烧嘴参数对耐火砖热变形的影响分析

热变形是引起耐火砖脱落的重要因素之一,烧嘴参数对热变形的影响很大。针对烧结套筒式双旋流烧嘴的结构特点,采用热流固耦合方法建立了烧嘴的有限元模型,首先利用FLUENT分析了温度场和流场,结合测量数据验证了模型的正确性;然后对耐火砖通道进行热结构分析,获得了通道的热变形分布;最后采用响应面方法设计了81组试验进行模拟计算,获得了烧嘴结构参数和操作参数对耐火砖通道表面温度和热应变的影响规律。结果表明:燃烧器负荷增加、外侧空气预热温度增加会显著地增加耐火砖的热变形,比如燃烧器负荷增加1%,耐火砖应变增加0.75%;增加外侧空气流速、增加内侧空气预热温度有助于缓解耐火砖的热变形,比如外侧空气流速增加1.0%,耐火砖应变减少0.30%;增加外侧空气旋流片角度既有助于强化混合燃烧,又能降低耐火砖的热变形量。

Influence of burner parameters on thermal deformation of refractory brick

Thermal deformation is one of the important factors that caused the firebrick to fall off, and the parameter of the burner has great influence on the thermal deformation. Based on the structural characteristics of the sintered sleeve type dual-swirl burner, the finite element model of the burner was established by means of the thermo-fluid-solid coupling method. FLUENT was used to compare the temperature field and flow field, and to verify the correctness of the model with measured data. After that, the thermal structural analysis of the refractory brick channel was carried out, and the thermal deformation distribution of the channel was obtained. Then, 81 groups of experiments were designed by the response surface method. The influence of the burner structure parameters and operating parameters were emphatically analyzed on the surface temperature and thermal strain. The results show three rules. Increasing the burner load and the outside air preheating temperature will significantly increase the thermal deformation of refractory bricks. For example, if the burner load increases by 1%, refractory brick strain increases by 0.75%. Increasing air flow rate and the inside air preheating temperature can alleviate the thermal deformation of refractory bricks. For example, if the outside air flow rate increases by 1.0%, refractory brick strain reduces by 0.30%. Increasing the outside air swirl angle can strengthen mixed combustion and reduce the thermal deformation of refractory bricks.