450t/h CFB锅炉风水冷选择性冷渣器的传热特性

Heat Transfer Characteristics on Air-water Selected Type Slag-cooler in a 450t/h CFB Boiler

为深入研究风水冷选择性冷渣器的传热过程和运行参数的影响规律,以某电厂450 t/h CFB锅炉配备的多仓式流化床风水冷选择性冷渣器为对象,依据各仓室的传热特点,建立了各仓室的热平衡模型。对设计工况下的出口渣温进行了校核计算,分析在不同进渣量和流化风量下,各仓室的运行特性对出口渣温的影响规律。研究表明,额定工况下,推荐的各仓室设计风量不能保证冷渣器的最低安全要求;结合冷态模化实验和传热计算结果,指出必须提高各仓室的流化风量,并给出了满足炉渣流化和冷却要求的流化风量;建议运行中严格控制进渣量并及时调整各仓室的冷却风量。

In order to analyze the heat transfer process and effects of operating parameters, the heat transfer models are established for each chamber of air-water selected type slagcooler in a 450 t/h CFB boiler. The present paper investigates the outlet-slag temperatures of chambers under recommended air flowrates and the effects of operation of each chamber on discharged slag temperature under different slag and air flowrates. The computed results show that the discharged slag temperature cannot be cooled down to 150℃ with recommended air flowrate. Combined with results in cold-modeling experiment, it dedicates the air flowrate for each chamber needs to be improved and the suggested air flowrates are presented for safety operation. It is of importance to control slag flowrate into slag-cooler and to regulate the corresponding airflow with slag flowrate during practical operation.