竖直方管内两相流动临界热流密度的实验研究

Experimental study on critical heat flux of two-phase flow in a vertical square tube

本实验以氟利昂-113作为工作流体,对竖直方管内向上两相流动的临界热流密度(Critical Heat Flux,CHF)进行了实验研究.实验主要参数的范围为:质量流速650～1 800kg/(m2s);进口压力380～550kPa;入口干度,过冷～1.0.重点分析了质量流速,压力,进出口干度对CHF值的影响.实验结果表明:CHF值随质量流速的增大而增大,随压力的升高有所减小,随进口干度的增加基本呈现线性下降趋势,同时在发生临界热流现象后,出口干度基本保持不变.

An experimental study was conducted on the critical heat flux of two-phase upward flow in a vertical square tube, using Freon-ll3 as the working fluid. The main parameters of experiment were performed with the mass velocity ranging from 650 to 1 800 kg/（m2 s）, the inlet pressure from 380 to 550 kPa, and the inlet dryness from super-cooling to 1.0. The effects of mass velocity, pressure and dryness on the critical heat flux were obtained in this paper. The results show that CHF values increase with the mass velocity, CHF values have been reduced when the pressure or the inlet dry- ness increases, and the outlet dryness hardly change after the critical heat flux phenomena occur.