Optimization and analysis of a novel hydrogen liquefaction process for circulating hydrogen refrigeration

In industrial engineering, hydrogen is usually transported and stored after being liquefied, which is an energy-intensive process. Aiming to liquefy hydrogen with high efficiency and low consumption, a novel hydrogen liquefaction process based on dual-path hydrogen refrigeration is proposed innovatively and simulated by Aspen HYSYS to determine the key parameters. Taking the specific energy consumption (SEC) as the objective function for the optimization by genetic algorithm (GA), optimum parameters could be obtained. Meanwhile, the single variable method is conducted to analyze the impact of key parameters on process characteristics. Under the premise of complete liquefaction, the SEC, coefficient of performance (COP) and exergy efficiencies (EXE) of the proposed system are 7.041 kWh/kg LH2, 0.1834, 0.5413, respectively. Compared with the other three hydrogen liquefaction systems simulated under the same conditions, they are decreased by 22.16% and increased by 33.58% and 42.37%, respectively. The results show that the proposed system shows better performance under lower consumption.