洁净煤技术

2021, v.27;No.132(02) 17-30

[打印本页] [关闭]
本期目录(Current Issue) | 过刊浏览(Past Issue) | 高级检索(Advanced Search)

富氧燃烧颗粒物生成和灰沉积特性研究进展
Research progress on the characteristic of particulate matter formation and ash deposition in oxy-fuel combustion

王越明;刘慧敏;仇兴雷;段伦博;
WANG Yueming;LIU Huimin;QIU Xinglei;DUAN Lunbo;Key Laboratory of Energy Thermal Conversion and Control,Ministry of Education,Southeast University;State Key Laboratory of Coal Combustion,Huazhong University of Science and Technology;

摘要(Abstract):

近年来,世界经济不断发展,人口不断增加,能源消耗随之持续增加,其中化石能源的使用使得全球二氧化碳排放总量居高不下。为了缓解全球碳排放上升趋势,中国承诺在2030年二氧化碳排放达峰并在2050年实现净零排放。为了实现这一目标,需要发展化石能源的清洁高效利用,其中富氧燃烧技术是最有前景的燃煤电厂碳减排技术之一,系统综述了富氧燃烧中的颗粒物生成和灰沉积现象,介绍了氧气浓度、压力及燃料特性对颗粒物生成和灰沉积特性的影响机理。富氧燃烧中生成的颗粒物主要可分为亚微米和微米颗粒,其中亚微米颗粒主要由灰分经气化、冷凝和凝聚过程形成,微米颗粒则主要伴随焦炭破碎过程形成。氧气浓度升高导致火焰温度升高,一方面更多的灰分在高温下气化,促进了亚微米颗粒的生成,另一方面高温加剧了碱金属蒸气和硅铝酸盐粗颗粒的交互反应,导致亚微米颗粒中碱金属含量降低。而压力的上升可能会抑制亚微米颗粒的生成。但氧气浓度和压力对微米颗粒的产率和成分影响均不显著。积灰主要通过惯性碰撞、热泳力、冷凝和化学反应形成。富氧燃烧中氧气浓度上升会促进积灰的生成,一方面因为烟气温度升高,颗粒物黏度降低而在碰撞到壁面后更易黏结形成积灰;另一方面因为亚微米颗粒增多,更多细颗粒可以通过热泳力迁移到换热器表面形成积灰。虽然氧气浓度对外层积灰的成分没有明显影响,但紧贴壁面的内层积灰由于含有较多亚微米颗粒,其成分变化与亚微米颗粒趋势相似。压力升高时,积灰中的硫含量增高而氯含量降低,但对积灰生成速率的影响暂不明确。
In recent years,with the continuous development of world economy and the increasing population,energy consumption is continuously increasing. The consumption of fossil energy has caused the increasing CO_2 emission. In order to alleviate the rising trend of global carbon emissions,China has pledged to reach CO_2 emission peak in 2030 and achieve CO_2 emission in 2050. In order to achieve this goal,it is necessary to develop the clean and efficient use of fossil energy. Oxy-fuel combustion is one of the most promising carbon capture technology for coal power plant. In this paper,the particulate matter and ash deposit formation in oxy-fuel combustion were systematically reviewed. The influence mechanism of oxygen concentration,pressure and fuel characteristics on the formation of particulate matter and ash deposition characteristics was introduced. Particulate matters generated from oxy-fuel combustion can be divided into submicron and micron particles. Submicron particles are formed through vaporization,nucleation and coagulation,while micron particles are formed through char fragmentation. Higher oxygen concentration can lead to the increase of flame temperature. On the one hand,more ash is vaporized at high temperature,which promotes the formation of submicron particles; on the other hand,. more alkali contents can be scavenged from submicron particles due to the enhanced interaction between alkali vapors and aluminosilicate particles. It is also found that elevated pressure can inhibit the formation of submicron particles. However,the effect of oxygen concentration and pressure on the yield or composition of micron particles is not obvious. Ash deposits are mainly formed through inertial impaction,thermophoresis,condensation and chemical reaction. More ash deposits are formed under oxy-fuel combustion with higher oxygen concentration,this can be explained from two reasons. Firstly,due to the increase of flue gas temperature,ash particles have lower viscosity and thus are easier to be captured on heat transfer surface. Secondly,more submicron particles can migrate to the surface of heat exchanger to form ash deposits through thermophoresis force. Although compositions of outside deposits are not significantly affected by oxygen concentration,compositions of inside deposits change along with submicron particles because submicron particles contribute the formation of inside deposits. When the pressure increases,the sulfur content in the ash increases and the chlorine content decreases,,but the effect of pressure on ash deposition rate is still unclear.

关键词(KeyWords): 第2代富氧燃烧技术;二氧化碳捕集;污染物控制;颗粒物;灰沉积
the second generation oxy-fuel combustion technology;carbon dioxide capture;pollution control;particulate matter;ash deposition

Abstract:

Keywords:

基金项目(Foundation): 国家重点研发计划资助项目(2018YFB0605301)

作者(Author): 王越明;刘慧敏;仇兴雷;段伦博;
WANG Yueming;LIU Huimin;QIU Xinglei;DUAN Lunbo;Key Laboratory of Energy Thermal Conversion and Control,Ministry of Education,Southeast University;State Key Laboratory of Coal Combustion,Huazhong University of Science and Technology;

Email:

DOI: 10.13226/j.issn.1006-6772.CCUS20093002

参考文献(References):

文章评论(Comment):

序号(No.) 时间(Time) 反馈人(User) 邮箱(Email) 标题(Title) 内容(Content)
反馈人(User) 邮箱地址(Email)
反馈标题(Title)
反馈内容(Content)
扩展功能
本文信息
服务与反馈
本文关键词相关文章
本文作者相关文章
中国知网
分享