Knowledge Management System Of Guangzhou Institute of Energy Conversion, CAS
| 煤粉低尘燃烧器实验研究 | |
| 蒋利桥 | |
| Thesis Advisor | 陈恩鉴 |
| 2001 | |
| Degree Grantor | 中国科学院广州能源研究所 |
| Place of Conferral | 中国科学院广州能源研究所 |
| Degree Name | 硕士 |
| Degree Discipline | 热能工程 |
| Keyword | 低尘 旋流 液排渣 旋风燃烧 |
| Abstract | 本文对端面旋流进风新型煤粉低尘燃烧器进行了冷态流场模拟实验和热态实验研究，得出如下结论：采用端面旋流进风结构的燃烧器，燃烧筒内压力场和速度场相似性、对称性很好；各工况下轴向速度分布中环室回流均存在，且环室回流几乎贯穿整个燃烧器，切向速度存在双峰值现象，径向速度与轴向速度具有相同的数量级，不可忽略；出口直径大小对速度场影响很大，出口直径的大小决定中心回流区域的大小；随出口直径的减少，环室回流率增大，但相应阻力增大。进口直径大小主要影响燃烧筒头部流场，进口直径的减小有利于增大头部环室和中心回流率；燃烧筒长度增大时，中心回流区后移，燃烧器头部和尾部环室回流率均增大。一次风为旋流时有利于增大燃烧器头部环室回流率和中心回流率，当流量比 Q_1/Q_2＝5％ 时，环室回流率和中心回流较大。当一次风采用直射流的进风方式时，在燃烧器头部，中心回流区完全消失，对燃烧极为不利。综上所述，理想工况燃烧器结构为：D_(out)=200mm, L=600mm, D_(int)=220mm, 一次风为旋流，Q_1/1_2=5%。采取端面旋流进风结构的煤粉低尘燃烧器热态运行可靠，燃烧灰熔点较低（1400℃ 左右）的煤种，能实现顺利排渣的目的，燃烧器内温度可达 1600－1800℃，燃烧效率达 99.77%, 捕渣率为 90％ 左右。 |
| Other Abstract | In this paper, we have contrived a new type of lower-ash coal pulverized combustor, and obtained several important conclusions by studying the cold-condition model and hot-condition experiment. The velocity field and the pressure field are more symmetrical than the average combustor. The annular back-flow exists in the axial velocity distribution in all experimental conditions, it is so deep that it nearly puts through whole the combustor. The "two peak-value" phenomena exists in the tangential velocity distribution. The magnitude of radial velocity is the same scale as the axial velocity's. The magnitude of D_(out)/D is the key factor to influence the cold velocity field, the less it is, the more annular back-flow ratio increases. Inlet diameter influences the velocity field in the headspace, both annular back-flow and central back-flow rate increase while the magnitude of D_(in)/D is less. Adding the length can lead central back-flow to move back, annular and central back-flow rate to increase respectively. With the same swirl direction, primary air's entrance can enlarge the central back-flow, the best condition is flux ratio Q_1/Q_2=5%, but if the way of primary air's entrance is straight injection, the central back-flow will disappear, it is harmful for pulverized coal to be combusted. In a word, the preferred condition construction is D_(out)=200mm, L=600mm, D_(int)=200mm, Q_1/1_2=5%. In the hot-condition experiment, the combustor can run normally, when the ash fusion is not too high (about 1400℃), the slag can flow out easily, and the temperature can reach 1600-1800℃ in the combustor. The combustion efficiency is 99.97% and slag-capture rate is about 90%. |
| Pages | 64 |
| Language | 中文 |
| Document Type | 学位论文 |
| Identifier | http://ir.giec.ac.cn/handle/344007/3847 |
| Collection | 中国科学院广州能源研究所 |
| Recommended Citation GB/T 7714 | 蒋利桥. 煤粉低尘燃烧器实验研究[D]. 中国科学院广州能源研究所. 中国科学院广州能源研究所,2001. |
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