摘要
使用甲烷代替液化天然气(LNG),对超临界LNG在单根蛇形管内的流动与传热特性进行了数值模拟,分析了流体物性、进口速度、压力及壁温对超临界流体传热特性的影响。结果表明,表面传热系数的总体变化趋势与定压比热容随温度压力的变化类似,表面传热系数沿管程先增大后减小;而在远大于拟临界温度的区域,除弯管处由于二次流出现突变外,表面传热系数渐趋稳定。壁温、入口速度及压力都会对表面传热系数的峰值位置和大小产生影响。增大压力可以改善超临界区域传热恶化现象;进口速度对传热影响较大,随着进口速度增大,表面传热系数显著增加。
Using methane instead of liquefied natural gas(LNG), the flow and heat transfer characteristics of supercritical LNG in a single coil tube were numerically simulated. The effects of fluid properties, inlet velocity,pressure and wall temperature on heat transfer characteristics of supercritical fluids were analyzed. The results showed that the overall change trend of surface heat transfer coefficient was similar to that of constant pressure specific heat capacity with temperature and pressure. Surface heat transfer coefficient increased first and then decreases along the tube path. In the region far larger than the quasi-critical temperature, the surface heat transfer coefficient tended to be stable except for the sudden change of secondary flow at the elbow. Wall temperature, inlet velocity and pressure all affect the peak position and numerical value of the surface heat transfer coefficient. Increasing pressure could improve the deterioration of heat transfer in supercritical region. The inlet velocity had a great influence on heat transfer. With the increase of inlet velocity, the surface heat transfer coefficient increased significantly.
作者
吴晓林
靳书武
武锦涛
银建中
WU Xiaolin;JIN Shuwu;WU Jintao;YIN Jianzhong
出处
《化工装备技术》
CAS
2019年第1期23-27,共5页
Chemical Equipment Technology
关键词
超临界甲烷
对流换热
数值模拟
蛇形换热管
Supercritical methane
Convective heat transfer
Numerical simulation
Coil tube
