| 摘要: |
| 目前国内外对液化天然气(LNG)接收站的开架式气化器中超临界天然气的流动换热实验研究非常少，本文为了研究开架式气化器中竖直管内超临界流体的流动换热特性，搭建了竖直单管超临界流体换热实验平台。以液氮代替液化天然气，研究了氮入口压力、水温和水流量等不同参数对换热的影响。结果表明:在拟临界温度以下，表面传热系数随着压力的增大逐渐减小，但拟临界温度以后，这种趋势相反；当水流量足够大时，氮出口温度取决于管外水温而不是水侧流量。最后，基于实验数据拟合出了适用于竖直圆管内超临界低温流体流动换热的半经验关联式，关联式预测值和实验值的平均绝对偏差为8.42％，可以准确预测竖直加热管中超临界氮的表面传热系数。 |
| 关键词: 气化器 传热系数 超临界氮 竖直管 关联式 |
| DOI： |
| 投稿时间：2020-03-30 修订日期：2020-07-01
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| 基金项目: |
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| Experiment on Heat Transfer Characteristics of Supercritical Nitrogen in Vertical Tube for Open Rack Vaporizer |
| Cheng He,Ju Yonglin,Fu Yunzhun |
| (Institute of Refrigeration and Cryogenics, Shanghai Jiao Tong University;College of Mechanical Engineering ，Shanghai University of Engineering Science) |
| Abstract: |
| Open rack vaporizers are basic load vaporizers that are widely used in LNG terminals. However, there are few experimental studies on the fluid flow and heat transfer behaviors of supercritical natural gas. In this study, nitrogen was used to replace natural gas, and the heat transfer characteristics of supercritical nitrogen in a heated vertical tube were investigated experimentally. The effects of various operating parameters, including nitrogen pressure, inlet temperature, and mass flow of water, on the heat transfer characteristics were investigated. The surface coefficient of heat transfer decreased with increasing pressure below the pseudocritical temperature, while the variation of the surface coefficient of heat transfer was opposite to that of the pseudocritical temperature. The outlet temperature of nitrogen was determined by the water temperature instead of the mass flow rate when the mass flow rate of water was sufficiently large. A new correlation was developed for the heat transfer of a supercritical cryogenic fluid based on the experimental data, and the mean absolute relative deviation between the predicted values and the experimental data was 8.42%. This new correlation can be used to accurately predict the surface coefficient of heat transfer of supercritical nitrogen in a vertical heating tube. |
| Key words: vaporizer cofficient of heat transfer supercritical nitrogen vertical tube correlation |
