制冷剂在微通道扁平T型管内的气液两相流相分配特性研究

气液两相流在常规T型管内的相分配特性已得到充分研究，但少有文献关注微通道扁平T型管内的两相流分配特性。以两相制冷剂R134a为工质，对扁平T型管内的相分配特性进行了实验研究。实验结果表明，气液两相流在扁平T型管内的液相进口流速增加会使液相分离比减小，气相分离比增大；进口干度增加使液相分离比增大，气相分离比减小；气相进口流速对扁平T型管内泡状流的相分配影响较小。由相分配模型预测值与实验值对比可知，现有的相分配模型还无法准确预测扁平T型管内泡状流的气液相分离比。在进口干度为0.45~0.5时扁平T型管内制冷剂R134a气液相分配比较均匀。

Study on phase distribution characteristics of gas-liquid two-phase flow in micro-channel flat T-junction

The phase distribution characteristics of gas-liquid two-phase flow in conventional T-junction have been fully studied, but few literatures have paid attention to the distribution characteristics of two-phase flow in micro-channel flat T-junction. Using the two-phase refrigerant R134a as the working fluid, the phase distribution characteristics in the flat T-junction are studied experimentally. The results show that the increase of the liquid-phase inlet flow rate of the two-phase flow in the flat T-junction will decrease the liquid-phase separation ratio and increase the gas-phase separation ratio. The increase of the inlet quality will increase the liquid-phase separation ratio and decrease the gas-phase separation ratio. The gas inlet velocity has little effect on the phase distribution of the bubbly flow in the flat T-junction. It can be seen from the comparison between the predicted phase distribution model and the experimental value that the existing phase distribution model cannot accurately predict the gas-liquid separation ratio of the bubbly flow in the flat T-junction. In the experimental conditions, when the inlet dryness is 0.45—0.5, the refrigerant R134a in the flat T-junction has a relatively uniform gas and liquid distribution.