气-固循环流化床螺纹管换热器中的颗粒碰撞行为和传热性能  

Particle collision behavior and heat transfer performance in a gassolid circulating fluidized bed heat exchanger with threaded tube

作　　者：姜峰[1,2] 朱凌云 LEDUO Elizabeth Nawa MOKHAMMAD Faridl Robitoh 李修伦 JIANG Feng;ZHU Lingyun;LEDUO Elizabeth Nawa;MOKHAMMAD Faridl Robitoh;LI Xiulun(School of Chemical Engineering and Technology,Tianjin University,Tianjin 300072,China;Tianjin Key Laboratory of Chemical Process Safety and Equipment Technology,Tianjin 300350,China)

机构地区：[1]天津大学化工学院,天津300072 [2]天津市化工安全与装备技术重点实验室,天津300350

出　　处：《化学工业与工程》2024年第6期158-168,共11页Chemical Industry and Engineering

基　　金：化学工程国家重点实验室开放项目(SKL-CHE-18B03);天津市科技支撑计划重点项目(2009ZCKFGX01900)

摘　　要：将流化床换热防垢节能技术应用于螺纹管换热器,设计并构建了内螺纹循环流化床换热装置。采用空气作为气相工质,聚甲醛(POM)颗粒和3种不同粒径的玻璃珠(GB)作为惰性固体颗粒,考察了空气流量(12~20 m^(3)·h^(-1))、热通量(1~3 kW·m^(-2))和颗粒类型等操作参数对颗粒碰撞行为和传热性能的影响。结果表明,惰性固体颗粒的加入可以强化螺纹管的传热,同时也增加了系统的压降。实验范围内,传热增强因子最大可达27.2%,此时V=16 m^(3)·h^(-1),q=2 kW·m^(-2),加入的颗粒为POM颗粒。压降比率最大不超过38.5%。气相和固相的碰撞加速度信号的特征频率范围分别为0~1000 Hz和5000~25000 Hz。其中在两相流碰撞中,颗粒碰撞起主导作用。随着空气流量的增加,信号功率增大,传热增强因子先增大、后减小。总体来说,传热增强因子随着热通量的增加而减小;热通量同空气流量相比对信号功率的影响较小。GB颗粒的传热增强因子和信号功率小于POM颗粒,且基本上随其颗粒粒径的增加而增大。压降比率主要随空气流量或热通量的增加而增大,随GB颗粒粒径增加而减小。GB3和POM颗粒的沉降速度相近,但粒径较大的POM颗粒的压降比率更大。Fluidized bed heat transfer and anti-fouling technology is applied to threaded tube heat exchanger.A heat exchange device of internal threaded circulating fluidized bed is designed and built to investigate the particle collision behavior and heat transfer performance under different operating parameters,such as air flow rate(12—20 m^(3)·h^(-1)),heat flux(1—3 kW·m^(-2)),and particle type.Air and four types of particles are selected as working media.The results show that the heat transfer of threaded pipes can be enhanced by adding inert solid particles,but the system pressure drop is also increased.The maximum heat transfer enhancing factor can reach 27.2%with the addition of POM particles at V=16 m^(3)·h^(-1)and q=2 kW·m^(-2),and the maximum pressure drop ratio is no more than 38.5%within the experimental range.The characteristic frequency ranges of gas-phase and solid-phase collisions are 0—1000 Hz and 5000—25000 Hz,respectively.Particle collision plays a dominant role in the gas-solid two-phase flow collisions.As air flow rate increases,the signal power increases but the heat transfer enhancing factor first increases and then decreases.As heat flux increases,the heat transfer enhancing factor generally decreases.The effect of heat flux on signal power is relatively smaller compared with air flow rate.The heat transfer enhancing factor and signal power of GB particles are smaller than those of POM particles,and basically increase with the increase in GB particle size.With the increase in air flow rate or heat flux,the pressure drop ratio mainly shows an increasing trend,and decreases with the increase in GB particle size.The pressure drop ratio of POM particles is greater than that of GB3 particles.

关 键 词：颗粒碰撞行为 传热强化 气-固循环流化床换热器 螺纹管 压降 

分 类 号：TQ021.1[化学工程]