The intermediate fluid vaporizer (IFV) is a typical vaporizer of liquefied natural gas (LNG), which in general consists of three shell-and-tube heat exchangers (an evaporator, a condenser, and a thermolator). LNG is heated by seawater and the intermediate fluid in these heat exchangers. A one-dimensional heat transfer model for IFV is established in this paper in order to investigate the influences of structure and operation parameters on the heat transfer performance. In the rated condition, it is suggested to reduce tube diameters appropriately to get a large total heat transfer coefficient and increase the tube number to ensure the sufficient heat transfer area. According to simulation results, although the IFV capacity is much larger than the simplified-IFV (SIFV) capacity, the mode of SIFV could be recommended in some low-load cases as well. In some cases at high loads exceeding the capacity of a single IFV, it is better to add an AAV or an SCV operating to the IFV than just to increase the mass flow rate of seawater in the IFV in LNG receiving terminals.

中间流体蒸发器（IFV）是典型的液化天然气（LNG）蒸发器，通常由三个管壳式换热器（蒸发器，冷凝器和热化器）组成。在这些热交换器中，LNG由海水和中间流体加热。为了研究结构和运行参数对传热性能的影响，建立了IFV的一维传热模型。在额定条件下，建议适当减小管径以获得较大的总传热系数，并增加管数以确保有足够的传热面积。根据仿真结果，尽管IFV容量远大于简化IFV（SIFV）容量，但在某些低负载情况下也可以建议使用SIFV模式。