贫煤与煤气混烧锅炉掺烧试验

Experimental Study on Lean Coal and Gas Combined Combustion Boiler

为了研究掺烧对锅炉排烟温度、过热蒸汽温度、飞灰和灰渣含碳量以及锅炉热效率的影响,并提出相应的运行优化方式,对某钢厂75 t/h混烧锅炉分别进行了焦炉煤气与煤粉混烧、全燃高炉煤气与焦炉煤气以及高、焦炉煤气和煤粉混烧的燃烧试验。结果表明:锅炉混烧焦炉煤气与煤粉时,锅炉热效率能够达到82.7%,但不利于企业煤气平衡;锅炉全燃高炉煤气与焦炉煤气时,锅炉热效率能够达到85.2%,但只能维持较低负荷运行;在燃用实际贫煤条件下,锅炉混烧高、焦炉煤气与煤粉,当三者热值比分别为35%、35%与30%时,排烟温度、飞灰含碳量和灰渣含碳量较改造前分别下降了4.5℃、1.06%和1.09%,热效率为77.21%,优化后较优化前减少燃料消耗与节煤率分别为226.1 kg/h和3.3%。

In order to study the effects of blending ratio on exhaust temperature,superheated steam temperature,carbon content in fly ash and slag,and boiler thermal efficiency,and put forward the corresponding operation optimization method,mixed combustion experiments of COG(coke oven gas)with coal,BFG(blast furnace gas)with COG,and coal,BFG with COG were performed in a 75 t/h combined combustion boiler,respectively.The results show that the boiler thermal efficiency can reach 82.7%under the condition of mixed combustion of COG and coal,but the operating mode is not economical for the gas balance of plant.When burning BFG and COG in the boiler,the boiler thermal efficiency can reach 85.2%but low loading operation.After the mode of 35%BFG heat value,35%COG heat value and 30%lean coal heat value is applied in the boiler,the exhaust temperature,carbon content in fly ash and slag decreases by 4.5℃,1.06%and 1.09%,respectively.The boiler thermal efficiency is 77.21%.Moreover,the fuel consumption reduces by 226.1 kg/h and the coal saving ratio is 3.3%.