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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,热流密度越大,传热系数越高。压力对煤油传热影响不大,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。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。
The heat transfer characteristics of aviation kerosene under vertical supercritical pressure in vertical riser were studied experimentally. The effects of different mass flow rate, heat flux density, pressure and inlet temperature on the heat transfer characteristics of aviation kerosene under supercritical pressure were analyzed. The experimental results show that both the mass flow rate and the inlet temperature improve the heat transfer effect of kerosene. The effect of heat flux on heat transfer is mainly due to the change of fluid and wall temperature. The higher the heat flux, the higher the heat transfer coefficient. Pressure on the heat transfer of kerosene has little effect, under normal circumstances, to increase the pressure will deteriorate heat transfer. In the supercritical state, the physical properties of kerosene vary greatly. Therefore, the accurate calculation of kerosene transport and thermodynamic properties is the key to study the heat transfer phenomenon under supercritical pressure. The extended contrast method is used to calculate the density and transmission characteristics of kerosene, such as viscosity and thermal conductivity. The heat transfer relation of kerosene under supercritical pressure is given, and the calculated value is in good agreement with the experimental data.