Performance assessment of an integrated absorption cooling–hydrogen liquefaction system using geothermal energy

An integrated geothermal based triple effect absorption cooling and Linde–Hampson system for hydrogen gas liquefaction is proposed and analysed thermodynamically. The effect of various operating conditions and parameters on the system performance is studied. The results show that the mass of hydrogen gas pre–cooled by the absorption system per unit mass flow rate of geothermal water flowing through the system (n) and the amount of hydrogen liquefied per unit mass flow rate of geothermal water flowing through the system (y) increase with an increase in the geothermal source temperature. Also, both energetic and exergetic coefficients of performance decrease from 1.33 to 0.12 and 0.92 to 0.08, respectively with an increase in the mass flow rate of geothermal water from 1.5 kg/s to 3.0 kg/s. The energetic and exergetic utilisation factors decrease from 0.06 to 0.009 and 0.19 to 0.006, respectively as the mass flow rate of geothermal water increases.

Keywords: hydrogen gas liquefaction, exergy efficiency, energy efficiency, geothermal energy, absorption cooling systems, performance evaluation