新型双压Linde-Hampson氢液化工艺设计与分析

Design and analysis of a new type of dual-pressure Linde-Hampson hydrogen liquefaction process

为降低氢液化厂的生产能耗与投资成本,加快我国氢能商业化、民用化的发展,本文提出了一种采用液化天然气(LNG)预冷的新型双压Linde-Hampson(L-H)氢液化工艺系统。系统的设计液氢产量为5t/d,采用膨胀降温与换热冷却相结合的方法实现了对氢气的深冷。借助Aspen HYSYS软件对工艺流程展开了详细的模拟计算与分析,结果表明,该氢液化系统的比能耗为9.802kWh/kgH_(2),㶲效率为41.4%,系统的总㶲损失为1373.3kW,其中换热设备的㶲损失占主要部分;在对系统中关键参数进行的灵敏度分析中发现,氢气预压缩压力在2~4MPa范围内变化对液化系统的比能耗和氢气液化率影响较大,而LNG的加压压力对系统性能影响较小。新型氢液化工艺系统设备简单,投资成本较低,具备良好的液化性能,在未来中小型氢液化厂的建设中优势明显。

In order to reduce the production energy consumption and investment cost of hydrogen liquefaction plants and accelerate the development of hydrogen energy commercialization and civilian use in China,a novel dual-pressure Linde-Hampson(L-H)hydrogen liquefaction process using LNG pre cooling is proposed.The designed liquid hydrogen output of the system is 5t/d and the method combining expansion and cooling with heat exchange is adopted to realize deep cooling of hydrogen.Aspen HYSYS software is used to carry out detailed simulation calculation and analysis for the process.The results show that the specific energy consumption and exergy efficiency of the hydrogen liquefaction process are 9.802kWh/kgH_(2)and 41.4%,respectively,and the total exergy loss of the process is 1373.3kW,of which the exergy loss of the heat exchange system accounts for the main part.It is found from the sensitivity analysis of the key parameters in the process that the change of the pre-compression pressure of the hydrogen in the range of 2-4MPa has a greater impact on the specific energy consumption and hydrogen liquefaction rate of the liquefaction process,while the pressure of LNG has little impact on the system.The novel hydrogen liquefaction process has simple equipment,low investment cost,and better liquefaction performance.It has advantages in the construction of small and medium-sized hydrogen liquefaction plants.