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类型 基础研究 预答辩日期 2017-09-17
开始(开题)日期 2015-12-23 论文结束日期 2017-07-19
地点 热能所一楼会议室 论文选题来源 973、863项目     论文字数 8.6 (万字)
题目 应用水汽相变促进燃煤烟气中细颗粒物及SO3酸雾脱除的研究
主题词 细颗粒物,SO3酸雾,水汽相变,湿法脱硫系统,脱除
摘要 目前,燃煤电站现有污染物控制设备仍无法有效控制细颗粒物及SO3酸雾的排放,大量细颗粒物及SO3酸雾排入大气中,对环境和人体健康造成严重危害。利用水汽相变促进细颗粒物及SO3酸雾凝结长大并加以脱除是一项极具工业应用前景的技术,结合燃煤电站现有污染物控制设备特点,采用水汽相变技术促进传统污染物控制设备协同脱除细颗粒物及SO3酸雾具有重要意义。 利用湿法烟气脱硫(Wet Flue Gas Desulfurization, WFGD)模拟装置,试验考察了塔内水汽相变对WFGD过程中燃煤细颗粒物脱除的促进效果,以及对次生细颗粒物(脱硫过程中产生的细颗粒物)形成的抑制效果。结果表明,脱硫洗涤过程中水汽相变不仅有利于促进燃煤细颗粒物(特别是0.1-1 μm的细颗粒物)的脱除,还可有效抑制次生细颗粒物(特别是1-10 μm的细颗粒物)的形成。 针对燃用褐煤、水煤浆等产生的高湿燃煤烟气,结合实际燃煤电厂污染物控制装置特点,提出了实现脱硫塔内水汽相变促进细颗粒物及SO3酸雾脱除的方法。结果表明,细颗粒物及SO3酸雾脱除效率随脱硫塔入口烟气湿度、脱硫液气比增加而增加,随塔入口烟气温度与脱硫浆液温度升高而降低;该方法可使WFGD系统对细颗粒物数量脱除效率由5-10%提高至35-45%,对SO3酸雾质量脱除效率由35-40%提高至55-65%。此外,针对高温、高硫(SO3)的高湿烟气,还进一步提出了实现低低温电除尘技术与水汽相变技术耦合促进细颗粒物及SO3酸雾脱除的方法,同时提高电除尘器和WFGD系统对细颗粒物及SO3酸雾的脱除效率。结果表明,细颗粒物及SO3酸雾脱除效率随电除尘前原始烟气中SO3浓度、烟气喷水增湿后温降的升高而增加,但较高的脱硫塔入口烟气温度不利于细颗粒物和SO3酸雾脱除;该方法可使细颗粒物的最终数量排放浓度降低35-45%,使SO3酸雾的最终质量排放浓度降低65-75%。 针对燃用烟煤、无烟煤等产生的低湿燃煤烟气,结合实际燃煤电厂污染物控制装置特点,又提出了实现脱硫塔后水汽相变促进细颗粒物及SO3酸雾脱除的方法。首先提出采用脱硫净烟气中添加湿空气实现水汽相变的措施。结果表明,细颗粒物及SO3酸雾的脱除效率随脱硫净烟气温湿度与混合比的增加而提高,随湿空气温度的升高而降低,而湿空气相对湿度对其影响不大;该方法可将细颗粒物的最终数量排放浓度降低25-45%,SO3酸雾的最终质量排放浓度降低15-35%。鉴于脱硫净烟气中直接添加湿空气存在过饱和度分布不均匀与水汽壁面凝结等问题,随后又提出了脱硫塔后水汽相变耦合撞击流技术促进细颗粒物及SO3酸雾脱除的方法。细颗粒物及SO3酸雾一方面经过水汽相变凝结长大,另一方面通过两股气流撞击碰并长大。结果表明,两股气流撞击速度的提高有利于细颗粒物及SO3酸雾脱除效率的增加,且两股烟气存在一个最佳对喷距离,在最佳对喷距离下,脱除效率最高;该方法可将细颗粒物的最终数量排放浓度降低40-50%,使SO3酸雾的最终质量排放浓度降低30-40%。最后,提出了采用脱硫塔后设置氟塑料换热器降低烟气温度实现水汽相变的方法。细颗粒物及SO3酸雾一方面通过水汽相变凝结长大被下游高效除雾器拦截脱除,另一方面通过热泳与扩散泳运动至换热管表面被冷凝液膜捕集。结果表明,细颗粒物及SO3酸雾随脱硫塔后烟气温降的增加而提高,但随脱硫净烟气温度的变化不明显;该方法可将细颗粒物的最终数量排放浓度降低35-40%,使SO3酸雾的最终质量排放浓度降低35-45%。 基于燃煤电站SO2超低排放改造经常采用的单塔双循环及双塔双循环改造工艺,提出通过吸收区浆液降温与双塔间烟气降温的方式实现水汽相变,促进细颗粒物及SO3酸雾脱除的方法。结果表明,针对单塔双循环改造工艺,吸收区浆液温降幅度与液气比的增加均可促进细颗粒物及SO3酸雾的脱除;该方法可将WFGD系统对细颗粒物数量脱除效率从原来的20-25%提高至40-50%,SO3酸雾质量脱除效率由原来的35-40%增至50-60%。针对双塔双循环改造工艺,双塔间烟气降温与第二级脱硫塔内液气比的提高均有利于细颗粒物及SO3酸雾脱除效率的提高;该方法可将细颗粒物数量脱除效率由原来的40-45%提高至55-65%,将SO3酸雾质量脱除效率由原来的60-65%增至70-80%。
英文题目 Study on Improving the Removal of Fine Particles and SO3 Acid Mist in Coal-Fired Flue Gas by Heterogeneous Condensation
英文主题词 fine particles,SO3 acid mist,heterogeneous vapor condensation,heterogeneous condensation, removal
英文摘要 The emissions of fine particles and SO3 acid mist in coal-fired power plants are still difficult to be effectively controlled and large amount of them discharge into the atmosphere, leading adverse impacts to human health and environment. Heterogeneous vapor condensation is one of the most promising preconditioning techniques for improving the removal of fine particles and SO3 acid mist. Fine particles and SO3 acid mist are activated and enlarged by heterogeneous vapor condensation, and then the grown ones can be removed by the traditional pollution control equipment. According to the features of traditional pollution control equipments in coal-fired power plants, it is of great significance to improve the removal efficiency of traditional pollution control equipment for fine particles and SO3 acid mist by heterogeneous vapor condensation. To investigate the removal of coal-fired fine particles and the formation of generated fine particles during the desulfurization process by heterogeneous vapor condensation, the experiments were carried out in a self-design wet flue gas desulfurization (WFGD) system. The results indicate that the supersaturation atmosphere can be established by increasing the humidity and reducing the temperature of the flue gas before WFGD system. In desulfurization process, the application of the heterogeneous vapor condensation not only leads to an improvement of coal-fired fine particle removal (especially for the fine particles with the size in the range of 0.1-1 μm), but also causes an inhibition of generated fine particle formation (especially for the fine particles with the size in the range of 1-10 μm). For the high-humidity flue gas, which is generated by burning lignite, water-coal-slurry, biomass et al, a novel process was proposed to improve the removal of fine particles and SO3 acid mist by heterogeneous condensation during WFGD processes. The results indicate that the removal efficiency of fine particles and SO3 acid mist can be improved by the increase of the inlet flue gas moisture and liquid-to-gas ratio. However, higher temperatures of inlet flue gas and desulfurization slurry are adverse to the improvement of removal efficiency. With the application of this method, the number removal efficiency of fine particles can be improved from 5-10% to 35-45%, and the mass removal efficiency of SO3 acid mist can be improved from 35-40% to 55-65%. Furthermore, for the high-humidity flue gas with high-temperature and high-sulfur (SO3), the other novel process, which is based on the condensation of SO3 and water vapor, was further proposed to abate the emission of fine particles and SO3 acid mist. In this process, the removal efficiencies of electric precipitator (ESP) and WFGD system for fine particles and SO3 acid mist are improved simultaneously. The results indicate that the higher SO3 concentration in flue gas and the larger temperature reduction before ESP are beneficial for the improvement of the removal of fine particles and SO3 acid mist, while the higher flue gas temperature is unfavourable. With the application of this method, the fine particle emissions in the final exhausted flue gas can be reduced by 35-45%, and the SO3 acid mist emissions can be reduced by 65-75%. For the high-humidity flue gas, which is generated by burning anthracite, bitumite, et al, a novel process based on heterogeneous vapor condensation in desulfurized flue gas was proposed to reduce the emission of fine particles and SO3 acid mist in final exhausted flue gas. First, the supersaturation atmosphere is established by adding humid air into desulfurized flue gas. The results indicate that with the increasing of mixing ratio and desulfrized flue gas humiture, the emission of fine particles and SO3 acid mist decrease. With the increase of humid air temperature, the emission of fine particles and SO3 acid mist increase. Moreover, the humidity of humid air only has a little influence. With the application of this method, the fine particle emissions in the final exhausted flue gas can be reduced by 25-45%, and the SO3 acid mist emissions can be reduced by 15-35%. Since the supersaturation atmosphere established in the desulfurized flue gas by adding humid air is not uniform, the other novel process, which combined of heterogeneous vapor condensation and two impinging streams (TIS), was further proposed to reduce the emissions of fine particles and SO3 acid mist. In this process, fine particles and SO3 acid mist can not only be enlarged by heterogenous vapor condensation in supersaturation atmosphere, but also can be enlarged by collision-coalescence in impinging region. With the application of this method, the fine particle emissions in the final exhausted flue gas can be reduced by 40-50%, and the SO3 acid mist emissions can be reduced by 30-40%. Furthermore, the process for establishment of supersaturation atmosphere by decreasing desulfurized flue gas temperature via heat exchanger was proposed. The results indicate that the influence of original desulfurized flue gas temperature is not obvious, thus the applicability of this process is better. With the application of this method, the fine particle emissions in the final exhausted flue gas can be reduced by 35-40%, and the SO3 acid mist emissions can be reduced by 35-45%. For the single-scrubber with dual circuit (SSDC) desulfurization process and double-scrubber with dual circuit (DSDC) desulfurization process, the novel processes were proposed to establish the supersaturation atmosphere in absorption region of SSDC and second scrubber of DSDC via the application of a heat exchanger. The results indicate that for the single-scrubber with dual circuit, the removal of fine particles and SO3 acid mist can be improved by decreasing the temperature of slurry in absorption region and increasing the liquid-to-gas ratio in absorption region.With the application of this method, the number removal efficiency of fine particles can be improved from 20-25% to 40-50%, and the mass removal efficiency of SO3 acid mist can be improved from 35-40% to 50-60%. For the double-scrubber with dual circuit, the higher temperature drop in heat exchanger and the higher liquid-to-gas ratio in second scrubber are benefical for the removal of fine particles and SO3 acid mist. With the application of this method, the number removal efficiency of fine particles can be improved from 40-45% to 55-65%, and the mass removal efficiency of SO3 acid mist can be improved from 60-65% to 70-80%.
学术讨论
主办单位时间地点报告人报告主题
东南大学 2014.10.09 热能所一楼会议室 吴昊 工作回顾与近期安排
东南大学 2015.04.21 热能所一楼会议室 吴昊 工作回顾与近期安排
清华大学 2015.7.19-22 北京会议中心 吴昊 Removal of fine particles from coal combustion by heterogeneous condensational enlargement in wet flue gas desulfurization
东南大学 2016.08.25 礼西二楼会议室 吴昊 973汇报内容准备
东南大学 2016.11.28 礼西二楼会议室 吴昊 上周工作回顾及本周工作安排
东南大学 2016.05.25 热能所一楼会议室 潘丹萍 石灰石石膏湿法烟气脱硫试验进展
东南大学 2016.12.05 礼西二楼会议室 潘丹萍 工作安排-石灰石石膏法烟气脱硫
东南大学 2016.09.18 礼西二楼会议室 黄荣廷 2016年9月工作报告973相关试验计划
东南大学 2016.10.26 礼西二楼会议室 黄荣廷 2016年10月工作报告
     
学术会议
会议名称时间地点本人报告本人报告题目
32nd Annual International Pittsburgh Coal Conference 2015.10.5-8 Pittsburgh, PA USA Removal of Fine Particles from Flue Gas by Heterogeneous Condensation in WFGD System
2016年973学术研讨会 2016.10.14-16 江苏南京翠屏山宾馆 应用水汽相变增强WFGD系统脱除细颗粒物及SO3酸雾的研究
     
代表作
论文名称
Improving the removal of fine particles by heterogeneous condensation during WFGD processes
Improving the removal of fine particles from desulfurized flue gas by adding humid air
Abatement of fine particle emission by heterogeneous vapor condensation during wet limestone-gypsum
Improving the removal efficiency of sulfuric acid droplets from flue gas using heterogeneous vapor c
Removal of sulfuric acid aerosols in desulfurized flue gas by adding moist air
The abatement of fine particles from desulfurized flue gas by heterogeneous vapor condensation coupl
Abatement of fine particle emission from a coal-fired power plant based on the condensation of SO3 a
Removal of fine particles from flue gas by heterogeneous condensation in WFGD system
 
答辩委员会组成信息
姓名职称导师类别工作单位是否主席备注
黄亚继 正高 教授 博导 东南大学
袁竹林 正高 教授 博导 东南大学
段钰锋 正高 教授 博导 东南大学
杨宏旻 正高 教授 硕导 南京师范大学
薛建明 正高 研究员级高工 硕导 国电科学技术研究院
      
答辩秘书信息
姓名职称工作单位备注
王沛 其他 工程师 东南大学