基于金属氢化物的单级氢压缩机的性能模拟

基于金属氢化物的氢压缩机是金属氢化物最有前途的应用之一。它具有从低温位热源中回收动力、对环境友好、安全可靠等优点。以LaNi5合金为氢压缩机的工质,建立了考虑壁面对流换热系数、合金导热系数、热源温度等因素的能量分析模型,应用有限容积法对描述反应床与储氢罐间的动态平衡过程进行了离散求解,综合分析了其操作工况的改变,对单级氢压缩机性能的影响,并提出了系统的优化措施。给定氢压缩机的压力比,氢压缩机存在最低热源温度;效率随热源温度的增加先增后减,冷源温度大约控制在285 K;给定冷、热源温度,合金导热系数与对流换热系数值亦存在最合适值;在给定工况及反应床尺寸下,储氢罐容积对压缩机性能有较大的影响。

Performance simulation of single-stage hydrogen compressor based on metal hydride

The metal hydride-based hydrogen compressor is studied.The energy analysis model is established using LaNi5 as working medium.The external heat transfer coefficient,effective thermal conductivity and heat source temperature are considered.The finite volume method is used to the discrete solution to the dynamic equilibrium process between reaction bed and hydrogen storage.The effect of operation variation on the performances of hydride compressor is analyzed.The optimization measures are suggested.At a given pressure ratio,the minimum temperature of the heat source is found for the hydrogen compressor.It is found that the efficiency increases and then decreases with the increasing of heat source temperature while the heat sink temperature is kept at about 285 K.There are optimal values of thermal conductivity and overall heat transfer coefficient at given hot and cold fluid temperatures.The hydrogen storage volume has significant influence on the compressor performance when the size of reactor is fixed.