蒸汽压缩蒸馏装置共轭传热过程的数值模拟

Numerical Simulation on Vapor-Compression Distillation Apparatus in Process of Conjugate Heat Transferring

蒸汽压缩蒸馏装置(VCD)是国际空间站从尿液废水中回收纯净水的重要装置。首次考虑离心力及微重力环境共同作用下两相流动、相变传热、汽液分离多因素耦合对VCD装置产水效率的影响,采用Fluent多相流混合模型,通过开发自定义函数(UDF),将相变潜热嵌入能量方程数值模拟了VCD装置共轭换热的相变过程,得到了不同时刻下蒸发器、冷凝器内气液两相体积分布及相变过程的传热特性、流动状态;在此基础上模拟了不同进口流量下该装置的产水率值,得出了产水率随进口流量的变化规律。模拟结果和国外文献提供数据对比,两者相对吻合,从而为蒸汽压缩蒸馏装置的整体设计提供了可靠的参考。

Vapor-compression distillation （VCD） apparatus is an important device that recycles purified water from waste water in international space stations.In this paper,the affection on water-recycling efficiency of VCD device by multi-factor coupling was firstly taken into consideration,including two-phase flow,phase-change heat transferring and liquid-vapor separation under the combined excitation of centrifugal force and microgravity.Applying Fluent multi-phase flow model and developing the user defined functions（UDF）,the embedded energy equation numeric of latent heat of phase change was used to simulate the phase-changing process of the conjugate heat transferring of the VCD apparatus,which achieved the vapor-liquid two-phase volume distribution and the heat-transfer characteristic and flow status in the evaporators and condensers at different moment.On the basis of the conditions mentioned above,the water production rate of the device under variable inlet was simulated,by which the varying rule due to inlet flow rate was obtained.Comparing the simulation results with the values provided by overseas references,the values match with each other,which provides reliable references for the entire design of VCD apparatus.