论文总字数：44236字

摘 要

东南大学新型串行流化床反应器由1个空气反应器（AR）、2级燃料反应器（FR1和FR2）以及3个隔离器（LS1、LS2和LS3）组成。本文通过在该实验台上开展气固流动特性实验，研究AR、FR和LS流化风量对系统压力分布、物料循环速率以及反应器间的气体混合规律的影响，并对实验数据进行整理分析，获得该串行流化床内的气固流动特性。

实验台设置有6个测压孔，压力通过压力变送器进行采集，经A/D转换器转换成数字信号后由计算机接收。通过对各反应器通入不同种类的气体检测出口气体成分，来研究该串行流化床反应器冷态模型反应器之间的气体混合规律，改变反应器和各隔离器入口流化风量讨论流化风量对反应器间气体串混量以及串混比例的影响。

结果表明，该串行流化床内的床料颗粒主要存在于FR中，AR和FR的流化风量对AR和FR的床层压降以及颗粒循环系数的影响较大；在3个隔离器中，LS2和LS3的流化风量对于系统压降以及颗粒循环影响较小，LS1的流化风量影响显著，LS1的流化风量是颗粒循环速率大小的决定性因素。实验结果表明，该串行流化床内反应器间的气体串混与床层压降以及颗粒循环速率有着密切的联系，LS1中的流化气体大部分进入到FR中，其余少部分进入到AR，AR和LS1流化风量的增大会使LS1中气体分配到AR中的比例增加，而FR流化风量的增大会使这一比例减小。LS2中气体几乎全部进入到FR中，原因可能是LS2上升管上部气体压力较大，阻碍了LS2中气体向上流动。LS1和LS2的存在使得只有极少量气体从AR进入到FR当中，而没有气体从FR串混到AR，这表明LS1和LS2能够起到很好的气体隔离作用，保证AR和FR之间不发生气体串混。

关键词：化学链燃烧；串行流化床；气固流动；气体串混

Experimental Study on Gas-solid Flow Characteristic in

Interconnected Fluidized Beds

Abstract

The new interconnected fluidized beds of SEU is composed of an air reactor (AR), a two-stage fuel reactor (FR1 and FR2) and 3 loop-seals (LS1, LS2 and LS3). This work studies the influences of volumetric flow rate at the inlet of AR, FR and LS on pressure distribution, solid circulation rate and gas leakage of the system, based on gas-solid flow characteristics experiments on this cold-flow model. It presents the gas solid flow characteristics after data analysis.

Six pressure taps are used to measure pressure drop which is converted to digital signal via pressure transmitter collected by computer. Different kinds of gases are injected into AR, FR or LS, and composition of the exhaust gases is detected to study gas leakage of interconnected fluidized beds. The influences of volumetric flow rate at the inlet of AR, FR and LS on gas leakage and gas distribution proportion between reactors is studied by means of changing flow rate at the inlet of AR, FR and LS, respectively.

It is found that the material in interconnected fluidized beds mainly exist in fuel reactor. Besides, the volumetric flow rates at the inlet of AR and FR have a greater influence on pressure distribution and solid circulation rate of the system. Among three loop-seals, the volumetric flow rates at the inlet of LS2 and LS3 have less influence on pressure distribution and solid circulation rate of the system, while the volumetric flow rate at the inlet of LS1 is a decisive factor to particle circulation rate. From the experimental results, it can be seen that there is a close relationship between gas leakage and pressure drop or the particle circulation rate in interconnected fluidized beds. A majority of gases of LS1 flow into FR while the rest of them flow into AR. The improvement of flow rate at the inlet of AR and LS1 will increase the proportion of gas distribution of LS1 to AR while the improvement of flow rate at the inlet of FR does the opposite. Almost the whole gases of LS2 flow into FR, the reason of which may be that the higher pressure of riser over LS2 hinders gases of LS2 flowing upward. There are very few gases flowing into FR from AR and no gases flow into AR from FR because of the setting of LS1 and LS2. It shows that LS1 and LS2 can play a good barrier function to prevent gas leakage, ensuring that there is no gas leakage between AR and FR.

KEY WORDS: Chemical-looping combustion; Interconnected fluidized beds; Gas-solid flow; Gas leakage

目 录

摘 要 I

Abstract II

第一章 绪 论 1

1.1 研究背景 1

1.1.1 温室效应与全球气候变暖 1

1.1.2 CO₂排放与CO₂减排技术 3

1.2 化学链燃烧技术 6

1.2.1 化学链燃烧技术简介 6

1.2.2 载氧体的研究现状 8

1.2.3 化学链燃烧反应器研究现状 10

1.3 本文的研究目的及主要内容 14

第二章 新型串行流化床化学链燃烧反应器冷态模型 15

2.1 实验装置 15

2.2 实验条件及原始参数 16

2.3 实验内容及要求 16

第三章 流化风量对系统压力分布、物料循环速率的影响研究 17

3.1 床层压降分布 17

3.2 空气反应器流化风量的影响 18

3.3 燃料反应器流化风量的影响 19

3.4 隔离器1流化风量的影响 20

3.5 隔离器2流化风量的影响 21

3.6 隔离器3流化风量的影响 22

3.7 结果及讨论 23

第四章 串行流化床反应器间气体混合规律研究 24

4.1 气体串混路径 24

4.2 串行流化床内气体串混特性及反应器流化风量对气体串混的影响 24

4.2.1 隔离器1和隔离器2内气体分配情况 24

4.2.2 气体由空气反应器至燃料反应器串混情况 29

4.2.3 气体由燃料反应器至空气反应器串混情况 30

4.3 结果及讨论 30

第五章 总结与展望 32

致 谢 34

参考文献(Reference)： 35

绪 论

1.1 研究背景

1.1.1 温室效应与全球气候变暖

温室效应的存在最早由Joseph Fourier于1824年发现，后于1859年被实验证实。如图1.1所示，由于大气层中的温室气体对电磁波具有选择吸收性，使得照射在大气层上的短波太阳辐射能够透过大气层射入到地表，而由地表发射出来的长波辐射则被大气层中的温室气体所吸收，大气温度因此上升，从而产生温室效应。

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