脱硫烟囱用GFRP与钛板耐硫酸腐蚀性能研究

发布时间：2018-01-29 11:55

  本文关键词： GFRP 钛板 烟囱 湿法脱硫 腐蚀　出处：《武汉理工大学》2015年硕士论文　论文类型：学位论文

【摘要】：以牺牲环境为代价换取经济发展已被越来越多人认为难以持续,我国以煤为主的能源结构决定了我国属于典型的煤烟型大气污染,对燃煤电厂加装烟气净化设备能够有效降低多种主要大气污染物的排放。我国燃煤电厂主要以石灰石-石膏脱硫工艺为主,其技术特点决定了脱硫烟囱的腐蚀极为严重。玻璃纤维增强树脂基复合材料(GFRP,Glass Fiber Reinforced Plastics)和钛钢复合板是近年应用较为广泛的脱硫烟囱内筒材料,对其耐腐蚀性能进行研究具有很大的现实意义。结合工程实际和文献记载,本文在分析了解湿法脱硫对烟囱造成腐蚀的基本原理和特点以后,认为烟气冷凝液中的主要成分——硫酸是其具备强腐蚀性的重要因素,继而将硫酸溶液的浓度和温度作为影响两种材料耐腐蚀性能的研究方向,通过外观形貌变化、质量变化和力学性能变化评价两种材料在不同浓度(质量分数1%、5%、10%、15%)不同温度(50℃、60℃、70℃、80℃)下的耐腐蚀性能。为探究两种材料在真实环境下的腐蚀行为,本文同时配置了模拟烟气冷凝液作为腐蚀介质以评价其在实际工况下的使用性能。接头是烟囱中的力学薄弱点,其异于筒体的结构特点和制作方式决定了其耐腐蚀性能具有差异性,因此,本文将接头的耐腐蚀性能作为研究重点之一。试验结果表明,在低浓度(1%)硫酸中,GFRP和钛板试样的性能皆能保持稳定,随着硫酸浓度增加,两者的性能都发生了衰减,其中,钛板试样的性能衰减更为明显;温度升高对两种试样耐腐蚀性能的影响都较为显著,在10%硫酸中,70℃下、60天以后和80℃下、45天以后,钛板甚至发生了完全腐蚀溶解;在50℃模拟烟气冷凝液中,GFRP和钛板试样的性能衰减较为微弱,试验周期内质量变化较小,强度保留率超过97%;手糊GFRP接头的耐腐蚀性能与缠绕成型基材具有很大的一致性,而钛板焊接接头的耐腐蚀性能明显弱于钛板基材,在50℃、10%硫酸溶液中,60天以后即失效,且焊接高温对焊缝附近基材的影响巨大。综合试验结果,本文认为玻璃钢与钛板皆能满足脱硫烟囱正常工况下的使用要求,为获得最佳的使用效果,应结合烟囱特点进行差别化选择;但考虑到局部冷凝液浓度升高的影响及接头的可靠性,GFRP要优于钛板。
[Abstract]:Economic development at the expense of the environment has been regarded as unsustainable by more and more people. The coal-based energy structure determines that China belongs to the typical coal-type air pollution. The installation of flue gas purification equipment in coal-fired power plants can effectively reduce the emission of many major atmospheric pollutants. In China, limestone gypsum desulfurization technology is the main technology in coal-fired power plants. The corrosion of desulfurization chimney is very serious due to its technical characteristics. GFRP / glass fiber reinforced resin matrix composite. Glass Fiber Reinforced plastic) and titanium steel composite plate are widely used in recent years. It is of great practical significance to study its corrosion resistance. Combined with engineering practice and literature records, this paper analyzes the basic principles and characteristics of wet desulfurization on the corrosion of chimney. It is considered that sulfuric acid, the main component of flue gas condensate, is an important factor of its strong corrosion, and then the concentration and temperature of sulfuric acid solution are taken as the research direction to influence the corrosion resistance of the two materials. The changes of appearance, quality and mechanical properties of the two kinds of materials were used to evaluate the two kinds of materials at different concentrations (mass fraction 1: 5) at different temperatures (50 鈩，

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