基于汽泡壅塞流模型的竖直圆管临界热流密度理论研究

Theoretical Research on Critical Heat Flux of Vertical Tube Based on Bubbly Crowding Model

为研究单管壅塞流的临界热流密度(CHF)现象,建立了基于近壁处汽泡壅塞机理的CHF计算模型。模型通过求解相应的质量、动量和能量方程,再结合汽泡直径脱离模型、壁面临界空泡份额等模型,从而计算得到CHF。将模型计算结果同实验值比较,吻合良好,验证了模型的正确性。在此基础上,以建立的CHF模型为基础,研究了进口焓差、质量流速、管径和加热长度对CHF的影响,为预测壅塞流CHF提供依据。

To study the single pipe CHF phenomenon of the bubble crowding, the CHF calculation model was developed based on the near wall bubble crowding mechanism model. The CHF was obtained by solving the mass, momentum and energy equation together with bubbly detaching model and critical void fraction model in the near wall. The results calculated by the model were compared with the experimental data and a good agreement was achieved. Based on the CHF calculation model, the CHF varing with the inlet enthalpy difference, mass flow rate, diameter and length was studied, which could be used to predicting the bubbly crowding CHF.