直接蒸汽光热发电系统中相变换热器的传热特性研究  

Study on Heat Transfer Characteristics of Phase Change Heat Exchanger in Direct Steam Photothermal Power Generation System

作　　者：王文昭 郑乐飞 邓雅军 宇波[1] 孙东亮[1] WANG Wenzhao;ZHENG Lefei;DENG Yajun;YU Bo;SUN Dongliang(School of Mechanical Engineering, Beijing Institute of Petrochemical Technology, Beijing 102617, China)

机构地区：[1]北京石油化工学院机械工程学院,北京102617

出　　处：《北京石油化工学院学报》2022年第2期10-16,共7页Journal of Beijing Institute of Petrochemical Technology

摘　　要：针对直接蒸汽管壳式相变换热器数值模拟研究通常不考虑自然对流存在和与实际物理过程存在差异的问题,建立了考虑自然对流影响的直接蒸汽相变换热器模型。其中,内管饱和蒸汽的冷凝过程采用VOF模型与Lee模型相结合的计算方法,外管相变材料区域采用焓-孔隙率法。分析了不考虑自然对流时与考虑自然对流直接蒸汽相变换热器的传热特性。研究结果表明,考虑自然对流时内管出口处蒸汽的冷凝量大幅增加,出口蒸汽质量分数显著降低,相变材料融化时间减少了约30%。因此,在直接蒸汽相变蓄热器的数值模拟中,自然对流作用不可忽略。The modeling of shell-and-tube phase change heat exchanger for the direct steam generation usually does not consider the effect of the natural convection in the previous studies,which is different from the actual physical process.To overcome this issue,a numerical model considering the natural convection is established in the current work.The condensation process of saturated steam is modeled using the VOF model and Lee model,while the melting and solidification process of phase change material(PCM)is modeled using the enthalpy-porosity method.The heat transfer characteristics of shell-and-tube phase change heat exchanger for direct steam generation are studied,with and without considering the natural convection.The research indicates that the condensing amount of the steam at the outlet increases significantly after considering the natural convection.Accordingly,the mass fraction of the steam at the outlet decreases significantly,which reduces the melting time of the PCM by about 30%.Therefore,considering the natural convection effect is necessary for the numerical simulation of the shell-and-tube phase change heat exchanger for direct steam generation.

关 键 词：太阳能直接蒸汽发电 相变蓄热 管壳式换热器 自然对流 传热特性 

分 类 号：TK512[动力工程及工程热物理—热能工程]