PFHE型五级液氮预冷氢膨胀与四级氦膨胀氢液化工艺研究

Research on H_(2) liquefaction process of H_(2) expansion with pre-cooling by LN_(2) in five-stage PFHE&H_(e) expansion in four-stage PFHE

研究了以板翅式换热器(PFHE)为核心的30万方/天五级液氮(LN_(2))预冷氢膨胀制冷氢液化系统和四级氦膨胀制冷氢液化系统的原理和工艺流程,两种氢液化工艺均可将氢气液化为-252℃的液氢(LH_(2));给出了两种氢液化工艺具体参数和主液化装备板翅式换热器的设计计算方法;借助制冷效率、压力损失等主要参数理论计算和两种工艺的特点进行优劣对比。研究表明:针对30万方/天PFHE型氢液化工艺,液氮预冷氢膨胀制冷氢液化工艺制冷效率高、压力损失少、集约性好、可同时制取液氢和液氮两种低温工质,但系统工艺复杂,设备数量众多;氦膨胀制冷氢液化工艺流程简单,功能单一,但集约性差。

30×10^(4)Nm^(2)/d H_(2)liquefaction process of H_(2)expansion with pre-cooling by liquid nitrogen(LN_(2)) in five-stage plate-fin heat exchanger(PFHE) & H_(2)expansion in four-stage PFHE was researched.Both liquefaction processes can liquefy H_(2)to liquid hydrogen(LH_(2)) in-252℃.The specific process parameters of the two H_(2)processes and the design and calculation methods of the main PFHEs were given separately.The advantages and disadvantages of the two processes were compared by the theoretical calculation of main parameters such as refrigeration efficiency and pressure loss.Based on 30×10^(4)Nm^(2)/d H_(2)liquefaction process,the result shows the process of H_(2)expansion with pre-cooling by LN_(2)in five-stage PFHE has the advantages of high refrigeration efficiency,less pressure loss and good intensification,which can produce LN_(2)and LH_(2)at the same time,but the system process is complex and the number of equipment is large.The process of H_(2)expansion in four-stage PFHE is simple,single function,but poor intensification.