复叠制冷辅助预冷的氢液化工艺设计与研究

Design and study of hydrogen liquefaction process auxiliary precooling by cascade refrigeration

针对氢液化过程中能耗过高问题提出一种新型氢液化工艺。在混合制冷剂预冷的氢液化工艺基础上,增设了CO_(2)/NH_(3)复叠制冷系统辅助预冷,以及逐级实现正-仲氢转化的四个转化器。以50吨/天的氢液化工艺为例,利用Aspen HYSYS软件,对新工艺进行了仿真研究。同时以单位能耗为目标函数优化,总结得出:新工艺单位能耗为6.93 kWh/kgLH_(2),效率高达54.24%;工艺流程中的换热器和反应器损失较大,分别为28.75%和30.47%。

A new type of hydrogen liquefaction process was proposed to solve the problem of high energy consumption in the hydrogen liquefaction process.Based on the hydrogen liquefaction process of pre-cooled mixed refrigerant,the CO_(2)/NH_(3) cas-cade refrigeration auxiliary system was added,as well as four ortho-to-para hydrogen conversion reactors.Taking the liquefac-tion process of 50 tons/day of hydrogen as an example,a simulation study on the new process was carried out using Aspen HYSYS software.At the same time,the unit energy consumption was optimized as the objective function,and it is concluded that the process specific energy consumption(SEC)is 6.93 kWh/kgLH_(2),and the exergy efficiency is as high as 54.24%;the exer-gy losses of the heat exchanger and the conversion reactor in the liquefaction process are relatively large,28.75%and 30.47%,respectively.