不同燃烧压力下煤粉富氧燃烧特性试验研究

Experimental Study on Characteristics of Oxygen-enriched Combustion of Pulverized Coal under Different Combustion Pressures

为了研究不同燃烧压力下煤粉的富氧燃烧特性及烟气成分,运用加压固定床燃烧反应试验系统对不同燃烧压力下的煤粉进行了富氧燃烧试验,结果表明:随着燃烧压力的增大,燃烧中心的温度也随之增大,当燃烧压力大于3.0 MPa时燃烧中心的最高温度不再明显增大,维持在750℃左右;随着燃烧压力的增大,煤粉的着火时间不断缩短,煤粉的燃尽时间先减小后增加,当燃烧压力大于3.0 MPa时,煤粉的着火时间与燃尽时间随着压力的增大不再发生明显的变化;随着煤粉的燃烧,O_2浓度先下降后上升,最后达到进气浓度,当燃烧压力大于3.0 MPa时,O_2浓度在前3 min内的降速较快,说明在此工况下的煤粉燃烧剧烈;CO_2浓度先下降后上升再下降达到进气浓度;CO浓度先上升后下降,随着燃烧压力的增加,燃烧过程中产生的CO浓度降低。

In order to study the characteristics of oxygen-enriched combustion of pulverized coal and smoke compositions under different combustion pressure,the oxygen-enriched combustion test of pulverized coal under different combustion pressure was carried out by using pressurized fixed bed combustion reaction test system. The results showed that the temperature of combustion center increased with the increase of combustion pressure,when the combustion pressure was more than 3.0 MPa,the maximum temperature of the combustion center no longer increased significantly,it maintained at about 750 ℃; with the increase of pressure,the ignition time of pulverized coal was shortened,the burning time decreased at first and then increased,when the combustion pressure was more than 3. 0 MPa,the ignition time and burning time of pulverized coal were no longer change significantly with the increase of combustion pressure; with the burning of pulverized coal,the concentration of O2 decreased at first and then increased,and finally reached the intake air concentration,when the combustion pressure was more than 3.0 MPa,the concentration of O2 decreased rapidly in the first 3 min,indicating that the pulverized coal burned vigorously under such circumstances; the concentration of CO2 decreased at first,then increased and then decreased to reach the intake concentration; the concentration of CO increased at first and then decreased,and with the increase of combustion pressure,the concentration of CO produced during combustion decreased.