针对螺旋直径为736mm、1800mm的两套螺旋管在压力：P=0.44MPa~7.01MPa；质量流速：G=48.28kg/(m2·s)~1060.12kg/(m2·s)；热流密度：q=48.44kW/m2~493.48kW/m2等较宽的热工参数条件下，研究了管内流动沸腾干涸点，试验中选取螺旋管的内径Di=14mm，升角β=5.5°。通过实验研究了干涸时螺旋管壁面周向的温度变化特性，以及不同热工参数状态下干涸后壁面温度沿轴向的变化情况。同时，研究了热工参数（P、G、q）对临界干度的影响规律。结果表明，热工参数对干涸点的临界干度影响规律与直管保持一致，随质量流速增大而增大，随压力、热流密度增大而减小；最后根据实验结果对数据进行回归分析，拟合了临界干度实验关联式，平均偏差为4.51%，几乎所有数据点偏差在+10%以内。

The pressure of two sets of helical coils with spiral diameters of 736mm and 1800mm: pressure 0.44MPa~7.01MPa; Mass velocity 48.28kg/(m2·s)~1060.12kg/(m2·s); Heat fluxes 48.44kW/m2~493.48kW/m2 and other wide thermal parameters, the flow boiling dry point in the tube was studied. In the test, the inner diameter of the helical coils was selected as Di=14mm and the rising Angle β=5.5°.The circumferential temperature variation of the wall surface of the helical coils during drying and the axial temperature variation of the wall surface after drying under different thermal parameters were studied by experiments. At the same time, the influence of thermal parameters (P, G, q) on the critical quality of steam-water two-phase were studied. The results show that the influence of thermal parameters on the critical dryness of the dry point was consistent with that of the vertical pipes, and increases with the increase of mass velocity, but decreases with the increase of pressure and heat fluxes. Finally, according to the experimental results, the regression analysis of the data were carried out, and the experimental correlation of critical dryness was fitted. The mean deviation is 4.51%, and almost all data points are within +10%.