水煤浆螺旋折流板预热器的流体力学和传热性能的数值模拟  

Numerical simulation of flow and heat transfer of coal water slurry preheaters with helical baffles

作　　者：王斯民[1] 叶树沛 肖娟[1] 王家瑞[1] 文键[2] WANG Si-min;YE Shu-pei;XIAO Juan;WANG Jia-rui;WEN Jian(School of Chemical Engineering and Technology,Xi’an Jiaotong University,Xi’an 710049,China;School of Energy and Power Engineering,Xi’an Jiaotong University,Xi’an 710049,China)

机构地区：[1]西安交通大学化学工程与技术学院,陕西西安710049 [2]西安交通大学能源与动力学院,陕西西安710049

出　　处：《高校化学工程学报》2019年第1期71-80,共10页Journal of Chemical Engineering of Chinese Universities

基　　金：国家自然科学基金(51676146);中央高校基本科研业务费专项资金(xjj2018202)

摘　　要：有研究表明对入炉前的水煤浆进行预热可以提高其气化效率,今利用数值模拟方法,采用非牛顿流体Bingham模型,计算并比较螺旋折流板换热器和弓形折流板换热器预热水煤浆时的流动换热性能。研究螺旋折流板换热器用于水煤浆预热的可行性以及螺旋角、搭接度对其流动换热性能的影响。结果表明:以单位压降的温升作为流动换热综合性能评价指标,螺旋折流板换热器更适于预热水煤浆。对螺旋折流板换热器,螺旋角和搭接度的变化对壳侧温升影响不大,而螺旋角的增大或搭接度减小能使壳侧压降明显降低。大螺旋角和小搭接度的换热器用于水煤浆预热时的流动换热性能更好。在螺旋角18°～40°、搭接度0%～50%,40°螺旋角,0%搭接度的螺旋折流板换热器的流动换热性能最好。研究结果可为选择水煤浆预热器的型式和结构参数提供参考。Preheating of coal water slurry(CWS)before entering into gasifier can improve its gasification efficiency.Bingham model was used to calculate and compare flow and heat transfer performance of shell-and-tube heat exchangers with helical baffles(STHXsHB)and shell-and-tube heat exchangers with segmental baffles(STHXsSB)for CWS preheating.The feasibility of using STHXsHB to preheat CWS and effects of helical angle and overlapped degree on flow and heat transfer were studied.The results show that STHXsHB is more suitable for preheating CWS when the temperature difference per unit pressure drop is used as an evaluation criterion.Temperature difference has little variation with helical angle and overlapped degree,but pressure drop decreases significantly with the increase of helical angle or the decrease of overlapped degree for STHXsHB.STHXsHB shows better flow and heat transfer performance with larger helical angles and smaller overlapped degrees.The shell-and-tube heat exchanger with 40°helical angle and 0%overlapped degree is the best.The results can help to select type and structural parameters of CWS preheaters.

关 键 词：水煤浆预热 Bingham模型 管壳式换热器 螺旋折流板 弓形折流板 数值模拟 非牛顿流体 

分 类 号：TK124[动力工程及工程热物理—工程热物理]