乌拉盖褐煤半焦燃烧特性试验研究

Experimental study on combustion characteristics of Wulagai lignite semi-coke

为了解褐煤半焦的燃烧特性,以乌拉盖褐煤低温热解半焦为研究对象,在西安热工研究院有限公司自燃试验台上,采用电厂用煤煤质指标的评价体系及测试方法对其进行了试验研究。结果表明:乌拉盖褐煤半焦属于低水分、低挥发分以及高热值煤种,其燃烧性能优异,极易着火燃尽,着火稳定性较好,与国内典型烟煤性质接近,燃用时无需过多采用稳燃措施;但由于其灰熔融性较低,并具有严重的结渣倾向,为防止尾部对流受热面出现严重的结渣与积灰,建议炉膛出口烟温不高于1 000℃,且在运行中需加强吹灰,对于新建机组锅炉,应采用低氧燃烧技术以及较为严格的分级配风措施,以实现低NOx排放。

Aiming at obtaining the combustion characteristics of lignite semi-coke, this paper takes the Wul- agai lignite semi-coke pyrolyzed at low temperature as the research object to carry out experiments on self- ignition test bench built in Xi＇an Thermal Power Research Institute. The evaluation system and test meth- ods for coal property indexes were applied. The experimental results show that, the Wulagai lignite semi- coke was a kind of coal with low moisture,low volatility and high calorific value,and it was easy to be igni- ted and burned out, its combustion stability was excellent and this was close to domestic typical bituminous coal. The Wulagai lignite needs no more consideration of using stable-combustion measures. The ash fusion point of Wulagai lignite semi-coke was low and the slagging tendency was serious, so slagging prevention was a question of primary concern in the design of boiler. In order to prevent serious slagging and dust stratification on the convection heating surface at the tail of the boiler, the furnace outlet gas temperature should be lower than 1 000 ℃, and the blowing should be strengthen during the boiler operation. The 1 000 MW new boiler unit should use low oxygen combustion technology and strict staged air distribution to achieve low NOx emissions. This results could provide reference for domestic new boiler equipment se- lection.