Based on the concept of sustainable development, to promote the development and application of renewable energy and enhance the capacity of renewable energy consumption, this paper studies the design and optimization of renewable energy hydrogen production systems. For this paper, six different scenarios for grid-connected and off-grid renewable energy hydrogen production systems were designed and analyzed economically and technically, and the optimal grid-connected and off-grid systems were selected. Subsequently, the optimal system solution was optimized by analyzing the impact of the load data and component capacity on the grid dependency of the grid-connected hydrogen production system and the excess power rate of the off-grid hydrogen production system. Based on the simulation results, the most matched load data and component capacity of different systems after optimization were determined. The grid-supplied power of the optimized grid-connected hydrogen production system decreased by 3347 kWh, and the excess power rate of the off-grid hydrogen production system decreased from 38.6% to 10.3%, resulting in a significant improvement in the technical and economic performance of the system.

Liquid hydrogen storage is an important way of hydrogen storage and transportation, which greatly improves the storage and transportation efficiency due to the high energy density but at the same time brings new safety hazards. In this study, the liquid hydrogen leakage in the storage area of a hydrogen production station is numerically simulated. The effects of ambient wind direction, wind speed, leakage mass flow rate, and the mass fraction of gas phase at the leakage port on the diffusion behavior of the liquid hydrogen leakage were investigated. The results show that the ambient wind direction directly determines the direction of liquid hydrogen leakage diffusion. The wind speed significantly affects the diffusion distance. When the wind speed is 6 m/s, the diffusion distance of the flammable hydrogen cloud reaches 40.08 m, which is 2.63 times that under windless conditions. The liquid hydrogen leakage mass flow rate and the mass fraction of the gas phase have a greater effect on the volume of the flammable hydrogen cloud. As the leakage mass flow rate increased from 5.15 kg/s to 10 kg/s, the flammable hydrogen cloud volume increased from 5734.31 m³ to 10,305.5 m³. The installation of a barrier wall in front of the leakage port can limit the horizontal diffusion of the flammable hydrogen cloud, elevate the diffusion height, and effectively reduce the volume of the flammable hydrogen cloud. This study can provide theoretical support for the construction and operation of hydrogen production stations.

With the rapid development of hydrogen energy worldwide, the number of hydrogen energy facilities, such as hydrogen refueling stations, has grown rapidly in recent years. However, hydrogen is prone to leakage accidents during use, which could lead to hazards such as fires and explosions. Therefore, research on the safety of hydrogen energy facilities is crucial. In this paper, a study of high-pressure hydrogen jet flame accidents is conducted for a proposed integrated hydrogen production and refueling station in China. The effects of leakage direction and leakage port diameter on the jet flame characteristics are analyzed, and a risk assessment of the flame accident is conducted. The results showed that the death range perpendicular to the flame direction increased from 2.23 m to 5.5 m when the diameter of the leakage port increased from 4 mm to 10 mm. When the diameter of the leakage port is larger than 8 mm, the equipment on the scene will be within the boundaries of the damage. The consequences of fire can be effectively mitigated by a reasonable firewall setup to ensure the overall safety of the integrated station.

Hydrogen, as a renewable and clean energy carrier, has the potential to play an important role in carbon reduction. Crucial to achieving this is the ability to produce clean sources of hydrogen and to store hydrogen safely. With the rapid development of the hydrogen industry, the number of hydrogen refueling stations (HRS) is increasing. However, hydrogen safety at HRS is of great concern due to the high risk of hydrogen leakage during storage. This study focused on an integrated hydrogen production and refueling station (IHPRS) in Weifang, China, and numerically simulated a hydrogen leakage accident in its storage area. The effects of the leakage aperture, the leakage direction and the ambient wind direction and speed on the leakage and dissipation characteristics of hydrogen were investigated. The results showed that the volume, mass and dissipation time of the flammable hydrogen cloud (FHC) increased with an increase in the leakage aperture. The installation of a canopy or densely packed equipment near the hydrogen storage area will seriously hinder the dissipation of the FHC. Ambient winds in the opposite direction of the leakage may cause high-concentration hydrogen to accumulate near the hydrogen storage tanks and be difficult to dissipate, seriously threatening the safety of the integrated station.

Compared with gaseous hydrogen at ambient temperature, liquid hydrogen (LH₂) possesses a higher volumetric energy density and is therefore regarded as one of the most economically viable hydrogen storage and transportation options. However, the extremely large temperature difference between the storage temperature of LH₂ and the ambient environment may give rise to serious safety hazards once a leakage accident occurs. Focusing on an integrated hydrogen production and refueling station (IHPRS), this study investigates the suppression effect of a novel synergistic protection system—combining a barrier wall and an air curtain—on LH₂ leakage and dispersion. By comparing the dispersion distances of hydrogen clouds under different barrier wall–air curtain configurations, the optimal synergistic structure was identified as a barrier wall with a planar size of 36 m × 12 m and a height of 3 m, combined with an air curtain velocity of 40 m/s. The reliability of this structure is further evaluated under practical influencing factors: under varying natural wind conditions, the maximum downwind dispersion distance is reduced by up to 58.02%; at a flash evaporation mass fraction of 20%, horizontal dispersion is suppressed by 42.18% and 33.17% in the X- and Z-directions, respectively; and at a leakage mass flow rate of 5.15 kg/s, the X-direction dispersion distance is reduced by 33.88% with a 40.14% increase in cloud height. The results show that the proposed barrier wall–air curtain synergistic protection structure can effectively alter the dispersion path of the FHC (refers to the hydrogen cloud with a volume concentration within the flammable range between 4 and 75% vol) formed by LH₂ leakage, shorten the hazardous downwind distance, and enhance the vertical dispersion of the FHC. These findings provide theoretical support and safety guidance for the risk control of LH2 leakage accidents in IHPRS.