LNG vaporizer is widely used all over the world to vaporize LNG by using seawater. An intermediated fluid type vaporizer (IFV) uses intermediated fluid between LNG and heat source to transfer heat, and is enable to utilize LNG cold energy for a cryogenic power generation, and so on. Conventionally propane has been used as an intermediated fluid; however, refrigerants other than propane are recently needed because of the diversified usage environments. In this study, R32 and R410A are selected and their feasibility is discussed in heat transfer aspect. By using a number of unit (NTU) method, prediction of boiling and condensation heat transfer rate in tube bundles was carried out. The prediction demonstrated that those selected refrigerants can increase the vaporization rate with IFV from the base line of propane. From those, feasibility of refrigerant use in IFV was shown.

LNG气化器在世界范围内被广泛用于通过使用海水气化LNG。中间流体型汽化器（IFV）使用LNG和热源之间的中间流体来传递热量，并且能够利用LNG冷能来进行低温发电等。常规上，丙烷已被用作中间流体。但是，由于使用环境的多样化，最近需要丙烷以外的制冷剂。在这项研究中，选择了R32和R410A，并在传热方面讨论了它们的可行性。通过使用多个单位（NTU）方法，对管束中的沸腾和冷凝传热速率进行了预测。预测表明，这些选定的制冷剂可以提高丙烷基线的IFV蒸发速率。从那些，