多相混输体系析蜡热力学研究进展

Thermodynamics Study Progress of Wax Precipitation in Multiphase System

针对海底多相混输体系析蜡问题,开展了蜡热力学预测模型及析蜡实验测量方法的研究。通过对Won模型、Ji模型等析蜡热力学预测模型的分析,认为热力学预测模型的建立过程中需考虑到液相描述一致性、固–固转变、纯组分热力学性质、Poynting修正项处理以及活度系数计算等问题。并对可用于多相体系析蜡实验测量的激光法、超声波法、声共振法、石英晶体微天平法以及高压微差示扫描量热法等进行了分析研究。认为石英晶体微天平法因其较高的灵敏性,高压微差示扫描量热法因其简便、耗样量少、再现性好且测试过程中基本避免了人为因素的影响,具有较好的应用前景。

Wax precipitation in multiphase system was studied with wax thermodynamic models and experiment methods in view of sea floor transportation system. Based the analysis of the wax thermodynamic models of Won and Ji’s,the consistency of calculation method selecting of liquid phase fugacity in vapor-liquid equilibrium and liquid-solid equilibrium,solid-solid transition,the thermodynamic properties of pure components,Poynting correction term treatment,as well as activity coefficient calculation should be considered when a new model is built. Experimental measurement methods,such as laser method, ultrasonic method,acoustic resonance method,quartz crystal microbalance method（QCM）,high-pressure micro-differential scanning calorimetry method（HP-μDSC）,which can be used to the analysis of the multiphase system. The results show that quartz crystal microbalance method has good prospect because of its high sensitivity,and high-pressure micro-scanning calorimetry method because of its easy conduction,small sample consumption,good reproducibility and almost no influence of human factors in the testing process.