Development of an integrated structure of hydrogen and oxygen liquefaction cycle using wind turbines, Kalina power generation cycle, and electrolyzer

Conventional methods of energy storage are not able to provide long-term storage due to practical and economic constraints. One of the leading methods for long-term energy storage is the use of wind energy to liquefy hydrogen and oxygen. In this study, an integrated structure of hydrogen liquefaction is developed using the wind turbines, Kalina power generation cycle, and electrolyzer. The HYSYS and TRNSYS software packages with MATLAB programming are used to simulate the hydrogen and oxygen liquefaction structure, considering the weather conditions of the province of Newfoundland and Labrador (NL), Canada. This integrated structure produces 2100 kgmol/h of liquid hydrogen by receiving 264.1 MW of power from wind turbines. The waste heat of the hydrogen liquefaction cycle is used to supply the Kalina power generation cycle. Thermal (or energy) integration can reduce the power consumption of the integrated structure by 8.61%. The specific energy consumption, coefficient of performance of the hydrogen liquefaction cycle, and energy efficiency of the Kalina cycle are obtained to be 5.462 kWh/kgH(2), 0.1384, and 14.06%, respectively. The overall exergy efficiency and total irreversibilities are 58.73% and 112.7 MW, respectively. The exergy analysis of the integrated structure shows that the highest exergy destruction occurs in electrolyzers (83.13%) and heat exchangers (5.93%), respectively. Also, by adding oxygen liquefaction flow to the integrated hydrogen liquefaction cycle, the specific energy consumption and total exergy efficiency are determined to be 1.632 kWh/kg liquids and 59.11%, respectively. The sensitivity analysis to investigate the effects of the important variables on the performance of the integrated structure is also performed. (c) 2020 Elsevier Ltd. All rights reserved.