超临界压力下航空煤油在竖直管内的传热研究

Experimental study on heat transfer of supercritical kerosene in vertical upward tube

中文关键词: 超临界压力,煤油,传热特性,对比态法

英文关键词: Supercritical pressure  kerosene  heat transfer  corresponding-state

中文摘要:

      对竖直上升管内超临界压力下航空煤油的传热特性进行了实验研究。分析了不同质量流量、热流密度、压力和进口温度对超临界压力下航空煤油传热特性的影响。实验结果表明,提高质量流量或进口温度均使煤油传热效果变好。而热流密度对流体传热的影响主要在于改变了流体和壁面温度,本文中热流密度越大,传热系数越高。压力对煤油换热影响不大,一般情况下,提高压力会恶化传热。超临界状态下,煤油物性变化很大,因此对煤油的传输和热力学性质的准确计算是研究超临界压力下传热现象的关键。本利用拓展的对比态法来计算煤油的密度和传输特性,如黏度、热导率等。给出了煤油在超临界压力下的传热关联式,其计算值和实验值吻合良好。

英文摘要:

      A research on the heat transfer performance of kerosene flowing in a vertical upward tube at supercritical pressure is presented. In the experiments, insights are offered on the effects of the factors such as mass flow rate, heat flux, pressure and inlet temperature. The results show that increasing mass flow rate or inlet temperature can enhance the heat transfer. The effect of heat flux on heat transfer lies in the changes of inner wall or fluid temperature. In this paper, heat transfer coefficient increases with increasing heat flux. The heat transfer will be deteriorated by increasing pressure. At the supercritical conditions, heat transfer is influenced by the significant changes in thermo-physical properties, thus accurate evaluations of the thermo-physical properties become the key for the supercritical heat transfer calculations. The extended corresponding-state principle could be used for evaluating the density and the transport properties of kerosene, including its viscosity and thermal conductivity, at different temperatures and pressures. The correlation for predicting heat transfer in kerosene at supercritical pressure is established,the calculation results from this correlation are in good agreement with the experimental results.