Abstract:

In order to predict the dynamic performance of spiral wound heat exchanger applied in LNG Floating Production Storage and Offloading(LNG-FPSO),a multi-zone dynamic model of multi-stream LNG spiral wound heat exchanger was developed.A mathematic method by establishing 3(n+1)×3(n+1)diagonal matrices and interconnection matrices was proposed to express parameters in heat transfer calculation of multi-stream heat exchanger,which is capable of describing the heat transfer relationship between each stream and each zone.A heat transfer calculation model for fluid and tube wall based on multi-zone method was presented,considering the staggered arrangement of phase interface,which is capable of calculating heat transfer in the case of phase changes in both cold and hot streams.Case study showed that the presented model could be applied for dynamic simulation of multi-stream spiral wound heat exchanger,and was feasible to handle the transposition of phase interface.The results of presented model agreed well with the existed model,and the validation deviation was less than 4%.

Key words: spiral wound heat exchanger, heat transfer, flow, multi-stream, multi-zone, dynamic modeling, LNG

摘要：

为预测海上浮式天然气生产储卸平台(LNG-FPSO)中绕管式换热器的动态特性,建立了一种分相的多股流LNG绕管式换热器动态模型。采用二维矩阵的描述方法建立了行列数为3(n+1)×3(n+1)的对角矩阵和互连矩阵,对多股流换热器传热计算中的物理参量进行数学表达,实现了多股流多相区换热关系的描述。采用分相区的建模方法提出了相边界交错排列下流体与管壁的传热模型和管壁温度的计算模型,实现了冷热流体在并发相变时的传热计算。实例表明该模型能够计算多股流形式的绕管式换热器,并能处理相边界"交错"的情况。与已发表的模型进行仿真对比,计算结果吻合良好,最大偏差小于4%。

关键词: 绕管式换热器, 传热, 流动, 多股流, 分相, 动态建模, LNG