分批模拟连续带液操作流化床的传热研究

Heat Transfer of Batch Simulating Continuous Fluidized Bed with Wet Particles

通过分批模拟连续干燥实验，建立了相应的热量和质量传递模型; 对流化床带液操作时气体与粒子之间的传热系数，粒子之间的传热系数进行了研究，得到了带液操作流化床中流化气速、平均粒径和湿粒子含率对传热系数的影响关联式。对理解气相法聚乙烯冷凝模式操作中的传热提供了帮助。

The batch simulating continuous drying experiments were performed, and heat and mass transfer model were built, where gas-particles and particle-particle heat transfer coefficients for fluidized bed with wet particles were determined and analyzed. Moreover, the correlations among fluidizing velocity, mean particles diameter, wet particles fraction and heat transfer coefficients were obtained. Results showed particle-particle heat transfer contributed to the whole heat transfer considerably, about 30～35%, and higher fluidizing velocity, smaller particle diameter and lower wet particles fraction were good for heat transfer in fluidized bed with wet particles. The conclusions obtained are helpful to understand the condensed mode operation of gas-phase fluidized bed polyethylene.