水蒸气对脱灰煤焦O2/H2O燃烧特性的影响

邓立华; 白孟龙; 孙绍增; 赵义军; 冯冬冬

摘要: 为实现“30·60”碳中和的目标，先进的燃烧技术如 Oxy-steam 燃烧能有效减少燃煤 CO2 排放。基于新一代 Oxy-steam 燃烧技术提出的煤基固体燃料-氧-水蒸气燃烧近零排放发电系统(OCCSS)是能实现燃煤 CO2近零排放的发电方式之一。使用脱灰煤作为燃料能省去除尘装置，同时降低煤中灰分对设备的损害。研究脱灰煤在 O2 / H2 O 条件下的燃烧特性，能为后续的燃烧室设计提供理论依据。采用三步酸洗法(HCL-HF-HCL)制取准东脱灰煤，使用高温管式炉在 900 °C 制备常压焦炭，在微型流化床 O2 / H2 O 燃烧实验系统进行温度为 950 °C 、O2 体积分数分别为 5%， 15%，21%，30%、H2 O 体积分数为 10%，25%，40%，60%的快速升温 O2 / H2 O 燃烧实验。研究不同 O2 体积分数条件下，H2 O( g) 对脱灰煤焦的 O2 / H2 O 燃烧特性的影响，探究其对燃烧进程的促进 / 抑制规律。在单颗粒快速升温O2 /H2O燃烧条件下(950 °C)，O2体积分数为5%~30 %时，H2O(g)对脱灰煤的燃烧过程均表现出抑制作用。 O2 体积分数小于 21%时，H2 O(g)体积分数变化对焦炭燃烧的抑制作用尤为明显。 H2O(g)体积分数从 0 增至 60%时，低 O2体积分数(5%，15%)条件下焦炭的转化时间分别为 34.67，23.22 s，是体积分数为 21%时转化时间的 1.81 和 1.21 倍。在不同 H2 O(g)体积分数区间，O2体积分数对焦炭转化的促进效果会改变。 O2体积分数小于 15%时，其体积分数的增加能明显促进焦炭转化;O2体积分数大于 15%时，其作用效果与 H2 O(g)体积分数有关，当 H2O(g)体积分数不大于 25%，O2体积分数的增加对焦炭转化无明显的提升作用。

Abstract: In order to achieve the goal of “30·60” carbon neutrality,the advanced combustion technologies such as Oxysteam combustion can effectively reduce coal fired CO 2 emissions. For the new generation of OxySteam combustion technology,OxyCoal Combustion Steam System for power generation with nearzero emissions (OCCSS) can achieve nearzero emissions of coalfired CO 2. Using demineralized coal as a fuel can save dust removal equipment,and reduce the damage of the ash in the coal to the equipment. Research on the characteristics about the demineralized coal which is used for its combustion under O 2/H 2O conditions can provide a theoretical basis for subsequent combustion chamber design. A three step pickling method（HCL-HF-HCL）is used to prepare Zhundong demineralized coal. A high temperature tube furnace is used to prepare char at 900 ℃. The rapid heating O 2/H 2O combustion experiment at 950 ℃,5%，15%，21%，30% O 2 and 15%,25%,40%,60% H 2O(g) was performed by a micro fluidized bed O 2/H 2O combustion experiment system. Study the effect of H 2O(g) on the O 2/H 2O combustion characteristics of demineralized coal char under different O 2 concentration,and explore its promotion/inhibition law on the combustion process. Under the condition of O 2/H 2O combustion with rapid temperature rise of single particle (950 ℃),when the O 2 concentration range is 5%-30%,H 2O(g) has an inhibitory effect on the combustion process of demineralized coal. When the O 2 concentration is less than 21%,the H 2O(g) concentration change has a particularly obvious inhibitory effect on char combustion. When the H 2O(g) concentration changes from 0 to 60%,the conversion time of char under low O 2 concentration conditions (O 2 concentration:5%,15%) is 34.67 s and 23.22 s,which are 1.81 and 1.21 times of the 21% O 2 conversion time. In different H 2O(g) concentration intervals,the promotion effect of O 2 concentration on char conversion will be changed. When the O 2 concentration is less than 15%,the increase in its concentration can significantly promote the conversion of char. When the concentration of O 2 is greater than 15%,its effect is related to the concentration of H 2O(g). When the concentration of H 2O(g) is below 25%,the increase in O 2 concentration does not significantly improve the conversion of char.

水蒸气对脱灰煤焦O2/H2O燃烧特性的影响

Effect of steam on O2/H2O combustion characteristics of demineralized coal char

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