ,提出防止高温腐蚀的具体措施。 相似文献
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Stress corrosion cracking (SCC) is an important degradation mechanism to be considered for safety assessment of nuclear piping components made of austenitic steels, especially in the heat-affected zones. Damage due to SCC occurs in a susceptible material, in a corrosive environment, in the presence of high temperature and high applied/residual stresses. The operating conditions and the environmental conditions show variations during the lifetime of the power plant. Also, there will be variations in micro-structural properties of the material of piping components. These variations should be taken into account while assessing the safety of the piping component against SCC. This can be accomplished by treating the relevant variables as random or fuzzy depending upon the source and type of uncertainty. In this paper, an attempt has been made to compute the fuzzy failure probabilities of a piping component against SCC with time, using an approach combining the vertex method with the Monte Carlo simulation technique. The initiation and propagation stages of stress corrosion cracks are modelled using a modified PRAISE approach. The degree of sensitisation, material fracture toughness, yield strength, ultimate strength and applied stress are considered as random variables, while operating temperature and oxygen concentration are considered as fuzzy variables. The R6 procedure is used in the computation of the fuzzy failure probabilities. The usefulness of the approach is demonstrated through an example problem. 相似文献
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针对某电厂600 MW墙式对冲燃烧锅炉在低氮燃烧改造后存在严重的水冷壁高温腐蚀问题,采取LYCTWA型贴壁风系统对其进行了高温腐蚀治理改造。通过全炉膛数值模拟与现场试验相结合的方法,研究了侧墙壁面区域的烟气成分分布以及不同的贴壁风布置方案对炉内燃烧及高温硫腐蚀的影响。结果表明:模拟结果与电厂实际腐蚀区域相吻合,腐蚀区域主要集中在第2层主燃烧器至燃尽风间的侧墙区域。加装了贴壁风系统后,数值模拟和试验结果均显示侧墙还原性气体体积分数大幅降低,水冷壁贴壁气氛得到显著改善。 相似文献
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中央空调系统的安全运行是确保世博中心稳定运营的关键,提高系统可靠性、稳定性和安全性是保障运营的关键.基于模糊综合评价方法对世博中心中央空调系统进行风险评价.根据中央空调系统体系,将中央空调系统的模糊综合指标体系分为冷热源系统、输配系统和末端设备,运用层次分析法计算了各指标间的权重,最后运用模糊综合评价方法计算了中央空调系统的风险水平分值,从而实现对中央空调系统的风险因素的定性分析和定量计算,为其运营保障提供科学依据. 相似文献
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The laminar unsteady natural convection in a cubic cavity is comprehensively studied here using a high accuracy temporal-spatial pseudospectral method. In this study, the cavity is filled with air and one of its sidewalls is submitted to sinusoidally varying temperature, while constant lower temperature is imposed on the opposing sidewall and other sidewalls are adiabatic. Computations are performed to explore the effects of several influential factors on the fluid flow patterns and heat transfer performances within the cavity, including Rayleigh number and the amplitude and period of pulsating sidewall temperature. Numerical results reveal that the heat transfer enhancement is complexly determined by the above influential factors, and the heat transfer resonance is observed in the case of a large Rayleigh number and amplitude of pulsating sidewall temperature. The three-dimensional effects on fluid flow patterns and heat transfer are discussed. Finally, the backward heat transfer is quantitatively studied. 相似文献