摘要
采用数值模拟方法,对螺旋管结构参数(螺旋管内直径、螺旋直径及螺旋升角)对超临界甲烷在螺旋管内流动换热特性的影响进行研究。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,对螺旋管出口横截面的流速与温度分布进行分析。结果表明:螺旋直径及螺旋升角相同时,随着螺旋管内直径减小,表面传热系数达到峰值时的入口温度及峰值、比摩擦压力降均增大。螺旋直径及螺旋升角相同时,随着螺旋管内直径增大,出口横截面的平均流速逐渐增大,管道内的高温流体所占横截面面积越大且越贴近壁面,且横截面最高温度增大。螺旋管内直径及螺旋升角相同时,随着螺旋直径增大,管内表面传热系数峰值小幅度降低,不同入口温度范围表面传热系数与螺旋直径呈现不同变化规律。此外,比摩擦压力降随着螺旋直径增大而逐渐降低。螺旋管内直径及螺旋升角相同时,随着螺旋直径减小,出口横截面流速增大且横截面流速的分层现象越明显。随着螺旋直径增大,管内高温流体所占横截面面积逐渐减少且逐渐远离壁面,同时横截面温差降低。螺旋升角对超临界甲烷在螺旋管内的流动换热性能影响较小。
The numerical simulation method was used to study the influence of spiral tube structural parameters(spiral tube inner diameter,spiral diameter and spiral lead angle)on the flow heat transfer characteristics of supercritical methane in the spiral tube.The flow heat transfer performance in the spiral tube was characterized by the heat transfer coefficient of the inner surface of the spiral tube and the specific friction pressure drop,and the flow velocity and temperature distribution of the exit cross section of the spiral tube were analyzed.The results show that when the spiral diameter and lead angle are the same,as the inner diameter of the spiral tube decreases,the inlet temperature when the surface heat transfer coefficient reaches the peak value,the peak value,and the specific friction pressure drop all increase.When the spiral diameter and lead angle are the same,as the inner diameter of the spiral tube increases,the average flow velocity at the outlet cross-section gradually increases.The larger the cross-sectional area occupied by the high-temperature fluid in the tube,the closer it is to the wall,and the highest temperature in the cross-section increases.When the inner diameter and lead angle of the spiral tube are the same,as the spiral diameter increases,the peak value of the surface heat transfer coefficient inside the tube decreases slightly.The surface heat transfer coefficient and the spiral diameter show different changes in different inlet temperature ranges.In addition,the specific friction pressure drop gradually decreases with the increase of the spiral diameter.When the inner diameter and lead angle of the spiral tube are the same,as the spiral diameter decreases,the outlet cross-sectional flow velocity increases and the stratification phenomenon of cross-sectional flow velocity becomes more obvious.As the spiral diameter increases,the cross-sectional area occupied by the high-temperature fluid inside the tube gradually decreases and moves away from the wall,while the cross-sectional temperature difference decreases.The lead angle has little effect on the flow heat transfer performance of supercritical methane in the spiral tube.
作者
李选平
郑文科
田中允
姜益强
孙澄
LI Xuanping;ZHENG Wenke;TIAN Zhongyun;JIANG Yiqiang;SUN Cheng
出处
《煤气与热力》
2023年第9期V0010-V0019,共10页
Gas & Heat
关键词
超临界甲烷
数值模拟
螺旋管
流动换热特性
表面传热系数
supercritical methane
numerical simulation
spiral tube
flow heat transfer characteristics
surface heat transfer coefficient
作者简介
第一作者:李选平,男,工程师,硕士,主要从事流体仿真方面工作;通信作者:郑文科,男,讲师,博士,主要从事暖通空调、制冷系统及相关设备研究,多能互补系统与节能减排技术研究等。
