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本文对空气与高温烧结水泥颗粒的气固换热规律进行了非稳态实验研究和数值模拟。通过实验分析了空气速度、颗粒初始温度、颗粒大小对对流换热系数的影响,水泥颗粒直径为8.88 cm和5.94 cm,水泥颗粒初始温度约为500℃和700℃,空气速度范围1～4 m/s,得到了实验范围内空气绕流烧结水泥颗粒的对流换热经验关联式。结果表明:高温烧结水泥颗粒冷却过程中辐射换热热流密度与对流换热热流密度相当,不可忽略;实验所得准则数Nu_f与Re_d的指数关系为0.5。对直径为8.88 cm的水泥颗粒对应的试验工况进行了数值模拟,数值模拟结果与实验结果符合较好,误差在20%以内。
In this paper, the gas-solid heat transfer laws of air and high temperature cements were studied experimentally and numerically. The effects of air velocity, initial particle temperature and particle size on the convective heat transfer coefficient were analyzed experimentally. The average particle diameter of cement particles was 8.88 cm and 5.94 cm. The initial temperature of cement particles was about 500 ℃ and 700 ℃. The air velocity range was 1 ~ 4 m / s, the empirical correlation of the convective heat transfer of air-entrained sintered cement particles within the experimental range was obtained. The results show that the heat flux density of convective heat transfer during the cooling process of high temperature sintering cement particles is equivalent to that of convective heat transfer, and the exponential relationship between Nu_f and Re_d is 0.5. The experimental conditions corresponding to the cement particles with the diameter of 8.88 cm were numerically simulated. The numerical results agree well with the experimental results, and the errors are within 20%.