首次报道在 1 0 0℃的较高温度时 ,同一流体体系同时出现两类异常相变现象。应用无汞PVT相态实验装置测试了多组分烃类流体临界点 ,详细描述了流体近临界相态特征。在实验测试过程中 ,发现流体在近临界区域存在特殊的相变现象 :流体在温度高于临界温度时的恒质膨胀过程中先后发生了两次反凝析露点变化 ,即“露—露”相变 ;在低于临界温度时也先后发生了两次先出现露点后出现泡点的相变现象 ,即“露—泡”相变。在上述两个异常相变过程中 ,先出现的液相体积较少 ,且液相在不同温度条件下消失时的压力相同。实验中发现的异常相态变化现象说明多组分流体相态变化的复杂性 ,这可能对复杂流体体系的近临界特征作出新解释 ,同时也说明通常相态计算中两相假设的局限性。照片 1 6图 3参 1 9 It was first reported that at the higher temperature of 100 ℃, two types of abnormal phase transitions occurred simultaneously in the same fluid system. The critical point of multi-component hydrocarbon fluid was tested by using mercury-free PVT phase state experimental device, and the near-critical phase behavior of the fluid was described in detail. During the experimental test, it was found that there was a special phase transition in the near-critical region of the fluid: two decondensation dew point changes occurred during the constant expansion of the fluid at a temperature higher than the critical temperature, ie, “dew-dew” Phase transition; below the critical temperature has also occurred twice before the dew point appeared bubble point phase change phenomenon, that is, “dew - bubble” phase transition. During the above two abnormal phase transitions, the volume of the liquid phase that appears first is less and the pressure of the liquid phase disappears at the same temperature. The phenomenon of abnormal phase change found in the experiment shows the complexity of the phase change of multi-component fluid, which may make a new explanation for the near-critical characteristics of complex fluid system and also illustrates the limitations of the two-phase assumption in the usual phase calculation. Picture 1 6 Picture 3 参 1 9