多孔陶瓷板红外燃烧器头部能量损失系数计算

Calculation of Energy Loss Coefficient of Porous Ceramic Plate Infrared Burner Head

多孔陶瓷板红外燃烧器特有的头部结构使得针对大气式燃烧器头部能量损失系数K_(1)的计算方法不再适用。推导出适用于多孔陶瓷板红外燃烧器的K_(1)修正计算公式,建立单火孔完全预混燃烧模型,将利用Fluent软件数值模拟得到的火孔内预混气体的沿程温度分布函数与K_(1)修正计算公式结合,经迭代计算得到K_(1)计算值,与实测数据对比,验证了该方法的可靠性。模拟分析了K_(1)受燃烧器热负荷、陶瓷板热导率和孔隙率的影响,结果显示:随着燃烧器热负荷增加,火孔内预混气体的沿程温度和K_(1)计算值均呈下降趋势,且热负荷越小,下降幅度越明显。K_(1)计算值受陶瓷板热导率影响不大,仅随热导率增加呈现小幅上升趋势。陶瓷板孔隙率越大,K_(1)计算值越大;火孔内预混气体沿程温度在靠近入口的区段随着孔隙率增大而下降,在靠近出口的区段随着孔隙率增大而升高。

The unique head structure of porous ceramic plate infrared burner makes the calculation method of head energy loss coefficient K_(1) of atmospheric burner no longer applicable.The K_(1) correction calculation formula suitable for porous ceramic plate infrared burner is derived,and a single fire hole fully premixed combustion model is established.Combining the temperature distribution function of the premixed gas in the fire hole obtained by numerical simulation with Fluent software and the K_(1) correction calculation formula,the K_(1) calculation value is obtained through iterative calculation,and compared with the measured data,the reliability of the method is verified.The effects of burner heat load,ceramic plate thermal conductivity and porosity on K_(1) are simulated and analyzed.The results show that as the heat load of the burner increases,the temperature the premixed gas in the fire hole and the calculation value of K_(1) both show a downward trend,and the smaller the heat load,the more significant the decrease.The calculation value of K_(1) is not greatly affected by the thermal conductivity of the ceramic plate,and only shows a slight upward trend with the increase of thermal conductivity.The greater the porosity of the ceramic plate,the greater the calculation value of K_(1);the temperature of the premixed gas in the fire hole decreases with the increase of porosity in the section near the entrance,and increases with the increase of porosity in the section near the exit.