Abstract: The design condition of CFB boiler in SINOPEC Luoyang Company is 100% petroleum coke. When 100% petroleum coke is using in operation, the furnace bed temperature, the limestone consumption, the carbon content of fly ash are all higher than the design value, and the boiler efficiency is slightly lower than the design value. Long term 100% using petroleum coke will lead to boiler coking, especially cyclone separator coking and coke feeder blockage and coke breaking, which will affect the safe and stable operation of boiler. The checking condition is 50% petroleum coke+50% anthracite. In actual operation, the coal blending ratio is adjusted according to the factors such as inventory and price of coal and coke. With the increase of coal blending ratio, under the rated load, the rotating velocity of coke feeder and slag cooler increases. When 80% coal is blended, the ash is not transported in time, resulting in the high material level of the ash hopper and the low SO₂ content at the furnace outlet. At the same time, with the increase of coal blending ratio, the amount of gangue in the fuel entering the furnace increases, the ash increases, and the wear of water wall increases. Considering the long-term operation of water wall, the coal blending ratio is generally 50%~60%.

Key words: CFB boiler, petroleum coke, anthracite, coal blending ratio, water wall wear

摘要： 中国石油化工股份有限公司洛阳分公司CFB锅炉设计工况为100%石油焦。100%烧石油焦运行时,炉膛床温、石灰石耗量、飞灰含碳量均高于设计值,锅炉效率略低于设计值。长期全烧石油焦会导致锅炉结焦尤其是旋风分离器结焦和给焦机堵焦、断焦,影响锅炉安全平稳运行。因此采用50%石油焦+50%无烟煤的校核工况,实际运行时根据煤焦库存及煤焦价格等因素调整掺煤比例。运行结果显示:随着掺煤比例的提高,在额定负荷情况下,给焦机转速和冷渣器转速增加,80%掺煤时输灰不及时造成灰斗高料位,炉膛出口SO₂值低;同时随着掺煤比例的增加,入炉燃料中矸石量增加且灰分增加,水冷壁磨损呈加剧趋势。考虑水冷壁长周期运行因素,运行时一般选取掺煤比例50%～60%。

关键词: CFB锅炉, 石油焦, 无烟煤, 掺煤比例, 水冷壁磨损