液氮预冷双路循环氢液化系统优化与分析

Optimization and Analysis of Liquid Nitrogen Precooling Dual Cycle Hydrogen Liquefaction System

为降低大型氢液化工程的生产能耗,推动我国氢能产业的发展,本文提出一种液氮预冷双路循环紧凑新型氢液化系统。系统最大液氢产量为300 t/d,采用节流降温、膨胀降温和换热冷却的方式实现氢气深冷液化。通过对氢气物性计算进行优选,借助Aspen HYSYS软件对工艺流程进行模拟计算和分析。采用Matlab调用遗传算法对氢液化系统中的关键参数进行全局优化后,比能耗为6.274 kWh/kg LH2,㶲效率为33.79%;考虑到液氮的制取能耗,液化系统的总比能耗为10.59 kWh/kg LH2,㶲效率为19.99%;优化后的氢液化系统具有更好的运行性能。同时,基于优化结果分析设备㶲损和换热器性能,可为大型氢液化装置的研发提供重要参考。

In order to decrease the energy consumption in the production of large-scale hydrogen liquefaction projects and facilitate the growth of China’s hydrogen energy industry,we propose a compact novel hydrogen liquefaction system that employs liquid nitrogen pre-cooling with dual-loop circulation.The system has a maximum liquid hydrogen production capacity of 300 t/d.Hydrogen can be deeply cryogenically liquefied through throttling cooling,expansion cooling,and heat exchange cooling.Optimization of hydrogen gas properties calculation is performed,and the process flow is simulated and analyzed with Aspen HYSYS software.Global optimization of key parameters in the liquefaction process is conducted using the genetic algorithm in Matlab.The optimized results showed that the specific energy consumption was reduced to 6.274 kWh/kg LH2,with an exergy efficiency of 33.79%.Taking into account the energy consumption for liquid nitrogen production,the total specific energy consumption of the liquefaction system was determined to be 10.59 kWh/kg LH2,with an exergy efficiency of 19.99%.The optimized liquefaction system exhibited improved operational performance.Furthermore,based on the optimization results,an analysis of equipment exergy losses and heat exchanger performance was conducted,providing valuable insights for the development of large-scale hydrogen liquefaction plant.