防腐镀(涂)层管束表面对流凝结换热特性  

Convection condensation heat transfer characteristics on different antiseptic pipe surfaces

作　　者：王帅[1] 吴新[1] 李诗[1] 籍晓洋 赵长遂[1] 

机构地区：[1]东南大学能源热转换及其过程测控教育部重点实验室,南京210096

出　　处：《东南大学学报（自然科学版）》2016年第2期289-296,共8页Journal of Southeast University：Natural Science Edition

基　　金："十二五"国家科技支撑计划资助项目(2012BAA02B01-02)

摘　　要：为了考察低温烟气余热回收过程中防腐镀（涂）层管束表面的耐蚀性能和维持珠状凝结的能力,分别对紫铜管和Ni-P镀层、Ni-P-Cu镀层和聚四氟乙烯（PTFE）涂层管表面的腐蚀过程和含湿气体（水蒸气和空气混合,水蒸气质量分数为6%~16%）横掠这4种单排水平管束的对流凝结换热过程进行了实验研究及分析.结果表明：Ni-P镀层和Ni-P-Cu镀层管表面耐蚀性能明显优于紫铜管,PTFE涂层管表面具有最佳的耐蚀性能;Ni-P镀层、Ni-P-Cu镀层和PTFE涂层管束凝结换热系数比铜管管束分别提高5%-35%,14%~61%和10%~48%,具有明显促进珠状凝结的能力,Ni-P-Cu镀层管束具有最佳的凝结换热效果.在低温烟气余热回收的实际应用中,当烟气的腐蚀性较大时,优先选择PTFE涂层换热管束;当烟气的腐蚀性较小时,则首选换热效果最好的Ni-P-Cu镀层换热管束.对实验数据进行多元线性回归分析,得到了含湿气体横掠这4种单排水平管束的对流凝结复合换热实验关联式,关联式预测值与实验值的相对误差在±15%以内,因而关联式具有较高的准确性.To investigate the corrosion resistance and condensation characteristics on different antiseptic pipe surfaces during flue gas heat recovery,the corrosion tests on the surfaces of copper pipes,Ni-P,Ni-P-Cu and polytetrafluoroethylene（ PTFE） coating pipes and the convection condensation heat transfer experiments on the four pipes during flue gas heat recovery were conducted. In the heat transfer experiments,water vapor mass fraction of wet flue gas was ranged from 6% to 16%. The mixture of air and water vapor was adopted to simulate the actual flue gas and the cooling water flowed in pipes. It is found that the corrosion resistance of Ni-P and Ni-P-Cu coating pipes is superior to that of copper pipes,and PTFE coating pipes have the optimal corrosion resistance. Besides,compared with copper pipes,the condensation heat transfer coefficients of Ni-P,Ni-P-Cu and PTFE coating pipes increase by 5% to 35%,14% to 61%,and 10% to 48%,respectively. Ni-P-Cu coating pipe surfaces achieved optimal condensation heat transfer. In the practical application of flue gas heat recovery,while the corrosivity of flue gas is serious,PTFE coating pipes should be given preference. However,when it is slight,Ni-P-Cu coating pipes are the first choice. Based on multiple linear regression analysis of the experimental data,empirical correlations of convection condensation heat transfer of the four pipes during flue gas heat recovery are obtained. The relative errors between the values from the empirical correlations and the experimental measurements are within ± 15%,which proves that the empirical correlations possess high accuracy.

关 键 词：凝结 对流 传热 腐蚀 余热回收 

分 类 号：TK11[动力工程及工程热物理—热能工程]