运行参数对超临界甲烷流动换热特性的影响  

Analysis of Influence of Operation Parameters on Heat Transfer Characteristics of Supercritical Methane

作　　者：伍经纬 郑文科 李选平 姜益强 WU Jingwei;ZHENG Wenke;LI Xuanping;JIANG Yiqiang

机构地区：[1]哈尔滨工业大学建筑学院,黑龙江哈尔滨150001 [2]寒地城乡人居环境科学与技术工业和信息化部重点实验室,黑龙江哈尔滨150090 [3]广东美芝制冷设备有限公司,广东佛山528300

出　　处：《煤气与热力》2023年第11期I0013-I0018,I0046,共7页Gas & Heat

摘　　要：采用数值模拟方法研究了运行参数(入口温度、运行压力、质量流率)对超临界甲烷在螺旋管内流动换热特性的影响。通过螺旋管内表面传热系数及比摩擦压力降表征管内流动换热性能,对管道出口截面速度与温度的分布进行分析。结果表明:质量流率、运行压力恒定时:表面传热系数随入口温度升高呈现先增加后降低的变化趋势,且在拟临界温度附近达到峰值;比摩擦压力降随入口温度升高逐渐增加。质量流率、入口温度恒定时:比摩擦压力降随运行压力减小而增加。运行压力、入口温度恒定时:表面传热系数随质量流率增大而增加,且质量流率越大,表面传热系数随入口温度变化越明显;比摩擦压力降随质量流率增大而增加,且质量流率越大,比摩擦压力降随入口温度变化趋势越明显。入口温度、质量流率恒定时:随着运行压力增大,出口截面的平均流速逐渐减小,但二次涡结构以及速度分布形式变化不大;运行压力越大,出口截面的高温区域越贴近壁面。入口温度、运行压力恒定时:随着质量流率增加,出口截面的高速区域逐渐趋于管道中心分布且所占面积逐渐变小,管道内二次流强度有所增强且二次涡结构有所改变;出口截面的温差降低,且温度渐变方向与水平方向夹角逐渐减小。The numerical simulation method was used to study the effects of operating parameters(inlet temperature,operating pressure and mass flow rate)on the heat transfer characteristics of supercritical methane flow in spiral tubes.The heat transfer coefficient and specific friction pressure drop on the inner surface of the spiral pipe were used to characterize the heat transfer performance of the flow inside the tube,and the distribution of velocity and temperature at the outlet section of the tube was analyzed.The results show that when the operating pressure and mass flow rate are constant,the surface heat transfer coefficient shows a trend of increasing first and then decreasing with the increase of the inlet temperature,and the surface heat transfer coefficient reaches its peak value near the quasi-critical temperature.In addition,the specific friction pressure drop gradually increases with the increase of the inlet temperature.When the inlet temperature and mass flow rate are constant,the specific friction pressure drop increases with the decrease of the operating pressure.When the inlet temperature and operating pressure are constant,the surface heat transfer coefficient increases with the increase of the mass flow rate,and the greater the mass flow rate,the more obvious the surface heat transfer coefficient changes with the inlet temperature.The specific friction pressure drop increases with the increase of the mass flow rate,and the greater the mass flow rate,the more obvious the trend of the specific friction pressure drop changes with the inlet temperature.When the inlet temperature and mass flow rate are constant,the average flow velocity of the outlet section gradually decreases with the increase of the operating pressure,but the secondary vortex structure and velocity distribution form change little.The greater the operating pressure,the closer the hightemperature area of the outlet section is to the wall surface.When the inlet temperature and operating pressure are constant,with the increase of the mass f

关 键 词：超临界甲烷 螺旋管 流动换热特性 表面传热系数 比摩擦压力降 

分 类 号：TK124[动力工程及工程热物理—工程热物理]