化工学报 ›› 2019, Vol. 70 ›› Issue (4): 1282-1290.DOI: 10.11949/j.issn.0438-1157.20180695

• 流体力学与传递现象 • 上一篇    下一篇

垂直上升管内超临界CO2 流动传热特性研究

朱兵国(),吴新明,张良,孙恩慧,张海松,徐进良()   

  1. 华北电力大学低品位能源多相流与传热北京市重点实验室,北京 102206
  • 收稿日期:2018-06-26 修回日期:2019-01-04 出版日期:2019-04-05 发布日期:2019-04-05
  • 通讯作者: 徐进良
  • 作者简介:<named-content content-type="corresp-name">朱兵国</named-content>(1988—),男,博士研究生,<email>13919835339@163.com</email>|徐进良(1966—),男,博士,教授,<email>xjl@ncepu.edu.cn</email>
  • 基金资助:
    国家重点研发计划项目(2017YFB0601801);中央高校基本科研业务费专项资金(JB2018125)

Flow and heat transfer characteristics of supercritical CO2 in vertical tube

Bingguo ZHU(),Xinming WU,Liang ZHANG,Enhui SUN,Haisong ZHANG,Jinliang XU()   

  1. Beijing Key Laboratory of Multiphase Flow and Heat Transfer, North China Electric Power University, Beijing 102206, China
  • Received:2018-06-26 Revised:2019-01-04 Online:2019-04-05 Published:2019-04-05
  • Contact: Jinliang XU

摘要:

在压力为7.5~21 MPa,热通量为50~413 kW·m-2,质量流速为519~1500 kg·m-2·s-1的实验参数范围内,对超临界CO2在内径为10.0 mm的垂直上升管内的流动传热特性进行了均匀加热条件实验研究。分析了热通量、压力和浮升力对圆管内传热特性的影响规律。实验结果表明:随着热通量的增加,传热出现恶化现象,并且随着热通量的增加壁温峰值点向入口段移动。传热恶化发生在流体温度小于拟临界温度而壁面温度大于拟临界温度附近。增大压力时由于物性的变化趋于平缓,传热恶化被抑制。当传热恶化发生时,浮升力对传热恶化有明显的影响。基于实验数据,综合考虑物性变化和浮升力对传热的影响,建立了新的超临界二氧化碳传热关联式,在实验工况范围内,预测值与实验值的平均偏差和标准差分别为1.2%和16.29%。

关键词: 超临界二氧化碳, 流动, 传热关联式, 实验, 传热

Abstract:

The heat transfer characteristics of supercritical carbon dioxide in vertical upward tubes under uniform heating were studied experimentally. The inner diameter of the experimental section is 10 mm. The experimental parameters are: pressure 7.5—21 MPa, heat flux 50—413 kW·m-2, mass flux 519—1500 kg·m-2·s-1. The flow heat transfer characteristics in the riser tube were tested under uniform heating conditions. The effects of heat flux, pressure and buoyancy force on the heat transfer characteristics in the circular tube were analyzed. The results show that with the increase of heat flux the heat transfer deterioration occurs, and the peak point of wall temperature moves towards the inlet section. Heat transfer deterioration occurs when the fluid temperature is less than the pseudo-critical temperature and the wall temperature is greater than the pseudo-critical temperature. When increasing pressure, the deterioration of heat transfer is restrained due to the change of physical property tends to be gentle. Buoyancy forces are bad for heat transfer when heat transfer deterioration occurs. Based on the experimental data, the physical properties change and buoyancy influence on heat transfer are considered comprehensively, new supercritical carbon dioxide heat transfer correlations is established, within the range of the experiment condition, deviation from the mean and standard deviation of the predicted values and experimental values were 1.2% and 16.29% respectively.

Key words: supercritical carbon dioxide, flow, heat transfer correlation, experiment, heat transfer

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