超临界CO2及其混合物在竖直圆管内的传热特性数值研究

Numerical Study on Heat Transfer Characteristics of Supercritical CO2 and Its Mixture in Vertical Circular Tubes

葛韶华 艾贵琳 杨帆 陈昊楠 屈思雨 姜文全

Shaohua Ge Guilin Ai Fan Yang Haonan Chen Siyu Qu Wenquan Jiang

辽宁石油化工大学 机械工程学院，辽宁 抚顺 113001 辽宁石油化工大学 石油天然气工程学院，辽宁 抚顺 113001

School of Mechanical Engineering，Liaoning Petrochemical University，Fushun Liaoning 113001，China College of Petrochemical Engineering，Liaoning Petrochemical University，Fushun Liaoning 113001，China

碳捕捉、运输和储存（CCS）对实现碳中和具有重要意义。以超临界CO2、超临界CO2+CH4混合物（CH4摩尔分数分别为1%、3%、5%）及超临界CO2+N2混合物（N2摩尔分数分别为1%、3%、5%）为工质，在工质质量流速为300～600 kg/（m2?s）、热流密度为80～100 kW/m2、入口压力为8～10 MPa的条件下，研究了超临界CO2及超临界CO2混合物在竖直圆管内的流动换热过程。结果表明，随着工质中CH4和N2摩尔分数的降低，工质的换热系数峰值逐渐升高，且其对应的温度逐渐升高；工质的换热系数随着质量流速的增大而增大，且质量流速越大，换热系数变化幅度越大；随着入口压力的增大，工质的换热系数峰值有所降低，且其对应的温度逐渐升高；湍动能、浮升力及定压比热容与超临界CO2及其混合物换热强化密切相关。

Carbon capture, transport and storage (CCS) plays an important role in the process of carbon neutralization. The flow and heat transfer process of supercritical CO2 and supercritical CO2 mixture in a vertical circular tube was studied with supercritical CO2, supercritical CO2+CH4 mixture (CH4 mole fraction is 1%, 3%, 5%) and supercritical CO2+N2 mixture (N2 mole fraction is 1%, 3%, 5%) as working fluids at a mass flow rate of 300～600 kg/(m2?s), heat flow density of 80～100 kW/m2, and inlet pressure of 8～10 MPa. The results show that with the decrease of CH4 and N2 mole fraction in the working medium, the peak value of heat transfer coefficient of the working medium increases gradually, and its corresponding temperature increases gradually; the heat transfer coefficient of the working fluid increases with the increase of the mass flow rate, and the greater the mass flow rate, the greater the change range of the heat transfer coefficient; with the increase of inlet pressure, the peak value of heat transfer coefficient of working fluid decreases, and its corresponding temperature increases gradually. Turbulent kinetic energy, buoyancy and specific heat capacity at constant pressure are closely related to the heat transfer enhancement of supercritical CO2 and its mixture.

辽宁省自然科学基金项目(20170540587);辽宁省教育厅科学研究经费项目(L2019024)

10.12422/j.issn.1672-6952.2023.03.012